CN117484482A - Three-degree-of-freedom joint driver with multi-drive hierarchical output and ball center rotation - Google Patents

Abstract

The invention discloses a three-degree-of-freedom joint driver with multi-drive hierarchical output and spherical center rotation, which comprises the following components: a motor portion, a gear portion, and an output shaft. The motor part comprises a left motor, a middle motor and a right motor; the gear part comprises a differential bevel gear assembly and a spherical gear assembly, the differential bevel gear assembly is connected with the left motor and the right motor, and the spherical gear assembly is connected with the middle motor; one end of the output shaft is coupled with the differential bevel gear assembly and the spherical gear assembly. The input power of the left motor and the right motor is transmitted to the output shaft through the differential bevel gear assembly, the input power of the middle motor is transmitted to the output shaft through the spherical gear assembly, and therefore graded power output is achieved, and the movement track surface of the output shaft is spherical. The invention can realize three-degree-of-freedom rotary motion with high energy density, high mechanical efficiency, spherical actuator motion trail and no mechanical structure compromise under the compact appearance, and realize the imitation of the hip joint motion.

Description

Three-degree-of-freedom joint driver with multi-drive hierarchical output and ball center rotation

Technical field

The invention relates to the technical field of joint actuators, and in particular to a three-degree-of-freedom joint actuator with multi-drive hierarchical output and ball center rotation.

Background technique

As core power equipment, joint actuators are widely used in powered exoskeletons, humanoid robots, and mechanical hip joints. A feasible research idea is to abandon the traditional hip joint actuator research idea and propose a new joint actuator form based on bionics to achieve an overall closeness of the artificial joint actuator to the human hip joint in terms of driving performance, sports performance, and control logic.

According to a summary of existing actuator research results, it can be seen that high-performance joint actuators are a necessary prerequisite for the study of high-performance prostheses, powered exoskeletons, humanoid robots, and mechanical hip joints. Only by achieving breakthroughs in core equipment can the performance of the intelligent equipment proposed based on this be guaranteed. Great improvement. Taking the existing actuator research results as an example, the current focus of joint actuators in academic circles is: high power density and mechanical efficiency output, high mechanical structure compactness and modularity, wide range of motion capabilities, and high dynamic response. The human hip joint still maintains the optimal performance of the above-mentioned properties. If the core factors of the biomechanical advantages of the human hip joint can be extracted, engineering practice driven by bionics models can be realized, and then bionic motion modes suitable for new actuators can be proposed. and provide new ideas for control methods.

The current research and development focuses and difficulties of hip joints mainly include: high power density and mechanical efficiency output, high mechanical structure compactness and modularity, high dynamic response, and wide range of motion capabilities. At present, artificial hip joint actuators are still mainly based on the traditional series combination of actuators. There has been no essential breakthrough in its form for a long time, and its key performance indicators are still far behind the human hip joint. Existing joint actuators mainly have the following three problems:

First of all, in terms of driving power (dynamics), current artificial power hip joints are basically three-axis independent drives, and each motor only drives its own corresponding rotational degree of freedom. Even in medical robots and surgical robotic arms, the output power required for each degree of freedom is not uniform and constant just like human joints. This makes it possible that when a mid-range power motor is used, power redundancy may occur when the rotational freedom is light-loaded, and insufficient power may occur when the rotational freedom is heavy-loaded, making it impossible to achieve high energy density output and maintain a high energy density. mechanical efficiency. In the engineering community, in order to cover the maximum load degree of freedom, motors are generally selected according to the highest load, which may lead to a waste of power density in some degrees of freedom of the motor. Moreover, since the motor does not work during all action periods, the action mechanism must complete the movement with the "dead weight" of the non-working joints. This not only increases the action inertia of the overall mechanism but also greatly reduces the mechanical efficiency, which is especially detrimental to medical robots. This kind of application has high requirements on movement accuracy and energy efficiency.

Secondly, in terms of drive control (control science), the current rotation mechanism of medical robots mainly rotates in series with multiple single-degree-of-freedom joints. Each joint is connected in turn by a connecting rod frame, and the rotation centers of the three degrees of freedom are connected together. Not only that, it increases the motion space required to complete the rotation, and also complicates the inverse kinematics control calculation. The Jacobian matrix must be calculated and the offset component must be added to the rotation matrix. Under this mechanical structure, the axis of the series actuator is not fixed when performing compound motion, the path to reach the same coordinate is not unique, and the inverse kinematics solution is complicated, causing control problems. And due to the superposition of series series, each joint will introduce transmission errors. The accumulation of these errors may lead to increased deviations in the position and attitude of the end effector, reducing execution accuracy.

Finally, in terms of rotational form (kinematics), traditional artificial power hip joints are mainly based on series transmission. Rotational motion around three axes is achieved through simple superposition of single-axis drives, but only with mechanical compromises to achieve space. The motion effect of the three rotational degrees of freedom within the actuator is not spherical, and it fails to simulate the motion effect of the ball-like hinge of the human hip joint in bionics. Moreover, the series robot arm has high requirements on the mechanical properties of each rod, and the load-bearing performance is affected by the strength and stiffness of each robot arm. The total load capacity of a tandem manipulator may be limited due to limitations of the drives and gearing at each joint. Larger loads may cause unbalanced joint torques and even exceed the load-bearing capacity of the system.

Contents of the invention

The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present invention is to propose a three-degree-of-freedom joint driver with multi-drive hierarchical output and spherical center rotation, which can achieve high energy density and high mechanical efficiency in a compact shape, a spherical actuator motion trajectory, and no mechanical The structurally compromised three-degree-of-freedom rotational motion enables the key performance indicators of the artificial joint actuator to be close to those of the human hip joint as a whole, and the manufacturing cost is low.

The multi-drive hierarchical output and three-degree-of-freedom joint driver of the ball center rotation of the present invention includes:

The motor part includes a left motor, a middle motor and a right motor arranged side by side in the same direction;

Gear part, the gear part includes a differential bevel gear assembly and a spherical gear assembly, the differential bevel gear assembly is connected to the left motor and the right motor, and the spherical gear assembly is connected to the intermediate motor;

An output shaft, one end of which is coupled with the differential bevel gear assembly and the spherical gear assembly;

The input power of the left motor and the right motor is transmitted to the output shaft through the differential bevel gear assembly, and the input power of the intermediate motor is transmitted to the output shaft through the spherical gear assembly, thereby achieving classification. Power output, and the motion trajectory surface of the output shaft is a spherical surface.

When the three-degree-of-freedom joint driver with multi-drive hierarchical output and spherical center rotation in the embodiment of the present invention is used, the left motor, right motor and middle motor in the motor part control the differential bevel gear assembly and the spherical gear assembly in the gear module. To control the movement of the output shaft, the output shaft will make a spherical motion centered on a fixed point, imitating the movement characteristics of the greater trochanter of the femur in the acetabulum, and achieving a spherical hinge-like constraint effect.

To sum up, the three-degree-of-freedom joint actuator with multi-drive hierarchical output and spherical center rotation according to the embodiment of the present invention can achieve high energy density and high mechanical efficiency in a compact shape, a spherical actuator motion trajectory, and no mechanical structure compromise. The three-degree-of-freedom rotational motion makes the key performance indicators of the three-degree-of-freedom joint actuator with multi-drive hierarchical output and ball center rotation close to that of the human hip joint as a whole, and the manufacturing cost is low.

In some embodiments, different load degrees of freedom are used to output power in stages, and the motion state of the output shaft is controlled by a combination of the left motor, the middle motor, and the right motor, wherein the low load degree of freedom is only controlled by the left motor, the middle motor, and the right motor. The middle motor is driven, the medium load degree of freedom is driven by the left motor and the right motor, and the high load degree of freedom is driven by the left motor, the right motor and the middle motor.

In some embodiments, the rotational state of the output shaft is controlled by the rotational speed coupling of the left motor, the right motor and the middle motor; if the rotation directions of the left motor and the right motor are opposite, and the When the middle motor rotates in the same direction as the left motor or the right motor, the output shaft rotates around the axis of the middle motor. At this time, the left motor, the right motor and the middle motor Work simultaneously and output the maximum load power; when the intermediate motor does not rotate, if the left motor and the right motor rotate in the same direction, the output shaft rotates around the axis of the differential bevel gear assembly, so The axis of the differential bevel gear assembly is perpendicular to the axes of the left motor, the right motor and the middle motor. At this time, the left motor and the right motor work and output intermediate load power; when the left motor The motor and the right motor do not rotate. When the middle motor rotates, the output shaft rotates. The rotation direction of the output shaft is the same as that of the middle motor. At this time, only the middle motor works and the output is low. Load power.

In some embodiments, the intersection points of the rotation axes of the three degrees of freedom of the output shaft coincide with a fixed point in space, and the output shaft performs a spherical rotation in space with the fixed point as the center of the sphere.

In some embodiments, the motor part further includes a mounting frame on which the left motor, the middle motor and the right motor are mounted.

In some embodiments, the differential bevel gear assembly includes a left motor bevel gear, a left bidirectional bevel gear, a differential output bevel gear, a right motor bevel gear, a right bidirectional bevel gear, and a C-shaped coupling plate; the left motor bevel gear The gear is fixed on the output shaft of the left motor; the left bidirectional bevel gear meshes with the left motor bevel gear; the right motor bevel gear is fixed on the output shaft of the right motor; the right bidirectional bevel gear mesh with the right motor bevel gear; the differential output gear meshes with the left bidirectional bevel gear and the right bidirectional bevel gear respectively; the C-shaped coupling plate meshes with the differential output bevel gear and the One end of the output shaft is fixed.

In some embodiments, the differential bevel gear assembly further includes a left main shaft, a right main shaft and a bevel gear fastening stopper, the left main shaft and the right main shaft are coaxially disposed and connected with the left main shaft. The output shaft of the motor, the output shaft of the middle motor and the output shaft of the right motor are vertical; the left bidirectional bevel gear is fixed on the left main shaft, and the left end of the left main shaft and the left bidirectional bevel gear The gears are rotatably supported on the mounting frame respectively; the right two-way bevel gear is fixed on the right main shaft, and the right end of the right main shaft and the right two-way bevel gear are rotatably supported on the mounting frame respectively on; the bevel gear fastening limiter is fixedly installed on the left main shaft and the right main shaft to limit the differential output bevel gear; the C-shaped coupling plate is installed on the bevel gear The gear fastening stopper is rotatable relative to the bevel gear fastening stopper.

In some embodiments, the mounting bracket includes a left mounting ear, a left support plate, a right mounting ear, and a right support plate; the left end of the left spindle is rotatably mounted on the left mounting ear, and the left two-way cone The gear is rotatably supported on the concave arc top of the left support plate; the right end of the right spindle is rotatably installed on the right mounting lug, and the right two-way bevel gear is rotatably supported on the right support plate. On the top of the concave arc.

In some embodiments, the differential bevel gear assembly further includes a left lubrication sleeve and a right lubrication sleeve; the left lubrication sleeve is sleeved on the left two-way bevel gear and located on the left support plate and the left two-way bevel gear. between the gears; the right lubricating sleeve is sleeved on the right two-way bevel gear and is located between the right support plate and the right two-way bevel gear.

In some embodiments, the spherical gear assembly includes a fixed-end spherical gear coupling, a fixed-end spherical gear, an output-end spherical gear coupling, an output-end spherical gear, and a spherical gear center connecting plate; wherein, the fixed-end The spherical gear coupling is coaxially connected to the output shaft of the intermediate motor; the fixed end spherical gear is arranged in the fixed end spherical gear coupling; the output end spherical gear coupling is connected to the output shaft One end of the spherical gear is coaxially connected; the output end spherical gear is arranged in the output end spherical gear coupling and meshes with the fixed end spherical gear; there are two said spherical gear center connecting plates, two of the spherical surfaces Both ends of the gear center connecting plate are respectively hinged with the fixed end spherical gear coupling and both sides of the fixed end spherical gear coupling.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

Figure 1 is a schematic diagram of the overall structure of a three-degree-of-freedom joint driver with multi-drive hierarchical output and ball center rotation according to one embodiment of the present invention;

Figure 2 is a detailed exploded view of a three-degree-of-freedom joint actuator with multi-drive hierarchical output and ball center rotation according to one embodiment of the present invention;

Figure 3 is a schematic structural diagram of a spherical gear assembly of a three-degree-of-freedom joint driver with multi-drive hierarchical output and spherical center rotation according to an embodiment of the present invention.

Reference signs: three-degree-of-freedom joint driver 1000 with multi-drive hierarchical output and ball center rotation; motor part 1; left motor 101; middle motor 102; right motor 103; mounting bracket 104; left mounting ear 10401; left support plate 10402; Right mounting ear 10403; right support plate 10404; gear part 2; differential bevel gear assembly 201; left motor bevel gear 20101; left bidirectional bevel gear 20102; differential output bevel gear 20103; right motor bevel gear 20104; right bidirectional bevel gear 20105; C-shaped coupling plate 20106; left spindle 20107; right spindle 20108; bevel gear fastening limiter 20109; left lubrication sleeve 20110; right lubrication sleeve 20111; spherical gear assembly 202; fixed end spherical gear coupling 20201 ; Fixed end spherical gear 20202; output end spherical gear coupling 20203; output end spherical gear 20204; spherical gear center connecting plate 20205; output shaft 3.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and cannot be understood as limiting the present invention.

Referring to Figures 1 to 3, the present invention proposes a three-degree-of-freedom joint driver 1000 with multi-drive hierarchical output and ball center rotation.

Referring to FIGS. 1 to 3 , the three-degree-of-freedom joint driver 1000 with multi-drive staged output and spherical center rotation according to the embodiment of the present invention includes: a motor part 1 , a gear part 2 and an output shaft 3 . The functions of the motor part 1 and the gear part 2 are similar to the human acetabulum and femur respectively. The motor part 1 includes a left motor 101, a middle motor 102 and a right motor 103 arranged side by side in the same direction. The gear part 2 includes a differential bevel gear assembly 201 and a spherical gear assembly 202. The differential bevel gear assembly 201 is connected to the left motor 101 and the right motor 103, and the spherical gear assembly 202 is connected to the middle motor 102. One end of the output shaft 3 is coupled with the differential bevel gear assembly 201 and the spherical gear assembly 202 . The input power of the left motor 101 and the right motor 103 is transmitted to the output shaft 3 through the differential bevel gear assembly 201, and the input power of the middle motor 102 is transmitted to the output shaft 3 through the spherical gear assembly 202, thereby achieving graded power output, and the output shaft 3 The motion trajectory surface is a sphere.

Specifically, the motor part 1 is a fixed part of the entire driver, imitating the acetabular structure of the human body. The motor part 1 includes a left motor 101, a middle motor 102 and a right motor 103 arranged side by side in the same direction. The left motor 101, the middle motor 102 and the right motor 103 are three identical DC brushless reduction motors. The three motors are coupled with power-staged drives to achieve the driving effect of high torque motors without the need for traditional multi-degree-of-freedom joint drives. Each rotational degree of freedom is equipped with a high-load and high-torque motor, which saves manufacturing costs.

Gear part 2 is the movable part of the entire drive, imitating the femoral structure of the human body. The gear part 2 includes a differential bevel gear assembly 201 and a spherical gear assembly 202. The differential bevel gear assembly 201 is connected to the left motor 101 and the right motor 103, and the spherical gear assembly 202 is connected to the middle motor 102. In this way, the power motion input by the left motor 1 and the right motor 103 can be transmitted through the differential bevel gear assembly 201, and the power motion input by the middle motor 102 can be transmitted through the spherical gear assembly 202. Through the differential bevel gear assembly 201 and the spherical gear Component 202 performs dual coupling. One end of the output shaft 3 is coupled with the differential bevel gear assembly 201 and the spherical gear assembly 202 . The power motion input by the left motor 101 and the right motor 103 is transmitted to the output shaft 3 through the differential bevel gear assembly 201, and the power motion input by the middle motor 102 is transmitted to the output shaft 3 through the spherical gear assembly 202. Since the differential bevel gear assembly 201 and The spherical gear assemblies 202 are coupled to one end of the output shaft 3, so that the output shaft 3 can rotate without obstruction within a certain range in three rotation directions, thereby realizing the output of power at different angles. By controlling the left motor 101, the right motor 103 and the middle motor 102, under the coupling effect of the differential bevel gear assembly 201 and the spherical gear assembly 202, a graded power output is achieved, for example, different load degrees of freedom are used to grade the output power, and the output shaft 3 The motion state is controlled by the combination of the left motor 101, the middle motor 102 and the right motor 103. The low load degree of freedom (internal rotation and external rotation) is only driven by the middle motor 103, and the medium load degree of freedom (adduction and abduction) is driven by the left motor 101 and the right motor 103. Driven by the motor 103, the high load degree of freedom (flexion and extension) is jointly driven by the left motor 101, the right motor 102 and the middle motor 103. This greatly simplifies the motion algorithm design and mechanical structure design, and also provides convenience for exploring more application scenarios. Since the spherical gear assembly 202 is used and the spherical gear assembly 202 is connected to one end of the output shaft 3, it is ensured that the motion trajectory surface of the output shaft 3 is a spherical surface, that is, the output shaft 3 will perform a spherical motion centered on a fixed point, imitating the femur. The movement characteristics of the greater trochanter in the acetabulum achieve a ball-joint-like restraint effect.

In terms of dynamic characteristics of the three-degree-of-freedom joint actuator 1000 with multi-drive hierarchical output and spherical center rotation according to the embodiment of the present invention, three motors with the same parameters are placed side by side That is, the left motor 101, the middle motor 102, and the right motor 103 are driven by 3, 2, and 1 motors respectively during different load degrees of freedom such as flexion and extension, adduction and abduction, internal rotation, and external rotation. This power arrangement completely simulates The driving mechanism of the human hip joint can increase the reuse rate of motors, reduce the power requirements of a single motor, and reduce the overall size of the driver. The multi-drive hierarchical coupling output principle of the three-degree-of-freedom joint driver 1000 with multi-drive hierarchical output and ball center rotation imitates the human body's multiple muscles and uses time-sharing coupled drives to achieve hierarchical output with different load degrees of freedom to improve the performance of each drive unit. utilization, and improve overall energy density and mechanical efficiency.

In terms of control characteristics of the three-degree-of-freedom joint actuator 1000 with multi-drive hierarchical output and spherical center rotation according to the embodiment of the present invention, the three motors of the three-degree-of-freedom joint actuator 1000 with multi-drive hierarchical output and spherical center rotation pass through a differential bevel gear assembly. 201 and the spherical gear assembly 202 engage in multi-stage meshing to drive the output shaft 3 to move. It can perform three-degree-of-freedom rotation in space without using cascade hinges, significantly reducing the work space required to complete three-degree-of-freedom rotation, and eliminating the need for mechanical Simplified joint driver control algorithm. The spherical motion centered on a fixed point makes any point in the space have unique coordinates. The hierarchical coupling control of the motor part 1 to the output shaft 3 makes the arrival path of any point in the space have a unique solution, which reduces the difficulty of solving inverse kinematics. The design of the spherical trajectory enables precise workspace control. By controlling the angle and motion trajectory of each joint, precise position and attitude control can be achieved.

In terms of kinematic characteristics of the three-degree-of-freedom joint actuator 1000 with multi-drive hierarchical output and ball center rotation according to the embodiment of the present invention, the three-degree-of-freedom joint actuator 1000 with multi-drive hierarchical output and ball center rotation separates the rotation center of the three rotational degrees of freedom. Placed at the same center of the sphere, rather than a series connection of multiple single-degree-of-freedom joints. Through the meshing of the differential bevel gear assembly 201 and the spherical gear assembly 202, the three-degree-of-freedom joint driver 1000 with multi-drive staged output and spherical center rotation can realize the transmission of power at different angles, so that the intersection points of the rotation axes coincide with one point in space. It imitates the motion characteristics of the greater trochanter of the femur in the acetabulum to achieve a ball-joint-like restraint effect. This structure eliminates the length of the rod in the conventional multi-rod hinge joint structure, so that only the motor needs to be controlled to drive the rotating ball head to complete the three-degree-of-freedom rotation of the end effector, which greatly reduces the overall dimensions of the joint driver. It also simplifies the control of the joint driver from the core design level of the rotating mechanism, achieving a wide range of rotation without structural compromise. Because it is similar to the movement trajectory of the human hip joint, it can achieve a more natural gait when applied to prostheses, exoskeletons, and humanoid robots. Under the dual coupling of the differential bevel gear assembly 201 and the spherical gear assembly 202, the three-degree-of-freedom joint driver 1000 with multi-drive graded output and spherical center rotation can achieve obstacle-free rotation of 0-120 degrees in three rotation directions, which is extremely The greatly simplified motion algorithm design and mechanical structure design also provide convenience for exploring more application scenarios.

In terms of manufacturing cost, the three-degree-of-freedom joint actuator 1000 with multi-drive hierarchical output and ball center rotation according to the embodiment of the present invention is driven by three motors coupled with power in stages. Three small-torque motors can be used to achieve the driving effect of a large-torque motor, without the need to configure a high-load, high-torque motor for each rotational degree of freedom like a traditional multi-degree-of-freedom joint driver. This saves manufacturing costs and adds value to existing joints. The drive design provides a lower cost, better performance drive form option.

In summary, the three-degree-of-freedom joint actuator 1000 with multi-drive hierarchical output and spherical center rotation according to the embodiment of the present invention can achieve high energy density and high mechanical efficiency in a compact shape, a spherical actuator motion trajectory, and no mechanical structural compromise. The three-degree-of-freedom rotary motion makes the key performance indicators of the three-degree-of-freedom joint actuator 1000 with multi-drive hierarchical output and ball center rotation close to that of the human hip joint as a whole, and the manufacturing cost is low.

In some embodiments, different load degrees of freedom are used to output power in stages, and the motion state of the output shaft 3 is controlled by a combination of the left motor 101, the middle motor 102, and the right motor 103. The low load degrees of freedom are only driven by the middle motor 102. The medium load degree of freedom is driven by the left motor 101 and the right motor 103, and the high load degree of freedom is driven by the left motor 101, the right motor 103 and the middle motor 102.

Specifically, when low load degree of freedom is used to output power, the left motor 101 and the right motor 103 do not rotate, only the middle motor 102 rotates, and the output shaft 3 maintains the same rotation direction and rotation speed as the middle motor 102, thereby simulating the hip joint. Internal and external rotation movements.

When the medium load degree of freedom is used to output power, the middle motor 102 does not rotate, and the left motor 101 and the right motor 103 rotate; when the left motor 101 and the right motor 103 rotate in the same direction, the output shaft 3 will be together with the C-shaped coupling plate 20106 , rotates with the bevel gear fastening limiter 20109 as the axis; when the rotation directions of the left motor 101 and the right motor 103 are different, the output shaft 3 and the C-shaped coupling plate 20106 rotate with the coaxially arranged left main shaft 20107 and The right spindle 20108 serves as the axis for rotation, thereby simulating the adduction and abduction motion of the hip joint.

When high load freedom is used to output power, the left motor 101, the right motor 103 and the middle motor 102 rotate at the same time, and the output shaft 3 will maintain the same rotation direction and speed as the middle motor 102; when the left motor 101 and the right motor 103 If the rotation directions are the same, the output shaft 3 will rotate with the C-shaped coupling plate 20106 with the bevel gear fastening stopper 20109 as the axis; when the rotation directions of the left motor 101 and the right motor 103 are different, the output shaft 3 and C Together with the shape coupling plate 20106, the coaxial left main axis 20107 and the right main axis 20108 are used as axes to rotate, thereby simulating the flexion and extension motion of the hip joint.

This power arrangement simulates the driving mechanism of the human hip joint, which can increase the reuse rate of motors, reduce the power requirements of a single motor, and reduce the overall size of the driver. The multi-drive hierarchical coupling output principle of the multi-drive hierarchical output and ball center rotating three-degree-of-freedom joint driver 1000 of the embodiment of the present invention imitates the human body's multiple muscles time-sharing multiplexed coupling drive, realizing hierarchical output with different load degrees of freedom to improve utilization of each drive unit and improve overall energy density and mechanical efficiency.

In some embodiments, the output shaft 3 realizes rotation of 0-120° in three degrees of freedom. Under the dual coupling of the differential bevel gear assembly 201 and the spherical gear assembly 202, the output shaft 3 can achieve obstacle-free rotation of 0-120° in three rotation directions, greatly simplifying the motion algorithm design and mechanical structure design, and also providing It provides convenience to explore more application scenarios.

In some embodiments, the rotation state of the output shaft 3 is controlled by the rotation speed coupling of the left motor 101, the right motor 103 and the middle motor 102; if the left motor 101 and the right motor 103 rotate in opposite directions, and the middle motor 102 and the left motor 101 rotate When the direction is the same or the rotation direction of the right motor 103 is the same, the output shaft 3 rotates around the axis of the middle motor 102. At this time, the left motor 101, the right motor 103 and the middle motor 102 work at the same time and output the maximum load power; when the middle motor 102 does not When rotating, if the left motor 101 and the right motor 103 rotate in the same direction, the output shaft 3 rotates around the axis of the differential bevel gear assembly 201, and the axis of the differential bevel gear assembly 201 is connected to the left motor 101, the right motor 103 and the middle motor 102. The axes are all vertical, that is, the axis of the differential bevel gear assembly 201 can be understood as the same axis where the left two-way bevel gear 20102 and the right two-way bevel gear 20105 in Figure 2 are located. At this time, the left motor 101 and the right motor 103 work and output the intermediate level load power; if the left motor 101 and the right motor 103 rotate in opposite directions, the output shaft 3 rotates around the axis of the middle motor 102; when the left motor 101 and the right motor 103 do not rotate and the middle motor 102 rotates, the output shaft 3 rotates and the output The rotation direction of the shaft 3 is the same as the rotation direction of the intermediate motor 102. At this time, only the intermediate motor 102 works and outputs low load power.

In some embodiments, the intersection points of the rotation axes of the three degrees of freedom of the output shaft 3 coincide with a fixed point in space, and the output shaft 3 performs a spherical rotation in space with the fixed point as the center of the sphere.

In some embodiments, the motor part 1 also includes a mounting frame 104, on which the left motor 101, the middle motor 102 and the right motor 103 are installed. The left motor 101, the middle motor 102 and the right motor 103 are installed through the mounting frame 104. Fixed support.

In some embodiments, the differential bevel gear assembly 201 includes a left motor bevel gear 20101, a left bidirectional bevel gear 20102, a differential output bevel gear 20103, a right motor bevel gear 20104, a right bidirectional bevel gear 20105, and a C-shaped coupling plate 20106; The left motor bevel gear 20101 is fixed on the output shaft 3 of the left motor 101; the left bidirectional bevel gear 20102 meshes with the left motor bevel gear 20101; the right motor bevel gear 20104 is fixed on the output shaft 3 of the right motor 103; the right bidirectional bevel gear 20105 It meshes with the right motor bevel gear 20104; the differential output gear meshes with the left bidirectional bevel gear 20102 and the right bidirectional bevel gear 20105 respectively; the C-shaped coupling plate 20106 is fixed with the differential output bevel gear 20103 and one end of the output shaft 3 respectively. Among them, the left two-way bevel gear 20102 and the right two-way bevel gear 20105 are designed to be connected by a pair of oppositely facing bevel gears, which are equivalent to two coaxially connected bevel gears. The left two-way bevel gear 20102 can be connected to the left motor at the same time. The bevel gear 20101 meshes with the differential output bevel gear 20103, and the right bidirectional bevel gear 20105 can mesh with the right motor bevel gear 20104 and then the differential output bevel gear 20103 at the same time.

It can be understood that the power input by the left motor 101 is transmitted to the differential output bevel gear 20103 through the left motor bevel gear 20101 and the left bidirectional bevel gear 20102, and the power input by the right motor 103 is transmitted through the right motor bevel gear 20104 and the right bidirectional bevel gear 20105. It is transmitted to the differential output bevel gear 20103, through which the power transmitted by the left bidirectional bevel gear 20102 and the right bidirectional bevel gear 20105 is coupled, and transmitted to the output shaft 3 through the C-shaped coupling plate 20106.

In some embodiments, the differential bevel gear assembly 201 also includes a left main shaft 20107, a right main shaft 20108, and a bevel gear fastening stopper 20109. The left main shaft 20107 and the right main shaft 20108 are coaxially disposed with the left motor 101 The output shaft 3, the output shaft 3 of the middle motor 102 and the output shaft 3 of the right motor 103 are vertical; the left two-way bevel gear 20102 is fixed on the left main shaft 20107, and the left end of the left main shaft 20107 and the left two-way bevel gear 20102 rotate respectively Supported on the mounting frame 104; the right two-way bevel gear 20105 is fixed on the right main shaft 20108, and the right end of the right main shaft 20108 and the right two-way bevel gear 20105 are respectively rotatably supported on the mounting frame 104; the bevel gear fastening limiter 20109 Fixedly installed on the left spindle 20107 and the right spindle 20108 to limit the differential output bevel gear 20103; the C-shaped coupling plate 20106 is installed on the bevel gear fastening limiter 20109 and is fixed relative to the bevel gear. The device 20109 can be rotated.

It can be understood that the differential output bevel gear 8 meshes with the left bidirectional bevel gear 20102 and the right bidirectional bevel gear 20105 at the same time, and can rotate around the left main shaft 20107 and the right main shaft 20108, or can rotate around the main shaft of the intermediate motor 102. The bevel gear fastening limiter 20109 is fixedly installed on the left main shaft 20107 and the right main shaft 20108 to limit the displacement of the differential output bevel gear 20103. The C-shaped coupling version 20106 can be tightly connected with the differential output bevel gear 20103 through bolts and installed on the bevel gear fastening stopper 20109. Its movement is the same as the differential output bevel gear 20103 and can be rotated around the left main shaft 20107 and the right main shaft 20107. The side spindle 20108 rotates and can also rotate around the main spindle of the middle motor 102. The C-shaped coupling plate 20106 is directly connected to the output shaft 3 at the same time, so that the output shaft 3 can rotate around the left main shaft 20107 and the right main shaft 20108, and can also rotate around the main shaft of the middle motor 102.

In some embodiments, the mounting bracket 104 includes a left mounting ear 10401, a left support plate 10402, a right mounting ear 10403, and a right support plate 10404; the left end of the left spindle 20107 is rotatably mounted on the left mounting ear 10401, and the left bidirectional bevel gear 20102 is rotatably supported on the top of the concave arc of the left support plate 10402; the right end of the right spindle 20108 is rotatably mounted on the right mounting lug 10403, and the right two-way bevel gear 20105 is rotatably supported on the top of the concave arc of the right support plate 10404. The structural layout is reasonable and reliable.

In some embodiments, the differential bevel gear assembly 201 also includes a left lubrication sleeve 20110 and a right lubrication sleeve 20111; the left lubrication sleeve 20110 is sleeved on the left bidirectional bevel gear 20102 and is located between the left support plate 10402 and the left bidirectional bevel gear 20102. between; the right lubrication sleeve 20111 is set on the right two-way bevel gear 20105 and is located between the right support plate 10404 and the right two-way bevel gear 20105. It can be understood that the left lubricating sleeve 20110 is set on the left two-way bevel gear 20102, which can play a buffering and lubricating role to facilitate the rotation of the left two-way bevel gear 20102; the right lubricating sleeve 20111 is set on the right two-way bevel gear 20105, which can It plays the role of buffering and lubrication to facilitate the rotation of the right two-way bevel gear 20105.

In some embodiments, the spherical gear assembly 202 includes a fixed-end spherical gear coupling 20201, a fixed-end spherical gear 20202, an output-end spherical gear coupling 20203, an output-end spherical gear 20204, and a spherical gear center connecting plate 20205; wherein, The fixed end spherical gear coupling 20201 is coaxially connected to the output shaft 3 of the intermediate motor 102; the fixed end spherical gear 20202 is set in the fixed end spherical gear coupling 20201; the output end spherical gear coupling 20203 is connected to the output shaft 3 One end is coaxially connected; the output end spherical gear 20204 is set in the output end spherical gear coupling 20203 and meshes with the fixed end spherical gear 20202; there are two spherical gear center connecting plates 20205, and the two spherical gear center connecting plates 20205 are at both ends It is hinged with both sides of the fixed end spherical gear coupling 20201 and the fixed end spherical gear coupling 20201 respectively.

It can be understood that a pair of unrestricted intermeshing spherical gears can perform rotational motion in space with three degrees of freedom. Under the constraints of the spherical gear center connecting plate 20205, the fixed-end spherical gear coupling 20201 and the output-end spherical gear coupling 20203, the output-end spherical gear 20204 loses one degree of freedom, and the output-end spherical gear 20204 can rotate around the fixed-end spherical gear 20202 moves with two degrees of freedom: one is to move with the C-shaped coupling plate 20106 and rotate with the connection hole on the fixed-end spherical gear coupling 20201 as the axis; the other is to follow the fixed-end spherical gear coupling 20201 to rotate around Its self-axis rotation is based on the self-axis rotation of the output end spherical gear 20204. Among them, the spherical gear center connecting plate 20205 ensures that the distance between the center of the fixed-end spherical gear 20202 and the center of the output-end spherical gear 20204 remains unchanged, ensuring that the motion trajectory surface of the output shaft 3 is a spherical surface, that is, the output shaft 3 can move The spherical motion centered on a fixed point imitates the motion characteristics of the greater trochanter of the femur in the acetabulum, achieving a ball-like hinge restraint effect.

In the description of this specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" or the like is intended to be incorporated into the description of the implementation. An example or example describes a specific feature, structure, or characteristic that is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art will appreciate that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and purposes of the invention. The scope of the invention is defined by the claims and their equivalents.

Claims (10)

1. A three degree of freedom joint driver for multi-drive staged output and center of sphere rotation, comprising:

the motor part comprises a left motor, a middle motor and a right motor which are arranged side by side in the same direction;

the gear part comprises a differential bevel gear assembly and a spherical gear assembly, the differential bevel gear assembly is connected with the left motor and the right motor, and the spherical gear assembly is connected with the middle motor;

one end of the output shaft is coupled with the differential bevel gear assembly and the spherical gear assembly;

the input power of the left motor and the right motor is transmitted to the output shaft through the differential bevel gear assembly, the input power of the middle motor is transmitted to the output shaft through the spherical gear assembly, so that graded power output is realized, and the movement track surface of the output shaft is spherical.

2. The three degree of freedom joint driver of multi-drive staged output and ball center rotation according to claim 1, wherein staged output power of different load degrees of freedom is adopted, the motion state of the output shaft is controlled by the combination among the left motor, the middle motor and the right motor, wherein the low load degree of freedom is driven by the middle motor only, the middle load degree of freedom is driven by the left motor and the right motor, and the high load degree of freedom is driven by the left motor, the right motor and the middle motor together.

3. The three degree of freedom joint driver of multi-drive hierarchical output and spherical center rotation according to claim 2, wherein the rotation state of the output shaft is controlled by the rotational speed coupling of the left motor, the right motor and the middle motor; if the rotation directions of the left motor and the right motor are opposite, and the rotation direction of the middle motor and the rotation direction of the left motor are the same or the rotation direction of the right motor are the same, the output shaft rotates around the axis of the middle motor, and at the moment, the left motor, the right motor and the middle motor work simultaneously and output the maximum-stage load power; when the middle motor does not rotate, if the rotation directions of the left motor and the right motor are the same, the output shaft rotates around the axis of the differential bevel gear assembly, the axis of the differential bevel gear assembly is perpendicular to the axes of the left motor, the right motor and the middle motor, and at the moment, the left motor and the right motor work and output middle-stage load power; when the left motor and the right motor do not rotate, the output shaft rotates when the middle motor rotates, the rotation direction of the output shaft is the same as that of the middle motor, and only the middle motor works and outputs low-load power.

4. The three degree-of-freedom joint driver for multi-drive staged output and center of sphere rotation of claim 2, wherein the intersection points of the rotational axes of the three degrees of freedom of the output shaft spatially coincide with a fixed point, and the output shaft performs spatial spherical rotation with the fixed point as the center of sphere.

5. The multi-drive, stepped output and center of sphere rotary three degree of freedom joint driver of any one of claims 1-4 wherein said motor portion further comprises a mounting frame on which said left motor, said middle motor and said right motor are mounted.

6. The three degree of freedom joint driver of multi-drive staged output and center of sphere rotation of claim 5, wherein the differential bevel gear assembly comprises a left motor bevel gear, a left bi-directional bevel gear, a differential output bevel gear, a right motor bevel gear, a right bi-directional bevel gear and a C-shaped coupling plate; the left motor bevel gear is fixed on an output shaft of the left motor; the left bidirectional bevel gear is meshed with the left motor bevel gear; the right motor bevel gear is fixed on an output shaft of the right motor; the right bidirectional bevel gear is meshed with the right motor bevel gear; the differential output gear is meshed with the left bidirectional bevel gear and the right bidirectional bevel gear respectively; the C-shaped coupling plate is fixed with one end of the differential output bevel gear and one end of the output shaft respectively.

7. The multi-drive, stepped output and center-of-sphere, three degree of freedom joint driver of claim 6, wherein said differential bevel gear assembly further comprises a left side spindle, a right side spindle and a bevel gear tightening limiter, said left side spindle and said right side spindle being coaxially disposed and perpendicular to an output shaft of said left motor, an output shaft of said intermediate motor and an output shaft of said right motor; the left bidirectional bevel gear is fixed on the left main shaft, and the left end of the left main shaft and the left bidirectional bevel gear are respectively and rotatably supported on the mounting frame; the right bidirectional bevel gear is fixed on the right main shaft, and the right end of the right main shaft and the right bidirectional bevel gear are respectively and rotatably supported on the mounting frame; the bevel gear fastening limiter is fixedly arranged on the left main shaft and the right main shaft so as to limit the differential output bevel gear; the C-shaped coupling plate is mounted on and rotatable relative to the bevel gear tightening limiter.

8. The multi-drive, stepped output and center-of-sphere, three degree of freedom joint driver of claim 7, wherein said mounting bracket comprises a left mounting ear, a left support plate, a right mounting ear and a right support plate; the left end of the left main shaft is rotatably mounted on the left mounting lug, and the left bidirectional bevel gear is rotatably supported on the concave arc top end of the left supporting plate; the right end of the right main shaft is rotatably mounted on the right mounting lug, and the right bidirectional bevel gear is rotatably supported on the concave arc top end of the right supporting plate.

9. The multi-drive, stepped output and center-of-sphere, three degree of freedom joint driver of claim 8, wherein said differential bevel gear assembly further comprises a left wetting sleeve and a right wetting sleeve; the left lubrication sleeve is sleeved on the left bidirectional bevel gear and is positioned between the left support plate and the left bidirectional bevel gear; the right lubrication sleeve is sleeved on the right bidirectional bevel gear and is positioned between the right support plate and the right bidirectional bevel gear.

10. The three degree of freedom joint driver of any one of claims 1-4 wherein the spherical gear assembly includes a fixed end spherical gear coupling, a fixed end spherical gear, an output end spherical gear coupling, an output end spherical gear and a spherical gear center connection plate; the fixed end spherical gear coupler is coaxially connected with an output shaft of the intermediate motor; the fixed end spherical gear is arranged in the fixed end spherical gear coupler; the output end spherical gear coupler is coaxially connected with one end of the output shaft; the output end spherical gear is arranged in the output end spherical gear coupler and meshed with the fixed end spherical gear; the two ends of the spherical gear center connecting plates are respectively hinged with the fixed end spherical gear coupler and the two sides of the fixed end spherical gear coupler.