Patent Description:
With the continuous development of science and technology, robot arms are not only used to replace monotonous, repetitive, and dangerous work in manufacturing to improve the automation degree and reduce the labor cost, but also used to achieve a human-machine cooperation with operators to complete some special works with higher difficulty, complexity, and accuracy. Therefore, the performance and reliability of the joint module of the robot arm, such as a driving assembly, a speed reduction assembly, and other components, are particularly important. However, in related arts (such as <CIT>), a rotor of the driving assembly is fixed on an input shaft of the speed reduction assembly, that is, the driving assembly does not have an independent output shaft. So that it is difficult to independently carry out a performance test to the driving assembly, accordingly, the reliability of the driving assembly can hardly be ensured. As a result, the performance test for the driving assembly can only be carried out after the driving assembly is assembled with the speed reduction assembly and a housing. If the driving assembly does not pass the performance test, it needs to remove the driving assembly from the speed reduction assembly. Therefore, there may exist the defects of needing to assemble and disassemble the driving assembly repeatedly, and resulting a damage to the driving assembly during assembly and disassembly, which greatly reduces the production efficiency and increases the production cost.

<CIT> discloses an integrated robot joint module. The integrated robot joint module includes a joint output component, a harmonic reducer, a joint shell, a driving motor main body, a brake mechanism and an integrated circuit module; the joint output component is used for being connected with an external execution mechanism or a load; the harmonic reducer is used for adjusting the rotating speed of the joint output component; the joint shell is used for fixing the harmonic reducer and driving the motor main body, the brake mechanism and the integrated circuit module, and the driving motor main body is used for driving the harmonic reducer according to the instruction of the integrated circuit module; the brake mechanism is used for holding the driving motor main body according to an instruction of the integrated circuit module; and the integrated circuit module drives the working state of the motor main body according to an instruction of an external upper computer, and the working state of the joint output component is used for driving the driving motor main body.

<CIT> discloses a robot equipped with two joint parts attached to an end of an arm in a coupled state. For example, in a joint part of a robot, a motor and a reduction gear are housed in a case, and an output-side member having a flange is fixed to the output shaft of the reduction gear. An opening that opens in the direction orthogonal to the axial direction of the output shaft of the reduction gear is formed in the case. A planar attachment face orthogonal to the opening direction of the opening is formed in the opening. The robot is provided with a plurality of biaxial joint units comprising two joint parts. In the robot, the attachment face of the case of one joint part constituting a biaxial joint unit is fixed to the flange of the other joint part either directly or via a coupling member.

<CIT> discloses an actuator including: a motor; a brake; a motor casing that accommodates a constituent member of the motor; and a brake casing that accommodates a constituent member of the brake. The motor casing and the brake casing are connected to each other, the brake includes a stator having a coil and a coil case, and a friction plate, a minimum outer diameter of the coil case is <NUM> or less, and a value obtained by dividing a distance from a first end surface of the friction plate on a side farthest in an axial direction from the coil case to a second end surface of the coil case on a side opposite to the first end surface by the minimum outer diameter is <NUM> or less.

<CIT> discloses an actuator. In the actuator in which an angle detector of a magnetic encoder for detecting the rotational position of a motor is incorporated inside a wave reduction gear, detection signals from Hall elements of the angle detector are transmitted via sensor lead wires that have been brought out through wiring holes formed inside the motor to a sensor signal converter board disposed on the rear end side of the motor.

<CIT> discloses a robot, including a motor that is driven by actuation of each joint actuator. Each actuator includes wiring module with input connector comprising power input terminals connected to preceding actuator, and output connector comprising power output terminals connected to succeeding actuator. The predetermined supply lines of supply line array section are connected with power output terminals of succeeding actuator. The remaining supply lines of supply line array section are connected with output connector of succeeding actuator.

<CIT> discloses a joint structure, including a motor component, a speed reducer, a torque sensor, and a drive circuit board component. A motor housing serves as a fixing end. The drive circuit board component controls the motor component to operate. A motor shaft of the motor component outputs the power to the speed reducer for enabling an output member to output the rotation. The torque sensor is provided between the motor housing and the speed reducer. The torque received by the output member acts on the torque sensor by means of the speed reducer. A measured torque of the torque sensor is a torque received by the output member. During measurement, there is no need to consider the intermediate transmission link, and the torque is more accurate, reliable, and effective, thereby ensuring the rigidity and stability of a system. The joint structure relates to the technical field of humanoid service robots, and has characteristics of strong universality, high integration, and modular structural design. By applying the joint structure in a robot, the torque feedback at joints is achieved, and a more accurate force control effect can be achieved, thereby ensuring the rigidity and stability of a system.

<CIT> discloses a super small-damping harmonic reducer. The spaces of two oil sealing parts are eliminated in the super small-damping harmonic reducer. The super small-damping harmonic reducer is more compact in structure and lighter in weight, so that the super small-damping harmonic reducer operates with super small damping when operating under the same conditions, and therefore, the efficiency is improved, the output load of the reducer is improved, and the service life is prolonged. The reducer comprises a central shaft, an inner ring of a cam sleeves an outer ring surface of the central shaft through a bearing, the input portion of the cam is an input end surface which is exposed outside, an outer ring of the cam is connected to an inner ring of a flexible wheel, and an outer ring of the flexible wheel is in engaged connection to an inner ring of a rigid wheel. The reducer is characterized in that two end surfaces of the rigid wheel are firmly connected to one end surface of the inner ring of the bearing and the inner end surface of the outer ring portion of the end cover, separately, the inner ring portion of the end cover is firmly connected to the corresponding position of the central shaft, a first hermetic deep groove ball bearing sleeves the outer ring surface of the cam, close to the input end surface, and an outer ring of the first hermetic deep groove ball bearing clings to the inner ring surface of the end cover of the bearing.

<CIT> discloses an electric motor, including an electromagnetically operated brake, and has housing, a rotor, and a stator. The rotor has a shaft, a rotor bundle of laminations and a rotor cast part implemented as a runner cage. The shaft is supported in the housing by a fixed bearing and a floating bearing. The tubular brake housing part consists of a flexible material, particularly rubber or a silicone. The surface carrier has two metal disks, particularly made of aluminum, which are separately connected, by an absorption material.

An embodiment of the present disclosure provides a joint module of a robot arm, the joint module includes: a housing, a driving assembly, a speed reduction assembly, a first fastener, a second fastener, and a fourth fastener. The driving assembly includes a lower bearing seat and a lower bearing, an outer ring of the lower bearing is connected with the lower bearing seat. The first fastener is configured to fix the lower bearing seat on the housing. The second fastener is configured to fix the speed reduction assembly on the housing. The speed reduction assembly includes an input shaft, a wave generator connected with the input shaft, a flexible wheel sleeved on the wave generator, a rigid wheel sleeved on the flexible wheel, and an outer bearing. The flexible wheel includes a cylindrical engaging portion and an annular bending portion obliquely connected with the cylindrical engaging portion, the annular bending portion extends to an outside of the cylindrical engaging portion, the cylindrical engaging portion is partially engaged with the rigid wheel. The fourth fastener is configured to fix the annular bending portion on an outer ring of the outer bearing, a part of the fourth fastener protrudes from the annular bending portion being arranged in an avoiding hole of the lower bearing seat. The rigid wheel is connected with an inner ring of the outer bearing.

Another embodiment of the present disclosure provides a robot arm which includes the above mentioned joint module.

In the joint module provided in the present disclosure, the output shaft of the driving assembly and the input shaft of the speed reduction assembly are separate structural members, and the two are detachably connected by fasteners, which not only allows the driving assembly and the speed reduction assembly to be tested separately before assembly, but also facilitates the later maintenance, and further helps to reduce the vibration and noise of the speed reduction assembly.

In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions, the accompanying drawings will be briefly described below. Obviously, the drawings are only some embodiments of the present disclosure, for those skilled in the arts, other drawings may be obtained according to the drawings without any creative work.

The technical solutions of the embodiments of the present disclosure will be clearly and completely described in the following with reference to the accompanying drawings. It is obviously that the embodiments to be described are only a part rather than all of the embodiments of the present disclosure. All other embodiments obtained by persons skilled in the art based on the embodiments of the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.

The "embodiments" in the present disclosure means that specific features, structures, or characteristics described in the embodiments may be included in at least one embodiment of the present disclosure. Persons skilled in the art may explicitly and implicitly understand that the embodiments described in the present disclosure is capable of being combined with other embodiments.

Referring to <FIG>, a robot arm <NUM> includes a joint module <NUM>, a connecting arm <NUM>, and a base <NUM>. The quantity of each of the joint module <NUM> and connecting arm <NUM> may be more than one, and the joint module <NUM> and connecting arm <NUM> may be directly or indirectly connected to the base <NUM> in certain sequence, allowing a tail end of the robot arm <NUM> away from the base <NUM> to have different freedom degrees and positions in a three-dimensional space to meet operation requirements in various application scenarios. The robot arm <NUM> may be an industrial robot arm. Compared with other robot arms such as a desktop robot arm for education, the tail end of the industrial robot arm is configured to grasp heavy objects and bear large loads, so it is necessary to reasonably design the joint module <NUM> and other structures.

Illustratively, in combination with <FIG>, the joint module <NUM> includes a housing <NUM>, a driving assembly <NUM>, a speed reduction assembly <NUM>, a braking assembly <NUM>, and an encoding assembly <NUM>. The housing <NUM> may also be served as a housing of the driving assembly <NUM>. That is, relevant structures of the driving assembly <NUM> may be directly installed on the housing <NUM>, and structures such as the speed reduction assembly <NUM>, the braking assembly <NUM>, and the encoding assembly <NUM> may also be directly or indirectly installed on the housing <NUM> according to a certain assembly sequence, making the structures of the joint module <NUM> be integrated, namely, "integrated joint module". In this way, it is beneficial to simplify the structure of the joint module <NUM>, and reduce the cost of the joint module <NUM>. Of course, in other embodiments such as those with a low integration requirement, the driving assembly <NUM> may also have a housing independent of the housing <NUM>, that is, the driving assembly <NUM> can be independently used after being separated from the housing <NUM>.

In some embodiments, the driving assembly <NUM> is mainly configured to drive the joint module <NUM> or the connecting arm <NUM> connected with the driving assembly <NUM> to rotate, the speed reduction assembly <NUM> is mainly configured to carry out speed matching and transmitting torque among the joint module <NUM>, the connecting arm <NUM>, and other structures, the braking assembly <NUM> is mainly configured to make the driving assembly <NUM> switch between a rotating state and a braking state, and the encoding assembly <NUM> is mainly configured to detect the rotation, including the rotating speed and angular position, of at least one of the driving assembly <NUM> and the speed reduction assembly <NUM>. The speed reduction assembly <NUM> and the braking assembly <NUM> may be arranged on the opposite sides of the driving assembly <NUM>, and the encoding assembly <NUM> may be arranged on a side of the braking assembly <NUM> away from the driving assembly <NUM>.

Illustratively, in combination with <FIG> and <FIG>, the housing <NUM> includes a first housing <NUM> and a second housing <NUM> connected with the first housing <NUM>, the first housing <NUM> and the second housing <NUM> may define a cavity structure with a certain volume. An inner side of the first housing <NUM> is provided with a first annular supporting platform <NUM>, and a region where the first annular supporting platform <NUM> is located has a thicker wall thickness compared with other regions of the first housing <NUM>, so as to increase a local structural strength of the first housing <NUM>; an outer side of the first housing <NUM> is defined with an assembly region which is configured to connect with the joint module <NUM> or the connecting arm <NUM>, an area where the assembly region located also has a thicker wall thickness compared with other areas of the first housing <NUM>, so as to increase a local structural strength of the first housing <NUM>. As a result, compared with the second housing <NUM>, the first housing <NUM> may have a higher structural strength in terms of both material and structural design. In this way, sub housings of the housing <NUM> may be designed differently according to actual needs, which is conducive to reducing the cost of the joint module <NUM>. Furthermore, the second housing <NUM> may cover the encoding assembly <NUM>, to protect internal structures of the joint module <NUM>.

Illustratively, in combination with <FIG>, the driving assembly <NUM> includes an output shaft <NUM>, a rotor <NUM> connected with the output shaft <NUM>, a stator <NUM> embedded in the first annular supporting platform <NUM>, a lower bearing seat <NUM> and an upper bearing seat <NUM> respectively connected with two opposite sides of the first annular supporting platform <NUM> in an axial direction of the output shaft <NUM>, a lower bearing <NUM> embedded in the lower bearing seat <NUM>, and an upper bearing <NUM> embedded in the upper bearing seat <NUM>; the rotor <NUM> is arranged on an inner side of the stator <NUM>. An inner ring and an outer ring of the lower bearing <NUM> are respectively connected with the output shaft <NUM> and the lower bearing seat <NUM>, and an inner ring and an outer ring of the upper bearing <NUM> are respectively connected with the output shaft <NUM> and the upper bearing seat <NUM>. That is, the lower bearing <NUM> and the upper bearing <NUM> are sleeved around the output shaft <NUM>, and are respectively arranged on both sides of the rotor <NUM> in the axial direction of the output shaft <NUM>. Furthermore, the rotor <NUM> includes a magnet, and the stator <NUM> includes a coil, such that members such as carbon brushes may be omitted, which simplifies the wiring of the driving assembly <NUM>, and reduces the cost of the driving assembly <NUM>. In order to meet speed and power output requirements of the driving assembly <NUM>, the quantity of the magnet may be more than one, and the quantity of the coil may also be more than one. Correspondingly, the speed reduction assembly <NUM> and the braking assembly <NUM> may be respectively connected with both ends of the output shaft <NUM>, and the encoding assembly <NUM> may be connected with one end of the output shaft <NUM> adjacent to the braking assembly <NUM>.

It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present disclosure are only configured to explain relative positional relationships, motions, etc. among components in a specific attitude (as shown in <FIG>). If the specific attitude changes, the directional indication will also change accordingly. For example, "lower bearing seat", "upper bearing seat", "lower bearing" and "upper bearing" as shown in <FIG> may be corresponding to "front bearing seat", "rear bearing seat", "front bearing" and "rear bearing" after the joint module in <FIG> is rotated by <NUM>°, and may also be corresponding to "left bearing seat", "right bearing seat", "left bearing" and "right bearing".

In some embodiments, one of the lower bearing seat <NUM> and the upper bearing seat <NUM> is integrated with the first housing <NUM>, and the other one of the lower bearing seat <NUM> and the upper bearing seat <NUM> is a separate structural member. The two members may be connected by at least one of the assembly methods including gluing, clamping, welding, and threaded connecting. In this way, the assembly efficiency of the driving assembly <NUM> is improved.

In some embodiments, the housing <NUM>, the lower bearing seat <NUM>, and the upper bearing seat <NUM> may be separate structural members, and they may be respectively connected with the first annular supporting platform <NUM> by at least one one of the assembly methods including gluing, clamping, welding, threaded connecting, etc. Similarly, the first housing <NUM>, the lower bearing seat <NUM>, and the upper bearing seat <NUM> may be designed differently in terms of material, structural design, and molding process, which is conducive to reduce the cost of the joint module <NUM>.

Illustratively, in combination with <FIG>, the lower bearing seat <NUM> may be a separate structural member, thus the lower bearing seat <NUM> may be fixed on the housing <NUM> by a first fastener <NUM>. Specifically, the first fastener <NUM> passes through the lower bearing seat <NUM> and connects with the first annular supporting platform <NUM>, to press the lower bearing seat <NUM> on the first annular supporting platform <NUM>. Similarly, the upper bearing seat <NUM> may also be a separate structural member, thus the upper bearing seat <NUM> may be fixed on the housing <NUM> by another fastener. The lower bearing seat <NUM> and the upper bearing seat <NUM> may be limited on different positions of the first housing <NUM> in the radial direction of the output shaft <NUM>.

In some embodiments, the output shaft <NUM> may include a lower fixing section <NUM>, an upper fixing section <NUM>, and an intermediate fixing section <NUM> between the lower fixing section <NUM> and the upper fixing section <NUM> along an axial direction of the output shaft <NUM>. An outer diameter of the intermediate fixing section <NUM> may be greater than outer diameters of the lower fixing section <NUM> and the upper fixing section <NUM>, such that the output shaft <NUM> has an outer step surface <NUM> between the intermediate fixing section <NUM> and the lower fixing section <NUM>, and an outer step surface <NUM> between the intermediate fixing section <NUM> and the upper fixing section <NUM>. The rotor <NUM> may be fixed on the intermediate fixing section <NUM>, the lower bearing <NUM> and the upper bearing <NUM> may sleeve on the lower fixing section <NUM> and the upper fixing section <NUM> respectively, the inner ring of the lower bearing <NUM> may be supported on the outer step surface <NUM>, and the inner ring of the upper bearing <NUM> may be supported on the outer step surface <NUM>. Furthermore, the driving assembly <NUM> includes a lower clamping ring <NUM> connected with the lower fixing section <NUM>. For example, the lower clamping ring <NUM> is clamped in a limiting groove of the lower fixing section <NUM>, and the lower clamping ring <NUM> and the intermediate fixing section <NUM> cooperatively clamp the inner ring of the lower bearing <NUM>. Similarly, the driving assembly <NUM> includes an upper clamping ring connected with the upper fixing section <NUM>, and the upper clamping ring and the intermediate fixing section <NUM> cooperatively clamp the inner ring of the upper bearing <NUM>.

In some embodiments, the output shaft <NUM> may have a hollow structure which may facilitate the wiring of the joint module <NUM>. An inner diameter of the lower fixing section <NUM> may be smaller than that of the intermediate fixing section <NUM>, so that an end of the lower fixing section <NUM> has enough wall thickness to assemble an input shaft of the speed reduction assembly <NUM>.

Illustratively, in combination with <FIG> and <FIG>, the lower bearing seat <NUM> includes a lower cylindrical portion <NUM>, and a lower fixing portion <NUM> obliquely connected with one end of the lower cylindrical portion <NUM>. The lower fixing portion <NUM> extends towards the outside of the lower cylindrical portion <NUM> to connect with the housing <NUM>, and the lower cylindrical portion <NUM> is sleeved on the lower bearing <NUM>. Specifically, the first fastener <NUM> passes through the lower fixing portion <NUM> and connects with the first annular supporting platform <NUM>, to press the lower bearing seat <NUM> on the first annular supporting platform <NUM>. The lower cylindrical portion <NUM> connects with the outer ring of the lower bearing <NUM>. One end of the first fastener <NUM> that is not inserted into the first annular supporting platform <NUM> may not protrude from the lower bearing seat <NUM>, that is, a side of the first fastener <NUM> that faces the speed reduction assembly <NUM> may inserted into the lower bearing seat <NUM> or be flush with an end face of the lower bearing seat <NUM>, such that it is not only convenient for subsequent assembly of the speed reduction assembly <NUM>, but also conducive to increasing the structural compactness of the joint module <NUM>.

In some embodiments, the lower bearing seat <NUM> further includes a lower flange portion <NUM> obliquely connected with the other end of the lower cylindrical portion <NUM>. The lower flange portion <NUM> and the lower fixing portion <NUM> extend in opposite directions. The outer ring of the lower bearing <NUM> may be supported on the lower flange portion <NUM>. Based on this, the driving assembly <NUM> may include a lower pressing ring <NUM> connected with the lower fixing portion <NUM>, and the lower pressing ring <NUM> and the lower flange portion <NUM> may cooperatively clamp the outer ring of the lower bearing <NUM>. The lower pressing ring <NUM> may not protrude from of the lower fixing portion <NUM>, to avoid structural interference or collision between the lower pressing ring <NUM> and structural members such as the rotor <NUM>.

In some embodiments, referring to <FIG>, the outer step surface <NUM> and the lower flange portion <NUM> may be arranged on a same side of the lower bearing <NUM> in the axial direction of the output shaft <NUM>, for example, the side of the lower bearing <NUM> facing the upper bearing <NUM>. Accordingly, the lower clamping ring <NUM> and the lower pressing ring <NUM> may be arranged on a same side of the lower bearing <NUM> in the axial direction of the output shaft <NUM>, for example, the side of the lower bearing <NUM> away from the upper bearing <NUM>. The lower bearing <NUM> may be at least partially arranged on a side of the lower fixing portion <NUM> towards the speed reduction assembly <NUM> (i.e., the other side of the lower fixing portion <NUM> away from the braking assembly <NUM>), for example, an orthographic projection of the lower bearing <NUM> to the inner side of the housing <NUM> along the radial direction of the output shaft <NUM> is partially overlapped with the first annular supporting platform <NUM>. A certain safety distance may exist between the rotor <NUM> (or the stator <NUM>) and relevant structures of the lower bearing <NUM> and the lower bearing seat <NUM> in the radial direction of the output shaft <NUM>, and the relevant structures of the lower bearing <NUM> and the lower bearing seat <NUM> may extend into a gap between the rotor <NUM> and the stator <NUM> along the axial direction of the output shaft <NUM>, so as to avoid structural interference or collision of the relevant structures. Based on this, in case the speed reduction assembly <NUM> is assembled on the side where the lower bearing seat <NUM> is arranged, the lower bearing <NUM> may be arranged outside the speed reduction assembly <NUM>. In this way, there is no need to consider the assembly of the lower bearing <NUM> extending into the speed reduction assembly <NUM>, so the selection of the speed reduction assembly <NUM> is more flexible. Furthermore, during the assembly of the driving assembly <NUM>, the lower bearing <NUM> may sleeve on the lower fixing section <NUM> of the output shaft <NUM> along the assembly direction, then the lower clamping ring <NUM> is clamped in the limiting groove of the lower fixing section <NUM>, allowing the lower clamping ring <NUM> and the intermediate fixing section <NUM> to cooperatively clamp the inner ring of the lower bearing <NUM>; then the lower bearing seat <NUM> sleeves on the lower bearing <NUM> in an direction opposite to the assembly direction, or the lower bearing <NUM> and the output shaft <NUM> as a whole are inserted into the lower cylindrical portion <NUM> of the lower bearing seat <NUM> in the assembly direction; then the lower pressing ring <NUM> is fixed on the lower fixing portion <NUM> of the lower bearing seat <NUM>, allowing the lower pressing ring <NUM> and the lower flange portion <NUM> of the lower bearing seat <NUM> to cooperatively clamp the outer ring of the lower bearing <NUM>. Obviously, no matter how the lower bearing seat <NUM> and the lower bearing <NUM> are assembled, the lower bearing <NUM> always presses on the lower clamping ring <NUM>, causing the lower clamping ring <NUM> bearing a greater pressure during the assembly, which brings a risk of structural failure to a certain extent.

In some embodiments, referring to <FIG> and <FIG>, the outer step surface <NUM> and the lower flange portion <NUM> may be respectively arranged on both sides of the lower bearing <NUM> in the axial direction of the output shaft <NUM>. Accordingly, the lower clamping ring <NUM> and the lower pressing ring <NUM> may be respectively arranged on both sides of the lower bearing <NUM> in the axial direction of the output shaft <NUM>. As such, the lower bearing <NUM> may be at least partially arranged on the side of the lower fixing portion <NUM> opposite to the upper bearing seat <NUM>, that is, the lower bearing <NUM> may be at least partially arranged outside the driving assembly <NUM>. In other words, orthographic projections of the stator <NUM> and the lower bearing <NUM> along the radial direction of the output shaft <NUM> may not overlap with each other, that is, the stator <NUM> and the lower bearing <NUM> are spaced from each other in the axial direction of the output shaft <NUM>. Based on this, in case the speed reduction assembly <NUM> is assembled on the side where the lower bearing seat <NUM> is arranged, the lower bearing <NUM> may be at least partially arranged in the speed reduction assembly <NUM>. In this way, there is no need to worry about the structural interference or collision between the relevant structures of the lower bearing <NUM> and the lower bearing seat <NUM> and the rotor <NUM> or the stator <NUM>, and the driving assembly <NUM> is more compact in the axial and radial directions of the output shaft <NUM>, so the driving assembly <NUM> can be provided with a larger rotor <NUM> or stator <NUM>. Furthermore, during the assembly of the driving assembly <NUM>, the lower bearing <NUM> is sleeved on the lower fixing section <NUM> of the output shaft <NUM> along the assembly direction, then the lower clamping ring <NUM> is clamped in the limiting groove of the lower fixing section <NUM>, allowing the lower clamping ring <NUM> and the intermediate fixing section <NUM> to cooperatively clap the inner ring of the lower bearing <NUM>; then, the lower bearing seat <NUM> sleeves on the lower bearing <NUM> along the assembly direction, or the lower bearing <NUM> and output shaft <NUM> as a whole is embedded in the lower cylindrical portion <NUM> of the lower bearing seat <NUM> along the direction opposite to the assembly direction, then the lower pressing ring <NUM> is fixed on the lower fixing portion <NUM> of the lower bearing seat <NUM>, allowing the lower pressing ring <NUM> and the lower flange portion <NUM> of the lower bearing seat <NUM> to cooperatively clamp the outer ring of the lower bearing <NUM>. Obviously, no matter how the lower bearing seat <NUM> and the lower bearing <NUM> are assembled, the lower bearing <NUM> always presses on the lower fixing section <NUM> rather than the lower clamping ring <NUM>, so that the lower clamping ring <NUM> bears no pressure during the assembly process, which is conducive to ensuring the reliability of the lower clamping ring <NUM>.

Illustratively, in combination with <FIG> and <FIG>, the upper bearing seat <NUM> includes an upper cylindrical portion <NUM> and an upper fixing portion <NUM> obliquely connected with one end of the upper cylindrical portion <NUM>. The upper fixing portion <NUM> extends to the outside of the upper cylindrical portion <NUM> to connect with the housing <NUM>, and the upper cylindrical portion <NUM> sleeves on the upper bearing <NUM>. Specifically, a fastener passes through the upper fixing portion <NUM> and connects with the first annular supporting platform <NUM>, to press the upper bearing seat <NUM> on the first annular supporting platform <NUM>. The upper cylindrical portion <NUM> is connected with the outer ring of the upper bearing <NUM>. The upper bearing <NUM> is at least partially arranged in the driving assembly <NUM>, which facilitates subsequent assembly of structural members such as the braking assembly <NUM>. Furthermore, orthographic projections of the upper bearing <NUM> and the stator <NUM> along the radial direction of the output shaft <NUM> may be partially overlapped with each other, for example, the relevant structures of the upper bearing <NUM> and the upper bearing seat <NUM> extend into the gap existed between the output shaft <NUM> and the stator <NUM> along the axial direction of the output shaft <NUM>, which may not only avoid structural interference or collision of the relevant structural members, but also help to increase the structural compactness of the joint module <NUM>.

In some embodiments, the upper bearing seat <NUM> includes an upper annular limiting portion <NUM> connected with the upper fixing portion <NUM>, and the upper annular limiting portion <NUM> is capable of limiting structural members such as the braking assembly <NUM> along the radial direction of the output shaft <NUM>, which will be described below.

Based on the above related description and in combination with <FIG>, the housing <NUM> may also served as the housing of the driving assembly <NUM>, so that performance test can be carried out after each component of the driving assembly <NUM> is assembled on the housing <NUM>. The first fastener <NUM> is configured to fix the lower bearing seat <NUM> on the housing <NUM>, and the upper bearing seat <NUM> may also be fixed on the housing <NUM> by another fastener. Based on this, the second fastener <NUM> may fix the speed reduction assembly <NUM> on the housing <NUM> and pass through the lower bearing seat <NUM>; the third fastener <NUM> may fix the input shaft <NUM> of the speed reduction assembly <NUM> on the output shaft <NUM>. In other words, the driving assembly <NUM> may be detachably connected with the housing <NUM> through the first fastener <NUM>, and the speed reduction assembly <NUM> may be detachably connected with the housing <NUM> and the driving assembly <NUM> through the second fastener <NUM> and the third fastener <NUM>, respectively, making each structural member of the joint module <NUM> be modularity. In related art, the output shaft of the driving assembly <NUM> and the input shaft of the speed reduction assembly <NUM> are integrated. For example, the rotor <NUM> of the driving assembly <NUM> is fixed on the input shaft of the speed reduction assembly <NUM>, that is, the driving assembly <NUM> does not have an independent output shaft, so it is difficult to perform performance tests on the drive assembly <NUM>. Different from related art, in the present disclosure, the output shaft <NUM> of the driving assembly <NUM> and the input shaft <NUM> of the speed reduction assembly <NUM> are separate structural members and are detachably connected by the third fastener <NUM>, so performance tests can be respectively carried out on the driving assembly <NUM> and the speed reduction assembly <NUM> before assembly, and it is also conductive to the maintain in later, as well as the reducing of the vibration and noise of the speed reduction assembly <NUM>.

Illustratively, the first fastener <NUM> passes through the lower fixing portion <NUM> and connects with the first annular supporting platform <NUM>, to press the lower bearing seat <NUM> on the first annular supporting platform <NUM>. The second fastener <NUM> passes through the speed reduction assembly <NUM> and the lower fixing portion <NUM> successively and connects with the first annular supporting platform <NUM>, to press the speed reduction assembly <NUM> and the lower bearing seat <NUM> on the first annular supporting platform <NUM>, that is, the speed reduction assembly <NUM> and the lower bearing seat <NUM> are fixed on the first annular supporting platform <NUM> by the second fastener <NUM>. Furthermore, the input shaft <NUM> has a hollow structure, which facilitates the wiring of the joint module <NUM>. The inner side of the input shaft <NUM> is provided with a second annular supporting platform <NUM>. The output shaft <NUM> is inserted into the input shaft <NUM>, and the end face of the output shaft <NUM> is resisted against the second annular supporting platform <NUM>. The third fastener <NUM> connects the second annular supporting platform <NUM> and the output shaft <NUM> along the axial direction of the output shaft <NUM>, that is, the third fastener <NUM> fixes the input shaft <NUM> on the end of the lower fixing section <NUM>. In this way, the output shaft <NUM> can be limited by the input shaft <NUM> in radial direction, and the coaxiality between the input shaft <NUM> and the output shaft <NUM> is also increased.

In some embodiments, the output shaft <NUM> extends out of the lower bearing seat <NUM>, and a mounting surface between the input shaft <NUM> and the output shaft <NUM> is arranged in the speed reduction assembly <NUM> in the axial direction of the output shaft <NUM>, so that relevant structures of the lower bearing <NUM> and the lower bearing seat <NUM> may be at least partially arranged in the speed reduction assembly <NUM>.

Illustratively, in combination with <FIG> and <FIG>, the speed reduction assembly <NUM> includes a wave generator <NUM> connected to the input shaft <NUM>, a flexible wheel <NUM> sleeved on the wave generator <NUM>, and a rigid wheel <NUM> sleeved on the flexible wheel <NUM>. The rigid wheel <NUM> is partially engaged with the flexible wheel <NUM> to facilitate achieving a corresponding transmission ratio for the speed reduction assembly <NUM>. Furthermore, the speed reduction assembly <NUM> includes a flange plate <NUM>, the flange plate <NUM> may be served as an output end of the speed reduction assembly <NUM> to connect with other joint modules <NUM> or connecting arms <NUM>.

In some embodiments, the flexible wheel <NUM> may have a cylindrical structure. Based on this, a side wall of the flexible wheel <NUM> is partially engaged with the rigid wheel <NUM>, and a bottom wall of the flexible wheel <NUM> is connected with the flange plate <NUM>. Accordingly, the rigid wheel <NUM> may be fixed on the first annular supporting platform <NUM> by the second fastener <NUM>.

In some embodiments, the flexible wheel <NUM> may be a hollow top-hat structure. Based on this, the speed reduction assembly <NUM> includes an outer bearing <NUM>, and the flexible wheel <NUM> includes a cylindrical engaging portion <NUM> and an annular bending portion <NUM> obliquely connected with one end of the cylindrical engaging portion <NUM>. The annular bending portion <NUM> extends to the outside of the cylindrical engaging portion <NUM>. The cylindrical engagement part <NUM> is partially engaged with the rigid wheel <NUM>, the annular bending portion <NUM> is connected with an outer ring of the outer bearing <NUM>, and the rigid wheel <NUM> is connected with an inner ring of the outer bearing <NUM>. And, the second fastener <NUM> fixes one of the inner ring and the outer ring of the outer bearing <NUM> on the first annular supporting platform <NUM>, and the flange plate <NUM> is connected with the other one of the inner ring and the outer ring of the outer bearing <NUM>.

Based on the above related description, and in combination with <FIG>, <FIG> and <FIG>, the relevant structures of the lower bearing <NUM> and the lower bearing seat <NUM> may be at least partially arranged in the speed reduction assembly <NUM>. For example, the lower bearing <NUM> is arranged on an inner side of the flexible wheel <NUM> opposite to the rigid wheel <NUM> in the radial direction of the output shaft <NUM>, causing the lower bearing <NUM> to occupy an internal space of the speed reduction assembly <NUM> to a certain extent. Based on this, in order to avoid structural interference or collision between the relevant structures of the lower bearing <NUM> and the lower bearing seat <NUM>, and the flexible wheel <NUM> or the input shaft <NUM>, it is easy for those skilled in the art to come up with the following technical solution: a radial size of the speed reduction assembly <NUM> is increased to increase a gap between the flexible wheel <NUM> and the input shaft <NUM> along a radial direction of the output shaft <NUM> to ensure a sufficient safety distance. The difference of the present disclosure is, in combination with <FIG>, a thickness of the lower cylindrical portion <NUM> in the radial direction of the output shaft <NUM> is smaller than a thickness of the lower flange portion <NUM> in the axial direction of the output shaft <NUM> and a thickness of the lower fixing portion <NUM> in the axial direction of the output shaft <NUM>, that is, the lower cylindrical portion <NUM> is thinned, which may not only avoid the aforementioned interference or collision, but also balance the radial size of the speed reduction assembly <NUM>. Corners of the lower cylindrical portion <NUM> and the lower fixing portion <NUM> opposite to the lower bearing <NUM> may have a circular shape to avoid a large stress concentration, thereby increasing the structural strength and reliability of the lower bearing seat <NUM>.

In some embodiments, referring to <FIG>, the speed reduction assembly <NUM> includes a hollow shaft <NUM> and an inner bearing <NUM>. One end of the hollow shaft <NUM> is connected to the flange plate <NUM>, and an inner ring and an outer ring of the inner bearing <NUM> are respectively connected to the hollow shaft <NUM> and the input shaft <NUM>. In combination with <FIG>, the hollow shaft <NUM> successively passes through the input shaft <NUM>, the output shaft <NUM>, and the braking assembly <NUM> until the hollow shaft <NUM> is inserted into the encoding assembly <NUM>. In this way, it is not only convenient to set the wiring structure of the joint module <NUM>, but also conducive to reducing a wear of the wiring structure. In addition, it is also convenient for the encoding assembly <NUM> to detect the rotation speed and/or angular position of the output end (such as the flange plate <NUM>) of the speed reduction assembly <NUM>.

Illustratively, in combination with <FIG> and <FIG>, the second fastener <NUM> fixes the outer ring of the outer bearing <NUM> on the first annular supporting platform <NUM>, and the flange plate <NUM> is connected with the inner ring of the outer bearing <NUM> by the rigid wheel <NUM>. The fourth fastener <NUM> may fix the annular bending portion <NUM> on the outer ring of the outer bearing <NUM>, to allow performance test being carried out on the speed reduction assembly <NUM>. The second fastener <NUM> passes through the outer ring of the outer bearing <NUM>, the annular bending portion <NUM>, and the lower bearing seat <NUM> in sequence, and connects with the first annular supporting platform <NUM>, to press the speed reduction assembly <NUM> and the lower bearing seat <NUM> on the first annular supporting platform <NUM>. Further, in combination with <FIG>, the lower bearing seat <NUM> (specifically the lower fixing portion <NUM>) defines an avoiding hole <NUM>, and a part of the fourth fastener <NUM> protruding the annular bending portion <NUM> may be arranged in the avoiding hole <NUM> to increase the structural compactness of the joint module <NUM>. Preferably, the avoiding hole <NUM> may pass through the lower fixing portion <NUM> along the axial direction of the output shaft <NUM> to allow the fourth fastener <NUM> to contact the first annular supporting platform <NUM> through the avoiding hole <NUM>, which is conducive to heat dissipation of the speed reduction assembly <NUM>, thereby increasing the reliability of the speed reduction assembly <NUM>.

In some embodiments, in combination with <FIG>, <FIG> and <FIG>, the assembly direction of the fourth fastener <NUM> is opposite to the assembly direction of the first fastener <NUM>, and the assembly direction of the second fastener <NUM> is the same as the assembly direction of the first fastener <NUM>, so each component of the driving assembly <NUM> and the speed reduction assembly <NUM> can be assembled with the housing <NUM> in a certain order.

In some embodiments, there may be a plurality of the first fasteners <NUM>, the second fasteners <NUM>, and the fourth fasteners <NUM> which are spaced apart from each other around the output shaft <NUM>. Between each two adjacent fourth fasteners <NUM> around the output shaft <NUM>, the second fasteners <NUM> are more than the first fasteners <NUM>. In this way, the first fastener <NUM> may fix the lower bearing seat <NUM> on the first annular supporting platform <NUM>, the number of the first fastener <NUM> just need to meet the requirements of capable of carrying out a separate performance test on the driving assembly <NUM>; the fourth fastener <NUM> may fix the annular bending portion <NUM> on the outer ring of the outer bearing <NUM>, the number of the fourth fastener <NUM> just need to meet the requirements of capable of carrying out a separate performance test on the speed reduction assembly <NUM>. Finally, the speed reduction assembly <NUM> and the lower bearing seat <NUM> are both firmly fixed on the first annular supporting platform <NUM> by a large number of second fasteners <NUM>, so as to simplify the structure to the greatest extent and balance the reliability of the structure.

Illustratively, the quantity of the first fastener <NUM> may be four, the quantity of the second fastener <NUM> may be twelve, and the quantity of the fourth fastener <NUM> may be four. Since the first fastener <NUM>, the second fastener <NUM>, and the fourth fastener <NUM> are directly or indirectly related to the lower bearing seat <NUM> in structure, their quantities can be characterized by the quantity of corresponding through holes in the lower fixing portion <NUM>. Based on this, in combination with <FIG>, in addition to the avoiding hole <NUM> corresponding to the fourth fastener <NUM>, the lower fixing portion <NUM> may further define a recessing hole <NUM> corresponding to the first fastener <NUM> and a through hole <NUM> corresponding to the second fastener <NUM>. Obviously, the quantities of the avoiding holes <NUM>, the recessing holes <NUM>, and the through holes <NUM> are four, four, and twelve, respectively. It should be noted that since the speed reduction assembly <NUM> needs to be assembled at the side where the lower bearing seat <NUM> is arranged, a side of the first fastener <NUM> facing the speed reduction assembly <NUM> may be inserted into the lower bearing seat <NUM> or be flush with an end face of the lower bearing seat <NUM>. Obviously, the recessing hole <NUM> may receive the first fastener <NUM> better. Further, a distance between the first fastener <NUM> and a center of the lower bearing seat <NUM> may be less than a distance between the second fastener <NUM> to a center of the lower bearing seat <NUM> along the axial direction of the output shaft <NUM>. That is, the first fastener <NUM> is closer to the output shaft <NUM> along the radial direction of the output shaft <NUM> than the second fastener <NUM>. In other words, along the radial direction of the output shaft <NUM>, the recessing hole <NUM> is closer to the center of the lower bearing <NUM> and further away from the edge of the lower fixing portion <NUM> than the through hole <NUM>, which is conducive to ensuring the structural strength of the area of the lower fixing portion <NUM> where the recessing hole <NUM> is arranged, thereby increasing the structural reliability of the driving assembly <NUM>.

It should be noted that, in other embodiment, the driving assembly <NUM> and/or the speed reduction assembly <NUM> does not require a separate performance test, the first fastener <NUM> and the fourth fastener <NUM> may be omitted, that is, only the second fastener <NUM> is configured to assemble each component of the driving assembly <NUM> and the speed reduction assembly <NUM> with the housing <NUM>.

In combination with <FIG>, both ends of the output shaft <NUM> are connected with the housing <NUM> through respect the lower bearing <NUM> and the upper bearing <NUM>, so the driving assembly <NUM> can give a much more stable output. Therefore, each of the lower bearing <NUM> and the upper bearing <NUM> needs to define a certain clearance after being assembled. However, if the clearance is too small, the output shaft <NUM> cannot rotate smoothly; on the contrary, if the clearance is too large, the output shaft <NUM> cannot rotate stably (such as "displace"). For this reason, the joint module <NUM> may include a first elastic member <NUM> which may press the outer ring of the upper bearing <NUM>, so the clearance between the lower bearing <NUM> and the upper bearing <NUM> can be controlled within a reasonable range. The first elastic member <NUM> may be a wave spring. Based on this, in order to press the first elastic member <NUM>, it is easy for those skilled in the art to come up with the following technical solution: an additional upper pressing ring connected with the upper bearing seat <NUM> is provided to press the first elastic member <NUM>. The difference of the present disclosure is that, in combination with <FIG> and <FIG>, the braking assembly <NUM> is fixed on the upper bearing seat <NUM> and simultaneously presses the first elastic member <NUM> on the outer ring of the upper bearing <NUM>, that is, the braking assembly <NUM> may replace the upper pressing ring, so that the clearance between the lower bearing <NUM> and the upper bearing <NUM> may be controlled within a reasonable range, and the upper pressing ring may be omitted, thus the joint module <NUM> is much more compact in structure, and the cost of the joint module <NUM> is also reduced.

Illustratively, with reference to <FIG>, the braking assembly <NUM> includes a mounting seat <NUM> connected to the upper bearing seat <NUM>, a second elastic member <NUM> and a magnet exciting coil <NUM> both arranged in the mounting seat <NUM>, and an armature plate <NUM>, a friction plate <NUM> and a cover plate <NUM> which are arranged layer by layer in sequence along the axial direction of the output shaft <NUM>. That is, the armature plate <NUM> and the cover plate <NUM> are respectively arranged on both sides of the friction plate <NUM> in the axial direction of the output shaft <NUM>. The friction plate <NUM> is connected with the output shaft <NUM> to rotate along with the output shaft <NUM>. The cover plate <NUM> may be connected with the mounting base <NUM> to remain relatively stationary. The armature plate <NUM> and the friction plate <NUM> may be separate members, that is, the armature plate <NUM> and the friction plate <NUM> is capable of moving to each other. The armature plate <NUM> and the friction plate <NUM> may also be connected with each other by at least one of the assembly methods including gluing, clamping, and threaded connection, that is, the armature plate <NUM> and the friction plate <NUM> may remain relatively stationary.

The working principle of the braking assembly <NUM> may be that: in combination with <FIG>, when the magnet exciting coil <NUM> is powered off, the armature plate <NUM> pushes the friction plate <NUM> to move along the axial direction of the output shaft <NUM> to contact the cover plate <NUM> under the elastic force of the second elastic member <NUM>, so that the output shaft <NUM> switches from the rotating state to the braking state, that is, the output shaft <NUM> stops rotating; when the magnet exciting coil <NUM> is energized, magnetic field is generated by the magnet exciting coil <NUM> to act on the armature plate <NUM>, making the friction plate <NUM> separate from the cover plate <NUM> to release the braking state of the output shaft <NUM>, that is, the output shaft <NUM> continues to rotate. In this way, compared with the related art in which the output shaft <NUM> is braked by a pin, the braking assembly <NUM> in the present disclosure brakes the output shaft <NUM> by the friction resistance, the braking assembly <NUM> in the present disclosure has the advantages of no idle stroke, fast response, no abnormal noise, etc. After the magnet exciting coil <NUM> is powered off, the elastic potential energy stored in the second elastic member <NUM> may not only push the armature plate <NUM> and the friction plate <NUM>, but also allow a certain positive pressure to be generated between the armature plate <NUM> and the friction plate <NUM>, and between the friction plate <NUM> and the cover plate <NUM>, thus a preset friction resistance can be provided to maintain the braking state of the output shaft <NUM>. Further, after the magnet exciting coil <NUM> is energized, the magnetic field generated by the magnet exciting coil <NUM> may attract the armature plate <NUM> to keep the armature plate <NUM> away from the cover plate <NUM>, so as to at least release the positive pressure between the friction plate <NUM> and the cover plate <NUM>.

It should be noted that, after the braking assembly <NUM> is assembled, the mounting base <NUM> is fixed on the upper fixing portion <NUM>, and the braking assembly <NUM> presses the first elastic member <NUM> through the mounting base <NUM>. Correspondingly, the second elastic member <NUM> is arranged on the side of the mounting base <NUM> that is away from the first elastic member <NUM>; the mounting base <NUM> is limited on the inner side of the upper ring shaped limiting portion <NUM> along radial direction. In some embodiments, the mounting base <NUM> may be made of soft magnetic material which is the same as the armature plate <NUM>, so as to adjust the magnetic field generated by the magnet exciting coil <NUM> to make the magnetic field be more concentrated.

The braking assembly <NUM> includes a guiding column <NUM> supported between the mounting base <NUM> and the cover plate <NUM>. The armature plate <NUM> may be close to or far from the cover plate <NUM> under the guidance of the guiding column <NUM> to avoid the braking assembly <NUM> from being stuck. The quantity of guiding column <NUM> may be more than one, and the guiding columns <NUM> may be spaced apart from each other around the output shaft <NUM>, for example, three guiding columns <NUM> may be evenly spaced apart from each other around the output shaft <NUM>.

In some embodiments, the mounting base <NUM> includes a bottom wall <NUM>, an inner wall <NUM> and an outer wall <NUM> both connected with the bottom wall <NUM>. The inner wall <NUM> is arranged around the output shaft <NUM>, and the outer wall <NUM> is arranged around the inner wall <NUM> and extends in a same direction as the inner wall <NUM>. Correspondingly, the guiding column <NUM> may be supported between the outer wall <NUM> and the cover plate <NUM>. Based on this, the armature plate <NUM> may be stopped by at least one of the inner wall <NUM> and the outer wall <NUM> when the armature plate <NUM> is far away from the cover plate <NUM> under the action of the magnetic field generated by the magnet exciting coil <NUM>, so as to limit the movement of the armature plate <NUM>.

In some embodiments, the second elastic member <NUM> is arranged in a blind hole defined in the outer wall <NUM>, and the magnet exciting coil <NUM> is arranged between the inner wall <NUM> and the outer wall <NUM>, for example, the magnet exciting coil <NUM> is wound on the inner wall <NUM>. The quantity of the second elastic members <NUM> may be more than one, and the second elastic members <NUM> is spaced apart from each other around the output shaft <NUM>, for example, four second elastic members <NUM> is evenly spaced apart from each other around the output shaft <NUM>.

In some embodiments, the second elastic member <NUM> and the magnet exciting coil <NUM> is arranged between the inner wall <NUM> and the outer wall <NUM>. For example, the quantities of the second elastic member <NUM> and the magnet exciting coil <NUM> are more than one, and the second elastic members <NUM> and the excitation coils <NUM> are respectively spaced apart from each other around the output shaft <NUM>.

In combination with <FIG>, the driving assembly <NUM> includes an adapter <NUM> connected with the output shaft <NUM>, and the friction plate <NUM> is sleeved on the adapter <NUM>. In combination with <FIG>, viewed along the axial direction of the output shaft <NUM>, an outer contour of the adapter <NUM> and an inner contour of the friction plate <NUM> are matched with each other and are non-circular, to allow the friction plate <NUM> to rotate with the adapter <NUM>, and allow the friction plate <NUM> to move relative to the adapter <NUM> along the axial direction of the output shaft <NUM>. For example, the inner contour of the friction plate <NUM> is a first square when viewed along the axial direction of the output shaft <NUM>, and the four corners of the first square are rounded corners; the outer contour of the adapter <NUM> is a second square when viewed along the axial direction of the output shaft <NUM>, and the four corners of the second square are rounding chamfer. In this way, the corners of the adapter <NUM> may effectively avoid the corners of the friction plate <NUM>, so as to prevent the friction plate <NUM> from getting stuck when moving along the adapter <NUM>, so the reliability of the braking assembly <NUM> is improved, further, the area of the friction plate <NUM> may be increased as much as possible, so that the braking assembly <NUM> can respond faster.

When the output shaft <NUM> is switched from the braking state to the rotating state, the friction plate <NUM> rotates with the adapter <NUM>, then rotates with the output shaft <NUM>, to prevent the braking assembly <NUM> from applying unnecessary resistance to the rotation of the output shaft <NUM>; when the output shaft <NUM> is switched from the rotating state to the braking state, the friction plate <NUM> moves along the axial direction of the output shaft <NUM> with respect to the adapter <NUM> under the push of the second elastic member <NUM> and the armature plate <NUM>, to contact the cover plate <NUM>, then the output shaft <NUM> is stopped by the friction resistance. In other words, the adapter <NUM> has no freedom relative to the output shaft <NUM>, while the friction plate <NUM> has freedom relative to the adapter <NUM> along the axial direction of the output shaft <NUM>. In this way, compared with that the adapter <NUM> is integratedly formed with the output shaft <NUM>, the adapter <NUM> and the output shaft <NUM> are separately processed and then assembled, which not only simplifies the structure of the output shaft <NUM> and reduces the difficulty of processing the output shaft <NUM>, but also facilitates the selection of different materials for the adapter <NUM> and the output shaft <NUM> for reducing the cost of the joint module <NUM>.

In some embodiments, in combination with <FIG>, the encoding assembly <NUM> may be configured to detect the rotation state (including at least one of the rotation speed and the angular position of the output shaft <NUM>) of the driving assembly <NUM>. The encoding assembly <NUM> includes an encoding disk 1151A and a reading head 1152A which cooperates with the encoding disk 1151A to detect the rotation speed and/or the angular position of the output shaft <NUM>. Based on this, the encoding assembly <NUM> may be a magneto-electric encoder, and the encoding disk 1151A is correspondingly set as a magnetic grid disk; the encoding assembly <NUM> may also be a photoelectric encoder, and the encoding disk 1151A is correspondingly set as a grating disk. Both the magneto-electric encoder and the photoelectric encoder may be further arranged as the incremental or absolute type according to the actual needs. The relevant principles and specific structures are well known to those skilled in the art, and will not be repeated here. It is worth noting that compared with the magneto-electric encoder, the photoelectric encoder has more stringent requirements on the external environment. For example, the photoelectric encoder has higher dust prevention requirements, which will be explained later.

In some embodiments, the encoding disc 1151A and the adapter <NUM> may be separately connected with the output shaft <NUM> to rotate with the output shaft <NUM>, so the interference of the braking assembly <NUM> to the encoding assembly <NUM> is reduced. Illustratively, the encoding disk 1151A and the adapter <NUM> may be connected with the output shaft <NUM> through their respective adapters, and the quantity of adapters is two.

In some embodiments, the encoding disk 1151A connects with the adapter <NUM>, and the encoding disk 1151A connects with the output shaft <NUM> by the adapter <NUM>. That is, the encoding disk 1151A and the friction plate <NUM> both connect with the output shaft <NUM> by the adapter <NUM>, so that the adapter <NUM> has two functions, which is conducive to simplifying the structure of the joint module <NUM>. Based on this and in combination with <FIG>, after the driving assembly <NUM> is assembled with the housing <NUM>, the braking assembly <NUM> is assembled with the driving assembly <NUM> first; then the encoding disc 1151A and the adapter <NUM> as a whole is assembled with the braking assembly <NUM>; and the bracket <NUM>, the reading head 1152A and the circuit board of the reading head 1152A, and other structures as a whole are assembled with the housing <NUM> or the upper bearing seat <NUM>. In this way, compared with the encoding disk 1151A and the adapter <NUM> connected with the output shaft <NUM> by their respective adapters, both the encoding disk 1151A and the friction plate <NUM> in the present disclosure are connected with the output shaft <NUM> by the adapter <NUM>, so the adapter <NUM> only needs to be assembled and disassembled once, which is beneficial to improve the production efficiency.

Illustratively, in combination with <FIG>, the adapter <NUM> includes a cylindrical body <NUM>, an inner flange portion <NUM> and an outer flange portion <NUM> both connected with the cylindrical body <NUM>, and the outer flange portion <NUM> and the inner flange portion <NUM> extend in reverse directions. In combination with <FIG>, the outer contour of the cylindrical body <NUM> is non-circular but a square with four chamfering corners when viewed along the axial direction of the output shaft <NUM>, and the friction plate <NUM> sleeves on the cylindrical body <NUM> to rotate with the adapter <NUM> or move along the axial direction of the output shaft <NUM> relative to the adapter <NUM>; the encoding disc 1151A connects with the outer flange portion <NUM> to rotate with the adapter <NUM>. Preferably, the adapter <NUM> includes an annular flange <NUM> connected with the outer flange portion <NUM>. When the encoding disk 1151A connects with the outer flange portion <NUM>, the encoding disk 1151A further sleeves on the annular flange <NUM> to limit the encoding disk 1151A in radial direction by the annular flange <NUM>. Further, with reference to <FIG>, the output shaft <NUM> is inserted into the cylindrical body <NUM>, and the end face of the output shaft <NUM> butts with the inner flange portion <NUM>. For example, the inner flange portion <NUM> is fixed on the end of the upper fixing section <NUM> by the fifth fastener <NUM> to allow the adapter <NUM> to rotate with the output shaft <NUM>. Since the output shaft <NUM> is inserted into the cylindrical body <NUM>, the cylindrical body <NUM> may limit the output shaft <NUM> in radial direction, and the coaxiality between the adapter <NUM> and the output shaft <NUM> is also increased.

It should be noted that the first fastener to the fifth fastener in the present disclosure may be bolts, for example, hexagon heads bolts, round heads bolts, square heads bolts, or countersunk heads bolts, etc..

In some embodiments, in combination with <FIG>, the encoding assembly <NUM> may be configured to detect the rotation state (including at least one of the rotation speed and angular position of the flange plate <NUM>) of the speed reduction assembly <NUM>. The encoding assembly <NUM> includes an encoding disk 1151B connected with the hollow shaft <NUM> and a reading head 1152B matched with the encoding disk 1151B. The reading head 1152B detects the rotation speed and/or the angular position of the flange plate <NUM> when the encoding disk 1151B rotates with the hollow shaft <NUM>. Similarly, the encoding disk 1151B may be a magnetic grating disk or a grating disk.

Illustratively, in combination with <FIG> and <FIG>, the joint module <NUM> includes a bracket <NUM> connected with the housing <NUM>, and the bracket <NUM> covers the braking assembly <NUM>, that is, the bracket <NUM> is arranged outside of the braking assembly <NUM>, so as to facilitate the arrangement of the encoding assembly <NUM>, and further simplify the structure of the joint module <NUM>. In other words, the bracket <NUM> and the braking assembly <NUM> are supported on a same side of the upper fixing portion <NUM>. The reading head 1152A and its circuit board are connected with the bracket <NUM>, and the reading head 1152B and its circuit board are also connected with the bracket <NUM>. In this way, it is beneficial to adjust the axial spacing between the reading head 1152A and the encoder 1151A along the axial direction of the output axis <NUM>, and the axial spacing between the reading head 1152B and the encoder 1151B along the axial direction of the output axis <NUM>, thereby increasing the reliability of the encoder assembly <NUM>. Of course, the reading head 1152A and the reading head 1152B may also be set on a same circuit board, and the encoding disk 1151A, the circuit board and the encoding disk 1151B are set at intervals along the axial direction of the output shaft <NUM>, which is conducive to simplifying the structure of the encoding assembly <NUM>.

In some embodiments, in the radial direction of the output shaft <NUM>, the braking assembly <NUM> is limited to the inner side of the upper annular limiting portion <NUM>, and the bracket <NUM> is limited to the outer side of the upper annular limiting portion <NUM>, which is not only conducive to improving the assembly accuracy of the braking assembly <NUM> and the bracket <NUM>, but also conducive to simplifying the structure of the joint module <NUM>. In the axial direction of the output shaft <NUM>, compared with the outer support surface of the upper fixing portion <NUM> for supporting the bracket <NUM>, the inner support surface of the upper fixing portion <NUM> for supporting the braking assembly <NUM> is closer to the upper bearing, which is conducive to increasing the structural compactness of the joint module <NUM>.

Illustratively, with reference to <FIG>, the bracket <NUM> includes a cylindrical body <NUM>, an outer bottom wall <NUM> and an inner top wall <NUM> which are respectively obliquely connected with the two ends of the cylindrical body <NUM>, and the outer bottom wall <NUM> and the inner top wall <NUM> extend in reverse directions. The cylindrical body <NUM> is arranged outside of the braking assembly <NUM>. The outer bottom wall <NUM> is connected with the upper fixing portion <NUM>, and is limited to the outer side of the upper annular limiting portion <NUM> in radial direction. The reading head 1152A, reading head 1152B and their respective circuit boards are all connected with the inner top wall <NUM>. Of course, the bracket <NUM> may not include the inner top wall <NUM>, as long as the encoding assembly <NUM> is capable of be assembled on the bracket <NUM>. Furthermore, the inner side of the corner defined by the outer bottom wall <NUM> and the cylindrical body <NUM> may define an avoiding groove <NUM>, the upper annular limiting portion <NUM> is received in the avoiding groove <NUM> after the bracket <NUM> is assembled with the upper bearing seat <NUM>, so at to improve the compact of the joint module <NUM>, especially in the radial direction of the output shaft <NUM>.

It should be noted that, in an embodiment as shown in <FIG>, for the sake of differentiation, the encoding assembly for detecting the rotation state of the driving assembly <NUM> may be defined as the first encoding assembly, and the encoding assembly for detecting the rotation state of the speed reduction assembly <NUM> may be defined as the second encoding assembly. The first encoding assembly includes the encoding disk 1151A and the reading head 1152A, and the second encoding assembly includes the encoding disk 1151B and the reading head 1152B.

Based on the above related description, the encoding assembly <NUM> may be configured to detect the rotation state (including the rotation speed and/or the angular position) of a shaft to be detected (such as an output shaft <NUM> or a hollow shaft <NUM>). In combination with <FIG>, when the encoding assembly <NUM> is configured to detect the rotation state of the output shaft <NUM>, the encoding disk 1151A and the reading head 1152A are two separate structural members, which are respectively assembled with the adapter <NUM> and the bracket <NUM> one by one, so that the corresponding position between the encoding disk 1151A and the reading head 1152A (especially the axial spacing of the output shaft <NUM>) is important to the subsequent assembly accuracy. When the encoding assembly <NUM> is configured to detect the rotation state of the output shaft <NUM>, a similar problem also exists, which may lead to a poor detection accuracy of the encoding assembly <NUM>. In combination with <FIG> and <FIG>, the difference of the present disclosure is that, the encoding assembly <NUM> is integratedly designed, that is, the encoding assembly <NUM> is an integrated encoding assembly, so that the axial spacing between the encoding disk 1151A and the reading head 1152A (or the axial spacing between the encoding disk 1151B and the reading head 1152B) may be debugged and determined before the encoding assembly <NUM> is assembled to the joint module <NUM>, as such, the detection accuracy of the encoding assembly <NUM> is improved. Furthermore, in combination with <FIG>, for the convenience of description, the present disclosure takes the output shaft <NUM> as the shaft to be detected as an example.

Illustratively, in combination with <FIG> and <FIG>, the encoding assembly <NUM> includes a base <NUM>, a rotating shaft <NUM>, the encoding disk 1151A, and the reading head 1152B. The rotating shaft <NUM> is rotatably arranged on the base <NUM>, and connected with the shaft to be detected, such as the output shaft <NUM> or the hollow shaft <NUM>. The encoding disk 1151A is connected with the rotating shaft <NUM>, and the reading head 1152B and its circuit board are relatively fixed with the base <NUM>, making the encoding assembly <NUM> be a modular structure. In this way, before the encoding module <NUM> is assembled and used, the axial spacing between the encoding disk 1151A and the reading head 1152A may be debugged and determined, which may improve the detection accuracy of the encoding module <NUM>. The base <NUM> is arranged to keep stationary relative to the output shaft <NUM>, and the rotating shaft <NUM> is arranged to rotate synchronously with the output shaft <NUM>, for the encoding assembly <NUM> to detect the rotation speed and/or the angular position of the output shaft <NUM>.

In some embodiments, in combination with <FIG>, the rotating shaft <NUM> is hollow, and the hollow shaft <NUM> may be partially inserted into the rotating shaft <NUM> after passing through the input shaft <NUM> and the output shaft <NUM>, to facilitate the setting of the wiring structure of the joint module <NUM>.

Illustratively, in combination with <FIG>, one of the rotating shaft <NUM> and the output shaft <NUM> is partially inserted into the other, and a pair of contact surfaces are formed. When the rotating shaft <NUM> is partially inserted into the output shaft <NUM>, as shown in <FIG>, the pair of contact surfaces refer to the outer contour surface of the rotating shaft <NUM> and the inner contour surface of the output shaft <NUM>, and the outer contour surface of the rotating shaft <NUM> contacts the inner contour surface of the output shaft <NUM>; on the contrary, when the output shaft <NUM> is partially inserted into the rotating shaft <NUM>, in combination with (b) in <FIG>, the pair of contact surfaces refer to the outer contour surface of the output shaft <NUM> and the inner contour surface of the rotating shaft <NUM>, and the outer contour surface of the output shaft <NUM> contacts the inner contour surface of the rotating shaft <NUM>. Furthermore, the cross-sectional area of the contacted surface perpendicular to the axial direction of the output shaft <NUM> gradually increases or decreases along the axial direction of the output shaft <NUM>. After being fixed, the base <NUM> provides a pressing force to the pair of contact surfaces along the axial direction of the output shaft <NUM>, causing the rotating shaft <NUM> to rotate with the output shaft <NUM> under a friction force between the pair of contact surfaces. Specifically, the pressing force F may be decomposed into the first component force F1 perpendicular to the pair of contact surfaces and the second component force F2 parallel to the pair of contact surfaces, and the static friction coefficient of the rotating shaft <NUM> or the output shaft <NUM> at the pair of contact surfaces is µ, and the friction force f of the rotating shaft <NUM> and the output shaft <NUM> at the pair of contact surfaces may be a product of the first component force F1 and the static friction coefficient µ. In combination with <FIG>, the present disclosure takes the technical solution of partially inserting the rotating shaft <NUM> into the output shaft <NUM> as an example to describe, which is beneficial to reduce the radial size of the encoding assembly <NUM>.

Compared with the direct connection between the rotating shaft <NUM> and the output shaft <NUM> through fasteners such as bolts, the embodiment does not need to consider the minimum wall thickness of the rotating shaft <NUM> or the output shaft <NUM> and the space occupied by the fasteners, so the rotating shaft <NUM> and the output shaft <NUM> can be designed much more flexible, and the encoding assembly <NUM> and the driving assembly <NUM> are much more compact. Compared with the direct connection between the rotating shaft <NUM> and the output shaft <NUM> by glue, the embodiment does not have the problem of glue aging, and the overall structure is more reliable. Compared with the rotating shaft <NUM> and the output shaft <NUM> being non-circular holes and direct inserting match, the embodiment does not exist a mating gap, so the rotating shaft <NUM> may rotate with the output shaft <NUM> more synchronously, and the encoding assembly <NUM> may be assembled and disassembled more conveniently.

It should be noted that, in order to increase the detecting reliability of the encoding assembly <NUM> detecting the rotating state of the output shaft <NUM>, the coaxiality between the rotating shaft <NUM> and the output shaft <NUM> is high, so that the axis of the rotating shaft <NUM> and the axis of the output shaft <NUM> may be simply considered to be coincided with each other. Therefore, the axial direction of the output shaft <NUM> may be simply regarded as the axial direction of the rotating shaft <NUM>, and the radial direction of the output shaft <NUM> may also be simply regarded as the radial direction of the rotating shaft <NUM>.

In some embodiments, in combination with <FIG>, the other end of the rotating shaft <NUM> away from the encoding disk 1151A passes through the adapter <NUM> under the guidance of the adapter <NUM> and partially extends into the output shaft <NUM>, so the adapter <NUM> can limit the rotating shaft <NUM> in the radial direction of the output shaft <NUM>, which is conducive to increasing the coaxiality between the rotating shaft <NUM> and the output shaft <NUM>, especially when the end of the rotating shaft <NUM> is designed as a gradual structure. In combination with the above description, the friction plate <NUM> may also sleeve on the adapter <NUM> and connect with the output shaft <NUM>, so that the adapter <NUM> has two functions, which is conducive to simplifying the structure of the joint module <NUM>.

Illustratively, in combination with <FIG>, the adapter <NUM> is designed as a ring structure, and the rotating shaft <NUM> may be inserted into the output shaft <NUM> along the inner ring surface of the adapter <NUM>. The radius of the inner ring surface remains unchanged in the axial direction of the output shaft <NUM>. Correspondingly, the outer diameter of the part of the rotating shaft <NUM> that fits with the adapter <NUM> remains unchanged in the axial direction of the output shaft <NUM>. In this way, compared with the gradual structure, the cylindrical equal diameter structure is more conducive to increasing the coaxiality between the rotating shaft <NUM> and the output shaft <NUM>.

Similarly, the adapter <NUM> includes a cylindrical body <NUM> and an inner flange portion <NUM> connected with the cylindrical body <NUM>. The radius of the inner ring surface of the cylindrical body <NUM> remains unchanged in the axial direction of the output shaft <NUM>, so that the adapter <NUM> can guide the rotating shaft <NUM>. The outer contour of the cylindrical body <NUM> is non-circular when viewed along the axial direction of the output shaft <NUM>, so that the friction plate <NUM> can sleeve on the adapter <NUM>.

Furthermore, the inner flange portion <NUM> may be provided with a plurality of counter bores <NUM> spaced apart from each other around the rotating shaft <NUM>, for example, the quantity of counter bores <NUM> is six, so the fifth fastener <NUM> can fix the inner flange portion <NUM> on the output shaft <NUM> by inserting into the counter bore <NUM>. In other words, the fifth fastener <NUM> does not protrude out of the adapter <NUM> in the axial direction of the output shaft <NUM>, which is conducive to increasing the structural compactness of the joint module <NUM>.

Illustratively, in combination with <FIG> and <FIG>, the base <NUM> defines a bearing hole <NUM>. The encoding assembly <NUM> includes a bearing <NUM> inserted in the bearing hole <NUM>, so that the rotating shaft <NUM> may be rotatably arranged on the base <NUM>. Of course, if the speed of the shaft to be detected is not high, for example, the speed of the hollow shaft <NUM> is much smaller than that of the output shaft <NUM>, the encoding assembly <NUM> may not include the bearing <NUM>, that is, the rotating shaft <NUM> is directly matched with the bearing hole <NUM>, for example, clearance fit, and the rotating shaft <NUM> can also be rotatably arranged on the base <NUM>.

In some embodiments, the rotating shaft <NUM> includes a connecting portion <NUM>, an inserting portion <NUM>, and a protruding portion <NUM>, the inserting portion <NUM> and the protruding portion <NUM> are respectively connected to both ends of the connecting portion <NUM>. The connecting portion <NUM> may be inserted in the inner ring of the bearing <NUM>, and the inserting portion <NUM> and the protruding portion <NUM> are respectively extend from both sides of the bearing <NUM>. The protruding portion <NUM> presses the inner ring of the bearing <NUM> along the axial direction of the output shaft <NUM>, and the encoding disk 1151A connects with the protruding portion <NUM>. Furthermore, the outer diameter of the inserting portion <NUM> gradually decreases in the axial direction of the output shaft <NUM> and in the direction away from the protruding portion <NUM>, the inserting portion <NUM> may be inserted into the output shaft <NUM>, thereby forming a pair of contact surfaces. Based on the above related description, the outer diameter of the inserting portion <NUM> may first remain unchanged and then gradually decrease in the axial direction of the output shaft <NUM> and in the direction away from the protruding portion <NUM>, so the inserting portion <NUM> may pass through the adapter <NUM> and partially insert in the output shaft <NUM> under the guidance of the adapter <NUM>.

Illustratively, in combination with <FIG>, an angle θ between the outer contour of the inserting portion <NUM> and the axial direction of the output shaft <NUM> may be between <NUM>° and <NUM>°. When the value of the pressing force F and other parameters are fixed, the value of the angle θ determines the value of the first component force F1, that is, F1=F*sinθ. It is worth noting that, although the larger the angle θ is, the greater the first component force F1 is, which is more conducive to providing sufficient friction. However, the outer contour surface of the inserting portion <NUM> and the inner contour surface of the output shaft <NUM> may become sharper, which will reduce the structural strengths of ends of the inserting portion <NUM> and the output shaft <NUM>. Conversely, although the smaller the angle θ is, the better to ensure the structural strengths of the ends of the inserting portion <NUM> and the output shaft <NUM>, however, there may be a risk that the rotating synchronicity between the rotating shaft <NUM> and the output shaft <NUM> becomes worse.

In some embodiments, the ratio of an absolute value difference between the minimum outer diameter and the maximum outer diameter of the inserting portion <NUM> to the maximum outer diameter of the inserting portion <NUM> may be between <NUM> and <NUM>, allowing the angle θ being within an appropriate range. In addition, the angle θ with a certain value is conducive to ensuring the structural strengths of the ends of the insertion portion <NUM> and the output shaft <NUM>.

In some embodiments, the depth of the inserting portion <NUM> inserting into the output shaft <NUM> in the axial direction of the output shaft <NUM> may be between <NUM> and <NUM>, allowing the angle θ to be within an appropriate range.

In combination with <FIG> and <FIG>, when viewed along the axial direction of the output shaft <NUM>, the edge area of the base <NUM> defines a plurality of mounting holes <NUM> spaced apart from each other around the rotating shaft <NUM>, and the base <NUM> is fixed on the housing <NUM> or the bracket <NUM> by fixing fasteners such as bolts in the mounting holes <NUM>. There is a first distance in the radial direction of the output shaft <NUM> between the center of the mounting hole <NUM> and the center of the bearing hole <NUM>, and the mounting hole <NUM> moves a second direction along the axial direction of the output shaft <NUM> before and after the base <NUM> is fixed. The first distance may be between <NUM> and <NUM>, and the second distance may be between <NUM> and <NUM>. It should be noted that, in the embodiment where the base <NUM> is fixed on the bracket <NUM>, before the base <NUM> is fixed, there is a gap between the mounting hole <NUM> and the bracket <NUM> in the axial direction of the output shaft <NUM>, and the gap may be the second distance. Referring to <FIG>, when the parameters such as the angle θ and the stiffness of the base <NUM> are fixed values, the ratio of the second distance to the first distance determines the pressing force F. It is worth noting that although the larger the ratio is, the greater the pressing force F is, which is more conducive to providing sufficient friction. However, there is also a risk that the output shaft <NUM> may be "jacked" along its axis. On the contrary, although the smaller the ratio is, the better to avoid the output shaft <NUM> being "jacked" along its axis, but there is also a risk of resulting an insufficient pressing force F.

In some embodiments, in combination with <FIG>, the protruding portion <NUM> includes a first protruding section <NUM> connected with the connecting portion <NUM>, and a second protruding section <NUM> connected with the first protruding section <NUM>. The first protruding section <NUM> surrounds the connecting portion <NUM>, and the second protruding section <NUM> surrounds the first protruding section <NUM>. The thickness of the second protruding section <NUM> in the axial direction of the output shaft <NUM> may be less than that of the first protruding section <NUM> in the axial direction of the output shaft <NUM>, so that the first protruding section <NUM> presses the inner ring of the bearing <NUM> along the axial direction of the output shaft <NUM>, and the second protruding section <NUM> are spaced apart from the outer ring of the bearing <NUM> and the base <NUM> in the axial direction of the output shaft <NUM>, which is beneficial to avoid unnecessary collision between the rotating shaft <NUM> and the bearing <NUM> or the base <NUM>. Similarly, the encoding assembly <NUM> includes a snap ring sleeved on the connecting portion <NUM>, the snap ring and the first protruding section <NUM> clamp the inner ring of the bearing <NUM>. Furthermore, the encoding disk 1151A may be connected with the side of the second protruding section <NUM> away from the bearing <NUM>, and the side of the encoding disk 1151A away from the second protruding section <NUM> may not protrude from the first protruding section <NUM> in the axial direction of the output shaft <NUM>, which is conducive to avoiding structural interference or collision between the encoding disk 1151A and other structural members, especially when the encoding disk 1151A is a grating disk. In other words, the encoding disk 1151A is ring shaped and may sleeve on the rotating shaft <NUM>.

In some embodiments, at least two bearings <NUM> may be stacked in the axial direction of the output shaft <NUM>, so the coaxiality of the rotating shaft <NUM> with respect to the bearing hole <NUM> is increased, and the rotating shaft <NUM> rotates more smoothly with respect to the base <NUM>. A spacer <NUM> may be clamped between the outer rings or inner rings of two adjacent bearings <NUM>. The spacer <NUM> makes that the gap between the outer rings of two adjacent bearings <NUM> is different from the gap between the inner rings of two adjacent bearings <NUM>, that is, the outer ring and the inner ring of bearing <NUM> are staggered for a distance in the axial direction of the output shaft <NUM>, which is conducive to controlling the clearance of the bearing <NUM> within a reasonable range, thus increasing the rotation stability of the rotating shaft <NUM>.

Based on the above related description, in an embodiment as shown in <FIG>, the encoding assembly <NUM> may be a magneto-electric encoder or a photoelectric encoder, and the encoding disk 1151A is correspondingly a magnetic grating disk or a grating disk. Compared with the magneto-electric encoder, the photoelectric encoder has more stringent requirements on the external environment, for example, the photoelectric encoder has a higher dust prevention requirement. The encoding disk 1151A which is a grating disk will be illustrated in the following.

In combination with <FIG> and <FIG>, the protruding portion <NUM> completely covers the bearing hole <NUM> when the protruding portion <NUM> is orthogonally projected to the base <NUM> along the axial direction of the output shaft <NUM>, so as to prevent external matters (such as grinding dust generated by the friction plate <NUM> during operation) from entering into the encoding assembly <NUM> through the bearing hole <NUM> to pollute the encoding disk 1151A, which is conducive to increasing the dust prevention performance of the encoding assembly <NUM>. Specifically, when the first protruding section <NUM> is orthogonally projected onto the base <NUM> along the axial direction of the output shaft <NUM>, the orthographic projection falls into the bearing hole <NUM>. When the second protruding section <NUM> is orthogonally projected onto the base <NUM> along the axial direction of the output shaft <NUM>, the orthographic projection partially overlaps with the base <NUM>, allowing the protruding portion <NUM> to completely cover the bearing hole <NUM>.

Illustratively, with reference to <FIG>, the base <NUM> includes a middle step portion <NUM> and an inner step portion <NUM> connected with the middle step portion <NUM>. The inner step portion <NUM> is closer to the rotating shaft <NUM> than the middle step portion <NUM> in the radial direction of the output axis <NUM>, and the thickness of the inner step portion <NUM> in the axial direction of the output shaft <NUM> is greater than that of the middle step portion <NUM> in the axial direction of the output shaft <NUM>. The bearing hole <NUM> is defined in the inner step portion <NUM> to allow at least two bearings <NUM> to be stacked in the bearing hole <NUM> along the axial direction of the output shaft <NUM>, thereby increasing the coaxiality of the rotating shaft <NUM> with respect to the bearing hole <NUM>, making the rotating shaft <NUM> rotate with respect to the base <NUM> stably. Furthermore, in combination with <FIG>, when the encoding disk 1151A is orthographically projected to the base <NUM> along the axial direction of the output shaft <NUM>, the orthographic projection partially overlaps with the middle step portion <NUM>, and the distance between the encoding disk 1151A and the middle step portion <NUM> in the axial direction of the output shaft <NUM> is greater than the distance between the encoding disk 1151A and the inner step portion <NUM> in the axial direction of the output shaft <NUM>. In other words, there is a greater safety clearance between the edge area of the encoding disk 1151A away from the rotating shaft <NUM> and the base <NUM> in the axial direction of the output shaft <NUM>, which is conducive to avoiding unnecessary collision between the encoding disk 1151A and the base <NUM>, especially when the encoding disk 1151A is a grating disk. As such, by way of arranging at least a part of the base 1153as a ladder structure, both the rotation stability of the rotating shaft <NUM> and the anti-collision of the encoding disk 1151A may be ensured, namely, "killing two birds with one stone". Of course, the weight of the encoding assembly <NUM> can also be reduced to a certain extent.

In some embodiments, the second protruding section <NUM> is spaced apart from the outer ring of the bearing <NUM> and the inner step portion <NUM> in the axial direction of the output shaft <NUM>, to avoid unnecessary collision between the rotating shaft <NUM> and the bearing <NUM> or the base <NUM>. When the second protruding section <NUM> is orthogonally projected to the base <NUM> along the axial direction of the output shaft <NUM>, the orthographic projection may partially overlap with the inner step portion <NUM>, that is, the protruding portion <NUM> completely covers the bearing hole <NUM>, which is conducive to increasing the dust-proof performance of the encoding assembly <NUM>.

Referring to <FIG>, the protruding portion <NUM> includes a third protruding portion <NUM> obliquely connected with the second protruding section <NUM>. The third protruding portion <NUM> surrounds the inner step portion <NUM> to prolong the path of external matters entering the encoding assembly <NUM>, which is also conducive to increasing the dust prevention performance of the encoding assembly <NUM>. The middle step portion <NUM> defines a groove <NUM> surrounding the inner step portion <NUM>, and the third protruding section <NUM> may be partially inserted into the groove <NUM>. In this way, it is not only conducive to prolong the path of external matters entering the encoding assembly <NUM>, but also conducive to collecting external matters that have passed through the bearing <NUM> into the groove <NUM>, thus increasing the difficulty of external matters further entering the encoding assembly <NUM>. It should be noted that, whether the middle step portion <NUM> defines the groove <NUM> or not, the third protruding portion <NUM> is always spaced apart from the middle step portion <NUM> in the axial direction of the output shaft <NUM> to avoid unnecessary collision between the rotating shaft <NUM> and the base <NUM>.

In combination with <FIG> and <FIG>, the encoding assembly <NUM> includes an upper cover <NUM>, a circuit board <NUM>, and a light source <NUM>. The upper cover <NUM> connects with the base <NUM> to form a cavity configured for receiving the encoding disk 1151A, the circuit board <NUM>, and other structural members. The light source <NUM> is configured to transmit the detection signal to the encoding disk 1151A, and the reading head 1152A is set on the circuit board <NUM> and configured to receive the detection signal. Furthermore, the light source <NUM> and the reading head 1152A (and the circuit board <NUM> connected to the reading head 1152A) are respectively arranged on opposite sides of the encoding disk 1151A, allowing the reading head 1152A to receive the detection signal transmitted by the light source <NUM> and has passed through the encoding disk 1151A, thus forming an opposed optical encoder. The light source <NUM> and the reading head 1152A (and the circuit board <NUM> connected to the reading head 1152A) may also be set on a same side of the encoding disk 1151A, allowing the reading head 1152A to receive the detection signal transmitted by the light source <NUM> and has been reflected by the encoding disk 1151A, thus forming a reflective optical encoder.

Illustratively, the upper cover <NUM> includes an outer cylindrical sidewall <NUM> and a top cover <NUM> connected to one end of the outer cylindrical sidewall <NUM>, the outer cylindrical sidewall <NUM> surrounds the middle step portion <NUM>. Since the thickness of the middle step portion <NUM> in the axial direction of the output shaft <NUM> is generally greater than the thickness of the outer cylindrical sidewall <NUM> in the radial direction of the output shaft <NUM>, compared with arranging the outer cylindrical sidewall <NUM> on the middle step portion <NUM>, the outer cylindrical sidewall <NUM> surrounding the middle step portion <NUM> is more conducive to increasing the matching area between the outer cylindrical sidewall <NUM> and the middle step portion <NUM>, and is more conducive to improving the dust prevention performance of the encoding assembly <NUM>. Of course, increasing the matching area between the outer cylindrical sidewall <NUM> and the middle step portion <NUM> is also conducive to increasing the reliability of the connection between the upper cover <NUM> and the base <NUM>.

In some embodiments, the base <NUM> includes an outer step portion <NUM> connected with the middle step portion <NUM>. The middle step portion <NUM> is closer to the rotating shaft <NUM> than the outer step portion <NUM> in the radial direction of the output shaft <NUM>. The thickness of the middle step portion <NUM> in the axial direction of the output shaft <NUM> is greater than that of the outer step portion <NUM> in the axial direction of the output shaft <NUM>. In other words, in case the base <NUM> includes the outer step portion <NUM>, the middle step portion <NUM> and the inner step portion <NUM>, all the outer step portion <NUM>, the middle step portion <NUM> and the inner step portion <NUM> gradually approach the rotating shaft <NUM> in the radial direction of the output shaft <NUM>, and the thickness of the base <NUM> in the axial direction of the output shaft <NUM> gradually increases. The outer step portion <NUM> may be fixed on the bracket <NUM> or the housing <NUM>, that is, the mounting hole <NUM> may be defined in the outer step portion <NUM>; the outer cylindrical sidewall <NUM> may also be arranged on the outer step portion <NUM>. Correspondingly, the encoding disk 1151A and the circuit board <NUM> may be arranged on the inner side of the outer cylindrical sidewall <NUM>.

In some embodiments, the light source <NUM> may be arranged on the middle step portion <NUM>. The side of the middle step portion <NUM> away from the encoding disk 1151A defines a mounting groove, and the light source <NUM> is arranged in the mounting groove. In other words, the light source <NUM> is arranged outside the encoding assembly <NUM>, which is conducive to simplifying the wiring of the light source <NUM>, as well as facilitating the assembly of the light source <NUM>. For the opposed optical encoders, the circuit board <NUM> may be arranged on the side of the encoding disk 1151A away from the base <NUM>, that is, the circuit board <NUM> is arranged between the encoding disk 1151A and the top cover <NUM> in the axial direction of the output shaft <NUM>. The outer diameter of the circuit board <NUM> in the radial direction of the output shaft <NUM> may be greater than the outer diameter of the encoding disc 1151A in the radial direction of the output shaft <NUM>. Furthermore, the encoding assembly <NUM> includes a plurality of supporting rods <NUM> spaced apart from each other around the rotating shaft <NUM>. For example, the quantity of supporting rods <NUM> is three, the supporting rods <NUM> are supported between the middle step portion <NUM> and the circuit board <NUM>, and are arranged outside the encoding disk 1151A. Of course, the circuit board <NUM> may also be fixed on the top cover <NUM>.

In some embodiments, the light source <NUM> may be arranged on the circuit board <NUM>, that is, the light source <NUM> and the reading head 1152A are both arranged on the circuit board <NUM>, thus forming the reflective optical encoders. In this way, the circuit board <NUM> may be arranged on the side of the encoding board 1151A away from the base <NUM>, for example being supported on the middle step portion <NUM> by the supporting rod <NUM>, or for example being fixed on the top cover <NUM>. The circuit board <NUM> may also be arranged on the side of the encoding board 1151A adjacent to the base <NUM>, for example, being fixed on the middle step section <NUM>.

Based on the above related description, in order to facilitate the setting of the wiring structure of the joint module <NUM>, the rotating shaft <NUM> communicates with the outside of the encoding assembly <NUM> after passing through the avoiding holes defined in the encoding disk 1151A, the circuit board <NUM>, and the top cover <NUM> in sequence. In this case, there is a risk that external matters (such as grinding dust generated by the friction plate <NUM> during operation) enters into encoding assembly <NUM> through the avoiding holes in the top cover <NUM> and pollutes the encoding disk 1151A. Therefore, it is necessary to improve the relevant structure to improve the dust prevention performance of the encoding assembly <NUM>.

Referring to <FIG>, the upper cover <NUM> includes an inner cylindrical sidewall <NUM> connected to the top cover <NUM>, and the inner cylindrical sidewall <NUM> and the outer cylindrical sidewall <NUM> extend in a same direction towards the same side of the top cover <NUM>. The inner cylindrical sidewall <NUM> partially extends into the rotating shaft <NUM> along the axial direction of the output shaft <NUM> to prolong the path of external matters entering the encoding assembly <NUM>, thereby increasing the dust prevention performance of the encoding assembly <NUM>. Correspondingly, the circuit board <NUM> is ring shaped and sleeves around the inner cylindrical sidewall <NUM>. Since the circuit board <NUM> and the upper cover <NUM> may be kept relatively stationary, the gap between the inner peripheral surface of the circuit board <NUM> and the outer peripheral surface of the inner cylindrical sidewall <NUM> in the radial direction of the output shaft <NUM> may be as small as possible to meet the gap requirements for the assembly of the circuit board <NUM> and the upper cover <NUM>.

In some embodiments, the depth of the inner cylindrical sidewall <NUM> inserted into the rotating shaft <NUM> in the axial direction of the output shaft <NUM> may be between <NUM> and <NUM>. The deeper the depth is (that is, the deeper the inner cylindrical sidewall <NUM> inserting into the rotating shaft <NUM> along the axial direction of the output shaft <NUM>), the more conducive to lengthening the path of external matters entering the encoding assembly <NUM>. However, since the rotating speed of the rotating shaft <NUM> may be the same as that of the output shaft <NUM>, it is also prone to cause an unnecessary collision between the rotating shaft <NUM> and the inner cylindrical sidewall <NUM>. On the contrary, the smaller the depth is (that is, the shallower the inner cylindrical sidewall <NUM> inserting into the rotating shaft <NUM> along the axial direction of the output shaft <NUM>), the more conducive to avoiding the collision between the rotating shaft <NUM> and the inner cylindrical sidewall <NUM>, but it is also prone to weaken the dust prevention performance of the encoding assembly <NUM>.

In some embodiments, the clearance between the inner cylindrical sidewall <NUM> and the rotating shaft <NUM> in the radial direction of the output shaft <NUM> may be between <NUM> and <NUM>. The smaller the clearance is, the more conducive to preventing external matters from entering the encoding assembly <NUM>, however, since the rotating speed of the rotating shaft <NUM> may be the same as that of the output shaft <NUM>, there is also a risk of existing unnecessary collision between the rotating shaft <NUM> and the inner cylindrical sidewall <NUM>. On the contrary, the larger the clearance is, the more conducive to avoiding the collision between the rotating shaft <NUM> and the inner cylindrical sidewall <NUM>, however, it is also prone to weaken the dust prevention performance of the encoding assembly <NUM>.

In some embodiments, similar to the solution of arranging the end of the rotating shaft <NUM> with a gradually changed structure, the outer diameter of the portion of the inner cylindrical sidewall <NUM> inserted into the rotating shaft <NUM> gradually decreases along the axial direction of the output shaft <NUM> and the direction away from the top cover <NUM>, to form a gradually changing structure. Correspondingly, the inner diameter of the portion of the rotating shaft <NUM> for receiving the inner cylindrical sidewall <NUM> gradually decreases along the axial direction of the output shaft <NUM> and the direction away from the top cover <NUM>, to form a gradually changed structure matched with the inner cylindrical sidewall <NUM>. In this way, compared with the columnar structure with equal diameter, the gradually changed structure is also conducive to prolong the path of external matters entering the encoding assembly <NUM>, thus increasing the dust-proof performance of the encoding assembly <NUM>.

Since the circuit board <NUM> may be arranged on the side of the encoding disk 1151A away from the base <NUM>, the orthographic projection of the circuit board <NUM> along the axial direction of the output shaft <NUM> completely covers the encoding disk 1151A, as such, if there is external matters, the external matters will fall on the circuit board <NUM> first before entering the encoding assembly <NUM>, thus prolonging the path of extemal matters falling on the encoding disk 1151A, which is also conducive to improving the dust-proof performance of the encoding assembly <NUM>, especially when the upper cover <NUM> defines an avoiding hole for wiring and does not include the inner cylindrical sidewall <NUM>.

Claim 1:
A joint module (<NUM>) of a robot arm (<NUM>), wherein the joint module (<NUM>) comprises:
a housing (<NUM>);
a driving assembly (<NUM>), comprising a lower bearing seat (<NUM>), a lower bearing (<NUM>) having an outer ring connected with the lower bearing seat (<NUM>), and an output shaft (<NUM>) connected with an inner ring of the lower bearing (<NUM>);
a speed reduction assembly (<NUM>), comprising an input shaft (<NUM>) detachably connected with the output shaft (<NUM>);
a braking assembly (<NUM>), connected with the output shaft (<NUM>);
a first fastener (<NUM>), configured to fix the lower bearing seat (<NUM>) on the housing (<NUM>); and
a second fastener (<NUM>), configured to fix the speed reduction assembly (<NUM>) on the housing (<NUM>);
the driving assembly (<NUM>) further comprises:
an upper bearing seat (<NUM>), arranged on a side of the lower bearing seat (<NUM>) opposite to the speed reduction assembly (<NUM>), and the braking assembly (<NUM>) being fixed on the upper bearing seat (<NUM>); and
an upper bearing (<NUM>), comprising an inner ring connected with the output shaft (<NUM>) and an outer ring connected with the upper bearing seat (<NUM>);
characterized in that,
the joint module (<NUM>) further comprises:
a first elastic member (<NUM>);
wherein the braking assembly (<NUM>) is configured to press the first elastic member (<NUM>) on the outer ring of the upper bearing (<NUM>);
the braking assembly (<NUM>) comprises a friction plate (<NUM>) connected with the output shaft (<NUM>), and the driving assembly (<NUM>) further comprises an adapter (<NUM>) connected with the output shaft (<NUM>);
wherein the friction plate (<NUM>) is sleeved on the adapter (<NUM>), an outer contour of the adapter (<NUM>) and an inner contour of the friction plate (<NUM>) are non-circular and matched with each other when viewed along an axial direction of the output shaft (<NUM>), to allow the friction plate (<NUM>) to rotate with the adapter (<NUM>), and allow the friction plate (<NUM>) to move relative to the adapter (<NUM>) along the axial direction of the output shaft (<NUM>).