CN116914992A

CN116914992A - Servo deceleration module with overload protection function and overload protection method

Info

Publication number: CN116914992A
Application number: CN202310937144.9A
Authority: CN
Inventors: 吴迪; 张�杰; 戴一帆; 李伟; 张继洋
Original assignee: Nanjing Kemaide Robot Technology Co ltd
Current assignee: Nanjing Kemaide Robot Technology Co ltd
Priority date: 2023-07-28
Filing date: 2023-07-28
Publication date: 2023-10-20
Anticipated expiration: 2043-07-28
Also published as: CN117895719A; CN117895719B; CN116914992B

Abstract

The invention provides a servo speed reduction module with an overload protection function and an overload protection method thereof, comprising a harmonic speed reducer, a servo motor, a sealing end cover, an encoder and a cable assembly; the harmonic reducer, the servo motor, the sealing end cover, the encoder and the cable assembly are sequentially installed along the axial direction; the rotor bracket of the servo motor is arranged on the wave generator, and a locker is arranged between the rotor bracket and the wave generator; the motor shell and the flexible gear of the harmonic reducer are fixedly and hermetically arranged; the rotor support is in a rotationally fixed connection with the wave generator when the lock is in the first position, and the rotor support is in a rotationally fixed connection with the wave generator when the lock is in the second position. The invention can realize the purpose of overload protection; since the lock is provided between the rotor holder and the wave generator and the number of parts is small, the axial dimension of the entire module is not increased, and thus miniaturization and weight saving of the module can be achieved.

Description

Servo deceleration module with overload protection function and overload protection method

Technical Field

The invention belongs to the technical field of speed reducers, and particularly relates to a servo speed reduction module with an overload protection function and an overload protection method.

Background

The harmonic reducer has the advantages of high reduction ratio, high precision, small volume, high torque capacity and the like, and can be manufactured into a power module with small volume by matching with a servo motor. However, when the motor is used, the load suddenly increases to cause overload of the motor, and the motor needs to be disconnected in time to avoid burning out the overload.

The chinese patent with application number 202111073052.8 discloses a harmonic reducer, when the control unit obtains that the real-time current of motor is greater than predetermine maximum current value, the control unit immediately controls the clutch to switch to the off-state from the connected state, and output shaft and load connection pad disconnection, the output shaft takes place idle running and can't transmit the moment of torsion to the load connection pad, and the load connection pad loses power input and can't continue to rotate thereby in time avoid collision to continue to take place, has faster response speed, has effectively guaranteed cooperator's safety, prevents simultaneously that the harmonic reducer from destroying the inefficacy. However, this structure is complicated, and the control program needs to be reprogrammed, so that the axial dimension of the whole module is also significantly increased, which is not beneficial to the development of the module in the direction of miniaturization and light weight.

Disclosure of Invention

The invention aims to provide a servo speed reduction module with an overload protection function, which adopts a locker capable of automatically shifting under the action of a rotor bracket to realize the purpose of cutting off the power transmission of the rotor bracket and a wave generator so as to avoid overload, and can also realize heat dissipation of a motor by utilizing the continuous rotation of the rotor bracket on the basis.

In order to achieve the above purpose, the present invention provides the following technical solutions: a servo speed reduction module with an overload protection function comprises a harmonic speed reducer, a servo motor, a sealing end cover, an encoder and a cable assembly;

the harmonic reducer, the servo motor, the sealing end cover, the encoder and the cable assembly are sequentially installed along the axial direction;

the rotor bracket of the servo motor is arranged on the wave generator, and a locker is arranged between the rotor bracket and the wave generator; the motor shell and the flexible gear of the harmonic reducer are fixedly and hermetically arranged;

the lock has a first position in which the rotor support is in anti-torque connection with the wave generator and a second position in which the rotor support is disconnected from the wave generator;

when the load value of the wave generator exceeds a preset value, the locker is in the second position under the action of the rotor bracket, and when the load value of the wave generator does not exceed the preset value, the locker is in the first position under the action of the locker.

Further, the harmonic reducer further comprises a first shell, a second shell and a bearing gland, wherein the first shell is positioned at one end far away from the servo motor, the second shell is fixedly installed with the motor shell, and the bearing gland is installed on the second shell; the first shell is fixedly arranged with the rigid gear, and the second shell is fixedly arranged with the flexible gear; the wave generator is connected with the second shell through a first bearing, and the bearing gland is abutted against the outer ring of the first bearing;

the wave generator is close to the end face of one end of the first shell and forms dynamic seal installation with the first shell, the outer circular face of the wave generator and the inner circular face of the bearing gland form dynamic seal installation, the outer circular face of the wave generator close to one end of the encoder and the inner circular face of the sealing end cover form dynamic seal installation, and therefore a speed reducer cavity, a motor cavity and an encoder cavity are all closed independent cavities.

Further, blades are arranged on two sides of the rotor support, and the wave generator is provided with an oil duct extending along the axial direction, an installation cavity for installing the locking device and communicating with the oil duct, an oil port extending along the radial direction and respectively communicating with the oil duct and the speed reducer cavity, and an oil groove extending along the axial direction and respectively communicating with the installation cavity and the motor cavity; the oil port is internally provided with a first one-way valve for preventing cooling oil from flowing from the oil duct to the speed reducer cavity, the second shell is provided with an oil hole for communicating the speed reducer cavity and the motor cavity, and the oil hole is internally provided with a second one-way valve for preventing cooling oil from flowing from the speed reducer cavity to the motor cavity;

when the locker is at the first position, the oil groove and the oil duct are closed by the locker; when the lock is in the second position, the oil groove and the oil passage are communicated by the lock.

Further, the servo motor further comprises a piston and a piston spring, wherein the piston is provided with an annular curved surface which is alternately fluctuated and arranged towards one side of the rotor bracket, a sealing ring arranged towards one side of the bearing end cover and mounting holes penetrating through the surfaces of the two sides; the piston is sleeved on the wave generator in a sliding way, the outer circular surface of the piston forms dynamic seal with the inner circular surface of the motor casing, and the inner circular surface of the sealing ring forms dynamic seal with the outer circular surface of the bearing end cover; the piston spring is arranged between the piston and the bearing end cover/the second shell, the rotor bracket is provided with a contact which is in sliding contact with the annular curved surface, and a third one-way valve which prevents cooling oil from flowing from a cavity at the side of the motor cavity to a cavity at the opposite side of the motor cavity is arranged in the mounting hole;

the wave generator is provided with an oil duct extending along the axial direction, an installation cavity for installing the locker and communicating with the oil duct, an oil port extending along the radial direction and respectively communicating with the oil duct and the speed reducer cavity, and an oil groove extending along the axial direction and respectively communicating with the installation cavity and the motor cavity; a first one-way valve for preventing cooling oil from flowing from the speed reducer cavity to the oil duct is arranged in the oil port, and the second shell is provided with an oil hole for communicating the speed reducer cavity and a cavity at the opposite side;

Further, the outer circular surface of the rotor support is provided with a spiral groove, and the spiral groove is communicated with the oil groove.

Further, the locker comprises a locking piece, a locking spring and a rubber sealing cover;

the top of the locking piece is provided with a spherical head, and a central hole extending along the axial direction and penetrating through two ends and a side hole penetrating through the side wall and the central hole along the radial direction are arranged in the locking piece; the outer circular surface of the rotor bracket is provided with a spherical groove matched with the spherical head;

the locking spring abutting the ball head to cause the locking member to have a tendency to be in the first position; the rubber sealing cover is arranged at the bottom of the locking piece in a sealing way;

when the spherical head is positioned in the spherical groove, the locking piece is positioned at the first position, the side hole is positioned in the mounting cavity, and the rubber sealing cover seals the joint of the mounting cavity and the oil duct;

when the spherical head is separated from the spherical groove, the locking piece is positioned at the second position, the side hole is positioned in the oil duct, and the rubber sealing cover is communicated with the joint of the mounting cavity and the oil duct.

Further, the dynamic seal is a non-contact seal formed by a labyrinth seal structure.

Further, a movable disk of the encoder is mounted on the wave generator, and a stationary disk thereof is mounted on the sealing end cover;

the cable assembly comprises a cable end cover, a cable and a waterproof joint; the waterproof connector is arranged on the cable end cover; the cable end cover is fixedly arranged in the sealing end cover, the center of the cable end cover extends along the axial direction to form a hollow pipe section, and the hollow pipe section sequentially penetrates through the static disc, the movable disc and the wave generator.

The invention also provides a servo deceleration module overload protection method, which comprises the following steps:

a locker is arranged between a rotor bracket of the servo motor and a wave generator of the harmonic reducer;

setting the lock to be capable of being changed from a first position to a second position after receiving a force exceeding a preset force;

when the rotating force generated by the servo motor acts on the locker through the rotor bracket, if the acting force exceeds the preset force, the rotor bracket rotates relative to the wave generator, otherwise, the rotor bracket drives the wave generator to rotate.

Further, after the locking device is in the second position, cooling oil circulation flow is formed between the motor cavity of the servo motor and the speed reducer cavity of the harmonic speed reducer along with the relative rotation of the rotor support relative to the wave generator.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention sets the locker between the rotor bracket and the wave generator, and plays different roles according to the position condition of the locker, namely, the locker plays a key role when being positioned at the first position, so as to realize the connection of the rotor bracket and the wave generator; when the lock is at the second position, the connection is disconnected, so that the overload protection function is realized; since the lock is provided between the rotor holder and the wave generator and the number of parts is small, the axial dimension of the entire module is not increased, and thus miniaturization and weight saving of the module can be achieved.

2. The invention conducts the oil duct after the displacement by means of the valve action of the locker, and the driving force generated by the continuous rotation of the rotor bracket after the power transmission is disconnected enables the cooling oil to circulate in the motor cavity and the speed reducer cavity, thereby realizing the conduction of heat to the speed reducer cavity and the heat dissipation of the servo motor.

3. The invention adopts non-contact sealing as a dynamic sealing means, and can avoid friction heat generation caused by sealing by adopting a sealing ring.

4. The middle hole threading pipe and the encoder cover are integrated, and the fixed arrangement is not rotated any more, so that friction between a cable passing through the middle hole threading pipe and the middle hole threading pipe is avoided.

5. The cable component adopts the sealing plastic terminal for outgoing lines, so that the volume is reduced and the cost is reduced while the sealing performance is ensured.

Drawings

FIG. 1 is a perspective view of a first embodiment of the present invention;

FIG. 2 is a front elevational view of the first embodiment of FIG. 1;

FIG. 3 is a cross-sectional view of the structure taken along the direction A-A in FIG. 2;

FIG. 4 is an enlarged view of a portion of FIG. 3 at I;

FIG. 5 is a schematic view of coolant flow with the corresponding lock of FIG. 4 in a second position;

FIG. 6 is an enlarged view of a portion of FIG. 3 at II;

FIG. 7 is a schematic view of coolant flow with the second check valve of FIG. 6 in an on state;

FIG. 8 is an enlarged view of a portion of III in FIG. 3;

FIG. 9 is a schematic view of coolant flow with the first check valve of FIG. 8 in an on state;

FIG. 10 is a cross-sectional view showing the construction of a harmonic reducer according to the first embodiment;

FIG. 11 is a structural cross-sectional view of a cable assembly according to the first embodiment;

FIG. 12 is an enlarged view of a portion of an embodiment of the present invention between a second harmonic reducer and a servo motor;

FIG. 13 is a perspective view of the piston of the embodiment of FIG. 12;

FIG. 14 is a schematic view of coolant flow with the corresponding piston of FIG. 12 in a forward position;

fig. 15 is a schematic view of the coolant flow with the corresponding piston of fig. 12 in the aft position.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Example 1

As shown in fig. 1 to 10, the present embodiment discloses a servo deceleration module with an overload protection function, which includes a harmonic reducer 1, a servo motor 2, a seal end cover 3, an encoder 4, and a cable assembly 5. For convenience of description, in this example, the harmonic reducer 1, the servo motor 2, the seal end cover 3, the encoder 4 and the cable assembly 5 are sequentially installed from front to back along the axial direction with the position of the harmonic reducer 1 being the front and the position of the cable assembly 5 being the rear. The specific composition and structure of each component are described as follows:

the harmonic reducer 1 includes a first housing 102, a rigid gear 104, a compliant bearing 104, a first bearing 109, a second bearing 101, a bearing end cap 108, a cross bearing 105, a wave generator 110, a compliant gear 106, and a second housing 107.

The first shell 102, the rigid gear 104, the cross bearing 105, the flexible gear 106, the second shell 107 and the bearing end cover 108 are sequentially arranged from front to back, wherein the inner rings of the first shell 102, the rigid gear 104 and the cross bearing 105 are fixedly connected through screws.

The outer ring of the cross bearing 105, the flange portion of the flexspline 106, and the second housing 107 are fixedly connected by screws, and the bearing cap 108 is fixedly mounted on the rear end face of the second housing 107 by screws. The cylindrical portion of the flexspline 106 extends forward and the teeth on the outer circular surface thereof mesh with the teeth on the inner circular surface of the rigid spline 104.

The wave generator 110 is disposed throughout the entire harmonic reducer 1 and its rear end protrudes out of the second housing 107. The wave generator 100 is a shaft-like member of a hollow structure, and the wave generator 110 is sequentially divided into a wave generation section, a middle section and an input shaft section according to the different right-front-rear directions of the connection members. The wave generation section is rotatably mounted with the inner circular surface of the first housing 102 through the second bearing 101, is rotatably mounted with the portion of the cylindrical portion of the flexspline 106 engaged with the rigid spline 104 through the flexspline 103, and is dynamically sealed with the rear end surface of the first housing 102. The front section of the intermediate section forms a rotational mounting with the second housing 107 via the first bearing 109, and the rear section forms a dynamic sealing mounting with the inner circular surface of the bearing end cap 107, the bearing end cap 107 having a forwardly projecting annular abutment which abuts against the outer ring of the first bearing 109.

The servo motor 2 includes a motor case 201, a stator bracket 202, and a rotor bracket 203. The motor case 201 is fixedly mounted to the second housing 107 by screws. The stator bracket 202 is fixedly installed inside the motor casing 201, and the rotor bracket 203 is sleeved on the input shaft section of the wave generator 110. The seal end cover 3 is fixedly mounted at the rear end of the motor case 201 by screws. The front inner circular surface of the sealing end cover 3 forms a dynamic sealing installation with the input shaft section, and the rear inner circular surface of the sealing end cover forms a rotating installation with the input shaft section through a third bearing 302.

The rotor support 203 and the input shaft section are connected in a disconnectable anti-torsion manner, i.e. a locking device 6 is arranged between the rotor support 203 and the input shaft section, and the locking device 6 is configured to disconnect the anti-torsion connection between the rotor support 203 and the input shaft section after a certain condition is reached, and to maintain the anti-torsion connection between the rotor support 203 and the input shaft section before a condition is not reached. Specifically, the input shaft section is provided with a mounting cavity 110c, and the lock 6 is mounted in the mounting cavity 110 c. The lock 6 includes a lock 601 and a lock spring 602. The locking member 601 has a spherical head on top and the outer circumferential surface of the rotor holder 102 is provided with a spherical groove 102a matching the spherical head.

It is known that the lock 6 may be provided in plurality and distributed uniformly in the circumferential direction. When the load does not exceed the set value, the locking member 601 is in the first position, and due to the action of the locking spring 602, the spherical head of the locking member 601 can be inserted into the spherical groove 102a on the rotor support 102, so as to provide anti-torsion connection force between the rotor support 102 and the wave generator 110, and at the moment, the rotating force generated by the servo motor 2 can act on the wave generator 110, so that the harmonic reducer 1 is driven to work, and the purpose of reducing output is achieved. When the load exceeds the set value, the axial component force generated by the acting force of the rotating force on the spherical head of the locking piece 601 exceeds the elastic force of the locking spring 602, so that the locking piece 601 is driven to move to the second position along the axial direction, at the moment, the spherical head is completely separated from the spherical groove 102a, the connection between the rotor support 102 and the wave generator 110 is disconnected, at the moment, the rotating force generated by the servo motor 2 cannot act on the wave generator 110 and only can idle the rotor support 102, and thus overload of the rotor support 102 is avoided. It can be appreciated that the magnitude of the set value is related to the magnitude of the elastic force of the locking spring 602, and the specific value is determined according to the actual model selection calculation of the locking spring 602, and the calculation manner thereof belongs to the prior art, so that details are not repeated herein.

The encoder 4 includes a movable disk 402, a stationary disk 401, and a movable disk holder 403. A movable disk bracket 403 is mounted at the end of the input shaft section of the wave generator 110 by a screw, a movable disk 402 is mounted on the movable disk bracket 403, and a stationary disk 401 is mounted on the seal end cover 3 behind the movable disk 402. After the distance between the mounting surface of the static disc 401 on the sealing end cover 301 and the end surface of the input shaft section of the wave generator 110 is compared with the required distance, the axial positions of the static disc 401 and the moving disc 402 are finely adjusted through adjusting gaskets of different specifications and numbers, and the axial distance between the static disc 401 and the moving disc 402 is ensured.

As shown in fig. 11, the cable assembly 5 includes a cable end cap 501, a cable 502, and a waterproof joint 503. The cable end cover 501 is fixedly mounted on the seal end cover 3 by a screw, and the center of the cable end cover extends along the axial direction to form a hollow pipe section 501a, and the hollow pipe section 501a sequentially penetrates through the static disc 401, the dynamic disc 402 and the wave generator 110. The cable 502 is divided into an encoder cable 502b and a power cable 205, and a waterproof joint 503 is mounted on the cable end cover 501 and provided in two. One end of the encoder cable 502b is connected with the static disc 401 through a connecting terminal 502a, and the other end penetrates through and is fastened to the waterproof joint 503 to be thrown out of the module, so that the waterproof terminal 502c is pressed. The ground wire of the power cable 205 is fixed on the sealing end cover 3 through a screw, and the tail end of the ground wire passes through the other waterproof connector 503 and is thrown out of the module to be pressed against the waterproof terminal 504. Since the cable end cap 501 is fixedly provided, the cable 502 is relatively stationary with respect to the hollow tube segment 501a after passing through the hollow tube segment 501a to be connected with an external device, and thus friction does not occur.

When the lock 6 is in the second position, the servomotor 2 does not drive the wave generator 110 to rotate, but the servomotor 2 is still in the energized state, and the heating value is increased relative to the normal operation, so that the servomotor 2 is obviously heated. The harmonic reducer 1 has no electronic component, so the heat resistance is far greater than that of the servo motor 2, and in order to prevent the servo motor 2 from continuously heating up to cause demagnetization, lubricating oil added into the motor cavity 2a and the reducer cavity 1a is used as cooling oil for heat transfer, so that the temperature of the servo motor 2 is reduced. The principle of the device is that the heat generated by the servo motor 2 is conducted to the harmonic reducer 1 by utilizing the circulating flow of lubricating oil in the two chambers, and the heat is dissipated outwards by means of the heat conduction capability of the metal part of the harmonic reducer 1, so that the device can avoid the overhigh temperature of the servo motor 2 before the servo motor is stopped, and the heating condition is relieved. The specific mode is as follows:

since the relevant components are mounted in a dynamic seal manner, the speed reducer chamber 1a, the motor chamber 2a and the encoder chamber 4a are all closed independent chambers. The encoder cavity 4a is isolated from the motor cavity 2a, and lubricating oil is filled in the motor cavity 2a and the speed reducer cavity 1a, and the lubricating oil has insulativity and can conduct heat.

As shown in fig. 4 to 9, both sides of the rotor bracket 102 are provided with blades 102a, and the wave generator 110 has an oil passage 110b extending in the axial direction, an oil port 110a extending in the radial direction and communicating with the oil passage 110b and the speed reducer chamber 1a, respectively, and an oil groove 110d extending in the axial direction and communicating with the installation chamber 110c and the motor chamber 2a, respectively. The oil passage 110b, the oil port 110a, and the oil groove 110d are provided in equal numbers to the lock 6 and are uniformly distributed in the circumferential direction. The front end of the oil passage 110b communicates with the installation cavity 110 c. The oil port 110a is provided with a first check valve 8 for preventing the flow of cooling oil from the oil passage 110b to the speed reducer chamber 1a, the second housing 107 is provided with an oil hole 107a for communicating the speed reducer chamber 1a and the motor chamber 2a, and the oil hole 107a is provided with a second check valve 7 for preventing the flow of cooling oil from the speed reducer chamber 1a to the motor chamber 2a.

The locker 6 further includes a rubber sealing cover 603 having a central hole 601a extending in an axial direction and penetrating both ends and a side hole 601b penetrating a sidewall and the central hole 601a in a radial direction inside the locking member 601, and the rubber sealing cover 603 is installed at a bottom of the locking member 601.

When the locking piece 601 is at the first position, the side hole 601b of the locking piece 601 is located in the mounting cavity 110c, the rubber sealing cover 603 seals the joint of the mounting cavity 110c and the oil duct 110b, at this time, the oil groove 110d and the oil duct 110b are sealed by the locking piece 601, and lubricating oil cannot flow in the two cavities. When the load increases so that the rotor holder 102 drives the locking piece 601 to be in the second position, the side hole 601b is located in the oil passage 110b, and the oil groove 110d, the center hole 601a, the side hole 601b, and the oil passage 110b communicate.

As shown in fig. 5, 7 and 9, when the load is increased to the second position where the locking member 601 is driven to the second position, the oil groove 110d, the central hole 601a, the side hole 601b and the oil duct 110b are communicated, at this time, the rotor bracket 102 is still rotated, and under the action of the blades 102a on both sides of the rotor bracket, the lubricating oil in the motor cavity 2a pushes the steel ball 701 in the second one-way valve 7 against the action of the spring 702 to enable the lubricating oil to flow from the motor cavity 2a to the speed reducer cavity 1a, so that the lubricating oil in the speed reducer cavity 1a pushes the steel ball 801 in the first one-way valve 8 against the action of the spring 802 to enable the lubricating oil to flow from the speed reducer cavity 1a to the motor cavity 2a, and in this process, the lubricating oil transmits heat generated by the servo motor 2 to the harmonic speed reducer 1 to enable the harmonic reducer 1 to assist in heat dissipation.

In this example, the seal between the stationary members is a seal ring, and the dynamic seal between the movable members and between the stationary members and the movable members is a non-contact seal formed by a labyrinth seal structure. Three concentric annular grooves 110e are formed in the end face of the wave generation section, three concentric convex rings 102b are formed in the inner end face of the first housing 102, and each concentric convex ring 102b is located in one concentric annular groove 110e at a corresponding radial position, so that labyrinth seal is formed. The inner circular surface of the bearing cap 108 is also provided with sealing grooves 108a, which also form labyrinth seals with the outer circular surface of the intermediate section of the wave generator 110. The inner circular surface of the sealing end cover 3 is provided with three grooves 301a which form labyrinth seal with the outer circular surface of the input shaft section, and can also adopt a sealing ring for contact seal.

Example two

One difference from the embodiment is that the source of the circulating power of the lubricating oil in this embodiment is different. Specifically, as shown in fig. 12 to 15, the servo motor 2 further includes a piston 204 and a piston spring 205, the piston 204 having alternately undulating annular curved surfaces 204a provided toward one side of the rotor holder 203, a seal ring 204c provided toward one side of the bearing cap 108, and mounting holes 204b penetrating both side surfaces. The piston 204 is slidably fitted over the input shaft section of the wave generator 110 in a spline structure so as to axially move in the motor chamber 2a on the front side of the rotor bracket 203. The outer circular surface of the piston 204 and the inner circular surface of the motor casing 201 form dynamic seal installation, and the inner circular surface of the sealing ring 204c and the outer circular surface of the bearing end cover 108 form dynamic seal installation.

The piston spring 205 is disposed between the piston 204 and the bearing cap 108, the rotor holder 203 has contacts 203b that make sliding contact with the annular curved surface 204a, and the number of the contacts 203b is identical to the number of undulations of the annular curved surface 204a, in this example, the contacts 203b are disposed four, and are uniformly distributed in the circumferential direction, and similarly, the number of undulations of the annular curved surface 204a is four. Thus, when the rotor holder 203 rotates one turn, the piston 204 reciprocates four times in the axial direction. That is, the greater the number of undulations, the greater the number of reciprocations that the piston 204 completes during one revolution of the rotor support 203. The dynamic seal in this example is a non-contact seal formed by a labyrinth seal structure, that is, the outer circular surface of the piston 204 is provided with three grooves, which form a labyrinth seal with the inner circular surface of the motor casing 201, and the inner circular surface is provided with three grooves, which form a labyrinth seal with the outer circular surface corresponding to the bearing end cover 108.

A third check valve 9 is installed in the installation hole 204b to prevent the cooling oil from flowing from the side chamber of the motor chamber 2a to the opposite side chamber. The oil port 110a is fitted with a first check valve 8 that prevents the flow of cooling oil from the speed reducer chamber 1a to the oil passage 110b, and the second housing 107 is provided with an oil hole 107a that communicates the speed reducer chamber 1a with the opposite side chamber.

When the lock 6 is in the first position, the oil groove 110d and the oil passage 110b are closed by the lock 6. When the lock 6 is in the second position, the oil groove 110d and the oil passage 110b are communicated by the lock 6. In order to enable the lubricating oil to flow into the motor chamber 2a more smoothly, the outer circumferential surface of the rotor holder 203 is provided with a spiral groove 203a, and the spiral groove 203a communicates with the oil groove 110d.

As shown in fig. 14 and 15, after the locking member 601 is in the second position, the rotor holder 203 continues to rotate, and the piston 204 is driven to reciprocate in the axial direction by the sliding fit between the contact 203b and the annular curved surface 204a, so that the lubricant in the speed reducer chamber 1a is pumped into the motor chamber 2a, and then returns to the speed reducer chamber 1a through the oil passage 110b to form periodic pump oil, thereby realizing the circulation flow of the lubricant.

It is understood that in the second embodiment, the axial dimensions of the wave generator 110 and the motor housing 201 are increased to provide a space for mounting the piston 204 in the motor chamber 2a, and the structure is not changed. As the axial dimension of the motor housing 201 increases, the axial dimension of the entire module increases accordingly, but the overall axial dimension is also significantly smaller than in the case of an overload protection scheme using a friction clutch.

a lock 6 is provided between the rotor holder 203 of the servo motor 2 and the wave generator 110 of the harmonic reducer 1.

The setting locker 6 is capable of being shifted from the first position to the second position upon receiving a force exceeding a preset force;

when a rotational force generated by the servo motor 2 acts on the locker 6 through the rotor holder 203, if the acting force exceeds a preset force, the rotor holder 203 rotates relative to the wave generator 110, otherwise the rotor holder 203 rotates the wave generator 110.

When the lock 6 is in the second position, the rotor holder 203 rotates relative to the wave generator 110, and the lubricant circulates between the motor chamber 2a of the servo motor 2 and the reducer chamber 1a of the harmonic reducer 1.

The present invention is not described in detail, but is well known to those skilled in the art, and is not described in detail.

In the description of the present invention, it should be understood that the terms "upper," "lower," "left," "right," and the like indicate an orientation or a positional relationship based on that shown in the drawings, and are merely for convenience of description and for simplifying the description, and do not indicate or imply that the apparatus or element in question must have a specific orientation, as well as a specific orientation configuration and operation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature.

In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more. In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

Finally, what is to be described is: the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the examples, it should be understood by those skilled in the art that modifications and equivalents may be made thereto without departing from the spirit and scope of the technical solution of the present invention, which is intended to be covered by the scope of the claims of the present invention.

Claims

1. The utility model provides a servo deceleration module with overload protection function, includes harmonic reducer (1), servo motor (2), seal end cover (3), encoder (4) and cable subassembly (5), its characterized in that:

the harmonic reducer (1), the servo motor (2), the sealing end cover (3), the encoder (4) and the cable assembly (5) are sequentially installed along the axial direction;

a rotor bracket (203) of the servo motor (2) is arranged on the wave generator (110), and a locker (6) is arranged between the rotor bracket and the wave generator; the motor shell (201) is fixedly and hermetically arranged with the flexible gear (106) of the harmonic reducer (1);

the lock (6) has a first position in which the rotor support (203) is in a rotationally fixed connection with the wave generator (110) and a second position in which the rotor support (203) is disconnected from the wave generator (110);

when the load value of the wave generator (110) exceeds a preset value, the locker (6) is in the second position under the action of the rotor bracket (203), and when the load value of the wave generator (110) does not exceed the preset value, the locker (6) is in the first position under the action of the locker.

2. The servo deceleration module with overload protection function according to claim 1, wherein: the harmonic reducer (1) further comprises a first shell (102) positioned at one end far away from the servo motor (2), a second shell (107) fixedly installed with the motor shell (201) and a bearing gland (108) installed on the second shell (107); the first shell (102) is fixedly arranged with the rigid wheel (104), and the second shell (107) is fixedly arranged with the flexible wheel (106); the wave generator (110) is connected with the second shell (107) through a first bearing (109), and the bearing gland (108) is abutted against the outer ring of the first bearing (109);

the wave generator (110) is close to the end face of one end of the first shell (102) and forms dynamic seal installation between the first shell (102), the outer circular face of the wave generator is in dynamic seal installation with the inner circular face of the bearing gland (108), the outer circular face of the wave generator close to one end of the encoder (4) and the inner circular face of the sealing end cover (3) form dynamic seal installation, and therefore a speed reducer cavity (1 a), a motor cavity (2 a) and the encoder cavity (4 a) are all closed independent cavities.

3. The servo deceleration module with overload protection function according to claim 2, wherein:

the rotor support (102) is provided with blades (102 a) on two sides, the wave generator (110) is provided with an oil duct (110 b) extending along the axial direction, a mounting cavity (110 c) for mounting the locking device (6) and communicating with the oil duct (110 b), an oil port (110 a) extending along the radial direction and respectively communicating with the oil duct (110 b) and a speed reducer cavity (1 a), and an oil groove (110 d) extending along the axial direction and respectively communicating with the mounting cavity (110 c) and a motor cavity (2 a); a first one-way valve (8) for preventing cooling oil from flowing from the oil duct (110 b) to the speed reducer cavity (1 a) is arranged in the oil port (110 a), an oil hole (107 a) for communicating the speed reducer cavity (1 a) with the motor cavity (2 a) is arranged in the second shell (107), and a second one-way valve (7) for preventing cooling oil from flowing from the speed reducer cavity (1 a) to the motor cavity (2 a) is arranged in the oil hole (107 a);

-the oil groove (110 d) and the oil channel (110 b) are closed by the lock (6) when the lock (6) is in the first position; when the lock (6) is in the second position, the oil groove (110 d) and the oil passage (110 b) are communicated by the lock (6).

4. The servo deceleration module with overload protection function according to claim 2, wherein: the servo motor (2) further comprises a piston (204) and a piston spring (205), wherein the piston (204) is provided with an alternately undulating annular curved surface (204 a) arranged towards one side of the rotor support (203), a sealing ring (204 c) arranged towards one side of the bearing end cover (108) and mounting holes (204 b) penetrating through two side surfaces; the piston (204) is sleeved on the wave generator (110) in a sliding way, the outer circular surface of the piston forms dynamic seal with the inner circular surface of the motor casing (201), and the inner circular surface of the sealing ring (204 c) forms dynamic seal with the outer circular surface of the bearing end cover (108); the piston spring (205) is arranged between the piston (204) and the bearing end cover (108)/the second shell (107), the rotor bracket (203) is provided with a contact (203 b) which is in sliding contact with the annular curved surface (204 a), and a third one-way valve (9) which prevents cooling oil from flowing from a side cavity of the motor cavity (2 a) to the opposite side cavity is arranged in the mounting hole (204 b);

the wave generator (110) is provided with an oil duct (110 b) extending along the axial direction, a mounting cavity (110 c) for mounting the locking device (6) and communicating with the oil duct (110 b), an oil port (110 a) extending along the radial direction and respectively communicating with the oil duct (110 b) and a speed reducer cavity (1 a), and an oil groove (110 d) extending along the axial direction and respectively communicating with the mounting cavity (110 c) and a motor cavity (2 a); a first one-way valve (8) for preventing cooling oil from flowing from the speed reducer cavity (1 a) to the oil duct (110 b) is arranged in the oil port (110 a), and an oil hole (107 a) for communicating the speed reducer cavity (1 a) with the cavity at the opposite side is arranged in the second shell (107);

5. The servo deceleration module with overload protection as claimed in claim 4, wherein: the outer circular surface of the rotor support (203) is provided with a spiral groove (203 a), and the spiral groove (203 a) is communicated with the oil groove (110 d).

6. The servo deceleration module with overload protection according to claim 3 or 4, wherein: the locker (6) comprises a locking piece (601), a locking spring (602) and a rubber sealing cover (603);

the top of the locking piece (601) is provided with a spherical head, and a central hole (601 a) extending along the axial direction and penetrating through two ends and a side hole (601 b) penetrating through the side wall and the central hole (601 a) along the radial direction are arranged in the locking piece; the outer circular surface of the rotor bracket (102) is provided with a spherical groove (102 a) matched with the spherical head;

-the locking spring (602) abutting the spherical head to cause the locking member (601) to have a tendency to be in the first position; the rubber sealing cover (603) is arranged at the bottom of the locking piece (601) in a sealing way;

when the spherical head is positioned in the spherical groove (102 a), the locking piece (601) is positioned at the first position, the side hole (601 b) is positioned in the mounting cavity (110 c) and the rubber sealing cover (603) seals the joint of the mounting cavity (110 c) and the oil duct (110 b);

when the spherical head is separated from the spherical groove (102 a), the locking piece (601) is in the second position, the side hole (601 b) is positioned in the oil duct (110 b), and the rubber sealing cover (603) is communicated with the connecting part of the mounting cavity (110 c) and the oil duct (110 b).

7. A servo deceleration module with overload protection according to any one of claims 2 to 5, wherein:

the dynamic seal is a non-contact seal formed by a labyrinth seal structure.

8. A servo deceleration module with overload protection according to any one of claims 2 to 5, wherein: a movable disc (402) of the encoder (4) is arranged on the wave generator (110), and a static disc (401) of the encoder is arranged on the sealing end cover (3);

the cable assembly (5) comprises a cable end cover (501), a cable (502) and a waterproof joint (503); the waterproof connector (503) is arranged on the cable end cover (501); the cable end cover (501) is fixedly arranged in the sealing end cover (3), the center of the cable end cover extends along the axial direction to form a hollow pipe section (501 a), and the hollow pipe section (501 a) sequentially penetrates through the static disc (401), the movable disc (402) and the wave generator (110).

9. A servo deceleration module overload protection method is characterized in that: the method comprises the following steps:

a locker (6) is arranged between a rotor bracket (203) of the servo motor (2) and a wave generator (110) of the harmonic reducer (1);

-providing said lock (6) capable of being transformed from a first position to a second position upon receiving a force exceeding a preset force;

when the rotating force generated by the servo motor (2) acts on the locker (6) through the rotor support (203), if the acting force exceeds the preset force, the rotor support (203) rotates relative to the wave generator (110), otherwise, the rotor support (203) drives the wave generator (110) to rotate.

10. The overload protection method of a servo deceleration module according to claim 9, wherein: after the locking device (6) is in the second position, cooling oil circulation flow is formed between the motor cavity (2 a) of the servo motor (2) and the speed reducer cavity (1 a) of the harmonic speed reducer (1) along with the relative rotation of the rotor support (203) relative to the wave generator (110).