Harmonic reducer flexspline, harmonic reducer and wheel hub motor

Abstract

The utility model discloses a kind of harmonic reducer flexspline, including rigid ring, elastic reset piece and multiple independent tooth parts, the middle part of the rigid ring has the center hole through both sides, the side wall of the rigid ring is evenly provided with multiple installation grooves through inside and outside around its own center, the tooth part is set in the installation groove one by one, the elastic reset piece is set on the rigid ring and provides the elastic force that makes the tooth part retract into the installation groove.The utility model has the advantages of small processing difficulty, large rigidity and strength, long service life.

Description

Technical Field

[0001] This utility model relates to a harmonic reducer, and more particularly to a harmonic reducer flex wheel, a harmonic reducer, and a hub motor. Background Technology

[0002] Currently, hub motors on the market generally use planetary gears for speed reduction. The internal gear ring is fixedly connected to the hub housing or connected to the hub housing via a one-way clutch. The sun gear is fixed to the rotor or shaft. The planetary gears mesh with the internal gear ring and the sun gear, respectively, and a fixed planetary gear support is used, thus achieving speed reduction for the hub housing. Harmonic reducers used in other industries typically consist of a flexible gear (intermediate gear), a steel wheel (an internal gear ring fixed inside the housing), and a wave generator. The wave generator is fixed to the motor shaft, the steel wheel is fixed to the housing, and the flexible gear is fixed to a fixed shaft or motor end cover. The flexible gear is a flexible rubber gear ring. Through contact between the wave generator's protrusion and the flexible gear, the non-contact area of ​​the wave generator disengages from the flexible gear, and the flexible gear simultaneously disengages from the steel wheel. The contact point of the flexible gear is supported, changing from a perfectly round shape before contact to a deformed wave shape during contact. This causes the wave area to mesh with the internal teeth of the steel wheel, thereby driving the steel wheel to rotate.

[0003] However, the main drawbacks of the above two types of reducers are: 1. The planetary gear structure of the former scheme often suffers from failures such as gear fatigue, tooth root fracture, and tooth surface pitting, which affects the service life. It also has high meshing noise during operation, complex tooth profile, high machining difficulty, and high manufacturing cost.

[0004] 2. The latter scheme of harmonic reducer structure, because the flexible wheel material is a flexible non-metallic material, after the flexible wheel bears a large alternating load, the fatigue strength of the flexible wheel material is poor and it is easy to break and fail. The manufacturing process of the flexible wheel is complicated and it is difficult to achieve the stiffness and strength of steel against steel, resulting in a short service life. Utility Model Content

[0005] The purpose of this invention is to provide a harmonic reducer flexspline that is easy to process, has high rigidity and strength, and a long service life.

[0006] Another objective of this invention is to provide a harmonic reducer that is easy to manufacture, has high rigidity and strength, and a long service life.

[0007] The third objective of this invention is to provide a hub motor that has the advantages of stable operation and long service life.

[0008] To achieve the above objectives, the harmonic reducer flexure provided by this utility model includes a rigid ring, an elastic reset member, and multiple independent teeth. The rigid ring has a central hole that passes through both sides in the middle. The sidewall of the rigid ring is uniformly provided with multiple mounting grooves that pass through the inner and outer sides around its own center. The teeth are correspondingly arranged in the mounting grooves. The elastic reset member is arranged on the rigid ring and provides an elastic force that causes the teeth to retract into the mounting grooves. Compared with existing technologies, this invention uses a rigid ring with multiple mounting grooves evenly distributed around its center on the sidewall. Teeth are then positioned one-to-one within these grooves, and the elastic force of a resilient resetting element retracts the teeth into the grooves. When the wave generator is installed in the center hole of the rigid ring, its rotation causes the teeth to be pushed out of the grooves and engage with the teeth of the rigid wheel. The teeth then automatically retract into the grooves, forming a harmonic pattern that drives the rigid wheel to rotate slowly. This design avoids the use of traditional flexible structures for the flex wheel. Throughout the drive process, the rigid ring and teeth of the flex wheel remain undeformed, resulting in high rigidity and strength, significantly improving the output torque of the harmonic reducer. Furthermore, it is easier to manufacture, has a longer service life, and effectively improves the operational stability of the harmonic reducer.

[0009] Preferably, the outer wall of the rigid ring is provided with an annular groove around its center, and the elastic restoring element is a closed-loop spring, which is housed within the annular groove. This allows for the use of only one closed-loop spring to provide elastic restoring force to all teeth on the rigid ring, thus greatly simplifying the structure of the flexible wheel.

[0010] Specifically, the toothed part is provided with a receiving groove, and the closed-loop spring passes through the receiving groove and presses against the toothed part. By providing the receiving groove, the closed-loop spring can pass through to provide elastic force to the toothed part without affecting the operation of the toothed part, making the structure compact and reasonable.

[0011] Specifically, the toothed part includes a tooth, a connecting part, and a pressing part. One end of the connecting part is connected to the tooth, and the other end of the connecting part is connected to the pressing part. The tooth extends into the mounting groove, and the pressing part is located in the central hole.

[0012] Specifically, the mounting groove includes a first groove and a second groove communicating with the first groove. The first groove penetrates the outer side of the rigid ring, and the second groove penetrates the inner side of the rigid ring. The gear teeth are accommodated in the first groove, and the connecting portion is accommodated in the second groove.

[0013] Specifically, the width of the radial cross-section of the first groove is greater than the width of the radial cross-section of the second groove; the width of the gear teeth is greater than the width of the radial cross-section of the second groove; and the width of the connecting portion is greater than the width of the radial cross-section of the second groove. This prevents the teeth from disengaging from the mounting groove, ensuring operational stability. Specifically, the pressing part has a first end and a second end, both of which are provided with an arc surface that contacts and engages with the roller of the wave generator. By providing the arc surface, when the roller makes frontal pressing contact with one of the teeth, the roller gradually disengages from the arc surface of the second end of the previous tooth and gradually contacts the arc surface of the first end of the next tooth, thereby causing the teeth to continuously extend out of the rigid ring.

[0014] A harmonic reducer includes a wave generator, a rigid wheel, and a flexible wheel. The wave generator is coaxially disposed within the central hole of the flexible wheel and rotates relative to the rigid wheel around a central axis. The rigid wheel is coaxially disposed outside the flexible wheel. The inner sidewall of the rigid wheel is provided with a rim, and the rim is uniformly provided with a plurality of toothed grooves around its center circumferentially, the number of toothed grooves being greater than the number of teeth. The end of the wave generator has a roller, which presses against the teeth in sequence as the wave generator rotates, causing the teeth of the teeth to extend out of the mounting groove and engage with the toothed grooves, thereby driving the rigid wheel to rotate.

[0015] Preferably, the number of grooves is at least three more than the number of teeth.

[0016] A hub motor includes a hub end cover, a hub housing, a front half-shaft, a rear half-shaft, a clutch assembly, an inner rotor motor, and a harmonic reducer. The hub end cover and the hub housing are connected to form a motor cavity. The front half-shaft is pivotally connected to the hub end cover. The inner rotor motor and the harmonic reducer are respectively disposed within the motor cavity. The output shaft of the inner rotor motor is connected to the wave generator of the harmonic reducer. The rigid wheel of the harmonic reducer is fixedly connected to the hub end cover. The flexible wheel of the harmonic reducer is connected to the rear cover of the inner rotor motor. One end of the rear half-shaft is connected to the flexible wheel, and the other end rotatably extends out of the hub housing. The clutch assembly is disposed between the rear half-shaft and the hub housing. The output shaft of the inner rotor motor drives the wave generator, which in turn drives the rigid wheel through the flexible wheel, causing the rigid wheel to rotate the hub housing. Attached Figure Description

[0017] Figure 1 This is a perspective view of the flex wheel of the harmonic reducer of this utility model.

[0018] Figure 2This is a radial sectional view of the flexure of the harmonic reducer of this utility model.

[0019] Figure 3 This is a perspective view of the rigid ring of the flexible wheel in the harmonic reducer of this utility model.

[0020] Figure 4 This is a perspective view of the teeth of the flexspline of the harmonic reducer of this utility model.

[0021] Figure 5 This is a radial sectional view of the rigid ring of the flexure of the harmonic reducer of this utility model.

[0022] Figure 6 This is a perspective view of the harmonic reducer of this utility model.

[0023] Figure 7 This is a radial sectional view of the harmonic reducer of this utility model.

[0024] Figure 8 yes Figure 7 Enlarged view of part A in the middle.

[0025] Figure 9 This is a three-dimensional view of the combination of the flex wheel and wave generator in the harmonic reducer of this utility model.

[0026] Figure 10 This is a radial cross-sectional view of the combination of the flex wheel and wave generator in the harmonic reducer of this utility model.

[0027] Figure 11 This is a perspective view of the wave generator of the harmonic reducer of this utility model.

[0028] Figure 12 This is a side view of the hub motor of this utility model.

[0029] Figure 13 This is an axial sectional view of the hub motor of this utility model. Detailed Implementation

[0030] To explain in detail the technical content, structural features, objectives and effects of this utility model, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0031] Please see Figure 1 and Figure 2The harmonic reducer flexure 1 of this utility model includes a rigid ring 11, an elastic reset member 12, and a plurality of independent teeth 13. The rigid ring 11 is made of steel and has a central hole 111 through both sides in the middle. The sidewall of the rigid ring 11 is uniformly provided with a plurality of mounting grooves 112 that penetrate the inner and outer sides around its center. The teeth 13 are correspondingly arranged in the mounting grooves 112. The elastic reset member 12 is disposed on the rigid ring 11 and provides an elastic force that causes the teeth 13 to retract into the mounting grooves 112. Please see Figure 2 and Figure 3 The outer wall of the rigid ring 11 is provided with an annular groove 113 around its center. The annular groove 113 is recessed downwards and passes through and connects to the mounting groove 112. The elastic reset member 12 is a closed-loop spring, i.e., it has a circular ring structure. The closed-loop spring is housed in the annular groove 113, and the outer diameter of the closed-loop spring is smaller than the diameter of the annular groove 113, so that the closed-loop spring can maintain a certain elastic force within the annular groove 113. By setting the closed-loop spring, only one closed-loop spring is needed to provide elastic reset force for all the teeth 13 on the rigid ring 11, thereby greatly simplifying the structure of the flexible wheel 1.

[0032] For example Figure 2 and Figure 4As shown, the tooth 13 is provided with a receiving groove 13a, which extends through both sides of the tooth 13 and has an opening at its upper side. The closed-loop spring passes through the receiving groove 13a and presses against the tooth 13. By providing the receiving groove 13a, the closed-loop spring can pass through to provide elastic force to the tooth 13 without affecting its operation, resulting in a compact and reasonable structure. Specifically, the tooth 13 includes a tooth 131, a connecting part 132, and a pressing part 133. The receiving groove 13a is provided on the tooth 131 and located in the middle of the tooth 131, dividing the tooth 131 into two symmetrical parts. One end of the connecting part 132 is connected to one end of the tooth 131, and the other end of the connecting part 132 is connected to the pressing part 133. The gear tooth 131 extends into the mounting groove 112, and the pressing part 133 is located in the central hole 111. The gear tooth 131, the connecting part 132, and the pressing part 133 are integrally formed. The pressing part 133 has a first end 133a and a second end 133b, both of which are provided with arc surfaces that contact and cooperate with the roller of the wave generator 2. By providing the arc surfaces, when the roller makes frontal pressing contact with one of the teeth 13, the roller gradually disengages from the arc surface of the second end 133b of the previous tooth 13 and gradually contacts the arc surface of the first end 133a of the next tooth 13, thereby causing the tooth 13 to continuously extend out of the rigid ring 11.

[0033] Please see Figure 2 , Figure 3 and Figure 5 The mounting groove 112 includes a first groove 112a and a second groove 112b communicating with the first groove 112a. The first groove 112a penetrates the outer side of the rigid ring 11, and the second groove 112b penetrates the inner side of the rigid ring 11. The gear tooth 131 is accommodated in the first groove 112a, and the connecting portion 132 is accommodated in the second groove 112b. Specifically, the width of the radial cross-section of the first groove 112a is greater than the width of the radial cross-section of the second groove 112b; the width of the gear tooth 131 is greater than the width of the radial cross-section of the second groove 112b; and the width of the connecting portion 132 is greater than the width of the radial cross-section of the second groove 112b. This prevents the tooth 131 from disengaging from the mounting groove 112, ensuring operational stability. Please see Figures 6 to 10This utility model also discloses a harmonic reducer 100, which includes a harmonic reducer flexure 1, a wave generator 2, and a rigid wheel 3 (hereinafter referred to as the flexure). The wave generator 2 is coaxially disposed in the central hole 111 of the flexure 1 and rotates relative to the rigid ring 11 around the central axis. The rigid wheel 3 is coaxially disposed outside the flexure 1. The inner sidewall of the rigid wheel 3 is provided with a wheel rim 31. The wheel rim 31 is uniformly provided with a plurality of tooth grooves 311 around the center circumference. The number of tooth grooves 311 is greater than the number of teeth 13; specifically, the number of tooth grooves 311 is up to three more than the number of teeth 13. The end of the wave generator 2 has a roller 22. As the wave generator 2 rotates, the roller 22 presses against the teeth 13 in sequence, so that the teeth 131 of the teeth 13 extend out of the mounting groove 112 and engage with the tooth grooves 311, thereby driving the rigid wheel 3 to rotate. In this embodiment, there are 51 mounting slots 112 and 51 teeth 13, and 54 tooth grooves 311. This allows one of the 51 teeth 13 to mesh with one of the 54 tooth grooves 311, with the front tooth 13 facing the front tooth wall 311a of the front tooth groove 311. Similarly, the rear tooth 13 disengages from the tooth groove 311 along the rear tooth wall 311b of the rear tooth groove 311. Therefore, by rotating the wave generator 2 and sequentially pressing against the teeth 13, the teeth 13 can sequentially press against the front tooth wall 311a of the front tooth groove 311, thereby driving the rigid wheel 3 to rotate slowly.

[0034] Please see Figure 11 The wave generator 2 includes a foot bracket 21 and a roller 22. The foot bracket 21 rotates around the central axis of the harmonic reducer flexure 1. The roller 22 is pivotally connected to the other end of the foot bracket 21, and the roller 22 can push the tooth 13 out of the mounting groove 112. Specifically, the number of feet of the foot bracket 21 is equal to the difference between the number of grooves 311 and the number of teeth 13, that is, at least 3. In this embodiment, the difference between the number of grooves 311 and the number of teeth 13 is 3. Therefore, the foot bracket 21 has 3 feet, which are evenly distributed circumferentially around its central axis. Each foot is pivotally connected to a roller 22, allowing the three rollers 22 of the wave generator 2 to simultaneously press against the three teeth 13 of the harmonic reducer flexure 1. This enables the three teeth 13, evenly distributed along the circumference of the rigid ring 11, to simultaneously mesh with the three grooves 311 of the rim 31. Therefore, the harmonic reducer flexure 1 has three driving points to drive the rim 31 to rotate, increasing torque and improving operational stability. The rollers 22 can also be replaced by bearings.

[0035] The working principle of the harmonic reducer 100 of this utility model is as follows: First, the wave generator 2 rotates, driving the roller 22 to revolve within the inner hole of the rigid ring 11. The roller 22 sequentially presses against the toothed portion 13, thereby pushing the teeth 131 of the toothed portion 13 out of the mounting groove 112. The teeth 131 extend into the tooth groove 311 of the rigid wheel 3, thus abutting against the front tooth wall of the tooth groove 311. When the toothed portion 13 continuously pushes the corresponding tooth groove 311, it can drive the rigid wheel 3 to rotate.

[0036] Compared with the prior art, this utility model sets up a rigid ring 11, and evenly provides multiple mounting grooves 112 penetrating the inner and outer sides around the center of the side wall of the rigid ring 11. Then, the teeth 13 are correspondingly set in the mounting grooves 112. The elastic force of the elastic reset member 12 is used to retract the teeth 13 into the mounting grooves 112. Therefore, when the wave generator 2 is installed in the center hole 111 of the rigid ring 11, as the wave generator 2 rotates, the teeth 13 can be pushed by the wave generator 2 in sequence, so that the teeth 13 can extend out of the mounting grooves 112 in sequence to mesh with the tooth grooves 311 of the rigid wheel 3, and then automatically retract into the mounting grooves 112 to form a harmonic shape, thereby achieving the purpose of driving the rigid wheel 3 to rotate slowly. This allows the flex wheel to avoid using a traditional flexible structure. During the entire driving process, the rigid ring 11 and the teeth 13 of the flex wheel will not deform. It has high stiffness and strength, which greatly improves the output torque of the harmonic reducer 100. It is also easy to manufacture and has a long service life, thereby effectively improving the operational stability of the harmonic reducer 100.

[0037] Please refer to the attached figures above. Figure 12 and Figure 13This utility model also discloses a hub motor 1000, including a harmonic reducer 100, a hub end cover 200, a hub housing 300, a front half-shaft 400, a rear half-shaft 500, a clutch assembly 600, and an inner rotor motor 700. The hub end cover 200 and the hub housing 300 are connected to form a motor cavity 800, and the front half-shaft 400 is pivotally connected to the hub end cover 200. The inner rotor motor 700 and the harmonic reducer 100 are respectively disposed in the motor cavity 800, and the output shaft 701 of the inner rotor motor 700 is connected to the harmonic reducer 100. The wave generator 2 of the harmonic reducer 100 is coaxially connected, and the rigid wheel 3 of the harmonic reducer 100 is fixedly connected to the hub end cover 200. The rigid ring 11 of the flexible wheel 1 of the harmonic reducer 100 has a recessed hole 113, which is connected to the protrusion of the rear cover 702 of the inner rotor motor 700 to prevent the flexible wheel 1 from rotating circumferentially. One end of the rear half-shaft 500 is connected to the flexible wheel 1, and the other end rotatably extends out of the hub housing 300. The clutch assembly 600 is disposed between the rear half-shaft 500 and the hub housing 300. The front half-shaft 400, the output end of the inner rotor motor 700, and the rear half-shaft 500 are coaxially arranged. The output shaft 701 of the inner rotor motor 700 drives the wave generator 2, which in turn drives the rigid wheel 3 through the teeth 13 of the flexible wheel 1, causing the rigid wheel 3 to rotate the hub housing 300.

[0038] The working principle of the harmonic reducer 100 of this utility model is as follows: First, the front half-shaft 400 and the rear half-shaft 500 are installed and fixed. Then, the inner rotor motor 700 is started. The output shaft of the inner rotor motor 700 rotates, driving the wave generator 2 to rotate. The wave generator 2 drives the roller 22 to revolve within the flexible wheel 1. The roller 22 sequentially presses against the toothed portion 13, causing the toothed portion 13 to extend out of the mounting groove 112. The teeth 131 of the toothed portion 13 abut against the front tooth wall of the tooth groove 311, thereby pushing the rigid wheel 3 to rotate. The rigid wheel 3 drives the hub housing 300 to rotate.

[0039] The above-disclosed embodiments are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of the present utility model. Therefore, any equivalent variations made in accordance with the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A harmonic reducer flexspline, characterized in that: It includes a rigid ring, an elastic reset member, and multiple independent teeth. The rigid ring has a central hole that passes through both sides in the middle. The sidewalls of the rigid ring are evenly provided with multiple mounting grooves that pass through the inner and outer sides around its center. The teeth are correspondingly arranged in the mounting grooves. The elastic reset member is arranged on the rigid ring and provides an elastic force that causes the teeth to retract into the mounting grooves.

2. The harmonic reducer flexspline according to claim 1, characterized in that: The outer wall of the rigid ring is provided with an annular groove around its center, and the elastic reset member is a closed-loop spring, which is housed in the annular groove.

3. The harmonic reducer flexspline according to claim 2, characterized in that: The toothed part is provided with a receiving groove, and the closed-loop spring passes through the receiving groove and presses against the toothed part.

4. The harmonic reducer flexspline according to claim 3, characterized in that: The toothed part includes a tooth, a connecting part, and a pressing part. One end of the connecting part is connected to the tooth, and the other end of the connecting part is connected to the pressing part. The tooth extends into the mounting groove, and the pressing part is located in the central hole.

5. The harmonic reducer flexspline according to claim 4, characterized in that: The mounting groove includes a first groove and a second groove communicating with the first groove. The first groove penetrates the outer side of the rigid ring, and the second groove penetrates the inner side of the rigid ring. The gear teeth are accommodated in the first groove, and the connecting portion is accommodated in the second groove.

6. The harmonic reducer flexspline according to claim 5, characterized in that: The width of the radial cross-section of the first groove is greater than the width of the radial cross-section of the second groove; the width of the gear tooth is greater than the width of the radial cross-section of the second groove; and the width of the connecting portion is greater than the width of the radial cross-section of the second groove.

7. The harmonic reducer flexspline according to claim 4, characterized in that: The pressing part has a first end and a second end, and both the first end and the second end are provided with an arc surface that contacts and cooperates with the roller of the wave generator.

8. A harmonic reducer, characterized in that: The device includes a wave generator, a rigid wheel, and a flexible wheel as described in any one of claims 1 to 7. The wave generator is coaxially disposed within the central hole of the flexible wheel and rotates relative to the rigid ring around the central axis. The rigid wheel is coaxially disposed outside the flexible wheel. The inner sidewall of the rigid wheel is provided with a rim, and the rim is uniformly provided with a plurality of toothed grooves around the center circumferentially, the number of toothed grooves being greater than the number of teeth. The end of the wave generator has a roller, and the roller presses against the teeth in sequence as the wave generator rotates, causing the teeth of the teeth to extend out of the mounting groove and engage with the toothed grooves, thereby driving the rigid wheel to rotate.

9. The harmonic reducer according to claim 8, characterized in that: The number of grooves is at least three more than the number of teeth.

10. A hub motor, characterized in that: The device includes a hub end cover, a hub housing, a front half-shaft, a rear half-shaft, a clutch assembly, an inner rotor motor, and a harmonic reducer as described in any one of claims 8 to 9. The hub end cover and the hub housing are connected to form a motor cavity, and the front half-shaft is pivotally connected to the hub end cover. The inner rotor motor and the harmonic reducer are respectively disposed in the motor cavity. The output shaft of the inner rotor motor is connected to the wave generator of the harmonic reducer. The rigid wheel of the harmonic reducer is fixedly connected to the hub end cover. The flexible wheel of the harmonic reducer is connected to the rear cover of the inner rotor motor. One end of the rear half-shaft is connected to the flexible wheel, and the other end extends rotatably out of the hub housing. The clutch assembly is disposed between the rear half-shaft and the hub housing; the output shaft of the inner rotor motor drives the wave generator, which in turn drives the rigid wheel through the flexible wheel, causing the rigid wheel to rotate the hub housing.

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