TWI675161B - A speed reducer with inner teeth flexspline - Google Patents

Abstract

The invention discloses an internal-tooth soft-gear reducer, comprising: a planetary gear set, wherein the planetary gear set is provided with a first meshing portion and a second meshing portion; an internal gear ring, the internal gear ring and the planetary gear set A first meshing portion is connected; a flexible wheel is provided with an internal tooth portion on an inner wall of the flexible wheel, the internal tooth portion is connected with a second meshing portion of the planetary gear set; and a housing is provided with an accommodation therein. Space, the planetary gear set, the ring gear and the flexible gear are arranged in the accommodation space. The invention has higher meshing strength, can reduce the requirement of processing precision of parts, and achieve high-precision output at the same time, the preparation cost is low, the gear wear is small, and the reversibility is better.

Description

Internal-tooth soft-wheel reducer

The invention relates to the field of speed reducers, in particular to an internal-tooth soft-wheel speed reducer

The reducer plays a role in matching the speed and torque transmission between the prime mover and the working machine or the actuator. It is a relatively precise machine. Its purpose is to reduce the speed and increase the torque. It has many types, different models, and different types have different uses. Among them, planetary reducer and harmonic reducer are the commonly used types.

The planetary reducer is tightly coupled to the gear box housing by an internal gear ring. The center of the ring gear has a sun gear driven by external power. Between the two is a group of planets combined by multiple gears on the planet carrier. The gear set has an output shaft on the planet carrier. When the sun gear is driven by power, it can drive the planetary gear to rotate and revolve along the center of the track of the internal gear ring. The rotation of the planetary gear drives the output shaft to output power; especially a gear The differential planetary reducer can achieve a larger reduction ratio than the ordinary planetary reducer. It has two layers of internal gears, the number of planetary gears is A, and A is an arbitrary integer> = 2 at this time, and the planetary gears engage the two at the same time. Internal tooth, one of the ring gears is a standard tooth shape, the number of teeth is assumed to be N, and the other ring gear is a variable tooth shape, the number of teeth is N + A or NA, because the two internal gears have tooth differences, Thereby forming an output; However, it has the unavoidable defects: 1. Weak meshing strength: The inner ring gear of the variated tooth profile cannot be fully meshed with the planetary gear when it meshes with the planetary gear. It is a local contact and the number of meshing teeth is small, which results in Insufficient meshing strength reduces bearing torque; 2. Large backlash: Because the inner ring gear of the variable tooth profile cannot fully mesh with the planetary gear, it is also easy to produce a large tooth backlash. To improve the backlash, a higher backlash is required. Processing accuracy; 3. Gear wear is large: When the internal gear ring of the variated tooth meshes with the planet gear, there is rolling friction and sliding friction at the same time, which causes the gear to wear easily.

The harmonic reducer has a layer of internal ring gear, whose number of teeth is N, a wave generator whose wave number is A, and A is an arbitrary integer> = 2, an external-toothed soft gear, whose number of teeth is NA, and the wave when used The generator pushes out the outer tooth flexible gear, so that the outer teeth of the soft point of the soft gear mesh with the inner ring gear. Because there is a tooth difference between the two, the output is formed. The harmonic gear reducer has high precision and high bearing capacity. And other advantages, compared with ordinary reducers, because the material used is 50% less, its volume and weight are reduced by at least 1/3; but it has unavoidable defects: 1. Extremely high machining accuracy requirements, allow small tolerances on parts : The backlash is determined by the tightness of the meshing between the internal gear and the external teeth of the flexible gear. Therefore, the size of the internal gear, wave generator, and external teeth of the flexible gear is extremely high to achieve the effect of close meshing; 2. The larger the torque, the higher the cost of the deformed bearing: between the wave generator and the inner wall of the flexible wheel, a deformable bearing needs to be installed to reduce the friction between the wave generator and the inner wall of the flexible wheel. Simultaneously deform the deformed bearing and the flexible wheel, resulting in starting torque It is too large, and the existence of deformed bearings also increases the cost; 3. Poor reversibility: when some reverse input is required at the output end, because higher starting torque becomes higher gripping force, higher reverse is required Only torque can be input to run, it is easy to damage the gear, resulting in limited use conditions.

The technical problem to be solved by the present invention is to provide a flexible reducer with internal teeth, which has a high meshing strength, can reduce the precision requirements of parts processing and achieve high-precision output at the same time, has low preparation cost, and has less gear wear and better reversibility .

In order to solve the above technical problems, the present invention provides an internal-tooth soft-wheel 2 reducer, which includes: a planetary gear set 1, which is provided with a first meshing portion 11 and a second meshing portion 12; Ring 13, the internal ring gear 13 is connected to the first meshing portion 11 of the planetary gear set 1; a flexible wheel 2, an internal tooth portion 21 is provided on the inner wall of the flexible wheel 2, and the internal tooth portion 21 is connected to the planetary gear The second engaging portions 12 of the group 1 are connected; And an outer casing 3, an accommodation space is provided in the outer casing 3, and the inner space is provided with the inner planetary gear set 1 and the flexible wheel 2.

Further, the planetary gear set (1) includes at least two planetary power wheels 14, and the planetary power wheels 14 are meshedly connected with the inner teeth 21 of the flexible wheel 2, and the flexible wheels 2 are engaged with the planetary power wheels 14. Deformation under support.

Further, the planetary wheel set 1 further includes support wheels 15, the number of the support wheels 15 is the same as the number of the planetary power wheels 14, and the support wheels 15 are disposed between two adjacent planetary power wheels 14, The supporting wheel 15 abuts on the inner tooth portion 21 of the flexible wheel 2.

Further, a surface of the planetary power wheel 14 is provided with a first tooth portion 141 and a second tooth portion 142. A plurality of the first tooth portions 141 of the planetary power wheels 14 cooperate to form a first meshing portion 11, and The second teeth 142 of the planetary power wheels 14 cooperate to form a second meshing portion. The number of teeth of the first teeth 141 is the same as the number of teeth of the second teeth 142 or the first teeth. The number of teeth of the portion 141 is greater than the number of teeth of the second teeth portion 142 or the number of teeth of the first teeth portion 141 is smaller than the number of teeth of the second teeth portion 142.

Further, a third tooth portion 151 is provided on the surface of the support wheel 15, and the third tooth portion 151 is meshed with the inner tooth portion 21 of the flexible wheel 2.

Further, a fourth tooth portion 152 is further provided on the surface of the support wheel 15, and the fourth tooth portion 152 is meshed with the inner ring gear 13.

Further, a sun gear 4 is provided in the middle of the planetary gear set 1, the sun gear 4 is connected to a first power end 5, a second power end 6 is provided on the flexible wheel 2, and the first power end 5 is The second power end 6 is provided as a power input element and a power output element, respectively.

Further, the planetary carrier 16 of the planetary gear set 1 is connected to a first power end 5, the flexible wheel 2 is provided with a second power end 6, and the first power end 5 and the second power end 6 are respectively provided It is a power input element and a power output element.

The beneficial effects of the present invention are as follows: 1. Improving the meshing strength, the deformable internal tooth 21 tooth profile of the flexible wheel 2 can maintain the standard tooth profile, and when meshing with the planetary gear set 1, it can fully mesh, improving the meshing strength and increasing the load. Torque; 2. The backlash is small, allowing lower machining accuracy. Because the flexible wheel 2 can be deformed, it will naturally retract inwardly under the elastic stress of the material, so it can absorb the dimensional tolerance of the planetary wheel set 1. Also, since the flexible wheel 2 only meshes with the planetary gear set 1 provided inside, there is no positional accuracy problem of the external teeth of the flexible wheel 2 meshing with the internal ring gear 13, which can reduce the processing precision requirements of the parts while ensuring good output accuracy; 3. The gear wear is small. When the deformable flexible wheel 2 meshes with the planetary gear set 1, it can be regarded as the normal internal ring gear 13 meshing with the external gear to maintain rolling friction and reduce gear wear. It is small and reduces the cost of the deformed bearing. The planetary power wheel 14 is used to eject the internal toothed flexible wheel 2. The starting bearing does not need to be deformed, so the starting torque is small. At the same time, the deformed bearing is not required to reduce friction. Low cost; 5. reversible preferred, since the starting torque is small, i.e. smaller gripping force, and therefore does not require high reverse input torque can be operated, reversible increase.

Explanation of labels in the figure:

1‧‧‧ planet wheel set

11‧‧‧ the first meshing part

12‧‧‧ the second meshing part

13‧‧‧ Ring gear

14‧‧‧ planetary power wheel

141‧‧‧ first tooth

142‧‧‧Second tooth

15‧‧‧ support wheel

151‧‧‧Third Tooth

152‧‧‧Fourth Teeth

16‧‧‧ planet carrier

2‧‧‧ soft round

21‧‧‧ Internal tooth

3‧‧‧ shell

4‧‧‧ Sun Wheel

5‧‧‧First Power End

6‧‧‧Second Power End

A‧‧‧ Ring gear setting position

B‧‧‧ soft wheel setting position

In order to more clearly illustrate the technical solution in the technology of the embodiment of the present invention, the drawings used in the technical description of the embodiment will be briefly introduced below. FIG. 1 is a schematic diagram of the cooperation between the planetary gear and the flexible gear according to the first embodiment of the present invention; FIG. 2 is a schematic cross-sectional structure diagram of the planetary carrier drive according to the second embodiment of the present invention; and FIG. Schematic diagram; Figure 4 is an exploded schematic diagram of Embodiment 3 of the present invention; Figure 5 is a schematic diagram of a transmission with a support wheel in Embodiment 4 of the present invention; and Figure 6 is a support wheel with a single layer of teeth in Embodiment 4 of the present invention Fig. 7 is a schematic diagram of the transmission of a support wheel with double teeth in the fourth embodiment of the present invention; Fig. 8 is a schematic diagram of a planetary power wheel with the same number of teeth in the fifth embodiment of the present invention; and Fig. 9 is a fifth embodiment of the present invention. The first schematic diagram of a planetary power wheel with a different number of teeth; FIG. 10 is a schematic diagram of the second planetary power wheel with a different number of teeth according to the fifth embodiment of the present invention.

The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[Example 1]

Referring to FIG. 1, an embodiment of the internal-toothed soft gear reducer of the present invention includes a planetary gear set 1 and a flexible gear 2. The planetary gear set 1 is provided with a first meshing portion 11 and a second meshing portion 12. The first meshing portion 11 is connected to the inner ring gear 13 of the planetary gear set 1, and the planetary gear set 1 meshes and rotates within the inner ring gear 13. The inner tooth portion 21 is provided on the inner wall of the flexible wheel 2, and the inner tooth portion 21 and the second The meshing portion 12 is connected, and the flexible wheel 2 meshes and rotates on the outer periphery of the planetary gear set 1. At this time, the first layer of deceleration is formed between the planetary gear set 1 and the ring gear 13, that is, the planetary deceleration, and the flexible gear 2 and the planetary gear set 1 A second layer of deceleration is formed between them, because the number of teeth of the internal tooth portion 21 of the flexible wheel 2 is not the same as the number of teeth of the internal ring gear 13, so the differential speed reduction is performed, and the planetary gear set 1 and the internal ring gear 13 cooperate with the flexible wheel 2 A combined deceleration effect is formed later; after setting the internal tooth portion 21 on the inner wall of the flexible wheel 2, the internal tooth portion 21 directly meshes with the planetary gear set 1, so that the tooth shape of the internal tooth portion 21 can maintain the standard tooth shape, and When the planetary gear set 1 is engaged, it can be completely engaged, which increases the meshing strength and increases the bearing torque. When the planetary gear set 1 is rotated in the fully meshed state, It is considered that the normal ring gear meshes with the gear to maintain rolling friction and reduce gear wear; and based on the elasticity of the flexible wheel 2 that can be deformed, the internal tooth portion 21 provided on the inner wall will naturally mesh inwardly, so it can absorb The dimensional tolerance of the planetary gear set 1, and because the flexible gear 2 only meshes with the internally arranged planetary gear set 1, there is no problem in the positional accuracy of the external teeth of the flexible gear 2 and the internal ring gear 13, which can reduce the precision requirements of parts processing. At the same time, it guarantees good output accuracy, achieves the effect of small backlash and allows lower processing accuracy.

The planetary wheel set 1 includes at least two planetary power wheels 14. The deformation of the flexible wheel 2 is obtained by the support of the planetary power wheel 14. At this time, the planetary power wheel 14 is on the long axis after the flexible wheel 2 is deformed, and the planetary power wheel The outer teeth of 14 are meshed with the inner teeth 21 of the flexible wheel 2. When the planetary power wheel 14 rotates, the flexible wheel 2 can be driven to rotate; therefore, only the flexible wheel 2 needs to be deformed at startup, and the starting torque is small. Without the need for deformed bearings to reduce friction, It can reduce costs; and because the starting torque is small, that is, the gripping force is small, it does not require too high reverse input torque to run, and the reversibility is improved and the reversibility is better.

The above-mentioned planetary gear set 1, the ring gear 13 and the flexible wheel 2 may be disposed in an accommodation space in the casing 3 to form an effective relative position fixation. The casing 3 here may also be a bracket or the like.

[Example 2]

In an embodiment, referring to FIG. 2, the sun gear 4 can also be eliminated, and the planetary carrier 16 of the planetary gear set 1 can be connected to the first power end 5. The flexible power wheel 2 is provided with the second power end 6. A power end 5 can be a power input element, that is, an input shaft, which is directly fixedly connected to the planet carrier 16, the input shaft rotates the planet carrier 16, and the second power end 6 is a power output element, and the power input element inputs power After that, the planet carrier 16 drives the planetary power wheel 14 to perform revolutions. The planetary power wheel 14 and the ring gear 13 mesh with each other to rotate at the same time. After the planetary power wheel 14 rotates, the flexible wheel 2 is driven to rotate. In this embodiment, Because there is no sun gear 4, it can reduce the tooth processing accuracy and tooth wear caused by one layer of meshing, and can effectively reduce the part processing accuracy requirements, while ensuring good output accuracy. When there is no male gear 4 in the above structure, its reduction ratio = the difference between the number of teeth of the internal gear of the flexible gear / the number of teeth of the internal gear of the flexible gear and the number of internal ring gear teeth.

[Example 3]

In an implementation, referring to FIG. 3 and FIG. 4, a planetary gear set 1 is provided with a sun gear 4 in the middle, the sun gear 4 is connected to the first power end 5, and the flexible wheel 2 is provided with a second power end 6. The first power end 5 may be a power input element, and the second power end 6 may be a power output element. After the power input element inputs power, the sun gear 4 rotates, that is, it is formed in cooperation with the planetary gear set 1, the ring gear 13 and the flexible gear 2. Effective tooth difference planetary deceleration, the flexible wheel 2 is output through the power output element; the above planetary reduction ratio = (the number of internal ring gear teeth / the number of male gear) +1

Tooth difference reduction ratio = (the difference between the number of internal teeth of the flexible gear / the number of internal teeth of the flexible gear and the number of internal ring gears)

The combined reduction ratio = planetary reduction ratio * tooth difference reduction ratio takes the number of teeth of the ring gear 13 as 80, the number of teeth of the planet gear 30, the number of teeth of the sun gear 4 as 20, and the number of teeth of the internal gear 21 of the flexible wheel 2 as 78 as examples: The above planetary reduction ratio = (80/20) + 1 = 5

Tooth difference reduction ratio = 78 / (78-80) =-39, negative sign means reverse rotation

Combined reduction ratio = 5 * -39 = -195, negative sign means reverse rotation

[Example 4]

In an embodiment, referring to FIG. 5, the planetary wheel set 1 further includes support wheels 15. The number of support wheels 15 is the same as the number of planetary power wheels 14. The support wheels 15 are disposed on two adjacent planetary power wheels. Between 14, the supporting wheel 15 is abutted on the inner tooth portion 21 of the flexible wheel 2. A in the figure indicates the setting position of the ring gear and B indicates the setting position of the flexible wheel; the supporting wheel 15 can keep the flexible wheel 2 against Tight, the tooth meshing degree is high, there is no tooth loss phenomenon; the support wheel 15 is arranged on the planet carrier 16 and rotates with the planet carrier 16, that is, the revolution movement, and the support wheel 15 is in contact with the flexible wheel 2 in the When the flexible wheel 2 is rotated, the support wheel 15 is frictionally rotated to form self-rotation.

Wherein, referring to FIG. 6, a third tooth portion 151 may be further provided on the surface of the support wheel 15. The third tooth portion 151 is meshed with the inner tooth portion 21 of the flexible wheel 2. After being connected by tooth meshing, The friction between the support wheel 15 and the flexible wheel 2 is greatly reduced, and the flexible wheel 2 rotates more smoothly.

Referring to FIG. 7, a fourth tooth portion 152 may be further provided on the surface of the support wheel 15. The fourth tooth portion 152 is meshed with the ring gear 13. During operation, the support wheel 15 and the ring gear 13 are simultaneously engaged. It meshes with the inner tooth portion 21 of the flexible wheel 2 and has a good running correction function, and has higher stability during rotation.

[Example 5]

In one embodiment, the planetary power wheel 14 is provided with a first tooth portion 141 and a second tooth portion 142 on the surface. The first tooth portions 141 of the plurality of planetary power wheels 14 cooperate to form the first meshing portion 11. The second tooth portion 142 of the planetary power wheel 14 cooperates to form the second meshing portion 12. Referring to FIG. 8, the number of teeth of the first tooth portion 141 may be the same as the number of teeth of the second tooth portion 142. Consistent, so the number of teeth of the ring gear 13 corresponding to the first meshing portion 11 (that is, the number of 13 teeth of the first ring gear) is the same as the number of teeth of the ring gear 13 corresponding to the second meshing portion 12 (that is, the number of 13 teeth of the second ring gear) Because the flexible wheel 2 is used in this application, the ring gear 13 in the second layer is an analog component); Referring to FIG. 9, the number of teeth of the first tooth portion 141 may be greater than the number of teeth of the second tooth portion 142; its tooth reduction ratio can have a wider range of variation; refer to FIG. 10 The number of teeth of the first tooth portion 141 may be smaller than the number of teeth of the second tooth portion 142; the tooth difference reduction ratio can have a wider range of variation; the above-mentioned planetary power wheel 14 can be changed according to the change of the sun gear 4 And the change, the randomness of preparation increases, and the scope of application is also greatly improved. Moreover, when the structure described in the present application is used for preparation, due to the design of the flexible wheel 2 provided with the internal teeth, the assembly parts of the reducer are reduced, and the reducer can be assembled from pure plastic parts, which greatly reduces the manufacturing cost.

The above embodiments are merely preferred examples for fully explaining the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art on the basis of the present invention are all within the protection scope of the present invention. The protection scope of the present invention shall be defined by the scope of the patent application.

Claims (8)

An internal-tooth soft-gear reducer is characterized in that it comprises: a planetary gear set (1), the planetary gear set (1) is provided with a first meshing portion (11) and a second meshing portion (12); 13), the inner ring gear (13) is connected to the first meshing portion (11) of the planetary gear set (1); a flexible wheel (2), an inner tooth portion (2) is provided on an inner wall of the flexible wheel (2) 21), the internal tooth portion (21) is connected to the second meshing portion (12) of the planetary gear set (1); and a housing (3), the housing (3) is provided with an accommodation space, and the planet The wheel set (1) and the flexible wheel (2) are arranged in the accommodation space. The internal-tooth soft gear reducer according to item 1 of the scope of the patent application, wherein the planetary gear set (1) includes at least two planetary power wheels (14), and the planetary power wheels (14) and The internal tooth part (21) of the wheel (2) is meshed and connected, and the flexible wheel (2) is deformed under the meshing support of the planetary power wheel (14). The internal-tooth flexible reducer according to item 2 of the scope of the patent application, wherein the planetary gear set (1) further includes support wheels (15), and the number of the support wheels (15) and the planetary power wheels The number of (14) is the same. The support wheel (15) is disposed between two adjacent planetary power wheels (14), and the support wheel (15) is abutted on the inner teeth of the flexible wheel (2). (21) on. The internal-tooth soft gear reducer according to item 2 of the scope of the patent application, wherein the surface of the planetary power wheel (14) is provided with a first tooth portion (141) and a second tooth portion (142), The first tooth portions (141) of the plurality of planetary power wheels (14) cooperate to form a first meshing portion (11), and the second tooth portions (142) of the plurality of planetary power wheels (14) cooperate to form The second engaging portion (12), the number of teeth of the first tooth portion (141) is consistent with the number of teeth of the second tooth portion (142), or the number of teeth of the first tooth portion (141) is greater than The number of teeth of the second tooth portion (142) or the number of teeth of the first tooth portion (141) is smaller than the number of teeth of the second tooth portion (142). The internal-tooth flexible reducer according to item 3 of the scope of the patent application, wherein a surface of the support wheel (15) is provided with a third tooth portion (151), and the third tooth portion (151) It is in mesh connection with the internal tooth part (21) of the flexible wheel (2). The internal-tooth soft gear reducer according to item 5 of the scope of patent application, wherein A fourth tooth portion (152) is further provided on the surface of the support wheel (15), and the fourth tooth portion (152) is meshed with the inner ring gear (13). The internal-tooth soft gear reducer according to any one of claims 1 to 6, wherein the planetary gear set (1) is provided with a male gear (4), and the male gear (4) Connected to the first power end (5), the flexible wheel (2) is provided with a second power end (6), and the first power end (5) and the second power end (6) are respectively set as power input Components and power output components. The internal-tooth soft-wheel reducer according to any one of claims 1 to 6, wherein the planet carrier (16) of the planetary gear set (1) is connected to a first power end (5), A second power end (6) is provided on the flexible wheel (2), and the first power end (5) and the second power end (6) are respectively configured as a power input element and a power output element.