CN211852719U

CN211852719U - Harmonic speed reducer

Info

Publication number: CN211852719U
Application number: CN202020305676.2U
Authority: CN
Inventors: 林钧伟; 王哲鸿; 蔡佳吟
Original assignee: Hiwin Technologies Corp
Current assignee: Hiwin Technologies Corp
Priority date: 2020-03-12
Filing date: 2020-03-12
Publication date: 2020-11-03
Anticipated expiration: 2030-03-12

Abstract

The utility model provides a harmonic speed reducer machine, it includes a rigidity internal gear ring, outer tooth cup of a flexibility and a wave generator, the flexibility external gear cup is located rigidity internal gear ring and local joggle joint each other, the wave generator has a bearing of locating in the outer tooth cup of flexibility, a locate cam ring in the bearing and a shaft coupling of connecting the cam ring, clearance definition between the outer peripheral face of the interior anchor ring of cam ring and shaft coupling is G, be equipped with a plurality of elastic element between the outer global of anchor ring and shaft coupling within the cam ring, elastic element's tensile elastic modulus definition is K, 0.1 is K is less than or equal to 0.5, elastic element's diameter definition is D, the three satisfies 0 and is less than or equal to G and is less than or equal to the relational expression that KD. Through the deformable characteristic of the elastic element, the structural abrasion of related parts can be reduced, and the effects of automatically aligning and improving the operation precision are achieved.

Description

Harmonic speed reducer

Technical Field

The present invention relates to harmonic reducers, and more particularly to a harmonic reducer capable of eliminating running clearances.

Background

A harmonic reducer is a reduction device having a high reduction ratio. The conventional arrangement includes a rigid inner toothed ring, a flexible outer toothed cup disposed within the rigid inner toothed ring, and a wave generator disposed within the flexible outer toothed cup. When the coupling of the wave generator is driven by the power source, the elliptical wheel of the wave generator is synchronously driven to rotate, and then the flexible outer tooth cup is pushed by the elliptical wheel to become elliptical, so that the rigid inner tooth ring and the flexible outer tooth cup can be completely meshed at the long axis of the elliptical wheel and completely separated at the short axis of the elliptical wheel. Because there is a difference in the number of teeth between the rigid inner ring and the flexible outer cup, when the wave generator continues to rotate, the difference in the number of teeth can achieve the effect of high reduction ratio, thereby generating high torque output.

The harmonic reducer disclosed in taiwan patent No. I571573 is formed by assembling a coupling and an elliptical wheel together through an adapter plate, wherein two opposite side surfaces of the adapter plate are respectively provided with two first convex portions and two second convex portions, and one side surface of the elliptical wheel facing the adapter plate is provided with two first concave portions, and a chassis portion of the coupling is provided with two second concave portions. Therefore, the elliptical wheel is connected with the two first convex parts of the adapter plate in a clamping mode through the two first concave parts, and the coupler is connected with the two second convex parts of the adapter plate in a clamping mode through the two second concave parts, so that the assembly between the coupler and the elliptical wheel is completed.

However, in the above patent documents, the gap between the concave portion and the convex portion which are fitted to each other is easily increased by contact wear, and if the gap is increased, not only the operation noise is easily generated, but also the service life is also affected. In order to solve the problem of the gap, the machining accuracy must be improved, but if the requirement for the machining accuracy is high, the manufacturing cost is increased. Therefore, the above patent document has room for improvement in structure.

In addition, the harmonic reducer disclosed in japanese patent application laid-open No. 2019-039547 has a spring and a ball disposed between the input shaft and the elliptical wheel, and when the torque force applied to the input shaft is too large, the elliptical wheel slides relative to the input shaft, thereby preventing the damage of related parts.

SUMMERY OF THE UTILITY MODEL

A primary object of the present invention is to provide a harmonic reducer that can eliminate running clearances to reduce structural wear and improve the accuracy of operation.

In order to achieve the above objective, the harmonic reducer of the present invention comprises a rigid inner ring gear, a flexible outer cup gear, a wave generator, and a plurality of elastic elements. The flexible outer tooth cup is arranged in the rigid inner tooth ring and is partially meshed with the rigid inner tooth ring; the wave generator is provided with a bearing, a cam ring and a coupler, the bearing is arranged in the flexible outer tooth cup, the cam ring is arranged in the bearing, the inner ring surface of the cam ring is provided with a plurality of first concave parts, the coupler is arranged in the cam ring in a penetrating mode, and the outer peripheral surface of the coupler is provided with a plurality of second concave parts; each elastic element is arranged between the first concave part of the cam ring and the second concave part of the coupler, a gap between the inner ring surface of the cam ring and the outer peripheral surface of the coupler is defined as G, the tensile elastic rate of the elastic element is defined as K, the diameter of the elastic element is defined as D, and the three satisfy the following relation: g is more than or equal to 0 and less than or equal to KD, wherein K is more than or equal to 0.1 and less than or equal to 0.5.

Therefore, when the coupler is driven by a power source, the cam ring is driven to rotate together, and then the flexible outer tooth cup is pushed by the cam ring to become an ellipse, so that the rigid inner tooth ring and the flexible outer tooth cup are completely meshed at the long axis of the cam ring and completely separated at the short axis of the cam ring, and the continuous operation can generate high-torque output. As for in the operation process, through the deformable characteristic of the elastic element, the cam ring reduces the structural abrasion of related parts, and the effects of automatically aligning and improving the operation precision are achieved.

Preferably, each elastic element has a Shore hardness (Shore Durometer) between a60 and a90, such as a polymer material containing polyurethane, rubber, acrylic, silicone, or engineering plastic.

Preferably, each of the elastic elements may be formed by an elastic solid cylinder or a rigid solid cylinder covered by a layer of elastic material.

The detailed structure, characteristics, assembly, or use of the harmonic reducer according to the present invention will be described in the following detailed description of the embodiments. However, it should be understood by those skilled in the art that the detailed description and specific examples, while indicating the specific embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

Drawings

Fig. 1 is a perspective view of a harmonic reducer according to embodiment 1 of the present invention.

Fig. 2 is an exploded perspective view of a harmonic reducer according to embodiment 1 of the present invention.

Fig. 3 is a cross-sectional view of fig. 1 taken along line 3-3.

Fig. 4 is a plan view of the harmonic reducer according to embodiment 1 of the present invention, with some elements omitted.

Fig. 5 is a partially enlarged view of fig. 4.

Fig. 6 is similar to fig. 5, and mainly shows an elastic element provided in the harmonic reducer according to embodiment 2 of the present invention.

Description of the reference numerals

10: harmonic speed reducer

20: rigid internal gear ring

30: flexible external tooth cup

40: wave generator

41: bearing assembly

42: cam ring

421: inner ring surface

422: first concave part

43 shaft coupling

44: disc part

45: shaft part

451: peripheral surface

452: second concave part

46: gasket

47: gasket

48: retaining ring

50: elastic element

G: gap

D: diameter of the elastic element

60: elastic element

61: rigid solid cylinder

62: elastic material

Detailed Description

Applicants first describe herein, throughout this specification, including the examples and claims that follow, directional terms are used with respect to the drawings. Next, in the embodiments and drawings to be described below, the same reference numerals are used to designate the same or similar components or structural features thereof.

Referring to fig. 1 to 3, a harmonic reducer 10 according to embodiment 1 of the present invention includes a rigid inner ring gear 20, a flexible outer cup gear 30, a wave generator 40, and four elastic elements 50 (the number of the elastic elements 50 is not limited to four, and may be other numbers).

The flexible outer cup 30 is disposed within the rigid inner ring gear 20 and is partially engaged with the rigid inner ring gear 20.

The wave generator 40 has a bearing 41, a cam ring 42, and a coupling 43. The bearing 41 is arranged in the flexible outer tooth cup 30; the cam ring 42 is arranged in the bearing 41, and the inner ring surface 421 of the cam ring 42 is provided with four first concave parts 422; the shaft 43 has a disk 44 and a shaft 45 connecting the disk 44, wherein the disk 44 is disposed in the flexible outer cup 30 and is abutted by the bearing 41, the shaft 45 is sequentially inserted through the cam ring 42 and the two

washers

46, 47, and then assembled with the cam ring 42 by a retaining ring 48, so that the shaft 43 can drive the cam ring 42 to move together, and the outer circumferential surface 451 of the shaft 45 has four second recesses 452, and the four second recesses 452 of the shaft 45 correspond to the four first recesses 422 of the cam ring 42 in a one-to-one manner.

In the present embodiment, each elastic element 50 is an elastic solid cylinder made of a material (e.g., polyurethane-containing polymer material, rubber, acrylic, silicone, or engineering plastic) with a Shore hardness (Shore Durometer) between a60 and a90, so that each elastic element 50 has an anti-friction effect. As shown in fig. 2 and 4, the four elastic elements 50 are disposed in the four first recesses 422 of the cam ring 42 and the four second recesses 452 of the shaft portion 45 of the coupling 43 in a one-to-one manner, one end of each of the four elastic elements 50 is blocked by the disk portion 44 of the coupling 43, and the other end of each of the four elastic elements 50 is blocked by the spacer 47. Furthermore, as shown in FIG. 5, a gap between the inner annular surface 421 of the cam ring 42 and the outer peripheral surface 451 of the shaft portion 45 of the coupling 43 is defined as G, the tensile elastic modulus of the elastic element 50 is defined as K, K is greater than or equal to 0.1 and less than or equal to 0.5, and the diameter of the elastic element 50 is defined as D, which satisfy the following relation: g is more than or equal to 0 and less than or equal to KD, and through the relational expression, each elastic element 50 can reliably absorb the eccentricity generated during operation, and the phenomenon that each elastic element enters the gap G due to overlarge deformation is avoided, so that the transmission effect between the cam ring 42 and the coupler 43 is reduced.

As can be seen from the above, when the shaft 45 of the coupling 43 is driven by the power source, the cam ring 42 is driven to rotate together, and then the flexible outer tooth cup 30 is pushed by the cam ring 42 to become an ellipse, so that the rigid inner tooth ring 20 and the flexible outer tooth cup 30 are completely engaged at the long axis of the cam ring 42 and completely disengaged at the short axis of the cam ring 42, and thus the continuous operation can generate high torque output. In the operation process, due to the deformable characteristics of the four elastic elements 50, on one hand, the gap G is effectively eliminated to achieve the self-aligning function, and on the other hand, the abrasion generated between the cam ring 42 and the shaft part 45 of the coupler 43 can be corrected to achieve the purpose of improving the operation precision.

On the other hand, the structure of the elastic element may be variously changed. As shown in fig. 6, the elastic element 60 may also be made by wrapping a rigid solid cylinder 61 with a layer of elastic material 62, wherein the rigid solid cylinder 61 may be made of a material such as metal, and the material of the elastic material 62 is the same as that of the above embodiment, so that the elastic material 62 has the anti-friction property, and thus the elastic element 60 made by matching two different materials can achieve the effects of eliminating the gap, reducing the abrasion and improving the operation precision.

The above-mentioned embodiments, further detailed description of the objects, technical solutions and advantages of the present invention, it should be understood that the above-mentioned embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A harmonic reducer, comprising:

a rigid inner ring gear;

the flexible outer tooth cup is arranged in the rigid inner tooth ring and is partially meshed with the rigid inner tooth ring;

the wave generator is provided with a bearing, a cam ring and a coupler, the bearing is arranged in the flexible outer tooth cup, the cam ring is arranged in the bearing, the inner ring surface of the cam ring is provided with a plurality of first concave parts, the coupler is arranged in the cam ring in a penetrating mode, and the outer peripheral surface of the coupler is provided with a plurality of second concave parts; and

a plurality of elastic elements respectively arranged between the first concave part of the cam ring and the second concave part of the coupler, wherein a gap between the inner ring surface of the cam ring and the outer peripheral surface of the coupler is defined as G, the tensile elastic rate of the elastic elements is defined as K, the diameter of the elastic elements is defined as D, and the three satisfy the following relational expression: g is more than or equal to 0 and less than or equal to KD, wherein K is more than or equal to 0.1 and less than or equal to 0.5.

2. The harmonic reducer as in claim 1 wherein each of the elastic elements has a shore hardness between a60 and a 90.

3. The harmonic reducer as in claim 1 wherein each of the elastic elements is an elastic solid cylinder.

4. The harmonic reducer as in claim 1 wherein each of the elastic elements is made of a rigid solid cylinder wrapped with an elastic material.