Novel torsion limiting harmonic speed reducer

Abstract

The utility model provides a novel torsion limiting harmonic speed reducer, which relates to the technical field of speed reducers, and comprises a wave generator and a torsion limiter, the wave generator is connected with a flexible gear, and the flexible gear is meshed with a rigid gear; the torsion limiter is composed of an inner hole shaft and a flexible gear connecting ring, and the inner hole shaft and the flexible gear connecting ring are dynamically coupled through balls and meshing ball positions. The flexible gear is connected with the flexible gear connecting ring; the inner hole shaft is connected with the connecting shaft; and the inner hole shaft is movably connected with the flexible gear connecting ring. The harmonic speed reducer has the advantages that the torsion limiter is arranged, when the harmonic speed reducer is impacted to cause abnormal torque overload, the torsion limiter forces the flexible gear to be disconnected with the connecting shaft, so that mechanical damages such as permanent deformation of the tooth shape of the flexible gear and clamping stagnation of a flexible gear bearing of a wave generator caused by mechanical impact are avoided, and the service life of the harmonic speed reducer is prolonged. And a winding of a driving motor connected with the flexible gear is prevented from being overloaded and burnt, so that overload protection on mechanical equipment is achieved, and the safety of the collaborative robot and the humanoid robot can be improved through the separation capacity.

Description

TECHNICAL FIELD

[0001] The utility model relates to a speed reducer technical field especially a novel torsion limit harmonic speed reducer. BACKGROUND

[0002] The harmonic reducer is a high-precision transmission device based on the principle of elastic deformation, and its core structure is composed of three key components: a rigid gear, a flexible gear, and a wave generator. The rigid gear is a rigid internal gear, and the flexible gear is an elastic external gear made of high-strength thin-wall alloy material. The two gears are meshed through a difference in the number of teeth (usually 2 teeth). The wave generator, as a power input component, forces the flexible gear to periodically deform by cooperating with an elliptical cam and a flexible bearing, achieving dynamic adjustment of the tooth contact area.

[0003] During operation, the rotation of the wave generator drives the flexible gear to deform radially, causing the teeth of the flexible gear to mesh with the teeth of the rigid gear in the long axis area of the ellipse and disengage in the short axis area. This periodic deformation causes relative movement between the flexible gear and the rigid gear, achieving a reduction effect through the difference in the number of teeth. The single-stage transmission ratio can reach 70-320, and multi-stage combination can achieve an ultra-high speed ratio of over 30,000.

[0004] The core advantages of this device are: ① high transmission precision (error is only 1 / 4 of ordinary gears), thanks to the error homogenization effect of multiple teeth meshing simultaneously; ② high torque density per unit volume, with a load capacity 2-3 times that of traditional structures; ③ zero backlash feature, achieving zero backlash meshing through pre-deformation, particularly suitable for precision positioning scenarios; ④ compact structure, with a volume reduction of over 30% and a weight reduction of about 50% compared to reducers of the same specifications.

[0005] In industrial applications, the harmonic reducer has become a core component of industrial robot joint drives, widely used in precision motion control fields such as six-axis robot arms and collaborative robots. At the same time, its high reliability and lightweight characteristics also make it play an important role in aerospace servo mechanisms, medical surgical robots, and high-end numerical control equipment. The latest technology development focuses on fatigue life improvement, with surface strengthening treatment and topology optimization design, the service life has been improved to over 10,000 hours.

[0006] During the operation of industrial equipment, the harmonic reducer, as a precision transmission mechanism, often faces sudden impact loads. Due to the high-strength thin-wall alloy structure of the flexible gear component of the reducer, when the equipment motion joint is subjected to abnormal collision, the instantaneous peak torque generated will directly act on the core components of the reducer through the rigid gear ring. This mechanical impact not only causes permanent deformation of the flexible gear teeth, mechanical damage such as wave generator bearing jamming, but also causes overloading and burning of the drive motor winding through the power transmission path.

[0007] The technical content disclosed by the Chinese patent document (publication number: CN220622645U, patent name: harmonic reducer) is: the harmonic reducer comprises a flexspline, a wave generator and a rigid wheel. The surface hardness of the first nitriding layer provided on the surface of the flexspline is 550HV to 750HV, so that the flexspline has better wear resistance, the first tooth part and the first inner hole have better wear resistance, the wear amount when the second tooth part of the rigid wheel is engaged is reduced, and the service life of the flexspline is improved. The surface hardness of the first nitriding layer of the rigid wheel is 450HV to 650HV, so that the rigid wheel has certain strength and wear resistance. The hardness of the first nitriding layer is greater than the hardness of the second nitriding layer, which can effectively improve the wear condition of the flexspline, improve the service life of the flexspline, and reduce the replacement frequency; the cost of replacing the rigid wheel is lower than the cost of replacing the flexspline, so the use cost of the harmonic reducer can be reduced.

[0008] As can be known from the above embodiment and the corresponding drawings, the harmonic reducer only increases the wear resistance of the flexspline and the rigid wheel to improve the service life of the reducer, and does not involve the overload protection mechanism of the power transmission chain. When the equipment encounters abnormal collision, the instantaneous impact torque will still act on the thin-walled structure of the flexspline through the rigid transmission path. Utility model content

[0009] The utility model overcomes the shortcoming in the prior art, provides a novel torque limiting harmonic reducer, sets up the torque limiter, when the harmonic reducer bears abnormal torque, the torque limiter forces the connection of the flexspline and the connecting shaft to be disconnected, avoids the mechanical impact to cause the permanent deformation of the flexspline tooth shape, the mechanical damage such as the flexspline bearing of the wave generator is stuck, also avoids the overloading burnout of the driving motor winding connected with the flexspline, thereby plays the overload protection to the mechanical equipment, and this separation capacity can increase the safety of the collaborative robot and the humanoid robot.

[0010] In order to solve the above technical problem, the utility model is realized through the following technical scheme:

[0011] A novel torque limiting harmonic reducer, including wave generator and torque limiter, wave generator is connected flexspline, and flexspline is engaged with rigid wheel;

[0012] The torque limiter is composed of an inner hole shaft and a flexspline connecting ring, and the two are dynamically coupled through balls and engagement balls;

[0013] The flexspline is connected with the flexspline connecting ring, and the inner hole shaft is connected with the connecting shaft;The inner hole shaft is movably connected with the flexspline connecting ring;

[0014] The connecting shaft is connected with a cross roller bearing, and the cross roller bearing comprises a bearing inner ring, a bearing outer ring and cross rollers;

[0015] The bearing outer ring is composed of a bearing first outer ring and a bearing second outer ring through an axial joint surface, and the bearing inner ring covers the inner side radial contact surface of the crossed roller.

[0016] Further, the outer circumferential radial extension of the inner hole shaft is provided with a first meshing ball position, the bottom surface of the flexspline connecting ring is provided with a second meshing ball position, the first meshing ball position and the second meshing ball position form an included angle, and the ball is clamped in the included angle formed by the first meshing ball position and the second meshing ball position.

[0017] Further, the side of the ball away from the first meshing ball position and the second meshing ball position is provided with a disengagement ring, the inner circumferential surface of the disengagement ring generates a radial constraint force through elastic deformation, so that the ball maintains bidirectional contact with the first meshing ball position and the second meshing ball position; the line connecting the annular contact surface of the disengagement ring and the ball center is in complementary geometric relationship with the pressure angle formed by the first meshing ball position and the second meshing ball position.

[0018] Further, the wave generator comprises a camshaft and a flexspline bearing.

[0019] Further, the crossed roller bearing is connected to an adapter disc, and the adapter disc is connected to the rigid wheel.

[0020] Compared with the prior art, the harmonic reducer has the beneficial effects that:

[0021] The torsion limiter is arranged, when the torsion of the harmonic reducer is overloaded, the torsion limiter forces the flexspline to be disconnected with the connecting shaft, so that the flexspline cannot be reversely braked by the connecting shaft, mechanical impact caused permanent deformation of the flexspline tooth shape, mechanical damage such as flexspline bearing jamming of the wave generator is avoided, and the winding of the driving motor connected with the flexspline is also prevented from being burned out, the instantaneous disconnection of the connecting component can also avoid impact load accumulation, so that the mechanical equipment is protected from overload, and when the equipment is impacted, the disconnection capability can increase the safety of the collaborative robot and the humanoid robot. BRIEF DESCRIPTION OF DRAWINGS

[0022] The accompanying drawings are used to provide a further understanding of the harmonic reducer, and are used together with the embodiments of the harmonic reducer to explain the harmonic reducer, and do not constitute a limitation on the harmonic reducer, and in the drawings:

[0023] Figure 1 is a general schematic view of the harmonic reducer of the embodiment of the harmonic reducer;

[0024] Figure 2 is a first cross-sectional view of the harmonic reducer of the embodiment of the harmonic reducer;

[0025] Figure 3 is a second cross-sectional view of the harmonic reducer of the embodiment of the harmonic reducer;

[0026] Figure 4 is an explosion schematic view of a harmonic reducer according to an embodiment of the present application;

[0027] Figure 5 is a cross-sectional view of a cross roller bearing according to an embodiment of the present application;

[0028] Figure 6 is an explosion schematic view of a wave generator and a flexspline according to an embodiment of the present application;

[0029] Figure 7 is an explosion schematic view of a torque limiter according to an embodiment of the present application;

[0030] Figure 8 is a cross-sectional view of a torque limiter according to an embodiment of the present application.

[0031] In the figure: 1, wave generator; 101, camshaft; 102, flexspline bearing; 2, rigid gear; 3, torque limiter; 301, inner hole shaft; 3011, first meshing ball site; 302, flexspline connecting ring; 3021, second meshing ball site; 303, ball; 304, disengaging ring; 4, flexspline; 5, adapter disc; 6, connecting shaft; 7, cross roller bearing; 701, bearing inner ring; 702, bearing first outer ring; 703, bearing second outer ring; 704, cross roller; 705, sealing ring. DETAILED DESCRIPTION

[0032] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, which should be understood as merely illustrative and explanatory, and not limiting the present application.

[0033] As shown in Figures 1 to 8 , a harmonic reducer with torque limitation includes a wave generator 1 and a torque limiter 3, the wave generator 1 is connected to a flexspline 4, the flexspline 4 is engaged with a rigid gear 2; the torque limiter 3 is composed of an inner hole shaft 301 and a flexspline connecting ring 302, and the two are dynamically coupled through balls 303 and meshing ball sites; the flexspline 4 is connected to the flexspline connecting ring 302, the inner hole shaft 301 is connected to a connecting shaft 6; the inner hole shaft 301 is movably connected to the flexspline connecting ring 302.

[0034] When the impact torque exceeds the preset upper limit, the balls 303 are disengaged from the inner hole shaft 301, achieving mechanical decoupling of the flexspline 4 and the connecting shaft 6, so that the flexspline 4 will not be reversely braked by the connecting shaft 6, avoiding mechanical damage such as permanent deformation of the flexspline 4 tooth profile, jamming of the flexspline bearing 102 of the wave generator 1, and also avoiding overloading and burning of the winding of the driving motor connected to the flexspline 4, and the instantaneous disengagement of the connecting components can also avoid the accumulation of impact load, thereby providing overload protection for the mechanical equipment.

[0035] The outer periphery of the inner hole shaft 301 is provided with a first meshing ball position 3011, the bottom surface of the flexible gear connecting ring 302 is provided with a second meshing ball position 3021, the first meshing ball position 3011 and the second meshing ball position 3021 form an included angle, the ball 303 is clamped in the included angle formed by the first meshing ball position 3011 and the second meshing ball position 3021, the side of the ball 303 away from the first meshing ball position 3011 and the second meshing ball position 3021 is provided with a disengaging ring 304, the inner periphery surface of the disengaging ring 304 generates a radial constraint force through elastic deformation, so that the ball 303 is kept in bidirectional contact with the first meshing ball position 3011 and the second meshing ball position 3021; the line connecting the annular contact surface of the disengaging ring 304 and the ball center of the ball 303 and the pressure angle formed by the first meshing ball position 3011 and the second meshing ball position 3021 are in complementary geometric relationship, when mechanical impact occurs, the disengaging ring 304 is disengaged away from the included angle, so that the ball 303 is no longer clamped in the included angle, after the ball 303 is disengaged, there is no intermediate medium connecting between the first meshing ball position 3011 and the second meshing ball position 3021, so that the motion of the inner hole shaft 301 and the flexible gear connecting ring 302 does not interfere with each other, so that the linkage of the two can be disengaged.

[0036] The wave generator 1 includes a camshaft 101 and a flexible gear bearing 102, the wave generator 1 serves as a power input component, through the cooperation of the elliptical cam and the flexible bearing 102, the flexible gear 4 is forced to periodically elastically deform, the dynamic adjustment of the tooth surface contact area is realized, in the working process, the rotation of the wave generator 1 drives the flexible gear 4 to generate radial deformation, so that the flexible gear teeth and the rigid gear teeth are in meshing in the elliptical long axis area, and are in disengagement in the short axis area, so that the speed change of the two end connecting components of the speed reducer is realized.

[0037] The connecting shaft 6 is connected with the cross roller bearing 7, the cross roller bearing 7 is connected with the adapter disc 5, the adapter disc 5 is connected with the rigid gear 2, the cross roller bearing 7 includes a bearing inner ring 701, a bearing outer ring and cross rollers 704, the bearing inner ring 701 and the bearing outer ring are provided with lubricating grease therebetween, a sealing ring 705 is arranged between the bearing second outer ring 703 and the bearing inner ring 701, in the embodiment, the sealing ring 705 is a fluorine rubber sealing ring, the cross section of the sealing ring 705 is in a lip-shaped structure to realize bidirectional dust prevention and grease blocking.

[0038] Finally, it should be noted that: the above is only the preferred embodiment of the present application, and is not used to limit the present application, although the present application has been described in detail with reference to the embodiments, for those skilled in the art, the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced, but any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A novel torque-limiting harmonic reducer, characterized by, It comprises a wave generator (1) and a torque limiter (3), the wave generator (1) is connected with a flexible gear (4), the flexible gear (4) is engaged with a rigid gear (2); The torque limiter (3) is composed of an inner hole shaft (301) and a flexible gear connecting ring (302), and the two are dynamically coupled through a ball (303) and an engaging ball position; The flexible gear (4) is connected with the flexible gear connecting ring (302), and the inner hole shaft (301) is connected with a connecting shaft (6); the inner hole shaft (301) is movably connected with the flexible gear connecting ring (302); The connecting shaft (6) is connected with a cross roller bearing (7), and the cross roller bearing (7) comprises a bearing inner ring (701), a bearing outer ring and cross rollers (704); The bearing outer ring is composed of a bearing first outer ring (702) and a bearing second outer ring (703) through an axial joint surface, and the two cooperatively cover the outer side radial contact surface of the cross roller (704), and the bearing inner ring (701) covers the inner side radial contact surface of the cross roller (704).

2. The novel torque-limiting harmonic gear reducer according to claim 1, wherein The outer periphery of the inner hole shaft (301) is provided with a first engaging ball position (3011) extending radially, the bottom surface of the flexible gear connecting ring (302) is provided with a second engaging ball position (3021), the first engaging ball position (3011) and the second engaging ball position (3021) form an included angle, and the ball (303) is clamped in the included angle formed by the first engaging ball position (3011) and the second engaging ball position (3021).

3. The novel torque-limiting harmonic gear reducer according to claim 2, wherein The side of the ball (303) away from the first engaging ball position (3011) and the second engaging ball position (3021) is provided with a ring (304), the inner periphery of the ring (304) generates a radial constraint force through elastic deformation, so that the ball (303) maintains bidirectional contact with the first engaging ball position (3011) and the second engaging ball position (3021); the line connecting the ring contact surface of the ring (304) and the ball center of the ball (303) and the pressure angle formed by the first engaging ball position (3011) and the second engaging ball position (3021) are in complementary geometric relationship.

4. The novel torque-limiting harmonic gear reducer according to claim 3, wherein The wave generator (1) comprises a camshaft (101) and a flexible gear bearing (102).

5. The novel torque-limiting harmonic gear reducer according to any one of claims 1 to 4, characterized in that, The cross roller bearing (7) is connected with a transfer disc (5), and the transfer disc (5) is connected with the rigid gear (2).

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