Cycloidal speed reducer

Abstract

The utility model provides a cycloid speed reducer, which relates to the technical field and comprises an eccentric cam shaft, a first cycloid disc and a second cycloid disc. Roller pins are arranged between the peripheral wall of the eccentric cam shaft and the inner walls of the first cycloid disc and the second cycloid disc; mounting holes are formed in the first cycloid disc and the second cycloid disc in the thickness direction in a penetrating mode, and bolts are screwed into the penetrating mounting holes from one side of the gland and connected to the flange base. The structure further comprises a wave-shaped bush, the portion, corresponding to the mounting hole, of the bolt is sleeved with the wave-shaped bush in a penetrating mode, the outer surface of the wave-shaped bush is in a periodical fluctuating outline, and the outer surface of the wave-shaped bush and the inner wall of the mounting hole form multi-point discrete contact so as to relieve the stress concentration phenomenon between the wave-shaped bush and the inner wall of the mounting hole. The utility model has the beneficial effects that the multi-point discrete contact between the wave-shaped bushing and the inner wall of the mounting hole realizes the optimization and reconstruction of stress distribution, effectively inhibits the stress concentration phenomenon in the traditional continuous contact mode, and effectively prolongs the service life of the product.

Description

TECHNICAL FIELD

[0001] The utility model relates to transmission device technical field, especially a cycloidal speed reducer. BACKGROUND

[0002] Industrial robots provide joint movement for joint structures with multiple joint degrees of freedom through driving motors, servo motors, etc. In order to obtain high output torque from servo motors, etc., the joints of the robot are provided with reducers at the output end of the servo motor to increase the torsion. Industrial robots adopt harmonic drive or cycloidal drive to reduce the overall or part of the robot. Among them, the cycloidal drive is widely used in various industries. In the cycloidal drive, the power is transmitted from the input shaft to the output shaft through the meshing and rotation of the outer teeth of the cycloidal disc and the inner teeth of the pinwheel shell, so that large torque transmission can be achieved, and the speed reduction ratio can be greatly increased, that is, the cycloidal speed reducer currently used to reduce the stress of the bushing.

[0003] The cycloidal speed reducer is also called a cycloidal pinwheel reducer, which is a novel transmission device that applies the principle of planetary transmission and uses cycloidal pin teeth to mesh. Due to its excellent transmission performance and high reduction ratio, it is widely used in driving or speed reduction operations in various industries. The cycloidal reducer is usually constructed using two or more cycloidal discs and forming discs in opposite positions, and is constructed so that the load is not biased to one side.

[0004] The weak point (position of maximum stress) of the cycloidal speed reducer is mainly located in the contact area between the cycloidal gear disc mounting hole and the bushing. In theory, it is a linear contact, but in practice, the bushing used at present is a regular cylindrical shape, as shown in Figure 1 The contact position between the bushing and the mounting hole is basically in the A area, that is, edge contact stress concentration occurs. In addition, other bushings in the circumferential direction also have uneven contact, which can cause more obvious stress concentration and easily induce fatigue cracks. Therefore, it is necessary to disclose a cycloidal speed reducer to overcome the above-mentioned defects. INVENTION CONTENTS

[0005] The utility model overcomes the defects in the prior art and provides a cycloidal speed reducer, which is provided with a wave-shaped bushing at the mounting hole of the bolt and the first and second cycloidal discs, so that multiple discrete contacts are formed to reduce the stress concentration phenomenon between the wave-shaped bushing and the inner wall of the mounting hole and prolong the service life.

[0006] To solve the above technical problems, the utility model is implemented by the following technical solutions:

[0007] A cycloidal speed reducer comprises:

[0008] The eccentric camshaft is provided with a first cycloid disc and a second cycloid disc with a phase difference of 180 degrees at two ends of the eccentric camshaft; and a needle roller is arranged between the outer peripheral wall of the eccentric camshaft and the inner wall of the first cycloid disc and the second cycloid disc.

[0009] The flange seat, the gland and the needle wheel hub are provided with a thin cross roller bearing therebetween, so that the needle wheel hub can rotate relative to the flange seat and the gland.

[0010] The outer periphery of the first cycloid disc and the second cycloid disc is provided with cycloid teeth, which form a gear difference internal meshing speed reduction mechanism with needle teeth annularly distributed on the inner wall of the needle wheel hub.

[0011] The first cycloid disc and the second cycloid disc are provided with mounting holes penetrating in the thickness direction, and a bolt is screwed into the mounting holes from one side of the gland and connected to the flange seat.

[0012] The bolt is provided with a wave-shaped bushing at the corresponding mounting hole, and the outer surface of the wave-shaped bushing has a periodic undulating profile, which forms a multi-point discrete contact with the inner wall of the mounting hole, so as to alleviate the stress concentration phenomenon between the wave-shaped bushing and the inner wall of the mounting hole.

[0013] Further, the outer peripheral wall of the eccentric camshaft is provided with a deep groove bearing between the flange seat and the gland.

[0014] Further, the eccentric camshaft is provided with a first oil seal between the gland and the flange seat.

[0015] Further, the needle wheel hub is provided with a second oil seal between the gland and the flange seat.

[0016] Compared with the prior art, the utility model has the beneficial effects that:

[0017] The utility model provides a cycloid speed reduction device, which is provided with a wave-shaped bushing at the mounting hole of the bolt, the first cycloid disc and the second cycloid disc, so as to form a multi-point discrete contact, alleviate the stress concentration phenomenon between the wave-shaped bushing and the inner wall of the mounting hole, realize the optimization and reconstruction of stress distribution, effectively inhibit the stress concentration phenomenon under the traditional continuous contact mode, and effectively prolong the service life of the product. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the utility model, together with the embodiments of the utility model, to explain the utility model, and do not constitute a limitation to the utility model, in the drawings:

[0019] Figure 1 It is a schematic view of the contact position of the traditional cylindrical bushing and the mounting hole of the cycloid disc;

[0020] Figure 2is a perspective view of the cycloid reduction device of the utility model;

[0021] Figure 3 is a sectional view of the cycloid reduction device of the utility model;

[0022] Figure 4 is an explosion view of the cycloid reduction device of the utility model;

[0023] Figure 5 is a structural schematic view of the wave-shaped bushing;

[0024] Figure 6 is a schematic view of the installation hole contact position of the wave-shaped bushing and the cycloid disc.

[0025] In the drawing:

[0026] 1, eccentric camshaft;2, first cycloid disc;201, installation hole;3, second cycloid disc;4, needle roller;5, flange seat;6, gland;7, needle wheel hub;8, wave-shaped bushing;9, bolt;10, thin cross roller bearing;11, deep groove bearing;12, first oil seal;13, second oil seal;

[0027] A, traditional cylindrical bushing and cycloid disc contact area;B, wave-shaped bushing and cycloid disc contact area. DETAILED DESCRIPTION

[0028] The preferred embodiments of the utility model are described below in conjunction with the drawings, and it should be understood that the preferred embodiments described here are only for illustrating and explaining the utility model, and are not for limiting the utility model.

[0029] As Figure 2 indicated in the figure, Figure 6 the utility model requests protecting a kind of cycloid reduction device, comprising: eccentric camshaft 1, and the first cycloid disc 2 and the second cycloid disc 3 of phase difference 180 ° are arranged at its both ends different shaft, and the outer peripheral wall of eccentric camshaft 1 is provided with needle roller 4 between the inner wall of first cycloid disc 2 and second cycloid disc 3, and needle roller 4 and cycloid gear wheel form the force transmission path of multiple-point contact, and the high-speed rotary motion of eccentric camshaft 1 is transmitted to the rotation of first cycloid disc 2 and second cycloid disc 3 by the rolling contact of needle roller 4.

[0030] The outer periphery of first cycloid disc 2 and second cycloid disc 3 is provided with cycloid gear teeth, and needle gear teeth are annularly distributed in the inner wall of needle wheel hub 7, forming a gear difference internal meshing reduction mechanism;Cycloid disc generates compound motion under the action of eccentric camshaft 1: both revolve around eccentric camshaft 1 axis (eccentric motion), and also reverse rotation around its axis due to tooth profile constraint;The continuous multiple-point contact of needle gear teeth and cycloid gear teeth makes load distribution more uniform, which helps to improve transmission efficiency.The above is also the prior art of cycloid reduction device, which is not described here.

[0031] The eccentric camshaft 1 is rotatably arranged outside the flange seat 5 and the gland 6, and specifically, the eccentric camshaft 1 is rotatably connected with the flange seat 5 and the gland 6 through a thin cross roller bearing 10.

[0032] The deep groove bearing 11 is arranged between the outer peripheral wall of the eccentric camshaft 1 and the flange seat 5 and the gland 6.

[0033] In order to enhance the sealing performance of the structure, the first oil seal 12 is arranged between the eccentric camshaft 1 and the gland 6 and the flange seat 5, and the second oil seal 13 is arranged between the needle wheel hub 7 and the gland 6 and the flange seat 5. Through the arrangement of the first oil seal 12 and the second oil seal 13, the leakage of lubricating oil to the inside can be prevented, and the components requiring lubrication in the transmission part and the output part are isolated.

[0034] The mounting hole 201 is arranged on the first cycloid disc 2 and the second cycloid disc 3 along the thickness direction, the bolt 9 is screwed into the mounting hole 201 from one side of the gland 6 and connected to the flange seat 5, so that the first cycloid disc 2 and the second cycloid disc 3 are connected with the gland 6 and the flange seat 5 integrally.

[0035] The main design point of the cycloid speed reducer is that the wave-shaped bushing 8 is sleeved on the mounting hole 201 of the bolt 9, and the bolt 9 is connected to the flange seat 5. Figure 5 As can be seen, the outer surface of the wave-shaped bushing 8 is periodically undulating, so that it can form multi-point discrete contact with the inner wall of the mounting hole 201. Figure 6 As shown, the contact position of the wave-shaped bushing 8 and the mounting hole 201 of the cycloid disc is the B area, which is located in the middle position of the mounting hole 201 and is in multi-point contact, so as to slow down the stress concentration phenomenon between the wave-shaped bushing 8 and the inner wall of the mounting hole 201, realize the optimization reconstruction of stress distribution, effectively inhibit the stress concentration phenomenon in the traditional continuous contact mode, and effectively prolong the service life of the product.

[0036] Finally, it should be pointed out 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 principles of the present application should be included in the protection scope of the present application.

Claims

1. A cycloidal deceleration device, characterized in that, include: An eccentric camshaft (1) has a first cycloidal disk (2) and a second cycloidal disk (3) with a phase difference of 180° at its two ends, and a needle roller (4) is provided between the outer peripheral wall of the eccentric camshaft (1) and the inner walls of the first cycloidal disk (2) and the second cycloidal disk (3). It also includes a flange seat (5), a gland (6) and a needle hub (7), with a thin cross roller bearing (10) provided between the flange seat (5) and the gland (6) and the needle hub (7) so that the needle hub (7) can rotate relative to the flange seat (5) and the gland (6); The outer periphery of the first cycloidal disk (2) and the second cycloidal disk (3) is provided with cycloidal teeth, which form a tooth difference internal meshing deceleration mechanism with the needle teeth distributed in a ring on the inner wall of the needle wheel hub (7); The first cycloidal disc (2) and the second cycloidal disc (3) have through holes (201) along the thickness direction. Bolts (9) are screwed into the through holes (201) from one side of the cover (6) and connected to the flange seat (5). It also includes a wavy bushing (8), on which the wavy bushing (8) is fitted on the bolt (9) at the corresponding mounting hole (201). The outer surface of the wavy bushing (8) has a periodic undulating profile, forming multi-point discrete contact with the inner wall of the mounting hole (201) to reduce the stress concentration phenomenon between the wavy bushing (8) and the inner wall of the mounting hole (201).

2. The cycloidal deceleration device according to claim 1, characterized in that, Deep groove bearings (11) are provided between the outer peripheral wall of the eccentric camshaft (1), the flange seat (5), and the cover (6).

3. The cycloidal deceleration device according to claim 1, characterized in that, A first oil seal (12) is provided between the eccentric camshaft (1), the gland (6), and the flange seat (5).

4. The cycloidal deceleration device according to claim 3, characterized in that, A second oil seal (13) is provided between the pin hub (7), the gland (6), and the flange seat (5).

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