An eccentric swing type gear device

Abstract

The center of the swing gear of an eccentric swing type gear device in the present invention has a process hole, and the multiple crankshaft holes of the swing gear are symmetrically distributed relative to the center of the process hole. The process hole and the inner surface of the crankshaft hole are finely processed to form a first positioning surface and a second positioning surface, which are used to cooperate with the fixture, and when the first swing gear and the second swing gear are adjusted to have the same external tooth shape, that is, the crankshaft hole of the first swing gear is opposite to the eccentric hole of the second swing gear, and then they are processed in pairs. That is, the coaxiality of the first swing gear and the second swing gear is guaranteed during processing; at the same time, the accuracy of the external teeth of the first swing gear and the second swing gear and the consistency of the tooth shape are guaranteed.

Description

Technical Field

[0001] The invention relates to the field of eccentric swing gear devices, and in particular to a swing gear structure of an RV reducer. Background Art

[0002] RV reducer is an eccentric swing type gear device, which consists of a planetary gear reducer front stage and a cycloid pinwheel reducer rear stage. RV reducer has a compact structure, a large transmission ratio, and a transmission mechanism with self-locking function under certain conditions. It is one of the most commonly used reducers with low vibration, low noise and low energy consumption.

[0003] The swing gear structure is the core component of the RV reducer. To achieve high transmission efficiency, very high requirements are placed on the processing accuracy and matching accuracy of the swing gear and the planetary carrier. In the structure of the RV reducer, the swing gears are used in pairs, and the phase difference between the two swing gears is 180 degrees. How to ensure the accuracy of the external teeth of the two swing gears is a problem that technicians in this field need to solve.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The object of the present invention is to provide a RV reducer swing gear structure.

[0006] The present invention is achieved in the following manner.

[0007] An eccentric swinging gear device comprises an outer cylinder, a swinging gear, a crankshaft and a gear frame, the crankshaft being formed with an eccentric portion; a crankshaft bearing supporting the crankshaft and enabling the crankshaft to rotate; a swinging gear having a crankshaft hole for inserting the eccentric portion and having a tooth portion; an outer cylinder having internal teeth meshing with the tooth portion of the swinging gear; a gear frame for mounting the crankshaft bearing, wherein the swinging gear swings along with the rotation of the eccentric portion to generate a relative rotation speed difference between the swinging gear and the outer cylinder, and a mounting portion is formed on the gear frame for mounting the crankshaft bearing, characterized in that: a process hole is provided at the center of the swinging gear, and a plurality of crankshaft holes of the swinging gear are symmetrically distributed relative to the center of the process hole, and the process hole and the inner surface of the crankshaft hole are finely machined to form a first positioning surface and a second positioning surface for cooperating with a fixture.

[0008] The swing gear includes a first swing gear and a second swing gear, and the first swing gear and the second swing gear are 180 degrees out of phase with each other.

[0009] The clamp has a base, on which are provided two side positioning columns and a center positioning column. The two side positioning columns are respectively a first side positioning column and a second side positioning column. The first side positioning column and the second side positioning column are respectively located on both sides of the center positioning column, and the first side positioning column, the center positioning column and the second side positioning column are in a straight line.

[0010] The first swing gear is sleeved on the fixture, and the first swing gear is respectively positioned and matched with the first side positioning column and the center positioning column; the second swing gear is sleeved on the fixture, and the second swing gear is positioned and matched with the second side positioning column and the center positioning column.

[0011] The present invention adopts a method of processing two swing gears in pairs, and during the processing, the first swing gear and the second swing gear are adjusted to have the same external tooth profile, that is, the crankshaft hole of the first swing gear is directly opposite to the eccentric hole of the second swing gear, and then they are processed in pairs. That is, the coaxiality of the first swing gear and the second swing gear is guaranteed during processing; at the same time, the accuracy of the external teeth of the first swing gear and the second swing gear and the consistency of the tooth profile are guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A cross-sectional view of the swing gear structure of the RV reducer of the present invention;

[0013] Figure 2 It is a cross-sectional view of the outer cylinder of the swing gear structure of the RV reducer of the present invention;

[0014] Figure 3 A schematic diagram of a crankshaft of an RV speed reducer swing gear structure of the present invention;

[0015] Figure 4 It is a front view of the first swing gear of the swing gear structure of the RV reducer of the present invention;

[0016] Figure 5 It is a front view of the second swing gear of the swing gear structure of the RV reducer of the present invention.

[0017] Figure 6 This is a view showing that the outer teeth of the first and second swing gears of the swing gear structure of the RV reducer of the present invention are placed in the same shape.

[0018] Figure 7 Schematic diagram of the fixture for the swing gear structure of the RV reducer of the present invention

[0019] Figure 8 Schematic diagram of placing the first and second swing gears of the swing gear structure of the RV reducer of the present invention on a fixture

[0020] In order to better understand the present invention, the component numbers of the RV reducer swing gear structure in the present invention are given below, where:

[0021] Needle gear housing 1; needle tooth groove 11; inner tooth 2; needle tooth 21; first swing gear 31; second swing gear 32; first swing gear outer tooth 311; first swing gear through hole 312; first swing gear crankshaft hole 313; first process hole 314; second swing gear outer tooth 321; second swing gear through hole 322; second swing gear crankshaft hole 323; second process hole 324; gear frame 4; output planetary frame 41; columnar body 411; input planetary frame 42; bearing 51; first tapered roller bearing 52; second tapered roller bearing 53; needle roller bearing 54; crankshaft 6; eccentric part 61; input gear 7; fixture 13, side positioning column 131, center positioning column 132. DETAILED DESCRIPTION Example

[0022] An eccentric swing type gear device includes an outer cylinder, a swing gear, a crankshaft and a gear frame. The crankshaft is formed with an eccentric portion; a crankshaft bearing supports the crankshaft and enables the crankshaft to rotate; the swing gear is a swing gear having a crankshaft hole for inserting the eccentric portion and a tooth portion; the outer cylinder has internal teeth meshing with the tooth portion of the swing gear; the gear frame is used to mount the crankshaft bearing, and the swing gear swings with the rotation of the eccentric portion to generate a relative speed difference between the swing gear and the outer cylinder, and the gear frame is formed with: a mounting portion for mounting the crankshaft bearing.

[0023] The outer cylinder is composed of a needle tooth housing 1 and inner teeth 2.

[0024] Two annular swing gears are accommodated side by side in the axial direction of the outer cylinder, namely, a first swing gear 31 and a second swing gear 32. The first swing gear 31 is arranged inside the outer cylinder and is mounted on the first eccentric part of the crankshaft through a roller bearing. When the first eccentric part of the crankshaft rotates eccentrically, the first swing gear 31 rotates while meshing with the internal teeth in conjunction with the eccentric rotation of the first eccentric part.

[0025] The outer diameter of the first swing gear 31 is slightly smaller than the inner diameter of the outer cylinder. The first swing gear 31 includes a first swing gear outer tooth 311, a first swing gear through hole 312, a first swing gear crankshaft hole 313 and a first process hole 314. The first swing gear outer tooth 311 has a wave shape that is smoothly continuous in the circumferential direction of the first swing gear 31.

[0026] The first process hole 314 is provided at the radial center portion of the first swing gear 31 .

[0027] The first swing gear through holes 312 are arranged on the first swing gear outer teeth 311 at equal intervals along the circumferential direction around the central crankshaft hole. The first swing gear through holes 312 are used to pass the columnar body 411 of the planet carrier.

[0028] A plurality of first swing gear crankshaft holes 313 are arranged around the central crankshaft hole at equal intervals along the circumferential direction on the first swing gear 31. Each first swing gear crankshaft hole 313 is arranged between adjacent first swing gear through holes 312 in the circumferential direction. The corresponding shaft portion passes through each first swing gear crankshaft hole 313.

[0029] The second swing gear 32 is disposed in the closed space inside the outer cylinder, arranged in parallel with the first swing gear, and is mounted on the second eccentric portion of each crankshaft through a second roller bearing. The first swing gear 31 and the second swing gear 32 are arranged in the axial direction corresponding to the positions of the first eccentric portion and the second eccentric portion. When each crankshaft rotates and the second eccentric portion rotates eccentrically, the second swing gear 32 rotates while meshing with the internal teeth in conjunction with the eccentric rotation of the second eccentric portion.

[0030] The outer diameter of the second swing gear 32 is smaller than the inner diameter of the outer cylinder, and the second swing gear 32 also has second swing gear outer teeth 321, a second swing gear through hole 322, a second swing gear crankshaft hole 323, and a second process hole 324. The second eccentric portion of the crankshaft passes through each second through hole in a state where a second roller bearing is interposed therein.

[0031] The first swing gear 31 and the second swing gear 32 are 180 degrees out of phase. After one of the swing gears is rotated 180 degrees, the outer tooth shape of the swing gear is the same as the outer tooth shape of the other swing gear. Based on this feature, in order to ensure the outer tooth accuracy and outer tooth shape of the two swing gears are consistent, we propose a method of processing the two swing gears in pairs. During the processing, the first swing gear 31 is placed on the fixture first, and then the second swing gear 32 is placed. After the second swing gear 32 is adjusted 180 degrees, its outer tooth shape is the same as the first swing gear 31 and then placed on the fixture. At this time, the tooth shape of the first swing gear outer tooth 311 of the first swing gear 31 and the second swing gear outer tooth 321 is consistent, that is, the first swing gear crankshaft hole 313 of the first swing gear 31 is opposite to the second swing gear through hole 322 of the second swing gear 32, and then they are processed in pairs.

[0032] The clamp 13 has a base, on which are provided two side positioning columns 131 and a center positioning column 132. The two side positioning columns 131 are respectively a first side positioning column and a second side positioning column. The first side positioning column and the second side positioning column are respectively located on both sides of the center positioning column 132, and the first side positioning column, the center positioning column and the second side positioning column are in a straight line.

[0033] In the present invention, when processing the outer teeth of the swing gear, firstly, the process hole in the middle of the swing gear is finely processed to ensure that the process hole has a smooth, high-precision inner surface as the first positioning surface for clamping, and then the crankshaft hole of the swing gear is finely processed to form a second positioning surface. The first swing gear 31 is sleeved on the fixture, and the first swing gear 31 is positioned and matched with the first side positioning column and the center positioning column respectively, and then the second swing gear 32 is sleeved on the fixture. At this time, the second swing gear 32 is positioned and matched with the second side positioning column and the center positioning column, and then the swing gears are processed in pairs, and at this time, the center of the first process hole and the center of the second process hole are placed on the same axis, and at the same time, the first swing gear crankshaft hole 313 is opposite to the second swing gear through hole 322 of the second swing gear 32. The coaxiality of the first swing gear 31 and the second swing gear 32 is ensured during processing; and the precision and consistency of the outer teeth of the first swing gear outer teeth 311 and the second swing gear outer teeth 321 are also ensured.

[0034] It should be pointed out that, for those skilled in the art, several improvements and modifications may be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. An eccentric swing type gear device, comprising an outer cylinder, a swing gear, a crankshaft and a gear frame, wherein the crankshaft is formed with an eccentric portion; a crankshaft bearing, which supports the crankshaft and enables the crankshaft to rotate; the swing gear, which has a crankshaft hole for inserting the eccentric portion and has a tooth portion; the outer cylinder has internal teeth that mesh with the tooth portion of the swing gear; the gear frame is used to mount the crankshaft bearing, and the swing gear swings with the rotation of the eccentric portion to generate a relative speed difference between the swing gear and the outer cylinder, and a mounting portion is formed on the gear frame, which is used to mount the crankshaft bearing, characterized in that: The center of the swing gear has a process hole, and the multiple crankshaft holes of the swing gear are symmetrically distributed relative to the center of the process hole. The process hole and the inner surface of the crankshaft hole are finely processed to form a first positioning surface and a second positioning surface for matching with the fixture.

2. The eccentric oscillating gear device according to claim 1, characterized in that: The swing gear includes a first swing gear and a second swing gear, and the first swing gear and the second swing gear are 180 degrees out of phase with each other.

3. The eccentric oscillating gear device according to claim 2, characterized in that: The clamp (13) has a base, on which are disposed two side positioning columns (131) and a center positioning column (132), the two side positioning columns being respectively a first side positioning column and a second side positioning column, the first side positioning column and the second side positioning column being respectively located on both sides of the center positioning column, and the first side positioning column, the center positioning column and the second side positioning column being in a straight line.

4. The eccentric oscillating gear device according to claim 3, characterized in that: The first swing gear (31) is sleeved on the fixture, and the first swing gear (31) is respectively positioned and matched with the first side positioning column and the center positioning column; the second swing gear (32) is sleeved on the fixture, and the second swing gear (32) is positioned and matched with the second side positioning column and the center positioning column.

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