Bearing pre-tightening structure of RV speed reducer

Abstract

The utility model provides an RV reducer bearing pre-tightening structure, which relates to the technical field of RV reducer assembly, and comprises a pin wheel housing, a planet carrier, an input gear shaft, a bearing I, a bearing II, a shaft circlip and a waveform elastic piece, two bearing holes are formed in the side, facing the input gear shaft, of the planet carrier, outer rings of the first bearing and the second bearing are pressed into the different bearing holes respectively, and inner rings of the first bearing and the second bearing are pressed on the outer wall of the input gear shaft respectively. The wave-shaped elastic piece is arranged between the outer ring of the first bearing and the planet carrier, is located at the bottom of the bearing hole and is attached to the planet carrier; a clamping spring groove adjacent to the first bearing is formed in the outer wall of the input gear shaft, and the shaft elastic check ring is embedded in the clamping spring groove and located on the side, away from the wave-shaped elastic piece, of the first bearing. The bearing pre-tightening device solves the problems caused by the fact that a conventional plane gasket is adopted for bearing pre-tightening, improves product production efficiency and reduces production cost.

Description

Technical Field

[0001] The utility model relates to the technical field of RV reducers, and in particular to a bearing pre-tightening structure for RV reducers. Background Art

[0002] RV reducers have compact structure, small size, light weight, large transmission ratio, high rigidity, smooth starting, accurate positioning, and strong controllability. They are widely used in industrial robots, machine tools, medical testing equipment and other fields to achieve precise transmission of motion and instructions and complete precise and complex work.

[0003] The RV reducer adopts two-stage reduction. The first stage reduction adopts involute cylindrical gear planetary reduction. The active sun gear is connected to the input shaft. If the sun gear rotates clockwise, it will drive the planetary gears evenly distributed along its circumference to revolve around the sun gear axis while rotating counterclockwise. Each planetary gear is fixedly connected to its own crankshaft so that the crankshaft rotates at the same speed, and the crankshaft becomes the input shaft of the second stage. The second stage adopts a cycloid pinwheel reduction mechanism. The eccentric part of the crankshaft is installed with the RV cycloid wheel through the bearing. The circumference of the RV cycloid wheel is provided with needle teeth with one more tooth number than the RV cycloid wheel. The needle teeth are meshed with the RV cycloid wheel. The needle teeth are arranged with the same pitch as the RV cycloid wheel, and the needle teeth are set in the needle gear housing. When the pinion gear case is fixedly transmitted, since the RV cycloid wheel is installed on the eccentric part of the crankshaft, the crankshaft rotates counterclockwise, and the RV cycloid wheel rotates clockwise, pushing the crankshaft to drive the planetary carrier to rotate clockwise. During this process, the RV cycloid wheel continuously engages and disengages with the pinion teeth.

[0004] The existing RV reducer input gear shaft installation methods mainly include no bearing support, single bearing support, and double bearing support. Different installation methods are selected according to the application and working conditions. The input gear shaft double bearing support is mainly used in the case where the motor is offset and the power is transmitted through the pulley. The motor offset transmits power through the pulley, which will generate a radial force on the input gear shaft. Therefore, the bearings at both ends of the input gear shaft must be properly preloaded, otherwise the reducer will generate noise or abnormal sound when it is under force, affecting product performance.

[0005] The existing method of preloading the bearings at both ends of the input gear shaft mainly adopts the method of selecting a flat gasket of appropriate thickness to ensure the appropriate axial interference, that is, according to the calculation of the dimension chain, flat gaskets of different thickness specifications are selected, and the thickness interval of each specification of flat gasket is about 0.01mm. In order to ensure the appropriate preload force of the bearing, the thickness specifications of the flat gaskets are required to be as few as a dozen, and as many as thirty or forty. Before selecting the flat gasket, the relevant assembly dimensions of the gasket must be fully measured. This method of selecting a flat gasket of appropriate thickness to preload the bearing reduces production efficiency and increases production costs.

[0006] Therefore, there is room for improvement, and the utility model provides a structure for pre-tightening the bearing of an RV reducer. Utility Model Content

[0007] In view of the shortcomings of the prior art, the utility model aims to propose a structure for pre-tightening the bearing of an RV reducer. The specific scheme is as follows:

[0008] A bearing pre-tightening structure for an RV reducer, the structure comprising a pinion housing, a planet carrier, an input gear shaft, a first bearing, a second bearing, a shaft elastic retaining ring, and a wave elastic member;

[0009] The pinion gear housing, the planet carrier, and the input gear shaft are coaxially arranged from outside to inside in sequence;

[0010] The planet carrier is provided with two bearing holes spaced apart on one side facing the input gear shaft, the outer rings of the first bearing and the second bearing are respectively pressed into different bearing holes, and the inner rings of the first bearing and the second bearing are respectively pressed onto the outer wall of the input gear shaft;

[0011] The corrugated elastic member is arranged between the outer ring of the bearing 1 and the planet carrier, and the corrugated elastic member is located at the bottom of the bearing hole and is arranged in close contact with the planet carrier;

[0012] The outer wall of the input gear shaft is provided with a retaining ring groove adjacent to the bearing one, the shaft elastic retaining ring is embedded in the retaining ring groove, and the shaft elastic retaining ring is located at the side of the bearing one away from the corrugated elastic member.

[0013] Furthermore, the wave elastic member is a wave spring or a wave gasket.

[0014] Furthermore, the first bearing and the second bearing are deep groove ball bearings, tapered roller bearings or angular contact bearings.

[0015] Furthermore, the corrugated elastic member is made of 60Si2MnA or 50CrVA.

[0016] Furthermore, the thickness of the corrugated elastic member is in the range of 0.3 mm to 1.4 mm, the waveform curve of the corrugated elastic member refers to a sine curve, each wave crest is evenly distributed along the circumference, and the number of waveforms is 3-7.

[0017] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0018] (1) Compared with the existing method, the bearing preload method of this structure eliminates the need to measure the relevant assembly dimensions before assembly, and only requires one corrugated elastic member, which is wavy along its circumferential direction. During the bearing preload process, the corrugated elastic member has a certain adaptive adjustment ability and can replace flat gaskets of different thickness specifications. This solves the problem that the bearing preload needs to first measure the assembly dimensions of different parts and then select flat gaskets of different thickness specifications, reduces the requirements for part processing tolerances, thereby improving product production efficiency and reducing production costs, and simplifies the management of gasket specifications and the assembly process.

[0019] (2) By providing a shaft elastic retaining ring, the shaft elastic retaining ring has a limiting effect on the bearing, thereby ensuring the stability between the bearing and the corrugated elastic member. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a partial cross-sectional schematic diagram showing details of the utility model;

[0021] Figure 2 A schematic diagram of a wave spring used as a wave elastic member;

[0022] Figure 3 Schematic diagram of using corrugated gasket for corrugated elastic member.

[0023] Figure numerals: 1, pin gear housing; 2, planet carrier; 3, bearing 1; 4, elastic retaining ring for shaft; 5, input gear shaft; 6, wave elastic member; 7, bearing 2; 8, bearing hole; 9, retaining ring groove. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below in conjunction with the embodiments and drawings, but the implementation methods of the present invention are not limited thereto.

[0025] In view of the installation method of the double-bearing support of the input gear shaft 5 of the RV reducer, the utility model proposes a bearing pre-tightening structure of the RV reducer, which is convenient for simplifying the bearing pre-tightening process during the production process.

[0026] It should be noted that the above structure is for several steps in the installation process of the RV reducer input gear shaft 5, so it will involve certain components in the RV reducer. For other components not involved in the RV reducer, the utility model will not go into too much detail.

[0027] Specifically, if Figure 1This structure includes a pinion housing 1, a planet carrier 2, an input gear shaft 5, a bearing 1 3, a bearing 2 7, a shaft elastic retaining ring 4, and a wave elastic member 6. According to the design requirements of the RV reducer, the pinion housing 1, the planet carrier 2, and the input gear shaft 5 all adopt conventional technology, and the bearing 1 3 and the bearing 2 7 adopt deep groove ball bearings, tapered roller bearings or angular contact bearings, such as Figure 2 , 3 As shown, the wave elastic member 6 is a wave spring or a wave gasket.

[0028] It should be noted that the wave gasket is generally a single-layer structure, and the wave spring is generally a regularly arranged multi-layer structure. The specific number of layers is set according to needs and is not specifically limited.

[0029] It should be noted that the corrugated elastic member 6 is made of 60Si2MnA or 50CrVA to have good elasticity. Other materials may also be used without specific limitation.

[0030] It should be noted that the thickness of the corrugated elastic member 6 is in the range of 0.3 mm to 1.4 mm, the waveform curve of the corrugated elastic member refers to a sine curve, each wave crest is evenly distributed along the circumference, and the number of waves is 3-7.

[0031] The planet carrier 2 is provided with two bearing holes 8 spaced apart on one side facing the input gear shaft 5. During installation, first, the outer ring of the bearing 2 7 is pressed into the corresponding bearing hole 8 of the planet carrier 2. Then, the wave elastic member 6 and the outer ring of the bearing 1 3 are installed into the corresponding bearing hole 8 of the planet carrier 2. At this time, the wave elastic member 6 is arranged between the outer ring of the bearing 1 3 and the planet carrier 2, and the wave elastic member 6 is at the bottom of the bearing hole 8 and is arranged in close contact with the planet carrier 2.

[0032] Afterwards, the inner ring of the bearing 2 7 is press-fitted onto the input gear shaft 5 , and the input gear shaft 5 with the inner ring of the bearing 2 7 press-fitted thereon is installed onto the planet carrier 2 .

[0033] Afterwards, the outer ring of the bearing 3 and the corrugated elastic member 6 are pre-tightened using a special tool, and the inner ring of the bearing 3 is pressed onto the input gear shaft 5.

[0034] A retaining ring groove 9 is provided on the outer wall of the input gear shaft 5 and is adjacent to the bearing 3. Then, the shaft elastic retaining ring 4 is installed on the retaining ring groove 9 of the input gear shaft 5. It can be seen that the shaft elastic retaining ring 4 is embedded in the retaining ring groove 9, and the shaft elastic retaining ring 4 is located on the side of the bearing 3 away from the corrugated elastic member 6.

[0035] After completing the above steps, it can be seen that in the bearing pre-tightening structure of the RV reducer of the present invention, the pinion housing 1, the planetary carrier 2, and the input gear shaft 5 are coaxially arranged from the outside to the inside in sequence, and the outer rings of the bearing 1 3 and the bearing 2 7 are respectively pressed into different bearing holes 8, and the inner rings of the bearing 1 3 and the bearing 2 7 are respectively pressed onto the outer wall of the input gear shaft 5, so that the input gear shaft 5 is installed on the planetary carrier 2 through the bearings at both ends.

[0036] Based on the RV reducer bearing preload structure, only one specification of corrugated elastic member 6 is used to replace flat gaskets of different thicknesses, thereby solving the problem that the bearing preload needs to first measure the assembly dimensions of different parts and then select flat gaskets of different thicknesses, thereby reducing the requirements for part processing tolerances, improving production efficiency and reducing production costs.

[0037] The above is only a preferred embodiment of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A bearing preload structure for an RV reducer, characterized in that: The structure comprises a pinion housing (1), a planet carrier (2), an input gear shaft (5), a first bearing (3), a second bearing (7), a shaft elastic retaining ring (4), and a wave elastic member (6); The pin gear housing (1), the planet carrier (2), and the input gear shaft (5) are coaxially arranged in sequence from outside to inside; Two bearing holes (8) are arranged at intervals on one side of the planet carrier (2) facing the input gear shaft (5); the outer rings of the first bearing (3) and the second bearing (7) are respectively pressed into different bearing holes (8); and the inner rings of the first bearing (3) and the second bearing (7) are respectively pressed into the outer wall of the input gear shaft (5); The corrugated elastic member (6) is arranged between the outer ring of the bearing 1 (3) and the planet carrier (2), and the corrugated elastic member (6) is located at the bottom of the bearing hole (8) and is arranged in close contact with the planet carrier (2); The outer wall of the input gear shaft (5) is provided with a retaining ring groove (9) arranged adjacent to the bearing one (3), the shaft elastic retaining ring (4) is embedded in the retaining ring groove (9), and the shaft elastic retaining ring (4) is located on the side of the bearing one (3) away from the corrugated elastic member (6).

2. The RV reducer bearing preload structure according to claim 1 is characterized in that: The wave elastic member (6) is a wave spring or a wave gasket.

3. The RV reducer bearing preload structure according to claim 1, characterized in that: The bearing 1 (3) and the bearing 2 (7) are deep groove ball bearings, tapered roller bearings or angular contact bearings.

4. The RV reducer bearing preload structure according to claim 2 is characterized in that: The corrugated elastic member (6) is made of 60Si2MnA or 50CrVA.

5. The RV reducer bearing preload structure according to claim 2, characterized in that: The thickness of the corrugated elastic member (6) ranges from 0.3 mm to 1.4 mm, the corrugated curve of the corrugated elastic member (6) refers to a sine curve, each wave crest is evenly distributed along the circumference, and the number of waves is 3 to 7.

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