RV speed reducer

Abstract

The invention is suitable for the field of cycloidal speed reducers, and provides an RV speed reducer which comprises a shell assembly, an input assembly and a speed reduction assembly and is characterized in that the shell assembly comprises a front supporting shell, a rear supporting shell, a positioning bolt and a positioning shaft, and the front supporting shell and the rear supporting shell are fixedly installed through the positioning bolt; positioning holes are annularly formed in the supporting front shell and the supporting rear shell, the positioning shaft is installed in the positioning holes in a rolling mode, the speed reduction assembly comprises a speed reduction sealing cover, a planet assembly and a main speed reduction assembly, the speed reduction sealing cover is installed in the supporting front shell through a bearing, and the circle center of the speed reduction sealing cover coincides with the circle center of the supporting front shell; and the kinetic energy transmission efficiency and the maximum running speed are improved, so that the joint is more suitable for high-speed robot speed reduction joints. Pitting corrosion, micro pitting corrosion and eccentric wear of the balance wheel are avoided, and the service life of the speed reduction assembly is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of cycloid reducers, and in particular relates to an RV reducer. Background Art

[0002] With the maturity of the industrial robot industry and the rise of the humanoid robot industry, reducers using the cycloid meshing reduction principle (cycloid pinwheel reducers, RV reducers, etc.) have been widely used in the market. Compared with its competitor, the harmonic reducer, it has higher rigidity, higher efficiency, and higher load capacity. Industrial robot manufacturers generally use it as the reducer for the first four joints of medium-load manipulators, or all six joints of heavy-load manipulators. The emerging humanoid robot industry also has a trend of replacing the reducers of large joints (hip, knee, shoulder, etc.) with non-backdrive harmonic reducers and cycloid pinwheel reducers due to the need for backdrive capability (specifically manifested as low starting torque and high efficiency) in the mechanical control algorithm.

[0003] The existing radial constraint method of the spacer is essentially a gasket, and there is tangential sliding friction between the spacer itself and the cycloid wheels on both sides. Considering that the radial load in the cycloid pinwheel reduction principle is extremely small, such sliding friction should be in the hydrodynamic lubrication regime, and the friction resistance is related to the contact area and relative angular velocity.

[0004] The invention patent CN201110130900.4 reduces the contact area with the cycloidal wheel contact surface by arranging annular grooves, reducing friction losses, but such radial constraint still has sliding friction, and its loss is much greater than rolling friction. This will reduce the operating efficiency of the reducer, increase the starting torque, affect the performance of the cycloidal pinwheel reducer at high speed, and limit its application in the field of high-speed robots. At the same time, since the annular grooves need to occupy a larger radial space, this will increase the size and weight of the reducer, affecting the application of the reducer in the field of robots that are sensitive to space, torque density and high-speed performance.

[0005] Even though the invention patent CN201110130900.4 uses wear-resistant nylon material to make the spacer, sliding friction will still wear the spacer and shorten the life of the reducer. At the same time, the generated debris enters the lubricant (oil, grease), further deteriorating the operating condition of the reducer. Summary of the invention

[0006] The present invention provides an RV reducer, aiming to solve the problems of short service life and low transmission efficiency of the existing RV reducer.

[0007] The present invention is implemented as follows: an RV reducer comprises a housing assembly, an input assembly and a reduction assembly, characterized in that: the housing assembly comprises a supporting front shell, a supporting rear shell, a positioning bolt and a positioning shaft, the supporting front shell and the supporting rear shell are fixedly installed by the positioning bolts, the supporting front shell and the supporting rear shell are annularly provided with positioning holes, the positioning shaft is rollingly installed in the positioning holes, the reduction assembly comprises a reduction cover, a planetary assembly and a main reduction assembly, the reduction cover is installed in the supporting front shell through a bearing and the center of the reduction cover coincides with the center of the supporting front shell, the input assembly comprises an input shaft and an input gear, the input shaft is installed at the center of the reduction cover through a bearing and the input shaft passes through the reduction cover, the input gear is installed on the end of the input shaft away from the reduction cover, the input gear is meshed with the planetary assembly, and the main reduction assembly is installed between the reduction cover and the planetary assembly.

[0008] Furthermore: the planetary assembly includes a first planetary gear, a second planetary gear and a third planetary gear, the first planetary gear, the second planetary gear and the third planetary gear are respectively engaged with the input gear, the first planetary gear is installed with a first planetary shaft, the second planetary gear is installed with a second planetary shaft, and the third planetary gear is installed with a third planetary shaft.

[0009] Furthermore: the main reduction assembly includes a power output disc, a first side balance wheel, a second side balance wheel, and a main balance wheel. The power output disc is mounted with the supporting rear shell and the input shaft through bearings. The first side balance wheel is provided with a first swing circular hole, the second side balance wheel is provided with a second swing circular hole, the main balance wheel is provided with a main swing circular hole, the first side balance wheel, the second side balance wheel, and the main balance wheel are all provided with pushing disc holes, and the first planetary shaft, the second planetary shaft, the third planetary shaft and the power output disc are mounted with bearings.

[0010] Furthermore: a driving shaft is arranged on the power output disc, and the driving shaft passes through the driving disc hole on the second side balance wheel, the driving disc hole on the main balance wheel, and the driving disc hole on the first side balance wheel in sequence along the direction from the supporting rear shell to the supporting front shell.

[0011] Furthermore: the first planetary shaft, the second planetary shaft and the third planetary shaft all pass through the power output disk, the second swing circular hole, the main swing circular hole and the first swing circular hole in sequence along the direction from the supporting rear shell to the supporting front shell; the first planetary shaft, the second planetary shaft and the third planetary shaft are installed in cooperation with the deceleration cover through bearings; the first planetary shaft, the second planetary shaft and the third planetary shaft are all formed with a second eccentric wheel, a main eccentric wheel and a first eccentric wheel along the direction from the supporting rear shell to the supporting front shell; bearings are installed on the outer sides of the second eccentric wheel, the main eccentric wheel and the first eccentric wheel, and the second eccentric wheel, the main eccentric wheel and the first eccentric wheel are located in the second swing circular hole, the main swing circular hole and the first swing circular hole.

[0012] Furthermore: a first sinker is arranged on the end face of the first side balance wheel away from the main balance wheel, a second sinker is arranged on the end face of the second side balance wheel away from the main balance wheel, main sinkers are arranged on both side end faces of the main balance wheel, and restraining balls are arranged in the main sinkers.

[0013] Furthermore, the outer contours of the first side balance wheel, the second side balance wheel and the main balance wheel are installed in cooperation with the positioning shaft.

[0014] The beneficial effects achieved by the present invention are as follows: when the first planetary shaft, the second planetary shaft and the third planetary shaft rotate, the first side balance wheel, the second side balance wheel and the main balance wheel perform cycloidal motion. When performing cycloidal motion, the positioning shaft radially constrains the first side balance wheel, the second side balance wheel and the main balance wheel. Secondly, the bearings on the first planetary shaft, the second planetary shaft and the third planetary shaft play an axial constraint role on each other, thereby preventing the first side balance wheel and the second side balance wheel from moving away from the main balance wheel. Secondly, a constraint ball is arranged in the main sink, and the friction form between the first side balance wheel, the second side balance wheel and the main balance wheel is rolling friction, and at the same time, axial constraints are exerted on the first side balance wheel, the second side balance wheel and the main balance wheel. Such a rolling friction support has extremely low friction loss and can withstand extremely high operating speeds, greatly reducing the starting torque and friction loss generated by the axial constraint of the cycloidal pinwheel reducer, improving its kinetic energy transfer efficiency and maximum operating speed, making it more suitable for high-speed robot deceleration joints. Secondly, since there is sliding friction between traditional balance wheels, there will be lubricant shear loss, but the present invention adopts the method of using constraint balls to achieve axial constraint to avoid eccentric wear of the cycloid wheel, thereby reducing pitting and micro-pitting of the cycloid wheel and increasing the life of the cycloid wheel. At the same time, reducing friction loss also helps to reduce the operating temperature of the reducer and increase the operating viscosity of the lubricant, thereby protecting the contact surface while avoiding the occurrence of hot glue and increasing the service life of the reduction component. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall first-view structure of the present invention; Figure 2 is a schematic diagram of the structure of the input component of the present invention from a second viewing angle; Figure 3 is a schematic structural diagram of a housing assembly of the present invention from a first viewing angle; Figure 4 It is a schematic structural diagram of the deceleration assembly of the present invention from a first perspective; Figure 5 is a schematic structural diagram of the deceleration assembly of the present invention from a second viewing angle; Figure 6 is a schematic structural diagram of the deceleration assembly of the present invention from a third viewing angle; Figure 7 is a schematic structural diagram of the deceleration assembly of the present invention from a fourth viewing angle; Figure 8 is a schematic structural diagram of the deceleration assembly of the present invention from a fifth viewing angle; Fig. 9 is a sixth perspective structural diagram of the deceleration assembly of the present invention; Fig.10 is a schematic structural diagram of the main balance wheel of the present invention from a first viewing angle; Fig.11 It is a quarter cross-sectional view of the overall structure of the present invention.

[0016] In the figure: 1, housing assembly; 2, input assembly; 3, reduction assembly; 101, support front housing; 102, support rear housing; 103, positioning bolt; 104, positioning shaft; 201, input shaft; 202, input gear; 301, reduction cover; 302, planetary assembly; 303, main reduction assembly; 304, first planetary gear; 305, second planetary gear; 306, third planetary gear; 307, first planetary shaft; 308, second planetary shaft ; 309, the third planetary shaft; 401, the power output disc; 402, the first side balance wheel; 403, the second side balance wheel; 404, the main balance wheel; 405, the first swing circular hole; 406, the second swing circular hole; 407, the main swing circular hole; 408, the driving shaft; 409, the second eccentric wheel; 410, the main eccentric wheel; 411, the first eccentric wheel; 501, the first sinker; 502, the second sinker; 503, the main sinker; 504, the constrained ball. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0018] Embodiment 1 Reference Figure 1-Figure 11 The present invention is an RV reducer, comprising a housing component 1, an input component 2 and a reduction component 3, characterized in that: the housing component 1 comprises a supporting front shell 101, a supporting rear shell 102, a positioning bolt 103 and a positioning shaft 104, the supporting front shell 101 and the supporting rear shell 102 are fixedly installed by the positioning bolt 103, the supporting front shell 101 and the supporting rear shell 102 are annularly provided with positioning holes, the positioning shaft 104 is rollingly installed in the positioning holes, the reduction component 3 comprises a reduction cover 301, a planetary component 302 and a main reduction component 303, the reduction The cover 301 is installed in the supporting front shell 101 through a bearing, and the center of the reduction cover 301 coincides with the center of the supporting front shell 101. The input assembly 2 includes an input shaft 201 and an input gear 202. The input shaft 201 is installed at the center of the reduction cover 301 through a bearing, and the input shaft 201 passes through the reduction cover 301. The input gear 202 is installed on the end of the input shaft 201 away from the reduction cover 301. The input gear 202 is meshed and installed with the planetary assembly 302. The main reduction assembly 303 is installed between the reduction cover 301 and the planetary assembly 302.

[0019] The planetary assembly 302 includes a first planetary gear 304, a second planetary gear 305 and a third planetary gear 306. The first planetary gear 304, the second planetary gear 305 and the third planetary gear 306 are respectively engaged with the input gear 202. The first planetary gear 304 is installed with a first planetary shaft 307, the second planetary gear 305 is installed with a second planetary shaft 308, and the third planetary gear 306 is installed with a third planetary shaft 309.

[0020] The main reduction assembly 303 includes a power output disc 401, a first side balance wheel 402, a second side balance wheel 403, and a main balance wheel 404. The power output disc 401 is mounted with the supporting rear housing 102 and the input shaft 201 through bearings. The first side balance wheel 402 is provided with a first swinging circular hole 405, the second side balance wheel 403 is provided with a second swinging circular hole 406, the main balance wheel 404 is provided with a main swinging circular hole 407, the first side balance wheel 402, the second side balance wheel 403, and the main balance wheel 404 are all provided with pushing disc holes, and the first planetary shaft 307, the second planetary shaft 308, and the third planetary shaft 309 are mounted with the power output disc 401 through bearings.

[0021] A driving shaft 408 is provided on the power output disc 401, and the driving shaft 408 passes through the driving disc hole on the second side balance wheel 403, the driving disc hole on the main balance wheel 404, and the driving disc hole on the first side balance wheel 402 in sequence along the direction from supporting the rear shell 102 to supporting the front shell 101.

[0022] The first planetary shaft 307, the second planetary shaft 308 and the third planetary shaft 309 are respectively penetrated through the power output disc 401, the second swing circular hole 406, the main swing circular hole 407 and the first swing circular hole 405 in the direction from supporting the rear shell 102 to supporting the front shell 101. The first planetary shaft 307, the second planetary shaft 308 and the third planetary shaft 309 are installed in cooperation with the deceleration cover 301 through bearings. The first planetary shaft 307, the second planetary shaft 308 and the third planetary shaft 309 are respectively formed with a second eccentric wheel 409, a main eccentric wheel 410 and a first eccentric wheel 411 in the direction from supporting the rear shell 102 to supporting the front shell 101. Bearings are installed on the outer sides of the second eccentric wheel 409, the main eccentric wheel 410 and the first eccentric wheel 411, and the second eccentric wheel 409, the main eccentric wheel 410 and the first eccentric wheel 411 are located in the second swing circular hole 406, the main swing circular hole 407 and the first swing circular hole 405. The bearing plays an axial restraining role on the input shaft, preventing the first-side balance wheel 402, the second-side balance wheel 403, and the main balance wheel 404 from moving away from each other.

[0023] A first sink 501 is provided on the end face of the first side balance wheel 402 away from the main balance wheel 404, a second sink 502 is provided on the end face of the second side balance wheel 403 away from the main balance wheel 404, main sinks 503 are provided on both side end faces of the main balance wheel 404, and restraint balls 504 are provided in the main sinks 503. The traditional friction pads are replaced with restraint balls 504 to provide better axial restraint for the first side balance wheel 402, the second side balance wheel 403, and the main balance wheel 404. Secondly, the friction type generated between the first side balance wheel 402, the second side balance wheel 403, and the main balance wheel 404 is sliding friction, which reduces the friction loss and heat generation of the reducer as a whole.

[0024] The torque is transmitted to the input shaft 201 through the power source, and the input shaft 201 drives the input gear 202 to rotate, thereby driving the first planetary gear 304, the second planetary gear 305 and the third planetary gear 306 to rotate and revolve around the input gear 202. The first planetary gear 304, the second planetary gear 305 and the third planetary gear 306 rotate, and at the same time drive the first planetary shaft 307, the second planetary shaft 308 and the third planetary shaft 309 to rotate. The second eccentric wheel 409, the main eccentric wheel 410 and the first eccentric wheel 411 on the first planetary shaft 307, the second planetary shaft 308 and the third planetary shaft 309 make eccentric motion around the first planetary shaft 307, the first side balance wheel 402, the second side balance wheel 403 and the main balance wheel 404 make cycloidal motion within the radial range of the positioning shaft 104, and at the same time, the driving shaft body 408 and the speed reduction cover 301 on the power output disk 401 make circular motion around the input shaft 201, and the output power source is transmitted by the power output disk 401.

[0025] When the first planetary shaft 307, the second planetary shaft 308 and the third planetary shaft 309 rotate, the first side balance wheel 402, the second side balance wheel 403 and the main balance wheel 404 perform cycloidal motion. When performing cycloidal motion, the positioning shaft 104 radially constrains the first side balance wheel 402, the second side balance wheel 403 and the main balance wheel 404. Secondly, the bearings on the first planetary shaft 307, the second planetary shaft 308 and the third planetary shaft 309 mutually constrain axially, thereby preventing the first side balance wheel 402 and the second side balance wheel 403 from moving away from the main balance wheel 404. Secondly, a constraining ball 504 is arranged in the main sink 503. The friction form between the first side balance wheel 402, the second side balance wheel 403 and the main balance wheel 404 is rolling friction, and the first side balance wheel 402, the second side balance wheel 403 and the main balance wheel 404 are axially constrained at the same time. Such rolling friction support has extremely low friction loss and can withstand extremely high operating speed. The starting torque and friction loss caused by the axial constraint of the cycloid pinwheel reducer are greatly reduced, and its kinetic energy transfer efficiency and maximum operating speed are improved, making it more suitable for high-speed robot deceleration joints. Secondly, since there is rolling friction between the balance wheels, pitting, micropitting and eccentric wear of the balance wheels are avoided, and the service life of the deceleration component 3 is increased.

[0026] Embodiment 2 Based on Example 1, refer to Figure 1-Figure 11 A first sinking platform 501 is provided on the end surface of the first side balance wheel 402 away from the main balance wheel 404, a second sinking platform 502 is provided on the end surface of the second side balance wheel 403 away from the main balance wheel 404, main sinking platforms 503 are provided on both side end surfaces of the main balance wheel 404, and restraining balls 504 are provided in the main sinking platforms 503. The outer contours of the first side balance wheel 402, the second side balance wheel 403 and the main balance wheel 404 are installed in cooperation with the positioning shaft 104.

[0027] The diameter of the constrained ball 504 is represented by d, the depth of the sink is represented by h, and the constrained gap between the two cycloid wheels is represented by L, and the relationship is expressed as: L=dh.

[0028] The diameter of the main sink is represented by D, and the eccentricity of the main balance wheel is represented by e. Since the constraint ball 504 revolves around the center of the main sink 503, the diameter D of the main sink should be equal to twice the eccentricity of the main balance wheel e plus the diameter d of the constraint ball 504, and finally add twice the constraint gap L to prevent the ball from touching the side wall of the sink. The diameter calculation of the main sink is represented by: D=2*e+d+2*L.

[0029] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An RV reducer, comprising a housing assembly (1), an input assembly (2) and a reduction assembly (3), characterized in that: The housing assembly (1) comprises a supporting front housing (101), a supporting rear housing (102), a positioning bolt (103) and a positioning shaft (104); the supporting front housing (101) and the supporting rear housing (102) are fixedly mounted via the positioning bolt (103); the supporting front housing (101) and the supporting rear housing (102) are provided with annular positioning holes in their interiors; the positioning shaft (104) is rollingly mounted in the positioning holes; the reduction assembly (3) comprises a reduction cover (301), a planetary assembly (302) and a main reduction assembly (303); the reduction cover (301) is mounted in the supporting front housing (101) via a bearing and the reduction shaft (104) is rollingly mounted in the planetary assembly (302). The cover (301) coincides with the center of the support front shell (101); the input assembly (2) comprises an input shaft (201) and an input gear (202); the input shaft (201) is mounted at the center of the reduction cover (301) via a bearing and the input shaft (201) passes through the reduction cover (301); the input gear (202) is mounted on an end of the input shaft (201) away from the reduction cover (301); the input gear (202) is meshed with the planetary assembly (302); and the main reduction assembly (303) is mounted between the reduction cover (301) and the planetary assembly (302).

2. The RV reducer according to claim 1, characterized in that: The planetary assembly (302) comprises a first planetary gear (304), a second planetary gear (305) and a third planetary gear (306); the first planetary gear (304), the second planetary gear (305) and the third planetary gear (306) are respectively engaged with the input gear (202); the first planetary gear (304) is mounted with a first planetary shaft (307), the second planetary gear (305) is mounted with a second planetary shaft (308), and the third planetary gear (306) is mounted with a third planetary shaft (309).

3. An RV reducer according to claim 2, characterized in that: The main reduction assembly (303) comprises a power output disc (401), a first side balance wheel (402), a second side balance wheel (403), and a main balance wheel (404); the power output disc (401) is mounted with the supporting rear housing (102) and the input shaft (201) via bearings; a first swinging circular hole (405) is provided on the first side balance wheel (402); a second swinging circular hole (406) is provided on the second side balance wheel (403); a main swinging circular hole (407) is provided on the main balance wheel (404); a pushing circular disc hole is provided on the first side balance wheel (402), the second side balance wheel (403), and the main balance wheel (404); and the first planetary shaft (307), the second planetary shaft (308), the third planetary shaft (309), and the power output disc (401) are mounted with bearings.

4. The RV reducer according to claim 3, characterized in that: The power output disc (401) is provided with a driving shaft (408), and the driving shaft (408) sequentially penetrates the driving disc hole on the second side balance wheel (403), the driving disc hole on the main balance wheel (404), and the driving disc hole on the first side balance wheel (402) along the direction from the supporting rear shell (102) to the supporting front shell (101).

5. The RV reducer according to claim 4, characterized in that: The first planetary shaft (307), the second planetary shaft (308) and the third planetary shaft (309) are sequentially passed through the power output disc (401), the second swing circular hole (406), the main swing circular hole (407) and the first swing circular hole (405) along the direction from the supporting rear shell (102) to the supporting front shell (101); the first planetary shaft (307), the second planetary shaft (308) and the third planetary shaft (309) are mounted in cooperation with the speed reduction cover (301) via bearings; the first planetary shaft (307), the second planetary shaft (308) and the third planetary shaft (309) are mounted in cooperation with the speed reduction cover (301) via bearings; the first planetary shaft (307), the second planetary shaft (308) and the third planetary shaft (309) are mounted in cooperation with the speed reduction cover (301) via bearings; the first planetary shaft (307), the second planetary shaft (30 8) and the third planetary shaft (309) are formed with a second eccentric wheel (409), a main eccentric wheel (410) and a first eccentric wheel (411) along the direction from the supporting rear shell (102) to the supporting front shell (101), and bearings are installed on the outer sides of the second eccentric wheel (409), the main eccentric wheel (410) and the first eccentric wheel (411), and the second eccentric wheel (409), the main eccentric wheel (410) and the first eccentric wheel (411) are located in the second swing circular hole (406), the main swing circular hole (407) and the first swing circular hole (405).

6. The RV reducer according to claim 3, characterized in that: A first sinking platform (501) is arranged on an end surface of the first side balance wheel (402) away from the main balance wheel (404), a second sinking platform (502) is arranged on an end surface of the second side balance wheel (403) away from the main balance wheel (404), main sinking platforms (503) are arranged on both side end surfaces of the main balance wheel (404), and a restraining ball (504) is arranged inside the main sinking platform (503).

7. The RV reducer according to claim 3, characterized in that: The outer contours of the first side balance wheel (402), the second side balance wheel (403) and the main balance wheel (404) are mounted in cooperation with the positioning shaft (104).

Images