CN109262076B

CN109262076B - Efficient precision grinding machining method for RV cycloidal gear

Info

Publication number: CN109262076B
Application number: CN201811147697.XA
Authority: CN
Inventors: 陈永洪; 陈兵奎; 罗文军; 李朝阳; 郑正鼎
Original assignee: Chongqing University
Current assignee: Chongqing University
Priority date: 2018-09-29
Filing date: 2018-09-29
Publication date: 2020-04-10
Anticipated expiration: 2038-09-29
Also published as: CN109262076A

Abstract

The invention discloses a high-efficiency precise grinding processing method for RV cycloid gears, which is characterized in that a plurality of grinding head assemblies uniformly distributed in the circumferential direction of a series of cycloid gears perform full-enveloping seamless grinding on the series of cycloid gears, the grinding head assemblies move up and down to form grinding feed motion, and then the one-time seamless full-enveloping high-efficiency grinding on tooth profiles of the series of cycloid gears is completed. The invention realizes the one-time full-enveloping seamless grinding processing of the series cycloid gear and fundamentally solves the problems of low processing precision and low processing efficiency in the processing process of the tooth profile of the cycloid gear at present.

Description

Efficient precision grinding machining method for RV cycloidal gear

Technical Field

The invention belongs to the technical field of grinding methods, and particularly relates to a high-efficiency precise grinding method for an RV cycloidal gear.

Background

The RV reducer is a closed differential gear train consisting of an involute cylindrical gear planetary reduction mechanism and a cycloid pin wheel planetary reduction mechanism, has the advantages of small size, strong impact resistance, high torsional rigidity, high positioning precision, small vibration, large reduction ratio and the like, and is widely applied to the fields of industrial robots, medical detection equipment, aerospace, national defense weaponry and the like.

The planetary transmission multi-tooth meshing effect of the cycloid pin gear of the RV reducer brings extremely high machining precision requirements and assembling process requirements to the cycloid gear. At present, the machining of cycloid gears in RV reducers in China mostly adopts a forming and grinding machining principle of single-tooth indexing, the defects of poor machining precision, low machining efficiency and the like exist, and the large-scale production is severely restricted by machining equipment.

Therefore, how to solve the above-mentioned drawbacks of the prior art becomes the direction of efforts of those skilled in the art.

Disclosure of Invention

The invention aims to provide a high-efficiency and precise grinding method for an RV cycloid gear, which can completely solve the technical problems of low machining precision, low machining efficiency and the like in the process of machining the tooth profile of the cycloid gear.

The purpose of the invention is realized by the following technical scheme:

a high-efficiency precision grinding machining method for an RV cycloid gear comprises a machine tool, wherein the machine tool comprises a base, a first upright post, a second upright post, an indexing worktable, a cross beam and a mandrel; the first upright post and the second upright post are vertically fixed on two sides of the top surface of the base, the cross beam is horizontally arranged between the first upright post and the second upright post, two ends of the cross beam are correspondingly connected with the first upright post and the second upright post in a sliding way, and the cross beam can freely move along the vertical direction; a cross beam hole is formed in the cross beam, a plurality of grinding head assemblies are arranged in the cross beam hole along the circumferential direction, and the plurality of grinding head assemblies are combined to form a toroidal grinding surface; the indexing worktable is rotatably arranged on the top surface of the base corresponding to the beam hole; first or the detachable installation cantilever in second stand top, the free end bottom surface of cantilever is equipped with the sleeve, and the dabber bottom is the round platform, and this round platform is detachable to be installed on the index table, and the top passes behind the crossbeam hole the cooperation in the sleeve, just the dabber top is equipped with a screw thread section, is equipped with nut, its characterized in that on this screw thread section:

the series cycloid gears are overlapped and sleeved on the mandrel, the bottom ends of the series cycloid gears are limited by the round tables, the top ends of the series cycloid gears are locked by the nuts, a plurality of grinding head assemblies which are uniformly distributed in the circumferential direction of the series cycloid gears carry out full-enveloping seamless grinding on the series cycloid gears, and the grinding head assemblies are driven by the cross beam to move up and down to form grinding feeding motion.

Further, the bistrique subassembly is 2 layers at least, including upper bistrique subassembly and lower floor's bistrique subassembly, upper bistrique subassembly and lower floor's bistrique subassembly dislocation set form the planar grinding face of ring jointly each other.

Further, the grinding head assembly comprises a grinding wheel motor, a ring surface forming grinding wheel, a first guide rail, a second guide rail and a telescopic driving mechanism; an inner cavity is formed in the beam corresponding to each grinding head assembly, one ends of the first guide rail and the second guide rail extend into the inner cavity and are in single-degree-of-freedom sliding fit with the beam, and the telescopic driving mechanism is installed in the inner cavity, is connected with the first guide rail and the second guide rail and is used for driving the two guide rails to slide synchronously; the grinding wheel motor is fixed at the extending end of the first guide rail or the second guide rail, an output shaft of the grinding wheel motor is fixed at the extending end of the other guide rail through a bearing, and the ring surface molding grinding wheel is arranged on the output shaft of the grinding wheel motor;

the grinding wheel motor drives the ring surface forming grinding wheel to rotate to form grinding main motion; the ring surface forming grinding wheel moves along the radial direction of the cycloid gear to adjust the grinding amount.

Further, the ring surface forming grinding wheel is dressed by adopting a dressing assembly, the dressing assembly comprises a dressing motor, a diamond dressing roller and a mounting table, the bottom end of the mounting table is a round table, a fixing groove is formed in the bottom of the round table along the circumferential direction, a heightening block is arranged on the top surface of the round table, a pair of supports are arranged on the top surface of the heightening block, the dressing motor is fixed on the supports, and the diamond dressing roller is mounted on an output shaft of the dressing motor;

before dressing, a series of cycloid gears and a mandrel are taken down, a mounting table is fixed on an indexing table, a cross beam drives a torus forming grinding wheel to move up and down to form dressing feeding motion, a dressing motor drives a diamond dressing roller to rotate, the diamond dressing roller dresses a torus forming grinding wheel single tooth groove, the indexing table drives the diamond dressing roller to rotate horizontally, and dressing of all tooth grooves of the same torus forming grinding wheel and dressing of all tooth grooves of other torus forming grinding wheels are completed.

Further, the grinding wheel motor drives the ring surface forming grinding wheel to rotate to form dressing auxiliary motion.

Furthermore, the torus forming grinding wheel moves close to or away from the diamond dressing roller, so that the dressing amount is adjusted.

Compared with the prior art, the invention has the beneficial effects that: the method can accurately control the tooth profile precision of the torus forming grinding wheel and the phase precision of the tooth profiles, realizes the one-time full-enveloping seamless grinding processing of the series of cycloid gears, can fundamentally solve the problems of low processing precision and low processing efficiency in the existing cycloid gear tooth profile processing process, and has wide application value and universality of principle.

Drawings

FIG. 1 is a schematic perspective view of a machine tool according to the present invention;

fig. 2 is a schematic view showing the distribution of the grinding head assemblies in the present invention;

fig. 3 is a schematic structural view of a grinding head assembly according to the present invention;

FIG. 4 is a first schematic view of the driving structure of the index table of the present invention;

FIG. 5 is a second schematic view of the driving structure of the index table of the present invention;

FIG. 6 is a schematic view of a driving structure of the cross member in the present invention;

FIG. 7 is a schematic structural view of a conditioning assembly of the present invention;

FIG. 8 is a schematic perspective view of the process of the present invention;

FIG. 9 is a top view of FIG. 8;

FIG. 10 is a schematic representation of a torus forming wheel dressing.

Detailed Description

The invention will be further described with reference to specific embodiments and the accompanying drawings.

As shown in fig. 1 to 10, a high-efficiency precision grinding method for an RV cycloidal gear comprises a machine tool, which comprises a base 1, a first upright 2, a second upright 3, an indexing table 4, a cross beam 5 and a mandrel 6.

The first and second

upright columns

2 and 3 are vertically fixed on two sides of the top surface of the base 1, the crossbeam 5 is horizontally arranged between the first and second

upright columns

2 and 3, dovetail grooves are formed in two ends of the crossbeam 5, vertical guide rails matched with the dovetail grooves are vertically arranged on the first and second

upright columns

2 and 3, and the crossbeam 5 is in sliding fit with the vertical guide rails through the dovetail grooves so that the crossbeam 5 can freely move along the vertical direction. A beam hole 7 is formed in the beam 5, a plurality of grinding head assemblies 8 are arranged in the beam hole 7 along the circumferential direction, and the plurality of grinding head assemblies 8 are combined to form an annular grinding surface, which is shown in fig. 2.

In this embodiment, the lifting movement of the cross beam 5 is completed by the ball screw drive. The interior of the second upright post 3 is of a cavity structure, a motor 9 is arranged at the top of the cavity, the output end of the motor 9 is fixedly connected with a screw rod 10, and two ends of the screw rod 10 are arranged on the inner wall of the cavity of the second upright post 3 through bearings; the screw rod 10 is matched with a ball nut 11 to form a ball screw kinematic pair, and the cross beam 5 is fixedly connected with the ball nut 11. The screw rod 10 is driven by the motor 9 to rotate, and the cross beam 5 is driven to move up and down through the ball nut 11, see fig. 6.

In this embodiment, bistrique subassembly 8 is 2 layers, including upper bistrique subassembly and lower floor's bistrique subassembly, and upper bistrique subassembly and lower floor's bistrique subassembly include four bistrique subassemblies 8 respectively, upper bistrique subassembly and lower floor's bistrique subassembly dislocation set form the planar grinding face of ring jointly each other, refer to fig. 2.

Referring to fig. 3, the grinding head assembly 8 includes a grinding wheel motor 81, a torus shaped grinding wheel 82, a first guide rail 83, a second guide rail 84, and a telescopic driving mechanism. The beam 5 is provided with an inner cavity 12 corresponding to each grinding head assembly 8, one end of each of the first and

second guide rails

83, 84 extends into the inner cavity 12 and is in single-degree-of-freedom sliding fit with the beam 5 through a rectangular sliding bearing 85, and the telescopic driving mechanism is installed in the inner cavity 12 and is connected with the first and

second guide rails

83, 84 and used for driving the two guide rails to slide synchronously. The grinding wheel motor 81 is fixed at the overhanging end of the first guide rail 83, the output shaft of the grinding wheel motor 81 is fixed at the overhanging end of the second guide rail 84 through a precision rolling bearing, and the torus molding grinding wheel 82 is installed on the output shaft of the grinding wheel motor 81. The matching surface between the torus forming grinding wheel 82 and the output shaft of the grinding wheel motor 81 is a conical surface, and the output shaft of the grinding wheel motor 81 is in threaded connection with a nut 86 for axially locking the torus forming grinding wheel 82, so that the structure can play the roles of automatic centering and pressing.

The telescopic driving mechanism comprises a grinding head driving motor 88, a worm gear 87 and a gear set, wherein racks 89 are arranged on opposite sides of the inner extending ends of the first guide rail 83 and the second guide rail 84, the gear set is arranged between the two racks 89, the gear set comprises 4 gears 90 which are arranged side by side and meshed in a precise backlash-free mode, the gears 90 positioned on two outer sides are respectively meshed with the corresponding racks 89, an output shaft of the grinding head driving motor 88 is a worm 91, the worm 91 is matched with the worm gear 87 to form a worm gear mechanism, one gear 90 in the gear set is coaxially connected with the worm gear 87, the worm gear 87 and the worm 91 are in transmission to have a self-locking function, and the stability of the annular surface forming grinding wheel 82 in the grinding process is. The gear set is matched with 2 teeth 89 to ensure that the first guide rail 83 and the second guide rail 84 advance and retreat synchronously, thereby ensuring the uniformity of the dressing amount in the process of dressing the torus forming grinding wheel 82.

Referring to fig. 4 and 5, the index table 4 is rotatably installed on the top surface of the base 1 corresponding to the beam hole 7. Specifically, the base 1 is internally provided with an installation cavity, an indexing motor 13, a large-speed-ratio precise indexing worm wheel 14 and an indexing worm 15 are installed in the installation cavity, the indexing motor 13 drives the indexing worm 15, the large-speed-ratio precise indexing worm wheel 14 is meshed with the indexing worm 15, the large-speed-ratio precise indexing worm wheel 14 is fixed on the base 1 through a precise turntable bearing, the indexing worm 15 is fixed on the base 1 through a precise bearing, and the large-speed-ratio precise indexing worm wheel 14 is coaxially connected with the indexing worktable 4. When the rotary indexing mechanism works, the indexing motor 13 drives the indexing table 4 to rotate through the worm gear mechanism, and the indexing table 4 cannot automatically rotate when the indexing motor 13 does not work because a transmission pair formed by the indexing worm gear 14 and the indexing worm 15 has the self-locking property of reverse driving. The top surface of the indexing table 4 is provided with scales (not shown in the figure) for indexing, T-shaped grooves are uniformly arranged along the circumferential direction, sliding blocks are matched in the T-shaped grooves, threaded columns are vertically arranged on the sliding blocks, locking nuts are matched on the threaded columns, and a central positioning hole is formed in the center of the top surface of the indexing table.

The detachable installation cantilever 16 in 3 tops of second stand, the free end bottom surface of cantilever 16 is equipped with

sleeve

17, and 6 bottoms of dabber are the round platform, and this round platform is detachable installs on index table 4, and the cooperation is in sleeve 17 after 6 tops of dabber pass crossbeam hole 7, just 6 tops of dabber are equipped with a screw thread section, are equipped with nut 18 on this screw thread section. The bottom of the circular truncated cone is circumferentially provided with a fixing groove, and the mandrel 6 is fixed on the indexing table 4 by using a locking nut on the indexing table 4. The bottom surface of the circular truncated cone is provided with a positioning boss which is matched with a central positioning hole on the indexing table, and the mandrel carries out accurate centering and positioning by utilizing the central positioning hole and the sleeve.

The specific processing process is as follows:

the series cycloid gears 19 are overlapped and sleeved on the mandrel 6, the bottoms of the cycloid gears 19 are limited by a circular truncated cone at the bottom end of the mandrel 6, and the tops of the cycloid gears are compressed by nuts 18. In the grinding process of the cycloid gear 19, eight grinding wheel motors 81 drive eight torus forming grinding wheels 82 to rotate at a high speed to form a grinding main motion; the beam 5 drives the whole grinding head assembly 8 to move along the vertical direction to form grinding feed motion, and then the one-time full-enveloping seamless grinding processing of the series cycloid gears 19 on the mandrel 6 is completed. The torroidal shaping grinding wheel 82 is moved radially along the cycloidal gear to adjust the amount of grinding, see fig. 8 and 9.

The tooth profile precision of the torus forming grinding wheel 82 in the grinding head assembly 8 and the phase precision of the tooth profiles can be accurately controlled, the disposable full-enveloping seamless grinding processing of the series of cycloid gear gears is realized, the problems of low processing precision and low processing efficiency in the existing cycloid gear tooth profile processing process can be fundamentally solved, and the method has wide application value and universality of principle.

After long-term operation, the formed annular grinding wheel 82 is worn to some extent, and therefore, the invention also prepares a dressing assembly. The trimming assembly comprises a trimming motor 20, a diamond trimming roller 21 and a mounting table 22, the mounting table is a circular table, a fixing groove is formed in the bottom of the circular table along the circumferential direction, a padding block 23 is arranged on the top surface of the circular table, a pair of supports 24 are arranged on the top surface of the padding block 23, the trimming motor 20 is fixed on the supports 24, and the diamond trimming roller 21 is mounted on an output shaft of the trimming motor 20, as shown in fig. 7.

When the forming annular grinding wheel 82 needs to be dressed, the mandrel 6 is detached, the mounting table 22 is fixed on the indexing table 4, the bottom surface of the mounting table 22 is provided with a positioning boss, the positioning boss is matched with a central positioning hole in the indexing table 4 to realize positioning, and the mounting table 22 is fixed on the indexing table 4 through a locking nut. The grinding head driving motor 88 drives the first guide rail 83 and the second guide rail 84 to synchronously move outwards through a worm gear mechanism, so that the 8 ring surface forming grinding wheels 82 move slightly towards the center, and the adjustment of the finishing amount is realized. The dressing motor 20 drives the diamond dressing roller 21 to rotate at a high speed to form a dressing main motion, and 8 grinding wheel motors 81 drive 8 annular surface forming grinding wheels 82 to rotate to form a dressing auxiliary motion. The beam 5 drives the whole grinding head assembly 8 to vertically move to form finishing feed movement, after finishing one tooth side, the indexing worktable 4 precisely indexes to drive the forming diamond finishing roller 21 to index, so that finishing of the next tooth socket is realized until finishing of all tooth sockets; thereby realizing the precise trimming of the tooth profile of the eight torus forming grinding wheels and the precise control of the phase of the tooth profile.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A high-efficiency precision grinding machining method for an RV cycloid gear comprises a machine tool, wherein the machine tool comprises a base, a first upright post, a second upright post, an indexing worktable, a cross beam and a mandrel; the first upright post and the second upright post are vertically fixed on two sides of the top surface of the base, the cross beam is horizontally arranged between the first upright post and the second upright post, two ends of the cross beam are correspondingly connected with the first upright post and the second upright post in a sliding way, and the cross beam can freely move along the vertical direction; a cross beam hole is formed in the cross beam, a plurality of grinding head assemblies are arranged in the cross beam hole along the circumferential direction, and the plurality of grinding head assemblies are combined to form a toroidal grinding surface; the indexing worktable is rotatably arranged on the top surface of the base corresponding to the beam hole; first or the detachable installation cantilever in second stand top, the free end bottom surface of cantilever is equipped with the sleeve, and the dabber bottom is the round platform, and this round platform is detachable to be installed on the index table, and the dabber top passes behind the crossbeam hole the cooperation in the sleeve, just the dabber top is equipped with a screw thread section, is equipped with nut, its characterized in that on this screw thread section:

the series of cycloid gears are overlapped and sleeved on the mandrel, the bottom ends of the series of cycloid gears are limited by the round tables, the top ends of the series of cycloid gears are locked by nuts, a plurality of grinding head assemblies which are uniformly distributed in the circumferential direction of the series of cycloid gears carry out full-enveloping seamless grinding on the series of cycloid gears, and the grinding head assemblies are driven by the cross beam to move up and down to form grinding feeding motion.

2. The high-efficiency precision grinding method for the RV cycloid gear according to claim 1, characterized in that: the grinding head assembly is at least 2 layers and comprises an upper layer grinding head assembly and a lower layer grinding head assembly, and the upper layer grinding head assembly and the lower layer grinding head assembly are mutually arranged in a staggered mode to form a grinding surface of a ring surface shape.

3. The high-efficiency precision grinding method for the RV cycloid gear according to claim 2, characterized in that: the grinding head assembly comprises a grinding wheel motor, a ring surface forming grinding wheel, a first guide rail, a second guide rail and a telescopic driving mechanism; an inner cavity is formed in the beam corresponding to each grinding head assembly, one ends of the first guide rail and the second guide rail extend into the inner cavity and are in single-degree-of-freedom sliding fit with the beam, and the telescopic driving mechanism is installed in the inner cavity, is connected with the first guide rail and the second guide rail and is used for driving the two guide rails to slide synchronously; the grinding wheel motor is fixed at the extending end of the first guide rail or the second guide rail, an output shaft of the grinding wheel motor is fixed at the extending end of the other guide rail through a bearing, and the ring surface molding grinding wheel is arranged on the output shaft of the grinding wheel motor;

4. The high-efficiency precision grinding method for the RV cycloid gear according to any one of claims 1 to 3, characterized by comprising: the ring surface forming grinding wheel is dressed by adopting a dressing assembly, the dressing assembly comprises a dressing motor, a diamond dressing roller and a mounting table, the bottom end of the mounting table is a round table, a fixing groove is formed in the bottom of the round table along the circumferential direction, a heightening block is arranged on the top surface of the round table, a pair of supports are arranged on the top surface of the heightening block, the dressing motor is fixed on the supports, and the diamond dressing roller is mounted on an output shaft of the dressing motor;

5. The high-efficiency precision grinding machining method for the RV cycloid gear according to claim 4, characterized in that; the grinding wheel motor drives the ring surface forming grinding wheel to rotate to form dressing auxiliary motion.

6. The high-efficiency precision grinding method for the RV cycloid gear according to claim 4, characterized in that: the torus forming grinding wheel moves close to or away from the diamond dressing roller, so that the dressing amount is adjusted.