An axial automatic backlash-eliminating planetary reducer

Abstract

The present invention belongs to the technical field of planetary speed reducers, and particularly relates to a planetary speed reducer with automatic axial clearance elimination, which includes a housing. A planetary reduction mechanism is provided inside the housing. The planetary reduction mechanism includes an internal gear ring, a planetary carrier, planetary gears, and a sun gear. Each planetary gear is arranged inside the internal gear ring and evenly distributed around the sun gear. The planetary gears are interconnected through the planetary carrier to form a planetary gear assembly. The outer periphery of the planetary gear assembly has a taper, and the internal gear ring is a tapered internal gear ring adapted to the planetary gear assembly. The internal gear ring can generate an axial displacement inside the housing. The planetary reduction mechanism is divided into two stages, and the taper directions of the first-stage internal gear ring and the second-stage internal gear ring are opposite. A two-way force balance mechanism is provided between the first-stage internal gear ring and the second-stage internal gear ring, so that the first-stage internal gear ring and the second-stage internal gear ring generate axial displacements in the same direction inside the housing. The transmission accuracy of this planetary speed reducer is greatly improved, and the service life is greatly extended, subverting and solving the common problems of existing planetary speed reducers.

Description

Technical Field

[0001] The present invention relates to a planetary reducer with automatic axial clearance elimination, belonging to the technical field of planetary reducers. Background Art

[0002] The planetary reducer is a widely used industrial product that can reduce the speed of the motor and increase the output torque at the same time. In the existing planetary reducer structure on the market, the internal gear ring is a rigid gear ring, which is connected to the rear end cover as a whole by bolts. As the service time prolongs, the internal gear ring will gradually wear, and the transmission clearance will become larger and larger, resulting in an increasing reverse clearance of the reducer, reducing the transmission accuracy, increasing the noise during operation, and even being unable to work properly in severe cases. Summary of the Invention

[0003] According to the above deficiencies in the prior art, the technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a planetary reducer with an adaptive internal gear ring that can automatically eliminate clearance axially to solve the above problems.

[0004] The planetary gear train with automatic radial clearance elimination of the present invention includes a housing. A planetary reduction mechanism is provided inside the housing. The planetary reduction mechanism includes an internal gear ring, a planet carrier, planetary gears, and a sun gear. Each planetary gear is arranged inside the internal gear ring and evenly distributed around the sun gear. The planetary gears are interconnected through the planet carrier to form a planetary gear assembly. The outer periphery of the planetary gear assembly has a taper, and the internal gear ring is a taper internal gear ring adapted to the planetary gear assembly. The internal gear ring can axially displace inside the housing.

[0005] The radial force generated by the axial movement of the taper internal gear ring will act on the planetary gear and then on the sun gear, thereby eliminating the transmission clearance between the gears.

[0006] The planetary reduction mechanism is divided into two stages. The taper directions of the first-stage internal gear ring and the second-stage internal gear ring are opposite. A two-way force balance mechanism is provided between the first-stage internal gear ring and the second-stage internal gear ring to make the first-stage internal gear ring and the second-stage internal gear ring axially displace in the same direction inside the housing.

[0007] The first-stage and second-stage planetary reduction mechanisms of the present invention are provided with axially adaptive internal gear rings, which are taper internal gear rings. A two-way force balance mechanism is installed at the connection part between the first-stage and second-stage taper internal gear rings. When any one of the taper internal gear rings axially displaces, it forces the other taper internal gear ring to axially displace in the same direction. Since the axial position of the planetary gear cannot axially shift, the radial force generated by the axial movement of the internal gear ring will act on the planetary gear and then on the sun gear, thereby eliminating the transmission clearance between the gears and greatly improving the transmission accuracy of the reducer.

[0008] The two-way force balance mechanism described in the present invention includes at least a pair of toothed cams. The gear parts of the two toothed cams are meshed together, and the tops of the two toothed cams respectively abut against the first-level internal gear ring and the second-level internal gear ring. As Figure 4 shown, when an external force is applied at point C, through the toothed cam structure, a force in the same direction will be generated at point B. When the force direction at point B is limited, it will pass through the toothed cam structure and transmit the acting force back to point C in the reverse direction, thus ensuring that the pressures at points B and C are consistent. Due to the relationship of the eccentric cam, the radial forces exerted by the first- and second-level tapered internal gear rings on the first- and second-level planet gears are always kept consistent, thereby eliminating the gear transmission clearance of the first- and second-level planetary reduction devices, and the amplitude of clearance elimination is also the same.

[0009] The toothed cam is rotatably arranged on a pin shaft, and the pin shaft is fixed on the outer ring of the needle bearing (as Figure 2 , 4 shown).

[0010] A number of pairs of toothed cams are provided, and the number of pairs of toothed cams are evenly distributed on the outer ring of the needle bearing (as Figure 3 shown).

[0011] The needle bearing is sleeved on a support ring, and the support ring positions the needle bearing radially and axially; a middle bearing is further included, and the middle bearing is sleeved on the first-level planet carrier, and the middle bearing supports and positions the support ring.

[0012] An output bearing is provided at the front end of the second-level planetary reduction mechanism, and a positioning bearing and an input bearing are provided at the rear end; the output bearing is sleeved on the second-level planet carrier, the input bearing is arranged outside the first-level sun gear, the positioning bearing is arranged outside the input bearing, and the output bearing, the positioning bearing and the input bearing position the second-level planetary reduction mechanism radially and axially.

[0013] The beneficial effects of the present invention compared with the prior art are:

[0014] The planetary speed reducer capable of automatically eliminating clearance axially described in the present invention has a reasonable and ingenious structural design. The internal gear ring can move axially. Due to the relationship of the eccentric cam, the radial forces exerted by the first- and second-level tapered internal gear rings on the first- and second-level planet gears are always kept consistent, thereby eliminating the gear transmission clearance of the first- and second-level planetary reduction devices, and the amplitude of clearance elimination is also the same. This greatly improves the transmission accuracy of the planetary speed reducer and greatly extends its service life, subversively solving the common problems of existing planetary speed reducers, and has broad development prospects and good economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a half-sectional structural schematic diagram of the present invention;

[0016] Figure 2 is Figure 1Partial enlarged view of part A in the figure;

[0017] Figure 3 Schematic diagram of the positional relationship between the two-way force balance mechanism and the needle roller bearing;

[0018] Figure 4 Schematic diagram of the principle of the two-way force balance mechanism.

[0019] In the figure: 1. Output shaft; 2. Secondary planet carrier; 3. Skeleton oil seal; 4. Output bearing; 5. Secondary planet gear; 6. Front housing; 7. Secondary internal gear ring; 8. Support ring; 9. Intermediate bearing; 10. Primary planet carrier; 11. Primary internal gear ring; 12. Primary planet gear; 13. Positioning bearing; 14. Input bearing; 15. Input shaft sleeve; 16. Primary sun gear; 17. Secondary sun gear; 18. Toothed cam; 19. Pin shaft; 20. Needle roller bearing. Specific implementation mode

[0020] The present invention will be further described below in conjunction with embodiments:

[0021] As Figures 1 to 4 shown, an axially self-eliminating clearance planetary speed reducer includes a housing, the housing is composed of a front housing 6 and a rear housing, and a skeleton oil seal 3 is provided at the front end of the housing. A two-stage planetary reduction mechanism is provided inside the housing. The primary planetary reduction mechanism includes a primary internal gear ring 11, a primary planet carrier 10, primary planet gears 12 and a primary sun gear 16. The secondary planetary reduction mechanism includes a secondary internal gear ring 7, a secondary planet carrier 2, secondary planet gears 5 and a secondary sun gear 17. The primary sun gear 16 is connected to the input shaft, the input shaft is connected to the input shaft sleeve 15 (the input shaft sleeve 15 is connected to the motor output shaft), the secondary planet carrier 2 is connected to the output shaft 1, and the primary planet carrier 10 is connected to the secondary sun gear 17. Each planet gear is arranged inside the internal gear ring and evenly distributed around the sun gear. The planet gears are interconnected through the planet carrier to form a planet gear assembly. The outer circumferences of the primary and secondary planet gear assemblies have a taper, and the internal gear ring is a taper internal gear ring adapted to the planet gear assembly. The taper directions of the primary internal gear ring 11 and the secondary internal gear ring 7 are opposite, and a two-way force balance mechanism is provided between the primary internal gear ring 11 and the secondary internal gear ring 7 to cause the primary internal gear ring 11 and the secondary internal gear ring 7 to generate axial displacements in the same direction inside the housing.

[0022] Among them, the two-way force balance mechanism includes toothed cams 18. The gear parts of the two toothed cams 18 are meshed together, and the tops of the two toothed cams 18 respectively abut against the primary internal gear ring 11 and the secondary internal gear ring 7. The toothed cam 18 is rotatably arranged on the pin shaft 19, and the pin shaft 19 is fixed on the outer ring of the needle roller bearing 20. A number of pairs of toothed cams 18 are provided, and a number of pairs of toothed cams 18 are evenly distributed on the outer ring of the needle roller bearing 20.

[0023] The needle bearing 20 of this embodiment is sleeved on the support ring 8, and the support ring 8 radially and axially positions the needle bearing 20; it also includes an intermediate bearing 9, which is sleeved on the primary planetary carrier 10, and the intermediate bearing 9 supports and positions the support ring 8. The front end of the two-stage planetary reduction mechanism is provided with an output bearing 4, and the rear end is provided with a positioning bearing 13 and an input bearing 14; the output bearing 4 is sleeved on the secondary planetary carrier 2, the input bearing 14 is arranged outside the primary sun gear 16, and the positioning bearing 13 is arranged outside the input bearing 14. The output bearing 4, the positioning bearing 13 and the input bearing 14 radially and axially position the two-stage planetary reduction mechanism. The housing cooperates with the output bearing 4, the intermediate bearing 9, the positioning bearing 13 and the input bearing 14 to position the components in the housing 5, which cleverly solves the problem of positioning the internal components.

[0024] The first and second planetary reduction mechanism of the present invention is provided with an axially adaptive inner gear ring, which is a tapered inner gear ring. A bidirectional force balancing mechanism, ie, an eccentric cam, is installed at the middle connection part of the first and second tapered inner gear rings. When an external force is applied to point C, point B will be subjected to force in the same direction through the toothed cam structure. When the force direction of point B is limited, the force will be reversed and transmitted back to point C through the toothed cam structure, thus ensuring that the pressure at points B and C is consistent. When any of the tapered inner gear rings produces an axial displacement, the eccentric cam is forced to rotate, thereby triggering the other tapered inner gear ring to produce a displacement in the same direction. Since the axial position of the planetary gear cannot be axially offset, the radial force generated by the axial movement of the inner gear ring will act on the planetary gear, and then act on the sun gear, thereby eliminating the transmission gap between the gears, and greatly improving the transmission accuracy of the reducer. Due to the eccentric cam, the radial force of the first and second tapered inner gear rings acting on the first and second planetary gears is always consistent, thereby eliminating the gear transmission gap of the first and second planetary reduction device, and the clearance elimination amplitude is also consistent. The transmission accuracy of this planetary reducer is greatly improved, the service life is greatly extended, and the common problems of existing planetary reducers are subversively solved, with significant economic and social benefits.

Claims

1. An axial automatic backlash-eliminating planetary reducer, comprising a housing, a planetary reduction mechanism is arranged inside the housing, the planetary reduction mechanism includes an internal gear ring, a planetary carrier, planetary gears and a sun gear, each planetary gear is arranged inside the internal gear ring and evenly distributed around the sun gear, the planetary gears are interconnected through the planetary carrier to form a planetary gear assembly, and it is characterized in that: The outer periphery of the planetary gear assembly has a taper, and the internal gear ring is a tapered internal gear ring adapted to the planetary gear assembly. The internal gear ring can generate an axial displacement within the housing. The planetary reduction mechanism is divided into two stages. The taper directions of the first-stage internal gear ring (11) and the second-stage internal gear ring (7) are opposite. A two-way force balance mechanism is provided between the first-stage internal gear ring (11) and the second-stage internal gear ring (7) to cause the first-stage internal gear ring (11) and the second-stage internal gear ring (7) to generate axial displacements in the same direction within the housing. The two-way force balance mechanism includes at least a pair of toothed cams (18). The gear parts of the two toothed cams (18) are meshed together, and the tops of the two toothed cams (18) respectively abut against the first-stage internal gear ring (11) and the second-stage internal gear ring (7). An output bearing (4) is provided at the front end of the second-stage planetary reduction mechanism, and a positioning bearing (13) and an input bearing (14) are provided at the rear end. The output bearing (4) is sleeved on the second-stage planetary carrier (2). The input bearing (14) is arranged outside the first-stage sun gear (16), the positioning bearing (13) is arranged outside the input bearing (14), and the output bearing (4), the positioning bearing (13) and the input bearing (14) perform radial and axial positioning on the second-stage planetary reduction mechanism.

2. The planetary speed reducer with axially automatically clearance eliminating according to claim 1, wherein: The toothed cam (18) is rotatably arranged on a pin shaft (19), and the pin shaft (19) is fixed on the outer ring of a needle bearing (20).

3. The planetary speed reducer with automatic axial clearance elimination according to claim 2, characterized in that: A plurality of pairs of toothed cams (18) are provided, and the plurality of pairs of toothed cams (18) are evenly distributed on the outer ring of the needle bearing (20).

4. The planetary speed reducer with automatic axial clearance elimination according to claim 2 or 3, characterized in that: The needle bearing (20) is sleeved on a support ring (8), and the support ring (8) performs radial and axial positioning on the needle bearing (20). It also includes an intermediate bearing (9). The intermediate bearing (9) is sleeved on the first-stage planetary carrier (10), and the intermediate bearing (9) performs support and positioning on the support ring (8).

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