Compound planetary reducer

Abstract

The invention relates to the technical field of speed reducers, in particular to a compound planetary speed reducer which comprises a shell assembly, a main planetary transmission assembly, an auxiliary planetary transmission assembly and an output shaft. The input end of the main planetary transmission assembly is used for being in concentric transmission connection with an output shaft of a servo motor, the output end of the main planetary transmission assembly is in transmission connection with the input end of the auxiliary planetary transmission assembly, and an output gear is arranged at the extending end of an auxiliary center rotating shaft of the auxiliary planetary transmission assembly. Wherein the main planetary transmission assembly and the auxiliary planetary transmission assembly form a secondary planetary gear transmission assembly; the output shaft is rotationally connected to one side of the shell assembly, one end of the output shaft extends into the shell assembly and then is connected with a transmission gear, the transmission gear and the output gear are in meshing transmission, and the output shaft and the input end of the main planetary transmission assembly are coaxial. The compound planetary reducer is small in axial size, and the structure of the compound planetary reducer in the axial direction of the output shaft is more compact.

Description

Technical Field

[0001] The present invention relates to the technical field of speed reducers, and particularly to a compound planetary speed reducer. Background Art

[0002] Planetary speed reducers are widely used in the design of various transmission structures due to their many advantages such as small structural size, light weight, large transmitted power, wide speed ratio range, and low noise.

[0003] Since the speed ratio of existing planetary speed reducers is formed by connecting a single basic reduction unit in series, except for the first-stage reducer, for second-stage and third-stage planetary speed reducers, their axial length dimensions are relatively long; in some applications with small size requirements, this long axial length will cause certain difficulties in the layout of the transmission structure.

[0004] Therefore, it is necessary to provide a compound planetary speed reducer to solve the above problems. Summary of the Invention

[0005] The present invention provides a compound planetary speed reducer. Based on the basic reduction unit, an output gear is only provided at the output end of the reduction unit, so that the output gear meshes with the transmission gear of the output shaft, thereby reducing the axial dimension, and solving the problem that the speed ratio of the existing planetary speed reducer is formed by connecting basic reduction units in series, resulting in a long axial gear length and being difficult to use in applications with small sizes.

[0006] A compound planetary speed reducer of the present invention adopts the following technical solutions, including: A housing assembly; A main planetary transmission assembly and a secondary planetary transmission assembly, which are arranged in the housing assembly. The input end of the main planetary transmission assembly is used for concentric transmission connection with the output shaft of the servo motor. The output end of the main planetary transmission assembly is in transmission connection with the input end of the secondary planetary transmission assembly. An output gear is provided on the extended end of the secondary central rotating shaft of the secondary planetary transmission assembly; wherein, the main planetary transmission assembly and the secondary planetary transmission assembly form a two-stage planetary gear transmission assembly; And an output shaft, which is rotatably connected to one side of the housing assembly, and one end of which extends into the housing assembly and is connected with a transmission gear. The transmission gear and the output gear are in meshing transmission, wherein the output shaft is coaxial with the input end of the main planetary transmission assembly.

[0007] Preferably, the main planetary transmission assembly includes: A main planetary carrier, on which a main central shaft is passed through. One end of the main central shaft is rotatably connected to the inner wall of the housing assembly, and the other end of the main central shaft is rotatably connected to the end of the output shaft; the end of the main central shaft extending out of the housing assembly is used for concentric transmission connection with the output shaft sleeved on the servo motor.

[0008] A main central gear, which is sleeved and fixed on the main central shaft; and a plurality of main planetary gears, evenly distributed between the main sun gear and the inner wall of the housing assembly; Among them, the main planetary gears are ring gears with teeth on both the inner and outer rings. The outer ring of each main planetary gear is meshed with the main central gear and the inner gear ring arranged on the inner wall of the housing assembly. The inner ring of the main planetary gear is transmission connected to the input end of the auxiliary planetary transmission assembly.

[0009] Preferably, the secondary planetary transmission assembly comprises: A secondary planet carrier, on which a secondary sun gear shaft is passed, one end of which is rotatably connected to the main planet carrier, and the other end of which passes through the main planet carrier and is connected to an output gear, wherein each output gear is meshed with a transmission gear, and the secondary sun gear shaft is coaxial with the main planet gear; A secondary center gear, which is fixed on the secondary center gear shaft; And a plurality of auxiliary planetary gears are evenly distributed between the auxiliary sun gear and the inner ring of the main planetary gear, and each auxiliary planetary gear is meshed with the auxiliary sun gear and the inner ring of the main planetary gear.

[0010] Preferably, the shell assembly includes: a cylindrical shell, a front cover plate and a rear cover plate, wherein a center mounting hole is arranged in the center of the front cover plate and the rear cover plate, one end of the main center shaft is connected to the center mounting hole of the front cover plate through a first bearing, and the other end of the main center shaft is rotatably connected to the mounting groove arranged on the end face of the output shaft through a second bearing.

[0011] Preferably, a bearing mounting cylinder is concentrically connected to the central mounting hole of the rear cover plate, the output shaft is mounted in the bearing mounting cylinder through two third bearings, and an end cover is provided at one end of the bearing mounting cylinder away from the rear cover plate, wherein the end of the output shaft passes through the end cover.

[0012] Preferably, the end cover and the output shaft are sealed by an oil seal.

[0013] Preferably, the two third bearings are arranged at intervals along the axial direction of the output shaft, and a bearing spacer is provided between the inner rings and between the outer rings of the two third bearings.

[0014] Preferably, the front cover plate and the cylindrical shell, the rear cover plate and the cylindrical shell, and the end cover and the bearing sleeve are all connected by screws.

[0015] The beneficial effects of the present invention are: A two-stage planetary transmission assembly formed by a main planetary transmission assembly and a secondary planetary transmission assembly, and the output end of the secondary planetary transmission assembly is in transmission connection with the output shaft. That is, an output gear is provided at the extended end of the secondary central gear shaft of the secondary planetary transmission assembly, and the output gear meshes with the transmission gear on the output shaft for transmission. This enables the entire deceleration process to achieve primary deceleration from the servo motor to the main planetary transmission assembly, secondary deceleration in the transmission process from the main planetary transmission assembly to the secondary planetary transmission assembly, and tertiary deceleration in the transmission process from the secondary planetary transmission assembly to the output shaft. That is, the total transmission ratio of the compound planetary gear reducer of the present invention is the product of the transmission ratios of primary deceleration, secondary deceleration, and tertiary deceleration. In this way, tertiary deceleration is achieved. At the same time, only the output gear is added axially, and the output gear is provided at the extended end of the secondary central gear shaft of the secondary planetary transmission assembly, and its axial direction remains unchanged. That is, it can be ensured that the axial dimension of the tertiary reducer of the present invention is much smaller than that of the traditional planetary gear reducer, and the structure in the axial direction of the output shaft is more compact. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0017] Figure 1 It is a cross-sectional view of the overall structure of a compound planetary reducer of the present invention; Figure 2 It is a transmission schematic diagram of the main planetary transmission assembly and the secondary planetary transmission assembly in a compound planetary reducer of the present invention; Figure 3 It is a structural schematic diagram of the main planetary carrier of the main planetary transmission assembly; Figure 4 It is a structural schematic diagram of the main planetary carrier of the secondary planetary transmission assembly; Figure 5 It is a transmission schematic diagram of the output gear on the secondary central gear shaft of the secondary planetary transmission assembly and the transmission gear on the output shaft.

[0018] In the figure: 1, cylindrical housing; 2, internal gear ring; 3, main planetary gear; 4, secondary planetary gear; 5, secondary central gear; 6, main central gear; 7, servo motor; 8, first bearing; 9, main planetary carrier; 10, front cover plate; 11, second bearing; 12, bearing spacer; 13, oil seal; 14, output shaft; 15, end cover; 16, third bearing; 17, transmission gear; 18, output gear; 19, rear cover plate; 20, secondary planetary carrier. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] An embodiment of a compound planetary reducer of the present invention is as follows Figure 1 As shown, it includes: a housing assembly, a main planetary transmission assembly, a secondary planetary transmission assembly and an output shaft 14, wherein the housing assembly includes: a cylindrical housing 1, a front cover plate 10 and a rear cover plate 19, wherein the centers of the rear cover plate 19 and the front cover plate 10 are both provided with a central mounting hole, and the main planetary transmission assembly and the secondary planetary transmission assembly are both arranged in the housing assembly, as shown in FIG. Figure 1 As shown, the input end of the main planetary transmission assembly is used for coaxial transmission connection with the output shaft of the servo motor 7, the output end of the main planetary transmission assembly is transmission-connected with the input end of the auxiliary planetary transmission assembly, and an output gear 18 is provided on the extended end of the auxiliary center shaft of the auxiliary planetary transmission assembly; wherein the main planetary transmission assembly and the auxiliary planetary transmission assembly constitute a secondary planetary gear transmission assembly; the output shaft 14 is rotationally connected to one side of the housing assembly, that is, a bearing mounting cylinder is coaxially connected to the central mounting hole of the rear cover plate 19, the output shaft 14 is installed in the bearing mounting cylinder through two third bearings 16, and an end cover 15 is provided at one end of the bearing mounting cylinder away from the rear cover plate 19, wherein the end of the output shaft 14 passes through the end cover 15, as shown in FIG. Figure 5 As shown, one end of the output shaft 14 extends into the housing assembly and is connected to a transmission gear 17, and the transmission gear 17 and the output gear 18 are meshed for transmission, wherein the output shaft 14 is coaxial with the input end of the main planetary transmission assembly.

[0021] like Figure 1 As shown, the main planetary transmission assembly includes: a main sun gear 6, two main planet carriers 9 and three main planetary gears 3, as shown in FIG. Figure 3 As shown, the main planet carrier 9 is a triangular planet carrier, and the main center shaft is passed through the central mounting hole of the triangular planet carrier. One end of the main center shaft is rotatably connected through the first bearing 8 and the mounting hole provided on the front cover plate 10 of the housing assembly, and the other end of the main center shaft is rotatably connected through the second bearing 11 and the groove provided on the end surface of the output shaft 14; the end of the main center shaft extending out of the front cover plate 10 of the housing assembly is used for coaxial transmission connection with the output shaft sleeved on the servo motor 7. It should be noted that, as shown in FIG. Figure 1As shown in the figure, the end face of one main planet carrier 9 is limited by the shoulder provided on the main central axis, and the end face of the other main planet carrier 9 is in contact and limited with the end face of the second bearing 11; the main central gear 6 is sleeved and fixed on the main central axis; three main planet gears 3 are arranged between the main central gear 6 and the inner wall of the housing assembly. Among them, as Figure 2 shown, the main planet gear 3 is an annular gear with teeth on both the inner and outer rings. The outer ring of each main planet gear 3 meshes with the main central gear 6 and the internal gear ring 2 provided on the inner wall of the housing assembly, and the inner ring of the main planet gear 3 is in transmission connection with the input end of the secondary planetary transmission assembly.

[0022] As Figure 1 and Figure 2 shown, the secondary planetary transmission assembly includes: a secondary central gear 5, two secondary planet carriers 20, and three secondary planet gears 4. As Figure 4 shown, the secondary planet carrier 20 is also a triangular planet carrier. A secondary central gear shaft is passed through the central mounting hole of the triangular planet carrier. One end of the secondary central gear shaft is rotatably connected to the main planet carrier 9, and the other end of the secondary central gear shaft passes through the main planet carrier 9 and is connected with an output gear 18. Among them, the secondary central gear shaft is coaxial with the main planet gear 3; it should be noted that the two secondary planet carriers 20 are located on the secondary central gear shaft between the two main planet carriers 9, and the secondary central gear 5 is sleeved and fixed on the secondary central gear shaft between the two secondary planet carriers 20; the three secondary planet gears 4 are evenly arranged between the secondary central gear 5 and the inner ring of the main planet gear 3, and each secondary planet gear 4 meshes with the secondary central gear 5 and the inner ring of the main planet gear 3.

[0023] In order to prevent lubricating oil leakage, the end cover 15 and the output shaft 14 are sealed by an oil seal 13.

[0024] In order to ensure that the output shaft 14 rotates more smoothly, two third bearings 16 are arranged at intervals along the axial direction of the output shaft 14, and bearing spacers 12 are arranged between the inner rings and between the outer rings of the two third bearings 16.

[0025] In this embodiment, the front cover plate 10 and the cylindrical housing 1, the rear cover plate 19 and the cylindrical housing 1, and the end cover 15 and the bearing sleeve are all connected by screws.

[0026] Working principle In use, the main central shaft of the compound planetary speed reducer of the present invention is connected to the output end of the servo motor 7 through a coupling. The servo motor 7 is started, and the servo motor 7 transmits the rotational torque to the main central shaft of the main planetary transmission assembly. The main central shaft drives the main central gear 6 to rotate. Under the limitation of the internal gear ring 2, the main central gear 6 drives the main planetary gear 3 to rotate self while revolving within the internal gear ring 2, that is, the first-stage planetary transmission is realized. Then, during the revolution of the main planetary gear 3, the inner ring of the main planetary gear 3 and the secondary planetary gear 4 of the secondary planetary transmission assembly achieve transmission, so that the secondary planetary gear 4 of the secondary planetary transmission assembly revolves and rotates on the inner ring of the main planetary gear 3. Since the secondary planetary gear 4 meshes with the secondary central gear 5, the secondary planetary gear 4 drives the secondary central gear 5 to rotate, realizing the second-stage planetary transmission. At the same time, the secondary central gear 5 transmits the torque to the secondary central gear shaft, and the secondary central gear shaft drives the output gear 18 to rotate. The output gear 18 meshes with the transmission gear 17 to drive the transmission gear 17 to rotate, thereby transmitting the torque to the output shaft 14. The entire deceleration process realizes the first-stage deceleration from the servo motor 7 to the main planetary transmission assembly, and the first-stage transmission ratio is i1. The transmission process from the main planetary transmission assembly to the secondary planetary transmission assembly realizes the second-stage deceleration, and the transmission ratio of the second-stage deceleration is i2. The transmission process from the secondary planetary transmission assembly to the output shaft realizes the third-stage deceleration, and the transmission ratio of the third-stage deceleration is i3. That is, the total transmission ratio i of the compound planetary gear speed reducer in this embodiment is i = i1 × i2 × i3. In this way, the three-stage deceleration speed reducer of the present invention can be much smaller in axial dimension than the traditional planetary gear speed reducer, and the structure is more compact in the axial direction of the output shaft.

[0027] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A compound planetary reducer, characterized in that, include: Shell assembly; The main planetary transmission assembly and the auxiliary planetary transmission assembly are arranged in the housing assembly, the input end of the main planetary transmission assembly is used for coaxial transmission connection with the output shaft of the servo motor, the output end of the main planetary transmission assembly is transmission connected with the input end of the auxiliary planetary transmission assembly, and the extension end of the auxiliary center shaft of the auxiliary planetary transmission assembly is provided with an output gear; wherein the main planetary transmission assembly and the auxiliary planetary transmission assembly constitute a two-stage planetary gear transmission assembly; And an output shaft, which is rotatably connected to one side of the housing assembly, and one end of which is extended into the housing assembly and connected to a transmission gear, the transmission gear and the output gear are meshed for transmission, wherein the output shaft and the input end of the main planetary transmission assembly are coaxial.

2. The compound planetary speed reducer according to claim 1, characterized in that, The main planetary drive assembly includes: The main planetary carrier is provided with a main center shaft, one end of which is rotatably connected to the inner wall of the housing assembly, and the other end of the main center shaft is rotatably connected to the end of the output shaft; one end of the main center shaft extending out of the housing assembly is used for coaxial transmission connection with the output shaft sleeved on the servo motor. A main center gear, which is set and fixed on the main center shaft; and a plurality of main planetary gears, evenly distributed between the main sun gear and the inner wall of the housing assembly; Among them, the main planetary gears are ring gears with teeth on both the inner and outer rings. The outer ring of each main planetary gear is meshed with the main central gear and the inner gear ring arranged on the inner wall of the housing assembly. The inner ring of the main planetary gear is transmission connected to the input end of the auxiliary planetary transmission assembly.

3. The compound planetary speed reducer according to claim 2, characterized in that, The auxiliary planetary transmission assembly includes: A secondary planet carrier, on which a secondary sun gear shaft is passed, one end of which is rotatably connected to the main planet carrier, and the other end of which passes through the main planet carrier and is connected to an output gear, wherein each output gear is meshed with a transmission gear, and the secondary sun gear shaft is coaxial with the main planet gear; A secondary center gear, which is fixed on the secondary center gear shaft; And a plurality of auxiliary planetary gears are evenly distributed between the auxiliary sun gear and the inner ring of the main planetary gear, and each auxiliary planetary gear is meshed with the auxiliary sun gear and the inner ring of the main planetary gear.

4. A compound planetary speed reducer according to claim 2, characterized in that, The housing assembly includes: a cylindrical housing, a front cover plate and a rear cover plate, wherein a center mounting hole is provided in the center of the front cover plate and the rear cover plate, one end of the main center shaft is connected to the center mounting hole of the front cover plate through a first bearing, and the other end of the main center shaft is rotatably connected to the mounting groove provided on the end face of the output shaft through a second bearing.

5. A compound planetary speed reducer according to claim 4, characterized in that, A bearing mounting cylinder is concentrically connected to the central mounting hole of the rear cover plate, and the output shaft is mounted in the bearing mounting cylinder through two third bearings. An end cap is arranged at one end of the bearing mounting cylinder away from the rear cover plate, wherein the end of the output shaft passes through the end cap.

6. The compound planetary speed reducer according to claim 5, characterized in that, The end cover and the output shaft are sealed by an oil seal.

7. A compound planetary speed reducer according to claim 5, characterized in that, The two third bearings are arranged at intervals along the axial direction of the output shaft, and a bearing spacer is arranged between the inner rings and the outer rings of the two third bearings.

8. A compound planetary speed reducer according to claim 6, characterized in that, The front cover plate and the cylindrical shell, the rear cover plate and the cylindrical shell, and the end cover and the bearing sleeve are all connected by screws.

Images