A two-stage planetary deceleration module suitable for frameless motor

Abstract

The utility model discloses a kind of two-stage planetary reduction module suitable for frameless motor, belong to robot movement field, to solve the problem of poor integration when existing frameless motor adapts reduction module, insufficient reduction capacity.The module includes motor, two-stage planetary reduction mechanism, motor shell, shell end cover and output flange;Motor contains coaxially arranged stator winding and motor rotor, and motor rotor is ladder shaft structure;Two-stage planetary reduction mechanism is composed of primary reduction unit and secondary reduction unit, primary sun gear is connected with motor rotor by first sun shaft, secondary sun gear is connected with primary planetary gear by first planet carrier, and output flange is connected with second planet shaft, and first gear ring is arranged on the inner wall of motor shell.The utility model does not need transition component, and integration is high, two-stage reduction can realize high transmission ratio, and transmission precision is high, support is stable, effectively improve equipment load capacity and operating reliability.

Description

Technical Field

[0001] This utility model relates to the field of robot motion, and in particular to a two-stage planetary reduction module adapted to a frameless motor. Background Technology

[0002] Frameless motors, by eliminating the redundant structures of traditional motors such as the casing and end caps, possess core advantages such as small size, high power density, and strong installation flexibility, making them the mainstream power source for small collaborative robots and precision automated equipment. However, frameless motors have relatively low output torque, requiring a reduction gear mechanism to achieve "speed reduction and torque increase." Existing adaptation solutions have the following significant drawbacks:

[0003] 1. Poor integration of motor and reduction mechanism: Traditional reduction modules are mostly designed to be compatible with frame motors. When combined with frameless motors, additional transition brackets and couplings are required, which makes the assembly process complicated. Moreover, the transition components are prone to introducing coaxiality errors (usually ≥0.1mm), which will generate radial runout and vibration during high-speed operation, affecting the transmission accuracy.

[0004] II. The Conflict Between Space Constraints and Reduction Capacity: Due to space limitations, existing reduction modules often only have a single-stage reduction, resulting in poor reduction capability. The transmission ratio of a single-stage planetary reducer is typically only 3-10 times, far from meeting the requirements of various scenarios. Taking the common input speed of 1500 r / min for frameless motors as an example, if a single-stage reduction is used, the output speed is still as high as 150 r / min, and the torque is only amplified by 10 times; while the joints of small collaborative robots require an output speed of ≤50 r / min and a torque amplification of more than 25 times, which a single-stage reduction simply cannot achieve, leading to a decrease in the equipment's load capacity, or even the inability to drive the actuator.

[0005] To address the aforementioned issues, there is an urgent need for a two-stage planetary gear reducer module that can be deeply integrated with frameless motors, provides stable support for rotating components, and has reasonable stress distribution. Utility Model Content

[0006] The present invention aims to provide a two-stage planetary reduction module adapted to frameless motors, which solves the problems of poor integration between motor and reduction mechanism and insufficient reduction capacity in the prior art, realizes deep integration with frameless motors, improves transmission accuracy, enhances reduction and torque increase effect, and at the same time ensures stable support and reasonable force distribution of rotating parts.

[0007] A two-stage planetary gear reducer module adapted to a frameless motor includes a motor, a two-stage planetary gear reducer mechanism, a motor housing, a housing end cover, and an output flange. The motor includes a stator winding and a motor rotor arranged coaxially. A rotor yoke is provided on the outer ring of the motor rotor. The main body of the motor rotor has a stepped shaft structure, with a first outer ring and a first inner ring on its axial sides, respectively. The first outer ring is rotatably connected to the housing end cover through a first bearing, and the first inner ring is rotatably connected to a first planetary carrier through a second bearing. The two-stage planetary gear reducer mechanism includes a first-stage reduction unit and a second-stage reduction unit. The first-stage reduction unit includes a first-stage sun gear, multiple first-stage planetary teeth located outside the first-stage sun gear, and a first gear ring meshing with the first-stage planetary teeth. The second-stage reduction unit includes a second-stage sun gear, multiple second-stage planetary teeth located outside the second-stage sun gear, and a second gear ring meshing with the second-stage planetary teeth. The first-stage sun gear is sleeved on a first sun shaft, which is connected to the motor rotor. The second-stage sun gear is connected to the first-stage planetary gear through a first planetary carrier. The output flange is connected to a second planetary shaft. The first gear ring is located on the inner surface of the motor housing, and the second gear ring is an independent unit.

[0008] Furthermore, the first planetary carrier includes a transmission support, a stabilizing support, and four first planetary shafts, the first planetary shafts being located between the transmission support and the stabilizing support, and the transmission support being connected to the second sun axis.

[0009] The four evenly distributed first planetary shafts can evenly distribute the load of the first-stage planetary gears, avoiding deformation or breakage of a single planetary shaft due to concentrated force, and significantly improving the load-bearing capacity of the first planetary carrier. On the other hand, the transmission support and the stabilizing support form a "double support" structure, which enhances the overall rigidity of the first planetary carrier, effectively suppresses radial runout during high-speed operation, and reduces error loss in the power transmission process through reliable connection with the second sun shaft, ensuring the transmission continuity between the first-stage reduction unit and the second-stage reduction unit, and improving the overall transmission accuracy of the module.

[0010] Furthermore, the stator winding is fixed to the inner wall of the motor housing, and the axis of the stator winding coincides with the axis of the motor rotor. The lead-out end of the stator winding extends to the outside of the motor housing through a through hole opened radially along the motor housing.

[0011] Furthermore, the rotor yoke is a ring structure, and its inner wall is connected to the outer ring of the motor rotor by an interference fit. Multiple permanent magnets are uniformly embedded in the outer wall of the rotor yoke along the circumference.

[0012] Furthermore, the number of primary planetary teeth is 4-6, and the number of secondary planetary teeth is 3-5, with the number of secondary planetary teeth being less than the number of primary planetary teeth.

[0013] The primary planetary gears, with their numerous design, are adapted to high-speed, low-torque power characteristics, ensuring smooth transmission and load-bearing capacity. The secondary planetary gears, with their fewer design, are adapted to low-speed, high-torque power characteristics, balancing transmission efficiency and space adaptability. The combination of the two enables the secondary planetary reduction mechanism to achieve efficient "speed reduction and torque increase" and to be deeply integrated with frameless motors, meeting the needs of small collaborative robots and other equipment.

[0014] Furthermore, the left end of the second gear ring is provided with an annular boss, on which multiple threaded through holes are evenly distributed circumferentially. The second gear ring is connected to the motor housing by bolts passing through the threaded through holes, and the axis of the second gear ring coincides with the axis of the motor rotor. The annular boss provides a precise positioning reference for the second gear ring, and together with the evenly distributed bolts circumferentially, it ensures that the second gear ring is evenly stressed during fixing, avoiding deformation of the gear ring due to uneven fixing, and thus preventing meshing deviation between the secondary planetary gear and the second gear ring.

[0015] Furthermore, both the first and second sun shafts are equipped with keyways, and corresponding keyways are provided on the motor rotor and the first planetary carrier. The first sun shaft and the motor rotor are circumferentially fixed by a flat key. The keyway structure is the core design for achieving "circumferential fixation," which can effectively prevent relative sliding between the first sun shaft and the motor rotor, and between the second sun shaft and the first planetary carrier, avoiding "slippage" during power transmission and reducing power loss.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0017] I. High integration and excellent transmission accuracy: This utility model directly integrates a frameless motor, eliminating the need for additional transition brackets and couplings, thus simplifying the assembly process; at the same time, it avoids coaxiality errors introduced by transition components, significantly reducing coaxiality errors, greatly reducing radial runout and vibration during high-speed operation, and effectively improving transmission accuracy.

[0018] II. Significant speed reduction and torque amplification effect: The two-stage planetary reduction mechanism allows for flexible design of the transmission ratio, easily achieving a torque amplification of more than 25 times. This reduces the output speed of the frameless motor to below 50 r / min, meeting the usage requirements of small collaborative robot joints and other scenarios, and improving the load capacity and drive reliability of the equipment.

[0019] 3. Stable support and reasonable stress distribution: The motor rotor is connected to the outer casing end cover and the first planetary carrier through double bearings respectively. The output flange is supported in multiple directions. With the optimized structure of the first planetary carrier, the rotating parts of the entire module are stably supported and the stress is evenly distributed, which effectively extends the service life of the module. Attached Figure Description

[0020] Figure 1This is a schematic diagram of the overall structure of a two-stage planetary gear reducer module adapted to frameless motors;

[0021] Figure 2 It was a localized explosion in the transmission component inside the speed reduction module. Figure 1 ;

[0022] Figure 3 It was a localized explosion in the transmission component inside the speed reduction module. Figure 2 ;

[0023] Figure 4 This is a schematic diagram of the first planetary carrier structure. Figure 1 ;

[0024] Figure 5 This is a schematic diagram of the first planetary carrier structure. Figure 2 ;

[0025] In the diagram: 1. Output flange, 2. Second gear ring, 3. Second planetary shaft, 4. Second sun shaft, 5. Motor housing, 6. First planetary carrier, 61. Transmission bracket, 62. First planetary shaft, 63. Stabilizing bracket, 7. First sun shaft, 8. Motor rotor. Detailed Implementation

[0026] To enhance understanding of this utility model, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. These embodiments are only used to explain the present utility model and do not constitute a limitation on the scope of protection of the present utility model.

[0027] Example 1: As Figure 1-5 As shown, the two-stage planetary reduction module adapted to frameless motors includes a motor, a two-stage planetary reduction mechanism, a motor housing 5, a housing end cover, and an output flange 1. The motor includes a stator winding and a motor rotor 8 arranged coaxially. The stator winding is fixed to the inner wall of the motor housing 5 and its axis coincides with the motor rotor 8. Its output end extends to the outside of the motor housing 5 through a through hole opened radially along the motor housing 5.

[0028] The motor rotor 8 has a stepped shaft structure, with a first outer ring and a first inner ring on both sides of the axial direction. The first outer ring is rotatably connected to the housing end cover through a first bearing, and the first inner ring is rotatably connected to the first planetary carrier 6 through a second bearing. The outer ring of the motor rotor 8 is also provided with an annular rotor yoke. The inner wall of the rotor yoke is connected to the outer ring of the motor rotor 8 by an interference fit, and multiple permanent magnets are uniformly embedded in the outer wall along the circumference.

[0029] The two-stage planetary reduction mechanism includes a primary reduction unit and a secondary reduction unit. The primary reduction unit includes a primary sun gear (not shown in the figure), multiple primary planetary gears (not shown in the figure) located outside the primary sun gear (not shown in the figure), and a first gear ring (gear portion not shown in the figure) meshing with the primary planetary gears. The primary planetary gears (not shown in the figure) are mounted on the first planetary shaft 62, and the secondary planetary gears (not shown in the figure) are mounted on the second planetary shaft 3.

[0030] The secondary reduction unit includes a secondary sun gear (not shown in the figure), three secondary planetary gears (not shown in the figure) located outside the secondary sun gear (not shown in the figure), and a second gear ring 2 (gear part not shown in the figure) meshing with the secondary planetary gears; the first gear ring is located on the inner surface of the motor housing.

[0031] The first-stage sun gear is mounted on the first sun shaft 7, which is connected to the motor rotor 8. The second-stage sun gear is connected to the four first-stage planetary gears via the first planetary carrier 6. The output flange 1 revolves together with the second planetary shaft 3.

[0032] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A two-stage planetary reduction module adapted for frameless electric motors, characterized in that, Includes a motor, a two-stage planetary reduction gear, a motor housing (5), housing end caps, and an output flange (1); The motor includes a stator winding and a motor rotor (8) arranged coaxially. The outer ring of the motor rotor (8) is provided with a rotor yoke. The main body of the motor rotor (8) is a stepped shaft structure, with a first outer ring and a first inner ring respectively on both sides of its axial direction. The first outer ring is rotatably connected to the outer casing end cover through a first bearing, and the first inner ring is rotatably connected to the first planetary carrier (6) through a second bearing. The secondary planetary deceleration mechanism includes a primary deceleration unit and a secondary deceleration unit; The first-stage reduction unit includes a first-stage sun tooth, a plurality of first-stage planetary teeth located outside the first-stage sun tooth, and a first gear ring that meshes with the first-stage planetary teeth. The secondary reduction unit includes a secondary sun tooth, a plurality of secondary planetary teeth located outside the secondary sun tooth, and a second gear ring (2) that meshes with the secondary planetary teeth. The first-stage sun gear is mounted on the first sun shaft (7), which is connected to the motor rotor (8). The second-stage sun gear is connected to the first-stage planetary gear via the first planetary carrier (6). The output flange (1) is connected to the second planetary shaft, the first gear ring is located on the inner surface of the motor housing (5), and the second gear ring is an independent unit.

2. The two-stage planetary reduction module of claim 1, wherein, The first planetary carrier (6) includes a transmission support (61), a stabilizing support (63) and four first planetary shafts (62), the first planetary shafts (62) being located between the transmission support (61) and the stabilizing support (63), and the transmission support (61) being connected to the second sun axis (4).

3. The secondary planetary reduction module of claim 1, wherein, The stator winding is fixed to the inner wall of the motor housing (5), and the axis of the stator winding coincides with the axis of the motor rotor (8). The lead-out end of the stator winding extends to the outside of the motor housing (5) through the through hole opened in the radial direction of the motor housing (5).

4. The secondary planetary reduction module of claim 3, wherein, The rotor yoke is a ring structure, and its inner wall is connected to the outer ring of the motor rotor (8) by interference fit. Multiple permanent magnets are uniformly embedded in the outer wall of the rotor yoke along the circumference.

5. The secondary planetary reduction module of claim 1, wherein, The number of primary planetary teeth is 4-6, and the number of secondary planetary teeth is 3-5, with the number of secondary planetary teeth being less than the number of primary planetary teeth.

6. The two-stage planetary reduction module of claim 5, wherein, The left end of the second gear ring (2) is provided with an annular boss. Multiple threaded through holes are evenly opened along the circumference of the annular boss. The second gear ring (2) is connected to the motor housing by bolts passing through the threaded through holes, and the axis of the second gear ring (2) coincides with the axis of the motor rotor (8).

7. The secondary planetary reduction module of claim 1, wherein, Both the first sun shaft (7) and the second sun shaft (4) are provided with keyways, and the motor rotor (8) and the first planetary carrier are provided with matching keyways.

8. The two-stage planetary reduction module of claim 7, wherein, The first sun shaft (7) and the motor rotor (8) are circumferentially fixed by a flat key.

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