Gear motor

Abstract

The invention relates to the technical field of motors, in particular to a gear motor. The gear motor comprises a shell, a front end cover, a rear end cover and a supporting shaft, the front end cover and the rear end cover are arranged at the two axial ends of the shell respectively, a supporting table extending towards the axis is arranged in the shell, and an outer rotor is arranged in a driving cavity. A rotating frame and a sun gear which are coaxial with the supporting shaft are sequentially arranged at the axial end, close to the supporting table, of the outer rotor, a planet carrier and an inner gear ring which are coaxial with the supporting shaft are arranged in the transmission cavity, and a duplicate gear parallel to the axis of the planet carrier is arranged in the planet carrier. An annular lip extends from the axis position of the end, close to the supporting table, of the planet carrier, a first bearing is arranged between the outer circle face of the annular lip and the inner wall of the supporting table in a matched mode, and a second bearing is arranged between the inner circle face of the annular lip and the sun gear in a matched mode. The device has the advantages that the axial length of the motor can be shortened, and the overall occupied space of the device is saved.

Description

Technical Field

[0001] This invention relates to the field of motor technology, specifically to a geared motor. Background Art

[0002] Chinese patent application No. 201610623905.3 discloses a double gear reducer, including a housing, a primary internal gear ring, a planetary disk, a double gear, a secondary internal gear ring, and a connecting gear. The primary internal gear ring is fixed to the housing, and an end cap is provided at the end of the housing. The planetary disk is mounted on the output shaft of a hydraulic motor via bearings. The double gear is mounted on the planetary disk and includes a large-diameter gear and a small-diameter gear. The connecting gear is fixed to the housing of the hydraulic motor. The secondary internal gear ring is sleeved on the connecting gear and meshes with the connecting gear. The large-diameter gear of the double gear meshes with the drive gear on the output shaft of the hydraulic motor and the primary internal gear ring.

[0003] In the above technical solution, a double gear is used as a planetary gear, and the power is transmitted to the housing through the large diameter gear in the double gear, so that it can be used as the power output end for transmission. However, in the above technical solution, since one end of the housing is supported by two bearings arranged along the axial direction of the motor, the length of the housing needs to be designed according to the two axially arranged bearings. As a result, the axial length of the motor is limited by the physical volume of the gears, bearings and other parts arranged along the axial direction, resulting in a large overall structural volume of the device and occupying space for actual assembly. Summary of the Invention

[0004] The purpose of this invention is to provide a geared motor that can shorten the overall axial length of the motor.

[0005] To achieve the above objectives, the present invention discloses a geared motor, comprising a housing, a front end cover and a rear end cover respectively disposed at both axial ends of the housing, and a support shaft. The support shaft passes through the housing and is rotatably supported at the axial center of the front end cover and the rear end cover. A support platform extending towards the axial center is provided inside the housing. The support platform divides the space inside the housing into an active cavity near the front end cover and a transmission cavity near the rear end cover. An outer rotor is provided in the active cavity. A rotating frame and a sun gear, coaxial with the support shaft, are sequentially arranged at one axial end of the outer rotor near the support platform. A planetary carrier and an inner... (the text abruptly ends here, so the translation stops here as well.) The planetary carrier is fixedly connected to the rear end of the support shaft. A double gear parallel to the axis of the planetary carrier is provided inside the planetary carrier. The sun gear passes through the central hole formed by the inner wall of the support platform and extends into the planetary carrier. The double gear meshes with the sun gear and the internal gear ring simultaneously, with the internal gear ring serving as the power output end. An annular lip extends from the axial center position of the planetary carrier near one end of the support platform. One axial end of the annular lip extends into the central hole. A first bearing is fitted between the outer circular surface of the annular lip and the inner wall of the support platform, and a second bearing is fitted between the inner circular surface of the annular lip and the sun gear.

[0006] When the outer rotor rotates, it drives the rotating frame to rotate synchronously relative to the support shaft. The rotating frame drives the sun gear to rotate synchronously relative to the support shaft. The sun gear meshes with the double gear, driving the double gear to rotate. Since the planetary carrier is keyed to the rear end of the support shaft, the double gear rotates while the gear ring rotates, which in turn causes the rear end cover, housing, and front end cover to rotate relative to the support shaft. During this process, the first bearing and the second bearing support the planetary carrier and housing respectively. The rear end cover is connected to the hub of the wheelchair wheel, thus realizing the output of power.

[0007] This invention utilizes a support platform extending towards the axis, with the active cavity and transmission cavity respectively positioned on the front and rear sides of the support platform. A first and second bearing, located in the same plane, support the annular lip on the planetary carrier, and work in conjunction with a double gear. This reduces the space occupied by gears, bearings, and other components in the axial direction, significantly shortening the axial length of the motor, reducing energy loss caused by excessively long power transmission paths, and enhancing the overall stability of the device. This also makes the device suitable for assembly scenarios with limited space. The invention has the advantages of shortening the axial length of the motor and saving overall space.

[0008] Preferably, the double gear includes a large-diameter gear and a small-diameter gear, the planet carrier has a hollow structure and an opening is provided along the radial direction of the planet carrier, the number of openings corresponds to the number of double gears, and the openings are used to allow the small-diameter gear to mesh with the gear ring.

[0009] Compared to placing the double gear at one end of the planetary carrier's axial direction, this avoids wasting axial space and allows the planetary carrier to have a hollow structure relative to a solid planetary carrier, thus reducing the weight of the planetary carrier.

[0010] Preferably, the axial length of the small diameter gear is greater than that of the large diameter gear, and the inner wall of the large diameter gear is provided with internal teeth that mesh with the teeth of the small diameter gear. The large diameter gear is sleeved on the outside of the small diameter gear part through the internal teeth.

[0011] The teeth of the small-diameter gear section act as splines for coaxial transmission, thereby achieving spline connection with the large-diameter gear section, making the entire transmission system more compact. Compared with two coaxial single gears, the double gear can provide more efficient transmission in the same space.

[0012] Preferably, the rotating frame includes a cylindrical rotating section and a turntable section located at one end of the rotating section near the support platform. The two axial ends of the rotating section are fitted with a third bearing and a fourth bearing, respectively. The end of the turntable section away from the axis is connected to the outer rotor, and the sun gear is fixedly located at the end of the turntable section near the axis.

[0013] The rotating cylinder section of the rotating frame is supported by the third and fourth bearings, thereby ensuring the stability of the rotating frame relative to the support shaft during the rotation process driven by the outer rotor.

[0014] Preferably, the turntable is provided with a countersunk groove, the opening of which faces the sun gear, and the sun gear is embedded in the turntable through the countersunk groove.

[0015] The sun gear is installed in the turntable of the rotating frame by countersunk groove, and the sun gear is coaxially limited by the circumferential groove wall of the countersunk groove and fixed with hex socket screws, which further shortens the axial length of the rotating frame and the sun gear along the axial direction of the support shaft.

[0016] Preferably, the sun gear includes a fixed section, a transition section, and a meshing section arranged sequentially along the axial direction of the support shaft. The fixed section has a disc-shaped structure, is embedded in the countersunk groove and protrudes relative to the turntable portion. The fixed section has a clearance groove at one end near the turntable portion to avoid the shoulder of the support shaft. The outer surface of the transition section mates with the second bearing. The meshing section extends into the planetary carrier and meshes with the double gear.

[0017] By making the fixed section of the sun gear protrude relative to the turntable of the rotating frame, the length required for a stable connection of the hex socket screw is ensured; the sun gear is rotated and supported by the second bearing, ensuring the stability of the sun gear during rotation relative to the support shaft.

[0018] Preferably, the transition section includes a frustum structure connected to the fixed section, with one end of the frustum structure having a large diameter connected to the fixed section, and one end of the frustum structure having a small diameter provided with a cylindrical structure, the other axial end of the cylindrical structure being connected to the meshing section.

[0019] Because the circumferential surface of the frustum structure is inclined, compared to the circumferential surface perpendicular to the surface of the fixed section, it can increase the thickness at the boundary between the fixed section and the transition section. This prevents the structural strength of the sun gear from being reduced due to the clearance groove in the fixed section, thereby ensuring the service life of the sun gear.

[0020] Preferably, the diameter of the cylindrical structure is smaller than the diameter of the smaller diameter end of the frustum structure, and stepped surfaces for axially limiting the first bearing and the second bearing are provided on both end faces of the annular lip that mate with the first bearing and the second bearing, and on the inner end face of the support platform.

[0021] Since the diameter of the cylindrical structure is smaller than the diameter of the smaller diameter end of the frustum structure, an inwardly recessed step surface is formed between the cylindrical structure and the frustum structure, which is then used to axially limit the second bearing.

[0022] Preferably, the diameter of the clearance groove is smaller than the inner diameter of the outer ring of the fourth bearing and larger than the outer diameter of the inner ring of the fourth bearing, thereby preventing interference between the sun gear and the shoulder of the support shaft or the inner ring of the fourth bearing when the rotating frame and the sun gear rotate.

[0023] Preferably, the rear end cover rotatably supports the rear end of the support shaft via a fifth bearing, and the front end cover rotatably supports the support shaft located inside the front end cover via a sixth bearing, thereby providing rotational support when the rear end cover and the front end cover rotate relative to the support shaft.

[0024] This invention can significantly shorten the axial length of the motor, optimize the power transmission path, reduce energy loss, and save the overall space occupied by the device. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of one structure of the present invention.

[0026] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0027] In the diagram: 11. Housing; 111. Support platform; 112. Third step; 12. Rear end cover; 13. Front end cover; 14. Support shaft; 15. Third bearing; 16. Fourth bearing; 17. First bearing; 18. Second bearing; 20. Outer rotor; 21. Rotating frame; 211. Rotating cylinder section; 212. Turntable section; 22. Countersunk groove; 23. Sun gear; 231. Fixed section; 232. Transition section; 233. Meshing section; 24. Socket headstock screw; 25. Double gear; 251. Large diameter gear; 252. Small diameter gear; 26. Planetary carrier; 261. First step; 262. Second step; 30. Fifth bearing; 31. Sixth bearing. Detailed Implementation

[0028] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0029] Depend on Figure 1 As shown, this embodiment discloses a geared motor, including a housing 11, a front cover 13 and a rear cover 12 respectively disposed at the axial ends of the housing 11, and a support shaft 14. The housing 11 contains a support platform with a double gear 25 extending towards the axial center. The support shaft 14 passes through a central hole formed in the inner wall of the support platform 111 and is rotatably supported at the axial center of the front cover 13 and the rear cover 12. The rear cover 12 rotatably supports the rear end of the support shaft 14 via a fifth bearing 30, and the front cover 13 rotatably supports the support shaft 14 located within the front cover 13 via a sixth bearing 31. The support platform 111 divides the space within the housing 11 into an active cavity near the front cover 13 and a transmission cavity near the rear cover 12. An outer rotor 20 is disposed in the active cavity. At one axial end of the outer rotor 20 near the support platform 111, a gear 14 is sequentially disposed with a gear 15 extending towards the support shaft 12. The planetary carrier 21 and sun gear 23 are coaxial. The transmission cavity is equipped with a planetary carrier 26 and an internal gear ring 27 coaxial with the support shaft 14. The planetary carrier 26 is connected to the rear end of the support shaft 14 by a key. The planetary carrier 26 is equipped with a double gear 25 parallel to the axis of the planetary carrier 26. The sun gear 23 passes through the central hole formed by the inner wall of the support platform 111 and extends into the planetary carrier 26. The planetary carrier 26 has an annular lip extending from the axial center position near the support platform 111. One end of the annular lip extends into the central hole. A first bearing 17 is matched between the outer circular surface of the annular lip and the inner wall of the support platform 111. A second bearing 18 is matched between the inner circular surface of the annular lip and the sun gear 23. The planetary carrier 26 has a hollow structure and has openings along the radial direction of the planetary carrier 26. The number of openings corresponds to the number of double gears 25.

[0030] The double gear 25 includes a major diameter gear 251 and a minor diameter gear 252. The major diameter gear 251 meshes with the sun gear 23. The opening of the planet carrier 26 is used to allow the minor diameter gear 252 to mesh with the gear ring. The axial length of the minor diameter gear 252 is greater than that of the major diameter gear 251. The inner wall of the major diameter gear 251 is provided with internal teeth that mesh with the teeth of the minor diameter gear 252. The major diameter gear 251 is sleeved on the outside of the minor diameter gear 252 through the internal teeth.

[0031] Depend on Figure 2 As shown, the rotating frame 21 includes a cylindrical rotating section 211 and a turntable section 212 located at one end of the rotating section 211 near the support platform 111. A third bearing 15 and a fourth bearing 16 are fitted between the axial ends of the rotating section 211 and the support shaft 14. The turntable section 212, away from the axis, is connected to the outer rotor 20. A coaxial countersunk groove 22 is formed at the center of the turntable section 212, with its opening facing the sun gear 23. The sun gear 23 includes... The fixed section 231, the transition section 232, and the meshing section 233 are arranged sequentially along the axial direction of the support shaft 14. The fixed section 231 has a disc-shaped structure. The fixed section 231 is embedded in the countersunk groove 22 and protrudes relative to the turntable part 212. The fixed section 231 has a clearance groove at one end near the turntable part 212 to avoid the shoulder of the support shaft 14. The diameter of the clearance groove is smaller than the inner diameter of the outer ring of the fourth bearing 16 and larger than the outer diameter of the inner ring of the fourth bearing 16.

[0032] The countersunk groove 22 installs the fixed section 231 of the sun gear 23 inside the turntable part 212 of the rotating frame 21, and uses hex socket screws 24 to fix the sun gear 23, thereby limiting the sun gear 23 to coaxial position through the circumferential groove wall of the countersunk groove 22.

[0033] The transition section 232 includes a frustum structure connected to the fixed section 231. The large-diameter end of the frustum structure is connected to the fixed section 231, and the small-diameter end of the frustum structure is provided with a cylindrical structure. The diameter of the cylindrical structure is smaller than the diameter of the small-diameter end of the frustum structure, thus forming an inwardly recessed structure for axially limiting the second bearing 18. The annular lip and the two end faces that match the first bearing 17 and the second bearing 18 are respectively provided with a first step 261 and a second step 262 for axially limiting the first bearing 17 and the second bearing 18. The inner end face of the support platform 111 is provided with a third step 112 for axially limiting the first bearing 17. The sun gear 23 is engaged with the second bearing 18 through the outer circular surface of the cylindrical structure. The other axial end of the cylindrical structure is connected to the meshing section 233. The meshing section 233 extends into the planet carrier 26 and meshes with the double gear 25.

[0034] When the outer rotor 20 rotates, it drives the rotating frame 21 to rotate synchronously relative to the support shaft 14. The third bearing 15 and the fourth bearing 16 provide rotational support for both ends of the rotating cylinder 211. The turntable 212 of the rotating frame 21 drives the sun gear 23 to rotate synchronously relative to the support shaft 14. The sun gear 23 drives the small diameter gear 252 to rotate by meshing with the large diameter gear 251. Since the planetary carrier 26 is keyed to the rear end of the support shaft 14, the planetary carrier 26 cannot rotate. As a result, the double gear 25 rotates, causing the internal gear ring 27 to rotate, thus outputting power. The internal gear ring 27 drives the rear end cover 12 to rotate relative to the support shaft 14. In turn, the rear end cover 12 drives the housing 11 and the front end cover 13 to rotate relative to the support shaft 14. During this process, the first bearing 17 and the second bearing 18 provide rotational support for the annular lip of the planetary carrier 26 and the support platform 111 of the housing 11, respectively. The rear end cover 12 is connected to the hub of the wheelchair wheel, thus driving the hub of the wheelchair wheel to rotate.

Claims

1. A reduction motor, comprising a housing, a front cover and a rear cover respectively arranged at the axial ends of the housing, and a support shaft, wherein the support shaft penetrates the housing and is rotatably supported at the axial center of the front cover and the rear cover, characterized in that: A support platform extending toward the axis is provided in the housing, and the support platform divides the space in the housing into an active cavity near the front end cover and a transmission cavity near the rear end cover. An outer rotor is provided in the active cavity, and a rotating frame and a sun gear coaxial with the support shaft are sequentially provided at an axial end of the outer rotor near the support platform. A planet carrier and an inner gear ring coaxial with the support shaft are provided in the transmission cavity. The planet carrier is fixedly connected to the rear end of the support shaft. A double gear parallel to the axis of the planet carrier is provided in the planet carrier. The sun gear passes through a center hole formed by the inner wall of the support platform and extends into the planet carrier. The double gear meshes with the sun gear and the inner gear ring at the same time and uses the inner gear ring as a power output end. An annular lip is extended from the axis position of the planet carrier near one end of the support platform, and an axial end of the annular lip extends into the center hole. A first bearing is matched between the outer cylindrical surface of the annular lip and the inner wall of the support platform, and a second bearing is matched between the inner cylindrical surface of the annular lip and the sun gear.

2. A reduction motor according to claim 1, characterized in that: The duplex gears include a large-diameter gear and a small-diameter gear. The planet carrier is hollow and has openings along the radial direction of the planet carrier. The number of the openings corresponds to the number of the duplex gears. The openings are used to enable the small-diameter gear to mesh with the ring gear.

3. A reduction motor according to claim 2, characterized in that: The axial length of the small diameter gear is greater than that of the large diameter gear. The inner wall of the large diameter gear is provided with internal teeth that match the gear teeth of the small diameter gear. The large diameter gear is sleeved on the outer side of the small diameter gear part through the internal teeth.

4. A reduction motor according to claim 1, 2 or 3, characterized in that: The rotating frame includes a straight cylindrical rotating cylinder portion and a turntable portion arranged at one end of the rotating cylinder portion close to the support platform, a third bearing and a fourth bearing are matched between the axial ends of the rotating cylinder portion and the support shaft, the turntable portion is connected to the outer rotor at one end away from the axis center, and the sun gear is fixedly arranged at one end of the turntable portion close to the axis center.

5. A reduction motor according to claim 4, characterized in that: The turntable portion is provided with a countersunk groove, the opening of the countersunk groove faces the sun gear, and the sun gear is embedded in the turntable portion through the countersunk groove.

6. A reduction motor according to claim 5, characterized in that: The sun gear includes a fixed section, a transition section and an engagement section which are sequentially arranged along the axial direction of the support shaft. The fixed section is a disc-shaped structure. The fixed section is embedded in the countersunk groove and protrudes relative to the turntable portion. An escape groove for avoiding the shoulder of the support shaft is provided at one end of the fixed section close to the turntable portion. The outer cylindrical surface of the transition section cooperates with the second bearing, and the engagement section extends into the planetary carrier and engages with the double gear.

7. A reduction motor according to claim 6, characterized in that: The transition section includes a frustum structure connected to the fixed section, wherein the large diameter end of the frustum structure is connected to the fixed section, and the small diameter end of the frustum structure is provided with a cylindrical structure, the outer circumferential surface of the cylindrical structure cooperates with the second bearing, and the other axial end of the cylindrical structure is connected to the meshing section.

8. A reduction motor according to claim 7, characterized in that: The diameter of the cylindrical structure is smaller than the diameter of the small diameter end of the truncated cone structure, and step surfaces for axially limiting the first bearing and the second bearing are provided on the two end surfaces of the annular lip that match the first bearing and the second bearing, and on the inner end surface of the support platform.

9. A reduction motor according to claim 6, characterized in that: The diameter of the slot opening of the air avoidance slot is smaller than the inner diameter of the outer ring of the fourth bearing and larger than the outer diameter of the inner ring of the fourth bearing.

10. The reduction motor according to claim 1, characterized in that: The rear end cover rotatably supports the rear end of the support shaft via a fifth bearing, and the front end cover rotatably supports the support shaft located inside the front end cover via a sixth bearing.

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