CN113644783B

CN113644783B - Driving device

Info

Publication number: CN113644783B
Application number: CN202110830297.4A
Authority: CN
Inventors: 林楚辉; 林建洪
Original assignee: Guangdong Jinba Intelligent Technology Co ltd
Current assignee: Guangdong Jinba Intelligent Technology Co ltd
Priority date: 2021-07-22
Filing date: 2021-07-22
Publication date: 2023-05-02
Anticipated expiration: 2041-07-22
Also published as: CN113644783A

Abstract

The invention provides a driving device, which comprises a motor and a planetary gear box, wherein the planetary gear box comprises a sun gear, a planetary wheel carrier, a plurality of planetary wheels and an inner gear ring; the motor comprises a stator and a rotor, wherein a containing cavity which is concave inwards along a motor shaft is formed in the middle of the stator; the planetary wheel carrier comprises a first wheel carrier and a second wheel carrier, and the first wheel carrier and the second wheel carrier are respectively positioned at the top end and the bottom end of the accommodating cavity; each planet wheel is positioned between and rotatably mounted to a first wheel carrier and a second wheel carrier; the inner gear ring is fixed to the accommodating cavity, and a central shaft of the sun gear axially penetrates through the accommodating cavity along the motor and is fixed with the rotation center of the rotor; the height of the planetary gear box which does not protrude from the axial end face of the motor stator or protrudes from the axial end face of the motor stator is smaller than one third of the axial height of the planetary wheel carrier. The invention reduces the volume of the driving device.

Description

Driving device

[ field of technology ]

The invention relates to the technical field of driving devices, in particular to a driving device with a motor and a planetary gear box.

[ background Art ]

Existing drive arrangements typically include a motor and a reduction gearbox. The driving device has larger volume and is difficult to be suitable for occasions with more limitation on the volume, such as joints of a robot. For this reason, a compact driving device is demanded.

[ invention ]

It is an object of the present invention to reduce the volume of the drive device.

In order to achieve the above purpose, the technical scheme provided by the invention is that the driving device comprises a motor and a planetary gear box, wherein the planetary gear box comprises a sun gear, a planetary gear carrier, a plurality of planetary gears and an inner gear ring; the motor comprises a stator and a rotor, wherein a containing cavity which is concave inwards along a motor shaft is formed in the middle of the stator; the planetary wheel carrier comprises a first wheel carrier and a second wheel carrier, and the first wheel carrier and the second wheel carrier are respectively positioned at the top end and the bottom end of the accommodating cavity; each planet wheel is positioned between and rotatably mounted to a first wheel carrier and a second wheel carrier; the inner gear ring is fixed to the accommodating cavity, the sun gear is surrounded by the plurality of planetary gears, and a central shaft of the sun gear axially penetrates through the accommodating cavity along the motor and is fixed with the rotation center of the rotor so as to enable the sun gear and the rotor to synchronously rotate; the height of the planetary gear box which does not protrude from the axial end face of the motor stator or is basically level with the axial end face of the motor stator or protrudes from the axial end face of the motor stator is less than one third of the axial height of the first wheel frame to the second wheel frame.

In one embodiment of the invention, the reduction ratio of the planetary gearbox is 15:1 to 60:1.

In one embodiment of the present invention, the first wheel frame and the second wheel frame are fixedly connected as a whole to perform synchronous rotation.

In one embodiment of the invention, the stator is directly or indirectly rollingly supported by the central shaft, enabling the sun gear and rotor to rotate relative to the stator.

In one embodiment of the present invention, the stator includes an annular yoke, stator teeth protruding outward from the annular yoke, stator windings wound to the stator teeth, the annular yoke forming the receiving cavity and being fixed with the ring gear; the rotor comprises an annular iron core, permanent magnets and a rotor bracket; the annular iron core surrounds the radial outer side of the annular magnetic yoke and at least partially overlaps with the annular magnetic yoke in the axial direction of the motor; the permanent magnet is fixed on the inner wall of the annular iron core, and an air gap exists between the permanent magnet and the stator teeth; the central part of the rotor support is fixed with the central shaft of the sun gear, and the outer end of the rotor support is connected to the annular iron core.

In one embodiment of the present invention, the stator includes an upper case and a lower case, and the annular yoke and the annular core are accommodated in a space surrounded by the upper case and the lower case; the middle part of the lower shell passing through the lower shell rolls and supports the central part of the rotor bracket; the annular yoke and the ring gear are fixed to an inner wall of the upper case, and the upper case rollingly supports a central shaft of the sun gear.

In one embodiment of the invention, a first end of a central shaft of the sun gear is fixed to a central portion of the rotor holder, and a second end is rollingly supported by the upper case through the planetary carrier.

In one embodiment of the invention, the central shaft of the sun gear is rollingly supported from a first end to a second end by a first bearing mounted to the center of the lower housing, a second bearing mounted to the center of the second wheel carrier, and a third bearing mounted to the center of the first wheel carrier, respectively.

In one embodiment of the present invention, an outer side of the second wheel frame is supported by a fourth bearing, an outer side of the first wheel frame is supported by a fifth bearing, and the fourth bearing and the fifth bearing are mounted to the upper case, the annular yoke, or the ring gear.

In one embodiment of the invention, the rotor support comprises an outer support and an inner support, wherein the central part of the inner support is fixedly connected with the central shaft of the sun gear, and the outer support is in a plane annular shape and is connected between the inner support and the rotor core.

By implementing the invention, the planetary gear box of the driving device can be flush with the motor stator, the structure is compact, and the volume is reduced.

[ description of the drawings ]

FIG. 1 is a schematic diagram of a driving device according to an embodiment of the present invention;

FIG. 2 is a schematic side view of the drive apparatus of FIG. 1;

FIG. 3 is a cross-sectional view of the drive device of FIG. 2 taken along the A-A plane;

FIG. 4 is a schematic view of the drive device of FIG. 1 with the upper housing removed, showing the top construction of the drive device;

FIG. 5 is a schematic view of the drive device of FIG. 4 with the lower housing removed, showing the bottom structure of the drive device;

FIG. 6 is a schematic view of a sun gear and inner rotor carrier for use with the drive apparatus of FIG. 5;

FIG. 7 is a schematic view of the drive device of FIG. 5 with the sun gear and rotor removed, showing the top construction of the remaining components (stator and a portion of the planetary gearbox);

FIG. 8 shows the bottom structure of the assembly of FIG. 7;

FIG. 9 is a schematic view of the assembly of FIG. 7 with the first carrier removed, showing the internal structure of the planetary gearbox;

fig. 10 and 11 are schematic views of a first carrier and a second carrier, respectively, of a planetary gear box used in the driving device shown in fig. 1.

[ detailed description ] of the invention

The invention is further described below with reference to the drawings and examples.

Referring to fig. 1, in one embodiment of the present invention, a driving apparatus 100 is provided that includes a housing formed of an upper case 11 and a lower case 13, a motor and a planetary gear box mounted into the housing. After the planetary gear box decelerates the output of the motor, the motor is driven to the outside through the planetary carrier (the first carrier 31). A terminal or cable 15 extends from the lower housing 13 for connection to an external power source for powering the drive device 100.

Referring to fig. 1 and 2, the driving device 100 is a flat cylinder, and the planetary gear box and its first wheel carrier 31 are substantially flush with the housing. This design improves the compactness of the drive device 100. In this embodiment, the upper case 11 is cylindrical, the lower case 13 is planar, and the outer edge of the lower case 13 is fixed to the annular wall of the upper case 11 by a fastener 14 (see fig. 4) such as a screw.

Referring to fig. 2 to 11, the planetary gear box includes a sun gear 21, a plurality of planet gears 23, an inner gear ring 27, and a planet carrier composed of a first carrier 31 and a second carrier 33. Sun gear 21 is housed in ring gear 27 and surrounded by ring gear 27. A plurality of planet gears 23 surround the sun gear 21 and are surrounded by an inner gear ring 27, the planet gears 23 simultaneously meshing with the sun gear 21 and the inner gear 27. The first and

second carriers

31 and 33 are located at both axial ends of the planetary gears 23, respectively, and each planetary gear 23 is rotatably mounted to the first and

second carriers

31 and 33 between the first and

second carriers

31 and 33. In the present embodiment, the planetary gears 23 are mounted to the corresponding planetary shafts 25, and both ends of the planetary shafts 25 are mounted to the first carrier 31 and the second carrier 33, respectively. Thus, when the sun gear 21 rotates, the planetary gears 23 are revolved around the sun gear 21, thereby rotating the first and

second carriers

31 and 33.

The motor includes a stator and a rotor. The middle part of the stator is provided with a containing cavity which is concave inwards along the motor shaft, and the planetary gear box is at least partially arranged in the containing cavity, so that the planetary gear box is at least partially overlapped with the stator in the motor shaft direction. In this embodiment, the stator includes an annular yoke 51, stator teeth 53 protruding outward from the annular yoke 51, and stator windings 55 wound to the stator teeth 53. A slot is formed between adjacent stator teeth 53 and the stator windings 55 partially drop into the corresponding slot. The annular yoke 51 forms the above-described housing cavity to which the ring gear 27 is fixed. The annular yoke 51, the ring gear 27, and the upper case 11 are fixed together.

The rotor includes a ring-shaped iron core 71, permanent magnets 72 mounted to an inner wall of the ring-shaped iron core 71, and a rotor bracket connecting the ring-shaped iron core 71 to a central axis of the sun gear 21, a central portion 77 of the rotor bracket being fixedly sleeved to the central axis of the sun gear 21 to achieve synchronous rotation, that is, to directly drive the sun gear 21 by the rotor. The annular iron core 71 surrounds the radial outside of the annular yoke 51 and at least partially overlaps the annular yoke 51 in the motor shaft direction. An air gap exists between the permanent magnets 72 and the stator teeth 53 to enable the rotor to rotate relative to the stator. In this embodiment, the permanent magnet 72 is composed of a plurality of permanent magnets of sintered neodymium iron boron, which are uniformly distributed along the circumferential direction of the rotor core 71, each permanent magnet forming one pole of the rotor. The permanent magnet block can improve the working temperature resistance of the permanent magnet.

Preferably, the number of stator slots is 36 or 48 and the number of poles of the rotor is 24 or 46. The slot pole collocation has higher efficiency.

The rotor support comprises a detachable outer support 74 and an inner support 75. The inner bracket 75 is in a plane circular body shape, and the central part 77 is fixedly sleeved on the central shaft of the sun gear 21. The outer bracket 74 is a planar ring body, and is connected between the inner bracket 75 and the rotor core 71. The rotor support is formed by the detachable outer support 74 and inner support 75, which is helpful for the assembly of the product and improves the production efficiency.

In this embodiment, as shown in fig. 5 and 6, the center portion 77 of the inner holder 75 is cylindrical and fixedly fitted to the center axis of the sun gear 21. The inner support 75 includes a plurality of first spokes extending outwardly from the center 77, and a first outer ring connected to outer ends of the plurality of first spokes. And the outer bracket 77 includes a first inner ring body, a plurality of second spokes extending outwardly from the first inner ring body, and a second outer ring body connected to outer ends of the plurality of second spokes. The first inner ring body overlaps the first outer ring body, and the first inner ring body and the first outer ring body are detachably connected through fasteners such as screws. The second outer ring body is fixedly connected with the annular iron core 71.

As shown in fig. 3, a first end of the central shaft of the sun gear 21 passes through a receiving cavity formed by the annular yoke 51 along the motor axial direction and is fixed to the central portion 77 of the rotor inner bracket 75, so that the sun gear 21 and the rotor can rotate synchronously. The center portion 77 is rollingly supported by a first bearing 81 and a second bearing 83 on both sides of the inner bracket 75, respectively, the first bearing 81 being mounted to the center of the lower shell 13, and the second bearing 83 being mounted to the center of the second wheel frame 33. The second end of the central shaft of the sun gear 21 is rollingly supported by a third bearing 85, the third bearing 85 being mounted to the center of the first wheel carrier 31.

The outer side of the second wheel frame 31 is supported by the fourth bearing 87, and the outer side of the first wheel frame 31 is supported by the fifth bearing 89. The fourth bearing 87 and the fifth bearing 89 may be mounted to the annular yoke 51 and the upper case 11, respectively. Understandably, because the annular yoke 51, the upper case 11 and the ring gear 27 are fixed together, one or both of them can be mounted with the fourth bearing 87 and the fifth bearing 89 to achieve similar effects. Preferably, the fourth bearing 87 is supported by the annular yoke 51 and the ring gear 27 together, and the fifth bearing 89 is supported by the ring gear 27 and the upper case 11 together, so as to strengthen concentricity of the annular yoke 51, the ring gear 27, and the upper case 11.

Referring to fig. 9 to 11, the first carrier 31 and the second carrier 33 are fixedly coupled as an integral planetary carrier for synchronous rotation. Specifically, the first wheel carrier 31 is ring-shaped, including an annular main body 3301. The second wheel frame 33 includes an annular body 3301, and a plurality of support parts 3304 located on one end surface of the annular body 3301. When assembled, the support portion 3304 abuts against the annular body 3301 of the first wheel frame 31. Preferably, the supporting portion 3304 is provided with a connection hole 3305, and the annular main body 3301 of the first wheel frame 31 is also provided with a connection hole 3105 at a corresponding position, and both are positioned and connected by an axial pin 3306. Further, an arc-shaped flange 3307 is provided on the outer side of the supporting portion 3304, and the annular body 3301 of the first wheel frame 31 is concaved into a positioning step 317 at a corresponding position, and the arc-shaped flange 3307 cooperates with the positioning step 317 to enhance coaxiality of the two.

The plurality of support portions 3304 are distributed at intervals along the circumferential direction of the annular main body 3301, and spaces for accommodating the planetary gears 23 are formed between adjacent support portions 3304. Specifically, the annular main body 3301 of the first carrier 31, the annular main body 3301 of the second carrier 33 are provided with

shaft holes

3103 and 3303, respectively, at positions offset from the support portion 3304, and both ends of the planetary shaft 25 of the planetary gear 22 are mounted to the shaft holes 3103 and 3303, respectively.

In this embodiment, the housing cavity is provided in the middle of the stator for mounting the planetary gear box, and the planetary gear box is substantially flush with the axial end surface of the motor stator, so that a very compact, flat driving device is obtained. In an alternative embodiment, the planetary gearbox does not protrude from the axial end face of the motor stator. In another alternative embodiment the planetary gearbox protrudes slightly beyond the axial end face of the motor stator, but the protruding height is less than one third of the axial height of the first wheel carrier 31 to the second wheel carrier 33, preferably not more than one fourth of the axial height of the first wheel carrier 31 to the second wheel carrier 33.

Preferably, the reduction ratio of the planetary gearbox is 15:1 to 60:1.

The foregoing examples only illustrate preferred embodiments of the invention, which are described in more detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that modifications and improvements can be made without departing from the spirit of the invention, such as combining different features of the various embodiments, which are all within the scope of the invention.

Claims

1. The driving device comprises a motor and a planetary gear box, wherein the planetary gear box comprises a sun gear, a planetary gear carrier, a plurality of planetary gears and an inner gear ring, and is characterized in that the motor comprises a stator and a rotor, and a containing cavity which is inwards concave along a motor shaft is formed in the middle of the stator; the planetary wheel carrier comprises a first wheel carrier and a second wheel carrier, and the first wheel carrier and the second wheel carrier are respectively positioned at the top end and the bottom end of the accommodating cavity; each planet wheel is positioned between and rotatably mounted to a first wheel carrier and a second wheel carrier; the inner gear ring is fixed to the accommodating cavity, the sun gear is surrounded by the plurality of planetary gears, and a central shaft of the sun gear axially penetrates through the accommodating cavity along the motor and is fixed with the rotation center of the rotor so as to enable the sun gear and the rotor to synchronously rotate; the stator is indirectly supported by the central shaft in a rolling way, so that the sun gear and the rotor can rotate relative to the stator; the stator comprises an annular magnetic yoke, stator teeth extending outwards from the annular magnetic yoke and stator windings wound on the stator teeth, and the annular magnetic yoke forms the accommodating cavity and is fixed with the annular gear; the rotor comprises an annular iron core, permanent magnets and a rotor bracket; the annular iron core surrounds the radial outer side of the annular magnetic yoke and at least partially overlaps with the annular magnetic yoke in the axial direction of the motor; the stator comprises an upper shell and a lower shell, and the annular magnetic yoke and the annular iron core are accommodated in a space surrounded by the upper shell and the lower shell; the middle part of the lower shell passing through the lower shell rolls and supports the central part of the rotor bracket; the annular magnetic yoke and the annular gear ring are fixed to the inner wall of the upper shell, and the upper shell rollingly supports the central shaft of the sun gear; the central shaft of the sun gear is respectively supported by a first bearing, a second bearing and a third bearing from a first end to a second end, the first bearing is mounted to the center of the lower shell, the second bearing is mounted to the center of the second wheel frame, and the third bearing is mounted to the center of the first wheel frame; the outer side of the second wheel frame is supported by a fourth bearing, the outer side of the first wheel frame is supported by a fifth bearing, and the fourth bearing and the fifth bearing are mounted to the upper case, the annular yoke or the ring gear; the annular magnetic yoke and the annular gear ring jointly support a fourth bearing, and the annular gear ring and the upper shell jointly support a fifth bearing; the height of the planetary gear box which does not protrude from the axial end face of the motor stator or is basically level with the axial end face of the motor stator or protrudes from the axial end face of the motor stator is less than one third of the axial height of the first wheel frame to the second wheel frame.

2. The drive of claim 1, wherein the reduction ratio of the planetary gearbox is 15:1 to 60:1.

3. The driving device as recited in claim 1 wherein said first and second wheel frames are fixedly connected as a unit for synchronous rotation.

4. The drive of claim 1, wherein the permanent magnets are fixed to an inner wall of the toroidal core with an air gap between the permanent magnets and the stator teeth; the central part of the rotor support is fixed with the central shaft of the sun gear, and the outer end of the rotor support is connected to the annular iron core.

5. The drive device according to claim 4, wherein a first end of a central shaft of the sun gear is fixed to a central portion of the rotor holder, and a second end is rollingly supported by the upper case through the carrier.

6. The drive of claim 4, wherein the rotor support comprises an outer support and an inner support, a central portion of the inner support is fixedly connected with a central shaft of the sun gear, and the outer support is in a planar annular shape and is connected between the inner support and the rotor core.