CN115163760A

CN115163760A - Planetary gear assembly with clutch as support

Info

Publication number: CN115163760A
Application number: CN202211009946.5A
Authority: CN
Inventors: 温群峰
Original assignee: Suzhou Shengyi Motor Co ltd
Current assignee: Suzhou Shengyi Motor Co ltd
Priority date: 2022-08-23
Filing date: 2022-08-23
Publication date: 2022-10-11

Abstract

The invention discloses a planetary gear assembly with a clutch as a support, which comprises the clutch and a plurality of planetary gears, wherein the clutch comprises an outer ring and an inner ring, each planetary gear is arranged on a corresponding planetary shaft, and the planetary shafts are fixed on the outer ring of the clutch; the planetary gears are duplicate gears and comprise a large gear and a small gear which are coaxially arranged, and the small gear is arranged towards the clutch; the clutch is characterized in that the end face of the outer ring of the clutch is provided with abdicating concave cavities corresponding to the planetary gears for the pinion to be embedded into, and the periphery of the outer ring is provided with openings corresponding to the abdicating concave cavities for the peripheral teeth of the pinion to radially protrude out of the outer ring. The axial size of the motor is smaller, the structure is more compact, and the motor can be adapted to a motor with smaller overall axial size design and more compact internal space.

Description

Planetary gear assembly with clutch as support

Technical Field

The invention relates to a planetary gear assembly with a clutch as a support.

Background

The planetary reduction mechanism and the clutch are important components in a motor transmission mechanism of a hub motor or a central motor, the planetary reduction mechanism mainly comprises a planetary gear assembly and a sun gear, and a plurality of planetary gears in the planetary gear assembly are arranged on a support through planetary shafts and then meshed with the sun gear on the output end of a rotor of the motor. The clutch is generally connected with the output end of the planetary reduction mechanism, and then assembled with an output transmission member of the motor, such as an internal gear ring of the hub motor or a chain wheel output mechanism of the middle-mounted motor.

In the original motor transmission mechanism, the clutch is usually assembled separately from the planetary reduction mechanism, but with the improvement of technology, in order to simplify the structure of the internal transmission mechanism and make it more compact, more and more motor products will usually integrate the planetary gear assembly and the clutch in the planetary reduction mechanism, in this assembly structure, the clutch is used as the support to support and assemble the planetary gear.

Taking a conventional through-shaft type in-wheel motor as an example, the machine core (comprising a stator and a rotor), the planetary reduction mechanism and the clutch are assembled in sequence along the through shaft. The clutch comprises an outer ring and an inner ring, wherein the inner ring is fixed to the through shaft and the planet shaft in the center of the planet gear is directly fixed to the clutch outer ring. The output end of the rotor of the machine core is fixed with a sun gear sleeved on the through shaft, and the sun gear is in transmission connection with a gear ring fixed on the inner side of the hub shell through a plurality of planet gears in the planet speed reducing mechanism. In a further refinement, the planet gears are usually formed as an integrally formed double gear, with a large gear engaging the sun gear and a small gear engaging the ring gear.

It can be said that many companies in the industry have produced the above-described clutch-supported planetary gear assembly as a standard component to enable quick fitting into a suitable motor drive. However, in actual use, the existing planetary gear assemblies of this type are exposed to the following problems:

because the planetary gear and the clutch are directly and simply assembled axially, the axial size of the planetary gear assembly taking the clutch as a support is not optimized and reduced, and accordingly, the planetary gear assembly cannot be adapted to a motor with smaller overall axial size and compact inner space. In the prior art, a motor is manufactured and applied to a road electric power-assisted bicycle, and the industry has higher production requirements on the aspects of the overall weight, the volume, the structural strength and the output power of the motor.

Furthermore, it should be noted that in order to further reduce the mass of the assembly, the prior art planetary gears are often made of plastic duplicate gears integrally molded from a single plastic, such as POM (polyoxymethylene) plastic, PEEK (polyetheretherketone) plastic, and nylon plastic, such as PA66 and PA46, but inevitably suffer from a reduction in structural strength. In order to make up for the defect, the plastic duplicate gear is usually made thicker and larger to enhance the structural strength, however, when the diameter of the large gear in the duplicate gear is increased, the rotating speed ratio of the large gear to the sun gear at the output end of the rotor is reduced, and finally the overall output power of the motor is reduced.

And after the whole size of planetary gear increases, need the bigger motor of adaptation external diameter size, finally lead to corresponding motor volume increase, the material quantity increases, and weight grow, the cost becomes high.

Disclosure of Invention

The invention aims to: the planetary gear assembly with the clutch as the support is smaller in axial size and more compact in structure, and can be adapted to a motor with smaller overall axial size and more compact inner space.

The technical scheme of the invention is as follows: a planetary gear assembly taking a clutch as a support comprises the clutch and a plurality of planetary gears, wherein the clutch comprises an outer ring and an inner ring, each planetary gear is arranged on a corresponding planetary shaft, and the planetary shafts are fixed on the outer ring of the clutch; the planetary gears are duplicate gears and comprise a large gear and a small gear which are coaxially arranged, and the small gear is arranged towards the clutch; the clutch is characterized in that the end face of the outer ring of the clutch is provided with abdicating cavities corresponding to the planetary gears, and the outer periphery of the outer ring is provided with openings corresponding to the abdicating cavities so that the peripheral teeth of the pinion can radially protrude out of the outer ring.

Furthermore, the large gear and the small gear of the planetary gear are arranged in a split mode, wherein the large gear is a plastic gear, the small gear is a metal gear, and the center of the small gear is integrally provided with an extending shaft sleeve for fixing the large gear.

Furthermore, the large gear is injection molded and fixed on the periphery of the extension shaft sleeve of the small gear, or the large gear is matched and embedded on the periphery of the extension shaft sleeve of the small gear through a key groove structure.

Furthermore, the pinion extension sleeve is mounted on the planet shaft via a plurality of planet bearings.

Preferably, the planet bearing in the invention adopts a sliding bearing. Compared with a deep groove ball bearing, the radial size of the planetary gear can be further reduced by adopting the sliding bearing, the overall radial size of the motor rotor is reduced, and further, after the planetary gear is matched with a motor, the rotating speed ratio of the large gear to the sun gear at the output end of the motor rotor can be improved, so that the overall power of the motor can be improved. The size of the motor adapted thereto can be reduced as well.

Furthermore, the planetary gears are distributed in a centrosymmetric mode around the center of the clutch, and the number of the planetary gears is more than 3.

Furthermore, the inner circumference of the inner ring of the clutch is milled with a positioning groove for implementing assembly and fixation with a shaft milled with a spline, such as rapid assembly and fixation to a through shaft of a hub motor or a middle shaft of a middle motor.

The invention is actually used as a component of the existing motor transmission mechanism, taking a known through-shaft type hub motor as an example, the motor is provided with a through shaft and a hub shell, wherein two ends of the hub shell are both arranged on the through shaft through shell bearings, and a machine core, a sun gear and the planetary gear assembly are sequentially assembled along the through shaft in the hub shell. The machine core adopts an inner stator and outer rotor structure, the sun gear and the rotor are fixed and sleeved on the through shaft, and the sun gear and the rotor are in transmission connection with the gear ring fixed on the inner side of the hub shell through the planet gear.

When the clutch is assembled, the inner ring of the clutch is fixed on the through shaft, the big gear in the planetary gear is a plastic gear and is meshed with the sun gear, the small gear is a metal gear, and the center of the small gear is integrally provided with an extending shaft sleeve for fixing the big gear; the end face of the outer ring of the clutch is provided with abdicating cavities corresponding to the planetary gears, and the outer periphery of the outer ring is provided with openings corresponding to the abdicating cavities, so that the outer peripheral tooth parts of the pinion protrude radially to be meshed with the gear ring. In such motors, it is often further provided that the ring gear is also provided as a plastic ring gear, in order to further reduce the weight and the noise when it meshes with a metal pinion.

It should be noted that, the plastic gear wheel of the present invention can be any conventional plastic material in the industry, such as POM (polyoxymethylene) plastic, PEEK (polyetheretherketone) plastic, and nylon plastic, such as PA66 and PA 46.

The pinion gear of the metal gear is made of any conventional common material in the industry, such as alloy steel of 40Cr, 45 Cr, 20CrMnTi and the like, and conventional copper alloy (such as brass) and aluminum alloy and the like, and the forming mode of the pinion gear can be milling, forging, cold extrusion, drawing, powder metallurgy and the like.

The invention has the advantages that:

1. the invention has the advantages that the abdicating concave cavities for the pinion to be embedded into are arranged on the outer ring end surface of the clutch corresponding to the planetary gears, so that the axial length of the whole clutch can be further reduced compared with the existing product, the structure is more compact, and the clutch can be adapted to the motor with smaller whole axial size design and more compact internal space. Similarly, the planetary gear assembly is also beneficial to designing a motor product which is adaptive and has smaller volume and more compact internal structure, so that the production material is saved, the weight is reduced, and the production cost is reduced.

2. The planetary gear is different from the existing integrally manufactured plastic duplicate gear, the large gear and the small gear are arranged in a split mode, the large gear is made of the plastic gear and can reduce the overall weight of the planetary gear, the small gear is made of the metal gear and is fixed with the large gear through the integrally arranged extending shaft sleeve, the structure enables the small gear to have strength and can also provide certain supporting strength for the large gear, the large gear does not need to be large in outer diameter and thickness to increase the strength like the conventional technology, on the contrary, the outer diameter size can be further reduced, the large gear and a rotor output end sun gear in an adaptive motor are guaranteed to have a high rotating speed ratio, the overall output power of the motor is further improved, and the motor can meet the application requirements of a road electric power-assisted bicycle.

3. Also, because the metal pinion in the structural design of the planetary gear can provide enough supporting strength for the gearwheel, the external diameter size and the thickness size of the gearwheel can be further reduced, which is beneficial to reducing the radial and axial sizes of the whole adaptive motor, thereby reducing the volume and weight of the whole motor and enabling the motor to better meet the application requirements of the road electric power-assisted bicycle.

4. Compared with a deep groove ball bearing, the sliding bearing is adopted to further reduce the radial size of the planetary gear and the overall radial size of the motor rotor, and further after the planetary shaft is matched with a motor, the rotating speed ratio of the large gear to the sun gear at the output end of the motor rotor can be improved, so that the overall power of the motor can be improved. The size of the motor adapted thereto can be reduced as well.

Drawings

The invention is further described with reference to the following figures and examples:

FIG. 1 is a front view of the present invention;

FIG. 2 is a right side view of FIG. 1;

FIG. 3 isbase:Sub>A cross-sectional view taken along line A-A of FIG. 1;

FIG. 4 is a schematic representation of an isolated perspective view of the clutch of FIG. 1 (with the planet shafts);

FIG. 5 is a front elevational view of the clutch of FIG. 1;

FIG. 6 is a cross-sectional view of the through-shaft hub motor of the present invention in use.

Wherein: 1. a clutch; 101. an outer ring; 101a, a yielding cavity; 101b, an opening; 102. an inner ring; 102a, a positioning groove; 2. a planetary gear; 201. a bull gear; 202. a pinion gear; 202a, an extension shaft sleeve; 3. a planet shaft; 4. a planetary bearing; 5. passing through the shaft; 6. a housing bearing; 7. a hub shell; 8. a stator; 9. a rotor; 10. a sun gear; 11. a ring gear.

Detailed Description

Example (b): the following describes a specific embodiment of the planetary gear assembly with a clutch as a carrier according to the present invention with reference to fig. 1 to 6 as follows:

first, as shown in fig. 1, the present embodiment is composed of a clutch 1, three planetary gears 2, three planetary shafts 3, and six planetary bearings 4. The clutch 1 has an outer race 101 and an inner race 102 as in the conventional art, and each planetary gear 2 is provided on a corresponding planetary shaft 3, and the planetary shafts 3 are vertically fixed to the outer race 101 of the clutch 1. The three planet gears 2 are arranged in a centrosymmetric manner with respect to the center of the clutch 1.

Referring to fig. 2 to 5, the planetary gears 2 are all duplicate gears, and include a large gear 201 and a small gear 202 coaxially disposed, and the small gear 202 is disposed facing the clutch. The core improvement of the present invention is that the end surface of the outer ring 101 of the clutch 1 is provided with a relief cavity 101a for the pinion 202 to be inserted into corresponding to each planetary gear 2, and the outer periphery of the outer ring 101 is provided with an opening 101b corresponding to each relief cavity 101a for the outer peripheral teeth of the pinion 202 to radially protrude out of the outer ring 101.

Meanwhile, in this embodiment, the bull gear 201 is a plastic gear, and the pinion gear 202 is a metal gear, and an extending shaft sleeve 202a is integrally formed at the center thereof to fix the bull gear 201. In this embodiment, the bull gear 201 is injection molded and press-fixed to the periphery of the extension sleeve 202a of the pinion gear 202.

The extension sleeve 202a of each pinion 202 is assembled on the planetary shaft 3 through two planetary bearings 4, and the planetary bearings 4 are sliding bearings.

Meanwhile, in the present embodiment, the inner race 102 of the clutch 1 is milled with the positioning grooves 102a on the inner circumference, as shown in fig. 1, 4, and 5.

The present example is further described below in connection with the application as follows:

the planetary gear assembly with the clutch as the carrier is actually used as a component of the existing motor transmission mechanism. Referring to fig. 6, taking as an example the application thereof to a known through-shaft type hub motor, the motor has a through-shaft 5 and a hub housing 7 mounted on the through-shaft 5 at both ends thereof through housing bearings 6, and the hub housing 7 is internally provided with a core, a sun gear 10 and a planetary gear assembly of the present invention assembled in sequence along the through-shaft 5. The movement adopts an inner stator 8 and outer rotor 9 structure, a sun gear 10 and the rotor 9 are fixed and sleeved on the through shaft 5, and the sun gear and the rotor are in transmission connection with a gear ring 11 fixed on the inner side of a hub shell 7 through a planetary gear 2 in the invention.

During specific assembly, the inner ring 102 of the clutch 1 is clamped with a key milled on the through shaft 5 through a positioning groove 102a on the inner ring, so that the inner ring is fixed on the through shaft 5, a large gear 201 in the planetary gear 2 is a plastic gear and is meshed with the sun gear 10, a small gear 202 is a metal gear, and an extending shaft sleeve 202a is integrally arranged at the center of the small gear to fix the large gear 201; the clutch 1 has a relief recess 101a in an end surface of the outer ring 101 for each pinion gear 2 to be fitted therein, and an opening 101b in an outer periphery of the outer ring 101 for each relief recess 101a, in which an outer peripheral tooth portion of the pinion gear 202 is radially projected so as to be engaged with the ring gear 11. In such motors, the ring gear 11 is also often provided as a plastic ring gear to further reduce the weight and reduce the noise when it meshes with the metal pinion 202. The plastic bull gear 201 is meshed with the metal sun gear 10 at the output end of the conventional rotor 9, so that the noise is reduced, and the overall working noise of the through shaft type hub motor is greatly reduced.

In the embodiment, the plastic used for actually producing the large gear 201 and the ring gear 11 serving as plastic gears is nylon plastic PA66 which is commonly used at present, and the small gear 202 and the sun gear 10 serving as metal gears are manufactured by 40Cr alloy steel which is commonly used in the industry through a powder metallurgy process.

In the embodiment, the abdicating cavities 101a for the pinion gears 202 to be embedded into are arranged on the end face of the outer ring 101 of the clutch 1 corresponding to the planet gears 2, so that compared with the existing product, the axial length of the whole can be further reduced, the structure is more compact, and the planetary gear assembly can be adapted to a motor with smaller whole axial size design and more compact internal space.

The planet gear 2 in the embodiment is different from the existing integrally manufactured plastic duplicate gear, the large gear 201 and the small gear 202 are separately arranged, the large gear 201 adopts a plastic gear to reduce the overall weight of the planet gear 2, the small gear 202 adopts a metal gear and the large gear 201 is fixed by the extending shaft sleeve 202a integrally arranged on the metal gear, the structure ensures that the small gear 202 has strength and can also provide certain supporting strength for the large gear 201, the large gear 201 does not need to enlarge the outer diameter and the thickness to increase the strength like the conventional technology, but can further reduce the outer diameter, thereby ensuring that the large gear has higher rotation speed ratio with the sun gear 10 at the output end of the rotor 9 of the through shaft type hub motor, the overall output power of the motor is further improved, and the motor can better meet the application requirements of the road electric power-assisted bicycle.

Also, since the metal pinion 202 in the planetary gear structure design of the present embodiment can give enough supporting strength to the bull gear 201, the outer diameter size and the thickness size of the bull gear 201 can be further reduced, which is beneficial to reducing the radial and axial sizes of the whole through-shaft hub motor adapted as described above, thereby reducing the volume and weight of the whole motor, so that the motor can better meet the application requirements of the road electric power-assisted bicycle.

And the planet shaft 3 adopts the sliding bearing to support the pinion 202 and the extension shaft sleeve 202a thereof, compared with a deep groove ball bearing, the sliding bearing can further reduce the size of the planet gear 2 in the radial direction and the overall radial size of the invention, and further after the sliding bearing is matched with a motor, the rotating speed ratio of the large gear 201 and the sun gear 10 at the output end of the motor rotor 9 can be improved, so that the overall power of the motor can be improved. The size of the motor adapted thereto can be reduced as well.

It should be understood that the above-mentioned embodiments are only illustrative of the technical concepts and features of the present invention, and are intended to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the scope of the present invention. All modifications made in accordance with the spirit of the main technical scheme of the invention are intended to be covered by the scope of the invention.

Claims

1. A planetary gear assembly with a clutch as a support comprises the clutch (1) and a plurality of planetary gears (2), wherein the clutch (1) comprises an outer ring (101) and an inner ring (102), each planetary gear (2) is arranged on a corresponding planetary shaft (3), and the planetary shafts (3) are fixed on the outer ring (101) of the clutch (1); the planetary gears (2) are all duplicate gears and comprise a large gear (201) and a small gear (202) which are coaxially arranged, and the small gear (202) is arranged towards the clutch; the clutch is characterized in that an abdicating cavity (101 a) for the pinion (202) to be embedded into is arranged on the end face of the outer ring (101) of the clutch (1) corresponding to each planet gear (2), and an opening (101 b) is arranged on the periphery of the outer ring (101) corresponding to each abdicating cavity (101 a) so that the peripheral teeth of the pinion (202) radially protrude out of the outer ring (101).

2. A planetary gear assembly with a clutch as carrier according to claim 1, characterized in that the large gear (201) is a plastic gear and the small gear (202) is a metal gear, and an extension sleeve (202 a) is integrally formed at the center thereof to fix the large gear (201).

3. A planetary gear assembly with a clutch as carrier according to claim 2, characterized in that the large gear (201) is injection molded and press-fixed on the periphery of the extension sleeve (202 a) of the small gear (202), or the large gear (201) is fitted on the periphery of the extension sleeve (202 a) of the small gear (202) by a key way structure.

4. A clutch-carrier planetary gear assembly according to claim 2, characterized in that the extension sleeve (202 a) of the pinion (202) is fitted on the planet shaft (3) by means of a number of planet bearings (4).

5. A clutch-carrier planetary gear assembly according to claim 4, characterized in that the planetary bearings (4) use sliding bearings.

6. A clutch-carrier planetary gear assembly according to claim 1, characterized in that the planet gears (2) are arranged in a centrosymmetric manner with respect to the center of the clutch (1) and the number is more than 3.

7. A clutch-carrier planetary gear assembly according to claim 1, characterized in that the inner race (102) of the clutch (1) is milled with locating recesses (102 a) on its inner circumference.