CN219345403U - Gear speed reducing mechanism of hub motor - Google Patents

Abstract

The utility model provides a wheel hub motor gear speed reducing mechanism, which comprises: the device comprises a main shaft, an eccentric sleeve, a bearing, a duplex planetary gear, an output gear ring, an external fixed gear and a isolator; the double planetary gear comprises a planetary gear shell, wherein a planetary external gear is arranged on the outer surface of one end of the planetary gear shell, a planetary internal gear is arranged in the inner cavity of the other end of the planetary gear shell, and the inner cavity of the planetary external gear is sleeved outside the bearing and is fixed with the outer surface of the bearing; the planetary internal gear is sleeved outside the external fixed gear and meshed with the external fixed gear in involute small tooth difference mode to form a first gear pair; the outer part of the planetary external gear is sleeved with an output gear ring which is meshed with the output gear ring in an involute small tooth difference mode, so that a second gear pair is formed. The hub motor gear reduction mechanism provided by the utility model has the advantages of high transmission ratio, high bearing capacity, small volume, high reliability and easiness in installation and assembly.

Description

Gear speed reducing mechanism of hub motor

Technical Field

The utility model relates to a speed reducing mechanism, in particular to a gear speed reducing mechanism of an in-wheel motor.

Background

An electric bicycle hub motor is a device that converts electrical energy into mechanical motion, thereby driving a wheel forward. The common electric bicycle hub motor mainly comprises: the device comprises a main shaft, a planetary reduction mechanism, a rotor and a stator. The planetary reduction mechanism comprises a gear ring, a planetary gear and a sun gear. Mainly comprises two structural forms:

first kind: the main shaft through structure: the structure principle is as follows: the main shaft is completely communicated from left to right and is fixedly connected with the bicycle rear fork, and is completely fixed and not rotated. The sun gear needs to be provided with an inner hole for the spindle to pass through, and then the sun gear is sleeved outside the spindle. This structure has the following problems: because the sun gear needs to be provided with an inner hole, the sun gear is large in size and large in number of teeth, and the transmission ratio of the planetary reduction mechanism is limited. In addition, because the size of the sun gear is large, the modulus of the gear is limited, the bearing capacity is limited, and the requirements of the electric bicycle on high transmission ratio, high bearing capacity and small volume cannot be met.

Second kind: the main shaft is of a left half shaft structure and a right half shaft structure which are not connected with each other: in order to overcome the first disadvantage of completely penetrating the main shaft, the main shaft is chopped by the structure, and left and right half shafts which are disconnected and not connected are formed. Therefore, the motor output shaft and the sun gear are not provided with inner holes, the number of teeth of the sun gear can be reduced as much as possible, and the requirement of the transmission ratio is met. This structure has the following problems: because the main shaft is disconnected into the left half shaft and the right half shaft, the gear box and the whole driving unit are required to be aligned, positioned and supported by the shell, the requirement on the installation precision is too high, and the reliability of the whole structure is lower.

Therefore, how to provide a high-transmission-ratio, high-bearing capacity, small-size, high-reliability and easy-to-install-assembly hub motor gear reduction mechanism is a problem to be solved urgently at present.

Disclosure of Invention

Aiming at the defects existing in the prior art, the utility model provides a gear reduction mechanism and a gear reduction method for an in-wheel motor, which can effectively solve the problems.

The technical scheme adopted by the utility model is as follows:

the utility model also provides a hub motor gear reduction mechanism, comprising: the device comprises a main shaft (1), an eccentric sleeve (2), a bearing (3), a duplex planetary gear (4), an output gear ring (5), an external fixed gear (6) and a one-way clutch (7);

the main shaft (1) passes through the central hole of the eccentric sleeve (2) and the inner ring of the isolator (7); the eccentric sleeve (2) is sleeved on the outer surface of the main shaft (1) in a hollow mode, and can rotate freely relative to the main shaft (1); the central hole of the eccentric sleeve (2) is coaxial with the main shaft (1), and the rotation axis of the eccentric sleeve (2) is coincident with the axis of the main shaft (1); an inner ring of the isolator (7) is fixed with the outer surface of the main shaft (1), and an outer ring of the isolator (7) can rotate in one direction relative to the main shaft (1);

the axis of the outer cylindrical surface of the eccentric sleeve (2) and the rotating axis of the eccentric sleeve are provided with an eccentric distance, and the outer cylindrical surface of the eccentric sleeve (2) is sleeved with the bearing (3); the outer ring of the isolator (7) is sleeved with the outer fixed gear (6) fixedly;

the double planetary gear (4) comprises a planetary gear shell (4-1), wherein one end outer surface of the planetary gear shell (4-1) is provided with a planetary external gear (4-2), the other end inner cavity is provided with a planetary internal gear (4-3), and the inner cavity of the planetary external gear (4-2) is sleeved outside the bearing (3) and is fixed with the outer surface of the bearing (3); the planetary internal gear (4-3) is sleeved outside the outer fixed gear (6) and meshed with the outer fixed gear (6) in involute small tooth difference mode to form a first gear pair; the outer part of the planetary external gear (4-2) is sleeved with the output gear ring (5) and meshed with the output gear ring (5) in involute small tooth difference mode to form a second gear pair;

when the hub motor is driven by power, the eccentric sleeve (2) is a power input part, and the output gear ring (5) is fixedly connected with the hub (8) and is a power output part.

Preferably, the device also comprises a balance body (9); the eccentric sleeve (2) is fixed with the balance body (9).

Preferably, the main shaft (1) is a rear wheel main shaft of an electric bicycle; the main shaft (1) is fixedly connected with the electric bicycle frame.

Preferably, the motor also comprises a motor stator (10) and a motor outer rotor (11);

the motor stator (10) is fixedly connected with the main shaft (1); the motor outer rotor (11) is sleeved outside the main shaft (1) through a rotor bearing (12) and can rotate freely relative to the main shaft (1); the motor outer rotor (11) is fixedly connected with the eccentric sleeve (2).

The hub motor gear reduction mechanism and the method provided by the utility model have the following advantages:

the wheel hub motor gear speed reducing mechanism and the method provided by the utility model are high in transmission ratio, high in bearing capacity, small in size, high in reliability and easy to install and assemble.

Drawings

FIG. 1 is a front view of a gear reduction mechanism for an in-wheel motor provided by the present utility model;

FIG. 2 is a cross-sectional view taken along line D-D of FIG. 1;

FIG. 3 is a cross-sectional view of the gear reduction mechanism for an in-wheel motor provided by the present utility model for use in electrically assisted bicycles;

fig. 4 is a perspective view of a duplex planetary gear provided by the utility model;

FIG. 5 is a perspective view of the gear reduction mechanism of the in-wheel motor provided by the utility model at an angle;

fig. 6 is a perspective view of the gear reduction mechanism of the in-wheel motor provided by the utility model at another angle.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects solved by the utility model more clear, the utility model is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

The utility model provides a wheel hub motor gear reduction mechanism, which is a gear reduction mechanism for an electric power assisted bicycle wheel hub motor, and creatively uses a duplex planetary gear for the electric power assisted bicycle gear reduction mechanism. In addition, the main shaft is a main shaft which is communicated left and right, so that the reliability is high, the assembly is easy, and the bearing capacity is high; through the design of the structural space, the size and the volume of the gear box can be effectively reduced; and also has the characteristic of high transmission ratio.

The present utility model provides a gear reduction mechanism of an in-wheel motor, referring to fig. 1, 2 and 3, comprising: the device comprises a main shaft 1, an eccentric sleeve 2, a bearing 3, a duplex planetary gear 4, an output gear ring 5, an external fixed gear 6 and a isolator 7;

the main shaft 1 passes through the central hole of the eccentric sleeve 2 and the inner ring of the isolator 7; wherein, the center hole of the eccentric sleeve 2 is sleeved on the outer surface of the main shaft 1, and the eccentric sleeve 2 can rotate freely relative to the main shaft 1; the central hole of the eccentric sleeve 2 is coaxial with the main shaft 1, and the rotation axis of the eccentric sleeve 2 is coincident with the axis of the main shaft 1; the inner ring of the isolator 7 is fixed with the outer surface of the main shaft 1, and the outer ring of the isolator 7 can rotate in one direction relative to the main shaft 1;

that is, the outer race of the one-way clutch 7 can rotate in only one direction relative to the main shaft 1, and cannot rotate in the other direction.

The axis of the outer cylindrical surface of the eccentric sleeve 2 has an eccentric distance with the rotation axis of the eccentric sleeve; the outer cylindrical surface of the eccentric sleeve 2 is sleeved with a mounting bearing 3; the bearing 3 may be a needle bearing or other type of bearing, and the present utility model is not limited thereto. An outer ring of the isolator 7 is sleeved with an outer fixed gear 6; the eccentric sleeve 2 can be further fixed with the balance body 9 to meet the balance requirement.

As shown in fig. 4, which is a structure diagram of the duplex planetary gear 4, the duplex planetary gear 4 comprises a planetary gear housing 4-1, wherein one end outer surface of the planetary gear housing 4-1 is provided with a planetary external gear 4-2, the other end inner cavity is provided with a planetary internal gear 4-3, and the inner cavity of the planetary external gear 4-2 is sleeved outside the bearing 3 and is fixed with the outer surface of the bearing 3; the planetary internal gear 4-3 is sleeved outside the external fixed gear 6 and meshed with the external fixed gear 6 in involute small tooth difference mode to form a first gear pair; as shown in fig. 5, a specific structural form of the first gear pair can be seen. The outer part of the planetary external gear 4-2 is sleeved with an output gear ring 5, and is meshed with the output gear ring 5 in involute small tooth difference, so as to form a second gear pair; as shown in fig. 6, a specific structural form of the second gear pair can be seen.

When the hub motor is driven by power, the eccentric sleeve 2 is a power input part, and the output gear ring 5 is fixedly connected with the hub 8 and is a power output part.

As a specific use scene, the main shaft 1 is a main shaft of a rear wheel of an electric bicycle; the main shaft 1 is fixedly connected with the electric booster bicycle frame.

In concrete implementation, the motor comprises a motor stator 10 and a motor outer rotor 11 as power sources, and the motor stator 10 is fixedly connected with the main shaft 1; the motor outer rotor 11 is sleeved outside the main shaft 1 through a rotor bearing 12 and can rotate freely relative to the main shaft 1; the motor outer rotor 11 is fixedly connected with the eccentric sleeve 2.

The utility model provides a speed reduction method of a hub motor gear speed reduction mechanism, which comprises the following steps:

step 1, electric power bicycle advancing state in electric driving state:

step 1.1, when a motor stator 10 passes current, a driving motor outer rotor 11 rotates around a main shaft 1 in a driving direction;

step 1.2, when the motor outer rotor 11 rotates, the eccentric sleeve (2) is driven to rotate around the main shaft (1), and the axis of the outer cylindrical surface of the eccentric sleeve 2 eccentrically rotates around the main shaft (1);

step 1.3, when the outer cylindrical surface of the eccentric sleeve 2 eccentrically rotates around the main shaft 1, the double planetary gear 4 is driven to revolve; in addition, at this time, under the limiting action of the external fixed gear 6, the duplex planetary gear 4 performs revolution rotation on one hand, and only performs autorotation under the constraint condition of the external fixed gear 6 on the other hand;

when the double planetary gear 4 revolves under the drive of the eccentric sleeve 2, on one hand, the double planetary gear 4 is meshed with the output gear ring 5, so that the output gear ring 5 is driven to rotate; when the output gear ring 5 rotates, the hub 8 is driven to rotate, so that power output is realized; on the other hand, while the double planetary gear 4 revolves and rotates, the planetary inner gear 4-3 of the double planetary gear 4 rotates, at this time, the rotation of the planetary inner gear 4-3 applies a first direction torsion force to the external fixed gear 6, and since the external fixed gear 6 and the outer ring of the one-way clutch 7 are fixed, and further since the outer ring of the one-way clutch 7 cannot rotate in the first direction relative to the main shaft 1, the external fixed gear 6 cannot rotate in the first direction, and thus the autorotation rotation of the planetary inner gear 4 in the first direction is restrained;

the outer ring of the isolator 7 and the external fixed gear 6 cannot rotate in the first direction, so that the isolator further acts on the duplex planet wheel 4 to limit the duplex planet wheel 4, and the duplex planet wheel 4 can perform revolution rotation on one hand and can only perform autorotation under the constraint condition of the external fixed gear 6 on the other hand;

the planetary internal gear 4-3 applies torsion in the first direction to the external fixed gear 6, the external fixed gear 6 restrains the planetary internal gear 4-3 from rotating in the first direction, and gives the planetary internal gear 4-3 a reaction torsion, and the output gear ring 5 is driven to rotate forwards under the combined action of the reaction torsion and the eccentric sleeve driving torsion, so that power output is formed.

Step 2, electric assist bicycle forward running state at the time of non-electric driving, for example, forward running state depending on inertial force:

step 2.1, the motor stator 10 does not pass current, and therefore, the motor outer rotor 11 is not driven to rotate around the spindle 1; thus, the eccentric sleeve 2 does not rotate;

when the electric booster bicycle is driven to move forward by inertial force, the hub 8 rotates, and then the output gear ring 5 is driven to rotate;

when the output gear ring 5 rotates, the double planetary gear 4 meshed with the output gear ring is driven to rotate, and at the moment, the eccentric sleeve 2 does not rotate, and the double planetary gear 4 only rotates in a autorotation mode and does not revolve;

step 2.2, when the duplex planetary gear 4 rotates in a self-rotation way, the planetary internal gear 4-3 of the duplex planetary gear 4 rotates, and at the moment, the rotation of the planetary internal gear 4-3 applies torsion in a second direction to the external fixed gear 6, and the torsion in the second direction is opposite to the torsion in the first direction; the torsion in the second direction causes the outer ring of the isolator 7 fixedly connected with the outer fixed gear 6 to rotate; the outer race of the isolator 7 is free to rotate relative to the inner race in the second direction, unconstrained.

Therefore, when the hub 8 rotates and drives the duplex planetary gear 4 to rotate in a self-rotation way, and when force is transmitted to the isolator 7, the outer ring of the isolator 7 rotates along with the rotation of the hub, at the moment, the isolator 7 is free to overrun and rotate to block further transmission of force, so that a reverse driving motor is avoided when the electric bicycle slides forwards, and sliding resistance is reduced.

The utility model provides a hub motor gear reduction mechanism and a method thereof, which have the following characteristics:

1) The transmission ratio far higher than that of the traditional planetary transmission mechanism is obtained by a small volume size, so that the installation space is effectively saved, and the transmission ratio is improved;

2) Because the two gear pairs are involute few-tooth-difference transmission structures, the tooth number difference between the duplex planet gears and the output gear ring is very small and is usually only 1 to 3 teeth, the radial dimension of the duplex planet gears is large enough, and the center of the duplex planet gears still has enough space to allow a main shaft which is penetrated left and right to pass through although the duplex planet gears run eccentrically. Therefore, the contradiction between the transmission ratio and the through shaft is effectively solved.

The main shaft adopts a through shaft structure and penetrates through the whole driving unit, and the stability and the reliability of the device are improved due to the fact that the main shaft is not of a two-section structure;

3) Since the required gear ratio can be easily obtained, it is not necessary to obtain the necessary gear ratio in a way that increases the number of teeth (the number of teeth of the ring gear of the conventional planetary mechanism of the in-wheel motor tends to be more than 100 teeth). The utility model can greatly reduce the tooth number of the gear ring and each gear. (the number of teeth of the ring gear of this example is only 42). Thus, the modulus of the gear can be greatly increased in the same space, while still controlling the size of the gear within a desired range. Therefore, the bearing capacity of the gear mechanism can be greatly improved, and the output torque can be effectively increased under the condition of the same size.

4) The number of teeth of the gears of the gear transmission mechanism is obviously reduced, and an eccentric sleeve, an external fixed gear and a one-way device are arranged in the space between the main shaft and the duplex planetary gear, so that the eccentric sleeve, the external fixed gear and the one-way device are assembled in the duplex planetary gear, and the radial size and the axial length of the device are effectively reduced;

5) According to the utility model, the double planetary gear is used for the gear reduction mechanism of the electric bicycle, and the electric bicycle forward function in an electric driving state can be realized, the electric bicycle forward function in a non-electric driving state can be realized, and the use requirement of the electric bicycle is met through the cooperation of the double planetary gear, the eccentric sleeve, the output gear ring, the external fixed gear and the isolator. The isolator is arranged in the outer fixed gear, so that the installation space can be further saved.

The foregoing is merely a preferred embodiment of the present utility model and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present utility model, which is also intended to be covered by the present utility model.

Claims (4)

1. A wheel hub motor gear reduction mechanism, comprising: the device comprises a main shaft (1), an eccentric sleeve (2), a bearing (3), a duplex planetary gear (4), an output gear ring (5), an external fixed gear (6) and a one-way clutch (7);

the main shaft (1) passes through the central hole of the eccentric sleeve (2) and the inner ring of the isolator (7); the eccentric sleeve (2) is sleeved on the outer surface of the main shaft (1) in a hollow mode, and can rotate freely relative to the main shaft (1); the central hole of the eccentric sleeve (2) is coaxial with the main shaft (1), and the rotation axis of the eccentric sleeve (2) is coincident with the axis of the main shaft (1); an inner ring of the isolator (7) is fixed with the outer surface of the main shaft (1), and an outer ring of the isolator (7) can rotate in one direction relative to the main shaft (1);

the axis of the outer cylindrical surface of the eccentric sleeve (2) and the rotating axis of the eccentric sleeve are provided with an eccentric distance, and the outer cylindrical surface of the eccentric sleeve (2) is sleeved with the bearing (3); the outer ring of the isolator (7) is sleeved with the outer fixed gear (6) fixedly;

the double planetary gear (4) comprises a planetary gear shell (4-1), wherein one end outer surface of the planetary gear shell (4-1) is provided with a planetary external gear (4-2), the other end inner cavity is provided with a planetary internal gear (4-3), and the inner cavity of the planetary external gear (4-2) is sleeved outside the bearing (3) and is fixed with the outer surface of the bearing (3); the planetary internal gear (4-3) is sleeved outside the outer fixed gear (6) and meshed with the outer fixed gear (6) in involute small tooth difference mode to form a first gear pair; the outer part of the planetary external gear (4-2) is sleeved with the output gear ring (5) and meshed with the output gear ring (5) in involute small tooth difference mode to form a second gear pair;

when the hub motor is driven by power, the eccentric sleeve (2) is a power input part, and the output gear ring (5) is fixedly connected with the hub (8) and is a power output part.

2. A wheel hub motor gear reduction mechanism according to claim 1, further comprising a balancing body (9); the eccentric sleeve (2) is fixed with the balance body (9).

3. A hub motor gear reduction mechanism according to claim 1, characterized in that the main shaft (1) is a rear wheel main shaft of an electric bicycle; the main shaft (1) is fixedly connected with the electric bicycle frame.

4. A hub motor gear reduction mechanism according to claim 1, further comprising a motor stator (10) and a motor outer rotor (11);

the motor stator (10) is fixedly connected with the main shaft (1); the motor outer rotor (11) is sleeved outside the main shaft (1) through a rotor bearing (12) and can rotate freely relative to the main shaft (1); the motor outer rotor (11) is fixedly connected with the eccentric sleeve (2).

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