KR20240053879A - Seal for In-wheel Motor and Sealing Device for In-wheel Motor Including The Seal - Google Patents

Abstract

The present invention relates to a seal for blocking moisture and foreign substances flowing into the space between the stator and rotor of an in-wheel motor and a sealing device including the same. The lips provided in the seal according to the present invention are located in the axial direction of the slinger and the stator. Since it is only in contact with the seal, not only can the durability of the seal be maintained even in a very high peripheral speed usage environment, but also the friction between the lips and the slinger is reduced by maintaining constant contact between the slinger and the lips even when eccentricity occurs due to the operation of the in-wheel motor. This has the effect of reducing the torque loss of the in-wheel motor.

Description

Seal for in-wheel motor and sealing device for in-wheel motor including the same {Seal for In-wheel Motor and Sealing Device for In-wheel Motor Including The Seal}

The present invention relates to a seal for an in-wheel motor and a sealing device for an in-wheel motor including the same for blocking foreign substances such as moisture and dust from entering the space between the stator and the rotor of the in-wheel motor.

The content described below only provides background information related to the present invention and does not constitute prior art.

A device that transmits driving force, such as a vehicle's transmission, axle, hub bearing, etc., includes a case that constitutes the device and a shaft that passes through the outside and inside of the case and transmits the driving force. (shaft) is provided, and a seal and sealing device are provided to prevent foreign substances such as external dust and dirt from penetrating into the gap between the case and the shaft.

The seal must form a constant contact surface with the shaft surface not only when the shaft is stationary but also when it rotates at high speed to block external foreign substances.

Therefore, if the seal and the shaft do not form a sufficient contact surface and contact pressure, the penetration of external foreign substances cannot be prevented, and if the seal and the shaft have an excessive contact surface and contact pressure, the driving force of the shaft may be lost due to friction between the shaft and the seal. Additionally, seals may become damaged or worn. Therefore, the seal must be designed to contact the surface of the shaft with an appropriate pressure, that is, a pressure that can minimize friction with the shaft while preventing penetration of foreign substances.

Meanwhile, instead of vehicles using fossil fuels such as gasoline and diesel, electric vehicles that drive motors using electrical energy stored in batteries are being developed.

In-wheel motors are a technology used in vehicles that use electricity as a power source, such as the electric vehicles above. Unlike the method in gasoline or diesel vehicles where the wheels are driven to rotate by power transmission through the engine-transmission-drive shaft, the wheel rim Power is transmitted directly to the wheels by a motor placed inside. Therefore, when applying an in-wheel motor, driving and power transmission devices such as engines, transmissions, and differential gears can be omitted, which reduces the weight of the vehicle and has the advantage of reducing energy loss in the power transmission process.

There are two main driving methods used for in-wheel motors: the outer ring rotation method and the inner ring rotation method.

Figure 1 shows an exploded perspective view of a wheel structure on which an outer ring rotation type in-wheel motor is mounted, and Figure 2 shows a wheel structure on which an outer ring rotation type in-wheel motor is mounted.

As shown in Figures 1 and 2, the outer ring rotation type in-wheel motor has a structure in which the inner motor stator 170 and the outer rotor 180 are arranged to face each other, and the motor stator 170 ) is wound with a coil 171, and the rotor 180 is provided with a permanent magnet 181. The motor stator 170 of the in-wheel motor is fixed to the knuckle 30 via a stator bracket 80. Since the knuckle 30 is fixed to the vehicle body, the motor stator 170 of the in-wheel motor is also fixed to the vehicle body. Meanwhile, the rotor 180 of the in-wheel motor is fixed to the wheel 140 via the rotor bracket 130, so when the in-wheel motor operates and the rotor 180 rotates with respect to the motor stator 170, the wheel 140 and The wheel 141 also rotates together.

In the case of the in-wheel motor shown in FIG. 2, there is no means to prevent foreign substances from entering the in-wheel motor, and foreign substances introduced from the outside have a fatal effect on the operation of the in-wheel motor operated by electricity. do. Therefore, a means to prevent the penetration of external foreign substances is essential.

In order to prevent external foreign substances from penetrating into the space between the bracket 130 and the stator bracket 80, the gap between the motor stator 170 and the outer rotor 180 and the inner ring 50 and outer ring 70 of the wheel bearing are ) It is necessary to close the gap between.

In the above-mentioned in-wheel motor, the gap between the inner ring 50 and the outer ring 70 of the wheel bearing has no problem using normal bearing seals and sealing devices.

However, in order to close the gap between the motor stator 170 and the outer rotor 180, a different concept of seal and sealing device is required. In order to close the gap between the motor stator 170 and the outer rotor 180, a sealing device having a much larger diameter (R2) than the diameter (R1) of the bearing sealing device as shown in FIG. 2 is required. (R2 is about 6 times more than R1)

In the case of a sealing device with a diameter of R2, it has a circumferential speed (v=rθ/t, r; radius, θ; rotation angle, t; time) that is about 6 times more than that of a sealing device with a diameter of R1, so it takes the same amount of time. Even in operation, a seal with a diameter of R2 is exposed to much greater friction than a seal with a diameter of R1. In addition, when the in-wheel motor is driven due to the load of the vehicle, the seal with a diameter of R2 generates a much larger eccentricity than the bearing seal with a diameter of R1, resulting in the problem of not providing uniform friction.

That is, the existing sealing device, such as the sealing device having a diameter of R1, can be applied when the diameter is 100 mm or less and the eccentricity is 0.2 mm or less, but as shown in FIG. 2, the diameter is 300 mm or more and the eccentricity is 1.0 mm or less. It cannot be applied in cases above (i.e. sealing devices with a diameter of R2).

In U.S. Patent Publication US 2005/0247469 A1 (published on November 10, 2005), first and second annular dust boots (61, 62), but the first and second annular dust boots 61 and 62 have a disadvantage in that their structures are complex and the reduction in motor output due to the frictional force of the dust boots is not taken into consideration.

Therefore, in an in-wheel motor, a new concept of a seal and a sealing device including the same that can block the gap between the stator and the rotor to prevent foreign substances from penetrating are required.

US Patent Publication US 2005/0247469 A1 (published on November 10, 2005) Registered Patent Publication No. 10-2270469 (announced on June 28, 2021)

The present invention relates to a seal for blocking moisture and foreign substances flowing into the space between the stator and rotor of an in-wheel motor, and a sealing device including the same. In order to close the gap between the stator and rotor of an in-wheel motor, the torque output of the in-wheel motor is reduced by reducing the durability that can be used at very high circumferential speeds and the friction force caused by eccentricity that occurs as the rotor rotates when driving the in-wheel motor. A seal and a sealing device including the same are required.

The seal for an in-wheel motor according to the present invention is applied between the rotor and the stator of the in-wheel motor, and the seal includes a plurality of lips forming a contact surface with the slinger, and the plurality of lips are in the same direction as the rotation axis of the in-wheel motor. It is configured to form only a contact surface. Therefore, compared to the case where the lips of the seal form a contact surface in a direction perpendicular to the rotation axis ( It can also have excellent durability.

The seal according to the invention may be composed of a rubber material.

The seal according to the present invention includes a seal body, wherein the seal body includes a first part formed close to the axis, a third part parallel to the first part and stepped at a higher position than the first part, and the third part formed to be stepped at a higher position than the first part. A second part that obliquely connects the first part and the third part, the first and second lips arranged in the first part, the connection between the first part and the third part, or the third lip arranged in the third part. may include.

The first, second, and third lips of the seal according to the present invention form a concentric circle from the axis of the seal body, and the first, second, and third lips may all be arranged to be inclined outward about the axis.

The seal according to the invention can be formed integrally with the dust cover.

A sealing device for an in-wheel motor according to the present invention includes a plurality of lips forming a contact surface with a slinger, wherein the plurality of lips are configured to form only a contact surface in the same direction as the rotation axis of the in-wheel motor; a dust cover formed integrally with the seal; and a slinger forming a contact surface with the plurality of lips.

Since the contact surface of the first, second, and third ribs with the slinger is formed only in the axis ( It can be durable.

The dust cover according to the present invention may be fixed to the stator of the in-wheel motor, and the slinger may be fixed to the rotor of the in-wheel motor.

The seal according to the present invention includes a seal body, wherein the seal body includes a first part formed close to the axis, a third part parallel to the first part and formed to be stepped at a higher position than the first part, A second part obliquely connecting the first part and the third part, first and second lips disposed in the first part, and a third lip disposed at the connection portion of the first part and the third part or the third part. Includes; The dust cover includes a first part, a third part parallel to the first part and stepped at a position higher than the first part, a second part inclinedly connecting the first part and the third part, and fixed to a stator. Includes a fixture; The slinger has a first part that contacts the first and second lips of the seal body, a second part that is fixed to the inside of the rotor, and a third part that is seated on the top of the rotor and touches the third lip of the dust seal body. It may include protrusions protruding toward the dust cover from ends of the first and third parts.

The first, second, and third lips according to the present invention form a concentric circle from the axis of the seal body, and the first, second, and third lips may be arranged to be inclined outward about the axis.

The present invention relates to a seal for blocking moisture and foreign substances flowing into the space between the stator and rotor of an in-wheel motor and a sealing device including the same, wherein the lips provided on the seal contact only the axial direction of the slinger and the stator. Therefore, not only can the durability of the seal be maintained even in a very high peripheral speed usage environment, but also the slinger and the lips maintain constant contact even when eccentricity occurs due to the rotation of the rotor when driving the in-wheel motor, thereby reducing friction between the lips and the slinger. This has the effect of reducing the torque loss of the in-wheel motor.

Figure 1 shows an exploded perspective view of a wheel structure on which an in-wheel motor of the outer ring rotation type is mounted.
Figure 2 shows a side cross-sectional view showing a wheel structure on which an outer ring rotation type in-wheel motor is mounted.
Figure 3 shows a cross-sectional and perspective view of a seal according to the invention.
Figure 4 shows an embodiment in which a sealing device including a seal, dust cover and slinger according to the present invention is disposed on the stator and rotor of an in-wheel motor.

The terminology used herein is for describing embodiments and is not intended to limit the invention. As used herein, singular forms also include plural forms, unless specifically stated otherwise in the context. As used in the specification, “comprises” does not exclude the presence or addition of one or more other components in addition to the mentioned components.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used with meanings commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless clearly specifically defined.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein.

Hereinafter, the present invention will be described in more detail.

Figure 3 shows a cross-section and a perspective view of the seal 200 and the dust cover 400 in a combined state according to an embodiment of the present invention.

The seal 200 includes a seal body 210, which includes first, second, and third lips (220, 230, 240) and first, second, and third parts (250, 260, 270). ) includes. The three lips 220, 230, and 240 form a concentric circle from the axis ), and the third lip 240 is parallel to the first part 250 and is formed to be stepped at a higher position than the first part 250. It is disposed at the connection part 280 of the second part 260 that connects the three parts 270 in an inclined manner. The first, second, and third ribs 220, 230, and 240 are all arranged to be inclined outward about the axis This prevents foreign substances such as moisture and dust from entering. The length and inclination angle of the lips can be varied in consideration of the distance between the stator and the rotor, the slinger and the friction force, etc.

When the contact surface with the slinger is formed only in a direction parallel to the axis (X), such as the first, second, and third ribs (220, 230, and 240) described above, the lips have a contact surface in a direction perpendicular to the axis (X). Compared to other cases, even when eccentricity occurs, it has a uniform friction force with the slinger (not shown), so not only can the efficiency of the in-wheel motor be increased, but it can also have excellent durability even at high circumferential speeds.

The seal 200 according to the present invention may be made of an elastic material containing rubber.

In Figure 3, the third lip 240 is shown as being disposed at the connection portion 280 of the second part 260 and the third part 270 of the seal body 210, but the third lip 240 is located in the third part 240. It may also be placed at (270).

3 shows that the seal 200 is formed integrally with the dust cover 400, but the seal 200 and the dust cover 400 may be separately constructed and assembled as one, preferably a seal made of rubber ( 200) and the dusk cover 400 may be integrally molded in a mold.

Figure 4 shows an example of a state in which a sealing device including a dust cover 400 and a slinger 300 including a seal 200 according to the present invention is mounted on an in-wheel motor.

As shown in FIG. 4, the dust cover 400 is fixed to the stator (S) of the in-wheel motor, and the slinger 300 is fixed to the rotor (R) of the in-wheel motor. There is no limitation to the means for fixing the dust cover 400 and the slinger 300, but an interference fit method as shown in FIG. 4 may be used, or they may be fixed using fastening means such as bolts.

There is no limitation on the shape of the dust cover 400, but preferably a corresponding shape is provided to support the first, second, and third parts 250, 260, and 270 of the seal body 210 as shown in FIG. 4. It is desirable to have a shape.

That is, the dust cover 400 has a shape corresponding to the first, second, and third parts 250, 260, and 270 of the seal body 210, and is parallel to the first part 450. It includes a third part 470 formed to be stepped at a higher position than the first part 450 and a second part 460 inclined to connect the first part 450 and the third part 470, and the stator It includes a fixing part 410 on the side of (S).

As shown in FIG. 4, the first and second parts 450 and 460 of the dust cover 400 are disposed between the stator (S) and the rotor (R), and the third part 470 of the dust cover 400 ) is placed on the upper part of the rotor (R).

In addition, there is no limitation on the shape of the slinger 300, but preferably the first part 310, which is in contact with the first and second lips 220 and 230 of the seal body 210, as shown in FIG. It includes a second part 320 fixed to the inside of the electron (R), and a third part 330 that is seated on the upper part of the rotor (R) and is in contact with the third lip 240 of the seal body 210. , It further includes protrusions 340 and 350 protruding from ends of the first part 310 and the third part 330 toward the dust cover 400.

The protrusions 340 and 350 serve to reduce the gap between the dust cover 200 and the slinger 300, thereby reducing the space where external moisture and foreign substances enter.

Various maze structures are applied to the slinger 300 to prevent the movement of foreign substances flowing along the surface of the slinger 300.

Grease is applied to the space between the first, second, and third lips (220, 230, 240) and the slinger 300 and between the first lip (220) and the protrusion 340 to reduce friction between the lips and the slinger. You can do it.

As described above, the third lip 240 provided on the seal body 210 according to the present invention is in contact with the third part 330 of the slinger 300 to prevent external foreign substances from entering the dust cover 400 and the slinger. (300), and the second and first lips (230, 220) provided on the seal body (210) prevent foreign substances from entering the space between the stator (S) and the rotor (R), that is, This further prevents it from flowing into the inside of the in-wheel motor.

The first, second, and third ribs (220, 230, 240) are oriented parallel to the axis (X) of the first, second, and third parts (310, 320, 330) of the slinger (300) and the stator (S) Since there is only contact with the in-wheel motor, constant contact between the slinger 300 and the first, second, and third ribs 220, 230, and 240 can be maintained even when eccentricity occurs due to the rotation of the rotor (R) when driving the in-wheel motor. By reducing the friction between the in-wheel motor and the slinger, not only can the torque loss of the in-wheel motor be reduced, but the durability of the seal can be improved despite high peripheral speeds.

In other words, if there is a surface between the seal and the slinger that contacts in a direction perpendicular to the axis (If a lip contacting the second part 320 is provided) When the in-wheel motor is driven, eccentricity occurs due to the rotation of the rotor (R), and accordingly, the axis (X) perpendicular to the axis (X) of the stator (S) Excessive friction occurs on surfaces that contact each other, increasing the torque loss of the in-wheel motor, which not only reduces the efficiency of the in-wheel motor but also reduces the durability of the seal itself.

Although the above embodiments describe the case where the sealing device according to the present invention is applied to an in-wheel motor of the outer ring rotation type, the sealing device can also be applied to an in-wheel motor of the inner ring rotation type.

In addition, FIG. 4 shows a case where the dust cover and slinger are exposed to the inside of the in-wheel motor (i.e., the upper part of FIG. 4) (i.e., when the inner surface of the vehicle wheel on which the in-wheel motor is mounted is upper), but the dust cover And the slinger may be disposed outside the in-wheel motor (i.e., at the bottom of FIG. 4).

In the above embodiment, an example in which the seal body is provided with three lips is described, but the number and arrangement positions of the lips may be changed in various ways as needed. Additionally, the seal according to the present invention may be made of an elastic material such as rubber, and the dust cover and slinger may be made of a rigid body and a metal material.

100; seal
110; seal body
120; 1st grain
130; 2nd lip
140; 3rd grain
150; Part 1
160; Part 2
170; Part 3
180; connection
200; dust cover
250; Part 1
260; Part 2
270; Part 3
300; slinger
310; Part 1
320; Part 2
330; Part 3
340, 350; projection part
400; dust cover
410; fixed part
450; Part 1
460; Part 2
470; Part 3
R; rotor
S; stator
X; axis

Claims (9)

A seal applied between the rotor and the stator of an in-wheel motor. The seal includes a plurality of lips that form a contact surface with the slinger, and the plurality of lips are configured to form only a contact surface in the same direction as the rotation axis of the in-wheel motor. A seal for in-wheel motors.
The seal for an in-wheel motor according to claim 1, wherein the seal is made of a rubber material.
The method of claim 1 or 2, wherein the seal includes a seal body and lips, the seal body comprising: a first portion formed proximate to the axis; a third part parallel to the first part and formed to be stepped at a higher position than the first part; a second part connecting the first part and the third part in an inclined manner, wherein the lips include first and second lips disposed on the first part; A seal for an in-wheel motor, comprising a connection portion between the first part and the third part, or a third lip disposed on the third part.
The in-wheel motor according to claim 3, wherein the first, second, and third lips form a concentric circle from the axis of the seal body, and the first, second, and third lips are all arranged to be inclined outward about the axis. Dragon seal.
The seal for an in-wheel motor according to claim 4, wherein the seal is formed integrally with the dust cover.
A sealing device applied to an in-wheel motor, wherein the sealing device includes a plurality of lips forming a contact surface with a slinger, wherein the plurality of lips are configured to form only a contact surface in the same direction as the rotation axis of the in-wheel motor; a dust cover formed integrally with the seal; and a slinger forming a contact surface with the plurality of lips.
The sealing device for an in-wheel motor according to claim 6, wherein the dust cover is fixed to the stator of the in-wheel motor, and the slinger is fixed to the rotor of the in-wheel motor.
The method according to claim 6 or 7, wherein the seal includes a seal body and lips, wherein the seal body includes a first part formed close to the axis, parallel to the first part, and formed to be stepped at a higher position than the first part. It includes a third part, a second part that obliquely connects the first part and the third part, and the ribs include first and second ribs disposed in the first part, the first part and the third part. comprising a third lip disposed at the connection portion or the third portion; The dust cover includes a first part, a third part parallel to the first part and stepped at a position higher than the first part, a second part inclinedly connecting the first part and the third part, and fixed to a stator. Includes a fixture; The slinger has a first part that contacts the first and second lips of the seal body, a second part that is fixed to the inside of the rotor, and a third part that is seated on the top of the rotor and touches the third lip of the dust seal body. and a protrusion protruding from ends of the first and third parts toward the dust cover.
The method according to claim 8, wherein the first, second, and third lips form a concentric circle from the axis of the seal body, and the first, second, and third lips are arranged to be inclined outward about the axis. Sealing device.

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