CN114688169A - Seal assembly and seal structure - Google Patents

Abstract

The present disclosure relates to a seal assembly and a seal structure. Wherein the seal assembly includes a support body including first and second diametrically opposed ends; a sealing body attached to the support body, the sealing body including: the main sealing lip wraps the first end of the support body, and is provided with an oil passing hole which is axially communicated; the secondary sealing lip wraps the second end of the support body, and the wear-resistant sealing layer is attached to one side or two sides of the primary sealing lip. The oil passing hole and the wear-resistant sealing layer are arranged at the same end of the sealing body, so that when lubrication is allowed to pass through the oil passing hole, the friction force between the sealing body and the outer ring can be reduced due to the wear-resistant sealing layer, the sealing assembly can rotate relative to the outer ring more conveniently, and the sealing assembly is prevented from running.

Description

Seal assembly and seal structure

Technical Field

The utility model relates to a sealed technical field for electric automobile especially relates to a seal assembly and seal structure.

Background

In the related art, an electric drive wheel hub (IWD) for a vehicle generally includes a first member (e.g., a shaft of an electric motor) and a second member (e.g., a gear box) which are capable of rotating relative to each other, wherein the shaft of the electric motor is capable of rotating relative to the gear box, and a contact type seal assembly is used between the shaft of the electric motor and the gear box to form a sealed space between the gear box and the seal assembly, so that lubricating oil inside the gear box can be prevented from entering the electric motor and dust and other impurities in the external environment can be prevented from entering the gear box.

However, in the conventional sealing assembly applied to the bearing or the gear box in the electric driving field, the bearing or the gear box is easy to accumulate a large amount of electric charges under the working condition, and the electric current formed by the accumulated electric charges cannot be released because the lubricating oil inside the bearing is too thin and the lubricating oil inside the gear box cannot enter the bearing until the electric charges are accumulated to cause the raceway of the bearing to generate an excessive shaft voltage. Finally, spark discharges occur due to excessive shaft voltages, which damage the bearing raceways and cause oil stains and washboard-like ridge damage on the raceways, which greatly affect the quality and life of the bearings and other drive systems such as gears and gearboxes.

Disclosure of Invention

To overcome the problems in the related art, the present disclosure provides a seal assembly and a seal structure.

According to a first aspect of embodiments of the present disclosure, there is provided a seal assembly comprising: a support body including first and second diametrically opposed ends; a sealing body attached to the support body, the sealing body including: the primary sealing lip wraps the first end of the support body, the primary sealing lip is provided with an oil passing hole which is axially communicated, and the secondary sealing lip wraps the second end of the support body; and the wear-resistant sealing layer is attached to one side or two sides of the main sealing lip.

In some embodiments, the support body further comprises first and second axially opposed sides; the wear-resistant sealing layer is annular and attached to one side, close to the first side, of the main sealing lip.

In some embodiments, the primary seal lip extends obliquely toward the second side of the support body and away from the second end such that the primary seal lip is disposed obliquely with respect to the support body.

In some embodiments, the secondary sealing lip extends toward the first side of the support body such that the secondary sealing lip is hook-shaped.

In some embodiments, the radially inner side of the secondary sealing lip is provided with one or more grooves.

In some embodiments, the oil passing holes are provided with one or more.

In some embodiments, the oil passing holes are provided in plurality, and the oil passing holes are arranged at equal intervals or at unequal intervals along the circumferential direction of the main seal lip.

In some embodiments, the support is stamped from an electrically conductive, hard material; the sealing body is made of conductive elastic material; and the wear-resistant sealing layer is made of polytetrafluoroethylene.

In some embodiments, the shape of the oil passing hole is one or a combination of a semicircular shape, a U-shape, a rectangular shape, a triangular shape and an inverted trapezoid shape.

According to a second aspect of embodiments of the present disclosure, there is provided a sealing structure comprising: the inner wall of the outer ring is provided with a first annular groove; the inner ring rotates relative to the outer ring, and a second annular groove is formed in the position, corresponding to the first annular groove, of the outer wall of the inner ring; and the seal assembly according to the first aspect, the seal assembly being disposed between the first annular groove and the second annular groove, wherein the primary seal lip of the seal body is in interference fit with the first annular groove and rotates relative to the outer ring, and the secondary seal lip of the seal body is in interference fit with the second annular groove and rotates coaxially relative to the inner ring.

The technical scheme provided by the embodiment of the disclosure can have the following beneficial effects: the oil passing hole and the wear-resistant sealing layer are arranged at the same end, far away from the motor shaft, of the sealing body, when the lubricating oil is allowed to pass through the oil passing hole, the friction force between the sealing body and the outer ring can be reduced due to the wear-resistant sealing layer, the sealing assembly can rotate relative to the outer ring conveniently, and the sealing assembly is prevented from running.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure.

FIG. 1 is a schematic cross-sectional view of a seal assembly according to the related art;

FIG. 2 is a cross-sectional schematic view of a seal assembly shown in accordance with an exemplary embodiment;

FIG. 3 is a partial perspective view of a seal assembly shown in accordance with an exemplary embodiment.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the exemplary embodiments below are not intended to represent all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

The overall shape of the seal assembly of the present disclosure is annular. Unless otherwise specified, "axial," "radial," and "circumferential" as used in the following detailed description refer to the axial, radial, and circumferential directions of the seal assembly, respectively. In the following embodiments, the axially outer side is the right side in the drawings, and the axially inner side is the left side in the drawings; the radially outer side is the upper side in the drawings, and the radially inner side is the lower side in the drawings.

The present disclosure may be applied to an electric vehicle (may also be referred to as a new energy vehicle) having an IWD system. The latest IWD system consists of three parts: a motor system, a gearbox system and a brake system. The motor system is used to drive the entire wheel, the gearbox system is used to reduce the speed of the motor system and to transfer the low speed to the axle, and the brake system is used to stop the wheel.

In the related art, for the entire IWD system, it is necessary to install a ball bearing 200 having lubricating oil between the motor side and the gear box side. As shown in fig. 1, a ball bearing 200 (e.g., a deep groove ball bearing) includes an outer ring 40, an inner ring 50, and balls 60 and lubricating oil (also called grease or oil film) between the inner ring 50 and the outer ring 40. However, for an electric vehicle such as one having an IWD system, the ball bearing 200 always has a problem of electric corrosion.

Because the oil film of the lubricating oil between the raceway and the balls 60 is very thin, the ball bearing 200 cannot remove the electric charges generated between the inner ring 50 or the outer ring 40 in time, the electric charges are not conducted between the inner ring 50 and the outer ring 40 until the electric charges are accumulated to cause the voltage to become very large, the large current causes the lubricating grease to be burnt and zoomed, and the zoomed lubricating oil causes the deep groove dent and the washboard-shaped bulge to appear on the raceway due to the overhigh voltage. This will greatly affect the quality of the bearing and shorten the service life of the bearing. Therefore, an electrically conductive seal is required to protect the bearing or shaft.

In addition, for the IWD system, the ball bearing 200 with lubricant is mounted on the motor shaft, the motor shaft rotates at a very high speed, the lubricant in the gear box tends to leave the motor shaft due to the centrifugal force of the motor shaft, and as shown in fig. 1, the seal assembly 100 makes it difficult for the lubricant in the gear box (located at the right side of the ball bearing 200 in fig. 1) to enter the inside of the ball bearing 200, and the ball bearing 200 may generate the phenomena of indentation or washboard-like bulging of the raceway caused by the fact that the above-mentioned charges cannot be conducted out of the electric current in time due to lack of lubrication.

To solve the above technical problem, the present disclosure provides a sealing assembly 100, and the sealing assembly 100 is applied between any two coaxial relatively-rotating parts in an electric drive hub. In the embodiment of the present disclosure, the sealing assembly 100 is applied between the inner ring 50 and the outer ring 40 of the ball bearing 200 between the motor system and the gear box system, and the ball bearing 200 may be a deep groove ball bearing or the like, which is not particularly limited herein. The following description will be given by taking the application to a deep groove ball bearing as an example.

As shown in fig. 2, the seal assembly 100 includes a support body 10, a seal body 20, and a wear seal layer 30.

The support body 10 comprises, in radial direction, opposite first 11 (radially outer side of the support body 10) and second 12 (radially inner side of the support body 10) ends. The support body 10 extends in a radial direction without being bent, and the support body 10 has an annular plate-shaped structure. The support body 10 comprises, in the axial direction, a first 13 (axially inner side of the support body 10) and a second 14 (axially outer side of the support body 10) opposite side.

In some embodiments, the support body 10 is stamped from an electrically conductive, hard material; for example, the support body 10 may be directly formed from a metal material through a stamping process, and the support body 10 may serve as a support and a conductive function.

The sealing body 20 is attached to the supporting body 10, the sealing body 20 covering the first end 11 and the second end 12 of the supporting body 10, as well as covering the radial outside and the radial inside of the first side 13 of the supporting body 10, and covering the entirety of the second side 14.

The sealing body 20 is made of an electrically conductive elastic material; the sealing body 20 is made of, for example, conductive rubber. The sealing body 20 may be integrally attached to the above-described surface of the supporting body 10 of the sealing body 20 by a vulcanization process. So, seal 20 and supporter 10 contact well, and electric conductive property is good, and seal assembly's structure is more stable, and is not fragile, simple process and with low costs.

The radially outer side of the seal body 20 is interference fitted with the outer ring 40 of the ball bearing 200, and the radially inner side of the seal body 20 is interference fitted with the inner ring 50 of the ball bearing 200. The resilient nature of the seal body 20 facilitates the installation of the seal assembly between the inner ring 50 and the outer ring 40 of the ball bearing 200 without breaking or fracturing. The conductive properties of the sealing body 20, together with the conductive properties of the metal of the support body 10, allow electrical continuity between the outer ring 40 and the inner ring 50 of the ball bearing 200, avoiding charge accumulation.

In some embodiments, the sealing body 20 includes a primary sealing lip 21 and a secondary sealing lip 22. The main seal lip 21 is wrapped at the first end 11 of the support body 10, and the main seal lip 21 is provided with an oil through hole 211 which penetrates in the axial direction; the secondary sealing lip 22 wraps around the second end 12 of the support body 10.

In some embodiments, the shape of the oil passing hole 211 is one or a combination of semicircular, U-shaped, rectangular, triangular and inverted trapezoid, which is not limited herein.

The oil passing hole 211 may be a closed-loop hole, and the oil passing hole 211 may be an open hole that opens radially outward of the main seal lip 21. In the embodiment of the present disclosure, the oil passing hole 211 penetrates not only the main seal lip 21 in the axial direction but also an opening is provided radially outside the main seal lip 21.

In this way, the oil passing hole 211 is configured to reduce a contact area between the radially outer side of the main seal lip 21 and the inner wall of the outer ring 40 of the ball bearing 200. Therefore, the pressing force of the outer ring 40 against the main seal lip 21 is reduced, thereby reducing the friction force and torque of the main seal lip 21 against the bracket of the outer ring 40. The main seal lip 21 is made to rotate more easily with respect to the outer ring 40 and not to run. Race means that the seal assembly rotates relative to both the inner ring 50 and the outer ring 40, resulting in seal failure.

In some embodiments, as shown in fig. 2 and 3, the oil passing hole 211 is provided with one or more. In the embodiment of the present disclosure, the oil passing holes 211 are provided in plurality, and the oil passing holes 211 are arranged at equal intervals (as shown in fig. 2) or at unequal intervals in the circumferential direction of the main seal lip 21.

When electric drive wheel hub's motor shaft rotated at a high speed, the motor shaft produced centrifugal force, and lubricating oil tends to keep away from the direction of motor shaft and gets rid of under the centrifugal force effect, crosses the oilhole 211 and sets up the one end of keeping away from the motor shaft at seal 20, and the more be convenient for receive seal 20 axial outside receive centrifugal force and get rid of the lubricating oil of coming.

The plurality of oil passing holes 211 also allows the lubricant oil on the outer side in the axial direction of the seal body 20 (i.e., the gear housing) to enter the inner side in the axial direction of the seal body 20 as much as possible, so that the ball bearing 200 forms a thick oil film, and charge accumulation due to an excessively thin oil film is avoided.

In some embodiments, a abradable seal layer 30 is attached to one or both sides of the primary seal lip 21. The abradable seal 30 may be raised, recessed or flush with the side of the primary seal lip 21. In the embodiment of the present disclosure, the abradable seal layer 30 is attached to the side of the main seal lip 21 close to the first side 13, i.e., the abradable seal layer 30 is disposed axially inward of the main seal lip 21 and flush with the side surface of the main seal lip 21. The wear-resistant sealing layer 30 is in a ring shape, and the wear-resistant sealing layer 30 is in a discontinuous ring shape due to the arrangement of the through holes of the oil passing holes 211 of the wear-resistant sealing layer 30.

The wear-resistant seal layer 30 is made of Polytetrafluoroethylene (PTFE). The wear-resistant sealing layer 30 made of PTFE material has the functions of wear resistance and lubrication, when the sealing assembly is assembled, the wear-resistant sealing layer 30 is abutted to the outer ring 40, so that the friction force between the sealing body 20 and the outer ring 40 can be reduced, the main sealing lip 21 and the outer ring 40 are further enabled to rotate relatively, and the sealing assembly is prevented from circling.

In conclusion, the oil passing hole 211 is formed in the main seal lip 21 of the seal body 20 (i.e., the end away from the motor shaft), so that the lubricating oil under the action of centrifugal force can be more favorably received and passed through the oil passing hole 211, and meanwhile, the oil passing hole 211 and the wear-resistant seal layer 30 are both formed in the main seal lip 21 of the seal body 20, and under the combined action of the oil passing hole 211 and the wear-resistant seal layer, the friction force and the relative torque between the main seal lip 21 and the outer ring 40 can be reduced, so that the seal assembly can more conveniently rotate relative to the outer ring 40, and the seal assembly is prevented from circling.

In addition, PTFE also has high-efficient electric conductivity, can derive the electric charge accumulated on the axle or bearing in time, avoid producing lubricating oil burning or producing the washboard damage of bearing raceway that too big axle voltage leads to, protect bearing or axle structure, increase of service life.

As further shown in FIG. 2, the inner wall of the outer ring 40 is provided with a first annular groove 41, the outer wall of the inner ring 50 is provided with a second annular groove 51, and the first and second annular grooves 41, 51 are diametrically opposed to each other for receiving a seal assembly.

A portion of the primary seal lip 21 of the seal body 20 is disposed in the first annular groove 41 and in interference fit with the first annular groove 41, and a portion of the secondary seal lip 22 of the seal body 20 is disposed in the second annular groove 51 and in interference fit with the second annular groove 51.

Further, in some embodiments, the secondary sealing lip 22 extends toward the first side 13 of the support body 10 such that the secondary sealing lip 22 is hook-shaped. I.e. the secondary sealing lip 22 has an interference fit with the second annular groove 51 both axially and radially. Therefore, the friction and torque of the secondary seal lip 22 against the inner ring 50 are further increased. Furthermore, the secondary sealing lip 22 extends toward the first side 13 of the support body 10, and it is also possible to avoid the lubricating oil located on the axially inner side from overflowing.

Further, in some embodiments, the radially inner side of the secondary sealing lip 22 may be provided with one or more grooves 221. The groove 221 is an annular groove, and can further increase the frictional force between the radially outer side of the secondary seal lip 22 and the second annular groove 51.

So, inferior seal lip 22's structure for the frictional force of inferior seal lip 22 and inner ring 50 is far greater than the frictional force of main seal lip 21 and outer loop 40, makes can coaxial rotation between inferior seal lip 22 and the inner ring 50, and main seal lip 21 rotates with outer loop 40 relatively, and seal assembly is difficult for the race.

In some embodiments, the primary seal lip 21 extends obliquely toward the second side 14 of the support body 10 and away from the second end 12 such that the primary seal lip 21 is obliquely disposed relative to the support body 10.

The main seal lip 21 that the slope set up, when seal assembly installs, on the one hand, the bending part plays the effect of buffering, and when whole seal assembly and inner ring 50 and outer loop 40 interference fit, avoid main seal lip 21 to break or fracture. On the other hand, the wear-resistant sealing layer 30 is positioned on the axial inner side of the sealing body 20, and the main sealing lip 21 is obliquely arranged, so that the wear-resistant sealing layer 30 can be abutted to the inner wall of the first annular groove 41 as much as possible, the contact area is large, the electric conductivity is good, and the lubrication degree is increased.

On the other hand, when the sealing assembly works, when lubricating oil on the axial outer side of the sealing assembly enters the oil passing hole 211 under the action of centrifugal force, the main sealing lip 21 can be extruded towards the axial inner side, under the action, the obliquely arranged main sealing lip 21 can be further bent and is not easy to break, the main sealing lip 21 after being further bent is attached to the first annular groove 41 of the outer ring 40 more tightly, the electric conduction performance is improved, and the lubrication degree is increased.

Based on the same inventive concept, the present disclosure also provides a sealing structure 100, including: the seal comprises an outer ring 40, an inner ring 50, balls 60 and a seal assembly, wherein the seal assembly is arranged between the inner ring 50 and the outer ring 40 in an interference fit mode and used for sealing, oil passing and electric conduction.

The primary seal lip 21 of the seal body 20 is in interference fit with the first annular groove 41 and rotates relative to the outer ring 40, and the secondary seal lip 22 of the seal body 20 is in interference fit with the second annular groove 51 and coaxially rotates relative to the inner ring 50, so that the seal assembly can avoid the run-out.

In addition, a seal assembly may be provided axially on both sides of the ball 60. The sealing assemblies on either side of the ball 60 may be the same or different. Specifically, when the driving motor for the electric drive hub can be oil-drained, the seal assemblies on both sides of the ball 60 can be the same. When the drive motor needs to avoid the entry of lubrication, a seal assembly having no oil passing hole 211 may be provided on the axially inner side (i.e., the left side in fig. 2) of the ball 60 so as to avoid the entry of the lubricating oil in the ball bearing 200 into the drive motor.

The detailed description about the functions realized in the seal structure 100 in the above embodiment has been described in detail in the embodiment related to the seal assembly 100, and will not be explained in detail here.

Therein, it is to be understood that the term "rotationally fixed connection" means a connection between two elements in a manner that does not rotate relative to each other, which may be achieved via a press fit (i.e. an interference fit), or by integrally forming the two parts mentioned. The specific meaning of the above terms in the present invention can be understood as appropriate to those of ordinary skill in the art.

It is understood that "plurality" in this disclosure means two or more, and other terms are analogous. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. The singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It will be further understood that the terms "first," "second," and the like are used to describe various structures, but these structures should not be limited by these terms. These terms are only used to distinguish one type of structure from another and do not denote a particular order or importance. Indeed, the terms "first," "second," and the like are fully interchangeable. For example, a first structure may also be referred to as a second structure, and similarly, a second structure may also be referred to as a first structure, without departing from the scope of the present disclosure.

It will be further understood that the terms "central," "longitudinal," "lateral," "front," "rear," "upper," "lower," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship indicated in the drawings for convenience in describing the present embodiment and to simplify the description, but do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation.

It will be further understood that, unless otherwise specified, "connected" includes direct connections between the two without the presence of other elements, as well as indirect connections between the two with the presence of other elements.

It is further to be understood that while operations are depicted in the drawings in a particular order, this is not to be understood as requiring that such operations be performed in the particular order shown or in serial order, or that all illustrated operations be performed, to achieve desirable results. In certain environments, multitasking and parallel processing may be advantageous.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice in the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It will be understood that the present disclosure is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is to be limited only by the scope of the appended claims.

Claims (10)

1. A seal assembly, comprising:

a support body (10) comprising a first end (11) and a second end (12) which are diametrically opposite;

a sealing body (20) attached to the support body (10), the sealing body (20) including:

a main seal lip (21) wrapping the first end (11) of the support body (10), the main seal lip (21) being provided with an oil passing hole (211) which axially penetrates through,

a secondary sealing lip (22) wrapping the second end (12) of the support body (10);

a wear seal layer (30) attached to one or both sides of the primary seal lip (21).

2. The seal assembly of claim 1,

the support body (10) further comprises a first side (13) and a second side (14) axially opposite;

the wear-resistant sealing layer (30) is annular and attached to one side, close to the first side (13), of the main sealing lip (21).

3. The seal assembly of claim 2,

the main sealing lip (21) extends obliquely in the direction of the second side (14) of the support body (10) and away from the second end (12) such that the main sealing lip (21) is arranged obliquely relative to the support body (10).

4. The seal assembly of claim 2,

the secondary sealing lip (22) extends towards the first side (13) of the support body (10) such that the secondary sealing lip (22) is hook-shaped.

5. The seal assembly of claim 4,

one or more grooves (221) are arranged on the radial inner side of the secondary sealing lip (22).

6. The seal assembly of claim 1,

one or more oil passing holes (211) are arranged.

7. The seal assembly of claim 6,

the oil passing holes (211) are arranged in a plurality, and the oil passing holes (211) are arranged at equal intervals or at unequal intervals along the circumferential direction of the main seal lip (21).

8. The seal assembly of claim 1,

the support body (10) is made of an electrically conductive hard material by stamping;

the sealing body (20) is made of an electrically conductive elastic material; and

the abrasion-resistant sealing layer (30) is made of polytetrafluoroethylene.

9. The seal assembly of claim 1,

the oil passing hole (211) is in one or a combination of a plurality of semicircular shapes, U-shaped shapes, rectangular shapes, triangular shapes and inverted trapezoidal shapes.

10. A sealing structure, comprising:

an outer ring (40), the inner wall of the outer ring (40) being provided with a first annular groove (41);

the inner ring (50) rotates relative to the outer ring (40), and a second annular groove (51) is arranged on the outer wall of the inner ring (50) corresponding to the first annular groove (41); and

the seal assembly (100) of any one of claims 1 to 9, the seal assembly (100) being disposed between the first annular groove (41) and the second annular groove (51),

wherein, the primary seal lip (21) of sealing body (20) with first annular groove (41) interference fit, and relative outer ring (40) rotates, secondary seal lip (22) of sealing body (20) with second annular groove (51) interference fit, and relative inner ring (50) coaxial rotation.

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