CN111425581B

CN111425581B - Belt pulley decoupler

Info

Publication number: CN111425581B
Application number: CN201910019218.4A
Authority: CN
Inventors: 唐中伍; 刘轶琨; 李定
Original assignee: Schaeffler Holding China Co Ltd
Current assignee: Schaeffler Holding China Co Ltd
Priority date: 2019-01-09
Filing date: 2019-01-09
Publication date: 2024-08-30
Anticipated expiration: 2039-01-09
Also published as: CN111425581A

Abstract

The invention relates to a pulley decoupler. Disclosed is a pulley decoupler comprising: a pulley (10) comprising an axially extending cavity; a sleeve (20) coaxially and rotatably disposed in the cavity of the pulley (10), the sleeve (20) including a protrusion (23); a first sleeve (50) coaxially and torsionally disposed in the cavity of the pulley (10), the first sleeve (50) comprising a first support portion (52), the first support portion (52) being axially spaced from the projection (23); and a seal (100) provided between the first support portion (52) and the protruding portion (23), wherein the seal (100) is configured in a ring shape and includes an engaging portion (110) and a seal lip (120), the engaging portion (110) is connected to one of the first support portion (52) and the protruding portion (23), and the seal lip (120) is provided to abut against the other of the first support portion (52) and the protruding portion (23).

Description

Belt pulley decoupler

Technical Field

The invention relates to a pulley decoupler. More particularly, the present invention relates to a pulley decoupler having an end seal.

Background

The generator in the accessory drive has a very high moment of inertia and therefore has a very large impact on the operation of the pulley system. The pulley decoupler can compensate for torsional vibrations and torsional non-uniformities introduced into the belt drive from the crankshaft of the internal combustion engine. The pulley decoupler is typically disposed on the generator as a generator pulley decoupler (APD). The pulley decoupler allows the drive shaft of the generator to overrun or rotate at a higher speed than the pulley.

Pulley decouplers are known which are sealed on the side remote from the generator by means of end caps only, without seals being provided. Lubricant often leaks from the working chamber of the pulley decoupler. In testing of pulley decouplers, frequent removal and installation of the end caps is required and additional return of leaked lubricant to the working chamber is required. Since the end cap needs to be mounted on the pulley decoupler during testing, the temperature of the shaft end cannot be detected from the outside by the infrared sensor.

For this purpose, a pulley decoupler with a seal on the side remote from the generator is needed.

Disclosure of Invention

It is an object of the present invention to provide a pulley decoupler with a seal on the side remote from the generator. It is another object of the present invention to provide a pulley decoupler that prevents leakage of lubricant after removal of the end cap. It is another object of the present invention to provide a pulley decoupler that enables removal of the end cap during testing to externally sense the temperature of the shaft end.

One aspect of the present invention provides a pulley decoupler comprising: a pulley comprising an axially extending cavity; a sleeve coaxially and rotatably disposed in the cavity of the pulley, the sleeve including a protrusion; a first sleeve coaxially and torsionally disposed within the cavity of the pulley, the first sleeve comprising a first support portion axially spaced from the projection; and a seal disposed between the first support and the protrusion, wherein the seal is configured in a ring shape and includes an engagement portion and a seal lip, the engagement portion being connected to one of the first support and the protrusion, and the seal lip being disposed to abut against the other of the first support and the protrusion.

According to an embodiment of the invention, the engagement portion of the seal is connected to the protruding portion of the sleeve and the sealing lip of the seal is arranged against the first support portion of the first sleeve.

According to an embodiment of the invention, the engagement portion of the seal is sleeved on the end of the protruding portion of the sleeve facing the first support portion by elastic deformation.

According to an embodiment of the invention, the projection of the sleeve has a first surface facing axially towards the first sleeve and a second surface facing radially towards the pulley, the engagement portion of the seal having a stepped configuration to form an interference fit with the first and second surfaces of the projection, respectively.

According to an embodiment of the invention, the seal is made of a rubber material.

According to an embodiment of the invention, the sealing lip is arranged to extend obliquely from the joint towards the radially inner side.

According to an embodiment of the invention, the pulley decoupler has axially opposite first and second sides, the sleeve further comprises a first shaft portion that extends axially and a connecting portion that extends radially outward from an end of the first shaft portion at the first side to a protruding portion that extends axially from the connecting portion to the second side, and the first sleeve further comprises a second shaft portion that extends axially and is disposed radially between the first shaft portion and the pulley, and the first support portion extends radially inward from the second shaft portion.

According to an embodiment of the invention, the pulley decoupler further comprises: a torsion spring disposed axially around at least a portion of the first shaft portion of the sleeve; a wrap spring radially disposed between the pulley and the torsion spring; a second sleeve including a third shaft portion extending in an axial direction and disposed between the surrounding spring and the first sleeve in a radial direction, and a second support portion extending from the third shaft portion in a radial direction inward, an axial end portion of the torsion spring being supported on the connection portion and the second support portion of the second sleeve, respectively, and an axial end portion of the surrounding spring being supported on the first support portion of the first sleeve and the second support portion of the second sleeve, respectively; and an end cap connected to an end of the pulley on a first side.

According to an embodiment of the invention, the sleeve, the first sleeve, the second sleeve and the seal form a sealed annular receiving cavity, wherein the torsion spring and the surrounding spring are arranged in the annular receiving cavity.

According to the embodiment of the invention, the sealing element is arranged on the side, far away from the generator, of the belt pulley decoupler, so that the leakage of the lubricant from the working chamber can be effectively prevented or reduced, and the efficiency and the service life of the belt pulley decoupler are improved. Thus, frequent removal of the end caps to handle leaked lubricant is not required, further improving the efficiency of use of the pulley decoupler and reducing costs. Since leakage of the lubricant can be effectively prevented, the end cap can be detached from the pulley decoupler during testing to externally detect the temperature of the shaft end using an infrared sensor or the like.

Drawings

Fig. 1 is a cross-sectional view of a pulley decoupler.

Fig. 2 is a perspective exploded view of the pulley decoupler.

FIG. 3 is a cross-sectional view of a pulley decoupler having a seal according to an embodiment of the present invention.

Fig. 4 is an enlarged partial view of a pulley decoupler according to an embodiment of the present invention.

Detailed Description

Hereinafter, embodiments of the present invention are described with reference to the drawings. The following detailed description and drawings are provided to illustrate the principles of the invention and are not limited to the preferred embodiments described, the scope of which is defined by the claims. The invention will now be described in detail with reference to exemplary embodiments, some examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings in which the same reference numerals in different drawings represent the same or similar elements, unless otherwise indicated. The schemes described in the following exemplary embodiments do not represent all schemes of the present invention. Rather, these are merely examples of systems and methods of various aspects of the present invention that are set forth in the following claims.

Fig. 1 is a cross-sectional view of a pulley decoupler. Fig. 2 is a perspective exploded view of the pulley decoupler. The pulley decoupler may include a pulley 10, a sleeve 20, a torsion spring 30, a wrap spring 40, a first sleeve 50, a second sleeve 60, and an end cap 70. The pulley decoupler has an axis of rotation X and has axially opposite first and second sides a and B. In the exemplary embodiment, first side A is the side that is remote from the generator (not shown) and second side B is the side that is proximate to the generator.

Pulley 10 may have a hollow cylindrical structure. Pulley 10 includes an axially extending cavity. Pulley 10 includes an outer surface 11 wrapped by a belt (not shown) that may be formed according to the multi-groove shape (multi-V-groove shape) of the belt. The belt may drive pulley 10 in a direction perpendicular to the plane of the paper in fig. 1.

Sleeve 20 may be coaxially disposed within the cavity of pulley 10. Pulley 10 is rotatably supported on sleeve 20. The sleeve 20 may include a shaft portion 21, a connecting portion 22, and a protruding portion 23. The shaft portion 21 and the protruding portion 23 extend in the axial direction. The connecting portion 22 extends radially outwardly from the end of the shaft portion 21 at the first side a to the protruding portion 23. The protruding portion 23 extends from the connecting portion 22 toward the second side B in the axial direction.

The hub 20 may be fixedly connected to a generator shaft (not shown) by threads. For this purpose, the sleeve 20 may have an internal thread, not shown, on the middle section 24 and an internal tooth 25 on the end section at the first side a. Pulley 10 may be rotatably supported at both axial ends on sleeve 20 by a sliding bearing 81 and a rolling bearing 82, respectively. The sleeve 20 may form an annular groove 26 on the radially outer surface of the projection 23 to accommodate the sliding bearing 81.

Torsion spring 30 and wrap spring 40 form a series connection to transfer torque between pulley 10 and sleeve 20. The torsion spring 30 is configured as a helical torsion spring. Torsion spring 30 and wrap spring 40 are disposed to extend coaxially along the axial direction of the pulley decoupler.

The torsion spring 30 is disposed axially around at least a portion of the shaft portion 21 of the sleeve 20. Torsion spring 30 and wrap spring 40 are both disposed radially between pulley 10 and shaft portion 21 of sleeve 20. Wrap spring 40 is disposed radially between pulley 10 and torsion spring 30 and thus surrounds torsion spring 30.

The first sleeve 50 may include a shaft portion 51 and a support portion 52. Shaft portion 51 extends axially and is disposed radially between wrap spring 40 and pulley 10. Support portion 52 extends radially inward from shaft portion 51 and is disposed between torsion spring 30 and pulley 10. First sleeve 50 is disposed in the cavity of pulley 10 and is torsionally connected to pulley 10. For example, first sleeve 50 may be torsionally mounted in a cavity of pulley 10 by a press fit. According to an embodiment of the invention, the support portion 52 of the first sleeve 50 is axially spaced from the protruding portion 23 of the sleeve 20.

The second sleeve 60 includes a shaft portion 61 and a support portion 62. The shaft portion 61 extends in the axial direction and is disposed radially between the surrounding spring 40 and the first sleeve 50. The support portion 62 extends radially inward from the shaft portion 61.

The torsion spring 30 abuts on the end of the first side a against the connecting portion 22 of the sleeve 20 and on the end of the second side B against the support portion 62 of the second sleeve 60. The end of the wrap spring 40 at the first side a abuts the support 52 of the first sleeve 50 and the end at the second side B abuts the support 62 of the second sleeve 60.

End cap 70 may be connected to the end of pulley 10 at first side a, such as by a snap-fit connection. An end cap 70 may cover an end of the sleeve 20 to isolate the sleeve 20 from the external environment on the first side a.

During operation of the pulley decoupler, torque from pulley 10 is introduced into torsion spring 30 through friction between first sleeve 50 and wrap spring 40 and friction between wrap spring 40 and second sleeve 60. Thereafter, torque is transmitted from the torsion spring 30 to the boss 20 through friction between the second sleeve 60 and the torsion spring 30 and friction between the torsion spring 30 and the connection portion 22 of the boss 20. Wrap spring 40 allows the generator shaft and hub 20 secured thereto to overrun pulley 10 when torque is reversed. In this state, the wrap spring 40 slides within the two sleeves 50, 60 or one of the two sleeves.

In the pulley decoupler, lubricant is applied to the torsion spring 30, the wrap spring 40, the first and second sleeves 50, 60, etc., to reduce wear between the springs and the sleeves. However, as the pulley decoupler operates, lubricant will flow from the interior to the end cap 70 as shown by path C in fig. 1. Lubricant leaks to the end cap 70 and possibly to the outside of the pulley decoupler. Therefore, the springs and sleeves of the pulley decoupler cannot be sufficiently lubricated, which can affect the operation of the pulley decoupler and reduce its useful life.

The invention provides a seal for a pulley decoupler. FIG. 3 is a cross-sectional view of a pulley decoupler having a seal according to an embodiment of the present invention. Fig. 4 is an enlarged partial view of a pulley decoupler according to an embodiment of the present invention.

According to an embodiment of the present invention, a pulley decoupler may include a pulley 10, a sleeve 20, a torsion spring 30, a wrap spring 40, a first sleeve 50, a second sleeve 60, an end cap 70, and a seal 100. The structure of the pulley decoupler shown in fig. 3 and 4 is substantially the same as the pulley decoupler shown in fig. 1 except for the seal 100, and will not be described again.

According to an embodiment of the present invention, the seal 100 may be disposed between the support portion 52 of the first sleeve 50 and the protruding portion 23 of the sleeve 20. In the exemplary embodiment, seal 100 is configured in a ring shape. In an exemplary embodiment, as shown in fig. 3 and 4, the seal 100 may include an engagement portion 110 and a sealing lip 120. The joint 110 and the sealing lip 120 may be integrally formed.

In an exemplary embodiment, the engagement portion 110 of the seal 100 may be connected to the protrusion 23 of the sleeve 20. The engagement portion 110 may form an interference fit with the projection 23 of the sleeve 20. According to some embodiments of the invention, the seal 100 is an elastic seal and the engagement portion 110 is sleeved on the end of the projection 23 facing the second side B by elastic deformation.

According to some embodiments of the present invention, as shown in FIG. 4, the projection 23 of the sleeve 20 may have a first surface 27 facing axially toward the first sleeve 50 and a second surface 28 facing radially toward the pulley 10. The joint 110 may have a stepped structure. Thus, the engagement portion 110 of the seal 100 may be configured to engage both the first surface 27 and the second surface 28 of the protrusion 23.

The sealing lip 120 of the seal 100 may abut against the support portion 52 of the first sleeve 50, e.g., an axial surface of the support portion 52 facing the first side a. In some embodiments, the sealing lip 120 is disposed to extend obliquely from the joint 110 toward the radially inner side. For example, the sealing lip 120 may be inclined at an angle of between 45 and 60 degrees with respect to the rotation axis X.

According to an embodiment of the present invention, the sleeve 20, the first sleeve 50, the second sleeve 60, and the seal 100 may form a sealed annular receiving cavity in which the torsion spring 30 and the wrap spring 40 are both disposed. Thereby, the lubricant can be held in the annular housing chamber by the seal, so that leakage of the lubricant can be effectively prevented or reduced.

In the exemplary embodiment, seal 100 is fabricated from an elastomeric material. The elastic material may be a rubber material such as nitrile rubber, hydrogenated nitrile rubber, ethylene propylene diene rubber, fluororubber, and the like.

The engagement portion 110 of the seal 100 is connected to the projection 23 of the sleeve 20 and the sealing lip 120 abuts the support portion 52 of the first sleeve 50 as described above. But the present invention is not limited thereto. According to an embodiment of the invention, the engagement portion 110 of the seal 100 may be connected to the support portion 52 of the first sleeve 50 and the sealing lip 120 may abut against the projection 23 of the sleeve 20.

The joint 110 of the seal 100 is connected to the boss 20 by elastic deformation as described above. But the present invention is not limited thereto. According to an embodiment of the present invention, the joint 110 of the seal 100 may also be connected to the sleeve 20 or the first sleeve 50 by screws, clips, adhesive, or the like.

While the invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the constructions and methods of the above-described embodiments. On the contrary, the invention is intended to cover various modifications and equivalent arrangements. In addition, while the various elements and method steps of the disclosed invention are shown in various combinations and configurations, which are exemplary, other combinations, including more, less elements or methods, are also within the scope of the invention.

Claims

1. A pulley decoupler comprising:

A pulley (10) comprising an axially extending cavity;

-a sleeve (20) coaxially and rotatably arranged in said cavity of said pulley (10), said sleeve (20) comprising a protrusion (23);

-a first sleeve (50) coaxially and torsionally disposed in said cavity of said pulley (10), said first sleeve (50) comprising a first support portion (52), said first support portion (52) being axially spaced from said projection (23);

A seal (100) disposed between the first support (52) and the protrusion (23), wherein the seal (100) is configured in a ring shape and includes an engagement portion (110) and a seal lip (120), the engagement portion (110) being connected to one of the first support (52) and the protrusion (23), and the seal lip (120) being disposed against the other of the first support (52) and the protrusion (23); and

The second sleeve (60), the shaft sleeve (20), the first sleeve (50), the second sleeve (60) and the sealing element (100) form a sealed annular accommodating cavity, wherein, in a section through a central axis, the shaft sleeve (20), the sealing element (100), the first sleeve (50) and the second sleeve (60) are sequentially arranged along the section profile of the annular accommodating cavity, so that the annular accommodating cavity is closed.

2. Pulley decoupler according to claim 1, wherein the engagement portion (110) of the seal (100) is connected to the projection (23) of the sleeve (20) and the sealing lip (120) of the seal (100) is arranged against the first support (52) of the first sleeve (50).

3. Pulley decoupler according to claim 2, wherein the engagement portion (110) of the seal (100) is elastically deformed over the end of the projection (23) of the sleeve (20) facing the first support portion (52).

4. A pulley decoupler as claimed in claim 3, wherein the projection (23) of the sleeve (20) has a first surface (27) axially facing the first sleeve (50) and a second surface (28) radially facing the pulley (10), the engagement portion (110) of the seal (100) having a stepped configuration to form an interference fit with the first surface (27) and the second surface (28) of the projection (23), respectively.

5. Pulley decoupler according to any one of claims 1 to 4, wherein the seal (100) is made of a rubber material.

6. Pulley decoupler according to any one of claims 1 to 4, wherein the sealing lip (120) is provided extending obliquely from the joint (110) towards the radially inner side.

7. Pulley decoupler according to any one of claims 1 to 4, wherein the pulley decoupler has a first side (a) and a second side (B) that are axially opposite,

The sleeve (20) further comprises a first shaft part (21) and a connecting part (22), the first shaft part (21) extending in an axial direction, the connecting part (22) extending radially outwards from the first shaft part (21) at the end of the first side (A) to the protruding part (23), the protruding part (23) extending from the connecting part (22) in an axial direction to the second side (B), and

The first sleeve (50) further comprises a second shaft portion, the second shaft portion (51) extending in an axial direction and being arranged radially between the first shaft portion (21) and the pulley (10), the first support portion (52) extending radially inwards from the second shaft portion (51).

8. The pulley decoupler of claim 7, further comprising:

a torsion spring (30) disposed axially around at least a portion of the first shaft portion (21) of the sleeve (20);

-a wrap spring (40) radially arranged between the pulley (10) and the torsion spring (30); and

An end cap connected to an end of the pulley (10) at the first side (a);

The second sleeve (60) comprises a third shaft portion (61) and a second support portion (62), wherein the third shaft portion (61) extends axially and is arranged radially between the surrounding spring (40) and the first sleeve (50), the second support portion (62) extends radially inwards from the third shaft portion (61), axial ends of the torsion spring (30) are supported on the connecting portion (22) and the second support portion (62) of the second sleeve (60), respectively, axial ends of the surrounding spring (40) are supported on the first support portion (52) of the first sleeve (50) and the second support portion (62) of the second sleeve (60), respectively.

9. Pulley decoupler according to claim 8, wherein the torsion spring (30) and the wrap spring (40) are arranged in the annular housing cavity.