CN110836133B

CN110836133B - Camshaft phaser

Info

Publication number: CN110836133B
Application number: CN201810935029.7A
Authority: CN
Inventors: 何艳桦; 陈宇
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Holding China Co Ltd
Priority date: 2018-08-16
Filing date: 2018-08-16
Publication date: 2023-04-14
Anticipated expiration: 2038-08-16
Also published as: CN110836133A

Abstract

The invention relates to a camshaft phaser. The camshaft phaser includes a stator, a rotor, and a seal cover forming a plurality of oil chambers distributed circumferentially between the stator, rotor, and seal cover. The sealing cover is provided with a plurality of through holes which extend along the axial direction and penetrate through the sealing cover, each oil cavity is communicated with at least one through hole, and each through hole is provided with a control valve which can enable the through hole to be communicated/closed, so that the through hole is controlled to be communicated only when the oil pressure in the oil cavity is larger than a preset value. Therefore, the camshaft phaser can control the oil pressure in an oil cavity inside the camshaft phaser and eliminate high oil pressure, so that the reliability of the camshaft phaser is improved; in addition, by controlling the oil pressure, the load that parts of the camshaft phaser need to bear is reduced, the requirements of the relevant parts on material properties such as tensile strength and fatigue strength are reduced, and the manufacturing cost can be saved.

Description

Camshaft phaser

Technical Field

The invention relates to a camshaft phaser.

Background

In the prior art, an engine valve timing system is a system for controlling the valve opening and closing times of an engine of an automobile, and the engine valve timing system optimizes the operating performance of the engine by controlling the opening and closing of valves. Camshaft phasers are one of the most important components of an engine valve timing system.

Generally, a camshaft phaser according to the prior art includes a stator, a rotor, and an end cover (seal cover). The end caps are fixed to the stator from both axial sides. The rotor is disposed radially inward of the stator and is rotatable relative to the stator. The stator includes a cylindrical stator main body and a plurality of stator projections projecting radially inward from the stator main body. The rotor includes a cylindrical rotor body and a plurality of rotor blades extending radially outward from the rotor body. The plurality of stator lobes are circumferentially alternating with the plurality of rotor blades such that each rotor blade is located between two adjacent stator lobes. In this way, the space enclosed between two adjacent stator lobes and the end cover is divided into two oil chambers independent of each other by the rotor blade located between the two stator lobes. In addition, a seal assembly is provided at the tip of the rotor blade in abutment with the stator body for isolating the two oil chambers from each other. In this way, the camshaft phaser according to the related art forms a plurality of sets of oil chambers distributed along the circumferential direction, each set of oil chambers being respectively located between two adjacent stator protrusions and including two oil chambers, the two oil chambers being respectively communicated with the oil supply device through independent oil passages formed in the rotor main body, so that the two oil chambers can be respectively supplied with the engine oil through the oil passages. The position of the rotor relative to the stator is controlled by the pressure differential created by the filling oil in the two oil chambers. However, during operation of the camshaft phaser, the oil pressure of the oil in each oil chamber may be too high and adversely affect the reliability and manufacturing cost of the camshaft phaser.

Disclosure of Invention

The present invention has been made to overcome the above-mentioned drawbacks of the prior art. An object of the present invention is to provide a novel camshaft phaser capable of eliminating adverse effects on reliability and manufacturing cost of the camshaft phaser caused by an excessively high oil pressure in an oil chamber of the camshaft phaser.

In order to achieve the above object, the present invention adopts the following technical means.

The invention provides a camshaft phaser, which comprises a stator, a rotor and a sealing cover, wherein the sealing cover is fixed on the stator, the rotor is arranged on the radial inner side of the stator and can rotate relative to the stator and the sealing cover, a plurality of oil cavities distributed along the circumferential direction are formed among the stator, the rotor and the sealing cover, the sealing cover is provided with a plurality of through holes extending along the axial direction and penetrating through the sealing cover, the first end of each through hole is opened towards one axial side of the sealing cover, each oil cavity is respectively communicated with the second end of at least one through hole, and each through hole is provided with a control valve capable of enabling the through hole to be communicated/closed, so that the control valve controls the through hole to be communicated only when the oil pressure in the oil cavity is larger than a preset value.

Preferably, the rotor includes a rotor main body and a plurality of rotor blades projecting from the rotor main body toward a radially outer side, the stator includes a stator main body and a plurality of stator projections projecting from the stator main body toward a radially inner side, the plurality of rotor blades and the plurality of stator projections are arranged alternately in a circumferential direction such that the oil chamber is formed between the stator projections and the rotor blades adjacent to each other, and each of the oil chambers includes an abutting portion abutting with the stator projection for forming the oil chamber, and the second end of the through hole communicates with the abutting portion.

More preferably, a circumferential side portion of the stator projection is formed with an abutment portion projecting toward the circumferential direction for abutment with the rotor blade, the abutment portion being a portion of the oil chamber located radially outside and/or radially inside of the abutment portion.

Preferably, the control valve comprises a closing part and an elastic part fixedly connected with the closing part, and the elastic part can pivot relative to the sealing cover to push the closing part to move between a closing position for closing the through hole and a conducting position for conducting the through hole.

More preferably, the closing portion is capable of opening/closing an opening of the first end of the through hole to make the through hole conductive/closed.

More preferably, the camshaft phaser further includes an end cover fixed to the seal cover from one axial side and provided with both the closing portion and the elastic portion.

More preferably, the end cap comprises: an end cap body; a strip-shaped leaf spring as the elastic portion, the strip-shaped leaf spring being formed inside the end cover main body and extending in a radial direction, only one radial end of the strip-shaped leaf spring being fixed to the end cover main body so that the strip-shaped leaf spring can pivot about the one radial end; and the cover plate is used as the closing part and is fixed at the other radial end of the strip-shaped leaf spring and can move between the closing position and the conducting position along with the pivoting of the leaf spring.

More preferably, the end cover main body is formed with mounting holes corresponding to the strip-shaped leaf spring and the cover plate, and the strip-shaped leaf spring is fixed to the periphery of the mounting hole, so that the strip-shaped leaf spring and the cover plate are both located inside the mounting hole.

More preferably, the end cap is obtained by stamping a metal plate.

Preferably, the plurality of oil chambers correspond to the plurality of through holes one to one.

By adopting the technical scheme, the invention provides the novel camshaft phaser, the through holes communicated with the oil cavities are formed in the sealing cover, and the conduction/sealing of the through holes can be controlled by the control valve, so that the through holes are controlled to be conducted only when the oil pressure in the oil cavities is overlarge, and the engine oil can flow out of the oil cavities through the through holes when the oil pressure is overlarge.

Therefore, the novel camshaft phaser can control the oil pressure in an oil cavity inside the novel camshaft phaser and eliminate high oil pressure, so that the reliability of the camshaft phaser is improved; in addition, by controlling the oil pressure, the load that the parts of the camshaft phaser need to bear is reduced, the requirements of the relevant parts on the material performance such as tensile strength and fatigue strength are reduced, and the manufacturing cost can be saved.

Drawings

FIG. 1a is a schematic perspective view showing a partial structure of a camshaft phaser according to an embodiment of the present invention; fig. 1b is a schematic front view of the camshaft phaser of fig. 1a, showing the internal structure of the camshaft phaser in a perspective view and omitting a portion of the stator lobes.

Fig. 2 is a schematic front view of a seal cap of the camshaft phaser of fig. 1 a.

Fig. 3 is a schematic front view of an end cap of the camshaft phaser of fig. 1 a.

Description of the reference numerals

1. Stator 11 stator body 12 stator projection 13 abutting part 2 rotor 21 rotor body 22 rotor blade 3 gland 31 through hole 32 gland fixation hole 4 end cover 41 end cover body 42 strip leaf spring 43 cover plate 44 mounting hole 45 end cover fixation hole

A first oil chamber A1 a first adjoining portion B a second oil chamber B1 a second adjoining portion

AX axial C circumferential direction

Detailed Description

The following description will be made in conjunction with the accompanying drawings. The camshaft phaser according to the present invention has a generally cylindrical shape as a whole, and unless otherwise specified, the axial, radial and circumferential directions of the present invention refer to the axial, radial and circumferential directions of the camshaft phaser, respectively; one axial side refers to the left side in fig. 1a, and the other axial side refers to the right side in fig. 1 a.

As shown in fig. 1a and 1b, a camshaft phaser according to an embodiment of the present invention includes a stator 1, a rotor 2, a seal cover 3, and an end cover 4.

In the present embodiment, the stator 1 includes a cylindrical stator body 11 and four stator protrusions 12 protruding radially inward from the stator body 11. The four stator lobes 12 each extend in a radial direction and are evenly distributed in the circumferential direction C.

In the present embodiment, the rotor 2 is provided radially inside the stator 1 and is rotatable with respect to the stator 1. The rotor 2 includes a cylindrical rotor body 21 and four rotor blades 22 projecting radially outward from the rotor body 21. The four rotor blades 22 each extend in the radial direction and are distributed uniformly in the circumferential direction C.

The four stator lobes 12 are arranged alternately with the four rotor blades 22 in the circumferential direction C such that each rotor blade 22 is located between two adjacent stator lobes 12. Thus, the space between two adjacent stator projections 12 is partitioned into two first oil chambers a and second oil chambers B independent of each other by the rotor blade 22 located between the two stator projections 12. Further, a seal assembly abutting against the stator main body 11 is provided at the tip of the rotor blade 22 for isolating the two oil chambers a, B from each other.

Thus, in the camshaft phaser shown in fig. 1B, four sets of oil chambers distributed along the circumferential direction C are formed in common, each set of oil chambers including one first oil chamber a and one second oil chamber B, which are respectively communicated with the oil supply device through independent oil passages formed in the rotor main body 21.

In the present embodiment, as shown in fig. 2, the seal cover 3 has a circular plate shape. The seal cover 3 is fixed to one axial side end of the stator body 11 of the stator 1 and aligned with the stator 1 such that the seal cover 3 forms the above-described oil chambers a, B together with the stator 1 and the rotor 2.

Further, the seal cover 3 is formed with eight through holes 31 and four seal cover fixing holes 32 extending along the axial direction AX and penetrating the seal cover 3. One axial side end (first end) of each through hole 31 is open to one axial side of the seal cover 3, and the other axial side end (second end) of each through hole 31 is open to one oil chamber a, B, respectively. Thus, the oil chambers a, B can be communicated with the outside of the camshaft phaser through the through hole 31. In addition, the position of the sealing cover fixing hole 32 corresponds to the position of the stator protrusion 12, and the sealing cover 3 can be fixed to the stator 1 by a fixing member passing through the sealing cover fixing hole 32. Thus, as shown in fig. 2, a layout is formed in which one seal cover fixing hole 32 is provided between two through holes 31 in the seal cover 3.

Further, as shown in fig. 1B, each oil chamber a, B includes an abutting portion A1, B1 abutting on the stator projection 12 for forming the oil chamber a, B, and the other axial side end of the through hole 31 communicates with the abutting portion A1, B1. In this way, even when the rotor blade 22 is rotated to the extreme position between the adjacent two stator projections 12, it is ensured that the through hole 31 is always kept in communication with the oil chambers a, B. In addition, a circumferential side portion of a part of the stator projections 12 is formed with an abutment portion 13 projecting toward the circumferential direction C for abutment with the rotor blade 22, and in this case, the abutment portions A1, B1 refer to portions of the oil chambers a, B located radially outside and/or radially inside of the abutment portion 13. Specifically, as shown in fig. 1B, the first oil chamber a includes a first abutting portion A1 located radially outside the abutting portion 13, and the second oil chamber B includes a second abutting portion B1 located radially outside the abutting portion 13. Thus, when the rotor blade 22 rotates to abut against the abutting portion 13 of the stator projection 12, it is still ensured that the through hole 31 and the oil chambers a, B are always kept in communication.

In the present embodiment, as shown in fig. 3, the end cap 4 has a circular plate shape, and the end cap 4 is fixed to one axial side end of the seal cover 3 and aligned with the seal cover 3. The end cap 4 includes an end cap body 41, a strip-shaped leaf spring 42 as an elastic portion, and a cover plate 43 as a closing portion (where the elastic portion and the closing portion constitute the control valve of the present invention).

Specifically, the end cover main body 41 has a circular plate shape and is formed with eight mounting holes 44 and four end cover fixing holes 45 distributed along the circumferential direction C. The position of the mounting hole 44 corresponds to the position of the through hole 31 of the sealing cover 3 and the shape of the mounting hole 44 matches the overall shape of the strip-shaped leaf spring 42 and the cover plate 43, the strip-shaped leaf spring 42 and the cover plate 43 being able to be mounted in the mounting hole 44. The position of the end cover fixing hole 45 corresponds to the position of the stator protrusion 12, and the end cover 4 can be fixed to the sealing cover 3 by a fixing member passing through the sealing cover fixing hole 32 and the end cover fixing hole 45, so that the stator 1, the sealing cover 3, and the end cover 4 are fixed together. Thus, as shown in fig. 3, the end cover 4 is formed with a layout in which one end cover fixing hole 45 is provided in the middle of two mounting holes 44.

The strip-shaped leaf springs 42 extend substantially linearly in the radial direction, respectively. The strip-shaped leaf spring 42 is disposed in the mounting hole 44 and only the radially inner end of the strip-shaped leaf spring 42 is fixed to the periphery of the mounting hole 44 of the end cover main body 41, so that the strip-shaped leaf spring 42 and the cover plate 43 are both located inside the mounting hole 44 and the strip-shaped leaf spring 42 can pivot about the radially inner end when in the closed position.

The cover plate 43 has a circular shape and is fixed to the radially outer end of the strip-shaped leaf spring 42. The cover plate 43 is movable as the strip-shaped leaf spring 42 pivots about its radially inner end (in a direction substantially perpendicular to the paper surface of fig. 3), so that the cover plate 43 can open/close the opening of the one axial end of the through-hole 31, thereby opening/closing the through-hole 31. In this way, the pivoting of the strip-shaped leaf spring 42 with respect to the gland 3 enables the cover plate 43 to move between a closed position, in which the through hole 31 is closed, and a conductive position, in which the through hole 31 is conductive.

The above has explained a specific structure of a camshaft phaser according to an embodiment of the present invention, which is capable of reducing the oil pressure in the oil chambers a, B via the following process.

When the oil pressure in the oil chambers a, B increases to be greater than a predetermined value, the oil pressure of the oil overcomes the spring force of the strip leaf spring 42 to push open the cover plate 43. The cover plate 43 is moved in a direction away from one axial end of the through-hole 31, thereby bringing the through-hole 31 into conduction. The oil flows out of the camshaft phaser through the through hole 31, reducing the oil pressure in the oil chambers a, B.

When the oil pressure in the oil chambers a, B falls below a predetermined value, the cover plate 43 moves toward a direction approaching the one axial side end of the through-hole 31 by the spring force of the strip-shaped leaf spring 42, eventually abuts against the seal cover 3 and closes the opening of the one axial side end of the through-hole 31, thereby closing the through-hole 31.

In addition, although the specific embodiments of the present invention have been described in detail in the foregoing, it should be noted that:

1. although the one-to-one correspondence relationship of the through holes 31 and the oil chambers a, B is described in the above specific embodiment, the present invention is not limited thereto. For example, one oil chamber a, B may be made to correspond to the plurality of through holes 31.

2. Although not specifically described in the above embodiments, it is to be understood that the end cover 4 is preferably obtained by punching a metal plate.

3. Although not specifically described in the above embodiment, it is to be understood that the size of the mounting hole 44 of the end cap 4 is preferably larger than the size of the strip leaf spring 42 and the cover plate 43, so that the end cap body 41 does not easily affect the pivoting of the strip leaf spring 42.

4. Although it has been described in the above embodiment that the strip-shaped leaf spring 42 as the elastic portion and the cover plate 43 as the closing portion are both provided to the end cover main body 41, the present invention is not limited thereto. The strip leaf spring 42 and the cover plate 43 may be provided directly to the sealing lid 3 without being provided to the end cover main body 41.

Claims

1. A camshaft phaser comprising a stator, a rotor and a seal cover, the seal cover being fixed to the stator, the rotor being disposed radially inward of the stator and being rotatable relative to the stator and the seal cover, a plurality of oil chambers being formed between the stator, the rotor and the seal cover and distributed circumferentially,

the sealing cover is provided with a plurality of through holes which extend along the axial direction and penetrate through the sealing cover, the first end of each through hole is opened towards one axial side of the sealing cover, each oil cavity is communicated with the second end of at least one through hole, and each through hole is provided with a control valve which can enable the through hole to be communicated/closed, so that the control valve controls the through hole to be communicated only when the oil pressure in the oil cavity is larger than a preset value.

2. The camshaft phaser of claim 1, wherein the rotor includes a rotor body and a plurality of rotor vanes projecting from the rotor body toward a radially outer side, the stator includes a stator body and a plurality of stator projections projecting from the stator body toward a radially inner side, the plurality of rotor vanes and the plurality of stator projections are arranged alternately in a circumferential direction such that the oil chamber is formed between the stator projections and the rotor vanes adjacent to each other, and

each of the oil chambers includes an abutting portion that abuts the stator boss for forming the oil chamber, and the second end of the through hole communicates with the abutting portion.

3. A camshaft phaser as claimed in claim 2, wherein the circumferential side of the stator projection is formed with an abutment projecting circumferentially for abutment with the rotor vane, the abutment being the part of the oil chamber radially outside and/or radially inside the abutment.

4. A camshaft phaser as claimed in any one of claims 1 to 3, wherein the control valve comprises a closure portion and a resilient portion fixedly connected with the closure portion, the resilient portion being pivotable relative to the seal cap to urge the closure portion to move between a closed position closing the through bore and an open position opening the through bore.

5. The camshaft phaser of claim 4, wherein the closure portion is capable of opening/closing an opening of the first end of the through bore to render the through bore conductive/closed.

6. A camshaft phaser as in claim 5 further comprising an end cap fixed to the seal cap from one axial side and having the closing portion and the resilient portion both disposed thereon.

7. The camshaft phaser of claim 6 wherein the end cap comprises:

an end cap body;

a strip-shaped leaf spring as the elastic portion, the strip-shaped leaf spring being formed inside the end cover main body and extending in a radial direction, only one radial end of the strip-shaped leaf spring being fixed to the end cover main body so that the strip-shaped leaf spring can pivot about the one radial end; and

and the cover plate is used as the closing part and is fixed at the other radial end of the strip-shaped leaf spring and can move between the closing position and the conducting position along with the pivoting of the leaf spring.

8. A camshaft phaser as in claim 7, wherein said end cap body is formed with a mounting hole corresponding to said strip leaf spring and said cover plate, said strip leaf spring being fixed to the periphery of said mounting hole such that said strip leaf spring and said cover plate are both located inside said mounting hole.

9. A camshaft phaser as in claim 8 wherein the end cap is obtained by stamping a metal plate.

10. A camshaft phaser as in any of claims 1-3, wherein said plurality of oil chambers are in one-to-one correspondence with said plurality of through holes.