CN111720187A

CN111720187A - Camshaft phaser and vehicle

Info

Publication number: CN111720187A
Application number: CN202010541706.4A
Authority: CN
Inventors: 林建刚
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Holding China Co Ltd
Priority date: 2020-06-15
Filing date: 2020-06-15
Publication date: 2020-09-29
Also published as: WO2021254188A1

Abstract

The invention provides a camshaft phaser and a vehicle. Rotor blades (21) and stator protrusions (11) of the camshaft phaser are arranged alternately in the circumferential direction to form a plurality of groups of cavities, each group of cavities comprises first cavities (A) and second cavities (B), a rotor body is formed with first cavity oil channels (22a) corresponding to the first cavities (A) and second cavity oil channels (22B) corresponding to the second cavities (B), the outer circumferential wall of the rotor body is provided with at least one oil groove (23) which is recessed towards the radial inner side, the oil groove (23) is communicated with one first cavity oil channel (22a) or one second cavity oil channel (22B), and the side wall of the oil groove (23) closest to one rotor blade (21) extends in the axial direction, when the rotor blade (21) comes into contact with the stator projection (11), the radially outwardly facing opening of the at least one oil groove (23) is completely shielded by the stator projection (11). The camshaft phaser has the advantages of simple structure, low cost and good deceleration and buffering effects.

Description

Camshaft phaser and vehicle

Technical Field

The invention relates to a camshaft phaser and a vehicle including the same.

Background

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

As shown in fig. 1 and 2, in order to avoid or reduce impact noise caused by mechanical contact of the stator projection 11 with the rotor blade 21 when the rotor 2 of the camshaft phaser rotates to extreme positions during circumferential rotation (including the rotor 2 rotating counterclockwise with respect to the stator 1 to a first extreme position where the rotor blade 21 and the stator projection 11 are in contact and the rotor 2 rotating clockwise with respect to the stator 1 to a second extreme position where the rotor blade 21 and the stator projection 11 are in contact), it is possible to provide two oil holes on both sides of the rotor blade 21 in the circumferential direction with an effect of adjusting the rotational speed of the rotor 2.

Taking the oil hole 22 located substantially at 12 o' clock in fig. 2 as an example, when the rotor 2 rotates counterclockwise relative to the stator 1 to make the rotor blade 21 approach the stator protrusion 11, the oil hole 22 is gradually blocked by the stator protrusion 11 and finally blocked by the stator protrusion 11, and the process from a to b to c in fig. 2 represents the process that the rotor 2 rotates counterclockwise gradually relative to the stator 1. In this process, for the first chamber a and the second chamber B separated by the stator 1 and the rotor 2, the first chamber a is filled with oil and the second chamber B is filled with oil. Because the area of the oil hole 22 which is opened towards the first chamber A is gradually reduced, the speed of the oil liquid flowing out of the first chamber A is gradually reduced, and the oil hole 22 is blocked at last, so that the oil liquid can only flow out of the first chamber A from a gap between the rotor 2 and the stator 1; in the process, the rotational speed of the rotor 2 relative to the stator 1 decreases, so that the rotor blades 21 are damped when approaching the first extreme position. However, the ideal damper adjustment process is expected to occur almost instantaneously when the rotor blades 21 contact the stator lobes 11, and the above damper adjustment process is too long, affecting the adjustment speed of the camshaft phase adjuster to some extent.

Chinese patent publication CN110388243A discloses a camshaft phaser in which an additional oil passage is provided between a stator boss and a rotor vane, the additional oil passage causing a flow path sectional area of a communication port communicating with a first chamber to gradually decrease as the rotor rotates clockwise relative to the stator. The scheme ensures the adjusting speed of the camshaft phaser to a certain extent. However, the adjustment speed of the camshaft phaser is still somewhat affected by the reduction in the cross-sectional area of the communication port.

Disclosure of Invention

The present invention is directed to overcoming, or at least reducing, the above-mentioned disadvantages of the prior art, and to providing a camshaft phaser having a simple structure, a good damping effect, and a small influence on the adjustment speed of the camshaft phaser, and a vehicle having the camshaft phaser.

According to a first aspect of the present invention, there is provided a camshaft phaser having an axial direction, a radial direction, and a circumferential direction and including a stator and a rotor, the rotor being disposed radially inward of the stator and being rotatable relative to the stator, the rotor including a rotor body and a plurality of rotor blades projecting radially outward from the rotor body, the stator including a stator body and a plurality of stator lobes projecting radially inward from the stator body, the plurality of rotor blades and the plurality of stator lobes being arranged alternately in the circumferential direction such that a plurality of sets of chambers distributed in the circumferential direction are formed, a set of chambers being formed between adjacent ones of the stator lobes, each set of chambers including first and second chambers partitioned by the rotor blade, the rotor body being formed with a first chamber oil passage corresponding to each of the first chambers and a second chamber oil passage corresponding to each of the second chambers, wherein the content of the first and second substances,

the peripheral wall of the rotor main body is provided with at least one oil groove which is sunken towards the radial inner side, each oil groove is communicated with one first cavity oil passage or one second cavity oil passage,

the side wall of the oil groove closest to one of the rotor blades extends in the axial direction,

when the rotor is rotated relative to the stator until the rotor blades contact the stator lobes, the radially outward opening of at least one of the oil grooves is completely shielded by the stator lobes.

In at least one embodiment, the radially outward opening of the oil groove satisfies:

in a process from a first circumferential position where the rotor rotates in one direction with respect to the stator to where the oil groove starts to be partially shielded by the stator protrusion to a time when the rotor continues to rotate in the one direction with respect to the stator through a non-buffer angle, an area of an opening of the oil groove facing a radially outer side is not smaller than an area of an opening of an oil passage communicating with the oil groove, the opening being located at an inner circumferential surface of the rotor.

In at least one embodiment, the magnitude of the non-buffering angle is 3 ° to 5 °.

In at least one embodiment, after the rotor is rotated relative to the stator in one direction until the radially outward opening of the oil sump is completely obscured by the stator lobes, the rotor can still rotate relative to the stator in the one direction through a buff angle until the rotor blades contact the stator lobes.

In at least one embodiment, the magnitude of the buffer angle is 2 ° to 3 °.

In at least one embodiment, there are at least two of the oil grooves, and the at least two oil grooves are respectively communicated with one of the first chamber oil passages and one of the second chamber oil passages.

In at least one embodiment, the oil groove extends in the axial direction to at least one end face of the rotor.

In at least one embodiment, the opening of the oil groove on the outer circumferential surface of the rotor is rectangular.

In at least one embodiment, the stator lobes have notches at radially inner, circumferential edges that communicate with the oil sump when the rotor rotates relative to the stator until the oil sump is partially obscured by the stator lobes.

According to a second aspect of the invention, a vehicle is provided that includes a camshaft phaser according to the present invention.

The camshaft phaser has the advantages of simple structure, low cost and good deceleration and buffering effects. Accordingly, a vehicle including the camshaft phaser of the present invention also has the advantages described above.

Drawings

Fig. 1 is a schematic diagram of one possible camshaft phaser with a damping function.

Fig. 2 is a schematic diagram of the camshaft phaser of fig. 1 performing a buff deceleration process.

Fig. 3 is a schematic diagram of a rotor of a camshaft phaser according to one embodiment of the present invention.

Fig. 4-6 are schematic diagrams of a camshaft phaser according to one embodiment of the present invention at various stages of operation.

Fig. 7 is a schematic diagram of a rotor of a camshaft phaser according to another embodiment of the present invention.

Description of the reference numerals

1, a stator; 11 a stator projection; 12, a notch;

2, a rotor; 21 a rotor blade; 22 oil holes; 22a first chamber oil passage; 22b a second chamber oil passage; 23 oil grooves;

a, a first chamber; b a second chamber;

x buffer angle; y a non-buffer angle;

l1 first circumferential position; a second circumferential position of L2; l3 third circumferential position.

Detailed Description

Exemplary embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the detailed description is intended only to teach one skilled in the art how to practice the invention, and is not intended to be exhaustive or to limit the scope of the invention.

A camshaft phaser according to the present invention is described with reference to fig. 3-7.

As shown in fig. 4, a camshaft phaser according to the present invention includes a stator 1 and a rotor 2, the rotor 2 being disposed radially inward of the stator 1 and being rotatable relative to the stator 1.

The stator 1 includes a cylindrical stator main body and a plurality of (four in the present embodiment) stator projections 11 that project radially inward from the stator main body. The rotor 2 includes a cylindrical rotor body and a plurality of (four in the present embodiment) rotor blades 21 that protrude radially outward from the rotor body. The plurality of stator lobes 11 and the plurality of rotor blades 21 are arranged alternately in the circumferential direction such that each rotor blade 21 is located between two adjacent stator lobes 11.

The space between two adjacent stator lobes 11 is divided into two chambers independent of each other by the rotor blade 21 located between the two stator lobes 11. At the tip of the rotor blade 21 a sealing assembly is provided in abutment with the stator body for isolating the two chambers from each other. Thus, four sets of circumferentially distributed chambers are formed in the camshaft phaser shown in fig. 4, each set of chambers including one first chamber a and one second chamber B.

All the first chambers a communicate with the oil supply device through the first chamber oil passages 22a formed in the rotor main body, and all the second chambers B communicate with the oil supply device through the second chamber oil passages 22B formed in the rotor main body. The first chamber oil passage 22a and the second chamber oil passage 22b are independent of each other. It is to be noted that only the oil passages related to the buffer structure are specifically shown in the drawings of the present application.

Referring also to fig. 3, at least one oil groove 23 recessed radially inward is provided in the outer circumferential wall of the rotor body, and the oil groove 23 communicates with an oil passage (the first chamber oil passage 22a or the second chamber oil passage 22 b). Preferably, there are at least two oil grooves 23, and one of the at least two oil grooves 23 communicates with the first chamber oil passage 22a and the other communicates with the second chamber oil passage 22 b. It is to be noted that, when only one oil groove is provided, the direction in which the rotor 2 rotates toward the base position with respect to the stator 1 is defined as the returning direction, and the one oil groove is provided on the returning direction side of the rotor blade 21.

In the embodiment shown in fig. 3, the oil groove 23 extends through the axial direction of the rotor 2, i.e. the oil groove 23 extends from one axial end face to the other axial end face of the rotor 2, however this is not essential. For example, referring to fig. 7, in another embodiment, the oil groove 23 extends from one axial end face of the rotor 2 to an axially middle region of the rotor 2. The arrangement in which the oil groove 23 extends to at least one axial end face of the rotor 2 facilitates the machining of the oil groove 23. It should be understood that, where the machining manner allows, the oil groove 23 may not extend to any one axial end face of the rotor 2, but may be located only in the axial middle region of the rotor 2, and only the oil groove 23 needs to be communicated with one oil passage.

Fig. 4 to 6 show three states during the counterclockwise rotation of the rotor 2 with respect to the stator 1, and next, the cushioning effect provided by the oil groove 23 to the rotor 2 will be described in connection with these three rotation states.

The presence of the oil groove 23 makes it possible to form a gap between the opening of the oil passage on the radially outer side of the rotor 2 and the inner circumferential surface of the stator projection 11, which gap can be used to store oil, when the rotor 2 is rotated relative to the stator 1 until the oil passage at least partially overlaps the stator projection 11 in the radial direction.

Referring to fig. 4, when at least one side wall (right side wall in the drawing) of the oil groove 23 does not contact the inner circumferential wall of the stator protrusion 11, the oil in the first chamber a can enter the oil groove 23 from the clearance and then flow back to the oil supply device through the first chamber oil passage 22 a. In particular, the oil groove 23 satisfies: in the course from when the first side wall (left side wall in the drawing) of the oil groove 23 contacts the inner peripheral surface of the stator protrusion 11 (the left side wall of the oil groove 23 moves to the first circumferential position L1 where the oil groove 23 is just stopped by the stator protrusion 11) to when the oil groove 23 passes through the non-buffer angle y (the left side wall of the oil groove 23 moves to the second circumferential position L2) in the circumferential direction, the open area of the oil groove 23 (the area of the oil groove 23 not stopped by the stator protrusion 11) where oil can flow into the oil groove 23 is not smaller than the area of the opening of the first chamber oil passage 22a at the inner peripheral surface of the rotor 2, and the non-buffer angle y is, for example, 3 ° to 5 °. In this way, the flow rate of the oil flowing through the first chamber oil passage 22a is not affected during the rotation of the rotor 2 through the non-damping angle y, and therefore the rotor 2 is not decelerated prematurely.

Preferably, a side wall of the oil groove 23 closest to one of the rotor blades 21 (in the present embodiment, referring to fig. 4, a right side wall of the oil groove 23 for the oil groove 23 connected to the first chamber oil passage 22a, and a left side wall of the oil groove 23 for the oil groove 23 connected to the second chamber oil passage 22b) is a plane extending in the axial direction. More preferably, the opening of the oil groove 23 on the outer circumferential surface of the rotor 2 is rectangular. The above-described structural features of the oil groove 23 not only make the oil groove 23 easy to machine, but also ensure that the rotor 2 does not decelerate prematurely during rotation.

Preferably, the stator projection 11 has a notch 12 at a radially inner, circumferential edge, and when the rotor 2 is rotated relative to the stator 1 to a state where the oil groove 23 is partially shielded by the stator projection 11, the notch 12 facilitates the flow of oil into the oil groove 23, preventing the rotor 2 from being decelerated prematurely.

Referring to fig. 5, when the rotor 2 continues to rotate relative to the stator 1 until the second side wall (right side wall in the drawing) of the oil groove 23 also contacts the inner circumferential wall of the stator protrusion 11 (the right side wall of the oil groove 23 moves to the first circumferential position L1), the open area of the oil groove 23 is reduced to zero, and the rotor 2 starts to perform a desired deceleration buffer. After that, the oil in the first chamber a can only flow out of the first chamber a through the gap between the stator 1 and the rotor 2, and the rotation speed of the rotor 2 relative to the stator 1 is rapidly reduced.

Referring to fig. 6, when the rotor 2 continues to rotate relative to the stator 1 such that the second sidewall of the oil groove 23 rotates counterclockwise to the third circumferential position L3, the rotor blade 21 contacts the stator protrusion 11, the rotor 2 no longer rotates counterclockwise relative to the stator 1, and the deceleration buffering stage of the rotor 2 is completed. An angle (central angle) between the first circumferential position L1 and the third circumferential position L3 is defined as a cushioning angle x. The magnitude of the buffering angle x will influence the effect of the buffering speed regulation, and a person skilled in the art can design a reasonable value of the buffering angle x according to actual requirements, for example, the buffering angle x is 2 ° to 3 °, and more preferably, the buffering angle x is 2.5 °.

The invention has at least one of the following advantages:

(i) according to the invention, no additional part is needed when the camshaft phaser is improved, so that the rotor of the camshaft phaser can reasonably decelerate and buffer before rotating relative to the stator to reach the limit position, and the contact noise is reduced.

(ii) By controlling the size of the non-buffer angle y and the buffer angle x, the buffer speed of the rotor can be adjusted, so that the process of decelerating and buffering the rotor is started as early as possible to influence the normal work of the rotor.

Of course, the present invention is not limited to the above-described embodiments, and those skilled in the art can make various modifications to the above-described embodiments of the present invention without departing from the scope of the present invention under the teaching of the present invention. For example: the present invention does not limit the length, width and depth of the oil groove 23.

Claims

1. A camshaft phaser having an axial direction, a radial direction and a circumferential direction and comprising a stator (1) and a rotor (2), the rotor (2) being disposed radially inward of the stator (1) and being rotatable relative to the stator (1), the rotor (2) comprising a rotor body and a plurality of rotor vanes (21) projecting radially outward from the rotor body, the stator (1) comprising a stator body and a plurality of stator lobes (11) projecting radially inward from the stator body, the plurality of rotor vanes (21) and the plurality of stator lobes (11) being arranged circumferentially alternately such that a plurality of sets of chambers distributed circumferentially are formed, a set of chambers being formed between adjacent stator lobes (11), each set of chambers comprising a first chamber (A) and a second chamber (B) separated by the rotor vane (21), the rotor main body is formed with first chamber oil passages (22a) corresponding to the respective first chambers (A) and second chamber oil passages (22B) corresponding to the respective second chambers (B), wherein,

the outer peripheral wall of the rotor main body is provided with at least one oil groove (23) recessed radially inward, each oil groove (23) is communicated with one of the first chamber oil passages (22a) or one of the second chamber oil passages (22b),

the side wall of the oil groove (23) closest to one of the rotor blades (21) extends in the axial direction,

when the rotor (2) is rotated relative to the stator (1) until the rotor blades (21) contact the stator projection (11), the radially outwardly facing opening of the at least one oil groove (23) is completely shielded by the stator projection (11).

2. A camshaft phaser as claimed in claim 1, wherein the opening of the oil groove (23) towards the radial outside satisfies:

the area of the opening of the oil groove (23) facing the radially outer side is not smaller than the area of the opening of the oil passage communicating with the oil groove (23) at the inner peripheral surface of the rotor (2) from a first circumferential position (L1) at which the rotor (2) rotates in one direction relative to the stator (1) to the point at which the oil groove (23) starts to be partially shielded by the stator protrusion (11) to the point at which the rotor (2) continues to rotate in the one direction relative to the stator (1) through a non-damping angle (y).

3. A camshaft phaser as in claim 2 wherein the magnitude of the undamped angle (y) is 3 ° to 5 °.

4. A camshaft phaser as claimed in claim 1, wherein when the rotor (2) is rotated relative to the stator (1) in one direction until the radially outward opening of the oil groove (23) is fully shielded by the stator lobe (11), the rotor (2) can still be rotated relative to the stator (1) in said one direction through a damping angle (x) until the rotor vane (21) contacts the stator lobe (11).

5. A camshaft phaser as in claim 4 wherein the magnitude of the lash angle (x) is 2 ° to 3 °.

6. A camshaft phaser as in any of claims 1-5, characterized in that there are at least two of said oil grooves (23), said at least two oil grooves (23) communicating with one said first chamber oil passage (22a) and one said second chamber oil passage (22b), respectively.

7. A camshaft phaser as claimed in any one of claims 1 to 5, characterized in that the oil groove (23) extends in the axial direction to at least one end face of the rotor (2).

8. A camshaft phaser as in any of claims 1-5, characterized in that the opening of the oil groove (23) on the outer circumference of the rotor (2) is rectangular.

9. A camshaft phaser as in any of claims 1-5, characterized in that the stator lobe (11) has a notch (12) at a radially inner, circumferential edge, the notch (12) communicating with the oil groove (23) when the rotor (2) is rotated relative to the stator (1) until the oil groove (23) is partially shielded by the stator lobe (11).

10. A vehicle comprising a camshaft phaser as claimed in any one of claims 1 to 9.