CN112384711A

CN112384711A - Spring retainer and centering type separation auxiliary cylinder

Info

Publication number: CN112384711A
Application number: CN201880095472.6A
Authority: CN
Inventors: 张斌; 郑飞翔
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2018-08-09
Filing date: 2018-08-09
Publication date: 2021-02-19
Also published as: WO2020029192A1; DE112018007896T5

Abstract

A spring holder (1) for a clutch release system and a centered release sub-cylinder (100), wherein the spring holder (1) serves to hold one end (20) of a spring (2) on the release bearing (3, 4) side of the centered release sub-cylinder (100), wherein the spring holder (1) has a stop face (12) extending in the axial direction of the centered release sub-cylinder (100) and located radially outside the end (20) of the spring (2), wherein the spring holder (1) further has a stop (10), wherein the stop (10) extends radially inside from the stop face (12), and wherein a side face (15) of the stop (10) which is in contact with the end (20) of the spring (2) intersects the radial direction of the spring holder (1), such that when the end (20) of the spring (2) is pressed against the side face (15), the end portion (20) of the spring (2) is easily slid radially inward. The spring holder (1) facilitates the end (20) of the spring (2) to pass over the stop, thereby avoiding a first coil of the spring (2) from moving axially out of the spring holder (1) or a second coil of the spring (2) from expanding radially outward.

Description

Spring retainer and centering type separation auxiliary cylinder

Technical Field

The present invention relates to a clutch release system, and particularly to a spring holder for holding one end of a spring on a release bearing side of a center type release sub-cylinder. The invention also relates to a centering splitter sub-cylinder comprising the spring holder described above.

Background

The release bearing of the Central Slave Cylinder (CSC) is connected to a spring via a spring retainer, the spring providing a preload to the release bearing and assisting the release bearing in self-aligning. The spring holder is located between the spring and the split sub-cylinder and serves to hold the spring in the radial and circumferential directions. The radial retention is achieved by the outer circumferential surface of the spring abutting against a stop surface of the spring holder, which stop surface is in contact with the spring, and the circumferential retention is achieved by a stop of the spring holder.

When the release bearing is in operation, the outer race is connected to and rotates with the clutch, while the inner race does not rotate. However, at low temperatures, particularly when the engine is started at high speeds, the lubrication provided by the grease is not ideal resulting in increased friction, and therefore the outer ring transfers torque to the inner ring, which also rotates. Since the spring holder and the inner ring cannot rotate relative to each other, in this case the spring holder will rotate relative to the spring, the end of the spring abutting against the stop will pass the stop, after which the spring holder will continue to rotate one revolution relative to the spring and its end and again return to the position in which the end abuts against the stop, thereby releasing a certain torque.

In the prior art, the stop is usually designed in the form of a ramp (fig. 2), the first coil of the spring being displaced in the axial direction relative to the spring holder when the end of the spring passes over the stop (compare fig. 3a and 3 b). Since the axial height of the stop surface located radially outside the spring is usually not very large, approximately equal to the wire diameter of the spring, it is very likely that the first turn of the spiral of the spring will be out of the limit of the stop surface to the axially outside of the spring holder when axial movement occurs. In addition, the stopping of the spring end by the stop in the prior art design does not make it particularly easy for the spring end to jump over the stop, so that when the torque is large, the second turn of the coil of the spring is often expanded radially outward.

Disclosure of Invention

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and an object of the present invention is to provide a spring holder that allows an end portion of a spring to easily pass over a stopper portion, thereby preventing a first turn of a coil of the spring from moving axially out of the spring holder or a second turn of the coil of the spring from expanding radially outward.

A spring holder according to an embodiment of the present invention is for holding one end portion of a spring on a release bearing side of a center type release sub-cylinder, the spring holder having a stopper surface extending in an axial direction of the center type release sub-cylinder, the stopper surface being located radially outward of the end portion of the spring, the spring holder further having a stopper portion extending radially inward from the stopper surface, and a side surface of the stopper portion contacting the end portion of the spring intersecting with a radial direction of the spring holder, so that the end portion of the spring is liable to slip radially inward when the end portion of the spring is pressed against the side surface.

In particular, the axial height of the stop face of the spring holder is approximately equal to twice the wire diameter of the spring.

In particular, the side of the stop which is not in contact with the end of the spring also intersects the radial direction of the spring holder.

In particular, a side surface of the stopper portion that contacts the end portion of the spring is formed as a flat surface.

In particular, in a cross section of the stopper portion perpendicular to the axial direction, a side surface of the stopper portion contacting the end portion of the spring is formed in an arc shape.

In particular, in a cross section of the stopper portion perpendicular to the axial direction, the stopper portion is formed in a triangular shape, two apexes of which are located in the stopper surface, and the other apex of which is located radially inward of the stopper surface.

A centered secondary disconnect cylinder according to one embodiment of the present invention has the spring retainer described above.

In particular, the end of the spring extends obliquely with respect to the radial direction.

In particular, the end of the spring is formed in a hemispherical shape.

In particular, the spring holder includes a radially extending portion that axially abuts against the end portion of the spring, the stop surface extends from an outer peripheral edge of the radially extending portion toward one axial side, and a radial width a of the radially extending portion, a radial height h of the stop portion, and a wire diameter d of the spring satisfy the following condition: a is more than or equal to d + h.

The side of the stop of the spring holder that is in contact with the end of the spring according to the invention intersects the radial direction of the spring holder, so that the end of the spring easily passes over the stop, and thus avoids that the first turn of the coil of the spring moves axially out of the spring holder or that the second turn of the coil of the spring expands radially outwards.

Drawings

Fig. 1 shows a schematic axial cross-section of a medium-sized splitter sub-cylinder.

Fig. 2 is a perspective view showing a spring holder in the prior art.

Fig. 3a-3b show axial cross-sectional views of the spring holder shown in fig. 2.

Fig. 4 shows a perspective view of a spring holder according to an embodiment of the invention.

Fig. 5 shows a top view of a spring holder according to an embodiment of the invention, in which the spring accommodated therein is schematically shown.

Fig. 6a-6b show axial cross-sectional views of the spring holder shown in fig. 4.

Description of the reference numerals

1, 1' spring retainer; 2, a spring; 3 separating the outer ring of the bearing; 4 separating the inner ring of the bearing; 5, a cylinder body;

10, 10' stop; 11 an interference fit part; 12 a stop surface; 13 a holding part; 14 a radial extension; 15, 15' side of the stop in contact with the end of the spring; 20 ends of the spring;

100 middle separation auxiliary cylinder;

axial direction A; r is radial.

Detailed Description

The following description of the embodiments of the present invention refers to the accompanying drawings.

Fig. 1 shows a schematic axial cross-sectional view of a centered splitter sub-cylinder 100. The center type release sub-cylinder 100 has a spring 2, a release bearing (the release bearing includes an outer race 3 and an inner race 4), a cylinder 5, and a spring holder 1 that holds the spring 2 outside the cylinder 5 in the radial direction R. The axial direction a in the drawing is the axial direction of the center type split sub-cylinder 100.

Fig. 2 shows a perspective view of a spring holder 1' according to the prior art. The spring holder 1' has: a radially extending portion 14; a stop surface 12 extending from an outer peripheral edge of the radially extending portion 14 toward one axial side (cylinder 5 side); and a holding portion 13 extending from the inner peripheral edge of the radially extending portion 14 toward the other axial side (the release bearing side). After the spring holder 1' is fitted into the center type split sub-cylinder 100, the holding portion 13 is located radially inside the inner race 4, and the interference fit portion 11 formed on the holding portion 13 is protruded radially outside, thereby forming an interference fit with the inner race 4. The spring 2, which is not shown in fig. 2, rests against the stop surface 12 from the radial inside. A stop 10 'is formed radially on the inside of the stop surface 12, the stop 10' being designed in the form of a ramp. Such spring holders are usually manufactured in two steps, in which a ramp-like stop 10' is formed by stamping. The disadvantages here are: first, since the side surface 15 ' (e.g., the side shown in the drawings or the side opposite thereto) of the stopper portion 10 ' that contacts the end portion of the spring extends substantially in the radial direction, the end portion of the spring is less likely to slide radially inward on the side surface so as to pass over the stopper portion 10 '; secondly, after the end of the spring abutting against the stop has passed the stop 10 ', an axial movement takes place with respect to the spring holder 1 ', so that the first coil of the spring runs the risk of falling out of the spring holder 1 '.

Fig. 3a-3b show axial cross-sectional views of the spring holder shown in fig. 2. Fig. 3a shows that the end of the spring 2 bears radially against the stop surface 12. The stop 10 'abuts against the end of the spring 2 in the circumferential direction, thereby preventing the spring holder 1' and the spring 2 from rotating relative to each other. The end of the spring 2 in fig. 3b has already passed the stop 10 'in the circumferential direction and moved axially along the ramp relative to the spring holder 1'. It can be seen here that a part of the first coil of the spring is located axially outside the stop face 12 of the spring holder 1 ', and can therefore be pulled out of the spring holder 1'. Also visible in fig. 3a-3b are the retaining portion 13 and the interference fit portion 11.

Fig. 4 shows a perspective view of a spring holder according to an embodiment of the invention. The main differences between the spring holder 1 and the spring holder 1' are 1) the structure of the stop 10 and 2) the axial height of the stop surface 12. The spring holder 1 may be the same as the spring holder 1' except for this, and thus description about other parts is omitted. The stopper portion 10 extends radially inward from the stopper surface 12, and a side surface 15 of the stopper portion 10 that contacts the end of the spring intersects the radial direction of the spring holder 1. Depending on the arrangement of the spring ends, the side 15 of the stop 10 that is in contact with the spring ends can be the side shown in the figures or the side opposite to this side. The side which is not in contact with the end of the spring can then be designed to extend radially or also intersect the radial direction of the spring holder 1.

More specifically, in the example shown in fig. 4, the stopper portion 10 is substantially triangular in a cross section of the stopper portion 10 perpendicular to the axial direction a, and two opposite side surfaces of the stopper portion 10 in the circumferential direction of the spring holder 1 may be used to contact with the end of the spring. The side surface 15 may have a circular arc shape.

Fig. 5 shows a top view of a spring holder according to an embodiment of the invention, wherein the spring 2 accommodated in the spring holder is schematically shown. The end 20 of the spring 2 abuts against the side 15 of the stop 10. Here, the end face of the end portion 20 of the spring 2 is inclined with respect to the radial direction. Since the side surface 15 of the stop 10 that is in contact with the end of the spring intersects the radial direction of the spring holder 1, in particular is substantially parallel to the end surface of the end 20 of the spring, the end 20 of the spring is more easily elastically deformed radially inwards than in the prior art, so as to pass over the stop 10 without protruding from the stop surface in the axial direction a. In order to achieve the above-described operation, the radial width a of the radially extending portion 14, the radial height h of the stopper portion 10, and the wire diameter d of the spring have the following requirements: a is more than or equal to d + h.

It should be understood that the end surface of the end 20 of the spring 2 does not have to be a plane surface, and the end 20 of the spring 2 may also be formed in a rounded shape such as a hemisphere to facilitate the end 20 of the spring 2 to slide along the side surface 15.

Fig. 6a-6b show axial cross-sectional views of the spring holder shown in fig. 4. It can be seen in fig. 6a that the end 20 of the spring bears radially against the stop surface 12. The end 20 of the spring in fig. 6b is already located radially inside the stop 10. In the design according to the invention, the end 20 of the spring therefore passes beyond the stop 10 from the radially inner side, rather than axially as in the prior art, which reduces the risk of the end of the spring coming out of the spring holder 1 in the axial direction. Moreover, since the side face 15 of the stopper portion 10 contacting the end portion of the spring intersects with the radial direction of the spring holder 1, the side face 15 cooperates with the end portion 20 of the spring so that the end portion 20 of the spring more easily passes over the stopper portion 10. The stop face 12 shown in the figures is only schematically illustrated, and it can be seen that the axial height of the stop face according to the invention is greater, preferably twice the wire diameter of the spring, with respect to the stop faces of the prior art.

The scope of the present invention is not limited to the specific examples described in the above-described embodiments, but falls within the scope of the present invention as long as the combinations of the technical features of the claims of the present invention are satisfied.

Claims

A spring holder for holding one end portion of a spring on a release bearing side of a split center sub-cylinder, the spring holder having a stop surface extending in an axial direction of the split center sub-cylinder, the stop surface being located radially outward of the end portion of the spring, characterized in that the spring holder further has a stopper portion extending radially inward from the stop surface, and a side surface of the stopper portion that is in contact with the end portion of the spring intersects with a radial direction of the spring holder, so that the end portion of the spring is susceptible to slipping radially inward when the end portion of the spring is pressed against the side surface.
The spring holder of claim 1, wherein the axial height of the stop surface of the spring holder is substantially equal to twice the wire diameter of the spring.
The spring holder according to claim 1 or 2, wherein a side surface of the stopper portion which is not in contact with the end portion of the spring also intersects with a radial direction of the spring holder.
The spring holder according to claim 1 or 2, wherein a side surface of the stopper portion which is in contact with the end portion of the spring is formed as a flat surface.
The spring holder according to claim 1 or 2, wherein in a cross section of the stopper portion perpendicular to the axial direction, a side surface of the stopper portion that contacts the end portion of the spring is formed in a circular arc shape.
The spring holder according to claim 1 or 2, wherein, in a cross section of the stopper portion perpendicular to the axial direction, the stopper portion is formed in a triangular shape having two apexes located in the stopper surface and the other apex located radially inward of the stopper surface.
A split centering slave cylinder, characterized in that it has a spring holder according to any of claims 1 to 6.
A central split slave cylinder according to claim 7, wherein the end of the spring extends obliquely to the radial direction.
A central split slave cylinder according to claim 7, wherein the end of the spring is formed in a hemispherical shape.
The medium split secondary cylinder according to claim 7 wherein the spring retainer includes a radially extending portion that axially abuts the end portion of the spring, the stop surface extending from an outer peripheral edge of the radially extending portion toward one axial side, a radial width a of the radially extending portion, a radial height h of the stop portion, and a wire diameter d of the spring satisfying the following condition: a is more than or equal to d + h.