WO2006068491A1

WO2006068491A1 - Clutch actuator

Info

Publication number: WO2006068491A1
Application number: PCT/NO2005/000463
Authority: WO
Inventors: Sven Elfverson; Sven BJØRKGÅRD; Morten Berger Gunnerud
Original assignee: Kongsberg Automotive As
Priority date: 2004-12-20
Filing date: 2005-12-15
Publication date: 2006-06-29
Also published as: SE0403121L; SE528218C2; SE0403121D0

Abstract

A clutch device for a vehicle comprising a pressure plate and a friction plate, which by means of the pressure plate is forced into abutment against the flywheel. A release bearing is connected by suitable means to the pressure plat, and the release bearing is attached to a clutch actuator for engaging and disengaging the clutch. The clutch actuator is provided with a through passage for the gearbox's ingoing shaft and several piston devices, each positioned at a distance from the through passage. The clutch device is characterised in that the through passage (4) is provided with a lead-in passage (lla) extending from the outside of the clutch actuator to the through passage. The lead-in passage is adapted for inserting the gearbox's ingoing shaft (2) for mounting the clutch actuator and withdrawing the gearbox' s ingoing shaft for dismantling the clutch actuator.

Description

Clutch actuator

The present invention relates to a clutch device for vehicles.

In many vehicles today a clutch actuator is employed in the form of a slave cylinder, which is arranged coaxially round the gearbox's ingoing shaft and mounted between the clutch and the gearbox. In this connection, we refer to DE 2923487 which discloses an example of such a central actuator.

There are several advantages of using a central slave instead of an external clutch actuator affixed outside the clutch housing. The central slave has greater efficiency, there is no need for a lever and the central slave consists of fewer parts.

If it is necessary to replace the central slave or carry out maintenance that requires the central slave to be dismantled, this entails the need to divide motor and gearbox in order to be able to release the central slave from the gearbox's ingoing shaft. Compared to an externally located clutch actuator, servicing the central slave is extremely time-consuming and therefore also costly. For example, a workshop can take a long time to replace a central slave in a lorry, while an external clutch actuator can be replaced in a relatively short time.

In light of this, it is an object of the present invention to provide a solution where a clutch actuator is arranged in such a manner that it can easily be dismantled and mounted round the gearbox's ingoing shaft. This is achieved by the invention as indicated in the independent patent claim 1. Further embodiments of the invention are indicated in the following dependent patent claims.

The clutch device according to the invention comprises a pressure plate and a friction plate, which by means of the pressure plate is forced into abutment against the flywheel and a release bearing which is connected by suitable means to the pressure plate, for example by a spring device. In this connection we refer to patents SE 548387, FR 2653195 and DE 4226627 which disclose different solutions for the connection between the release bearing and the friction plate. The release bearing, moreover, is attached to a clutch actuator for engaging and disengaging the clutch. The clutch actuator is provided with a through passage for the gearbox's ingoing shaft and several piston devices, each positioned at a distance from the through passage.

We refer here to US 6,116,399 in which a clutch actuator is disclosed comprising several piston devices attached to an annular plate. The annular plate is arranged round the gearbox's ingoing shaft, with the result that piston devices spaced at equal distances apart are located at an equal distance from the gearbox's ingoing shaft. In US 6,116,399 no solution is indicated for simple mounting and dismantling of the clutch actuator. The clutch actuator according to the invention is characterised in that the through passage is provided with a lead-in passage extending from the outside of the clutch actuator into the through passage. The lead-in passage is adapted for inserting the gearbox's ingoing shaft for mounting the clutch actuator and withdrawing the gearbox's ingoing shaft for dismantling the clutch actuator. The insertion and withdrawal of the gearbox's ingoing shaft are preferably implemented by moving the clutch actuator sideways in towards the gearbox's ingoing shaft, whereby the gearbox's ingoing shaft is admitted and inserted in the lead-in passage for location in the through passage. The gearbox's ingoing shaft is preferably inserted in the lead-in passage in a direction substantially coincident with or parallel to the ingoing shaft's radial direction, i.e. in a direction that is oriented perpendicularly to the ingoing shaft's axial direction. The design and dimensions of the lead-in passage conform to the diameter of the ingoing shaft, thus enabling the ingoing shaft to be passed unimpeded through the lead-in passage. Thus by designing this lead-in passage in connection with the through passage, the need is obviated for separating motor and gearbox in order to mount or dismantle the clutch actuator.

As a person skilled in the art will appreciate, the design, dimensions and location of the lead-in passage may vary in the clutch actuator depending on the gearbox's ingoing shaft and other design conditions. A preferred embodiment of the lead-in passage will be presented here, where it is defined with regard to its length, width and depth in a favourable combination. As the skilled person will understand, each of the following specifications of the length, width and depth of the lead-in passage may be combined in different ways. It should be mentioned here that the clutch actuator's axial direction and radial direction are parallel to the ingoing shaft's axial direction and radial direction respectively when the clutch actuator is mounted round the ingoing shaft.

The lead-in passage may have a length that is oriented substantially parallel to the actuator's axial direction. Furthermore, the lead-in passage may have a depth that is oriented substantially parallel to the actuator's radial direction. The lead-in passage may have a width that is oriented substantially perpendicularly to the length and depth. The width will be adapted to the ingoing shaft's diameter, thus making it possible to perform a smooth and easy insertion in the lead-in passage.

The lead-in passage will preferably be open all the way through viewed in its longitudinal direction, for example by the lead-in passage terminating in two end openings at the end of its length.

In order to ensure that the clutch actuator is correctly located in the clutch device and to facilitate insertion and withdrawal, a guide track or guide portion may be provided in the clutch housing. In addition, the guide track/guide portion will absorb axial forces during actuation. In known solutions these forces are transferred to the clutch housing's rear wall. In a preferred embodiment where the clutch housing is provided with a protruding guide portion, the latter will be adapted for interaction with a guide track provided in the clutch actuator. As a skilled person will understand, the clutch housing or other suitable components included in the clutch device and the clutch actuator may be arranged in different ways in order to achieve a satisfactory insertion or withdrawal of the clutch actuator.

In an embodiment of the invention the number of piston devices is three, but this number may, of course, be varied depending on the conditions that have to be met by the clutch device. The piston devices will preferably be located in a circle round the through passage.

For communication of pressure medium to/from and between the piston devices, channels are preferably provided between the piston devices and at least one channel between at least one of the piston devices and the outside of the clutch actuator.

The clutch device according to the invention may be a pushing clutch or a pulling clutch. Where the clutch device is a pulling clutch, the release bearing and the clutch actuator must be arranged so that the clutch actuator engages with the release bearing in order to exert a pulling force on the release bearing. The release bearing may therefore be provided with a protruding attachment portion or an attachment portion suitable for engagement with an interacting profile in the clutch actuator.

According to a preferred embodiment of the clutch device, the clutch actuator comprises a stationary actuator part and a movable actuator part. In this case the through passage and the lead-in passage will preferably be provided in the movable actuator part. This will become clearer in the following explanation which will be presented in connection with the figures.

The invention will now be explained by means of an example illustrated in the attached drawings, in which

Fig. 1 illustrates a section through a clutch device according to the invention viewed from in front.

Fig. 2 illustrates a section through a clutch device according to the invention viewed from in front.

Fig. 3 illustrates a longitudinal section of a pulling clutch device according to the invention.

Fig. 4 illustrates a longitudinal section of a pushing clutch device according to the invention. In figure 1 the clutch actuator 1 is shown mounted in operating condition round the gearbox's ingoing shaft 2. As illustrated in figure 1 the clutch actuator comprises a first stationary actuator part 9 attached to a guide track 6 in the clutch device's housing 7 (as illustrated in greater detail in figures 3 and 4). The clutch actuator 1 further comprises a movable actuator part 5 provided with a through passage 4 in which the ingoing shaft 2 is received. The through passage 4 is open all the way through in a direction coincident with the clutch actuator's axial direction.

The clutch actuator's 1 axial direction and radial direction are parallel to the ingoing shaft's 2 axial direction and radial direction respectively when the clutch actuator 1 is mounted round the ingoing shaft 2. Stationary here means that the actuator part 9 is secured to the housing 7, while the actuator part 5 is moved in the clutch actuator's 1 axial direction for engaging or disengaging the clutch device. It can be seen from figure 1 that the clutch actuator 1 is provided with three piston devices 3 and that the movable actuator part 5 is designed so that the three piston devices 3 are positioned in a circle round the through passage 4. The seals 8 prevent dust from infiltrating the actuator. The stationary actuator part 9 is depicted with a termination portion 10 that abuts against the clutch housing's 7 outer surface 7a. It is provided with channel portions 10a in the termination portion 10. These channel portions 10a can be used in connection with fluid transfer to the piston devices 3.

In figure 1 it can be seen that a lead-in passage 11 is provided extending from the movable actuator part's 5 outer surface radially inwards towards the through passage 4. The lead-in passage 11 has a length extending parallel to the clutch actuator's axial direction and terminating in a longitudinal opening 1 Ia in the outer surface 5a. The longitudinal opening 11a and the lead-in passage 11 have a width b that is adapted depending on the ingoing shaft's 2 diameter. The lead-in passage 11 terminates in two end openings, each defined by the lead-in passage's width b and depth d. The lead-in passage 11 is therefore also open all the way through in its longitudinal direction. When the clutch actuator 1 is mounted in the clutch device, the clutch actuator 1 is moved in towards the ingoing shaft 2 in a direction substantially coincident with the ingoing shaft's 2 radial direction. By means of this movement of the clutch actuator 1 the ingoing shaft 2 is inserted through the opening 11a and through the lead-in passage 11, with portions of the ingoing shaft 2 protruding from the lead-in passage's 11 end openings, until the ingoing shaft 2 is located in the correct position in the through passage 4. With this solution the object is achieved that the clutch actuator 1 can be mounted and dismantled without the need to dismantle motor and gearbox, as is the case in today's solutions.

The clutch housing 7 is provided with a guide portion 6 that is suitable for engaging with a guide track 9a (not shown in figure 1, see figure 2), which is provided in the actuator part 9. The guide portion 6 and the guide track 9a permit the clutch actuator 1 to be easily pushed into the correct position, and when the clutch actuator is dismantled, it is withdrawn by sliding between the guide portion 6 and the guide track 9a. The guide track 9a and the guide portion 6 are designed so as to enable axial actuating forces to be absorbed here.

Figure 2 is a rough sketch of the clutch actuator 1 depicted with channels 12a for fluid transfer between the individual piston devices and a channel 12b for fluid communication with equipment outside the clutch actuator.

Figure 3 illustrates the clutch actuator mounted in a pulling clutch. Here the clutch actuator is illustrated by the stationary actuator part 9, the movable actuator part 5 and the piston device 3. The guide portion 6 and the guide track 9a are clearly illustrated in this figure. The clutch actuator is shown with the piston device 3 in a pressurised condition. The clutch device's friction plate 12, which is illustrated here by a clutch disc, is therefore not engaged with a flywheel 13 and no torque is transferred to the gearbox's ingoing shaft 2. It can be seen in figure 3 that the clutch disc is attached to a pressure plate 14, and a spring device 15 preferably in the form of a sun spring abuts against the pressure plate's 14 abutment portion 14a. The end of the spring device 15 is mounted on the clutch cover, thus enabling the spring device 15 to tilt with the abutment portion 14a as tilting point. The spring device 15 is attached to a release bearing 16. The release bearing 16 is provided with a protruding attachment portion 17 suitable for engagement in a groove 18 in the movable actuator part 5.

Figure 4 illustrates the clutch actuator mounted in a pushing clutch. This clutch device comprises the same components as the embodiment in figure 3, and the same reference numerals are therefore employed as in figure 3. The clutch actuator is shown with the piston device 3 in a non-pressurised condition. The clutch device's friction plate 12 is therefore engaged with the flywheel 13 and a torque is transferred to the gearbox's ingoing shaft 2.

Claims

1. A clutch device for a vehicle comprising a pressure plate and a friction plate, which by means of the pressure plate is forced into abutment against the flywheel, a release bearing which is connected by suitable means to the pressure plate, and the release bearing is attached to a clutch actuator for engaging and disengaging the clutch, where the clutch actuator is provided with a through passage for the gearbox's ingoing shaft and several piston devices, each positioned at a distance from the through passage, characterised in that the through passage is provided with a lead-in passage extending from the outside of the clutch actuator to the through passage, and that the lead-in passage is adapted for inserting the gearbox's ingoing shaft for mounting the clutch actuator and withdrawing the gearbox's ingoing shaft for dismantling the clutch actuator.

2. A clutch device according to claim 1, characterised in that the gearbox's ingoing shaft is inserted in the lead-in passage in a direction substantially coincident with or parallel to the ingoing shaft's radial direction.

3. A clutch device according to claim 1 or claim 2, characterised in that the lead-in passage has

- a length that is oriented substantially parallel to the actuator's axial direction, and/or

- a depth that is oriented substantially parallel to the actuator's radial direction, and/or

- a width that is oriented substantially perpendicularly to the length and depth, the width being adapted to the ingoing shaft's diameter.

4. A clutch device according to one of the preceding claims, characterised in that the lead-in passage is designed open all the way through viewed in its longitudinal direction, and that at the end of its length the lead-in passage preferably terminates in two end openings.

5. A clutch device according to one of the preceding claims, characterised in that the clutch device also comprises a clutch housing provided with a guide track or guide portion for positioning the clutch actuator.

6. A clutch device according to one of the preceding claims, characterised in that channels are provided between the piston devices and at least one channel between at least one of the piston devices and the outside of the clutch actuator. A clutch device according to one of the preceding claims, characterised in that the release bearing is provided with a protruding attachment portion or an attachment track suitable for engagement with an interacting profile in the clutch actuator.