DE3441557A1 - FRICTION CLUTCH - Google Patents

Description

Dr. Dieter Weber Klaus Seiffert Patent Attorney

Dipl.-Chem. Dr. Dieter Weber · DipL-Phys. Klaus Seiffert Poetfach 6145-6200 Wiesbaden

German Patent Office
Zweibrückenstrasse 12th

8000 Munich 2

D-6200 Wiesbaden 1

Gustav-Freytag-Straße 25 Telephone 0 6121/37 2720 + 37 2580 Telegram address: Willpateni Telex: 4-186247 Telco Gc III 06121/372111

Post check: Frankfurt / Main 67 63-602 Bank: Dresdner Bank AG, Wiesbaden, Account number 27680700 (BLZ61080060)

Date 13th NOV. 1984

We / Wh

W.H. den Ouden N.V. Fokkerstraat 1, NL-3125 BD Schiedam

Friction clutch

Priority; Dutch patent application no. 8 303 950 of November 17, 19 83

Friction clutch.

The invention relates to a friction clutch, in particular for an arrangement between an internal combustion engine and a reverse gear, which clutch comprises at least one friction ring which is axially displaceable on the axis to be coupled and which is rotatably supported by means of rolling elements against an annular disk firmly connected to the axis to be coupled, the rolling elements are mounted between inclined to a ^ nderTiegenüberliegenden end faces of the friction ring and the annular disc oblique surfaces, means to r - _t are xialen displacement of the friction ring for turning on and turning off the clutch is provided.

Such a friction clutch is described in Dutch patent specification 157,970. In this known friction clutch the means for the axial displacement of the friction ring are formed by a switch sleeve, which is extends annularly around the annular disc arranged on the axle to be driven. The shift sleeve is over theirs Outer circumference provided with a slot in which a shift fork engages, which is guided displaceably in the axial direction and can be actuated by means of a lever transmission.

Since the shift fork is only displaceable in the axial direction, are considerable, especially during the actuation of the clutch Frictional forces are generated. The actuation of the clutch also requires a considerable effort.

Attempts have been made to eliminate this disadvantage by designing the clutch hydraulically. With such a For the clutch, however, it is necessary that the used medium is under pressure during the entire switch-on time of the clutch is held. This requires a considerable amount of property, so that the efficiency of such a coupling in a smaller assets to be transferred is particularly bad.

The invention now intends to eliminate the disadvantages of the two types of clutches and provides a friction clutch for this purpose, which is characterized in that the friction ring displaceable over the axis on the one hand the inner circumference is sealed off from the axis and on the other hand at a distance from the inner circumference lying axial surface opposite the annular disc is sealed to form a closed first space between the opposing end faces of the friction ring and the washer, which space is pressure medium can be supplied to engage the clutch, while opposite the other end face of the friction ring on the Axis a locking ring is provided, which is supported in relation to the axis that it cannot move from the friction ring, which locking ring on the inner circumference with respect to the axis and with respect to the outer circumference with respect to the friction ring or an associated pressure ring is sealed so that a second closed space is formed between the end ring and the friction ring, the Pressure medium can be supplied to switch off the clutch, with channels for the on and off through the axis Discharge of pressure medium to the spaces formed by means of a stationary operating valve run and in the annular disc valve members are provided, which connect the supply and discharge channels for the pressure medium can bring about after a switchover of the clutch has taken place.

A friction ring thus essentially forms a piston of a double-acting pressure medium cylinder, so that on the piston a considerable force can be exerted without this being difficult for the operator.

The pump that takes care of the pressure medium can be driven by the input shaft of the clutch as this also applies to the already known hy-

hydraulically operated clutches is done. Immediately at the pump can then also use the service valve for the arbitrary supply of pressure medium in the stationary part of the coupling can be recorded in a specific room.

If you now in the annular disc, the valve organs described above attaches, care is taken that the medium supplied by the pump is only under the full pump pressure must come to a standstill when the clutch is actuated. Immediately after the clutch to the desired position is brought, the medium no longer needs to be under the full pump pressure and the pump becomes the medium just let it circulate. Although this of course costs some fortune, this fortune is relative to that described above hydraulically acting clutch low.

According to a preferred embodiment of the invention, the Valve organs by arranged in the annular disc, essentially Radial bores formed with a piston in each bore, which is used by a spring and / or by the Print medium to the outside against the inner circumference of one with. the friction ring co-rotating control ring pressed, in which a number of cavities corresponding to the number of pistons is provided, which are arranged such that using the constrained angular displacement that between the friction ring and the axle to be coupled when bringing the coupling into a certain desired position occurs, always one of the pistons is pushed outwards into the relevant cavity and thereby a connection between the used supply line for pressure medium and the suction side of the pump.

According to a further elaboration of the invention it can be provided that from the inner end of each piston from therein an axially extending channel is arranged, which is in a

radially extending channel continues, which ends in the piston wall at such a point that this channel from the Bore comes free in which the piston is when the piston is pressed into the associated cavity.

The design can be such that when medium is supplied to a space around the clutch in the neutral To bring position at the same time pressure medium is supplied to the axial channel of this piston, which is in the associated cavity is pressed when the clutch has reached its neutral position, while when pressure medium is supplied to the space, whereby the clutch is brought into an engaged position, at the same time medium one in the axial direction in the annular disc provided channel is supplied which opens out against the piston after the clutch in the engaged position is brought, is pushed into the associated cavity, during which movement the channel is released around the connection between this channel and the first axially and then radially extending through the piston channel.

This means that when the clutch is placed in an on position, a high I-tedium pressure is required can be, a double closure of the discharge channel is present in that the channel in which the medium is is under pressure, not directly nii'c that provided in the piston Channel is in communication but is closed by the wall of the piston and is only released when the piston moves outwards.

In order to prevent the clutch from moving from an operating position to the neutral position and then back into the same or another operating position is brought, it can be provided that when the operating valve of the clutch the neutral position is brought, the operating valve is blocked by the pressure build-up of the operating medium until

the related valve member present in the washer has ensured that the connection between the related Supply channel for pressure medium and the suction side of the pump is brought about in such a way that the pump pressure up to the circulation pressure has decreased.

In this way it is achieved that a subsequent coupling can only take place after the coupling is positive in the neutral Position has come. This will prevent damage to the clutch from switching over too suddenly, while the working pressure of the oil pump can also be limited.

Of course, it is particularly possible to switch the clutch from forward to backward, that is, to reverse it the direction of rotation of the axis to be coupled.

According to a preferred embodiment of the invention, the Blocking of the operating valve by a pin which is received as a piston in a cylinder and which passes through the pressure of the medium can be pressed so firmly into a recess in the control valve that the control valve cannot be operated.

As will be clear, the coupling described above can be used in particular to drive an axis to be coupled in opposite directions Directions are applied, with a friction ring acting as a piston on both sides of the annular disc is provided and there are a total of three valve members in the annular disc.

The invention will now be explained in more detail using an exemplary embodiment which is shown in the drawing, in which:

Fig. 1 is a longitudinal section through a double-acting coupling Enjoyment of the finding shows, with certain ones for the sake of clarity

Items are shown in a different position;

Fig. 2 shows a cross section over part of the coupling according to the line II-II in Fig. 1; and

3 shows a detailed section through the two friction rings and the annular disk located between them, roughly according to the broken one Line III-III of Fig. 1 and. In a somewhat enlarged Scale shows.

The coupling shown in the drawing comprises a fixed flange 1, against which is not shown further Way the housing 2 is attached. Through the flange

1 and the housing 2 is driven by means of the bearings 3 and 4 Axis 5 supports on which the gears 6 and 7 are attached. In the case of the bearing 4, the housing is through a Cover 8 completed. Through the flange 1 and the housing

2 becomes the axle 11 to be coupled by means of bearings 9 and 10 supported by means of the flange plate 12 with the to be driven Item can be connected. The housing is around the protruding part of the flange plate 12 by means of of the ring 13 sealed.

On the axis 11 to be coupled are by means of the bearings 14 and the gears 16 and 17 are rotatably arranged. The gear 16 stands in direct engagement with the gear 6 on the driven axle, while the gear 17 has a not shown, rotatably supported by the housing gear is in engagement with the gear 7 on the driven axle.

When the driven shaft 5 rotates in the direction of arrow P, the driven shaft 11 will turn in the same Rotate direction when the axle is firmly connected to the gear 17, and in the opposite direction when the axle 11 is connected to the gear 16.

For coupling the axle 11 to one of the gears 16 or 17 is on the axis 11, the washer 18 with both sides of the same the friction rings 19 and 20 provided which are slidable with respect to the axis 11 and the annular disk 18 are and means O-rings make a sealing contact with the axle and the washer. This is between the ring washer 18 and the friction rings 19 and 20 receive the pressure medium spaces 21 and 22, respectively.

On the side of the friction rings 19 and 20 facing away from the annular disk 18, the pressure rings 23 and 24, respectively, rest on the other side rest against the plate packs 25 and 26 again. The lamellae pack 25 comprises a number of lamellae, alternately with the pressure ring 24 and with the gear 16 are in connection, so that when the lamellae are pressed against each other, a connection between the gear 16 and the axis 11 to be coupled can be brought about. The same can be said of that Disk pack 26 can be said.

At the pressure rings 23 and 24 are the locking rings 27 and 28, which are sealed against the associated pressure rings and against the axis 11 by means of O-rings. In order to prevent the end rings 27 and 28 from being displaced in one direction, they rest on the axis 11 Collar 29 or 30. For the assembly, however, these collars will not form a whole with the axle, but for example can be obtained by pushing sleeves on the axis. The ring disk 18 also does not need a whole to form the axis.

In the manner indicated, pressure medium spaces are created between the friction rings 19 and 20 and the end rings 27 and 18, respectively 31 and 32 respectively.

Between the annular disk 18 and the friction rings 19 and 20 are the balls 33 and 34, which are in the manner described in the above-mentioned Dutch patent with

not indicated in more detail, facing each other in the ring disc 18 and the friction rings 19 and 20 arranged bevels The surfaces interact after the coupling of the axle. 11 to maintain the clutch.

In the annular disk 18 there are also three bores 35, 36, 37 in which the pistons 28 or 39 and 40 are located, which are each pressed outwards by means of a spring 41, which is received for the most part in an axial channel 42 in the relevant piston, which channel at the end of the piston runs out into a radial channel 43 which, in the interior position of the piston, passes through the wall of the bore is closed in the annular disk 18.

The somewhat rounded ends of pistons 38-40 cooperate with a control ring 44, which is held in place opposite the annular disk 18 by pins 45, arranged in the friction rings 19 and 20 but in such a way that the friction rings 19 and 20 in the axial direction are displaceable to each other.

As can be seen from Fig. 2, in the neutral position of the clutch, the piston 38 is outwardly in the cavity

46 of the control ring 44 be pushed. Furthermore, in the one coupled position, the piston 39 is in the cavity

47 and in the other engaged position the piston 40 is in the cavity 48 of the control ring 44 have come.

For the supply of pressure medium to the space 21, the channel 49 is provided in the axis 11. For feeding print media the channel 50 is provided on the space 22 and is located for the supply of pressure medium to the two spaces 31 and 32 in the axis of the channel 51. The channel 51 is by means of a branch 52 in direct connection with the bore 35,

in which the piston 38 is located. Extend in the axial direction the channels 53 and 54 to or the bores 36 and 37 through the annular disk 18. Channel 53 is running toward the space 21 and the channel 54 toward the space 22, so that actually in FIG. 2 the channel 54 is in front of the surface of the Drawing lies. In the position of the piston 39 and 40 shown in Fig. 2, there is no open connection between the Channels 53,54 and the associated bores 36 and 37, however, such a connection arises if upon rotation the annular disk 18 of the piston 39 or the piston 40 falls into the relevant cavity 47 or 48.

The supply of pressure medium to the channels 4, 9, 50 and 51 is regulated by means of an operating valve 55, which is equipped with a continuous channel 56 is provided, which is always connected to the press connection 57 of the pump 58, dor in a Recess 59 is received in the flange 1 and on the other hand is sealed by means of the plate 60 and directly by means of the driven axle 5 is driven.

In a bore 61 in the flange 1 and the plate 60 is the pin 62, which is also in the control valve 55 provided recesses 63 can come into attack when the bore 61 is under oil in a manner not shown Pressure is applied. When the pressure delivered by the pump 58 is low, the pin 62 is only opened by means of a spring 64 pressed with a small force into a recess 63 of the operating valve 55, so that actuation of the valve under the Pushing away the pin 62 against the force of the spring 64 is possible.

It will be clear that between the channels running down from the service valve and those provided in the rotating shaft Channels must always be a connection, including in the flange 1 around the axis 11 around annular spaces

65 are provided as shown in FIG.

The effect of the friction clutch is now as follows:

In the neutral position, as shown in the drawing, from the pump 58 via the connection 57, the medium is dem Channel 56 in the service valve 55 is supplied. The medium then flows through the channel 51 to the spaces 31 and 32 and Via the branch 52 after the bore 35 and via the channels 42 and 43 in the piston 36 along the control ring 44 into the Housing of the coupling from which it can be sucked in again by the pump 58. So the pressure of the medium becomes only be very small, but the friction rings 19 and 20 are closest to the annular disk 18.

The clutch will now be switched on, e.g. by turning the operating valve 55 from the position indicated by N. off after position V. The channel 56 of the valve 55 that is connected to the discharge line 57 of the pump 58 then comes into contact with channel 49 in axis 11, which channel runs after the space 21 between the annular disk 18 and the friction ring 19. There is then no connection more between the discharge connection 57 of the pump and the suction side of it, so that the pump pressure will rise, whereby the friction ring 19 will be pushed away from the annular disc 18, so that the disk pack 25 is compressed via the pressure ring 23, whereby the rotating gear 16 is the axis 11 will take away. The balls 33 then begin in the known manner with the inclined run-up surfaces of the parts 18 and 19 to work together. The ring disk 18 will perform a certain angular displacement with respect to the friction ring 19, so that the piston 38 comes to lie outside the cavity 46, while the piston is in the fully coupled state 39 is received in the cavity 47. When this takes place, the piston 39 will clear the channel 53 which is connected to the space 21 connects, so that the pressure medium via the axial channel 42

and the radial channel 43 in the piston 39 after the with oil filled space within the housing 2 of the coupling can flow away. The pump 58 will then hardly need to supply any more pressure.

If one then wishes to switch off the clutch, the control valve 55 is again according to the first described Position hirTy rotated so that there is no longer a free connection between the pressure and suction side of the pump 58 is present, but medium is fed to the line 51 so that the spaces 31 and 32 are pressurized and the friction ring 19 is pushed towards its neutral position. When the ring 19 has reached this neutral position, the washer becomes 18 again assume the position shown in FIG. 2 with respect to the control ring 44.

If now the control valve 55 is indicated by A in FIG Position is rotated, pressure medium is fed to the line 50, so that the friction ring 20 of the annular disc 18 is pushed away in order to compress the disk pack 26. The outgoing axis 11 will then start moving in that direction to rotate which is opposite to that of the first case.

As already described above, there is a control valve 55 a pin 62 which is pressed with a considerable force towards the control valve 55 when the pump medium delivers under pressure. If the control valve is in position A, for example, so that the axis 11 is in a certain Direction is driven, the medium displaced by the pump can circulate freely, so that the pin 62 only through the spring 64 is pressed with a small force into a recess 63 of the operating valve 55. If now under the Pushing away the pin 62, the control valve is brought to position N, the free circulation of medium is interrupted so that the pump pressure will begin to rise and the medium supplied to the space 32 will come to be under pressure. The friction ring 20 is then after the annular disk 18

are pressed while by the delivered mediurndruck the pin 62 is pressed with a considerable force into a cavity 6 3 of the operating valve 55, whereby further Rotation of the control valve after position V is prevented. Only when the clutch has come into its free position with piston 35 received in cavity 46 as shown in Pig. 2, the pressure of the pump will be 58 remove the supplied medium so that the pin 62 is removed from the Recess 63 of the operating valve 55 can be pressed when the operating valve is brought to the V position. It is now impossible to switch the operating valve 55 directly from position A to position V or vice versa.

It will be clear that only one possible embodiment of the invention is shown in the drawing and described above and that many changes can be made without going outside the scope of the inventive concept.

Claims (6)

Claims 1. Friction clutch especially for assembly between an internal combustion engine and a reverse gear, which clutch comprises at least one friction ring which is axially displaceable on the axis to be coupled and which is rotatably supported by means of rolling elements against an annular disk firmly connected to the axis to be coupled, the rolling elements between opposing end faces of the friction ring and the annular disk inclined inclined surfaces are mounted, means are provided for axial displacement of the friction ring for switching the clutch on and off, characterized in that the friction ring (19, 20) which can be displaced via the axis (11) on the one hand at the inner circumference opposite the axis (11 ) is sealed and on the other hand is sealed at an axial surface at a distance from the inner circumference to the annular disk (18) to form a closed first space (21,22) between the opposing end faces of the friction ring (19,20) and the annular disk ( 18), which room (21 , 22) Pressure medium can be supplied to switch on the clutch, while opposite the other end face of the friction ring (19, 20) on the axis (11) a locking ring (27, 28) is provided, which is supported in this way to the axis (11) that it cannot move away from the friction ring (19, 20), which closing ring (27, 28) on the inner circumference opposite the axis (11) and on the outer circumference opposite the friction ring (19, 20) or an associated pressure ring (23,24) is sealed in such a way that a second closed space (31,32) is formed between the end ring (27,28) and the friction ring (19,20), to which pressure medium can be supplied to switch off the clutch, whereby through the axis (11) through channels (49, 50, 51) for the supply and discharge of pressure medium to the spaces (21, 22; 31, 32) run by means of a stationary operating valve (55) and valve members (35-40) are provided in the annular disk (18) which provide a connection between the supply and discharge channels (49,50,51) for the pressure medium can bring about after a switchover of the clutch has taken place. 2. Friction clutch according to claim 1, characterized in that the valve members through in the annular disc (18) provided, essentially radially extending bores (35,36,37) with a piston (38,39,40) in each bore that by a spring (41) and / or by the pressure medium used to the outside against the inner circumference a control ring (44) rotating with the friction ring (19, 20) is printed, in which one of the number of pistons (38, 39,40) corresponding number of cavities (46,47,48) is provided, which are arranged in such a way that using the limited angular displacement between the friction ring (19,20) and the axis to be coupled (11) when bringing the Coupling occurs in a certain desired position, always one of the pistons (38,39,40) outwards into the relevant Cavity (46,47,48) is pushed and thereby a connection between the used supply line (49,50,51) for the pressure medium and the suction side of the pump. 3. Friction clutch according to claim 2, characterized in that from the inner end of each piston (38,39,40) from therein an axially extending channel (42) is provided, which continues in a radially extending channel (43), which ends in the piston wall in such a place that this channel (43) is clear of the bore (35,36,37), in which the piston (38,39,40) is when the piston is pressed into the associated cavity (46,47,48). 4. Friction clutch according to claim 3, characterized in that when medium is supplied to a space (31, 32) in order to bring the clutch into the neutral position at the same time pressure medium flows into the axial channel (42) of this piston (38) which is pressed into the associated cavity (46) when the coupling has reached its neutral position, while when pressure medium is supplied to this space (21, 22), the clutch is brought into an activated position at the same time medium is fed to a channel (53,54) arranged in the axial direction in.der the annular disk (18), which against the piston (39,4U) opens out, after the clutch has been brought into the engaged position, into the associated Cavity (47,48) is pushed, during which movement of the channel (53,54) to bring about the connection between this channel (53,54) and the channel (42,43) which first runs axially and then radially through the piston (39,40) is released. 5. Friction clutch according to one of the preceding claims, characterized in that when bringing the control valve (55) of the clutch after the neutral position, the operating valve (55) is opened by the pressure build-up of the operating tion medium is blocked until the relevant, in the annular disc (18) existing valve member (35,38) for the Establishing a connection between the relevant supply channel (51,52) for pressure medium and the suction side of the Pump has taken care that the pump pressure has fallen to the circulation pressure. 6. Friction clutch according to claim 5, characterized in that the blocking of the operating valve (55) is carried out by a pin (62) which is received as a piston in a cylinder (61) and which is actuated by the pressure of the medium can be pressed so firmly into a recess (63) in the control valve (55) that the control valve cannot be operated.