DE102017114325A1 - Compressor unit for motor vehicles - Google Patents

Abstract

The invention relates to a compressor unit (1) for a motor vehicle, comprising a housing (9), a crankshaft (2) rotatably mounted about an axis A, a drive element (3) and a coupling device arranged between drive element (3) and crankshaft (2) (4), wherein the drive element (3) on the crankshaft (2) is rotatably mounted and the coupling device (4) comprises a switchable friction clutch, wherein the circuit of the friction clutch friction clutch parts (11, 12, 12a, b, 27, 28, 34 , 35, 36), at least one spring element (6) and an actuating element (7) are provided. The compressor unit is characterized in that the actuating element (7) has a piston (8), wherein the piston is guided in the housing (9)

Description

The invention relates to a compressor unit for motor vehicles for generating compressed air with a coupling device, via which an air compressor can be coupled to the drive train of the motor vehicle.

By means of such a compressor unit comprising an air compressor and a storage unit, compressed air is generally kept ready for various units of the motor vehicle. These units are usually incorporated in separate compressed air circuits, these compressed air circuits must be fed with compressed air from time to time due to the compressed air consumption by the units and leaks. For example, for the brakes of a commercial vehicle on the road compressed air is required, which must be available due to the safety relevance of the brake system, with high availability, with sufficient air pressure and in sufficient quantity.

Compressed air supply systems with a coupling device have the advantage that an energetically favorable switching off the air compressor is possible by the intermediate coupling when a supply of the vehicle compressed air system is not necessary due to a sufficient pressure level in the storage system.

Like in the DE 10 2004 059 834 A1 already disclosed, an air compressor can be connected switchably to the drive train of the motor vehicle.

A Reibflächenkupplung for use in motor vehicles, z. B for switching an air compressor is in the EP2 142 818 A1 disclosed. Since the proposed Reibflächenkupplung must be installed between the drive and air compressor, such a coupling is only used if the installation situation allows.

One of the objects of the invention is to propose a compressor unit which comprises a friction clutch unit which is designed such that there is no significant change in the installation position of the compressor unit. Another object is to propose a method for controlling the friction clutch unit.

According to the invention this object is achieved with a compressor unit according to claim 1 and a method according to claim 12. Further advantageous embodiments and preferred variants of the solution are described in the subclaims dependent thereon.

The inventively proposed compressor unit for a motor vehicle comprises a housing, a rotatably mounted about an axis A crankshaft, a drive element and a coupling device. The compressor unit may have one or more compressor stages, which, as known from the prior art, may be designed as a piston compressor, wherein the drive element is rotatably mounted on the crankshaft and the coupling device comprises a switchable friction clutch, wherein the circuit of the friction clutch, friction clutch parts, at least a spring element ( 6 ) and an actuator ( 7 ) are provided.

The compressor unit is characterized in that the actuating element has a piston, wherein the piston is guided in the housing.

The housing may be the crankshaft housing or a crankshaft housing flange that closes the crankshaft housing. The piston can be designed as a pneumatic piston and pneumatically controlled.

A friction clutch in the sense of the invention is understood to mean a clutch which has at least one frictional contact formed by the coupling parts, the frictional surfaces touching the coupling parts in the frictional position of the clutch in this frictional contact. The coupling parts are also referred to as synchronizer rings, which may be conical, for example.

The plane or even surface in which the friction surfaces of the components touch can generally also be referred to as a friction plane, wherein the friction plane is understood to mean an annular surface or, for example, also a cone plow surfaces.

An advantageous friction clutch is constructed such that the friction clutch parts by means of the spring element in a first switching position, the closed position, is switched, in which a torque from the drive element on the friction clutch on the crankshaft is transferable. This ensures that the friction clutch parts are closed in the idle state, so that is started with the start of the engine of the motor vehicle directly to the compressed air generation without having to switch from one shift position to the other.

The actuating element can be made annular overall, but optionally also a plurality of segment-like actuating elements can be distributed over the circumference.

In order to achieve the switchability of the friction clutch, it can be provided that at least one inner part of the. By means of the actuating element Friction clutch parts on the crankshaft along the axis A is movable, wherein between the inner part and the crankshaft, a rotationally fixed connection is provided.

Furthermore, it can be provided on the inner part of a force transmission surface, which is designed as a sliding bearing surface and against which a sliding bearing surface area of the actuating element along the axis A is movable.

In an advantageous embodiment, the friction clutch may comprise an outer part and an inner part, wherein between the outer part and the inner part at least three conical friction surfaces are arranged such that the friction surfaces can be brought into frictional contact by means of the spring element.

Frictional surfaces or friction planes are to be understood as meaning a pairing of two surfaces which can be brought into contact with one another via which a frictional torque can be transmitted.

In a first advantageous embodiment it can be provided that between the outer part and the inner part of the friction clutch, two movable ring elements are arranged with inner or outer friction linings, said ring elements can be displaced independently of each other in the axial direction.

In particular, the ring elements may be arranged such that with progressive wear of the friction linings change their relative position to the outer part and inner part such that the frictional forces in the Reibkontakten remain substantially constant, provided that the spring elements are designed such that the spring force remains constant over the displacement , Due to the conical design of the friction surfaces, the movable ring elements are axially displaced during the shooting of the coupling device into the position that the frictional forces in the friction contacts come into equilibrium.

In a preferred embodiment, a respective ring element is assigned to the outer part or the inner part. Thus, the ring elements may each have a torque coupling with the inner part or the outer part. Furthermore, it can be provided that the outer ring element are coupled to the inner part and the inner ring element to the outer part.

In a second advantageous embodiment, the outer part and the inner part can mesh in the axial direction in a labyrinth-like manner and the friction surfaces can be arranged in the radial gaps.

The space requirement in the axial direction is very low for both versions. This also makes it possible to replace a standard compressor unit with a compressor unit with a clutch.

In order to further improve the alignment of the friction surfaces and to shorten the run-in times, it is further proposed to design the outer part and / or the inner part in two parts, one Keilringabschnitt is connected via a spring element with a support portion of the outer part and / or the inner part.

Furthermore, a support spring can be provided, by means of which the wedge ring portion of the outer part is supported in the axial direction.

In all embodiments, the crankshaft may have a central oil passage through which the friction clutch parts, parallel to the bearing points on the crankshaft, can be supplied with oil. In order to further improve the oil supply in the friction contacts, the oil passage can be continued from the crankshaft between the inner parts or through a channel in the inner part to at least one frictional contact.

The invention further comprises a method for controlling a compressor unit with coupling device for a vehicle, comprising a control unit, a drive motor, a compressed air reservoir and a compressor unit, according to one of the embodiments described.

The method is characterized in that a pressure sensor is provided in the pressure accumulator, by means of which the pressure in the compressed air reservoir is measured when initiating a starting operation of the drive motor and when exceeding a pressure limit in a first step, a signal is generated by the controller, through which the friction clutch parts of the Closed position is switched to the open position and the starting process of the drive motor is initiated in a subsequent step.

This method achieves that the torque required to start the engine can be reduced if the compressed air system has sufficient air supply / pressure. This is particularly advantageous for the start / stop automatic in modern vehicles.

Furthermore, the compressor unit may have a cylinder head with means for switching to an idling operation, wherein the means are designed such that the compression process can be switched from a filling circuit to an idling circuit. Such cylinder heads with means for switching to an idle circuit are well known in the art. in the Essentially valves are controlled such that the compressor can no longer generate compressed air, whereby the required drive power is greatly reduced.

Furthermore, it is proposed that the switchover from the no-load circuit into the filling circuit during the start-up process can be carried out with a time delay for switching the coupling device.

During operation of the compressor unit can further be provided that when reaching an upper pressure limit in the compressed air reservoir only a circuit in the idle mode and delayed release the coupling parts are switched to the open position.

Further features of the compressor unit according to the invention and further advantages of the invention will become apparent from the following description of preferred embodiments with reference to the drawings.

The invention will be explained in more detail with reference to drawings.

In these show:

1 the connection flange side of a compressor unit with a first coupling design

2a , b Clutch worn with unconsolidated lining / coupling

3 the connection flange side of a compressor unit with a second coupling design

4 and 5 Variants of the second clutch version

6 third variant of the coupling design

1 shows the connection flange side of a compressor unit 1 for a motor vehicle with a clutch according to a first coupling design. Not shown is the reciprocating compressor with the cylinder head. This may be a single or multi-piston compressor as known from the prior art. The illustrated compressor housing part 9 may be a part of the crankcase or a crankcase flange cover. For installation in the drive train of a motor vehicle, the illustrated section of the compressor unit is inserted into a corresponding opening of the transmission and screwed thereto.

When installed, the drive element 3 , here a gear, driven by a corresponding gear wheel. All parts shown thus come into contact with the transmission oil and are thus supplied via the transmission lubricating oil circuit with lubricant.

The crankshaft 2 is in the compressor housing 9 stored. The oil supply to the bearings as well as the coupling parts via the oil channels 13a , b, c. The oil can be taken beispielswese the gear lubrication circuit.

The gear 3 is about the plain bearings 18 on the crankshaft 2 or on the support ring 14 rotatably mounted. The sleeve-shaped driver 10 is with the gear 3 rotatably coupled and has in this embodiment an internal toothing, in which the external toothing of the outer part 11 intervenes. so that there is a non-rotatable connection here as well. Between the crankshaft 2 and the inside parts 12 is a sliding connection 16a provided so that the inner part is mounted axially verschiebar.

The actuator 7 consists of a part with two functional areas. So the first functional area is through the cylinder 8th formed in the compressor housing 9 is stored, so that a pneumatic cylinder is formed. The second functional area is a pusher with a sliding surface area 22 ,

In 1 the friction clutch is in the closed position, in which the inner part 12 through the spring 6 along the crankshaft 2 in the direction of the outer part 11 is moved, that the friction surfaces of the outer part 11 , the ring elements 27 . 28 and the inside parts 12 are pressed against each other or are engaged. In this position, a torque from the gear 3 over the coupling device 4 on the crankshaft 2 be transmitted.

The friction surfaces or the friction planes 15 are conical, wherein the angle of the cone 9 to 11 °, preferably 10 °, can be. The ring elements 27 . 28 are loose between the inner part 12 and outer part 11 arranged, wherein loose in the sense of the invention means that the ring elements 27 . 28 freely movable in the axial direction and in the direction of rotation in each case a ring element 27 . 28 rotatably with the inner part 12 or taker 10 or outer part 11 is coupled. The ring elements 27 . 28 are independently displaceable in the axial direction.

In this case, the ring elements 27 . 28 and the spring element 6 be arranged and designed so that, as the wear of the friction linings, this their relative position to the outer part 11 and to the inner part 12 change so that the transferable frictional forces in the friction planes 15 remain essentially constant.

In the 2a and 2 B Two situations are shown to illustrate the coupling function. Once with new and once with worn friction linings. As the wear progresses, the distances become 29a , b is always smaller or the relative positions of the ring elements 27 . 28 to the inner part 12 or outer part 11 vary. The opposing friction linings can be made of different materials, so a friction lining can also be brought into contact with the metal surface of a coupling part.

For decoupling the coupling device is the actuating element 7 intended. Will the cylinder 8th pressurized with air, the actuator moves 7 in a first step axially against the inner part 12 until the parts are in the contact plane 22 touch. The contact level 22 in which the sliding surface areas 23a , b, is designed as a sliding bearing, so that the actuator 7 is decoupled from the rotational movement of the coupling device. In a second step, with selectively rotating crankshaft, the rotatably mounted on the crankshaft inner part 12 moved axially. The friction surfaces 15 dissolve from each other. Here is the sliding path of the parts 12 . 27 and 28 designed such that it is ensured that all friction surfaces are spaced from each other.

To engage the compressed air is applied to the cylinder 8th interrupted, leaving the spring 6 the inner part 12 along the sliding connection 16a on the crankshaft 2 moves axially. The spring is supported against the support ring 14 The spring force presses the conical friction surfaces against the outer part 11 , from which the force over the circlip 31 into the taker 10 is initiated.

3 shows the connection flange side of a compressor unit 1 for a motor vehicle with a clutch according to a second coupling design.

As in the first embodiment, the outer part 11 in the driver 10 rotatably and axially fixed installed. Furthermore, there are three friction surfaces or friction planes 15 provided, which are arranged on different radial areas. The inner part 12 and the outer part 11 engage here labyrinth-like into each other and in each axially aligned gap is a conical frictional plane 15 arranged. Moves the inner part 11 in spring force direction are the friction surfaces 15 pressed against each other and a torque is transferable.

Compared to the StdT build both versions much more compact and the transmissible moments are much larger.

To optimize lubrication, an oil channel leads directly into the lower part of the innermost cone gap, so that the oil is guided by the centrifugal force through the following cone gaps, ie through the labyrinth gap.

4 and 5 show further variants of the second coupling design. This is essentially about improving the run-in behavior by the wedge ring sections 21a , b elastic with the support sections 24a , b are coupled. This has created a way to compensate for small tolerance errors.

The arrangement of the elastic elements 20 a, b is shown only as an example, as well as the optional support spring 25 through which also the outer part 11 axially flexible held in position.

In 6 a third embodiment of the coupling design is shown. The basic structure with respect to the crankshaft 2 , the case 9 , including the bearing of the piston 8th , of the actuating element 7 with the contact surface 22 , is the same as in the 1 and 5 shown.

The coupling device 4 consists of the three coupling parts 34 . 35 and 36 , where also on the gear 3 a friction surface 15 is arranged. The torque transmission takes place in this embodiment of the gear 3 over the three rubbing levels 15 on the carrier part 41 , which rotatably and positionally fixed on the crankshaft 2 is attached.

For positive power transmission, the second coupling part 35 a gearing on that in a gearing 37 in the gear 3 intervenes. The first coupling part 34 has two teeth. Once it is with the third coupling part 36 toothed and on the other engages a further toothing in a toothing 38 on the support part 41 one.

The spring element 6 is here designed as a plate spring, which is against the repository 39a , B and in the unactuated state, a force on the sliding sleeve 33 on the coupling element 34 exerts, so that the friction linings or friction surfaces in the friction planes 15 be pressed against each other. In the illustrated position, the coupling device 4 in the closed position.

Will the actuator 7 operated, so by the piston, not shown 8th moved along the axis A, the spring element 6 in the area of the contact level 22 pressed to the left. This bends the spring 6 to the re-camp 39a , b such that the spring duck on the sliding sleeve 33 eliminated.

The sliding sleeve moves to the right, so that no force acts on the coupling parts or the friction planes. The clutch can no longer transmit power.

This construction offers the advantage that the coupling parts 34 . 35 . 36 are essentially standard components, whereby the coupling is relatively inexpensive.

The method of controlling the compressor unit 1 is essentially based on a sensor on the pressure accumulator, by means of which the air pressure in the memory can be measured. During a long standstill, the pressure can drop below a limit, which means that the connected compressed air circuits can no longer be supplied with compressed air. In this case, the coupling is due to the spring force of the spring 6 closed, so that when initiating a startup of the drive motor can not be switched to the open position and the engine is started together with the compressor.

If, in contrast, a pressure limit value is exceeded, the coupling unit can be moved into an open position, so that the compressor unit is decoupled and the starting process is less energy-consuming, since the compressor does not have to be driven with it.

The method of control may additionally provide that the compressor is switched to a no-load operation via a valve in the cylinder head, if this makes sense for energy efficiency or the operating strategy.

In this case, the switchover from the no-load circuit into the filling circuit, during the starting process, can take place with a time delay for switching the coupling device.

It is further provided that during operation of the compressor unit, upon reaching an upper pressure limit in the compressed air reservoir, first a circuit in the idle circuit takes place and delayed the Reibkupplungsteile ( 4 ) is switched to the open position.

LIST OF REFERENCE NUMBERS

1

 compressor unit

2

 crankshaft

3

 Drive element or gear

4

 coupling device

5

 actuator

6

 spring element

7

 jig

8th

 piston

9

 compressor housing

10

 takeaway

11

 Outer part with friction surfaces

12, a, b

 Inner part (s) with friction surfaces

13a, b, c

 oil passage

14

 support ring

15

 Friction surfaces / friction plane

16a, b

 slide connection

17

 poetry

18

 bearings

19

 screw

20a, b

 spring element

21a, b

 Wedge ring section

22

 Contact level

23a, b

 sliding surface

24a, b

 support section

25

 support spring

26

crankshaft bearing

27, 28

 ring element

29a, b

 distance mass

30

attack

31

 circlip

32

 backstop

33

sliding sleeve

34, 35, 36

 coupling parts

37, 38

gearing

39a, b

 abutment

40

support ring

41

support part

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102004059834 A1 [0004]
• EP 2142818 A1 [0005]

Claims (15)

Compressor unit ( 1 ) for a motor vehicle, comprising a compressor housing ( 9 ), a rotatably mounted about an axis A crankshaft ( 2 ), a drive element ( 3 ) and one between drive element ( 3 ) and crankshaft ( 2 ) arranged coupling device ( 4 ), wherein the drive element ( 3 ) on the crankshaft ( 2 ) is rotatably mounted and the coupling device ( 4 ) comprises a switchable friction clutch, wherein for switching the friction clutch friction clutch parts ( 11 . 12 . 27 . 28 . 34 . 35 . 36 ), at least one spring element ( 6 ) and an actuator ( 7 ) are provided, characterized in that the actuating element ( 7 ) a piston ( 8th ), wherein the piston in the compressor housing ( 9 ) is guided. Compressor unit ( 1 ) according to claim 1, characterized in that the friction coupling parts ( 11 . 12 ,, 27 . 28 . 34 . 35 . 36 ) by means of the spring element ( 6 ) in a first switching position, the closed position, is switchable, in which a torque from the drive element ( 3 ) via the friction clutch parts ( 11 . 12 ,, 27 . 28 . 34 . 35 . 36 ) on the crankshaft ( 2 ) is transferable. Compressor unit ( 1 ) according to claim 1, characterized in that by means of the actuating element ( 7 ) at least one inner part ( 12 ,) of the friction clutch unit ( 11 . 12 27 . 28 ) on the crankshaft ( 2 ) is movable along the axis A in the axial direction, wherein between inner part ( 12 ,) and crankshaft ( 2 ) A rotationally fixed connection is provided. Compressor unit ( 1 ) according to claim 3, characterized in that on the inner part ( 12 , a force transmission surface is provided, which serves as an axial sliding bearing ( 22 ) and against which a sliding bearing surface area ( 23 ) of the actuating element ( 7 ) is movable. Compressor unit ( 1 ) according to claim 1, characterized in that the friction coupling parts ( 11 . 12 ,) an outer part ( 11 ) and an inner part ( 12 ), wherein between the outer part ( 11 ) and the inner part ( 12 ) at least three conical friction surfaces ( 15 ) are arranged such that the friction surfaces ( 15 ) by means of the spring element ( 6 ) are engageable. Compressor unit ( 1 ) according to claim 5, characterized in that between the Reibkupplungsteilen ( 11 . 12 ,) two movable ring elements ( 27 . 28 ), with internal and external friction linings are arranged. Compressor unit ( 1 ) according to claim 6, characterized in that the ring elements ( 27 . 28 ) are independently displaceable in the axial direction. Compressor unit ( 1 ) According to claim 7, characterized in that the ring elements ( 27 . 28 ) are arranged such that, with progressive wear of the friction linings, these their relative position to the outer part ( 11 ) and to the inner part ( 12 ) such that the frictional forces in the friction planes ( 15 ) remain substantially constant. Compressor unit ( 1 ) according to claim 5, characterized in that the outer part ( 11 ) and the inner part ( 12 ) mesh in the axial direction in a labyrinth-like manner and the friction planes ( 15 ) are arranged in the radial gaps. Compressor unit ( 1 ) according to claim 9, characterized in that the outer part ( 11 ) and / or the inner part ( 12 ) are made in two parts, each with a tapered ring section ( 21a , b) via a spring element ( 20a , b) with a carrier section ( 24a , b) the outer part ( 11 ) and / or the inner part is connected. Compressor unit ( 1 ) according to claim 10, characterized in that a support spring ( 25 ) is provided, by means of which the wedge ring section ( 21a ) of the outer part ( 11 ) is supported in the axial direction. Method for controlling a compressor unit ( 1 ) for a vehicle with a control unit, a drive motor, a compressed air reservoir and a compressor unit according to one of claims 1 to 11, characterized in that in the pressure accumulator, a pressure sensor is provided, by means of which the pressure in the compressed air reservoir is measured when initiating a start operation of the drive motor and when a pressure limit value is exceeded in a first step, a signal is generated by the controller, by which the friction clutch parts ( 11 . 12 ,, 27 . 28 . 34 . 35 . 36 ) is switched from the closed position to the open position and in a subsequent step, the starting operation of the drive motor is initiated. Method according to claim 12, characterized in that the compressor unit ( 1 ) comprises a cylinder head with means for switching to an idling operation, wherein the means are designed such that the compression process can be switched over, from a filling circuit into an idling circuit. A method according to claim 13, characterized in that the switchover from the idle circuit into the filling circuit during the startup takes place with a time delay for switching the coupling device. Method according to one of claims 13 or 14, characterized in that during operation of the compressor unit when reaching an upper pressure limit value in the compressed air reservoir is first a circuit in the idle circuit and delayed release the Reibkupplungsteile ( 11 . 12 . 12a , b, 27 . 28 . 34 . 35 . 36 ) is switched to the open position.

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