DE102020133941A1 - Air suspension compressor for a vehicle - Google Patents

Abstract

The invention relates to an air suspension compressor (10) for a vehicle, preferably for a vehicle compressed air system (34), in particular for an air suspension system of a vehicle, comprising an electric drive motor (36) mounted on a rotatable motor shaft (14). It is proposed that a stroke axis (D) of a piston (18) of the air suspension compressor (10) corresponds to an axis of rotation (C) of the electric drive motor (36).In a secondary aspect, the invention relates to a compressed air system (34), in particular a compressed air spring system, of a vehicle, which has at least one aforesaid air spring compressor (10).In a further subordinate aspect, the invention relates to a vehicle which comprises a aforesaid compressed air system (34), in particular a compressed air spring system.

Description

The present invention relates to an air suspension compressor for a vehicle, preferably for a vehicle compressed air system, in particular for an air suspension system of a vehicle, comprising an electric drive motor attached to a rotatable motor shaft. The present invention further relates to a compressed air system of a vehicle and a vehicle that includes a compressed air system.

STATE OF THE ART

Various air spring compressors for vehicles are known from the prior art, in which eccentrics and connecting rods are used, so that rotational movements of drive motors can be converted into longitudinal axial movements of pistons by the eccentrics and the connecting rods. In order to achieve this conversion, the eccentrics and the connecting rods are arranged at right angles to one another. In other words, a direction of rotation of the drive shaft of the drive motor is aligned perpendicular to a direction of stroke of the piston.

A generic compressor for a motor vehicle air spring system is for example in EP 1 375 919 A1 describe. The compressor includes a cylinder, a piston of the cylinder being attached to a drive motor via a connecting rod with a longitudinal axis oriented perpendicular to the connecting rod stroke direction. A large installation space is required to arrange the compressor in the air spring system.

the DE 100 05 929 A1 further discloses a compressor with a piston compressor, wherein the compressor can be used in motor vehicle air spring systems. A piston of the piston compressor is connected to a motor shaft of an electric motor via a connecting rod, with a connecting rod stroke direction being aligned perpendicular to the motor shaft. Due to a rotational movement of the electric motor and a stroke movement of the piston, strong vibrations can be generated during operation.

In the case of the known compressors, the problem arises that the air spring compressors with the eccentric and the connecting rod are based on a relatively large housing volume and a high installation space requirement. Furthermore, a number of complex mechanical components and bearings are required.

Another disadvantage of the prior art is that a large oscillating mass can result from the rotational movements of the drive motor and the stroke movements of the piston achieved with the eccentric and the connecting rod. This generates strong vibrations and causes a high level of acoustic noise.

Proceeding from the above prior art, it is the object of the invention to propose an air spring compressor with a low structural complexity and a compact design with a small space requirement and to reduce the manufacturing costs of the air spring compressor.

Furthermore, it is the object of the invention to improve the acoustics during operation of the air spring compressor.

This object is achieved by an air suspension compressor for a vehicle having the features of claim 1, a compressed air system having the features of claim 8 and a vehicle having the features of claim 9. Advantageous developments of the invention are the subject matter of the dependent claims.

DISCLOSURE OF THE INVENTION

The invention relates to an air suspension compressor for a vehicle, preferably for a vehicle compressed air system, in particular for an air suspension system of a vehicle, comprising an electric drive motor attached to a rotatable motor shaft.

According to the invention, it is proposed that a stroke axis of a piston of the air spring compressor corresponds to an axis of rotation of the electric drive motor.

Thus, an air spring compressor is proposed in which a stroke shaft of the piston of a cylinder and a rotary shaft of the electric drive motor overlap or form a structural identity. The feature that corresponds to the stroke axis of the piston and the axis of rotation of the drive motor enables a lower housing volume of the working noise of the air spring compressor compared to a conventional air spring compressor, while the air spring compressor can also be stored in a small space and thus integrated into a vehicle.

It is also advantageous that no eccentrics and no connecting rods are required to connect the piston to the motor shaft or to the drive motor. As a result, a low oscillating mass is possible when the electric drive motor is in operation. Advantageously, by reducing the vibrations, vibrations generated by the vibrations are significantly reduced, so that noise during operation can be dampened and this can lead to an improvement in the acoustics.

It is therefore advantageous that the stroke axis of the piston is designed as a continuation of the axis of rotation of the electric drive motor. An extremely compact design with the same air output is thus made possible, with the air spring compressor according to the invention being able to be arranged in a space-restricted environment of the vehicle with tightly limited space. With this compact design, the air suspension compressor can be used in a space-saving manner in the vehicle's air suspension system.

With the air spring compressor according to the invention is also advantageously achieved that the size is reduced at the same air capacity. Furthermore, the moving mass and the quantity of parts to be produced for the air spring compressor according to the invention are correspondingly reduced and simplified.

In an advantageous development of the air spring compressor, a wobble bearing can be arranged at least on one axial end of the motor shaft, with a rotary movement of a rotor of the electric drive motor being convertible into a longitudinal axial oscillating movement along the motor shaft, and the wobble bearing preferably driving the piston. The motor shaft can be mounted so that it can rotate by means of the wobble bearing. The wobble bearing is to be designed as a one-piece element and to be rotatably mounted around the motor shaft for converting motion and force, with the wobble bearing being able to rotate at a different rotational speed compared to the motor shaft. Preferably, the wobble bearing is non-rotatable relative to the motor shaft and mounted so that it can be displaced longitudinally and axially, with a mechanical coupling element converting the rotary movement of the motor shaft into an axial movement of the wobble bearing. In other words, the speeds of rotation of the wobble bearing and the speed of rotation of the rotor of the drive motor can vary. This can advantageously be achieved in that a radial movement of the rotor can be converted into an axial movement of the motor shaft, so that a longitudinal axial stroke movement of the piston can be made possible.

In a further advantageous development, the wobble bearing can be designed as a non-rotating bearing. The wobble bearing can be arranged on an axial end of the motor shaft and can be slidably mounted on the motor shaft by means of at least one fastening means. For this purpose, it is advantageous that a relative rotation between the wobble bearing and the motor shaft can be inhibited in relation to one another, so that a longitudinal axial stroke movement of the piston of the air spring compressor can be generated by arranging the wobble bearing. Advantageously, the wobble bearing can be fixed in a rotationally fixed manner in a longitudinal guide at the axial end of the motor shaft. Advantageously, the wobble bearing can be connected to the piston and its lifting movement can drive the piston. Advantageously, at least one shaft bearing, in particular at least one roller bearing, can be mounted on the motor shaft to guide and support the revolving motor shaft.

As an alternative to the previous embodiment, the wobble bearing can be designed as a rotating bearing that supports the non-rotatable motor shaft. For this purpose, the wobble bearing can serve as the rotor of the motor and the motor shaft mounted therein can be connected in a rotationally fixed manner and preferably to the piston (18). In this embodiment, the motor shaft moves longitudinally and axially, with the wobble bearing being axially fixed but rotatably mounted around the motor shaft. The lifting movement of the motor shaft serves to drive the piston.

It is also conceivable that a rotatable wobble bearing or a rotatable motor shaft is connected to the piston via a pivot bearing, so that a rotating element such as a wobble bearing and/or motor shaft can also perform a lifting movement and be used to drive the stationary piston.

In a further advantageous development, at least one positive guide for converting rotational rotations into axial movements can be formed in the wobble bearing and/or in the motor shaft. Advantageously, the restraint can be designed as an endless guide or as a closed guideway of a sliding, sliding or rolling element such as a ball, a guide lug, a rolling body, etc. This can advantageously be achieved in that the wobble bearing is offset longitudinally axially along the motor shaft in an oscillating manner during a 360° rotation of the motor shaft, in particular during a 360° rotation of the motor shaft performs at least one complete oscillating movement.

Based on the previous embodiment, at least one rolling element can be provided between the swash bearing and the motor shaft, so that movement of the rolling element along the restraint allows a longitudinal axial movement of the swash bearing relative to the axis of rotation of the motor shaft. Advantageously, the rolling element can be designed as a bearing ball, which can run along a closed guideway designed as a restricted guide. The guideway may be at least partly arranged on a surface of the end portion of the motor shaft or on an inner surface of the wobble bearing, and the rolling element is to be arranged on the complementary part accordingly.

In a further advantageous development, two wobble bearings can each be arranged on the two opposite axial ends of the motor shaft, so that a two-stage double-piston air spring compressor is formed with a low-pressure stage and a high-pressure stage. It is therefore proposed in this embodiment to first carry out a compression of air in the low-pressure stage, in which the air is compressed for the first time in the low-pressure stage by means of a first piston and then enters the high-pressure stage and can be further compressed there by means of a second piston. An air outlet of the low-pressure stage can advantageously be connected to an air inlet of the high-pressure stage, with the air being able to be compressed to a medium pressure by means of the first piston before the air is admitted to the high-pressure stage, and the compressed air in the high-pressure stage being able to be post-compressed by means of the second piston. It is advantageous that higher pressures can be achieved with the same amount of air compared to a single-piston air spring compressor. In order to enable a rotational movement of the motor shaft to be converted into a longitudinal axial stroke movement of the pistons without connecting rods and eccentrics, the two wobble bearings are to be arranged in this development, with the two wobble bearings being able to be mounted on the two opposite axial ends of the motor shaft by means of at least one fastening means. Alternatively, a single wobble bearing can drive both pistons, in particular drive them offset by 180°.

Based on the previous embodiment, different stroke lengths can be configured in the low-pressure stage and the high-pressure stage. By setting different stroke lengths of the respective pressure stage, varying nominal pressure values of each cylinder can be determined in the corresponding pressure stage. It is advantageous that different pressure levels can be generated, in particular cascaded, by connecting several compression stages in series.

In addition, a compressed air system, in particular a compressed air spring system, of a vehicle is proposed in a secondary aspect of the invention. The compressed air system comprises at least one air spring compressor, which is designed according to one of the aforementioned possible embodiments.

In a further subordinate aspect, a vehicle is proposed which comprises a compressed air system, in particular a compressed air spring system according to the above embodiment.

character list

Further advantages result from the present description of the drawings. Exemplary embodiments of the invention are shown in the drawings. The drawing, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into further meaningful combinations.

• 1 in einer perspektivischen Darstellung ein Luftfederkompressor gemäß einer Ausführungsform;
• 2 in einer perspektivischen Darstellung ein Luftfederkompressor gemäß einer weiteren Ausführungsform;
• 3 in einer perspektivischen Darstellung ein Taumellager eines Luftfederkompressors gemäß einer weiteren Ausführungsform;
• 4 in einer perspektivischen Darstellung ein Taumellager eines Luftfederkompressors gemäß einer weiteren Ausführungsform;
• 5 Vorderansicht des in 4 dargestellten Taumellagers;
• 6a Seitenansicht des in 4 dargestellten Taumellagers; und
• 6b einen Längsschnitt A-A durch das in 4 dargestellte Taumellager.

Show it:

• 1 in a perspective view, an air spring compressor according to an embodiment;
• 2 in a perspective view, an air spring compressor according to a further embodiment;
• 3 in a perspective view, a wobble bearing of an air spring compressor according to a further embodiment;
• 4 in a perspective view, a wobble bearing of an air spring compressor according to a further embodiment;
• 5 Front view of the in 4 illustrated swash bearing;
• 6a Side view of the in 4 illustrated swash bearing; and
• 6b a longitudinal section AA through the in 4 illustrated swash bearing.

Elements of the same type are denoted by the same reference symbols in the figures. The figures only show examples and are not to be understood as limiting.

the 1 shows a first embodiment of an air spring compressor 10 in which a wobble bearing 12 is arranged. A stator 24 and a rotor 22 of an electric motor 36 are arranged in a housing 32 of the air spring compressor 10 , the electric motor 36 being provided as an electric drive motor 36 . During operation, a motor shaft 14 rotates about an axis of rotation C in a direction of rotation A. A shaft bearing 20 is arranged to guide and support the revolving motor shaft 14, it being possible for the shaft bearing 20 to be designed as a roller bearing. In order to convert rotational movements of the motor shaft 14 into longitudinal axial stroke movements of a piston 18 of a cylinder 16 along a stroke direction B, the wobble bearing 12 is arranged in a stationary manner on an axial end 40 of the motor shaft 14, wherein the wobble bearing 12 can be designed as a rotationally fixed bearing and with the piston 18 is connected. Thus, a stroke axis D of the piston 18 corresponds to the axis of rotation C of the motor shaft 14, the piston 18 being moved by the pendulum motion tion of the wobble bearing 12 along the motor shaft 14 is driven.

Due to the fact that the air spring compressor 10 is provided with the wobble bearing 12, an eccentric and a connecting rod with a connecting rod bearing can be dispensed with, so that a low oscillating mass is possible during operation of the electric motor 36 and this leads to low vibrations and an improvement in the acoustics can. Furthermore, a forced guidance 26 is provided in the wobble bearing 12 with respect to the motor shaft 14, the forced guidance 26 acting as a closed guideway 28 for at least one rolling element 30 (in the 1 not shown) is formed. Because the rolling element 30 runs along the forced guidance 26 between the wobble bearing 12 and the motor shaft 14 , a longitudinal axial movement of the wobble bearing 12 relative to the axis of rotation C of the motor shaft 14 can be made possible.

In the 2 Another embodiment of an air spring compressor 10 with a wobble bearing 12 is shown. A motor shaft 14 of an electric motor 36 designed as an electric drive motor 36 can rotate about an axis of rotation C in a direction of rotation A, with a stator 24 being arranged around the motor shaft 14 . A shaft bearing 20 is arranged to guide and support the revolving motor shaft 14 and the wobble bearing 12 to convert a rotary rotation of the motor shaft 14 into a longitudinal axial movement of the wobble bearing 12 . Compared to the wobble bearing 12 in the 1 is that in the 2 intended wobble bearing 12 rotatably mounted and serves as the rotor of the motor. Furthermore, the wobble bearing 12 is not arranged at the axial end 40 of the motor shaft 14, but encloses the surface 44 of the motor shaft 14 and supports the stationary motor shaft 14. The motor shaft 14 is mounted so that it can move longitudinally and axially, with the cylinder piston 18 being firmly connected to the motor shaft . The cylinder piston 18 is moved in the rotating wobble bearing 12 by an axial pendulum movement of the motor shaft. The wobble bearing also has fastening means 42 . A restricted guide 26 designed as a closed guideway 28 is provided in the rotatable wobble bearing 12 and in the non-rotatable and longitudinally axially movable motor shaft 14, with at least one rolling element 30 (in the 2 not shown) is arranged, so that during operation of the electric motor 36, a longitudinal axial lifting movement of the motor shaft 44 and thus of the piston 18 of the cylinder 16 can be made possible by movement of the rolling element 30 along the positive guide 26 of the rotating wobble bearing 12. A stroke axis D corresponds to the axis of rotation C of the motor shaft 14.

In the 3 a further embodiment of a wobble bearing 12 is shown, wherein the wobble bearing 12 is arranged to convert a rotational movement of a motor shaft 14 into a longitudinal-axial oscillating movement of the motor shaft 14 relative to the wobble bearing 12 . In order to achieve this, a spiral restraint 26 is formed in the motor shaft 14, with the restraint 26 being able to be formed as a closed guide track 28. Two rolling elements 30 can move between the wobble bearing 12 and the motor shaft 14 along the forced guidance. Furthermore, the wobble bearing 12 can be fastened to the motor shaft 14 by means of fastening means 42 . The possibility arises of designing the wobble bearing 12 to be stationary and using it to drive the piston 18 , or designing the motor shaft 14 to be stationary and using it to drive the piston 18 . Accordingly, either the motor shaft 14 is part of the rotor, or the wobble bearing 12.

In the 4 , 5 , 6a , 6b 1 is another embodiment of a wobble bearing 12 that may be attached to a motor shaft 14 by fasteners 42 . The wobble bearing 12 is arranged on the end face of the motor shaft 14 and the end face of the wobble bearing 12 can be designed as a piston 18 at the same time. Due to the fact that a restricted guide 26 is formed in the motor shaft 14 and in the wobble bearing 12 , rolling elements 30 can run along the restricted guides 26 between the wobble bearing 12 and the motor shaft 14 . As a result, a rotation of the motor shaft 14 can be converted into a longitudinal axial oscillating movement of the motor shaft 14 . The restraints 26 are designed as spiral-like, closed guideways 28 .

Reference List

10

air spring compressor

12

swash bearing

14

motor shaft

16

cylinder

18

Pistons

20

shaft bearing

22

runner

24

stator

26

restraint

28

guideway

30

rolling element

32

casing

34

vehicle compressed air system

36

Electric motor, electric drive motor

38

Double piston air suspension compressor

40

axial end

42

fasteners

44

surface

A

direction of rotation

B

stroke direction

C

axis of rotation

D

lifting axis

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was 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.

Patent Literature Cited

• EP 1375919 A1 [0003]
• DE 10005929 A1 [0004]

Claims (10)

Air spring compressor (10) for a vehicle, preferably for a vehicle compressed air system (34), in particular for a vehicle air spring system, comprising an electric drive motor (36) attached to a rotatable motor shaft (14), characterized in that a lifting axis (D) of a piston (18) of the air spring compressor (10) corresponds to an axis of rotation (C) of the electric drive motor (36). Air spring compressor (10) after claim 1 , characterized in that a wobble bearing (12) is arranged at least on one axial end (40) of the motor shaft (14), with a rotary movement of a rotor (22) of the electric drive motor (36) in a longitudinal axis relative to the wobble bearing (12). oscillating movement of the motor shaft (14) can be converted, and the wobble bearing (12) drives the piston (18). Air spring compressor (10) after claim 1 or 2 , characterized in that the wobble bearing (12) is designed as a rotationally fixed bearing, which is preferably connected to the piston (18). Air spring compressor (10) after claim 1 or 2 , characterized in that the wobble bearing (12) is designed as a rotating bearing, which supports the non-rotatable motor shaft (14), and preferably the motor shaft (14) is connected to the piston (18). Air spring compressor (10) according to one of the preceding claims, characterized in that at least one restricted guide (26) for converting rotational rotations into axial movements is formed in the wobble bearing (12) and/or in the motor shaft (14). Air spring compressor (10) after claim 5 , characterized in that at least one rolling element (30) is provided between the wobble bearing (12) and the motor shaft (14), so that movement of the rolling element (30) along the restraint (26) causes a longitudinal axial movement of the wobble bearing (12) opposite the axis of rotation (C) of the motor shaft (14) can be made possible. Air spring compressor (10) according to one of the preceding claims, characterized in that two wobble bearings (12) are each arranged on the two opposite axial ends (40) of the motor shaft (14), so that a two-stage double-piston air spring compressor (38) with a low-pressure stage (42) and a high-pressure stage (44) is formed. Air spring compressor (10) after claim 7 , characterized in that different stroke lengths are formed in the low-pressure stage (42) and high-pressure stage (44). Compressed air system (34), in particular compressed air spring system, of a vehicle, comprising at least one air spring compressor (10) according to one of the preceding claims. Vehicle comprising a compressed air system (34), in particular a compressed air spring system claim 9 .

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