Pump device

Abstract

A pump device for a motor vehicle includes: a pump having a first pump member and a second pump member, the first and second pump members being movable relative to one another; an electric drive having a drive housing and an output shaft rotatable with respect to the drive housing; and a gear mechanism, which couples the output shaft to the first pump member and, by reversing a direction of rotation of the electric drive, is switchable between a first and an opposite second transmission ratio. The gear mechanism has: a planet stage having a planet carrier rotationally fixed relative to the drive housing, and/or first and second freewheels, oppositely directed with respect to one another, and which are arranged axially behind one another, and/or the second pump member has a drive shaft rotatable relative to the output shaft.

Claims

1. A pump device for a motor vehicle, the pump device comprising: a pump having a first pump member and a second pump member, the first pump member and the second pump member being movable relative to one another; an electric drive having a drive housing and an output shaft rotatable with respect to the drive housing; a gear mechanism, which couples the output shaft to the first pump member and, by reversing a direction of rotation of the electric drive, is switchable between a first transmission ratio and an opposite second transmission ratio, wherein the gear mechanism has: a planet stage having a planet carrier rotationally fixed relative to the drive housing, and a first freewheel and a second freewheel, oppositely directed with respect to one another, and which are arranged axially one behind the other, and the second pump member has a drive shaft rotatable relative to the output shaft, wherein the first pump member is connected by the first freewheel to a sun wheel and/or connected in the second freewheel to an annulus of the planet stage of the gear mechanism, and wherein a second drive, comprising an internal combustion engine, is coupled to the drive shaft.

2. The pump device as claimed in claim 1, wherein the output shaft is connected by the first freewheel to the first pump member and/or the output shaft is rotationally fixed to the sun wheel of the planet stage of the gear mechanism.

3. The pump device as claimed in claim 1, wherein the first pump member comprises a pump housing and the second pump member comprises a rotor arranged in the pump housing.

4. A motor vehicle comprising: the pump device as claimed in claim 1; and a vehicle transmission, wherein the pump device is configured as a hydraulic supply of the vehicle transmission.

5. A method for operating the pump device as claimed in claim 1, wherein the electric drive is operated in a first operating mode with a first direction of rotation and in a second operating mode with an opposite second direction of rotation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantageous developments of the present invention will emerge from the following description of preferred embodiments. To this end, in the figures, in part in a schematic manner:

(2) FIG. 1 shows a pump device;

(3) FIG. 2 shows another exemplary pump device;

(4) FIG. 3 shows another exemplary pump device;

(5) FIG. 4 shows another exemplary pump device; and

(6) FIG. 5 shows a method for operating one of the exemplary pump devices according to the present invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

(7) FIG. 1 shows a pump device according to one embodiment of the present invention in an axial or meridian section.

(8) The pump device has a pump having a first pump member in the form of a rotatably mounted pump housing 10 and second pump member in the form of a rotor 11 rotatably arranged in the pump housing 10.

(9) The pump device has an electric drive having a drive housing 20 and an output shaft 21 which can be rotated with respect thereto, and a gear mechanism having a planet stage which couples the output shaft 21 to the one (first) pump member or pump housing 10.

(10) The second pump member, the rotor 11, has a drive shaft 50 rotatable relative to the output shaft 21 and arranged concentrically in the hollow output shaft 21 and is coupled to a second drive, in one embodiment an internal combustion engine (not shown).

(11) The planet stage has a sun wheel 31 to which the output shaft 21 is connected in a rotationally fixed manner, an annulus 34 which is mounted rotatably relative to the drive housing 20 by bearings 60, and planets 33 whose external toothing is in engagement with an external toothing of the sun wheel 31 and an internal toothing of the annulus 34 and which are rotatably mounted on a planet carrier 32 of the planet stage, which planet carrier is arranged in a rotationally fixed manner relative to the drive housing 20.

(12) The first pump member, pump housing 10, is connected in one freewheel 41 to the sun wheel 31 or the output shaft 21 and in one oppositely directed further freewheel 42 to the annulus 34.

(13) The two freewheels 41, 42 are arranged axially behind one another.

(14) In a first operating mode (FIG. 5: S10), the electric drive is operated with a first direction of rotation or rotates its output shaft 21 relative to its drive housing 20 in a first direction of rotation.

(15) Here, freewheel 41 locks such that the output shaft 21 and the first pump member, pump housing 10, rotate jointly at the same rotational speed.

(16) By virtue of the fixed planet carrier 32, the planets 33 rotate the annulus 34 in a direction of rotation opposite to the first direction of rotation of output shaft 21 or pump housing 10. Here, the freewheel 42 directed oppositely with respect to the freewheel 41 opens.

(17) In a second operating mode (FIG. 5: S20), the electric drive is operated with a second direction of rotation opposite to this first direction of rotation or rotates its output shaft 21 relative to its drive housing 20 in an opposite second direction of rotation.

(18) By virtue of the fixed planet carrier 32, the planets 33 rotate the annulus 34 in a direction of rotation opposite to this second direction of rotation of the output shaft 21. Here, the freewheel 42 directed oppositely with respect to the freewheel 41 now locks and the annulus 34 rotates the one (first) pump member or pump housing 10 in the opposite direction to the second direction of rotation of the output shaft 21, wherein freewheel 41 opens.

(19) Consequently, the gear mechanism is switched between a first and opposite second transmission ratio solely by reversing the direction of rotation of the electric drive.

(20) By varying the difference between the rotational speed of rotor 11 (by drive shaft 50) and pump housing 10 (by electric drive 20, 21), the operating point of the pump can be advantageously varied and, moreover, drive energy from the internal combustion engine can be used.

(21) FIG. 2 shows a pump device according to a further embodiment of the present invention in an illustration corresponding to FIG. 1. Features corresponding to one another are identified by identical reference signs, such that reference is made to the above description and differences will be discussed below.

(22) In the embodiment of FIG. 2, the freewheels 41, 42 are arranged radially above one another.

(23) FIG. 3 shows a pump device according to a further embodiment of the present invention in an illustration corresponding to FIG. 1. Features corresponding to one another are identified by identical reference signs, such that reference is made to the above description for FIG. 1 and differences will be discussed below.

(24) In the embodiment of FIG. 3, the pump housing 10 is rotationally fixed relative to the drive housing 20, and the drive shaft 50 for driving the pump housing 10 is dispensed with.

(25) The first pump member is, in this case, the rotor 11, and the second pump member is the pump housing 10 in which the rotor 11 is arranged.

(26) The gear mechanism or the planet stage couples the output shaft 21 of the electric drive to the first pump member, rotor 11.

(27) The first pump member, the rotor 11, is connected in the freewheel 41 to the sun wheel 31 or the output shaft 21 and in the oppositely directed further freewheel 42 to the annulus 34.

(28) In the first operating mode, freewheel 41 locks such that the output shaft 21 and the first pump member, the rotor 11, rotate jointly at the same rotational speed (transmission ratio=1).

(29) By virtue of the fixed planet carrier 32, the planets 33 rotate the annulus 34 in a direction of rotation opposite to the first direction of rotation of output shaft 21 or rotor 11. Here, the freewheel 42 directed oppositely with respect to the freewheel 41 opens.

(30) In the second operating mode, the electric drive is operated with an opposite direction of rotation or rotates its output shaft 21 relative to its drive housing 20 in an opposite direction of rotation.

(31) By virtue of the fixed planet carrier 32, the planets 33 rotate the annulus 34 in a direction of rotation opposite to this direction of rotation of the output shaft 21. Here, the freewheel 42 directed oppositely with respect to the freewheel 41 now locks and the annulus 34 rotates the first pump member, the rotor 11, in the opposite direction to the direction of rotation of the output shaft 21, wherein freewheel 41 opens. The transmission ratio is (in terms of value) not equal to 1.

(32) FIG. 4 shows a pump device according to a further embodiment of the present invention in an illustration corresponding to FIG. 3. Features corresponding to one another are identified by identical reference signs, such that reference is made to the above description for FIG. 3 and differences will be discussed below.

(33) In the embodiment of FIG. 4, the freewheels 41, 42 are arranged radially above one another.

(34) Although exemplary embodiments have been discussed in the above description, it should be noted that numerous modifications are possible. Furthermore, it should be noted that the exemplary embodiments are merely examples which are not intended to limit the scope of protection, applications and structure in any way. Rather, the above description will provide a person skilled in the art with a guideline for implementing at least one exemplary embodiment, wherein various modifications, in particular with regard to the function and arrangement of the described constituent parts, may be made without departing from the scope of protection as defined by the claims and by these equivalent combinations of features.

(35) TABLE-US-00001 List of reference signs 10 Pump housing 11 Rotor 20 Drive housing 21 Output shaft 31 Sun wheel 32 Planet carrier 33 Planet 34 Annulus 41, 42 Freewheel 50 Drive shaft 60 Bearing

(36) Thus, while there have been shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.