EP1934478B1 - Vane cell pump - Google Patents

Description

The invention relates to a vane pump having an outer rotor, an inner rotor and a plurality of vanes, which are mounted radially displaceably in substantially radial slots in the inner rotor and pivotally mounted on the outer rotor and the outer rotor slides along the inner peripheral surface of a stator, wherein the axis of the stator and the axis of the inner rotor have an offset from one another and the stator with respect to the inner rotor in the radial direction adjustable and thereby the offset is variable, and the stator is partially surrounded by a mounted in the housing of the vane pump in a pivot bearing bracket.

From the DE 100 40 711 A1 is a vane pump with an annular inner rotor known, in which a plurality of radially outwardly extending wing elements are received radially displaceable. The radially inner end portions of the wing elements are supported on a non-rotatable central part, the radially outer end portions of a non-rotatable outer ring. The rotor can be rotated about a rotation axis that is offset from the central axis of the central part and the outer ring. In this way, at a rotational movement of the rotor between the wing elements initially larger and then smaller again conveying cells. Due to the change in volume of the delivery cells fluid is first sucked into the delivery cells and then ejected again. The end regions of the wing elements slide on the central part or the outer ring. Such a vane pump can be made simple and inexpensive.

To increase the efficiency is from the DE 195 32 703 C1 a vane pump in the form of a pendulum slide pump known. In this, the wing elements are slidably received in an inner rotor, whereas they are pivotally supported in an annular outer rotor. The axis of rotation of the inner rotor is offset with respect to the axis of rotation of the outer rotor, whereby in operation also initially magnifying and then shrinking conveyor cells are formed. The from the DE 195 32 703 C1 However, known pendulum slide pump is complex and therefore expensive to manufacture.

The invention has for its object to provide a vane pump whose pumping power is sensitive adjustable.

This object is achieved with a vane pump of the type mentioned fact that the bracket on both sides of the pivot bearing projecting bracket arms, and the bracket arms embrace the stator in each case partially.

The inventive design of the vane pump, the possibility is created that the stator is moved not only by means of a single bail arm, for which the stator must be firmly connected to the bail arm, but that the stator is surrounded by the two bracket arms that embrace this bifurcated. In this case, in one embodiment, only one of the bracket arms are subjected to a pressure, whereas the other arm is driven in other ways, for example by means of a spring. Or in another embodiment, both arms can each be subjected to a pressure, so that the position of the stator is determined by the two pressures. In this way, a very fine setting or positioning of the stator can be achieved, which is required for map control. Because the two Bail arms drive the stator in opposite directions, even the smallest pressure changes in the positioning of the stator can be considered. In particular, it is not necessary to work against a spring constant, which has the disadvantage that it is necessary to work against a changing force of a spring, that is to say against a spring constant. It can directly the resulting pressures for displacing the stator, to be used in both directions.

In a further development it is provided that both bow arms are hydraulically or pneumatically pivotable. In this case, for example, the prevailing in the system oil pressure can be used to control, or in pneumatic systems, the prevailing positive or negative pressure can be used to control the hanger arms.

In a further development it is provided that a bail arm is pivotable by means of a spring. In a variant, it is provided that the stator is adjustable by means of a spring. This spring, which is in particular biased, has the task to adjust the bracket and / or the stator in the direction of maximum delivery of the pump, that is, either maximum pressure or maximum negative pressure. This is necessary if in a fault, the pneumatic or hydraulic control of the hanger arms fails. The control of the strap by means of the mechanical spring ensures that the system is supplied with the required hydraulic or pneumatic pressure or with the pneumatic negative pressure. In this case, the spring may be a coil spring, leaf spring, leg spring or a pneumatic cushion.

For easy control of the hanger arms, the invention provides that the free ends of the hanger arms have piston surfaces for a pressure medium. About the size of the piston surfaces, the adjusting force can be determined so that the applied pressure can be passed directly to the piston surfaces.

Preferably, the piston surfaces are slidably mounted in provided in the housing of the vane pump guides. These guides serve on the one hand for sealing the piston relative to the housing, on the other hand for the exact guidance and storage of the free ends of the hanger arms.

Further advantages, features and details of the invention will become apparent from the subclaims and the following description in which two preferred embodiments are described in detail with reference to the drawing. The features shown in the drawing and mentioned in the claims and in the description may each be essential to the invention individually or in any combination.

Figur 1

einen Querschnitt durch eine Flügelzellenpumpe, teilweise aufgeschnitten;

Figur 2

eine perspektivische Ansicht einer Flügelzellenpumpe ohne Gehäuse gemäß einer ersten Ausführungsform; und

Figur 3

eine perspektivische Ansicht einer Flügelzellenpumpe ohne Gehäuse gemäß einer zweiten Ausführungsform.

In the drawing show:

FIG. 1

a cross section through a vane pump, partially cut open;

FIG. 2

a perspective view of a vane pump without housing according to a first embodiment; and

FIG. 3

a perspective view of a vane pump without housing according to a second embodiment.

The FIG. 1 schematically shows a housing 10 of a generally designated 12 vane pump, in which a drive shaft 14 is rotatably mounted. This drive shaft 14 drives an inner rotor 16, which has a plurality of radial slots 18, in which wings 20 are mounted radially displaceable. These wings 20 have a thickened free end 22 to which sliding blocks 24 are pivotally mounted. These sliding shoes 24 abut against the inner circumferential surface 26 of a stator 28 and form an outer rotor designated overall by 8. In this case, the inner rotor 16, two wings 20, two sliding blocks 24 and the stator 28 each form a working space 30. This is clearly in the cut-section of the vane pump 12 in FIG. 1 recognizable. The working space 30 increases and decreases with rotating inner rotor 16, whereby a fluid is conveyed.

Moreover, in the FIG. 1 It can be seen that in a housing-fixed pivot bearing 32, a fork-shaped bracket 34 is pivotally mounted, wherein the bracket 34 has two bracket arms 36 and 38 which at least partially abut the stator 28 and embrace this. This is also clear from the Figures 2 and 3 seen. The free ends 40 and 42 of the yoke arms 36 and 38 have piston surfaces 44, which acts on a prevailing in the pressure chambers 46 and 48 fluid. The bail arms 36 and 38 are guided in guides 50, via which they are sealed fluid-tight and wherein the guides 50 represent cylindrical surfaces.

For example, if a pressure acts on the piston surface 44 of the free end 40 of the bail arm 36, then the bail arm 36 and thus the entire bail 34 is pivoted in the direction of the arrow 52 about the pivot axis of the pivot bearing 32, whereby the stator 28 in the direction of the arrow 52 is taken. In the in the FIG. 1 As shown, the stator 28 has an axis 54 which has an offset 60 with respect to the axis 56 of the drive shaft 40. By the Displacement of the stator 28 in the direction of the arrow 52, this offset 60 is reduced, thereby reducing the eccentricity of the inner rotor 16 to the stator 28 or outer rotor 8, whereby the working volume of the vane pump 12 is reduced.

An increase in the working volume is achieved in that the bracket 34 is pivoted against the direction of the arrow 52 by a pressure on the piston surface 44 of the end 42 of the bail arm 38 engages. On the bracket 34, therefore, the resultant force acts on the piston surfaces 44 prevailing pressures.

When in the FIG. 3 shown embodiment engages on the underside of the stator 28 in a suitable manner, a mechanical spring 58, in particular a coil spring, which tries to move the stator 28 against the direction of the arrow 52. This displacement direction acts in the direction of maximum delivery of the vane pump 12.

Should be in an accident neither on the piston surface 44 of the bail arm 36 still on the piston surface 44 of the bail arm 38 apply pressure, then the stator 28 is displaced in any case in the direction of maximum promotion, thereby ensuring that the vane pump 12, the fluid to be pumped or a negative pressure sufficiently provides. This spring 58 is only used to adjust the vane pump 12 for the accident. The regular return of the stator 28 in the direction of the maximum delivery takes place by applying a pressure to the piston surface 44 of the bail arm 38 or by reducing the pressure on the piston surface 44 of the bail arm 36.

Claims (9)

1. Vane cell pump (12) comprising an external rotor (8), an inner rotor (16) and a plurality of vanes (20), which are displaceably mounted in a radial manner in essentially radial slots (18) in the inner rotor (16) and which are secured in a pivotable manner on the external rotor (8) and the external rotor (8) is sliding along the inner circumferential surface (26) of a stator (28), where the axis (54) of the stator (28) and the axis (56) of the inner rotor (16) are offset (6) in relation to one another and where the stator (28) can be adjusted in a radial direction in relation to the inner rotor (16) thereby allowing the offset (60) to be modified, and the stator (28) is partially enclosed by a clamp (34) which is mounted in a pivotable bearing (32) in the housing (10) of the vane cell pump (12), characterized in that the clamp (34) comprises clamp arms (36 and 38) which protrude on both sides of the pivotable bearing (32) and the clamp arms (36 and 38) partly enclose, respectively, the stator (28).
2. Vane cell pump according to claim 1, characterized in that the clamp (34) is of fork-like design due to its clamp arms (36 and 38).
3. Vane cell pump according to claim 1 or 2, characterized in that both of the clamp arms (36 and 38) can be pivoted hydraulically or pneumatically.
4. Vane cell pump according to one of the preceding claims, characterized in that a clamp arm can be displaced by means of a spring (58).
5. Vane cell pump according to one of the preceding claims, characterized in that the stator (28) can be adjusted by means of a spring (58).
6. Vane cell pump according to claim 4 or 5, characterized in that the spring (58) is pretensioned.
7. Vane cell pump according to claims 4 through 6, characterized in that the clamp arm and/or the stator (28) can be adjusted in the direction of maximum output of the vane cell pump (12) by means of the spring (58).
8. Vane cell pump according to one of the preceding claims, characterized in that the free ends (40 and 42) of the clamp arms (36 and 38) feature piston surfaces (44) for a pressure medium.
9. Vane cell pump according to claim 8, characterized in that the piston surfaces (44) are displaceably mounted in guides (50) provided in the housing (10) of the vane cell pump (12).

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