DE102013204504C5 - Vane pump with improved performance - Google Patents

Abstract

A vane pump having a pump housing, a stator at least partially formed by the pump housing or disposed in the pump housing, a rotor eccentrically disposed in the stator and rotatable relative to the stator about a rotor axis of rotation, the rotor having a shaft and at least one Rotor blade comprises and the rotor blade is movably mounted in a direction transverse to the Rotorrationsachse upon rotation of the rotor in an opening of the shaft, wherein the opening in a first region which extends from an outer edge of the shaft into the shaft has a shape, which substantially corresponds to an outer shape of the wing, and wherein the opening in the first area forms a substantially sealing guide for the wing, and wherein the opening has a second area adjoining the first area, by forming at least one pocket.

Description

The invention relates to a vane pump with a pump housing, a stator and a rotor, wherein the rotor can be rotated relative to the stator about a rotor axis of rotation. The rotor includes a shaft and at least one rotor blade movably mounted in an opening of the shaft in a direction transverse to the rotor axis of rotation. The invention further relates to a shaft of a rotor for a vane pump.

From the DE 33 24 873 A1 discloses a vane vacuum pump for an internal combustion engine, which consists of a rotor which is mounted in a stator and is driven in rotation. To even with a cold start with z. As viscous oil to ensure the radial mobility of the wings, a stationary Abstützkurve projects into a radial recess of the rotor and pushes a z. B. stuck wings out of the rotor out. In this case, the support curve protruding in a longitudinal center region of the rotor projects radially beyond the bottom of the guide slots for the vanes in the rotor.

It is an object of the invention to provide a vane pump having an improved pumping capacity and a shaft for a rotor of the vane pump.

These objects are achieved by the pump of independent claim 1 and the shaft of independent claim 8.

The invention relates to a vane pump or rotary piston pump with a pump housing, a stator and a rotor. The stator of the vane pump can be at least partially formed by the pump housing or it is arranged in the pump housing. The rotor is eccentrically located in the stator and can be rotated about a rotor axis of rotation relative to the stator.

The rotor comprises a shaft and at least one rotor blade, wherein the one or more ends or the sliding block or shoes of the rotor blade sealingly engage in a rotation of the rotor to a circumferential inner wall or housing raceway of the stator and the end faces of the rotor or wings to or close to a stator bottom and a stator cover.

The stator forms a pump working space, which is subdivided by the rotor blade (s) into a pressure region and a suction region or into pressure and suction cells. Thereby, upon rotation of the rotor by an increasing cell volume from an inlet, a medium, e.g. As oil or air, sucked into the pump working space, there compressed in itself with the rotation of the rotor steadily decreasing cell volume and discharged at an outlet with an increased pressure.

The shaft has an opening in which the wing or wings are movably supported so that the wing or wings can move in the opening transverse to the rotor axis of rotation. That is, the blade (s) may move into and out of the shaft so as to always have an effective length extending from the shaft to the circumferential inner wall of the stator. The opening may be introduced as a breakthrough in the shaft or be formed on one side of the shaft open slot.

In this case, the opening has a first region, which is formed at least at the opening edge and extends in the direction of the shaft center transversely to the rotor rotation axis, and a second region, which adjoins the first region within the shaft.

The first area forms a sealing guide and support for the reaching into the opening wing, d. h., It has a shape or an outer circumference which corresponds substantially to the shape and the outer circumference of the wing. The second region adjoining the first region of the opening has at least one pocket, d. H. in a surface of the opening in the interior of the shaft, a recess or pocket is introduced, so that the wing in this area neither sealingly abuts the surface of the opening nor learns from the opening in this area a guide.

Alone by the formation of the pocket, the bearing surface of the wing is already reduced in the opening and thereby reduces the frictional resistance of the wing in the opening. To further reduce the frictional resistance, a lubricant z. For example, an oil may be directed to the pocket such that there is a steady lubrication between the inner wall of the opening and the outside of the wing.

The opening has according to the wing on a top, a bottom and two end faces. As the top and bottom are here the sides of the wings are referred to, which extend from the stator bottom to the stator cover, the end faces are corresponding to the stator bottom and the stator cover facing sides of the wing.

The at least one pocket may be formed on the top and / or the bottom of the opening and is preferably arranged centrally. Centered can mean that z. B. at a bag opening the bag not to the end of the hole ranges, but joins the second area another first area that leads the wing. The center may also mean that the pocket does not extend from one end face to the opposite end face, so that a guide for the wing is formed on the front sides or near the end faces on the top and / or bottom of the opening over the entire length of the opening ,

Finally, the pocket may also be formed circumferentially in the opening, wherein the opening has a first area in front of the second area and may have a further first area after the second area.

Even if it has always been talked about a bag or at least a bag, the application also includes several z. B. in the axial or radial direction of the opening behind or juxtaposed pockets z. B. can be separated from each other by a web. The web can then have the dimensions of the first area, so that the wing experiences a guide through the opening inner wall in this area.

The bag can be z. B. act around a groove, with a constant depth or towards the groove center steadily or gradually increasing depth. The groove may also be U-shaped or have any other desired shape. Steady transitions into the groove are preferred in order to weaken the wave as little as possible. The groove may also be formed by a bore which runs on the central axis / rotation axis or parallel to the central axis / rotation axis of the shaft and thus forms a pocket with a curved shape.

The groove or the pocket does not have to have an elaborately machined surface since it does not come into direct contact with the wing surface. By contrast, the guide area or the guide areas for the wing must be machined very precisely in the opening, in order to keep a gap between the wing surface and the inner wall of the opening small while at the same time minimizing the frictional forces between the wing surface and the inner wall of the opening. This can lead to a reduction of the necessary drive power for the vane pump and to a reduced wear d. H. lead to a longer service life of the pump.

Advantage of the shaft opening with the bag is thus that only a portion of the inner opening wall has to be laboriously processed, while the area of the bag requires little or no reworking. This has a positive effect on the manufacturing costs, since the production time is reduced on expensive precision machines.

The vane pump can be a vacuum pump with only one vane, which is inserted through a through-opening of the rotor shaft or into a slot open on one end side of the rotor shaft and can be moved in the opening transversely to the rotor rotation axis. Upon rotation of the rotor, the wing abuts at least one end in each rotational position of the rotor sealingly against the circumferential inner wall of the stator and thus separates the suction region of the pump from the pressure region of the pump. Particularly in the case of the shaft with the slot open on the front side, the pocket in the opening can be easily formed.

In the case of a vacuum pump, the evacuation performance is significantly influenced by the contact of the sliding shoes on the housing track. If the friction between the wing and the opening is too high, then the wing is not properly or only delayed on the housing track, especially in a vacuum pump with only one wing when moving out of the opening. However, this system forms the seal between an inlet side and an outlet side of the pump and thus influences the evacuation performance of the vacuum pump.

The problem of excessive friction occurs especially in vane or vacuum pumps, in which the opening for structural reasons not formed as open on one side slot but is mounted in the central region of a continuous shaft.

In the case of a passage opening, a first region can each be formed on both sides of the opening, so that the wing is in each case guided sealingly in the region of the exit from the shaft in the opening.

The vane or opening, or at least a first portion of the opening, is fluidly connected to the pump working space. For this purpose, a capillary or groove is formed in the first region, via which lubricant can flow out of the pocket.

The supply of the bag with lubricant can be done via a supply line that extends from a lubricant reservoir through the shaft to the bag. According to the invention, the opening in the shaft is wider than the wing and the medium is fed to the pocket laterally from the wing via the end face. This simultaneously prevents jamming of the wing or wings at the corner radii of the aperture opening.

Due to the short length of the shaft for the rotor, the shaft can consist of at least two partial round shaft part bodies in a rotor with only one wing. In a wave with more than one wing, the wave z. B. have the same number of shaft part bodies, such as the rotor Has wings. In these cases, all shaft part body parts of the bag or pockets and the one or more areas for guiding the wing. This makes the insertion of the bag into the opening very easy, since the area of the opening for a corresponding z. B. cutting tool is easily accessible.

Alternatively, it is also possible to introduce an opening in the shaft, which has over its entire length a constant shape with constant diameters. Into this opening can / can then the / the above-described first area / s appropriate inserts are used positively and / or non-positively. To do this, the oversized inserts can be cooled before they are inserted into the opening. In the subsequent warming to room temperature, the inserts expand and thus sit firmly in the opening. The inserts can be glued with appropriate special adhesives in the opening, the special adhesive z. B. can trigger a chemical reaction on the surfaces, so that the two surfaces merge quasi together.

As already indicated above, the vane pump may be a vacuum pump with a rotor blade. Compared to conventional vacuum pumps can be improved with the described vane pump evacuation performance of the vacuum power.

The invention further relates to a shaft for a rotor of a vane pump, z. A vacuum pump, wherein the shaft has at least one opening in which a pump blade can be movably received in a direction transverse to a shaft rotation axis. The shaft is prepared to be connected to a drive unit that rotatably drives the shaft.

The shaft is the shaft described in the preceding paragraph, which has within the opening a pocket to which a lubricant can be supplied.

For the entire description and claims, the term "a" is used as an indefinite article and the number of parts is not limited to a single one. Should "a" have the meaning of "only one", then this will be understood by those skilled in the context or by the use of suitable terms such. For example, "a single" is unambiguously disclosed.

Some embodiments will be explained in more detail with reference to the drawing. Show it:

1 : Sectional view of a generic vane pump with a wing;

2 : Section through a shaft according to the prior art and a wing;

3 : perspective view of a shaft with opening and pocket;

4 : Cut through the wave of 3 with wings.

Although some possible embodiments of the invention have been disclosed in the foregoing description, it is to be understood that numerous other variants of embodiments exist through the possibility of combining all of the cited and further all of the obvious technical features and embodiments. It is further understood that the embodiments are to be understood as examples only, which in no way limit the scope, applicability and configuration. Rather, the foregoing description would suggest a suitable way for the skilled person to realize at least one exemplary embodiment. It should be understood that in an exemplary embodiment, numerous changes in the function and arrangement of the elements may be made without departing from the scope and equivalents disclosed in the claims.

The 1 shows a generic vane pump 1 or vacuum pump 1 with a pump housing 2 a stator 3 and a rotor 4 , The stator 3 forms a pump work space 5 in which the rotor 4 is arranged eccentrically

The rotor 4 has a wave 6 with a passage opening 7 on and a wing 8th in the opening 7 is movably mounted in the direction of the arrow. Ie. the wing 8th can be in the opening 7 so move that the wing tips 8a . 8b or sliding shoes 8a . 8b in every rotational position of the shaft 6 on a circumferential inner wall 9 or housing track 9 can rest against the stator. The wing ends 8a . 8b can also be movable in the wing 8th be stored and in the wing 8th in or out of the wing 8th move out to the plant of the wing ends 8a . 8b on the circumferential inner wall 9 of the stator 2

Alternatively, the wave 6 have a plurality of openings, in this case blind holes or blind holes, which are close to the defined by the rotor rotation shaft R center of the shaft 6 rich, and several wings 8th which occurs when the shaft rotates 6 extend into or out of the blind openings in the blind openings.

The 2 shows a section through a shaft 6 according to the prior art, as z. B. in the vacuum pump 1 is shown with one in the opening 7 inserted wings 8th , The wing 8th lies over the entire length of the opening 7 and along the entire circumference of the opening 7 on the surface 7a the opening 7 at. The large contact surface between wing and surface 7a can lead to a relatively large frictional resistance, which is a movement of the wing 8th in the opening 7 the wave 6 delayed. This may cause a momentary release of one of the wing tips 8a . 8b from the circumferential inner wall 9 of the stator 2 and thereby come to a connection of the suction cell with the pressure cell. To avoid or substantially prevent this, the surface must be 7a the opening become expensive.

The 3 shows a perspective view of a shaft according to the invention 6 a rotor 4 that with a drive device 11 connected or connectable, wherein the drive device 11 the wave 6 rotatably driving. The wave 6 has an opening 7 , here a passageway, on, through which a wing 8th can be plugged.

In the opening 7 or in their surface 7c is a bag 10 incorporated. The pocket 10 is in the longitudinal direction of the opening 7 (transverse to the axis of rotation of the shaft) is not continuous, but formed only in a central region. In front of and behind the bag 10 correspond to the dimensions of the opening 7 essentially the outer dimensions of the wing 8th so that in this area in each case a footbridge 7b is formed, which is the wing 8th as a guide and support within the opening 7 serves.

The pocket 10 can be formed as shown in one or both bearing surfaces for a wing broadside or circumferentially in the opening 7 , The pocket 10 does not have to be continuous as shown, but may consist of several pockets with the same or different dimensions, such as depth. Length, width etc. Between individual pockets, additional support and guide webs for the wing 8th be formed. That's how the bag shown 10 z. B. be divided in the middle and there is another support and guide surface for the wing 8th form.

Because the wing 8th in the area of the bag 10 not with the material of the shaft 6 in contact, must be in the area of the bag 10 no elaborate processing of the bag surface done. This processing is at an opening 7 with a bag 10 on the footbridges 7b limited as the guiding and support surface for the wing 8th are formed. This shortens the machining time of the shaft with expensive machines for producing an optimum sliding surface for the wing 8th ,

The 4 finally shows a section through the shaft 6 of the 3 with the opening 7 with the bag 10 and one through the opening 7 inserted wings 10 , The opening 7 has a first area 7b on top of the jetties 7b forms and the wing 8th Guidance and support within the opening 7 offer, and a second area 10 that the bag 10 forms.

The pocket 10 For example, a lubricant can be supplied which creates a frictional resistance between the blade and the webs 7b further reduced. For this purpose, a not shown supply duct into the bag 10 opens the lubricant from a reservoir, not shown, to the bag 10 conduct. Alternatively, the lubricant may be the pumped medium and by z. B. sucked capillary action in the pocket or fed from the lateral faces.

The lubricant may be at least partially through that in the vacuum pump 1 received medium received and transported through a pump outlet from the pump. If the lubricant is not the pumped by the pump medium, the medium contaminated with the lubricant z. B. be cleaned by filtering in a pump outlet downstream filter unit before re-use or delivery to the environment, if necessary or desired.

LIST OF REFERENCE NUMBERS

1

Vacuum pump, vane pump

2

pump housing

3

stator

4

rotor

5

Pump working space

6

wave

7

opening

7a

surface

7b

Footbridge, first area

8th

wing

8a

Wings end, sliding shoe

8b

Wings end, sliding shoe

9

Inner wall, housing track

10

bag

11

driving device

S

Rotation axis stator

R

Rotor axis of rotation

Claims (8)

Vane pump comprising a pump housing ( 2 ), a stator ( 3 ) passing through the pump housing ( 2 ) at least partially formed or in the pump housing ( 2 ) is arranged a rotor ( 4 ) located in the stator ( 3 ) are arranged eccentrically and relative to the stator ( 3 ) is rotatable about a rotor axis of rotation (R), wherein the rotor ( 4 ) a wave ( 6 ) and at least one rotor blade ( 8th ) and the rotor blade ( 8th ) upon rotation of the rotor ( 4 ) in a passage opening ( 7 ) the wave ( 6 ) is movably mounted in a direction transverse to the rotor rotation axis (R), wherein the passage opening ( 7 ) in a first area ( 7b ) extending from a radial outer edge of the shaft ( 6 ) into the wave ( 6 ), has a shape that substantially corresponds to an outer shape of the wing (FIG. 8th ) and wherein the passage opening ( 7 ) in the first area ( 7b ) a substantially sealing guide for the wing ( 8th ), and wherein the passage opening ( 7 ) to the first area ( 7b ) subsequent second area ( 10 ), in which at least one pocket ( 10 ) is formed, and the rotor blade ( 8th ) in the area of the bag ( 10 ) not sealingly on an inner side of the passage opening ( 7 ), still undergoes a guide, wherein the passage opening ( 7 ) on both open sides each a first area ( 7b ) and the at least one pocket ( 10 ) between the first two areas ( 7b ) into the wave ( 6 ), characterized in that at least one of the first regions ( 7b ) is fluidically connected to a pump working space and in the at least one first area ( 7b ) a capillary or groove is formed, via which a lubricant from the pocket ( 10 ) and / or the passage opening ( 7 ) in the wave ( 6 ) is wider than the rotor blade ( 8th ) and a lubricant of the bag ( 10 ) is supplied laterally from the rotor blade on the end faces. A vane pump according to claim 1, wherein the passage opening ( 7 ) has an upper side, a lower side and two end sides and the at least one pocket ( 10 ) is formed substantially centrally in the top and / or bottom. Vane pump according to one of the preceding claims, wherein the bag ( 10 ) in the passage opening ( 7 ) is formed circumferentially. Vane pump according to one of the preceding claims, wherein the rotor ( 4 ) only one wing ( 8th ), the wing ( 8th ) through the wave ( 6 ) and transversely to the rotor axis of rotation (R) in the shaft ( 6 ) is movable. Vane pump according to one of the preceding claims, wherein the bag ( 10 ) has a machined surface which is domed or substantially smooth or forms a structure, e.g. B. support points for the wing (s) ( 8th ). Vane pump according to one of the preceding claims, wherein the shaft ( 6 ) consists of at least two shaft parts and in each shaft part a part of the pocket ( 10 ) is trained. Vane pump according to one of the preceding claims, wherein the vane pump ( 1 ) a vacuum pump ( 1 ). Shaft for a rotor ( 4 ) a vane pump ( 1 ), where the wave ( 6 ) at least one passage opening ( 7 ) with a bag ( 10 ) for movably receiving at least one wing ( 8th ) and the shaft ( 6 ) is prepared with a drive unit ( 11 ), whereby the shaft ( 6 ) around a wave ( 6 ) according to one of claims 1 to 7.

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