WO2005001291A1

WO2005001291A1 - Pump

Info

Publication number: WO2005001291A1
Application number: PCT/DE2004/001264
Authority: WO
Inventors: Ivo Agner
Original assignee: Luk Fahrzeug-Hydraulik Gmbh & Co. Kg
Priority date: 2003-06-30
Filing date: 2004-06-18
Publication date: 2005-01-06
Also published as: DE502004011746D1; ATE483913T1; DE102004030473B4; EP1642032A1; DE102004030473A1; EP1642032B1

Abstract

The invention relates to a pump, such as a vane-cell pump or a roller cell pump, especially for gear lubricant oil or for automatic gearboxes, said pump comprising a stroke contour ring, a rotor containing radial slits in which vanes or rollers are arranged in a radially displaceable manner, and lateral plates or housing lateral walls defining the rotation group in an axially lateral manner. The ejection openings, so-called reniform pressure elements, are arranged in the lateral plates or housing lateral walls in the pressure region of the pump.

Description

pump

The invention relates to a pump, such as a vane pump or roller cell pump, in particular for transmission oil for automatic transmissions, with a stroke contour ring, with a rotor with radial slots in which vanes or rollers are arranged so as to be radially displaceable, with side plates or side walls of the housing which axially limit the rotation group laterally, wherein discharge openings, so-called pressure kidneys, are arranged in the side plates or side walls of the housing in the printing area.

Transmission pumps for automatic transmissions usually work with foamed transmission oil and have a suction filter. Due to the undissolved air in the oil, air can accumulate in the filter. Many small to large air bubbles come together here. If such an air bubble is now sucked in, there will be crackling noises. The air bubble has the effect, for example, that a large part of the cell in a vane pump is filled with air and that the cell does not have enough time as part of the pressure compensation process controlled by pressure compensation notches or intermediate capacities (see DE 10027990), which are arranged in the so-called pre-compression area Fill oil. The pressure equalization process is now completed relatively suddenly when the large pressure kidneys of the standard pumps are opened. This quickness creates very high pressure peaks, which are acoustically reflected in the crackling noise.

Critical operating states for this case are:

Low speeds and high pressures, because due to the low flow velocities through the filter, the air bubbles are particularly strong.

The noise that occurs when the pump is partially empty.

The noise when the pump works in cavitation, for example at low oil temperatures. The effect of the cavitation vacuole is comparable to that of a large air bubble.

In all these conditions, the angle of rotation for the pressure compensation processes in the pre-compression area is not sufficient to fill the cell in a standard pump. An acceleration of the pressure compensation processes by z. B. Larger pressure compensation notches in the pre-compression area leads to an inadmissible deterioration of the noise due to increasing pressure gradients in the other operating states.

It is therefore an object of the invention to present a pump which does not have these problems.

The object is achieved by a pump, such as a vane pump or a roller cell pump, in particular for transmission oil for automatic transmissions, with a stroke contour ring, with a rotor with radial slots in which vanes are arranged in a radially displaceable manner, with side plates or side walls of the housing which delimit the rotation group axially laterally, whereby discharge openings, so-called pressure kidneys, are arranged in the side plates or housing side walls in the pressure area, the sum of the cross-sectional areas of both pressure kidneys of a pressure area (a flood) of the pump, based on one and the same cell, i.e. within the area of a cell above which Angle of rotation is significantly reduced compared to standard pumps. A pump is preferred in which the sum of the cross-sectional areas of both pressure kidneys of a pressure area (a flood) of the pump, based on one and the same cell, ie within the area of a cell, both with single-stroke (single-flow) and with double-stroke, that is, double-flow vane pumps or roller cell pumps in total do not exceed 40 mm ² per cm ³ cell volume over a rotation angle of 20 °. This dimensioning has the advantage that an acceptable noise behavior can be achieved for high-pressure gear pumps with operating pressures above 20 bar for the aforementioned operating states.

A pump according to the invention is characterized in that the sum of the cross-sectional areas of both pressure kidneys of a pressure area (a flood) of the pump, based on one and the same cell, ie within the area of a cell, increases essentially linearly or slightly progressively over the angle of rotation.

Furthermore, a pump is preferred in which the cross-sectional areas of both pressure kidneys of a pressure area, that is to say the front and rear pressure kidneys, are of the same size, that is to say arranged symmetrically. This has the advantage that the axially acting pressure surfaces on the rotor are balanced.

Another pump according to the invention is characterized in that the cross-sectional areas of both pressure kidneys of a pressure area are not of equal size, that is to say are arranged asymmetrically. A pump is also preferred in which the cross-sectional area of the pressure kidney of this pressure area, which is connected to the pressure outlet, is larger than z. B. the opposite Overlying cross-sectional area of the pressure kidney of this pressure area, which is not connected to the pressure outlet (thus has no through opening and thus represents a so-called shadow port). This has the advantage that the pressure kidney connected to the pressure outlet generates less resistance and thus less losses when the fluid is ejected from the cell to be compressed.

It is immaterial here whether only one pressure kidney is directly connected to the pressure outlet or both (based on a pressure range), since the oil can practically flow past the wing sides from the leading cell into the cell to be filled.

The opening behavior can therefore also be designed asymmetrically, i.e., the pressure kidney on one side can be opened a little faster than on the other side, based on the same pressure range. This is advantageous if the pressure kidney is only connected directly to the pressure outlet on one side plate in order to achieve a large cross-sectional area on this side in particular.

Therefore, a pump is further preferred in which the area ratio of the pressure kidney of a pressure area, which is connected to the pressure outlet, to the pressure kidney of the same pressure area, which is not connected to the pressure outlet, is less than or equal to 70 to 30 if the pressure kidneys are above one Angle of rotation of 20 ° are open.

A pump according to the invention is characterized in that the cross-sectional areas of the (gently opening) pressure kidneys are generated by covering the pressure kidney edges of the side plates with the cam ring contour. This has the following advantages: If the cell is not filled properly due to large air bubbles or cavitation or the like, the remaining oil can be thrown outwards due to the centrifugal force in the cell. After opening the pressure kidneys, it seems more appropriate to push an oil column in front of you with the oil flowing back from the pressure side than to let the oil shoot directly into the air bubble or vacuole.

A pump is also preferred in which the cross-sectional areas of the (gently opening) pressure kidneys are produced by covering the pressure kidney edges of the side plates with the rotor. Furthermore, a pump is preferred in which the cross-sectional areas of the (gently opening) pressure kidneys are created by creating continuously expanding pressure kidneys on the side plates or side walls or on the contour ring. There is also the possibility of reducing the area of the pressure kidney areas by means of a large pressure notch, a flattening or the like. However, since this has to be done in the discharge area for multi-stroke vane pumps for reasons of space, this area is also directly lost as the discharge area and generates additional pressure losses at higher speeds.

The invention will now be described with reference to the figures.

FIG. 1 shows two top views of a rotating group with the pressure kidneys according to the invention.

Figure 2 shows two views of a rotary group with pressure kidneys of a standard pump.

FIG. 3 shows a curve with the derivation of the cell volume according to the angle of rotation over the angle of rotation and the corresponding angular ranges of the pressure kidney according to the invention.

Figure 1 shows a top view of a rotating group with the pressure kidney according to the invention from both sides. A rotor 3 is rotatably arranged within a stroke contour ring 1. The rotor 3 has a plurality of radially displaceable vanes 5 which slide in vane slots 7 in the rotor. The direction of rotation of the rotor for the two views is indicated by an arrow of rotation 9. In Figure 1b z. B. result in the direction of rotation 9 enlarging cells in the area 11, which 12 can suck oil from the suction kidney there. In the pressure area, the cross-sectional area 13 according to the invention of a pressure kidney of a pressure area (a flood) of the pump, based on one and the same cell, that is to say within the area of a cell, is shown, which is partly by a cavity 15 in the side plate behind the stroke contour ring (1) continues and has a constant or slightly increasing width over the rotation angle. In front of the pressure area, a pressure compensation notch 17 is arranged in the pre-compression area, which already allows a certain amount of pre-compression in the large circle area before the cross-sectional area 13 of a pressure kidney of a pressure area (a flood) of the pump, based on one and the same cell, i.e. within the area of a cell, is opened to the outlet. The pressure kidneys begin where, or a little later, where the leading wing of the cell under consideration with its opening edge leaves the pre-compression area (great circle area). The position of the pressure kidneys and thus the discharge area can be advanced in the direction of rotation compared to a standard pump. The ejection area can be formed in the stroke contour ring (1) by a parabolic contour function. The general function of such a vane pump with its suction and discharge processes is known. In the view in Figure 1a the other side of the rotation group is shown. Here, too, the cross-sectional area 13 of a pressure kidney of a pressure area (a flood) of the pump, based on one and the same cell, that is to say within the area of a cell, is represented with a partial area 15 by a hollow in the side plate behind the stroke contour ring. However, the pre-compression notch 17 is omitted on this pressure plate side.

In contrast to this, standard vane cell pumps, as shown in FIG. 2, have a pressure kidney 19 behind the pre-compression notch 17, which opens immediately with a very large cross-section and thus immediately connects the cell in the pressure area with relatively little resistance to the entire pressure area outside the rotation group. All other components have the same structure as in FIG. 1 and should therefore not be described in binary terms to avoid repetition.

In Figure 3, the curve of the derivation of the cell volume, which is formed between two vanes, the rotor, the ring and the flat surfaces of the side plates, is shown according to the angle of rotation over the angle of rotation, based on the trailing wing. In addition, the area 33 for the pre-compression notch 17 and the area 35 where the pressure kidney according to the invention is open is shown schematically below the curve.

The curve 20 thus represents the derivation of the cell volume according to the angle of rotation, plotted against the angle of rotation. The area 22 of the curve 20 thus represents the above-mentioned function in the suction area of the vane pump. It extends to point 24, and there the function goes in the pre-compression area 26. The pre-compression area 26 is arranged in the so-called large circle area of the stroke contour. At point 28, the function then passes from the pre-compression area to the discharge area 30 of the vane pump. From this point 38, the connection of the cell with the pressure kidney is established up to point 32. The discharge area 30 extends up to point 32. Since this is a double-stroke (double-flow) pump, the stroke contour is repeated and thus also the function mentioned above.

Claims

claims

1. Pump, such as vane pump or roller cell pump, in particular for transmission oil for automatic transmissions, with a stroke contour ring (1), with a rotor (3) with radial slots ^), in which vanes (5) or rollers are arranged radially displaceably, with side plates or Housing side walls, which axially delimit the rotation group, the discharge openings, so-called pressure kidneys, being arranged in the side plates or housing side walls in the pressure area of the pump, characterized in that the sum of the cross-sectional areas (13) of both pressure kidneys of a pressure area (a flood) of the pump , based on one and the same cell, ie within the area of a cell over which the angle of rotation is significantly reduced compared to standard pumps, in particular not more than less than / equal to 40 mm ² per cm ^{3 of} cell volume over an angle of rotation of 20 °.

2. Pump according to claim 1, characterized in that the sum of the cross-sectional areas (13) of both pressure kidneys of a pressure area (a flood) of the pump, based on one and the same cell, ie within the area of a cell, essentially over the angle of rotation increases linearly or slightly progressively.

3. Pump according to claim 1 or 2, characterized in that the cross-sectional areas (13) of the pressure kidneys of a pressure area, ie the front and rear pressure kidneys, are of the same size, that is to say arranged symmetrically.

4. Pump according to claim 1 or 2, characterized in that the cross-sectional areas (13) of both pressure kidneys of a pressure area are not of equal size, that is to say are arranged asymmetrically.

5. Pump according to claim 4, characterized in that the cross-sectional area (13) of the pressure kidney of a pressure area, which is connected to the pressure outlet, is larger than the cross-sectional area (13) of the pressure kidney of this pressure area, which is not connected to the pressure outlet (a so-called shadow port without through opening).

6. Pump according to claim 4 or claim 5, characterized in that the area ratio of the pressure kidney of a pressure area, which is connected to the pressure outlet, to the pressure kidney of this pressure area, which is not connected to the pressure outlet (Shadow port), less than or equal to 70 to 30, if the pressure kidneys are open over a rotation angle of 20 °.

7. Pump according to one of the preceding claims, characterized in that the cross-sectional areas (13) of the pressure kidneys of a pressure area are generated by covering (15) the pressure kidney edges of the side plates with the cam ring contour (1).

8. Pump according to one of the preceding claims, characterized in that the cross-sectional areas (13) of the pressure kidneys of a pressure area are generated by covering the pressure kidney edges of the side plates with the rotor (3).

9. Pump according to one of the preceding claims, characterized in that the cross-sectional areas (13) of the pressure kidneys are created by creating continuously expanding pressure kidneys on the side plates or side walls or on the contour ring (1).