Cooling Lubrication System Comprising A Dry Sump

Abstract

A cooling lubrication system comprises a dry sump, an oil tank, and a pump system that operates an oil circuit in which an oil pump delivers oil from the dry sump into the oil tank, and the pump system comprises a vane cell pump and two gerotor pumps on a shaft.

Claims

1. A cooling lubrication system comprising: a dry sump, an oil tank, and a pump system that operates an oil circuit in which an oil pump delivers oil from the dry sump into the oil tank, wherein the pump system comprises a vane cell pump and two gerotor pumps on a shaft.

2. A cooling lubrication system according to claim 1, wherein the vane cell pump is of a double-flow design and comprises two independent suction points in the dry sump.

3. A cooling lubrication system according to claim 1, wherein the double-flow vane cell pump has a common pressure outlet.

4. A cooling lubrication system according to claim 1, wherein one of the two gerotor pumps is connected on the pressure outlet side to under-vane grooves in the vane cell pump.

5. A cooling lubrication system according to claim 1, wherein the gerotor pumps are connected on the pressure side to a gear supply and a cooling for an electric machine.

Description

FIGURES

[0019] FIG. 1 shows an inventive embodiment of the cooling lubrication system with a dry sump.

[0020] FIG. 2 shows an embodiment for two pumps.

DETAILED DESCRIPTION

[0021] FIG. 1 shows a cooling lubrication system 1 equipped with a dry sump 3 and an oil tank 6, with a pump system 2 ensuring the circulation of the lubricant.

[0022] The pump system 2 consists of three pumps 4 driven on a common shaft 5 by a common electric machine EM.

[0023] The pump P1 comprises two suction ports 10 P1 and 11 P1. The pump P1 sucks the oil from the dry sump 3 at two points and delivers the oil into the oil tank 6 via the pressure outlet 12 P1 and the oil tank inlet 6a.

[0024] The two suction points S in the dry sump 3 independently suck oil from the dry sump such that one of the two suction points S still delivers oil, even if the other suction point already sucks air or an air-oil mixture.

[0025] The pump P1 is a vane cell pump of a double-flow design, with the two flows being configured separately from each other. In this way, two separate delivery circuits are created which are each connected to a suction point S in the dry sump 3. However, the two delivery circuits are connected to each other on the pressure side and supply a pressure outlet 12P1.

[0026] Disposed adjacent to the vane cell pump P1, on the same shaft 5, is a first gerotor pump P2. The gerotor pump P2 delivers oil from the oil tank 6 via the port 6b and the pump inlet 14P2, for example for a gear supply 7. The second gerotor pump P3 is disposed adjacent to the gerotor pump P2. The gerotor pump P3 delivers oil from the oil tank 6 via the port 6c, the pump inlet 16P3 and the pressure outlet 17P3, for example for cooling an electric machine 8.

[0027] The supply of the consumers, the gear and the electric machine is merely an example since further consumers are also conceivable.

[0028] In the pump system 2, the first gerotor pump P2 is also used, in addition to its delivery function, for the supply of a gear in order to preload the vane cell pump P1 in terms of pressure. In vane cell pumps, the problem arises that during start-up the vanes of the vane cell pump do not initially rest on the stroke ring, thus impairing the efficiency of the pump. To prevent this, a vane cell pump comprising at least one under-vane groove is used, into which oil is fed at a specific pressure such that the vanes are brought towards the stroke ring.

[0029] The gerotor pump P2 therefore comprises at its pump outlet a branch 15 P2 with which oil is applied under pressure to the inlet 13 P1 of the under-vane grooves of the vane cell pump P1.

[0030] A complicated integrated gerotor pump in the vane cell pump, as suggested in prior art, is thus avoided. The pump intended for gear supply is used for two functions. The pump system 2 allows a small construction and thus a reduction of costs.

[0031] FIG. 2 schematically demonstrates how the two pumps P1 and P2 are connected to each other. Via the branch 15P2, the gerotor pump P2 is on the outlet side connected to the inlet to the under-vane area of the vane cell pump P1. Starting from the branch 15P2, the gerotor pump P2 feeds in oil for the gear supply 7.