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EP-4505072-B1 - BIDIRECTIONAL AUTOMOTIVE POSITIVE-DISPLACEMENT PUMP

EP4505072B1EP 4505072 B1EP4505072 B1EP 4505072B1EP-4505072-B1

Inventors

  • VEZENTAN, Vlad-Dumitru
  • HENDRIKS, JAN

Dates

Publication Date
20260506
Application Date
20220405

Claims (11)

  1. Bidirectional automotive positive-displacement pump (10) comprising: - a pump rotor (15) being rotatably and eccentrically arranged within a pumping chamber (13), - a static pump housing (12) defining the pumping chamber (13) with • a pumping chamber inlet/outlet opening (17), • a pumping chamber outlet/inlet opening (18) being arranged mirror-symmetrically to the pumping chamber inlet/outlet opening (17), and • a neutral zone (19) being arranged at the apoapsis (A) of the pumping chamber (13) between the pumping chamber inlet/outlet opening (17) and the pumping chamber outlet/inlet opening (18), - an overpressure-relief channel (20) fluidically connecting the pumping chamber inlet/outlet opening (17) and the pumping chamber outlet/inlet opening (18), and - an overpressure-relief valve (25) for opening and closing the overpressure-relief channel (20), the overpressure-relief valve (25) being arranged such that an overpressure is released from the pumping chamber inlet/outlet opening (17) to the pumping chamber outlet/inlet opening (18) or alternatively from the pumping chamber outlet/inlet opening (18) to the pumping chamber inlet/outlet opening (17) if the pressure is above a predefined overpressure value, wherein the overpressure-relief valve (25) is arranged such that an overpressure-relief valve actuating axis (D) is oriented substantially perpendicularly to a flow direction (F) of the overpressure-relief channel (20).
  2. Bidirectional automotive positive-displacement pump (10) according to claim 1, wherein the overpressure-relief valve (25) is mechanically pressure-actuated.
  3. Bidirectional automotive positive-displacement pump (10) according to claim 1 or 2, wherein the overpressure-relief valve (25) is a linear slide valve.
  4. Bidirectional automotive positive-displacement pump (10) according to one of the preceding claims, wherein the overpressure-relief valve (25) is mechanically biased by a compression spring (27).
  5. Bidirectional automotive positive-displacement pump (10) according to one of the preceding claims, wherein the overpressure-relief valve (25) is arranged within the pump housing (12).
  6. Bidirectional automotive positive-displacement pump (10) according to one of the preceding claims, wherein the overpressure-relief valve actuating axis (D) is arranged in a separating plane (S) which symmetrically separates the pumping chamber inlet/outlet opening (17) and the pumping chamber outlet/inlet opening (18).
  7. Bidirectional automotive positive-displacement pump (10) according to one of the preceding claims, wherein an overpressure-relief valve body (26) is substantially cylindrical.
  8. Bidirectional automotive positive-displacement pump (10) according to one of the preceding claims, wherein the overpressure-relief channel (20) is defined by the pump housing (12).
  9. Bidirectional automotive positive-displacement pump (10) according to one of the preceding claims, wherein the overpressure-relief channel (20) is bypassing the neutral zone (19).
  10. Bidirectional automotive positive-displacement pump, according to one of the preceding claims, wherein the bidirectional positive-displacement pump (10) is an oil pump.
  11. Bidirectional automotive positive-displacement pump, according to one of the preceding claims, wherein the bidirectional positive-displacement pump (10) is a gerotor pump.

Description

The invention is directed to a bidirectional automotive positive-displacement pump for pumping oil within an oil circuit of a vehicle. A positive-displacement pump, in particular a so-called gerotor pump can generate relatively large pressures within its pumping chamber, in particular within a high-pressure discharge zone. As a result, a relatively large driving torque can be required for rotating the pump rotor against the high counter-pressure from the discharge zone. Furthermore, the relatively large discharge pressures can cause damages to the pressure lines of a connected pressure circuit and to the connected consumer devices. Therefore, a positive-displacement pump, in particular a gerotor pump can be provided with an overpressure-relief valve for releasing the overpressure from the high-pressure discharge zone to a low-pressure suction zone of the pumping chamber. The high-pressure discharge zone and the low-pressure suction zone are fluidically connected via a connection channel which is openable and closable by a simple unidirectional check valve. The check valve is spring-biased and is actuated purely mechanically by the overpressure. If the pressure exceeds a defined overpressure value, the valve opens the connection channel so that the pressure is released to the suction zone until the nominal discharge pressure is achieved within the discharge zone. The overpressure value thereby is substantially defined by the preload of the said spring. Exemplary pumps are disclosed in the documents DE 10 2013 207 321 A1, US 9,909,715 B2 or EP 2 781 750 B1. The rotational direction of the pump rotor can in some applications be reversed so that the pump rotor can rotate in both rotational directions. A valve system switches the flow direction within the connected pressure circuit to guarantee the unidirectional supply of the pressure circuit independently of the rotational direction of the pump. An example of such a bidirectional gerotor pump is disclosed in the US 6,017,202 A, in US 2 791 966 A or in US 4 828 462 A,. It is an object of the present invention to provide a bidirectional automotive positive-displacement pump with a bidirectional overpressure-relief valve that is releasing the overpressure from a high-pressure zone to a low-pressure zone independently of the rotational direction of the pump rotor. It is another object of the present invention to provide a bidirectional automotive positive-displacement pump comprising an overpressure-relief valve with a compact design. These objects are achieved by a bidirectional automotive positive-displacement pump according to the present invention with the features of main claim 1. A bidirectional automotive positive displacement pump comprises a pump rotor which is rotatably arranged within a pumping chamber. The bidirectional automotive positive displacement pump further comprises a static pump housing which defines said pumping chamber. The pumping chamber comprises a pumping chamber inlet/outlet opening, a pumping chamber outlet/inlet opening which is arranged mirror symmetrically to the pumping chamber inlet/outlet opening and a neutral zone being arranged at the apoapsis of the pumping chamber between the pumping chamber inlet/outlet opening and the pumping chamber outlet/inlet opening. The pump rotor is eccentrically arranged within the pump chamber, thereby several pumping compartments are defined that change their volume over one rotation of the pump rotor within the pumping chamber. Thereby, each pumping compartment sucks fluid depending on the rotational direction of the pump rotor either through the pumping chamber inlet/outlet opening or through the mirror symmetrical pumping chamber outlet/inlet opening into the pumping chamber. As the automotive positive displacement pump according to the invention is bidirectionally driveable, i.e., is able to pump fluid independently of the rotational direction of the pump rotor, the pumping chamber inlet/outlet opening is in a first rotational direction, for example, in a clockwise rotational direction an inlet opening and in the second rotational direction, for example, in a counter-clockwise rotational direction an outlet opening. The rotational direction of the pump rotor defines a suction zone and a discharge zone. Within the suction zone, the volume of each pumping compartment increases during the rotation of the pump rotor, wherein the volume of each pumping compartment decreases during the rotation of the pump rotor within the discharge zone. The suction zone and the discharge zone are symmetrically separated by the eccentricity axis defined by the axis through the centre of the pump rotor and through the centre of the pumping chamber. In the first rotational direction, for example, the clockwise rotation, the pumping chamber inlet/outlet opening is an inlet opening through which the increasing pumping compartments suck fluid from a fluid source into the pumping chamber. Thereby, the low-pressure sucti