Electro-hydraulic pump displacement control with proportional force feedback
AssigneeCaterpillar Inc.
InventorsAleksandar M. Egelja, Mikhail A. Sorokine
Life of this patent
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Abstract
A pump displacement control arrangement uses the inherent swivel torques of a fluid translating device in cooperation with a proportional force feedback to more consistently and precisely control the displacement of the fluid translating device. The subject invention uses a variable displacement control arrangement having an actuator mechanism coupled to a swash plate of the fluid translating device and controlled by a proportional valve arrangement to control the displacement of the fluid translating device. A force feedback mechanism is disposed between the actuator mechanism and the proportional valve arrangement and provides a more precise and repeatable displacement control.
Claims16
A variable displacement control arrangement, comprising:
- a variable displacement fluid translating device having a pressure outlet port and a displacement adjusting member;
- an actuator mechanism connected to the displacement adjusting member and configured to move the displacement adjusting member;
- a source of pressurized fluid;
- a proportional valve arrangement in communication with the actuator mechanism and the source of pressurized fluid;
- the proportional valve arrangement configured to selectively direct the pressurized fluid to the actuator mechanism, thereby causing movement of the displacement adjusting member;
- the pressurized fluid supplied to the proportional valve arrangement always having a substantially constant pressure.
A method of controlling the displacement of a fluid translating device having a displacement adjusting member, comprising:
- providing a source of pressurized fluid;
- providing an actuator mechanism connected to the displacement adjusting member;
- providing a proportional valve arrangement between the source of pressurized fluid and the actuator mechanism, the proportional valve arrangement configured to selectively direct the pressurized fluid to the actuator mechanism;
- the pressurized fluid supplied to the proportional valve arranaement always having a substantially constant pressure.
A method of controlling the displacement of a fluid translating device having a displacement adjusting member, comprising:
- providing a source of pressurized fluid;
- providing an actuator mechanism connected to the displacement adjusting member, the actuator mechanism having a first end portion and a second end portion;
- providing a proportional valve arrangement between the source of pressurized fluid and the actuator mechanism;
- and
- sizing the cross sectional area of at least one of the first and second end portions of the actuator mechanism to counteract a maximum swivel force acting to change the displacement of the fluid translating device.
Dependencies are inferred from the claim text.