Method and apparatus for controlling a load of an engine associated with a hydrostatic drive system
AssigneeCaterpillar Inc.
InventorsAlan L. Ferguson, Conrad G. Grembowicz, Larry E. Kendrick
Life of this patent
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Abstract
An apparatus for controlling the load of an engine associated with a hydrostatic drive system is disclosed. The apparatus includes a variable displacement pump rotatably driven by the engine. The apparatus modifies a pump displacement command signal in response to the actual and desired engine speed acceleration. The modified pump displacement command signal is used to control the displacement of a variable pump in order to regulate the load on the engine to achieve optimum efficiency.
Claims16
An apparatus for controlling a load of an engine associated with a hydrostatic drive system, comprising:
- a variable displacement pump rotatably driven by the engine;
- means for sensing the rotational speed of the engine and producing an actual engine speed signal indicative of the rotational engine speed;
- means for producing a desired engine speed signal indicative of a desired rotational speed of the engine;
- means for producing a pump command signal indicative of a desired pump displacement;
- means for receiving the actual and desired engine speed signals, determining a load control coefficient responsive to the difference between the actual and desired engine speed signals, and responsively modifying the pump command signal based on the determined load control coefficient;
- and
- means for receiving the modified pump command signal and responsively controlling the variable pump displacement to regulate the engine load.
A method for controlling a load of an engine associated with a hydrostatic drive system, the hydrostatic drive system including a variable displacement pump rotatably driven by the engine, comprising the steps of:
- sensing the rotational speed of the engine and producing an actual engine speed signal indicative of the rotational engine speed;
- producing a desired engine speed signal indicative of a desired rotational speed of the engine;
- producing a pump command signal indicative of a desired pump displacement;
- receiving the actual and desired engine speed signals, determining a load control coefficient responsive to the difference between the actual and desired engine speed signals, and responsively modifying the pump command signal based on the determined load control coefficient;
- and
- receiving the modified pump command signal and responsively controlling the variable pump displacement to regulate the engine load.
Dependencies are inferred from the claim text.