Electronic control system for a variable displacement pump
AssigneeGeneral Signal Corporation
InventorsRobert C. Westveer, John K. Vandervoort
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Abstract
An electronic control system for a variable displacement pump comprises apparatus for sensing the actual position of the displacement determinative element and the actual rotational speed of the pump cylinder block, and for producing representative signals which are combined to produce a signal indicative of actual output flow rate. The displacement determinative elements position and the cylinder rotational speed are sensed directly by sensors mounted within the housing of the pump. The speed sensor is disposed in close proximity to, and aligned with marks inscribed on, the outer surface of the rotatable cylinder block. The volumetric efficiency of the pump is also sensed by and used to determine the actual flow rate.
Claims19
An electronic control system for a variable displacement pump having a housing, a rotatable cylinder block within said housing having a plurality of pistons reciprocating therein, and a positional displacement determinative element for controlling the output flow rate of the pump, said control system comprising:
- means for altering the position of said displacement determinative element so as to change the output flow rate of the pump in response to control signals;
- means for producing a signal representative of a desired output flow rate;
- means for producing a signal indicative of the actual position of said displacement determinative element;
- means for producing a signal indicative of the actual rotational speed of said rotatable cylinder block;
- means for combining said signals indicative of the actual position of the displacement determinative element and the actual rotational speed of the cylinder block and for producing a signal representative of the actual output flow rate;
- and
- means for comparing the signals representative of the desired and actual flow rates and for producing an error signal representative of a difference between said rates and for applying said error signal to said means for altering the position of said displacement determinative element so as to change the actual flow rate and cause said error signal to be decreased.
A method for measuring and using with a device the output rate of a variable displacement pump having a housing, a rotatable cylinder block within said housing having a plurality of pistons reciprocating therein, and a positional displacement determinative element, comprising the steps of:
- a. producing a signal indicative of the actual position of said displacement determinative element;
- b. producing a signal indicative of the actual rotational speed of the rotatable cylinder block;
- c. combining said signals produced in steps a and b to produce the signal indicative of the actual output flow rate;
- and
- d. providing said signal indicative of the actual output flow rate to said device;
- wherein step b includes sensing the passage of marks inscribed on an outer surface of the rotatable cylinder.
A method for measuring and using with a device the output rate of a variable displacement pump having a housing, a rotatable cylinder block within said housing having a plurality of pistons reciprocating therein, and a positional displacement determinative element, comprising the steps of:
- a. producing a signal indicative of the actual position of said displacement determinative element;
- b. producing a signal indicative of the actual rotational speed of the rotatable cylinder block;
- c. combining said signals produced in steps a and b to produce the signal indicative of the actual output flow rate;
- and
- d. providing said signal indicative of the actual output flow rate to said device,
- including step e producing a signal indicative of volumetric efficiency which modifies the signal produced in step c.
A method for controlling the output rate of a variable displacement pump having a housing, a rotatable cylinder block within said housing having a plurality of pistons reciprocating therein, and a positional displacement determinative element, comprising the steps of:
- a. producing a signal representative of a desired output flow rate;
- b. producing a signal indicative of the actual position of said displacement determinative element;
- c. producing a signal indicative of the actual rotational speed of the rotatable cylinder block;
- d. combining said signals produced in steps b and c to produce a signal indicative of the actual output flow rate;
- e. comparing the signals produced in steps a and d and producing an error signal representative of a difference between said signals:
- and
- f. altering the position of the displacement determinative element so as to decrease the magnitude of the error signal produced in step e.
Dependencies are inferred from the claim text.