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US 9,309,881 B2Granted
Electric pump system
AssigneeJtekt Corporation
InventorsKengo Uda, Yasuyuki Aoki, Hiroki Kagawa
Life of this patent
Estimating the term…
Abstract
In an electric pump system, hydraulic fluid that is stored in an oil pan is supplied to a transmission mechanism through an oil passage by driving an oil pump with the use of a motor. An EOPECU estimates a hydraulic pressure of the hydraulic fluid on the basis of a driving current for the motor and a rotation speed of the motor, and executes drive control on the motor on the basis of the estimated hydraulic pressure value.
Claims16
A system for supplying hydraulic fluid to a hydraulically-actuated device through an oil passage, comprising:
- an electric motor driven by electrical power supplied from a battery, wherein the battery voltage decreases over time from a voltage set in advance;
- motor control means for controlling at least a driving current of the electrical power for driving the electric motor;
- an oil pump driven by the electric motor and that supplies the hydraulic fluid to the hydraulically-actuated device through the oil passage as the electric motor is driven;
- and
- hydraulic pressure estimating means for estimating the hydraulic pressure value of the hydraulic fluid in the oil passage, based on the driving current for the motor and a rotation speed of the electric motor,
- wherein the motor control means executes drive control on the electric motor based on the estimated hydraulic pressure value of the hydraulic fluid in the oil passage,
- and wherein the motor control means corrects the estimated hydraulic pressure value based on the decrease of the voltage of the electrical power from the battery as compared to the voltage set in advance, for driving the electric motor.
4 more elements
Dependencies are inferred from the claim text.