Automatic transmission and control method for electric oil pump
AssigneesJATCO Ltd, Nissan Motor Co., Ltd.
InventorHideharu YAMAMOTO
Life of this patent
Estimating the term…
Abstract
An automatic transmission includes a mechanical oil pump, an electric oil pump, and a controller. The controller calculates a flow rate of oil necessary for the automatic transmission during the vehicle travels, and drives the electric oil pump when the calculated flow rate of the oil necessary for the automatic transmission is higher than a margin flow rate of the mechanical oil pump generated in a state where a hydraulic pressure necessary for the automatic transmission is ensured.
Claims9
-5. (canceled)
An automatic transmission mounted on a vehicle, comprising:
- a mechanical oil pump driven by an engine, the mechanical oil pump supplying oil to the automatic transmission;
- an electric oil pump driven by an electric motor, the electric oil pump supplying oil to the automatic transmission;
- and
- a controller that calculates a flow rate of the oil necessary for the automatic transmission during the vehicle travels, the controller driving the electric oil pump when the calculated flow rate of the oil necessary for the automatic transmission is higher than a margin flow rate of the mechanical oil pump, the margin flow rate being generated after a hydraulic pressure necessary for the automatic transmission has come to a state of being ensured, the margin flow rate being a flow rate of oil available for filling the oil in an oil chamber of a clutch of the automatic transmission to be engaged so as to cause a clutch piston to stroke.
A control method for an electric oil pump in an automatic transmission, the automatic transmission being mounted on a vehicle, the automatic transmission including a mechanical oil pump and an electric oil pump, the mechanical oil pump being driven by an engine, the electric oil pump being driven by an electric motor, the mechanical oil pump and the electric oil pump supplying oil to the automatic transmission, the control method comprising:
- calculating a flow rate necessary for the automatic transmission during the vehicle travels;
- driving the electric oil pump when the calculated flow rate necessary for the automatic transmission is higher than a margin flow rate of the mechanical oil pump, the margin flow rate being generated after a hydraulic pressure necessary for the automatic transmission has come to a state of being ensured, the margin flow rate being a flow rate of oil available for filling the oil in an oil chamber of a clutch of the automatic transmission to be engaged so as to cause a clutch piston to stroke.
An automatic transmission mounted on a vehicle, comprising:
- a mechanical oil pump driven by an engine, the mechanical oil pump supplying oil to the automatic transmission;
- an electric oil pump driven by an electric motor, the electric oil pump supplying oil to the automatic transmission;
- means for calculating a flow rate of the oil necessary for the automatic transmission during the vehicle travels;
- and
- means for driving the electric oil pump when the calculated flow rate of the oil necessary for the automatic transmission is higher than a margin flow rate of the mechanical oil pump, the margin flow rate being generated after a hydraulic pressure necessary for the automatic transmission has come to a state of being ensured, the margin flow rate being a flow rate of oil available for filling the oil in an oil chamber of a clutch of the automatic transmission to be engaged so as to cause a clutch piston to stroke.
Dependencies are inferred from the claim text.