Continuously variable transmission and control method thereof
AssigneeNissan Motor Co., Ltd.
InventorsRyohey Toyota, Hiromu Terai, Tomoyuki Nakano
Life of this patent
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Abstract
A continuously variable transmission has a primary pulley hydraulic chamber, a secondary pulley hydraulic chamber, a first oil passage connected to the secondary pulley hydraulic chamber, a second oil passage connected to the primary pulley hydraulic chamber, the second oil passage branching from the first oil passage, an electric oil pump provided on the second oil passage so as to allow oil to flow into and flow out from the primary pulley hydraulic chamber, and an oil discharge mechanism configured to discharge oil outside the second oil passage, the oil being to be supplied to the primary pulley hydraulic chamber by the electric oil pump.
Claims8
A continuously variable transmission, comprising:
- a primary pulley hydraulic chamber;
- a secondary pulley hydraulic chamber;
- a first oil passage connected to the secondary pulley hydraulic chamber;
- a second oil passage that is connected to the primary pulley hydraulic chamber, and that branches from the first oil passage;
- an electric oil pump provided on the second oil passage so as to allow oil to flow into and flow out from the primary pulley hydraulic chamber;
- and
- an oil discharge mechanism configured to discharge oil outside the second oil passage,
- wherein electric oil pump is configured to supply the oil to the primary pulley hydraulic chamber.
A control method of a continuously variable transmission for controlling flowing-in and flowing-out of oil with respect to a primary pulley hydraulic chamber by an electric oil pump provided on an oil passage between the primary pulley hydraulic chamber and a secondary pulley hydraulic chamber, the control method comprising:
- supplying oil to the primary pulley hydraulic chamber by the electric oil pump;
- when a flow volume of oil of leakage in the primary pulley hydraulic chamber is less than a lower limit flow volume discharged by the electric oil pump while the electric oil pump rotates at a controllable lower limit rotation speed,
- making the electric oil pump discharge oil of the lower limit flow volume;
- and
- opening a valve so as to partially discharge oil outside the oil passage,
- wherein the electric oil pump supplies the oil to the primary pulley hydraulic chamber.
Dependencies are inferred from the claim text.