Lubrication system for power transmission unit
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsTatsuya Saito, Yohei Habata
Life of this patent
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Abstract
A lubrication system for a power transmission unit that supplies oil to a starting clutch in an appropriate amount irrespective of an engagement state of the starting clutch. When the friction clutch is completely engaged or disengaged, a first control valve is brought into a low inflow rate mode, and the second control valve is brought into a low outflow rate mode. When the friction clutch is engaged while causing a slip the first control valve is brought into a high inflow rate mode, and the second control valve is brought a high outflow rate mode.
Claims8
A lubrication system for a power transmission unit that cools and lubricates a wet friction clutch and a lubrication site of the power transmission unit by oil, comprising:
- a first control valve that controls a flow rate of the oil delivered from the oil pan to the friction clutch;
- a first oil passage that delivers the oil to the friction clutch at a flow rate regulated by the first control valve;
- a second oil passage that allows the oil to be discharged from the friction clutch after lubricating and cooling the friction clutch;
- a second control valve that controls a flow rate of the oil discharged from the friction clutch through the second oil passage;
- a third oil passage that delivers the oil flowing from the friction clutch through the second oil passage to the lubrication site;
- a fourth oil passage that discharges the oil to the oil pan at a flow rate regulated by the second control valve;
- and
- a controller that controls at least the first control valve and the second control valve,
- wherein the controller is configured to
- bring the first control valve into a low inflow rate mode in which the oil flows into the friction clutch at a low rate, and bring the second control valve into a low outflow rate mode in which the oil is discharged to the oil pan at a low rate or not discharged to the oil pan, when the friction clutch is completely engaged or disengaged, and
- bring the first control valve into a high inflow rate mode in which the oil flows into the friction clutch at a high rate that is higher than the rate in the low inflow rate mode, and bring the second control valve into a high outflow rate mode in which the oil is discharged to the oil pan at a high rate that is higher than the rate in the low outflow rate mode, when the friction clutch is engaged while causing slipping.
Dependencies are inferred from the claim text.