Drive unit with two coolant circuits for electric motor
First Claim
1. A drive unit for a vehicle comprising:
- a drive unit case;
an electric motor mounted within said drive unit case;
a first circulation passage for a first coolant, for cooling said electric motor, within the drive unit case;
an inverter for controlling said electric motor; and
a second circulation passage for a second coolant separate from said first circulation passage and including a heat exchange portion within a drive unit case, for heat exchange between the first and second coolants, and a cooling section for cooling the inverter, whereby the first coolant for cooling the electric motor is cooled by the second coolant.
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Accused Products
Abstract
A drive unit includes an electric motor as a power source, and a simplified coolant circuit for cooling the electric motor. The drive unit further includes, in the drive unit case, a circulation passage L for coolant for cooling the motor M. A circulation passage F for a second coolant is provided separate from the circulation passage L for coolant. A heat exchange portion C within the circulation passage L for the first coolant is provided in the drive unit case for heat exchange with the second coolant in the circulation passage F, and the first coolant for cooling the electric motor is cooled by heat transfer to the second coolant in that heat exchange portion C. Accordingly, the coolant circuit in the drive unit case is simplified.
119 Citations
14 Claims
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1. A drive unit for a vehicle comprising:
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a drive unit case;
an electric motor mounted within said drive unit case;
a first circulation passage for a first coolant, for cooling said electric motor, within the drive unit case;
an inverter for controlling said electric motor; and
a second circulation passage for a second coolant separate from said first circulation passage and including a heat exchange portion within a drive unit case, for heat exchange between the first and second coolants, and a cooling section for cooling the inverter, whereby the first coolant for cooling the electric motor is cooled by the second coolant. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
wherein said second circulation passage includes a flow passage for the second coolant formed between said inverter panel and the circulation passage for the first coolant, and the inverter panel serves as the cooling section for the inverter. -
4. A drive unit according to claim 3, further comprising a partition dividing said flow passage for the second coolant into a first chamber on the inverter side and a second chamber on the side of said first circulation passage, said first and second chambers being interconnected in series for flow of the second coolant, in sequence, through the first chamber and then through the second chamber.
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5. A drive unit according to claim 3, further comprising a partition dividing said flow passage for the second coolant into a first chamber on the inverter side and a second chamber on the side of said first circulation passage, and wherein said first and second chambers are connected in parallel to the second circulation passage.
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6. A drive unit according to claim 3 further comprising an electric generator and a circulation passage for the first coolant, for cooling the electric generator, formed in the drive unit case, and an inverter for controlling the electric generator, mounted on said inverter panel.
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7. A drive unit according to claim 4 further comprising an electric generator and a circulation passage for the first coolant, for cooling the electric generator, formed in the drive unit case, and an inverter for controlling the electric generator, mounted on said inverter panel.
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8. A drive unit according to claim 5 further comprising an electric generator and a circulation passage for the first coolant, for cooling the electric generator, formed in the drive unit case, and an inverter for controlling the electric generator, mounted on said inverter panel.
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9. A drive unit according to claim 3, wherein said drive unit case includes a coolant container for the first coolant in a position facing the flow passage for the second coolant.
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10. A drive unit according to claim 9, wherein said coolant container is divided into two parts, one for said electric motor and one for an electric generator.
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11. A drive unit according to claim 10, wherein at least one orifice is provided in said first circulation passage for distributing and changing the ratio of portions of the first coolant to the two parts of the coolant container.
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12. A drive unit according to claim 9, wherein said coolant container has a dam in the vicinity of an outlet thereof.
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13. A drive unit according to claim 9, wherein said coolant container is partially defined by a stator of the electric motor or of an electric generator.
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14. A drive unit according to claim 9, wherein said first circulation passage includes a flow passage through a rotor of the electric motor downstream of the coolant container, said flow passage discharging the first coolant through a discharge hole provided in the rotor.
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Specification