Patent ID: 11905954
Assignee: NOK CORPORATION
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 0:
1. An electric pump, comprising:
a driving shaft including a rotational axis;
a driving rotor and a driven rotor that are driven by rotation of the driving shaft;
a driven shaft configured to rotate the driven rotor;
a driving gear disposed on the driving shaft, the driving gear being configured to transmit the rotation of the driving shaft;
a driven gear disposed on the driven shaft, the driven gear being configured to transmit the rotation of the driving shaft;
an electric motor configured to rotate the driving shaft; and
a housing that includes a gear chamber, a rotor chamber, and a motor chamber, the gear chamber accommodating the driving gear and the driven gear and encapsulating oil supplied to the driving gear and the driven gear, the rotor chamber accommodating the driving rotor and the driven rotor, the motor chamber accommodating the electric motor, wherein
the motor chamber, the gear chamber, and the rotor chamber are arranged in order in a rotational axial direction of the driving shaft,
the housing includes a first partition wall that separates the gear chamber from the rotor chamber and a second partition wall that separates the gear chamber from the motor chamber,
the first partition wall includes a first through-hole through which the driving shaft passes and a second through-hole through which the driven shaft passes,
the second partition wall includes a third through-hole through which the driving shaft passes,
the electric pump further comprises:
a first seal member arranged in the first through-hole to seal a space between the gear chamber and the rotor chamber;
a second seal member arranged in the second through-hole to seal the space between the gear chamber and the rotor chamber; and
a third seal member arranged in the third through-hole to seal a space between the gear chamber and the motor chamber,

the third seal member seals the space between the gear chamber and the motor chamber to a lesser extent than the first seal member and the second seal member seal the space between the gear chamber and the rotor chamber,
the third seal member includes a seal surface adjacent to the driving shaft, the seal surface including a first helical groove, and
the first helical groove connects an inside of the gear chamber to an inside of the motor chamber.