Sealing device and electric motor

An electric motor comprising:

• a housing with an opening;
• a shaft within the opening;
• and
• a sealing device that is disposed between the housing and the shaft, and that seals a gap between an inner peripheral surface of the housing and an outer peripheral surface of the shaft, wherein the sealing device comprises:
• an annular reinforcing ring fixed to the housing;
• an annular elastic member comprising:
• a fixing portion fixed to the reinforcing ring;
• and
• a lip that protrudes from the fixing portion and is in slidable contact with an outer peripheral surface of the shaft;
• and
• at least one annular spring that presses the lip against the outer peripheral surface of the shaft, wherein:
• the lip is between the outer peripheral surface of the shaft and the at least one spring,
• the elastic member is made of an electrically conductive elastic material,
• the lip includes a contact surface in contact with the outer peripheral surface of the shaft, and
• the contact surface is straight in a natural state when viewed in a cross section defined by a plane that includes a central axis of the elastic member;
• and
• wherein, a thickness of a part of the lip between the at least one spring and the outer peripheral surface of the shaft is defined as t, and a width of the contact surface in an axial direction of the shaft is defined as W1, and a relationship between t and W1 satisfies the following inequality:
• t<W1.