Rotary actuator
AssigneeDenso Corporation
InventorsHiroyuki KADO, Taku ITO
Life of this patent
Estimating the term…
Abstract
A rotary actuator includes: an electric motor; a case that receives the electric motor; a rotatable body that is configured to transmit an output of the electric motor to an outside of the case; a seal member that seals between the rotatable body and the case; and a labyrinth forming portion that forms a labyrinth space in a path that extends from an outside space of the case to a sealing point of the rotatable body, at which the rotatable body is sealed by the seal member.
Claims19
A rotary actuator as a drive device of a shift-by-wire system for a vehicle, comprising:
- an electric motor;
- a case that receives the electric motor;
- a rotatable body that is configured to transmit an output of the electric motor to an outside of the case;
- a seal member that seals between the rotatable body and the case;
- and
- a labyrinth forming portion that forms a labyrinth space in a path that extends from an outside space of the case to a sealing point of the rotatable body, at which the rotatable body is sealed by the seal member, wherein:
- the rotatable body has a stepped shaft portion that includes a large diameter portion and a small diameter portion, wherein the large diameter portion and the small diameter portion are located on a side of the sealing point where the outside space is located;
- the large diameter portion is positioned on a side of the small diameter portion where the sealing point is placed;
- the labyrinth forming portion includes a ring portion that is placed on a radially outer side of the small diameter portion;
- an inner diameter of the ring portion is smaller than an outer diameter of the large diameter portion;
- and
- the labyrinth space is located between an inner wall surface of the ring portion and an outer wall surface of the small diameter portion and also between a side wall surface of the ring portion and an end surface of the large diameter portion.
A rotary actuator as a drive device of a shift-by-wire system for a vehicle, comprising:
- an electric motor;
- a case that receives the electric motor;
- a rotatable body that is configured to transmit an output of the electric motor to an outside of the case;
- a seal member that seals between the rotatable body and the case;
- and
- a labyrinth forming portion that forms a labyrinth space in a path that extends from an outside space of the case to a sealing point of the rotatable body, at which the rotatable body is sealed by the seal member, wherein:
- the labyrinth forming portion includes a tubular portion that is placed on the outside space side of the sealing point and is on a radially outer side of the rotatable body;
- the tubular portion includes a drain passage, wherein the drain passage is a space in an inside of the tubular portion and communicates a space, which is located between the sealing point and the labyrinth space, to the outside space;
- and
- the drain passage is a passage in a form of a labyrinth.
Dependencies are inferred from the claim text.