Rotary vane actuator with fluid actuated mechanical lock

A sealing mechanism for a rotary vane actuator comprising:

• a stator housing having a bore disposed axially therethrough;
• an end cap configured to be assembled to the stator housing;
• a rotor assembly including:
• a central longitudinal shaft having a central axis, and
• at least a first longitudinal vane disposed radially on the central longitudinal shaft, and
• a second longitudinal vane disposed radially on the central longitudinal shaft, a stator assembly including:
• a first stator element disposed in the bore of the stator housing, and
• a second stator element disposed in the bore of the stator housing, wherein the first longitudinal vane and the first stator element define a first pressure chamber inside the bore of the stator housing, the second longitudinal vane and the first stator element define a second pressure chamber inside the bore of the stator housing, the second longitudinal vane and the second stator element define a third pressure chamber inside the bore of the stator housing, and the second longitudinal vane and the first stator element define a fourth pressure chamber inside the bore of the stator housing,
• a seal assembly including:
• a compressible seal slidably mounted on the central longitudinal shaft of the rotor assembly, the compressible seal having an outer circumferential surface received in the bore of the stator housing, the compressible seal being configured to slide axially along the central longitudinal shaft through a central opening sized to receive the central longitudinal shaft,
• a compression member slidably mounted on the central longitudinal shaft and configured to slide axially along the central longitudinal shaft,
• a locking piston slidably mounted on the central longitudinal shaft, the locking piston having an end surface adapted to contact the compression member, a circumferential surface sized to be received in the bore of the housing, and a lateral surface axially opposite from the end surface and adapted to receive actuation fluid, the locking piston being configured to slide axially along the central longitudinal shaft through the central opening,
• a first fluid duct configured to fluidically connect the first pressure chamber and the third pressure chamber to the lateral surface,
• a second fluid duct configured to fluidically connect the second pressure chamber and the fourth pressure chamber to the lateral surface,
• a lock valve assembly comprising a third fluid duct and configured to control fluid flow along the first fluid duct and the second fluid duct based on a fluid pressure provided at the third fluid duct.

A sealing mechanism for a rotary vane actuator comprising:

• a stator housing having a bore disposed axially therethrough;
• an end cap configured to be assembled to the stator housing;
• a rotor assembly including:
• a central longitudinal shaft having a central axis, and
• at least a first longitudinal vane disposed radially on and rigidly connected to the central longitudinal shaft, said first longitudinal vane having a first end surface disposed perpendicular to the central axis and a second end surface disposed perpendicular to the central axis, and
• a second longitudinal vane disposed radially on and rigidly connected to the central longitudinal shaft, said second longitudinal vane having a first end surface disposed perpendicular to the central axis, and a second end surface disposed perpendicular to the central axis, said second vane disposed substantially opposite from the first vane,
• a stator assembly including:
• a first stator element disposed in the bore of the stator housing, and having a first end surface disposed perpendicular to the central axis, and a second end surface disposed perpendicular to the central axis, and
• a second stator element disposed in the bore of the stator housing, and having a first end surface disposed perpendicular to the central axis, and a second end surface disposed perpendicular to the central axis;
• and
• a seal assembly including:
• a compressible seal slidably mounted on the central longitudinal shaft of the rotor assembly, the seal having an outer circumferential surface sized to be received in the bore of the stator housing a first lateral surface adapted for contacting the first end surface of the first stator element, the first end surface of the second stator element, the first end surface of the first longitudinal vane, and the first end surface of the second longitudinal vane, and configured to slide axially along the central longitudinal shaft through a central opening sized to receive the central longitudinal shaft,
• a compression member slidably mounted on the central longitudinal shaft and configured to slide axially along the central longitudinal shaft, the compression member having a first surface adapted to contact a second lateral surface of the compressible seal, wherein the compression member, the end cap, the bore of the stator, the rotor assembly, and the compressible seal define a fluid chamber,
• a locking piston slidably mounted on the central longitudinal shaft, the locking piston having an end surface adapted to contact the compression member, a circumferential surface sized to be received in the bore of the stator housing, and a lateral surface axially opposite from the end surface and adapted to receive actuation fluid, the locking piston being configured to slide axially along the central longitudinal shaft through the central opening,
• a first fluid duct configured to fluidically connect the fluid chamber to the lateral surface,
• a lock valve assembly comprising a second fluid duct and configured to control fluid flow along the first fluid duct based on a fluid pressure provided at the second fluid duct.

A method of actuation of a seal assembly comprising:

• providing a rotary vane actuator including:
• a stator housing having a bore disposed axially therethrough and a collection of holes formed therethrough;
• an end cap configured to be assembled to the stator housing;
• a rotor assembly including:
• a central longitudinal shaft having a central axis, and
• at least a first longitudinal vane disposed radially on the central longitudinal shaft, and
• at least a second longitudinal vane disposed radially on the central longitudinal shaft,
• a stator assembly including:
• a first stator element disposed in the bore of the stator housing, and
• a second stator element disposed in the bore of the stator housing, wherein the first longitudinal vane and the first stator element define a first pressure chamber inside the bore of the stator housing, the second longitudinal vane and the first stator element define a second pressure chamber inside the bore of the stator housing, the second longitudinal vane and the second stator element define a third pressure chamber inside the bore of the stator housing, and the second longitudinal vane and the first stator element define a fourth pressure chamber inside the bore of the stator housing,
• a seal assembly including:
• a compressible seal slidably mounted on the central longitudinal shaft of the rotor assembly, the seal having an outer circumferential surface received in the bore of the stator housing, a first lateral sealing surface and a second lateral sealing surface axially opposite from the first lateral sealing surface, the compressible seal being configured to slide axially along the central longitudinal shaft through a central opening sized to receive the central longitudinal shaft,
• a compression member slidably mounted on the central longitudinal shaft and configured to slide axially along the central longitudinal shaft, the compression member having a first surface and second surface axially opposite from the first surface,
• a locking piston slidably mounted on the central longitudinal shaft, the locking piston including an end surface, a circumferential surface received in the bore of the housing, a lateral surface axially opposite from the first surface, and a biasing member disposed between the compression member and the lateral surface;
• a first fluid duct configured to fluidically connect the first pressure chamber and the third pressure chamber to the end surface of the lock piston;
• a second fluid duct configured to fluidically connect the second pressure chamber and the fourth pressure chamber to the end surface of the lock piston;
• a lock valve assembly comprising a third fluid duct and configured to control fluid flow along the first fluid duct and the second fluid duct based on second fluid pressure provided at the third fluid duct;
• providing first pressurized fluid to one or more of the first pressure chamber, the second pressure chamber, the third pressure chamber, or the fourth pressure chamber;
• providing the first pressurized fluid to the lock valve assembly through one or both of the first fluid duct and the second fluid duct;
• providing the second fluid pressure at the third fluid duct;
• blocking, by the lock valve assembly and based on the second fluid pressure, fluid flow from one or both of the first fluid duct and the second fluid duct to the end surface of the locking piston;
• relieving the second fluid pressure at the third fluid duct;
• providing, through the lock valve assembly and based on the relieved second fluid pressure, the first pressurized fluid to the end surface of the locking piston;
• slidably displacing the locking piston axially along the central longitudinal shaft and contacting the biasing member;
• slidably displacing the biasing member axially along the central longitudinal shaft into contact with the compression member and thereby partially compressing the biasing member;
• and
• contacting the first lateral sealing surface of the compressible seal with the compression member and slidably displacing the compressible seal axially along the central longitudinal shaft into sealing contact with a first end surface of the first longitudinal vane, a first end surface of the second longitudinal vane, a first end surface of the first stator element, and a first end surface of the second stator element.