Rotary helical actuator
First Claim
1. A rotary actuator comprising a cylinder, a shaft rotatably mounted within said cylinder for relative rotation between the shaft and the cylinder, linear-to-rotary motion conversion means between the shaft and cylinder, said motion conversion means including a piston, means for selectively introducing pressurized fluid to alternative sides of said piston for reciprocating the piston and producing said relative rotation, and bearing means for carrying the radial and bending loads between the shaft and cylinder, said bearing means including a cylindrical bearing sleeve joined to said shaft extending along the length of the shaft inward of said cylinder, and spaced radially from the outer surface of the shaft to define an operating chamber for receiving the motion conversion means, and said bearing sleeve having a radially outer bearing surface in engagement with the inner surface of the cylinder.
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Accused Products
Abstract
Helically splined hydraulic actuator provided with hydraulic cushioning and rapid initiation of movement. The actuator is provided with an elongated cylindrical bearing integral with the shaft of the actuator for increasing radial and moment load-carrying capacity of the actuator without increasing its length.
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Citations
8 Claims
- 1. A rotary actuator comprising a cylinder, a shaft rotatably mounted within said cylinder for relative rotation between the shaft and the cylinder, linear-to-rotary motion conversion means between the shaft and cylinder, said motion conversion means including a piston, means for selectively introducing pressurized fluid to alternative sides of said piston for reciprocating the piston and producing said relative rotation, and bearing means for carrying the radial and bending loads between the shaft and cylinder, said bearing means including a cylindrical bearing sleeve joined to said shaft extending along the length of the shaft inward of said cylinder, and spaced radially from the outer surface of the shaft to define an operating chamber for receiving the motion conversion means, and said bearing sleeve having a radially outer bearing surface in engagement with the inner surface of the cylinder.
- 5. An actuator comprising an outer cylinder, a shaft rotatably supported within the cylinder for relative rotational movement therebetween, a piston slidable in said cylinder, means for converting reciprocation of said pistion to rotary motion between said shaft and said cylinder, and hydraulic control means for guiding pressurized fluid into and out of said cylinder to opposite sides of said piston, said control means including axial passages in said shaft, radial main ports coupled to said passages and opening into said cylinder at opposite sides of the piston, said piston having a stroke which overlaps said ports at opposite extremes of movement whereby fluid discharging a port during movement of the piston becomes restricted in flow as the piston approaches an extreme of travel, said fluid control means including bypass ports adjacent each main port, said bypass ports being exposed to said cylinder in all positions of the piston movement, means in said bypass ports for allowing free flow when pressurizing the side of a piston for rapid initial movement of a piston from an extreme position, and means in said bypass ports for providing restricted flow of fluid discharging for providing hydraulic cushioning.
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7. A rotary actuator having an elongated cylinder, a shaft rotatably mounted in said cylinder, and reciprocating-to-rotary motion conversion means between the shaft and the cylinder, said motion conversion means including an independent ring gear fixed to said cylinder generally centrally of the axial length of the cylinder, said cylinder including an elongated, internal, smoothly finished surface, said shaft including an integral cylindrical bearing within said cylinder joined to said shaft and spaced radially therefrom, said motion conversion means including a piston coupled to a carrier that meshes with said ring gear wherein reciprocation of said piston will produce rotation of said shaft and cylinder relative to one another, said smoothly finished surface of said cylinder providing a seat for said cylindrical bearing, a seat for said ring and a seat for said piston.
Specification