Actuator
AssigneeBridgestone Corporation
InventorHiroyuki Kanesugi
Life of this patent
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Abstract
An object of the present disclosure is to provide an actuator having even better durability than the conventional actuator. Specifically, an actuator has an actuator main body constituted of a cylindrical tube capable of expanding/contracting by hydraulic pressure and a sleeve for covering an outer peripheral surface of the tube, the sleeve having a cylindrical structure formed by cords woven to be disposed in predetermined directions, wherein: the inner diameter r0 (mm) of the tube, the thickness t (mm) of the tube, the storage elastic modulus E′ (MPa) of the tube at 25° C., and the mesh aperture ratio A of the cords constituting the sleeve in a pressurized state satisfy the following formula (1): 50≤E′×(t/r0)/A≤600 (1).
Claims20
An actuator having an actuator main body constituted of a cylindrical tube capable of expanding/contracting by hydraulic pressure and a sleeve for covering an outer peripheral surface of the tube, the sleeve having a cylindrical structure formed by cords woven to be disposed in predetermined directions, wherein:
- the inner diameter r0 in mm of the tube, the thickness t mm of the tube, the storage elastic modulus E′ in MPa of the tube at 25° C., and the mesh aperture ratio A of the cords constituting the sleeve in a pressurized state satisfy the following formula (1):
- 60≤E′×(t/r0)/A≤200 (1)
- wherein said mesh aperture ratio (A) is a ratio (S2/S1) of the total area (S2) of clearances between the cords constituting the sleeve with respect to an area (S1) of an outer peripheral surface of the actuator main body,
- 0.005≤A≤0.06, and
- 10≤E′≤40.
Dependencies are inferred from the claim text.