Abstract: A hydraulic shock absorber includes a hollow cylinder which defines therein a fluid chamber filled with a working fluid, and a piston which is reciprocally disposed within the fluid chamber and divides the fluid chamber into upper and lower chambers. The piston is formed with fluid passages for establishing fluid communication between the upper and lower chambers. Each of the fluid passages is controlled by a disk valve assembly comprising a plurality of elastic disk plates, so as to introduce the working fluid from one of the upper and lower chambers to the other chamber when fluid pressure in one of the chambers is greater than a predetermined value. The disk valve assembly has a bypassing fluid passage which has a plurality orifices configured so as to gradually decrease fluid pressure and flow velocity of the working fluid passing therethrough.

Abstract: A rotary actuator is designed for rotatingly drive a rotary body, such as a rotary valve member for adjusting damping force to be created by a variable damping force shock absorber. The rotary actuator takes a layout of a permanent magnet and an electromagnet arranged in vertically spaced relationship. Vertical layout of the permanent magnet and the electromagnet reduces plane area required for installation.

Abstract: A shock absorber comprises a cylinder assembly defining a working chamber filled with a hydraulic working fluid and disposed therein a piston, and a fluid reservoir chamber filled with the hydraulic working fluid and a pneumatic working fluid, a communication path for connecting the working chamber and the fluid reservoir chamber for fluid communication therebetween, and a check and flow restriction assembly disposed within the communication path for selectively establishing and blocking fluid communication between the working chamber and the fluid reservoir chamber, the check and seal assembly includes a fluid check valve and a fluid flow restriction arranged in series, the flow restriction permitting pneumatic and hydraulic fluid flow directed to the fluid reservoir chamber during piston bounding stroke and providing flow restriction for the hydraulic fluid flow, and the check valve blocking fluid communication between the fluid reservoir chamber and the working chamber during piston rebounding stroke and p