Abstract: A valve seat member is provided with: a first seat arranged so as to be spaced apart from an opening of a port; a second seat connected to the first seat at both ends so as to surround the opening of the port; an island portion arranged on the first seat side of the opening of the port in a region surrounded by the first seat and the second seat such that a hollow space is formed between the island portion and the first seat; and a passage configured to extend through the island portion to allow communication between the port and the hollow space.

Abstract: A shock absorber includes a bearing unit having a bearing and a bearing holding member, and a seal unit having a seal member and a seal holding member. The seal holding member includes a seal accommodating portion being configured to accommodate the seal member, and an insertion hole through which a piston rod is inserted. The seal member is pressed against an outer circumferential surface of the piston rod and the seal accommodating portion by working-fluid pressure in the extension-side chamber. And the bearing is provided such that a first end surface of the bearing facing the seal member matches an aperture plane of a through hole of the bearing holding member or such that the first end surface of the bearing projects out from the aperture plane of the through hole.

Abstract: A shock absorber includes a bearing unit having a bearing and a bearing holding member, and a seal unit having a seal member and a seal holding member. The seal holding member includes a seal accommodating portion being configured to accommodate the seal member, and an insertion hole through which a piston rod is inserted. The seal member is pressed against an outer circumferential surface of the piston rod and the seal accommodating portion by working-fluid pressure in the extension-side chamber. And the bearing is provided such that a first end surface of the bearing facing the seal member matches an aperture plane of a through hole of the bearing holding member or such that the first end surface of the bearing projects out from the aperture plane of the through hole.

Abstract: A valve seat member is provided with: a first seat arranged so as to be spaced apart from an opening of a port; a second seat connected to the first seat at both ends so as to surround the opening of the port; an island portion arranged on the first seat side of the opening of the port in a region surrounded by the first seat and the second seat such that a hollow space is formed between the island portion and the first seat; and a passage configured to extend through the island portion to allow communication between the port and the hollow space.