Hydraulic device for human-powered vehicle

A hydraulic device for a human-powered vehicle, comprising:

• a base member including:
• a cylinder bore having an inner peripheral surface;
• and
• an annular groove provided on the inner peripheral surface, the annular groove including a first inner surface and a second inner surface, the first inner surface being spaced apart from the second inner surface in a first direction;
• a piston provided in the cylinder bore, the piston being movable relative to the base member from a rest position toward an actuated position in a second direction opposite to the first direction, the piston being movable relative to the base member from the actuated position toward the rest position in the first direction;
• a seal ring including a first axial surface facing in the first direction and a second axial surface facing in the second direction, the seal ring being provided in the annular groove so as to define a clearance between the first axial surface and the first inner surface;
• and
• an intermediate member provided in the clearance,
• the seal ring having a first axial length defined in the first direction,
• the intermediate member having a second axial length defined in the first direction,
• the second axial length being smaller than the first axial length, and
• a ratio of the second axial length to the first axial length ranging from 0.2 to 0.4.

A hydraulic device for a human-powered vehicle, comprising:

• a base member including:
• a cylinder bore having an inner peripheral surface;
• and
• an annular groove provided on the inner peripheral surface, the annular groove including a first inner surface and a second inner surface, the first inner surface being spaced apart from the second inner surface in a first direction;
• a piston provided in the cylinder bore, the piston being movable relative to the base member from a rest position toward an actuated position in a second direction opposite to the first direction, the piston being movable relative to the base member from the actuated position toward the rest position in the first direction;
• a seal ring including a first axial surface facing in the first direction and a second axial surface facing in the second direction, the seal ring being provided in the annular groove so as to define a clearance between the first axial surface and the first inner surface;
• and
• an intermediate member provided in the clearance,
• the intermediate member being integrally provided with the base member as a one-piece unitary member.

A hydraulic device for a human-powered vehicle, comprising:

• a base member including:
• a cylinder bore having an inner peripheral surface;
• and
• an annular groove provided on the inner peripheral surface, the annular groove including a first inner surface and a second inner surface, the first inner surface being spaced apart from the second inner surface in a first direction;
• a piston provided in the cylinder bore, the piston being movable relative to the base member from a rest position toward an actuated position in a second direction opposite to the first direction, the piston being movable relative to the base member from the actuated position toward the rest position in the first direction;
• a seal ring including a first axial surface facing in the first direction and a second axial surface facing in the second direction, the seal ring being provided in the annular groove so as to define a clearance between the first axial surface and the first inner surface;
• and
• an intermediate member provided in the clearance,
• the intermediate member including a plurality of intermediate parts arranged in a circumferential direction of the annular groove, and
• the plurality of intermediate parts being spaced apart from each other to define a plurality of spaces arranged in the circumferential direction.

A hydraulic device for a human-powered vehicle, comprising:

• a base member including:
• a cylinder bore having an inner peripheral surface;
• and
• an annular groove provided on the inner peripheral surface, the annular groove including a first inner surface and a second inner surface, the first inner surface being spaced apart from the second inner surface in a first direction;
• a piston provided in the cylinder bore, the piston being movable relative to the base member from a rest position toward an actuated position in a second direction opposite to the first direction, the piston being movable relative to the base member from the actuated position toward the rest position in the first direction;
• a seal ring including a first axial surface facing in the first direction and a second axial surface facing in the second direction, the seal ring being provided in the annular groove so as to define a clearance between the first axial surface and the first inner surface;
• and
• an intermediate member provided in the clearance,
• the annular groove including a third inner surface,
• the first inner surface being spaced apart from the third inner surface in the first direction,
• the third inner surface facing toward the first inner surface,
• the third inner surface being closer to the first inner surface than the second inner surface, and
• the third inner surface being configured to be in contact with the seal ring.