Motor and hydraulic pump device including the motor

A motor comprising:

• a piston (8) inserted in a cylinder hole (7) provided in a motor main body (4) so as to be movable in an axial direction of the cylinder hole (7);
• a first motor chamber (9) provided on a first end side in the axial direction relative to the piston (8);
• a second motor chamber (10) provided on a second end side in the axial direction relative to the piston (8);
• a supply/discharge valve (13) configured to switch between a state in which pressure fluid is discharged from the second motor chamber (10) and is supplied to the first motor chamber (9) and a state in which pressure fluid is discharged from the first motor chamber (9) and is supplied to the second motor chamber (10);
• a pressure supply chamber (28) provided on the second end side in the axial direction relative to the supply/discharge valve (13), the pressure supply chamber (28) being configured so that pressure fluid supplied to the pressure supply chamber (28) pushes and moves the supply/discharge valve (13) to a first position on the first end side in the axial direction;
• a switching actuation chamber (36) provided on the first end side in the axial direction relative to the supply/discharge valve (13), the switching actuation chamber (36) being configured so that pressure fluid supplied to the switching actuation chamber (36) pushes and moves the supply/discharge valve (13) to a second position on the second end side in the axial direction;
• and
• a pilot valve element (18) provided so as to protrude from the piston (8), the pilot valve element (18) being configured to switch between supplying and discharging pressure fluid to and from the switching actuation chamber (36) through movement of the pilot valve element (18) in the axial direction, wherein when the supply/discharge valve (13) is moved to the first position or to the second position, a first valve member (25) included in the supply/discharge valve (13) switches between supplying and discharging pressure fluid to and from the first motor chamber (9) and a second valve member (26) included in the supply/discharge valve (13) switches between supplying and discharging pressure fluid to and from the second motor chamber (10), and wherein
• the supply/discharge valve (13) is structured by a supply/discharge valve body (24), the first valve member (25), and the second valve member (26), which are unitary with one another.

A motor comprising:

• a piston (8) inserted in a cylinder hole (7) provided in a motor main body (4) so as to be movable in an axial direction of the cylinder hole (7);
• a first motor chamber (9) provided on a first end side in the axial direction relative to the piston (8);
• a second motor chamber (10) provided on a second end side in the axial direction relative to the piston (8);
• a supply/discharge valve (13) configured to switch between a state in which pressure fluid is discharged from the second motor chamber (10) and is supplied to the first motor chamber (9) and a state in which pressure fluid is discharged from the first motor chamber (9) and is supplied to the second motor chamber (10);
• a pressure supply chamber (28) provided on the second end side in the axial direction relative to the supply/discharge valve (13), the pressure supply chamber (28) being configured so that pressure fluid supplied to the pressure supply chamber (28) pushes and moves the supply/discharge valve (13) to a first position on the first end side in the axial direction;
• a switching actuation chamber (36) provided on the first end side in the axial direction relative to the supply/discharge valve (13), the switching actuation chamber (36) being configured so that pressure fluid supplied to the switching actuation chamber (36) pushes and moves the supply/discharge valve (13) to a second position on the second end side in the axial direction;
• and
• a pilot valve element (18) provided so as to protrude from the piston (8), the pilot valve element (18) being configured to switch between supplying and discharging pressure fluid to and from the switching actuation chamber (36) through movement of the pilot valve element (18) in the axial direction, wherein
• when the supply/discharge valve (13) is moved to the first position or to the second position, a first valve member (25) included in the supply/discharge valve (13) switches between supplying and discharging pressure fluid to and from the first motor chamber (9) and a second valve member (26) included in the supply/discharge valve (13) switches between supplying and discharging pressure fluid to and from the second motor chamber (10), and wherein
• the supply/discharge valve (13) comprises:
• a supply/discharge valve body (24);
• the first valve member (25) of a tubular shape, fitted over an outer peripheral wall of the supply/discharge valve body (24) so as to be movable in the axial direction, the first valve member (25) being configured to be biased by a first spring (39) toward the first end side in the axial direction and received from the first end side in the axial direction by a step portion (85) provided to the supply/discharge valve body (24);
• the second valve member (26) of a tubular shape, fitted over the outer peripheral wall of the supply/discharge valve body (24) so as to be movable in the axial direction, the second valve member (26) being configured to be biased by a second spring (40) toward the second end side in the axial direction;
• and
• a tubular transmission member (87) inserted between the first valve member (25) and the second valve member (26), the transmission member (87) being configured to receive the second valve member (26) from the second end side in the axial direction against a biasing force of the second spring (40).