Motor and hydraulic pump device including the motor

Patent metadata

Field	Value
Publication number	US-12066022-B2
Application number	US-202017633724-A
Country	US
Kind code	B2
Filing date	Jul 31, 2020
Priority date	Aug 9, 2019
Publication date	Aug 20, 2024
Grant date	Aug 20, 2024

Abstract

A piston ( 8 ) is provided in a motor main body ( 4 ). A first motor chamber ( 9 ) is provided above the piston ( 8 ) and a second motor chamber ( 10 ) is provided below the piston ( 8 ). A pilot valve element ( 18 ) is provided so as to protrude from the piston ( 8 ). When a supply/discharge valve ( 13 ) is moved to its upper limit position or its lower limit position by the movement of the pilot valve element ( 18 ) in an up-down direction, a first valve member ( 25 ) of 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 ) of the supply/discharge valve ( 13 ) switches between supplying and discharging pressure fluid to and from the second motor chamber ( 10 ).

First claim

The invention claimed is:

1. 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 protrusion ( 27 ) protruding from the outer peripheral wall of the supply/discharge valve body ( 24 ) outward in a radial direction of the supply/discharge valve body ( 24 ); and
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 received by the protrusion ( 27 ) from the second end side in the axial direction.

2. The motor according to claim 1 , wherein
an auxiliary spring ( 38 , 81 ) is attached on the first or second end side in the axial direction relative to the supply/discharge valve ( 13 ), and the auxiliary spring ( 38 , 81 ) biases the supply/discharge valve ( 13 ) toward the second or first end side in the axial direction.

3. The motor according to claim 1 , wherein
the second motor chamber ( 10 ) is communicatively connected to the switching actuation chamber ( 36 ) by a passage ( 78 ), and a throttle passage ( 79 ) is provided at a part of or all over the passage ( 78 ).

4. The motor according to claim 1 , further comprising:
a first working chamber ( 29 ) in which the first valve member ( 25 ) is disposed, the first working chamber ( 29 ) being communicatively connected to the pressure supply chamber ( 28 );
a second working chamber ( 31 ) in which the second valve member ( 26 ) is disposed, the second working chamber ( 31 ) being communicatively connected to the pressure supply chamber ( 28 ); and
a pressure discharge chamber ( 34 ) communicatively connected to the first working chamber ( 29 ) and to the second working chamber ( 31 ), the pressure discharge chamber ( 34 ) being provided between the first working chamber ( 29 ) and the second working chamber ( 31 ), wherein
the first working chamber ( 29 ), the pressure discharge chamber ( 34 ), and the second working chamber ( 31 ) are arranged in the axial direction.

5. A hydraulic pump device comprising: the motor recited in claim 1 ; and a pump ( 3 ) configured to be driven by the motor, the device further comprising:
a plunger ( 22 ) connected to the piston ( 8 ) and inserted in the pump ( 3 ) so as to be movable in the axial direction, the plunger ( 22 ) including a large-diameter portion ( 60 );
a first pump chamber ( 61 ) provided on the first end side in the axial direction relative to the large-diameter portion ( 60 );
a second pump chamber ( 62 ) provided on the second end side in the axial direction relative to the large-diameter portion ( 60 );
a first inlet valve ( 65 ) provided to a first inlet passage ( 63 a ) which communicatively connects an inlet port ( 63 ) of hydraulic oil to the first pump chamber ( 61 ), the first inlet valve ( 65 ) being configured to allow a flow of hydraulic oil from the inlet port ( 63 ) to the first pump chamber ( 61 ) and to block the reverse flow;
a second inlet valve ( 66 ) provided to a second inlet passage ( 63 b ) which communicatively connects the inlet port ( 63 ) to the second pump chamber ( 62 ), the second inlet valve ( 66 ) being configured to allow a flow of hydraulic oil from the inlet port ( 63 ) to the second pump chamber ( 62 ) and to block the reverse flow;
a first outlet valve ( 67 ) provided to a first outlet passage ( 64 a ) which communicatively connects the first pump chamber ( 61 ) to an outlet port ( 64 ) of pressurized oil, the first outlet valve ( 67 ) being configured to allow a flow of hydraulic oil from the first pump chamber ( 61 ) to the outlet port ( 64 ) and to block the reverse flow; and
a second outlet valve ( 68 ) provided to a second outlet passage ( 64 b ) which communicatively connects the second pump chamber ( 62 ) to the outlet port ( 64 ) of hydraulic oil, the second outlet valve ( 68 ) being configured to allow a flow of hydraulic oil from the second pump chamber ( 62 ) to the outlet port ( 64 ) and to block the reverse flow.

6. The hydraulic pump device according to claim 5 , wherein
the plunger ( 22 ) comprises: a first small-diameter portion ( 22 a ) connected to the piston ( 8 ); the large-diameter portion ( 60 ) having a diameter larger than the diameter of the first small-diameter portion ( 22 a ) and connected to the first small-diameter portion ( 22 a ); and a second small-diameter portion ( 22 b ) having a diameter substantially equal to the diameter of the first small-diameter portion ( 22 a ) and connected to the large-diameter portion ( 60 ).

7. 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

Assignees

• Kosmek Ltd

Inventors

• Yonezawa Keitaro
• Okubo Yoshiki

Classifications

• F04B9/129

  having plural pumping chambers · CPC title

• F01B23/08

  Adaptations for driving, or combinations with, pumps · CPC title

• F15B15/18

  Combined units comprising both motor and pump · CPC title

• F15B2211/20576

  with multiple pumps · CPC title

• F04B9/133 Primary

  reciprocating movement of the pumping members being obtained by a double-acting elastic-fluid motor · CPC title