Vane type pump with a variable capacity for power steering devices
First Claim
1. A vane type pump with a variable capacity for a power steering device, comprising:
- a pump housing having an inlet port and an outlet port and defining a closed chamber therein, a part of said closed chamber being defined by a pair of flat end surfaces extending in parallel relation;
a movable member received in said closed chamber and guided by said pair of said flat end surfaces for movement in said closed chamber, said movable member having a cylindrical bore for dividing said closed chamber into a pressure chamber partly defined by an external surface of said movable member and a pump chamber partly defined by an internal surface of said cylindrical bore;
a drive shaft supported in said pump housing for rotation about an axis parallel to the axis of said cylindrical bore and having one end thereof extending into said pump chamber;
a rotor received in said pump chamber and connected with said one end of said drive shaft for integral rotation therewith, said rotor being formed with a plurality of radial slots at its circumferential surface;
a plurality of vanes respectively received in said plurality of radial slots and movable radially of said rotor and along said internal surface of said cylindrical bore;
urging means for urging said movable member to move in a radial direction of said rotor so as to deflect the axis of said movable member from the axis of said rotor;
a suction port formed on one of said pair of said flat end surfaces of said pump housing at a position opening to a first part of said pump chamber, said suction port communicating with said inlet port for conducting fluid to said first part of said pump chamber;
a discharge port formed on one of said pair of said flat end surfaces of said pump housing at a position opening to another part of said pump chamber and communicating with said pressure chamber for discharging pressurized fluid from said pump chamber to said pressure chamber;
sealing means forming a seal in a first part of said pressure chamber for cutting off a flow of pressurized fluid from said discharge port into said outlet port through said first part of said pressure chamber;
a valve element at another part of said pressure chamber which is opposite said sealing means in the radial direction of said rotor and is movable in said radial direction of said rotor, said valve element defining a throttle in cooperation with a part of said external surface of said movable member for dividing said pressure chamber into first and second pressure chamber portions respectively communicating with said discharge port and said outlet port, thereby generating a pressure difference between said first and second pressure chamber portions; and
a solenoid operated actuator secured to said pump housing and having a solenoid energized by an electric signal applied thereto for magnetically attracting said valve element so as to move said valve element in said radial direction of said rotor.
1 Assignment
0 Petitions
Accused Products
Abstract
A vane type pump with a variable capacity for power steering devices is provided with a movable ring received and radially movable in a closed cylindrical bore of a pump housing. A spring acts on the movable ring to deflect the axis of the movable ring from the axis of a rotor, which is rotated to move vanes along an internal bore of the movable ring. A sealing pin and a valve element are provided at diametrically opposite sides of the movable ring and define first and second pressure chambers around the movable ring. The first pressure chamber receives pressurized fluid from a part of the internal bore of the movable ring and conducts the pressurized fluid into the second pressure chamber through a throttle, which is defined by the valve element and a part of a circumferential external surface of the movable ring. The throttle generates a pressure difference between the first and second pressure chambers, and the pressure difference acts on the movable ring to move the same against the force of the spring. The pump is further provided with a solenoid operated actuator for adjusting the position of the valve element, and a relief valve.
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Citations
8 Claims
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1. A vane type pump with a variable capacity for a power steering device, comprising:
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a pump housing having an inlet port and an outlet port and defining a closed chamber therein, a part of said closed chamber being defined by a pair of flat end surfaces extending in parallel relation; a movable member received in said closed chamber and guided by said pair of said flat end surfaces for movement in said closed chamber, said movable member having a cylindrical bore for dividing said closed chamber into a pressure chamber partly defined by an external surface of said movable member and a pump chamber partly defined by an internal surface of said cylindrical bore; a drive shaft supported in said pump housing for rotation about an axis parallel to the axis of said cylindrical bore and having one end thereof extending into said pump chamber; a rotor received in said pump chamber and connected with said one end of said drive shaft for integral rotation therewith, said rotor being formed with a plurality of radial slots at its circumferential surface; a plurality of vanes respectively received in said plurality of radial slots and movable radially of said rotor and along said internal surface of said cylindrical bore; urging means for urging said movable member to move in a radial direction of said rotor so as to deflect the axis of said movable member from the axis of said rotor; a suction port formed on one of said pair of said flat end surfaces of said pump housing at a position opening to a first part of said pump chamber, said suction port communicating with said inlet port for conducting fluid to said first part of said pump chamber; a discharge port formed on one of said pair of said flat end surfaces of said pump housing at a position opening to another part of said pump chamber and communicating with said pressure chamber for discharging pressurized fluid from said pump chamber to said pressure chamber; sealing means forming a seal in a first part of said pressure chamber for cutting off a flow of pressurized fluid from said discharge port into said outlet port through said first part of said pressure chamber; a valve element at another part of said pressure chamber which is opposite said sealing means in the radial direction of said rotor and is movable in said radial direction of said rotor, said valve element defining a throttle in cooperation with a part of said external surface of said movable member for dividing said pressure chamber into first and second pressure chamber portions respectively communicating with said discharge port and said outlet port, thereby generating a pressure difference between said first and second pressure chamber portions; and a solenoid operated actuator secured to said pump housing and having a solenoid energized by an electric signal applied thereto for magnetically attracting said valve element so as to move said valve element in said radial direction of said rotor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification