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US 7,028,472 B2Granted
Pump unit
OwnerRyota Ohashi, Hironori Sumomozawainventors
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OwnerRyota Ohashi, Hironori Sumomozawainventors
Estimating the term…
The present invention provides a pump unit including at least one hydraulic pump with inlet and outlet ports, a pump case for accommodating the hydraulic pump having an opening through which the hydraulic pump is insertable, and a lid, called a center section, closing the pump case. The center section forms a pair of inlet/outlet passages communicating an end with the inlet and outlet ports of the hydraulic pump and an end opening through a pump case abutting surface of the center section, and a first charging passage by which hydraulic fluid is fed through the pump case abutting surface of the center section. At least one of the pump case and the center section communicates the first charging passage with the pair of inlet/outlet passages via a first hydraulic fluid feeding valve preventing the reverse flow into said first charging passage.
A pump unit for operation in association with first and second hydraulic motors that respectively drive first and second driving wheels comprising:
A pump unit for operation in association with first and second actuators comprising:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
Features relating to lubrication or cooling or heating: relating to lubrication supply, e.g. pumps; Pressure control
Details or component parts: housings
Having rotary cylinder block: having two or more sets of cylinders or pistons
By varying the relative positions of a swash plate and a cylinder block: by changing the inclination of the swash plate
Term ended 24 Aug 2020 (estimated)
The present invention relates to a pump unit used for various purposes.
More particularly, a first aspect of the present invention relates to a pump unit that includes a hydraulic pump, a pump case for accommodating the hydraulic pump and a center section connected to the pump case.
A hydraulic pump is used in various applications and in particular as the hydraulic pump adapted for operation in association with an actuator driven through the hydraulic effect. In this case, the hydraulic pump is connected to the actuator via a pair of hydraulic lines, and the output flow rate of hydraulic fluid discharged from the hydraulic pump is varied to cause the pressure difference between the pair of hydraulic lines, thereby driving the actuator. When the hydraulic pump is thus connected to the actuator via the pair of hydraulic lines so as to constitute a closed circuit, a charging mechanism is generally required to feed pressurized hydraulic fluid to the pair of hydraulic lines.
The above, and other objects, features and advantages of the present invention will become apparent from the detailed description thereof in conjunction with the accompanying drawings wherein.
FIG. 1 is an expansion plan view of a vehicle to which a pump unit according to first to fifth aspects of the present invention are applied.
FIG. 2 is a hydraulic circuit diagram of the vehicle to which one embodiment of a pump unit according to the first aspect of the present invention is applied.
First Embodiment
The first embodiment of the pump unit according to the first aspect of the present invention will be hereinafter described with reference to the accompanying drawings.
A pump unit 100 according to the first aspect of the present invention is designed to be operated in association with an actuator that is connected thereto via first and second pairs of hydraulic lines 184a and 184b and driven through an effect of pressurized hydraulic fluid in the pair of hydraulic lines. This embodiment will be described by taking for example the case that hydraulic motors 182a and 182b each are used as the actuator.