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US 5,486,106 AGranted
Hydraulic device for supplying a hydraulic driving unit
OwnerKarl Hehlinventor
Life of this patent
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Abstract
In a hydraulic device a variable capacity pump adapted to record a differential pressure via a control valve is actuated in such a way that a constant operational pressure gradient is maintained. Since the variable capacity pump is driven by a rotary current motor, which is connected to a current source by a frequency converter and is regulable with regard to its speed, it is possible to control hydraulic consumers in an energy-saving manner at a reasonable price.
Claims5
A hydraulic device for supplying a hydraulic driving unit in an injection molding machine for processing synthetic materials comprising
- at least one variable capacity pump,
- a main line extending from said variable capacity pump to said driving unit,
- at least one control valve arranged in said main line and adapted to determine a quantity and a pressure of hydraulic fluid in said main line,
- a controlling mechanism connected with said variable capacity pump for control of said pressure,
- a control conduit which connects said controlling mechanism of said variable capacity pump with said main line downstream of said control valve,
- at least one pressure transducing means arranged for transducing an actual pressure value downstream of said control valve;
- comparing means for comparing said actual pressure value with a nominal pressure value and supplying a first correcting variable for said controlling mechanism in dependency of result of said comparing means,
- said variable capacity pump being driven by a rotary current motor which is connected to a current source, and a speed of rotation of said rotary current motors being regulated via a frequency converter arranged between said current source and said rotary current motor.
5 more elements
Dependencies are inferred from the claim text.