초록 ▼

An intensifier unit includes a pair of sequentially operated reciprocating ram assemblies, each powered by a cylinder motor. Extension of the cylinder rods is accomplished by application of pressurized hydraulic fluid to the pistons. The pistons are returned quicker than they are extended by means o

An intensifier unit includes a pair of sequentially operated reciprocating ram assemblies, each powered by a cylinder motor. Extension of the cylinder rods is accomplished by application of pressurized hydraulic fluid to the pistons. The pistons are returned quicker than they are extended by means of continuous application of pressurized air to the back side of the pistons. The cylinder motors are precompressed prior to their respective forward strokes by means of an accumulator which continuously bleeds from the main hydraulic fluid supply line. Circuitry is provided to insure that precompression continues even if the ram and its driving piston move from their retracted position. Also disclosed is a safety interlock to shut down the intensifier if both cylinder rods become accidentally simultaneously extended.

대표청구항 ▼

In a hydraulic intensifier for oil well fracturing, erosion drilling or the like, in which a pair of working rams are sequentially operated by a corresponding pair of hydraulic cylinder motors from a source of hydraulic fluid under high pressure and in which said motors move between retracted and ex

In a hydraulic intensifier for oil well fracturing, erosion drilling or the like, in which a pair of working rams are sequentially operated by a corresponding pair of hydraulic cylinder motors from a source of hydraulic fluid under high pressure and in which said motors move between retracted and extended positions, the improvement comprising: first valve means for applying hydraulic fluid from said source selectively to said cylinder motors for causing extending movement thereof and a corresponding working stroke of the ram associated therewith, accumulator means connected to said source through means defining a restricted orifice to bleed off a portion of the output of said source, second valve means responsive to the return of each of said cylinder motors to their corresponding retracted positions for connecting said motors to said accumulator means for precompressing said motors prior to the initiation of the direct application of hydraulic fluid from said source, means responsive to the arrival of each of said cylinder motors toward their respective extended positions for applying hydraulic fluid from said source to the other motor which has been precompressed in its retracted position, so that the output pressure of the intensifier remains essentially uninterrupted, means for depressurizing each said cylinder motor at its extended position upon the direct application of said source to the other motor, and means for returning each said depressurized cylinder motor from itS extended position to its retracted position at a rate which exceeds the rate at which said motors move from their respective retracted positions to their extended positions.