Hydraulic rotary screw machine with axial balancing piston

• US 4,131,400 A
• Filed: 04/19/1977
• Issued: 12/26/1978
• Est. Priority Date: 04/27/1976
• Status: Expired due to Term

• Current Assignee: ABet Imo-Industri
• Original Assignee: ABet Imo-Industri
• Inventors: Segerstrom, Lars
• Primary Examiner(s): Croyle, Carlton R.
• Assistant Examiner(s): Smith, Leonard E.
• Application Number:
  US05/788,968
• Time in Patent Office: 616 Days
• Field of Search: 418/197, 418/201, 418/203, 418/202
• US Class Current: 418/203
• CPC Class Codes: F01C 21/02 Arrangements of bearings bearing constructions F16C
• CPC Class Codes: F04C 15/0042 Systems for the equilibration of forces acting on the machines or pump interstice adjustment other than by fluid pressure F01C21/102

Abstract

A hydraulic screw machine having a housing employing a screw assembly with a drive screw and cooperating idler screws. The drive screw is sealably connected to a shaft extending beyond the housing on the high pressure side and has associated therewith a balance piston for acting on the screw drive. The drive screw is journalled to the shaft via bearings in the form of a self-adjusting plate surrounding the shaft. The plate is disposed between abutment surfaces connected to the housing for limiting its axial movement. A leakage channel between the piston and the housing is connected to the high pressure side of the machine and is determined by the balance piston.

Claims

1. A hydraulic screw machine comprising a housing, a drive screw extending axially of the housing;

a plurality of idler screws extending axially of the housing and intermeshing with said drive screw;

a shaft integral with said drive screw and protruding from one end of said housing;

means forming a shaft seal space about said shaft at said end of the housing, said shaft seal space being at a pressure lower than that of a high-pressure side of the machine;

a piston formed integral with a shaft of the drive screw, having an outer diameter equal to or smaller than the outer diameter of the drive screw, said piston extending with a close fit through a bore in the housing between the shaft-seal space and said high-pressure side;

a plate of greater diameter than the piston being affixed to said shaft at a side of the piston facing away from said drive screw;

a leak passage along the periphery of the piston;

said plate having a side facing away from the piston being subjected to pressure prevailing in said shaft seal space and the opposite side of the plate radially outwardly of the piston being subjected to a pressure intermediate the pressure prevailing in said shaft seal space and the pressure at said high-pressure side of said machine;

abutment means connected to said housing, facing radially outward portions of sais opposite sides of the plate and being adapted to confine said plate in an axial direction while permitting limited axial movement thereof between said abutment means.