Liner retainer assembly

An assembly for releasing and securing a liner to a pump housing, comprising:

• a first member adapted to be connected to the housing and having an annular projecting portion forming a plurality of interconnected hydraulic chambers azmuthally spaced around said annular projecting portion;
• a second member disposed in each of said plurality of chambers of said first member and extending through apertures in a retainer member engaging the liner;
• a plurality of first biasing members, one of said first biasing members extending around each of said second members and engaging said first and second members to bias said second members and the liner in a first direction towards the housing to secure the liner to the housing;
• and
• said plurality of interconnected hydraulic chambers in said annular projecting portion hydraulically engaging said first and second members to bias said second members in a second direction away from the housing to relieve the bias of said first biasing members on said retainer member to unsecure said retainer member and the liner from the housing.

A liner retaining assembly comprising:

• a) a cylinder within which a liner is disposed, the cylinder having a first end and a second end;
• b) an annular piston disposed within the cylinder proximate the second end and being axially moveable within the cylinder, the piston further adapted to extend around a liner;
• c) means to secure the annular piston to a portion of the liner;
• and
• d) biasing means to urge the piston and a liner toward the first end of the cylinder, the biasing means applying a predetermined uniform prestress around the liner.

A method for securing a piston cylinder liner on a pump housing, the method comprising:

• a) disposing the liner within a cylinder to abut the pump housing;
• b) compressing a spring extending around the liner to store energy for uniformly biasing the liner against the pump housing;
• d) releasing the stored energy;
• and
• e) applying a uniform annular force around the liner to longitudinally compress the liner and urge it against the pump housing.