Stator especially adapted for use in a helicoidal pump/motor and method of making same

Abstract

A method of making a stator for a helicoidal pump/motor formed by a network of fibers encapsulated in an elastomer. The core is formed by laying up elastomeric preforms into helical grooves formed in a mandrel and wrapping an elastomeric sheet around helical projections formed in the mandrel. Successive strips of calendered rubber/wire cloth are then laid up into the grooves so as to fill the grooves, which are then wrapped in another layer of calendered rubber/wire cloth. The assembly is then filament wound with reinforcing cords and compression cured so as to bond the elastomeric components into a unitary element. The assembly is then placed in the stator housing and additional elastomer injected into the annular passage between the stator housing and the assembly. The completed assembly is then further cured so that the injected and previously cured elastomers bond to form a unitary structure having good strength and heat transfer capabilities.

What is claimed:  
     
         1 . A method of making a stator for a helicoidal fluid handling device suitable for use as a positive displacement pump or motor, said stator comprising an elastomeric form having an inner surface, first portions of said elastomeric form forming a number of grooves in said inner surface extending helically along the length of said stator, second portions of said elastomeric form forming a projection on said inner surface between each of said grooves, said projections extending helically along the length of said stator, comprising the steps of: 
 a) providing a mandrel having a helical groove for each of said stator projections, each of said helical grooves having a contour substantially matching that of its respective projection;    b) forming a plurality of layers of fiber networks each of which is encapsulated by an elastomer;    c) laying up successive adjacent layers of elastomeric elements into said mandrel grooves so as to at least partially fill said grooves, at least a portion of said layers comprising said said layers of elastomeric encapsulated fiber networks;    d) curing said layers under compression so that said elastomer in each of said layers bonds to said elastomer in adjacent layers.    
     
     
         2 . The method according to  claim 1 , further comprising the steps of: 
 e) enclosing said cured layers, while maintained on said mandrel, in a stator housing so as to form an annular passage therebetween;    f) injecting additional elastomer into said annular passage;    g) curing said injected elastomer so as to bond said injected elastomer to said previously cured layers.    
     
     
         3 . A stator for a helicoidal fluid handling device suitable for use as a positive displacement pump or motor, said stator comprising an elastomeric form having an inner surface, said inner surface forming a number of grooves extending helically along the length of said stator, said elastomeric form comprising a network of fibers encapsulated in an elastomeric material.