Modular stator for tubular electric linear motor and method of manufacture

Abstract

A modular design for and method of constructing long stators for tubular electric linear motors having many sets of coils. In certain embodiments, the stator is made by assembling a multiplicity of identical coil modules which are combined to form a stator of whatever length may be required. In some embodiments, coil modules containing the coils are connected by intermediate connectors. In those embodiments, the sum of the effective length of the coil module and the effective length of the intermediate connector must be an integral multiple of the pole pitch of the magnets in the motor's mover. In some embodiments, longitudinal grooves are formed in the coil modules to provide paths for coolant.

1 . A stator for a tubular linear motor, comprising:
 a plurality of electrically interconnected identical coil modules, each coil module comprising:
 a plurality of coils, and 
 a plurality of externally accessible electrical connectors for electrically interconnecting at least two coil modules. 
   
     
     
         2 . The stator of  claim 1 , wherein there are a set of said electrical connectors on each end of said coil module. 
     
     
         3 . The stator of  claim 1 , wherein said coil modules are interconnected by intermediate connectors which electrically connect a set of electrical connectors on one coil module with a corresponding set of electrical connectors on another coil module. 
     
     
         4 . The stator of  claim 3 , wherein the sum of the effective length of one of said coil modules and the effective length of one of said intermediate connectors is an integer multiple of the pole pitch of the magnets on the mover. 
     
     
         5 . The stator of  claim 1 , wherein the effective length of each coil module is an integer multiple of the pole pitch of the magnets on the mover. 
     
     
         6 . The stator of  claim 5 , wherein each coil module further comprises a set of male connectors at one end and a set of female connectors at the other end. 
     
     
         7 . The stator of  claim 6 , wherein each coil module further comprises a set of pad connectors at each end of the module. 
     
     
         8 . The stator of  claim 1 , wherein the number of coils in each of said coil modules is a multiple of three. 
     
     
         9 . The stator of  claim 1  wherein the interconnected modules are surrounded by a cylindrical housing. 
     
     
         10 . A stator for a tubular linear motor, comprising:
 a plurality of electrically interconnected identical coil modules, each coil module comprising:
 a plurality of coils, 
 a plurality of metal comb shaped elements, each of said comb shaped elements comprising a longitudinal spine and a plurality of teeth, whereby the spines of said metal comb shaped elements are distributed about the circumference of the coils and the teeth are located between adjacent coils, and 
 a set of externally accessible electrical connections at each end of each of said coil modules, and 
   a cylindrical housing surrounding said coil modules.   
     
     
         11 . The stator of  claim 10  wherein each of said comb shaped elements has a laminated structure. 
     
     
         12 . The stator of  claim 10 , wherein
 said stator is powered by three phase current and   the number of coils in the module is an integer multiple of three.   
     
     
         13 . The stator of  claim 10 , wherein there is a coolant path between the spines of adjacent pairs of comb shaped elements. 
     
     
         14 . A stator for a tubular linear motor, comprising:
 a plurality of electrically interconnected identical coil modules, each coil module comprising a plurality of coils arranged in adjacent pairs,
 wherein one coil of each of said pairs of coils is wound in the opposite direction as the other coil of the pair. 
   
     
     
         15 . The stator of  claim 14 ,
 wherein said stator is powered by three phase current and   the two coils in said adjacent pairs of coils are powered by the same phase of the three phase current.   
     
     
         16 . The stator of  claim 15 , wherein the number of coils in the module is an integer multiple of six. 
     
     
         17 . A tubular linear motor, comprising:
 the stator of  claim 1 , and   a mover.   
     
     
         18 . A tubular linear motor, comprising:
 the stator of  claim 10 , and   a mover.   
     
     
         19 . A tubular linear motor, comprising:
 the stator of  claim 14 , and   a mover.   
     
     
         20 . A method of manufacturing a stator for a tubular linear motor, comprising:
 interconnecting a plurality of coil modules, each coil module comprising:
 a plurality of coils, and 
 a plurality of externally accessible electrical connectors for electrically interconnecting at least two coil modules, and 
   inserting said interconnected coil modules into a cylindrical housing.   
     
     
         21 . A method of manufacturing a stator for a tubular linear motor, comprising:
 interconnecting a plurality of coil modules, each coil module comprising:
 a plurality of coils, 
 a plurality of metal comb shaped elements, each of said comb shaped elements comprising a longitudinal spine and a plurality of teeth, whereby the spines of said metal comb shaped elements are distributed about the circumference of the coils and the teeth are located between adjacent coils, and 
 a set of externally accessible electrical connectors at each end of each of said coil modules, and 
   inserting said interconnected coil modules into a cylindrical housing.   
     
     
         22 . The method of manufacturing a stator for a tubular linear motor of  claim 21 , wherein said coil modules are interconnected by intermediate connectors which electrically connect a set of electrical connectors on one coil module with a corresponding set of electrical connectors on another coil module. 
     
     
         23 . A method of manufacturing a coil module for a stator for a tubular linear motor powered by three phase current, comprising:
 placing a plurality of bobbins and spacers on a winding mandrel;   winding said plurality of bobbins with a single length of wire to form a set of coils;   interleaving three sets of said coils on an encapsulation mandrel;   distributing a plurality of metal comb shaped elements, each of said comb shaped elements comprising a longitudinal spine and a plurality of teeth, about the circumference of said interleaved sets of coils;   surrounding said interleaved sets of coils and said metal comb shaped elements with an encapsulation mold;   encapsulating said interleaved sets of coils and said metal comb shaped elements;   removing the encapsulated coil module from said mold and said encapsulation mandrel.