Electric linear actuator assembly and method of assembly

Patent metadata

Field	Value
Publication number	US-9797943-B2
Application number	US-201313839659-A
Country	US
Kind code	B2
Filing date	Mar 15, 2013
Priority date	May 20, 2012
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

A method of constructing an electric linear displacement motor for use in a testing device includes providing a stator having as stator housing with internal coils and a through bore extending from a first end of the stator housing to the second end of the housing. First and second end supports are connected to the first and second ends of the stator housing. An armature having magnets retained therein is inserted into the stator housing such of the armature is supported by the first end support and the second end support. A plurality of set screws are inserted into threaded openings proximate both the first end and the second end of the housing. The set screws then support and retain the armature such that there is an annular gap between the armature and the coils.

First claim

What is claimed is:

1. An electric linear displacement motor for use in a testing apparatus, the electric linear displacement motor comprising:
a stator assembly comprising:
a stator housing having a first end and a second end and a through bore extending from the first end to the second end; and
a plurality of coils within the stator housing where each individual coil in the plurality of coils can be independently energized to create a desired electric field within the stator;

an armature assembly comprising:
an armature having an armature body with a first end and a second end, and a first outer diameter, and wherein the armature body includes a plurality of magnets along a length of the armature body;
a first end portion coupled to the first end of the armature body, the first end portion extending beyond the first end of the stator housing, wherein the first end portion has a first selected length and comprises a material different from a material of the armature body; and
a second end portion coupled to the second end of the armature body, the second end portion extending beyond the second end of the stator housing, wherein the second end portion has a second selected length and comprises the material different from the material of the armature body;
wherein the first and second end portions each comprise a second diameter greater than the first outer diameter of the armature body;

a first bearing assembly attached to the first end of the stator housing, the first bearing assembly comprising:
a first bearing housing configured to be attached to the first end of the stator housing; and
a first bearing positioned within the first bearing housing and wherein the first end portion engages and is carried by the first bearing and wherein the armature does not contact the first bearing; and

a second bearing assembly attached to the second end of the stator housing, the second bearing assembly comprising:
a second bearing housing configured to be attached to the second end of the stator housing; and
a second bearing positioned within the second bearing housing and wherein the second end portion engages and is carried by the second bearing and wherein the armature does not contact the second bearing.

2. The electric linear displacement motor of claim 1 and wherein the armature body comprises a cylindrical rod having the first outer diameter.

3. The electric linear displacement motor of claim 1 , wherein the material different from the material of the armature body is a magnetic material.

4. The electric linear displacement motor of claim 1 and wherein both the first and second bearing assemblies are beyond a magnetic field generated when the coils of the stator are energized and interact with the magnets.

5. The electric linear displacement motor of claim 1 and further comprising a plurality of fins extending from the stator housing.

6. The electric linear displacement motor of claim 1 and further comprising:
a load cell coupled to the second end portion; and
a specimen holder coupled to the load cell.

7. The electric linear displacement motor of claim 1 and wherein the first bearing assembly is removably attached to the first end of the stator with a first fastening mechanism.

8. The electric linear displacement motor of claim 7 and wherein the first fastening mechanism comprises:
a plurality of spaced apart, threaded apertures proximate the first end of the stator housing;
a plurality of spaced apart through bores in the first bearing housing configured to align with the plurality of spaced apart, threaded apertures proximate the first end of the stator housing; and
a plurality of set screws, each of the plurality of set screws configured to be positioned through one of the through bores in the first bearing housing and configured to threadably engage one of the plurality of spaced apart, threaded apertures proximate the first end of the stator housing such that the first bearing housing is removably securable to the stator housing through manipulation of the plurality of set screws.

9. The electric linear displacement motor of claim 8 and wherein the second bearing assembly is removably attached to the second end of the stator with a second fastening mechanism.

10. The electric linear displacement motor of claim 9 and wherein the second fastening mechanism comprises:
a plurality of spaced apart, threaded apertures proximate the second end of the stator housing;
a plurality of spaced apart through bores in the second bearing housing configured to align with the plurality of spaced apart, threaded apertures; and
a plurality of set screws, each of the plurality of set screws configured to be positioned through one of the through bores in the second bearing housing and configured to threadably engage one of the plurality of spaced apart, threaded apertures proximate the second end of the stator housing such that the second bearing housing is removably securable to the stator housing through manipulation of the plurality of set screws.

11. The electric linear displacement motor of claim 1 , wherein the armature body has a longitudinal length greater than a longitudinal length of the stator housing.

12. An electric linear displacement motor for use in a testing apparatus, the electric linear displacement motor comprising:
a stator assembly comprising:
a stator housing having a first end and a second end and a through bore extending from the first end to the second end; and
a plurality of coils within the stator housing where each individual coil in the plurality of coils can be independently energized to create a desired electric field within the stator;

an armature assembly comprising:
an armature body having a first end and a second end and wherein the armature body includes a plurality of magnets along a length of the armature body, the armature body having a longitudinal length greater than a longitudinal length of the stator housing;
a first end portion coupled to the first end of the armature body; and

a first bearing assembly removably attached to the first end of the stator housing, the first bearing assembly comprising:
a first bearing housing configured to be attached to the first end of the stator housing; and
a first bearing positioned within the first bearing housing and wherein the first end portion engages and is carried by the first bearing and wherein the armature body does not contact the first bearing.

13. An electric linear displacement motor for use in a testing apparatus, the electric linear displacement motor comprising:
a stator assembly comprising:
a stator housing having a first end and a second end and a through bore extending from the first end to the second end; and
a plurality of coils within the stator housing where each individual coil in the plurality of coils can be independently energized to create a desired electric field within the stator;

an armature assembly comprising:
an armature body having a first end and a second end and wherein the armature body includes a plurality of magnets along a length of the armature body;
a first end portion coupled to the first end of the armature body, wherein the first end portion comprises a material harder than a material of the armature body; and

a first bearing assembly removably attached to the first end of the stator housing, the first bearing assembly comprising:
a first bearing housing configured to be attached to the first end of the stator housing; and
a first bearing positioned within the first bearing housing and wherein the first end portion engages and is carried by the first bearing and wherein the armature body

Assignees

• Mts System Corp

Inventors

• Kuhlmann Tyler B
• Schulz Bradley Dean
• Krueger Paul M
• Petersen Don Curtis

Classifications

• Y10T29/49009

  Dynamoelectric machine · CPC title

• H02K15/14

  Casings; Enclosures; Supports · CPC title

• H02K15/16

  Centring rotors within the stators · CPC title

• H02K41/03 Primary

  Synchronous motors; Motors moving step by step; Reluctance motors (H02K41/035 takes precedence) · CPC title

• H02K5/00

  Casings; Enclosures; Supports · CPC title