Abstract:
A motor includes a rotor module and a stator module. The rotor module includes electro-active polymer modules which change their physical size depending on electrical activation or deactivation. The stator module includes a base and a plurality of magnets mounted on two fixing plates of the base. The rotor module comprises a rotor and a coil. Precise displacement by the motor is obtained by electrically activating or deactivating the electro-active polymer modules.

Description:
FIELD 
     The subject matter herein generally relates to motors. 
     BACKGROUND 
     Generally, a feedback circuit is utilized to stop a motor. However, inertia remains in a moving rotor of the motor and the rotor of the motor will not immediately stop. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Implementations of the present technology will now be described, by way of example only, with reference to the attached figures. 
         FIG. 1  is an isometric view of a first embodiment of a motor in the present disclosure. 
         FIG. 2  is an isometric view of the motor in  FIG. 1  but viewed from a different angle. 
         FIG. 3  is an exploded, isometric view of the motor in  FIG. 1 . 
         FIG. 4  is a cross-sectional view of the motor along line IV-IV of  FIG. 1 . 
         FIG. 5  is a cross-sectional view of the motor along line V-V of  FIG. 1 . 
         FIG. 6  is a cross-sectional view of the motor in  FIG. 1  in operation. 
         FIG. 7  is a cross-sectional view of a second embodiment of a motor. 
         FIG. 8  is a cross-sectional view of a third embodiment of a motor. 
         FIG. 9  is a cross-sectional view of a fourth embodiment of a motor. 
     
    
    
     DETAILED DESCRIPTION 
     It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts have been exaggerated to better illustrate details and features of the present disclosure. 
     Several definitions that apply throughout this disclosure will now be presented. 
     The term “outside” refers to a region that is beyond the outermost confines of a physical object. The term “substantially” is defined to be essentially conforming to the particular dimension, shape, or other feature that the term modifies, such that the component need not be exact. For example, “substantially cylindrical” means that the object resembles a cylinder, but can have one or more deviations from a true cylinder. The term “comprising,” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series and the like. 
     The present disclosure is described in relation to a chassis assembly. 
     Referring to  FIG. 1 , a motor  100  of a first embodiment includes a stator module  10 , a rotor module  30 , and an electro-active polymer module  50 . The electronactive polymer module  50  is mounted on the rotor module  30 . In the embodiment, the motor  100  is a U-shaped linear motor. The electro-active polymer module  50  is made of polyvinylidene fluoride (PVDF) or ion-exchange polymer metal composite (IPMC). The stator module  10  includes a base  11  and a plurality of magnetic dipoles  13 . The base  11  is U-shaped. 
     Referring to  FIG. 2 , the base  11  includes a substrate  111  and two fixing plates  113 . The substrate  111  and the fixing plates  113  are rectangular plates. The two fixing plates  113  extend from the substrate  111 . The two fixing plates  113  include a first inner surface  150  and a second inner surface  160 . The base  11  can be made of stainless steel. 
     The plurality of magnetic dipoles  13  are uniformly mounted on the first inner surface  150  and the second inner surface  160 . Each of the magnetic dipoles  13  includes two magnets  131 . The two magnets  131  are parallel and oppositely mounted on the first inner surface  150  and the second inner surface  160  of the two fixing plates  113 . A plurality of magnets  131  is mounted on each of the first inner surface  150  and the second inner surface  160  of the fixing plates  113 . Each of the two neighboring magnets  131  presents an opposite polarity to the other. A magnetic track  130  is defined by the two fixing plates  113  and the magnets  131  mounted on the first inner surface  150  and the second inner surface  160  of the two fixing plates  113 . 
     Referring to  FIG. 3 , the rotor module  30  includes a rotor  31  and a coil  33 . The coil  33  is a three-phase coil and electrically connected to an outside power source (not shown). The rotor module  30  with the rotor  31  includes a sliding part  311  and a fixing part  313 . The sliding part  311  is planar. The coil  33  is mounted on the sliding part  311 . The sliding part  311  is inserted in the magnetic track  130 . The rotor module  30  has a first outer surface  170  and a second outer surface  180  opposite, and substantially parallel to the first outer surface  170 . A portion of the rotor module  30  is inserted within the stator module  10  with an inserted portion of the first outer surface  170  facing the first inner surface  150  and an inserted portion of the second outer surface  180  facing the second inner surface  160 . 
     The fixing part  313  is U-shaped and is configured for carrying an object to be moved by the motor  100 . A U-shaped opening  3131  is defined in the fixing part  313 . A side of the sliding part  311  is inserted in the U-shaped opening  3131  of the fixing part  313 . An electro-active polymer module  50  is mounted on the first outer surface  170  and the second outer surface  180  of the sliding part  311 . When the electro-active polymer module  50  is electrically activated, the volume of the electro-active polymer module  50  is reduced. When the electro-active polymer module  50  is deactivated, the volume of the electro-active polymer module  50  expands to 380% of original volume. When the electro-active polymer module  50  is not activated, the surfaces of the sliding part  311  which carries the electro-active polymer module  50  is expanded and contacts the plurality of the magnets  131 . The electro-active polymer module  50  can be electrically connected to the power source or to the coil  33 . 
     Referring to  FIG. 4 , in assembly, the magnetic dipoles  13  are mounted on the fixing plates  113  of the base  11 . The electro-active polymer modules  50  are mounted on opposite sides (the first outer surface  170  and the second outer surface  180 ) of the sliding part  311  of the rotor module  31 . The sliding part  311  which carries the electro-active polymer module  50  is inserted in the magnetic track  130 . The sliding part  311  is between two magnets  131  of the dipoles  13 . 
     Referring to  FIG. 5  and  FIG. 6 , in operation, an object (not shown) is mounted on the fixing part  313 . The coil  33  of the rotor module  31  is connected to electrical power and the electro-active polymer module  50  is activated. The rotor module  31  slides along the magnetic track  130 . 
     When the sliding part  311  of the rotor module  31  is in a predetermined position in the magnetic track  130 , the electro-active polymer module  50  is deactivated and the volume of electro-active polymer module  50  expands to 380% of the original volume, thus the electro-active polymer module  50  contacts the magnets  131  of the fixing plates  113 . The rotor module  31  thus stops immediately and precisely because of frictional force between the electro-active polymer module  50  and the magnets  131 . 
     Referring to  FIG. 7 , a motor  100  of the second embodiment of the present disclosure is different from the motor  100  of the first embodiment in that the electro-active polymer module  50  is mounted on the plurality of magnetic dipoles  13 . When the motor  100  is in operation, the electro-active polymer module  50  is activated and the rotor module  31  slides along the magnetic track  130 . When the electro-active polymer module  50  is deactivated, the electro-active polymer module expands to make contact with the rotor  31  causing the rotor  31  to immediately stop. 
     Referring to  FIG. 8 , a motor  100  of a third embodiment in the present disclosure is different from the motor  100  of the first embodiment in that the motor  100  of the third embodiment in the present disclosure does not include magnetic dipoles  13 . The motor  100  of the third embodiment includes two coils  15 . A coil  15  is mounted on each of the two fixing plates  113  of the base  11 . The rotor module  30  only includes a rotor  31 . The sliding part  311  of the rotor  31  is made of permanent magnets. The rotor module  31  does not include a  3 -phase coil. The electro-active polymer module  50  is mounted on the coil  15  of the two fixing plates  113 . 
     Referring to  FIG. 9 , a motor  100  of a fourth embodiment of the present disclosure differs from the motor  100  of the first embodiment in that the motor  100  of the fourth embodiment does not include magnetic dipoles  13 . The coils  15  are mounted on the fixing plates  113  of the base  11 . The rotor module  30  only includes the rotor  31 . The sliding part  311  of the rotor  31  is a permanent magnet and does not includes a coil. The electro-active polymer modules  50  are mounted on the two sides of the sliding part  311  of the rotor  31 . When the motor  100  is in operation, the electro-active polymer module  50  is activated and the rotor module  31  slides along the magnetic track  130 . When the electro-active polymer module  50  is deactivated, the electro-active polymer module expands to make contact with the coils  15  causing the rotor  31  to immediately stop. 
     In all the above embodiments, the motor  100  is a motor and the electro-active polymer module  50  is made of PVDF or IPMC. 
     The embodiments shown and described above are only examples. Many details are often found in the art such as the other features of a precise-motion motor. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, especially in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the embodiments described above may be modified within the scope of the claims.