Patent Publication Number: US-11641148-B2

Title: Actuator, electric motor and associated method

Description:
BACKGROUND OF THE INVENTION 
     The embodiments described herein relate generally to an electric machine, and more specifically, to an electric machine with a switch activated or deactivated when a rotational speed is obtained. 
     An electric machine is typically in the form of an electric generator or an electric motor. The machine typically has a centrally located shaft that rotates relative to the machine. Electrical energy applied to coils within the machine initiates this relative motion which transfers the power to the shaft and, alternatively, mechanical energy from the relative motion of the generator excites electrical energy into the coils. For expediency, the machine will be described hereinafter as a motor. It should be appreciated that a machine may operate as a generator and vice versa. 
     A stationary assembly, also referred to as a stator, includes a stator core and coils or windings positioned around portions of the stator core. It is these coils to which energy is applied to initiate this relative motion which transfers the power to the shaft. These coils are formed by winding wire, typically copper, aluminum or a combination thereof, about a central core to form the winding or coil. An electric current is directed through the coils which induces a magnetic field. It is the magnetic field that initiates this relative motion which transfers the power to the shaft. 
     For a variety of reasons an electrical machine may have a centrifugal switch that is used to either electrically engage or electrically disengage a circuit when a certain rotational speed is obtained. Such switches typically have a mechanical component or components that are urged radially outward by centrifugal forces that increase as the rotational speed increase. The centrifugal forces move contacts in the electrical circuit either into engagement or disengagement when the rotational speed reaches a certain level. The mechanical components that move the contacts are expensive and are subject to mechanical wear. 
     One such centrifugal switch is used in induction motors to disengage the start winding once the motor has obtained a sufficiently high rotational speed that the run windings can properly power the motor. Such a sufficient motor speed may be, for example about 70% of the maximum motor speed. 
     The present invention is directed to alleviate at least some of these problems with the prior art. 
     BRIEF DESCRIPTION OF THE INVENTION 
     A switch according to the present invention may be used in an electric machine that is typically in the form of an electric generator or an electric motor. The motor includes a housing and a centrally located rotor that rotates relative to and is secured to the housing. The motor also includes a stator secured to the housing. The stator includes a plurality of spaced apart teeth extending inwardly. The stator also includes wire formed into a plurality of coils, each of the plurality of coils wrapped around one of the plurality of teeth. 
     For example, the motor may be in the form of an induction, capacitive start, motor. The motor includes a first set of coils that is used to operate the motor in a run mode and a second set of coils that is electrically connected to a start capacitor that is used to operate the motor in a start mode. Once the motor reaches 70% of the motor maximum speed, the start coils are deenergized with, for example, an electrical device or switch, for example, the centrifugal switch of the present invention. 
     According to an aspect of the present invention, an electrical switch for use in an electric machine may include a first member securable to the rotor and rotatable with the rotor. The switch may also include a second member slidably securable to the body and configured to be moveable with respect to the first member in a direction parallel to the axis of rotation of the rotor. The first member and the second member are either magnetically attracted toward or magnetically repelled from each other. 
     The switch may also include a first electrically conductive member cooperable with the second member and moveable in a direction parallel to the axis of rotation of the rotor from a first axial position to a second axial position, spaced from the first axial position. The second member may be adapted to urge the first electrically conductive member from the first axial position to the second axial position. 
     The switch may also include a second electrically conductive member spaced from the first electrically conductive member when the first electrically conductive member is in the first axial position and electrically engaged with the first electrically conductive member when the first electrically conductive member is in the second axial position. The first member may have a least a portion thereof having a center of mass moveable from a first radial distance from the axis of rotation of the rotor when the rotor rotates at a first rotational speed to a second radial distance from the axis of rotation of the rotor when the rotor rotates at a second rotational speed different than the first rotational speed. The second radial distance is different than the first radial distance. 
     Magnetic attraction or magnetic repulsion may cause the first member and the second member to be either magnetically attracted toward each other or magnetically repelled away from each other to cause to cause the second member to either engage and disengage the first electrically conductive member with the second electrically conductive member when the rotor reaches the second rotational speed. 
     According to an aspect of the invention, the electrical switch may be configured such that the first member and the second member are magnetically repelled by each other. 
     According to another aspect of the invention, the electrical switch may be configured such that at least one of a portion of the first member and a portion of the second member includes a magnet. 
     According to another aspect of the invention, the electrical switch may be configured such that the first member includes a base fixedly secured to the end of the rotor, an arm having an end extending from the base at least partially in a direction parallel to the axis of rotation of the rotor, and one of a magnet and a ferrous material connected to the end of the arm and spaced from the base. 
     According to another aspect of the invention. the electrical switch may be configured such that the first member includes a plurality of spaced apart arms, each arm having a first end thereof and one of a magnet and a ferrous material connected to the first end of each of the plurality of arms. 
     According to another aspect of the invention, the electrical switch may be configured such that wherein each of the spaced apart arms are equally spaced apart with respect to the axis of rotation of the rotor. 
     According to another aspect of the invention, the electrical switch may be configured such that the second member includes a first component fixedly secured to the body a second component slidably secured to the first component, and one of a magnet and a ferrous material secured to the second component. 
     According to another aspect of the invention, the electrical switch may be configured such that the first component includes a cylindrical sleeve; and wherein the second component includes a cylindrical rod. 
     According to another aspect of the invention, the electrical switch may be configured such that the first electrically conductive member includes a resilient metal having a first end connected to the body and a second cantilevered end engagable with the second member and wherein the second electrically conductive member includes a resilient metal having a first end connected to the body and a second cantilevered end engagable with the first electrically conductive member. 
     According another aspect of the invention, the electrical switch may be configured such that the first member includes a first component including a base fixedly secured to the end of the rotor, first and second legs, each leg extending at least partially axially outwardly from one of the distal ends of the planar base and first and second planar arms extending at least partially radially inwardly from the distal ends of the legs, one of a magnet and a ferrous material connected to the first arm, and the other of one of a magnet and a ferrous material connected to the second arm. 
     According to another aspect of the invention, the electrical switch may be configured such that the ferrous material is permanently magnetized. 
     According to another aspect of the invention, the electrical switch may be configured such that the first component is made from a plurality of individual members, wherein the first arm is connected to the first leg by a mechanical hinge, and further including a spring connected to the first leg and to the second arm, the spring adapted to permit the first arm to move outwardly about the hinge when the rotor is rotated. 
     According to another aspect of the invention, the electrical switch may be configured such that the first member includes a first member magnet; and further including a third member including a third member magnet, the third member connected to the first member, the third member magnet positioned farther than first member magnet from the second member. 
     According to another aspect of the invention. the electrical switch may be configured such that the first member includes an integral metal component having a planar base fixedly secured to the end of the rotor, first and second planar legs, each leg extending at least partially axially outwardly from one of the distal ends of the planar base and first and second planar arms extending at least partially radially inwardly from the distal ends of the planar legs, a first magnet connected to the first arm, and a second magnet connected to the second arm. 
     According to another aspect of the invention. the electrical switch may further include a third magnet positioned on the planar base of the component. 
     According to another aspect of the invention, the electrical switch may be configured such that the first member includes a plurality of spaced apart arcuate magnet portions spaced from the axis of rotation of the rotor and wherein the second member has a centerline parallel to and spaced from the axis of rotation of the rotor. 
     According to an aspect of the invention, an electric machine may be provided. The machine includes a housing, a stator and a rotor. The housing has an inner surface defining a cavity therein. The stator is secured to the housing. The rotor is rotatably secured to the housing and defines an axis of rotation thereof. The machine also includes a centrifugal switch including a first member securable to the rotor and rotatable therewith and a second member slidably securable to the body and configured to be moveable with respect to the first member in a direction parallel to the axis of rotation of the rotor. The first member and the second member are one of magnetically attracted toward or magnetically repelled from each other. The machine also includes a first electrically conductive member cooperable with the second member moveable in a direction parallel to the axis of rotation of the rotor from a first axial position to a second axial position, spaced from the first axial position. The second member is adapted to urge the first electrically conductive member from the first axial position to the second axial position. 
     The machine also includes a second electrically conductive member spaced from the first electrically conductive member when the first electrically conductive member is in the first axial position and electrically engaged with the first electrically conductive member when the first electrically conductive member is in the second axial position. 
     The first member has a least a portion thereof having a center of mass moveable from a first radial distance from the axis of rotation of the rotor when the rotor rotates at a first rotational speed to a second radial distance from the axis of rotation of the rotor when the rotor rotates at a second rotational speed different than the first rotational speed. The second radial distance is different than the first radial distance. 
     One of the of magnetic attraction and the magnetic repulsion causes the first member and the second member to be one of magnetically attracted toward each other or magnetically repelled away from each other to cause to cause the second member to one of engage and disengage the first electrically conductive member with the second electrically conductive member when the rotor reaches the second rotational speed. 
     According to another aspect of the invention, the electrical machine may be configured such that the first member and the second member are magnetically repelled by each other. 
     According to an aspect of the invention the electrical machine may be configured such that at least one of a portion of the first member and a portion of the second member includes a magnet. 
     According to an aspect of the invention a method for transmitting an electrical signal in an electric machine once a certain rotation speed has been obtained is provided. The method includes the steps of providing a housing, securing a stator to the housing, and rotatably securing a rotor to the housing. The rotor defines an axis of rotation thereof. 
     The method also includes the steps of providing a centrifugal switch, securing a first member to the rotor, and slidably securing a second member to the housing. 
     The method also includes the steps of configuring the second member to be moveable with respect to the first member in a direction parallel to the axis of rotation of the rotor, adapting the first member and the second member to be one of magnetically attracted toward or magnetically repelled from each other, and providing a first electrically conductive member. 
     The method also includes the steps of using the second member to selectively move the first electrically conductive member from the first axial position to the second axial position, providing a second electrically conductive member spaced from the first electrically conductive member when the first electrically conductive member is in the first axial position, and electrically engaging with the first electrically conductive member to the second electrically conductive member when the first electrically conductive member is in the second axial position. 
     The method includes the steps of providing a portion of the first member having a center of mass moveable from a first radial distance from the axis of rotation of the rotor when the rotor rotates at a first rotational speed to a second radial distance from the axis of rotation of the rotor when the rotor rotates at a second rotational speed different than the first rotational speed, the second radial distance being different than the first radial distance. 
     The method also includes the steps of utilizing one of the of magnetic attraction and the magnetic repulsion to cause one of the first member and the second member to be one of magnetically attracted toward each other or magnetically repelled away from each other to cause the second member to engage the first electrically conductive member with the second electrically conductive member when the rotor reaches one of the first rotational speed and the second rotational speed. The inner cavity is generally cylindrical and wherein the moisture guide is generally planar. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view partially in cross-section of an electric motor according to an embodiment of the present invention; 
         FIG.  2    is partial perspective view of the electric device of  FIG.  2    of an electric device according to an embodiment of the present invention installed in the electric motor of  FIG.  1    with the motor with the motor at a first or zero rotational speed and with the device in a first state; 
         FIG.  3    is partial perspective view of the electric device of  FIG.  2    with the motor at a second or third rotational speed, faster than the first rotational speed and with the device in a second state; 
         FIG.  3 A  is partial plan view of the electric device of  FIG.  2    showing the first member base in a first rotational speed position in solid lines, in a second rotational speed position in dashed lines and in a third rotational speed position in phantom lines; 
         FIG.  4    is partial perspective view of a magnet and bracket assembly for use in the electric device of  FIG.  3    with the lower magnets close together to urge the upper magnet upwardly; 
         FIG.  5    is partial perspective view of the magnet and bracket assembly of  FIG.  3    with the lower magnets moved apart by centrifugal force to permit the upper magnet to move downwardly; 
         FIG.  6    is a partial perspective view of a magnet and bracket assembly according to another embodiment of the present invention utilizing semi cylindrically shaped magnets; 
         FIG.  7    is a partial perspective view of a magnet and bracket assembly according to another embodiment of the present invention utilizing rectangularly shaped magnets; 
         FIG.  8    is a partial perspective view of a magnet and bracket assembly according to another embodiment of the present invention utilizing three cylindrically shaped magnets; 
         FIG.  9    is a partial perspective view of a magnet and bracket assembly according to another embodiment of the present invention utilizing four cylindrically shaped magnets; 
         FIG.  10    is a partial perspective view of a magnet and bracket assembly according to another embodiment of the present invention utilizing two cylindrically shaped magnets on the bracket and two cylindrically shaped magnets centrally positioned to cooperate with the magnets on the bracket; 
         FIG.  11    is a partial perspective view of a magnet and bracket assembly according to another embodiment of the present invention utilizing two cylindrically shaped magnets on the bracket and a third cylindrically shaped magnet centrally positioned, and configured to have the magnets attract each other when cooperating with each other, 
         FIG.  12    is a partial perspective view of a magnet and bracket assembly according to another embodiment of the present invention utilizing a hollow cylindrical magnet, made from 6 magnet sectors on the bracket and an offset cylindrically shaped magnet to cooperate with the magnets on the bracket; and 
         FIG.  13    is a partial plan view of a magnet and bracket assembly according to another embodiment of the present invention utilizing a mechanical hinge and spring to urge the magnets together when centrifugal forces are low; and 
         FIG.  14 A  is a first part of three parts of a flow chart of another embodiment of the present invention in the form of a method for providing an electric device; 
         FIG.  14 B  is a second part of three parts of a flow chart of another embodiment of the present invention in the form of a method for providing an electric device; and 
         FIG.  14 C  is a third part of three parts of a flow chart of another embodiment of the present invention in the form of a method for providing an electric device. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG.  1   , an electric machine  10  for which a switch according to the present invention may used is shown. The electric machine  10  is typically in the form of an electric generator or an electric motor. For expediency the machine  10  will be described hereinafter as a motor  10 . It should be appreciated that a motor may operate as a generator and vice versa. The electric machine or motor  10  includes a housing  12 . The housing  12  has an inner surface defining a cavity  14  therein. 
     Typically, the motor  10  includes a centrally located shaft  16  that rotates relative to the housing  12 . The electric machine also includes a rotor  18 . Typically, and as shown in  FIG.  1   , the rotor  18  includes the shaft  16  to which a load, not shown, is typically directly or indirectly secured. As shown, the rotor  18  is rotatably secured to the housing  12 . 
     As shown in  FIG.  1   , the motor  10  includes a stator  20  secured to the housing  12 . The stator  20  includes a stator body  22  that has a generally circular outer periphery  24  and a generally circular inner periphery  26 , spaced from the outer periphery  24 . 
     While the body  22  may be made of various suitable materials, may be unitary or made from multiple components, as shown in  FIG.  1   , typically, the body  22  is made from a plurality of sheets or laminations  28 . The laminations  28  are typically made of a magnetically conductive material, for example, of a ferrous material or a magnetically conductive composite. Each of the laminations  28  includes a plurality of spaced apart teeth  30  extending inwardly from the circular inner periphery  26 . 
     The stator  20  also includes wire  39  formed into a plurality of coils  34 , each of the plurality of coils  34  is wrapped around one of the plurality of teeth  30 . 
     Note that the above description of the motor  10  is for a radial flux motor. It should be appreciated that the actuator of the present invention may be utilized with an axial flux motor with or without a rotor shaft. Such an axial flux motor is more fully described in U.S. Pat. No. 3,568,978 A, hereby incorporated in its entirety by reference. 
     For the induction, capacitive start, motor  10 , the motor includes a first set  32  of coils  34  that is used to operate the motor in a run mode and a second set  36  of coils  34  that are electrically connected to a start capacitor  38  that is used to operate the motor in a start mode. Once the motor reaches 70% of the motor maximum speed, the start coils are deenergized with, for example, the centrifugal switch of the present invention. 
     According to an aspect of the present invention and referring now to  FIG.  2   , an electrical switch  40  for use in electric machine  10  may include a first member  42  securable to the rotor  18  and rotatable with the rotor  18 . The switch  40  may also include a second member  44  slidably securable to the housing  12  and configured to be moveable with respect to the first member  42  in a direction parallel to axis of rotation  19  of the rotor  18 . The first member  42  and the second member  44  are either magnetically attracted toward or magnetically repelled from each other. 
     As shown in  FIG.  2   , The first member  42  nay be attached to the rotor  18 . As shown in  FIG.  2   , the first member  42  is attached to an end  46  of the shaft  16 . The first member  42 , as shown, may be attached along axis of rotation  19 . Placing the first member along the axis  19  minimizes any out of balance forces on the rotating rotor  18 . 
     To further minimize any out of balance forces on the rotating rotor  18 , the first member has first member centerline  21  which is preferably coincident with the axis of rotation  19  of rotor  18 . 
     The first member may be secured to the shaft  16  and/or rotor  18  by a centrally located screw  48  attached by internal threads  49  formed in shaft  16 . Alternatively, the first member may be secured by welding, adhesives or by an interference fit to shaft or rotor. 
     To provide the magnetic attraction or repulsion, the first member  42  or the second member  44 , or both, may include a magnet which provides for the magnetic attraction or repulsion. The magnet may be permanent magnet. The magnet may be a ferrite magnet or a rare earth magnet, including, for example a neodymium magnet. 
     As shown in  FIG.  2   , the first member  42  may have any shape and be made of any suitable materials capable of being securable to the rotor  18  and rotatable with the rotor  18 . 
     The first member  42 , as shown in  FIG.  2   , may have a portion thereof in the form of a first member magnet  50 . 
     It should be appreciated that the first member magnet  42  may be in the form of a unitary magnet, a cluster of adjacent magnets or a group of spaced apart magnets. 
     Note that the first member  42  may alternatively not include a magnet, but only a ferrous material and the second member  44  would then include a magnet that cooperates with the ferrous material of the first member  42 . 
     The first member magnet  50  may be permanent magnet. The first member magnet  50  may be a ferrite magnet or a rare earth magnet, including, for example a neodymium magnet. 
     The first member magnet  50  may have any suitable shape. For example, the first magnet may be cylindrical, rectangular, square, polygon or any other regular or irregular shape. As shown in  FIG.  2   , the first member magnet  50  is cylindrical. 
     As shown in  FIG.  2   , the first member  42  may include a base  52  for supporting the first member magnet  50 . The base  52  may be integral with the magnet  50  or be made of a different material. 
     As shown and according to an aspect of the invention the base  52  may be made of a resilient material. The resilient material may be, for example, a metal, a polymer or a composite. The base  52  may include a mounting portion  54  for mounting the base  52  onto the shaft  16  or the rotor  18 . As shown in  FIG.  2   , the base may include one or more arms  56  extending from the mounting portion  54 . 
     Referring now to  FIG.  3 A , the first member magnet  50  has a center of mass  58  moveable from a first radial distance FRD from the axis of rotation  19  of the rotor  18  when the rotor  18  rotates at a first rotational speed FRS to a second radial distance SRD from the axis of rotation  19  of the rotor  18  when the rotor  18  rotates at a second rotational speed SRS different than the first rotational speed FRS. For example and as shown in  FIG.  3 A , the first radial distance FRD may occur when the first rotational speed FRS is a zero rotational speed ZRS. 
     To have the center of mass  58  move and according to an aspect of the invention, the base  52  is resilient so that the centrifugal force of the first member magnet  50  urges the magnet  50  radially outwardly an increasing distance from the axis of rotation  19  of the rotor  18  as the rotational speed of the rotor increases. 
     For example and as is shown in  FIG.  3 A , the arm  56  and the mounting portion  54  may be made of a resilient material such that when the rotor  18  is stationary or at the first rotational speed FRS or at the zero rotational speed ZRS, the arm  56  and the mounting portion  54  are in a stationary or first rotational speed position  60  as shown in solid. 
     As the rotor  18  begins to rotate and angularly accelerate, the centrifugal forces on the first member  42  cause the center of mass  58  to move from first radial distance FRD from axis of rotation  19  of rotor  18  at the first rotational position  60  to second radial distance SRD from axis of rotation  19  of rotor  18  at second rotational speed position  62  as shown in dashed lines when the rotor obtains a second rotational speed SRS. 
     As the rotor  18  continues to rotate and angularly accelerate, the centrifugal forces on the first member  42  cause the center of mass  58  to move from second radial distance SRD from axis of rotation  19  of rotor  18  at second speed position  62  to third radial distance TRD from axis of rotation  19  at third rotational speed position  64  as shown in phantom lines when the rotor  18  obtains a third rotational speed TRS. 
     According to an aspect of the invention, once the rotor  18  obtains the third rotational speed TRS, the first member  42  cooperates with the second member  44  to either magnetically attract or magnetically repel each other. This magnetic attraction or magnetic repulsion causes the electrical switch  40  of the present invention to be tripped. 
     For the magnetic repulsion shown in  FIGS.  1 - 5   , the tripping at the third rotational speed position  64  is a tripping of a circuit that become “open” or prohibits electricity to be conducted. For example, the tripping can occur when third rotational speed TRS is 70% of the maximum rotor speed. At that 70% of the maximum rotor speed the second set or starter coil set  36  may be deenergized by the tripping of electrical switch  40  or prohibiting electricity to be conducted to the second set or starter coil set  36 . 
     It should be appreciated that the third rotational speed TRS may be any percentage of the maximum rotor speed and that the obtaining of the third rotational speed TRS may trip the electrical switch  40  to accomplish any desired change to the motor, for example to remove power from the motor once a maximum rotor speed is exceeded. 
     It should be appreciated that the first member  42  may be configured to flex or move to permit the changing of the distance from the center of mass of the magnet  50  to the axis of rotation  19  of rotor  18  by any shape or configuration possible to permit this flexing. For example, the mounting portion  54  may be generally rigidly positioned on shaft  16  by the screw  48  connected to the shaft  16 . The arm  56  may flex and/or a living hinge  65  between the arm  56  and the mounting portion  54  may flex to permit the required movement of the magnet  50 . The living hinge  65  may have the same thickness as the arm  56  or the mounting portion  54  or may have a thinner thickness to provide for most of the flexing in the living hinge  65 . 
     As shown in  FIGS.  1 - 5   , the switch  40  may also include the second member  44  slidably securable to the housing  12  and is configured to be moveable with respect to the first member  42  in a direction parallel to axis of rotation  19  of the rotor  18 . As the center of mass  58  of the first member magnet  50  decrease its distance from the axis of rotation  19  of rotor  18 , the first member magnet  50  becomes radially closer to the second member  44 . 
     It should be appreciated that the first member  42  and the second member  44  may either repel each other or attract each other. The switch  40  of  FIGS.  1 - 5    utilizes the first member  42  that repels the second member  44 . 
     The second member  44  as shown in  FIGS.  3 - 5    includes a second member magnet  66 . It should be appreciated that the second member magnet  66  may be in the form of a unitary magnet, a cluster of adjacent magnets or a group of spaced apart magnets. 
     It should be appreciated that the present invention may be practiced with only a first member magnet or a second member magnet with the other member having a ferrous material that may attract or repel the other member. 
     As shown in  FIG.  3 A , the second member  44  is movable along a path as shown by arrows  67  constrained by, for example, a stem  68  secured to the housing  12 . This movement can be accomplished by any suitable mechanism providing the restrained path. 
     As shown in  FIG.  3 A , the first member  42  urges the second member  44  upwardly into stationary or upward position  55  as shown in solid when the rotor  18  is stationary. The actuator  40  also includes a downward urging device  53  to urge the second member  44  downwardly to trip position when the rotor  18  rotates sufficiently to trip the actuator  40 . When the rotor  18  is stationary the magnetic repulsion force between the first member  42  and the second member  44  is greater than the force of the downward urging device  53  so that the second member  44  is in stationary or upward position  55 . When the rotor  18  rotates sufficiently to trip the actuator  40 , the magnetic repulsion force between the first member  42  and the second member  44  is less than the force of the downward urging device  53  so that the second member  44  is in trip or downward position  57 , as shown in dashed lines. 
     The downward urging device  53  may be a spring, a sponge or gravity. The downward urging device  53  for the actuator  40  of  FIGS.  1 - 5    is in the form of a first electrically conductive member  69 , which will be discussed in greater detail below. 
     For example and as shown in  FIG.  3 A , the stem  68  is mounted to housing  12  and extends in axis  63  that may, as shown, be coincident with the axis of rotation  19  of rotor  18 . It should be appreciated that the present invention may be practiced with the stem extending in a direction skewed to the axis of rotation  19  or in a direction parallel and spaced from the axis of rotation  19  of rotor  18 . 
     As shown in  FIG.  3 A  as the first member  42  and first member magnet  50  moves from first rotational position  60  to first position  62  and eventually to second position  64 , the magnetic repulsion between the first member  42  and the second member  44  become less than the force of the downward urging device  53  which causes the second member  44  to advance downwardly in the direction of arrows  67  along stem  68 . The second member  44  may have a central opening  45  which mates with the periphery of the stem  68 . The central opening  45  may be cylindrical or any other suitable shape. a cylindrical sleeve; and wherein the second component includes a cylindrical rod. 
     The motion of second member  44  downwardly provides the actuation force for the actuator or switch  40  of the present invention. As shown in  FIG.  3 A , the switch  40  may also include the first electrically conductive member  69  that cooperates with the second member  44 . The first electrically conductive member  69  moves in a direction at least partially parallel to the axis  19  of rotation of the rotor  18  from a first axial position  70  as shown in solid to a second axial position  71  as shown in phantom, spaced from the first axial position  70 . 
     The first electrically conductive member  69  may be biased downwardly toward second position  71 , so that the movement downwardly of the second member  44  permits the electrically conductive member  69  to move from the first axial position  70  to the second axial position  71 . As stated above the first electrically conductive member  69  serves as the downward urging device  53 . The magnetic repulsion between the first member  42  and the second member  44  is less than the downwardly urging first electrically conductive member  69 , causing the first electrically conductive member  69  to move downwardly. In the first axial position, the first member  42  and the second member  44  are spaced apart and do not contact each other, and the first member magnets  50  are spaced apart and do not contact each other. In the second axial position, the first  42  and the second member  44  are spaced apart and do not contact each other, and the first member magnets  50  are spaced apart and do not contact each other. 
     Continuing to refer to  FIG.  3 A , the switch  40  may also include a second electrically conductive member  72  electrically engaged with the first electrically conductive member  69  when the first electrically conductive member  69  is in the first axial position  70  and electrically disengaged with the first electrically conductive member  69  when the first electrically conductive member  69  is in the second axial position  71 . 
     When the second electrically conductive member  72  is electrically disengaged from the first electrically conductive member  69 , the switch  40  may be tripped. The switch  40  is electrically connected to an electric circuit  73  to affect the operation of the motor  10 . This energizing or tripping may cause the electric motor  10  to operate differently. For example, for the motor  10  if it is a capacitive start induction motor, the tripping may occur when FRS is 70% of the maximum rotor speed and the circuit  73  may be tripped to disconnect power to the second set  36  of coils  34  and may cause the second set  36  of coils  34  or starter coils to be deenergized. 
     The first electrically conductive member  69  and the second electrically conductive member  72  may have suitable size and shape and may be made of any suitable materials. The first and second members  69  and  72  may be made of copper, aluminum or a composite material. The first and second members  69  and  72  may have first and second contact portions  74  and  75 , respectively, for engaging each other. The contact portions may be flat curved, concave and convex, or have any other suitable configuration. 
     As shown in  FIG.  3 A , the first electrically conductive member  69  may be in the form of an electrically conductive plate or bar extending in a cantilevered fashion from the housing  12  of motor  10 . As shown the housing  12  of motor  10  may include an end cap  76  to which the member  69  is secured. As shown the member  69  extends from end cap  76  in a direction transverse to axis of rotation  19  of rotor  18 . The first electrically conductive member  69  may be resilient such that it may be moveable from first axial position  70  to second axial position  71 . The member  69  may have a contact portion made of a different or identical material and may have a shape conducive to good electrical conductance from the first member  69  to the second member  72 . The first electrically conductive member  69  has a distal portion  77  that engages second member  44 . 
     As shown in  FIG.  3 A , the second electrically conductive member  72  may be in the form of an electrically conductive plate or bar extending in a cantilevered fashion from the end cap  76  to which the member  72  is secured. As shown the member  72  extends from end cap  76  in a direction transverse to axis of rotation  19  of rotor  18 . 
     The second electrically conductive member  72  may be resilient, but may be rigid as the first electrically conductive member  69  is moveable toward the second electrically conductive member  72 . The member  72  may have a contact portion made of a different or identical material and may have a shape conducive to good electrical conductance from the first member  69  to the second member  72 . 
     As shown in  FIG.  3 A , the contact portion  75  of the first electrically conductive member  70  and the contact portion  76  of the second electrically conductive member  71  may have convex mating surfaces to provide for an electric contact that will have no or minimal arcing as the switch  40  is actuated. 
     It should be appreciated that the position of the stem, the strength of the downward urging device, the upward position  55  and the downward position  57  of the second member, the first rotational position  60  and the second rotational speed position  64  of the first member, the size and magnetic strength of the first member and the second member  44 , as well as the dimensions of the first member base  52 , may be modified to obtain the desired tripping or actuation for the actuator  40 . 
     It should be appreciated that the position of the first member and/or that of the second member may be made adjustable so that the trip or actuation speed of the actuator of the present invention may be fine-tuned or adjusted for different motor applications. For example, the magnet may have an eccentric stem (not shown) that may be rotated to adjust magnet position, or the first member base may provide for adjustable magnet mounting (not shown) or for adjustment to arm length or arm flexibility (not shown). 
     Referring now to  FIG.  4   , the first member  42 , the first member magnet  50 , the first member base  52  and the second member  44  are shown in the first rotational position  60 . 
     Referring now to  FIG.  5   , the first member  42 , the first member magnet  50 , the first member base  52  and the second member  44  are shown in the second rotational speed position  64 . 
     While the actuator  40  of  FIGS.  1 - 5    has a pair of spaced apart first members  42 , it should be appreciated that the actuator of the present invention may be provided with a solitary first member. The use of a plurality of first member spaced evenly about the center of rotation of the motor rotor may provide for smoother operation and for lower bearing loads and fewer balancing and vibration issues. Such problems with a solitary first member need to be balanced against the lower cost of a solitary first member. 
     According to another aspect of the invention and referring now to  FIG.  6   , electrical switch  140  is shown. Switch  140  is similar to switch  40  of  FIGS.  1 - 5   , except first member  142  includes a pair of spaced apart first member magnets  150  that are semi-cylindrically shaped. Each of the magnets  150  are connected to an arm  156  of base  152 . Flat surfaces  147  of the magnets  150  are positioned adjacent to each other. 
     According to another aspect of the invention and referring now to  FIG.  7   , electrical switch  240  is shown. Switch  240  is similar to switch  40  of  FIGS.  1 - 5   , except first member  242  includes a pair of spaced apart first member magnets  250  that are rectangularly shaped. Each of the magnets  250  are connected to an arm  256  of base  252 . Flat surfaces  247  of the magnets  250  are positioned adjacent to each other. 
     According to another aspect of the invention and referring now to  FIG.  8   , electrical switch  340  is shown. Switch  340  is similar to switch  40  of  FIGS.  1 - 5   , except first member  342  includes three equally of spaced apart first member magnets  350  that are cylindrically shaped. Each of the magnets  250  are connected to one of three arms  356  of base  352 . 
     According to another aspect of the invention and referring now to  FIG.  9   , electrical switch  440  is shown. Switch  440  is similar to switch  40  of  FIGS.  1 - 5   , except first member  442  includes four equally of spaced apart first member magnets  450  that are cylindrically shaped. Each of the magnets  450  are connected to one of four arms  456  of base  452 . 
     According to another aspect of the invention and referring now to  FIG.  10   , electrical switch  540  is shown. Switch  540  is similar to switch  40  of  FIGS.  1 - 5   , except first member  542  includes two equally of spaced apart first member magnets  550  that are cylindrically shaped. Each of the magnets  550  are connected to one of the two arms  556  of base  552 . Second member  544  with a second member magnet  566  is slidably fitted to housing  512  at stem  568  of second member  544 . 
     An additional magnet  580  is secured by screw  548  to shaft  516  and to first member base  552 . The additional magnet  580  may be used to attract or repel the second member magnet  566 . The additional magnet  580  may provide for more “snap” or more aggressive movement of the first electrically conductive member to the second electrically conductive member to reduce arcing and to prolong the life of the actuator. Note that additional magnet(s) may be position at other locations in the motor, particularly in the first member base to improve this “snap” action. Also, the strength and positioning of the magnets may be adjusted to improve this “snap” action. 
     According to another aspect of the invention and referring now to  FIG.  11   , electrical switch  640  is shown. Switch  640  is similar to switch  40  of  FIGS.  1 - 5   , except that switch  640  using the magnetic attraction of the first member  642  to the second member  644  to actuate the switch  640 . The first member  642  includes two equally of spaced apart first member magnets  650  that are cylindrically shaped. Each of the magnets  650  are connected to one of the two arms  656  of base  652 . Second member  644  with a second member magnet  666  is slidably fitted to housing  612  at stem  668  of second member  644 . The second member magnet  666  is positioned below the two first member magnets  650 . 
     When in the stationary or zero rotational speed position  660  as shown, the two first member magnets  650  urge second member magnet  666  and the second member  644  upwardly to connect the first electrically conductive member to the second electrically conductive member. As arms  656  of the first member base  652  move outwardly as the rotor  618  rotates, the first member magnets  650  provide less upward magnetic attraction to the second member magnet  666 , letting the second member  644  move downwardly permitting the first electrically conductive member to disconnect from the second electrically conductive member. 
     According to another aspect of the invention and referring now to  FIG.  12   , electrical switch  740  is shown. Switch  740  is similar to switch  40  of  FIGS.  1 - 5   , except first member  742  includes a plurality of spaced apart first member magnet segments  750  that are arch shaped. Each of the magnets magnet segments  750  are positioned at a radial distance RD from centerline  781  of base  752 . Second member  744  with a second member magnet  766  is slidably fitted to housing  712  at stem  768  of second member  744 . The stem  768  is positioned on stem centerline  782  parallel to axis of rotation  719  of rotor  718 . The centerline is spaced radial distance RDD from axis of rotation  719  of rotor  718 . Centerline  781  of base  752  may be coincident with axis of rotation  719  of rotor  718 . 
     According to another aspect of the invention and referring now to  FIGS.  13 - 14   , electrical switch  840  is shown. Switch  840  is similar to switch  40  of  FIGS.  1 - 5   , except first member  842  includes a pair of spaced apart first member magnets  850  that are mounted to first member base  852 . The magnets  850  are each mounted to one of a plurality of arms  856 . 
     The first member base  852  is made from a plurality of individual members. The first member base  852  includes first member mounting plate  884  which is secured to rotor  818 . The first member base  852  also includes the spaced apart arms  856  that are connected to first member mounting plate  884  by mechanical hinges  886 . The arms  856  are urged inwardly by a spring  888 . The spring  888  is connected to the arms  856 . 
     The spring  888  is adapted to permit the arms  856  to move outwardly about the hinge when the rotor  818  is rotated. As the arms  856  move outward as the rotor continues to rotationally accelerate, the first member magnets  850  move away from second member magnet  866  connected to second member  844  that is slidably fitted to housing  812  and moves downwardly permitting the first electrically conductive member to disconnect from the second electrically conductive member. 
     According to an aspect of the invention a method  900  for transmitting an electrical signal in an electric machine once a certain rotation speed has been obtained is provided. The method includes step  910  of providing a housing, step  912  of securing a stator to the housing, and step  914  of rotatably securing a rotor to the housing. The rotor defines an axis of rotation thereof. 
     The method also includes step  916  of providing a centrifugal switch, step  918  of securing a first member to the rotor, and step  920  of slidably securing a second member to the housing. 
     The method also includes the step  922  of configuring the second member to be moveable with respect to the first member in a direction parallel to the axis of rotation of the rotor, step  924  of adapting of the first member and the second member to be one of magnetically attracted toward or magnetically repelled from each other, and step  926  of providing a first electrically conductive member. 
     The method also includes the step  928  of using the second member to selectively move the first electrically conductive member from the first axial position to the second axial position, step  930  of providing a second electrically conductive member spaced from the first electrically conductive member when the first electrically conductive member is in the first axial position, and step  932  of electrically engaging with the first electrically conductive member to the second electrically conductive member when the first electrically conductive member is in the second axial position. 
     The method also includes step  934  of providing a portion of the first member having a center of mass moveable from a first radial distance from the axis of rotation of the rotor when the rotor rotates at a first rotational speed to a second radial distance from the axis of rotation of the rotor when the rotor rotates at a second rotational speed different than the first rotational speed, the second radial distance being different than the first radial distance. 
     The method also includes step  936  of utilizing one of the of magnetic attraction and the magnetic repulsion to cause one of the first member and the second member to be one of magnetically attracted toward each other or magnetically repelled away from each other to cause the second member to engage the first electrically conductive member with the second electrically conductive member when the rotor reaches one of the first rotational speed and the second rotational speed. The inner cavity is generally cylindrical and wherein the moisture guide is generally planar. 
     The methods, systems, and apparatus described herein facilitate efficient and economical assembly of an electric machine. Exemplary embodiments of methods, systems, and apparatus are described and/or illustrated herein in detail. The methods, systems, and apparatus are not limited to the specific embodiments described herein, but rather, components of each apparatus and system, as well as steps of each method, may be utilized independently and separately from other components and steps described herein. Each component, and each method step, can also be used in combination with other components and/or method steps. 
     When introducing elements/components/etc. of the methods and apparatus described and/or illustrated herein, the articles “a”, “an”, “the”, and “the” are intended to mean that there are one or more of the element(s)/component(s)/etc. The terms “comprising”, “including”, and “having” are intended to be inclusive and mean that there may be additional element(s)/component(s)/etc. other than the listed element(s)/component(s)/etc. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims. 
     Described herein are exemplary methods, systems and apparatus utilizing lower cost materials in a permanent magnet machine that reduces or eliminates the efficiency loss caused by the lower cost material. Furthermore, the exemplary methods system and apparatus achieve increased efficiency while reducing or eliminating an increase of the length of the machine. The methods, system and apparatus described herein may be used in any suitable application. However, they are particularly suited for HVAC and pump applications. 
     Exemplary embodiments of the fluid flow device and system are described above in detail. The electric machine and its components are not limited to the specific embodiments described herein, but rather, components of the systems may be utilized independently and separately from other components described herein. For example, the components may also be used in combination with other machine systems, methods, and apparatuses, and are not limited to practice with only the systems and apparatus as described herein. Rather, the exemplary embodiments can be implemented and utilized in connection with many other applications. 
     Although specific features of various embodiments of the disclosure may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the disclosure, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.