The present invention relates to electric motors, and more particularly to electric motors utilized with hydromassage bathtubs.
Various electric motors have been utilized to drive pumps associated with hydromassage bathtubs. Nevertheless, a new electric motor for use with hydromassage bathtubs that provides ease of manufacturing, installation, and maintenance would be welcomed by those in the art.
Electric motors utilized for hydromassage bathtub applications are commonly located under the bathtub in a confined space. These space limitations often complicate installation and maintenance of the motor. The invention provides an electric motor that is designed to ease installation and maintenance of the motor. The motor is also designed to ease manufacturing of the motor.
In one embodiment, the invention provides an electric motor including a single end frame, a stator, a shaft, a rotor, and a canopy. The stator includes a stator core, a first end fixed relative to the end frame, and a second end remote from the end frame. The shaft is supported by the end frame for rotation about a shaft axis. The rotor includes opposite sides spaced in the direction of the shaft axis and is connected to the shaft for rotation with the shaft relative to the stator. The shaft is only supported on one side of the rotor for rotation about the shaft axis. The canopy is configured to cover at least a portion of the rotor and the second end of the stator during normal operation of the electric motor. A portion of the stator core is exposed between the end frame and the canopy at all times during normal operation of the electric motor. The shaft is not supported by the canopy for rotation about the shaft axis.
In another embodiment, the invention provides an electric motor including a single end frame, a stator, a shaft, a rotor, a canopy, and electrical components for operation of the electric motor. The end frame includes a conduit box. The stator includes a first end fixed relative to the end frame and a second end remote from the end frame. The shaft is supported by the end frame for rotation about a shaft axis. The rotor has opposite sides spaced in the direction of the shaft axis and is connected to the shaft for rotation with the shaft relative to the stator. The shaft is supported on only one side of the rotor for rotation about the shaft axis. The canopy is configured to cover at least a portion of the rotor and the second end of the stator during normal operation of the electric motor. The electrical components are at least partially positioned in the conduit box and are removable from the conduit box without removing the canopy. The shaft is not supported by the canopy for rotation about the shaft axis.
In another embodiment, the invention provides an electric motor including a single end frame, a stator, a shaft, and a rotor. The stator is fixed relative to the end frame. The shaft is supported by the end frame for rotation about a shaft axis. The rotor is connected to the shaft for rotation with the shaft relative to the stator. The end frame includes a surface that is transverse to the shaft axis that the stator is fixed against to locate the stator-relative to the end frame.
In yet another embodiment, the invention provides an electric motor including a single end frame having a conduit box and a lead wire window in communication with the conduit box. The lead wire window is fully enclosed by the end frame. The electric motor also includes electrical components for operation of the electric motor, a stator, lead wires for energization of the stator, a shaft, and a rotor. The electrical components are at least partially positioned in the conduit box. The stator is fixed relative to the end frame. The lead wires extend from the stator through the lead wire window and into the conduit box for connection to at least one of the electrical components. The shaft is supported by the end frame for rotation about a shaft axis. The rotor has opposite sides spaced in the direction of the shaft axis and is connected to the shaft for rotation with the shaft relative to the stator. The shaft is supported on only one side of the rotor for rotation about the shaft axis.
Further objects of the present invention together with the organization and manner of operation thereof, will become apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings wherein like elements have like numerals throughout the drawings.
The present invention is further described with reference to the accompanying drawings, which show an embodiment of the present invention. However, it should be noted that the invention as disclosed in the accompanying drawings is illustrated by way of example only. The various elements and combinations of elements described below and illustrated in the drawings can be arranged and organized differently to result in embodiments which are still within the spirit and scope of the present invention. Also, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. The use of “hydromassage bathtub,” “whirlpools,” “jetted bathtubs,” and variations thereof herein is meant to encompass drainable fluid-holding apparatus that include pumps for pumping fluid (e.g., water, air) through fluid jets in the fluid-holding apparatus.
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The grounding apparatus 57 includes a grounding aperture 50a located adjacent the slot portion 50b. As illustrated in
In the illustrated embodiment, the conduit box 22 is integrally connected or formed with the remainder of the end frame 14. In some embodiments, integrally forming the conduit box 22 with the remainder of the end frame 14 allows the conduit box to be minimally sized. Such sizing reduces the overall size of the motor 10 and contributes to the ease of installation and maintenance of the motor 10. In other embodiments, the conduit box 22 may be removably or permanently fixed to the remainder of the end frame 14.
The stator receiving portion 26 is sized to receive a portion of a stator 66. The stator 66 includes a stator core having a generally cylindrical portion 60a that is centered on the shaft axis during normal operation of the motor 10 and a planar portion 60b that is transverse (e.g., perpendicular) to the shaft axis during normal operation of the motor 10. As illustrated in
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The bearing hub 34 is sized to support a rotating assembly of the motor 10. With reference to
The bearing hub 34 is supported by a concave portion 94 of the end frame 14. As illustrated in
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The canopy 18 is configured to house or cover a portion of the stator 66 and a portion of the rotating assembly during normal operation of the motor 10. The canopy 18 includes air vents 98 and a shaft access aperture 102. The air vents 98 cooperate with the fan 90 to allow cooling air to pass through the motor compartment. The shaft access aperture 102 provides access to the end portion 70a of the shaft 78. The shaft access aperture 102 is illustrated as a round hole sized to receive a screw driver. In other embodiments, the shaft access aperture 102 may be alternatively sized and/or include an alternative shape. The canopy 18 also includes a flat portion 106 which allows for unencumbered access to the conduit box 22 when the motor 10 is assembled, and a support base 108 that works in combination with the support bases 42 to support the motor 10 during normal operation. In the illustrated embodiment, the canopy 18 is formed of plastic using an injection molding process.
For assembly of the motor 10, the end frame 14 is supported on a horizontal surface. The air switch 46 is installed by inserting the connector portion of the air switch 46 through the main portion 50a of the aperture 55 and sliding the air switch 46 into the slot portion 50b of the aperture 55 so the threaded portion of the air switch 46 extends from the conduit box 22 through the slot portion 50b. The air switch 46 is then secured to the surface of the conduit box 22 adjacent the slot portion 50b with a hex nut 40a. The power cord 50 is installed by securing the grounding wire 50a to the grounding apparatus 57 and inserting the connector portion of the power cord 50 through the main portion 50a of the aperture 55 and sliding the power cord 50 into the slot portion 50b of the aperture 55 to a position adjacent the air switch 46 so a slot in the strain relief 50b of the power cord 50 is engaged by the surface of the conduit box 22 adjacent the slot portion 50b. The power cord 50 prevents movement of the air switch 46 in the slot portion 20b. The capacitor 54 is installed by inserting the connector portion of the capacitor through the main portion 50a of the aperture 55 and securing the capacitor 54 to the conduit box 22 using a single fastener 50a. The capacitor 54 prevents movement of the power cord 50 and the air switch 46 in the slot portion 50b.
The stator 66 is located relative to the end frame 14 by the stator locating member 30. Due to the precision machining of the stator locating member 30 as explained above, an excellent alignment between the end frame 14 and stator 66 is achieved without requiring additional manufacturing processes, thus simplifying the manufacturing of the motor 10. The cylindrical portion 60a of the stator core is radially supported by the cylindrical surface 30a of the stator locating member 30 and the planar portion 60b of the stator core is axially supported by the planar surface 30b of the stator locating member 30.
The rotating assembly is installed by first inserting the first bearing 80 into the bearing bore 30a so the first bearing 80 is axially supported by the planar surface 30c. A retaining ring 109 (
The canopy 18 is connected to the end frame 14 using fasteners 114. In the illustrated embodiment, the fasteners 114 include bolts that extend through corresponding bores 118 in the stator core and corresponding bores 70b in the end frame 14. As illustrated in
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After all mechanical assembly processes are completed, the motor 10 is reoriented and the electrical connections are made through the access aperture 58. The lead wires extend through the lead wire window 38 and are electrically connected to the electrical components. The connections between the electrical components and the lead wires may vary based on the configuration of the motor 10. In other embodiments, the electrical connections can be made when installing the electrical components in the conduit box 22, thereby eliminating the need for the access aperture 58. When the electrical connections are completed, a cover 126 is utilize to cover the access aperture 58. The cover 126 includes tabs 120a on a bottom portion of the cover 126 and a hook 120b on a top portion of the cover 126. The tabs 120a engage the surface of the end frame 14 adjacent the access aperture 58 and the hook 120b is snapped into the brace 62. The cover 126 is only removable by using a tool such as a screw driver to depress the hook 120b and disengage the hook 120b from the brace 62. However, as discussed further below, the cover 126 generally does not need to be removed as maintenance of the electrical components can be accomplished by accessing the electrical components through the aperture 55.
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For field service of the motor 10, the field service technician only needs to remove the electrical components through the main portion 50a of the aperture 55 to perform standard maintenance. The field service technician does not need to remove any portion of the housing as is commonly required to perform maintenance on prior art motors. Removing a portion of the housing increases the likelihood that the factory provided motor alignment may be compromised. If the motor alignment is compromised, the operation of the motor is effected. Accordingly, the design of the motor 10 not only reduces the time required to perform maintenance, but also reduces the probability of compromising the operation of the motor 10.
The motor 210 includes an end frame 214 that includes a bearing hub 234. The bearing hub 234 is sized to support a rotating assembly of the motor 210. With reference to
A cover 226 is utilize to cover the access aperture 58. The cover 226 includes a tab 220a on a bottom portion of the cover 226 and a hook 220b on a top portion of the cover 226. The tab 220a engages the surface of the end frame 214 adjacent the access aperture 58 and the hook 220b is snapped into the brace 62.
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The canopy 218 also includes a canopy locating member 230 sized similar to the stator locating member 30. The canopy locating member 230 includes a cylindrical surface 230a centered on the shaft axis during normal operation of the motor 210 and a planar surface 230b that is transverse (e.g., perpendicular) to the shaft axis during normal operation of the motor 210. The canopy locating member 230 locates the canopy 218 with respect to the stator core. The precision utilized in the formation of the stator locating member 30 is not required for the canopy locating member 230 as the canopy 218 does not have a direct affect on the interaction between the stator 66 and the rotor 286. In the illustrated embodiment, the canopy 218 is formed of plastic using an injection molding process.
The stator 66 is fixed relative to the end frame 214 using fasteners 310. In the illustrated embodiment, the fasteners 310 are self-forming screws. The fasteners 310 are received in corresponding bores in the end frame 214. The fasteners 310 maintain the alignment between the stator 66 and the end frame 214 when removing nuts from fasteners 114 for connection to of the motor 210 to a load.
The embodiments described above and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present invention as set forth in the appended claims.