CLUTCH ASSEMBLY CLUSTER FOR AN ENGINE PROTECTOR Field of the Invention This invention relates, in general, to a mounting apparatus for motor protectors and more particularly to a mounting clip for mounting a motor protector to the motor. stator of an electric motor. BACKGROUND OF THE INVENTION Dynamo-electric machines, such as an electric motor, typically include a protector, sometimes referred to herein as an overload protector, to de-energize the motor stator windings in the event of an overload or overcurrent condition. . In particular, in normal operation, the temperature of the stator windings is within a first temperature range. However, upon the occurrence of an overload condition, the temperature of the stator windings increases to a temperature above the first range. If the temperature of the windings becomes too high, the windings can be damaged. With respect to other fault conditions, such as a blocked rotor, high currents can flow through the stator windings. Under such high current conditions, the temperature of the windings can be significantly increased. Therefore, under high current conditions, the stator windings may be damaged. Known motor protectors include a switch having a movable contact and a stationary contact. A bimetallic element that responds to high temperatures and currents controls the movement of the moving contact. Commonly, the mobile contact is mounted on the bimetal element. A heating element is also usually connected in a series circuit with the contacts, for example, to the bimetallic element. The contacts, the bimetallic element and the heating element are arranged in a metal housing. The bimetallic element moves from a first position to a second position when heated above a transition temperature, sometimes referred to as a calibrated "disconnection" temperature. When the bimetallic element is sufficiently cooled, the bimetallic element returns to the first position from the second position. The stationary contact and the movable contact are in a circuit forming condition when the bimetallic element is in the first position. When the bimetallic element is in the second position, the stationary and mobile contacts are in a circuit break condition. Commonly the protector is placed adjacent to the final turns of the stator windings and is electrically connected in series circuit between a power source and the motor windings. For example, a first tip is connected at one end to the side of the stationary contact of the protective circuit and a second tip is connected at one end to the mobile contact side of the protective circuit. The other end of the first tip of the protector is connected to the power source and the other end of the second tip of the protector is connected to the common connection of the start and operation windings. Commonly, the protector is physically placed in a position relative to the stator windings so that the bimetallic element is heated to a temperature representative of the temperature of the stator windings. Under normal operating conditions, the bimetal element is in the first position and the stationary contact and the movable contact are in a circuit forming condition. Accordingly, the stator windings are energized. Upon the occurrence of an overload condition, for example, the stator windings, the heating element and the bimetallic element generate an increase in heat. If the temperature of the bimetallic element increases above the calibrated "disconnection" temperature, the bimetal element moves to the second position thus moving the contact out of engagement with the stationary contact to a circuit break condition. In an overcurrent condition, the flow of current through the bimetal element causes the bimetallic element itself to generate sufficient heat to cause the bimetallic element to disconnect, or move to the second position. Both in the overload condition and in the overcurrent condition, when the bimetallic element is disconnected, the supply current to the stator windings is interrupted and the windings are de-energized. In order to place an overload protector relative to an engine stator so that the guard responds to an overload condition, it is known to mount the guard to the stator in a variety of ways including using lashing ropes or straps, mounts that require bolts or screws, and clamps that require coupling with the motor housing. Although the lashing ropes or straps are useful with respect to placing the shield in a desired position, said lashing ropes or straps require manual application. In a high-volume manufacturing process, requiring workers to keep each thermal overload protector is a costly and time-consuming operation. Likewise, the application of assemblies that require bolts and screws is time consuming and complex. Such bolts and screws can also adversely affect the magnetic properties of the engine. With known clamps that attach the motor end shield to mount the guard in the desired position, by securing the motor end shield to the stator, it is possible to loosen the clamp from the desired position. In addition, some clamps are configured to fit with the stator windings within very limited tolerances. Any variation in the dimensions of the winding could prevent the proper mounting of such clamps. If the guard is not properly mounted, the guard may not operate to properly protect the stator windings. Accordingly, it is desirable and convenient to provide a protective motor mounting apparatus that is inexpensive to manufacture and that can be easily and quickly attached to the stator without the need to couple it with the motor end shields, and without the use of Mooring, bolts or screws. It is also desirable and convenient to provide a protective motor mounting apparatus which places the shield in close association with the stator windings and which is not adversely affected by slight variations in the dimensions of the windings. An object of the present invention is to provide a protective motor mounting apparatus that effectively secures the guard in close association with the stator windings of an electric motor so that the guard responds to the temperature of the stator winding. Another object of the present invention is to provide a protective motor mounting apparatus that does not affect the magnetic properties of the stator of an electric motor and does not require limited tolerances for mounting to the motor stator. Another additional objective of the present invention is to provide a motor protective mounting apparatus that is inexpensive to manufacture and that can easily and quickly be attached to an electric motor stator. Summary of the invention These and other objectives of the invention are achieved by an apparatus which, in one embodiment, is a mounting clip that includes a base having a front portion, a rear portion, an upper surface and a surface lower. A retainer member of the overload protector extends from the upper surface of the base. The lower surface of the base is configured to settle into a lamination, higher, or outermost of the rolling stack that forms the stator of the motor. The front portion of the base includes one or more limbs. Each end is configured to be inserted in a winding space formed by the stator windings. When inserted inside the winding space, each limb forms a friction fit with a portion of the stator windings and insulation. This friction adjustment keeps the mounting clip in position relative to the stator windings. Additional retention of the mounting clip is provided by a groove formed along the rear portion of the base. The slot is configured to cooperate with a stator rolling key and additionally facilitates the maintenance of the mounting clip in position without requiring coupling or contact between the motor end shield and the mounting clip and without the use of tie ropes, bolts, or screws. A rear portion of the mounting clip extends upwardly from the rear portion of the base and includes a substantially vertical section, a curved section, and a protruding section. One or more ribs extending between the back portion and the base are provided to reinforce the connection between the back portion and the base. The protruding section of the rear portion extends above the base and toward the front portion of the base. One or more L-shaped arms extend from the rear portion. A fastener region of the shield is formed by the base, the back portion, the L-shaped arms, and the retainer member. A locating tab extends from the curved section of the rear portion and is configured for a non-contacting relationship with the motor housing. To assemble the mounting clip and the overload protector, the overload protector is inserted into an insulating sleeve. Then, the sleeve and protector are placed within the clip holding region. The overload protector is initially maintained in the holding region by the cooperation of the base, the rear portion, the L-shaped arm portions, and the retaining member. The assembled mounting clip and overload protector are easily mounted to the stator by aligning each end of the clip with a space formed by the stator windings and then inserting each end into a respective aligned space. The tips of the clip are inserted into the respective spaces so that a portion of the shield contacts a portion of the stator windings. When assembled in this way, the ends of the mounting clip and the insulation and windings of the stator are in friction coupling.
With the assembly clip assembled and the guard secured to the stator, the motor end shields can then be secured to the motor stator. The tips of the guard and the stator windings extend through an opening in one of the motor end shields to an external control. If the motor end shield adjacent to the clip is properly secured and if the mounting clip is properly mounted, the positioning tab of the mounting clip does not contact the motor end shield. However, if the motor end shield is not properly aligned or if the mounting clip is not properly mounted, the positioning tab prevents complete securing of the motor end shield. In this way, the positioning tab serves as a check of the proper placement of the motor end shield and the mounting clip. The embodiment of the above-described mounting clip maintains a motor protector in thermal communication with at least a portion of the stator windings so that the guard responds to the temperature of the stator windings. The term "thermal communication" as used herein is not limited to meaning that the protector, or a portion of the protector, must be in direct or indirect physical contact with at least a portion of the stator windings. Rather, as used herein, this term means that the shield is configured and positioned in such a way that the heat generated by the stator windings affects the temperature of the bimetallic element. Of course, in addition to the heat generated by the stator windings, other elements such as heating elements can be used to generate heat and affect the state of the bimetallic element. The mounting clip described above is inexpensive to manufacture and facilitates the quick and easy mounting of a guard on a motor stator without requiring the use of tie ropes, bolts or screws. In addition, the mounting clip does not affect the magnetic characteristics of the motor and does not require limited tolerances in order to form a friction fit with the stator windings and insulation. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a motor protector mounting clip, in accordance with one embodiment of the present invention. Figure 2 is a top view of the mounting clip shown in Figure 1. Figure 3 is a side view of the mounting clip shown in Figure 1. Figure 4 is a rear view of the mounting clip shown in Figure 1. Figure 5 is a top view of an assembled guard and mounting clip secured to a motor stator. Figure 6 is a perspective view of the assembled protector and mounting clip secured to a motor stator, shown in Figure 5.
Detailed Description of the Drawings Figure 1 is a perspective view of a mounting clip 10, including a base 12, having an upper surface 14, a lower surface 16, a front portion 18 and a rear portion 20. front portion 18 includes a plurality of end segments 22A-C. A retainer member 24 extends from the base 12. A rear portion 26 extends from the rear portion 20 of the base 12. The rear portion 26 has a substantially vertical section 28, a curved section 30 and a projecting section 32. L-shaped arm portions 34A-B extend from the rear portion 26. Each L-shaped arm portion 34A-B has a first segment 36 and a second segment 38. The rib portions 40 formed between the base 12 and the rear portion 26, add force to support the rear portion 26. A fastener region of the shield 42 is formed by the base 12, the rear portion 26, L-shaped arm portions 34, and the retainer member 24. A tab Positioner 44, extends from the curved section 30 and, as described below, helps ensure proper positioning of the clip 10. A slot 46, formed in the rear portion 20 of the base 12, also helps to position the clip. ip
, as described below. Figure 2 is a top view of the mounting clip 10. As shown in Figure 2, the limb segments 22A-C extend in a substantially parallel relationship to each other and have substantially the same length. With respect to the L-shaped arm portions 34, the first segments 36 extend beyond the base 12 and the second segments 38 extend substantially perpendicular to the first segments 36 and to the front portion 18 of the base 12. The positioning tab 44 extends beyond the rear portion 20 of the base 12. Figure 3 is a side view of the mounting clip 10. The projecting section 32 extends over and beyond the retainer member 24 toward the front portion 18. of the base 12. The extension of the positioning tab 44 beyond the rear portion 20 of the base 12 is also illustrated. Figure 4 is a rear view of the mounting clip 10. With respect to the rear portion 26, in the area extending from the base 12 to the arm portions 34, the width of the rear portion 26 is substantially the same width as the base 12. The width of the curved section 30 and of the projecting section 32 is less than the width of the base 12. The specific relative dimensions of the clip 10, including the back portion 26, can be selected in order to accommodate the particular protector that is going to be used. The mounting clip 10 is made of Valox® plastic (Valox is a trademark of General Electric Company) using an injection molding process. Valox plastic is a plastic of polybutylene terephthalate. A rectangular opening 48 in the rear portion 26 is used in the injection molding process for the formation of the retaining tab 24. The injection molding process is a non-expensive way of manufacturing the mounting clip 10. Of course it is they can use other materials and processes to manufacture the mounting clip 10. Figure 5 is a top view of the mounting clip 10, secured to a stator of the motor 50. The stator 50 includes stator lamination teeth 52A defining slots of the stator. 52B winding. Stator windings 54 are wound around selected teeth 52A and through selected slots 52B. The windings 54, as illustrated schematically in Figure 5, include start and run windings. As is well known, in operation, the start winding can be used for motor start-up and as an auxiliary main winding. Of course, many other winding configurations are possible. The mounting clip 10 is not limited to its use with any particular winding configuration. As shown in Figure 5, a shield 56 is inserted into the fastening region 42 of the clip 10 and a portion of the shield 56 contacts a portion of the windings 54. The shield 56 includes a metal housing 58. Said housing 58 includes a plate portion 60 and a container portion 62. The plate portion 60 is electrically isolated from the container portion 62 but is attached to the container portion 62. A switch (not shown) having a stationary contact and a movable contact is shown within the housing 58. A bimetallic element and a heating element are also mounted within the housing 58. The bimetallic element, as described below, controls the movement of the movable contact. More specifically, the heating element and one end of the bimetallic element are welded to the plate portion 60, as for example by spot welding. The movable contact is mounted on the other end of the bimetal element and is aligned with the stationary contact. The stationary contact is attached to the container portion 62 of the housing 58. A first tip 64 is attached to an end a, and is in electrical circuit with, the container portion 62. A second tip 66 is attached to one end a, and is in electrical circuit with the plate portion 60. The other end of the second tip 66 is connected to the common connection of the stator windings 54. The bimetallic element is calibrated to "disconnect" or move, from a first position to a second position, when the temperature of the bimetallic element increases above the calibrated "disconnection" temperature. As described hereinafter, the first position of the bimetallic element corresponds to a circuit formation condition and the second position of the bimetallic element corresponds to a condition of circuit rupture. The bimetallic element is usually in the first position. Protectors, such as protector 56, which may be used in combination with clip 10, are commercially available such as Model # 8AM Series available from Texas Instruments Canada Limited, 280 Center Street East, Richmond Hill, Ontario, Canada L4C 1 B1 The specific interruption characteristics, including the calibrated "disconnection" temperature, of the bimetallic element can be selected depending on the particular application. To assemble the clip 10 and guard 56 to the stator 50, the metal housing is placed inside a Mylar sheath (not shown). Mylar is a Dupont brand for a polyethylene terephthalate film. As described above, the metal housing 58 is part of the electrical circuit of the protector 56. The Mylar sleeve isolates the housing 58 from the windings of the stator 54 and transmits heat from the windings of the stator 54 to the metallic housing 58. Of course, it is You can use materials other than Mylar plastic for the protector cover. After the housing 58 is inserted into the Mylar sheath, the housing 58 is positioned within the grip region 42 of the clip 10. The assembled mounting clip 10 and the shield 56 are then mounted to the stator 50, aligning the end segments of clip 22A-C with stator teeth selected 52A. The stator windings 54 form spaces in the location of the teeth 52A, and the end segments of the clip 22A-C are inserted in said spaces along the teeth 52A. The mounting clip 10 is urged towards the windings of the stator 54, until at least a portion of the Mylar sleeve of the protector 56 makes firm contact in at least a portion of the stator windings 54. As shown schematically in FIG. Figure 5, protector 56, is in contact with a portion of the motor winding. Figure 6 is a perspective view of the mounting clip 10 secured to the stator 50. Only a portion of the stator 50 is shown in Figure 6. The stator 50 includes a plurality of laminations 68 held together in a stack by a key of the stator 70. The insulation wedges 72 are located in the winding slots 52B and are disposed between the windings of the stator 54 and the laminations 58. The end segments of the clip 22A-C are dimensioned to form a friction fit with insulation wedges 72 and windings .54. Said friction adjustment keeps the mounting clip 10 in the desired position. Specifically, the limbs 22A-C make physical contact with the wedges 72, and the forces generated by the wedges 72, the windings 54 and the ends 22A-C act to keep the clip 10 in position. Also, the slot 46 located along the rear portion 20 of the clip 10 cooperates with the stator key 70 to further secure the mounting clip 10 in position. Specifically, the cooperation of the stator key 70 and the slot 46 limits the radial movement of the clip 10. Once the mounting clip 10 and guard 56 are suitably mounted to the stator 50, the entire stator assembly can be varnished. The application of the varnish further helps to keep the mounting clip 10 in the desired position. Of course it is contemplated that the varnish step could be eliminated. The motor end shields (not shown) are assembled to the stator 50 after the assembled clip 10 and guard 56 are secured to the stator 50, as described above. The clip 10, adjacent to the motor end shield cooperates with the positioning tab 44 of the clip 10, so that if the end shield is not properly aligned, or if the mounting clip 10 is not properly mounted, the positioning tab 44 prevents the motor end shield from being completely secured. When both the motor end shield and the clip 10 are mounted properly, the mounting clip 10 does not contact the motor end shield. Accordingly, the positioning tab 44 is a check of the proper positioning of the motor end shield and the mounting clip 10. The first tip 64, which is connected at one end to the shield 56, extends through an opening in the engine end shield. Prior to operation, the first tip 64 is connected, at the end extending through the motor end shield, to an energy source. The electrical circuit of the power source to the windings of the stator 54 is through the protector 56. Particularly, the current flows from the power source through the first tip 64 and the container portion 62 to the stationary contact of the protector 56. If the bimetallic element is in the first position, that is, in the circuit forming position, then the current flows from the stationary contact to the moving contact and through the bimetallic element and the heating element to the plate portion 60. As the second tip 66 is electrically connected to the plate portion 60, the current flows from the plate portion 60 through the second tip 66 to the windings of the stator 54. In this way, the stator windings 54 are energized. Under normal conditions, the bimetallic element of protector 56 is in the first position. Accordingly, the mobile and stationary contacts of shield 56 are in the circuit forming condition. The heat generated by the windings of the stator 54 is transferred through the shield sleeve and the shield housing 58 to the bimetallic element. The heat generated by the heating element and the bimetallic element itself also heats the bimetallic element. However, under normal conditions, the heat generated by the windings of the stator 54, the heating element and the bimetallic element is not sufficient to heat the bimetallic element above its calibrated "disconnection" temperature. Accordingly, under normal operating conditions, the movable and stationary contacts remain in the circuit forming condition. However, if the temperature of the stator windings 54 exceeds the normal operating temperature range, the bimetallic element is heated to or above the calibrated "disconnection" temperature, thus moving the mobile contact out of contact with the stationary contact, it is say, the position of rupture of the circuit. In addition, if the windings 54 produce a preselected excess current, the bimetallic element itself generates sufficient heat so that the temperature of the bimetallic element increases to or above the calibrated "disconnection" temperature. As explained above, when the bimetallic element is heated to or above the calibrated "disconnection" temperature, the bimetallic element moves to the second position, i.e., the rupture condition of the circuit, and the stator windings 54 are de-energized. For overload and overcurrent conditions, when the windings 54, the heating element and the bimetallic element are sufficiently cooled, the bimetallic element returns to the first position and the windings 54 are energized. If the condition that caused the bimetallic element to "disconnect" has been corrected, the normal operation of the motor resumes. Otherwise, the bimetal element will again begin to be heated to the calibrated "disconnection" temperature and the windings 54 will be de-energized. As explained above, the mounting clip 10 is not expensive to manufacture and is installed quickly and easily in a motor stator. Additionally, the mounting clip 10 provides an effective mounting apparatus for securing the protector 56 in thermal communication with a portion of the stator windings 54. Said mounting of the protector 56 facilitates ensuring a timely response to a high temperature condition of the components. windings of the stator 54, which, of course, is important to protect the windings 54 from an overload condition. In addition, the 1 0 clip does not require the use of ropes, bolts or screws and the 1 0 clip does not adversely affect the magnetic properties of the motor. Of course other types of thermal overload protectors other than a bimetal type shield can be used with the clip 10, such as a positive temperature coefficient resistor (PTCR). As is well known, the resistance of the positive temperature coefficient resistor increases in relation to the increase in temperature. At a predetermined temperature, the resistance of the positive temperature coefficient resistor becomes so large that the current flow through the positive temperature coefficient resi stor is restricted or substantially choked so that the positive temperature coefficient resistor is dissociated from the circuit, that is, an "open" circuit. Also, although thermal communication between the windings of the stator and the shield is generally desirable, such thermal communication is not always necessary in each application, and the mounting clip 10 may be used in the aforementioned other applications. The specific electrical connections between a shield and the motor depend, for example, on the types of shield and motor. Accordingly, the description of the electrical connections and the operation of the protector and the motor set forth above are only by way of example. From the above description, it is evident that the objects of the invention were achieved. Although the invention has been described and illustrated in detail, it should be clearly understood that the intention thereof is only by way of illustration and should not be taken as limiting. For example, variation in the number of limb segments 22A-C is contemplated. Additionally, the size and shape of the holding region 42 could be altered to accommodate the size and shape of a particular protector 56. Accordingly, the spirit and scope of the invention will be limited only by the terms of the appended claims.