Patent Publication Number: US-8974198-B2

Title: Compressor having counterweight cover

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/232,626 filed on Aug. 10, 2009. The entire disclosure of the above application is incorporated herein by reference. 
    
    
     FIELD 
     The present disclosure relates to a compressor and more particularly to a compressor having a counterweight cover. 
     BACKGROUND 
     This section provides background information related to the present disclosure which is not necessarily prior art. 
     Cooling systems, refrigeration systems, heat-pump systems, and other climate-control systems typically include a condenser, an evaporator, an expansion device disposed between the condenser and evaporator, and a compressor circulating fluid between the condenser and the evaporator. The compressor may be one of any number of different compressors. For example, the compressor may be a reciprocating compressor or a scroll compressor that selectively circulates fluid among the various components of a cooling, refrigeration, or heat-pump system. Regardless of the particular type of compressor employed, consistent and reliable operation of the compressor is required to ensure that the cooling, refrigeration, or heat-pump system in which the compressor is installed is capable of consistently and reliably providing a cooling and/or heating effect on demand. 
     Compressors of the type described above often include a compression mechanism that compresses the fluid, thereby circulating the fluid within the refrigeration, cooling, or heat-pump system. Depending on the particular type of compressor, a drive shaft may be used to impart a force on and drive the compression mechanism. In order to reduce vibration of the compressor, such a drive shaft may include one or more counterweights that are sized and positioned relative to the drive shaft to rotationally balance the drive shaft. While the counterweight improves operation of the drive shaft and, thus, the compression mechanism, rotation of the counterweight may cause undesirable windage and/or oil circulation due to rotation within a shell of the compressor. Excessive oil circulation reduces the overall efficiency of the cooling, refrigeration, or heat-pump system, as oil within each system prevents optimal heat transfer within the condenser unit and evaporator unit of each system. 
     SUMMARY 
     This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
     A counterweight cover for a compressor is provided and may include an annular body having a recess at least partially defined by an outer circumferential portion, an inner circumferential portion, and an upper portion connecting the outer circumferential portion and the inner circumferential portion. A suction baffle may be disposed on the annular body and may direct a flow of suction gas within the compressor. 
     A compressor is provided and may include a motor assembly at least partially supported by a main-bearing housing, a counterweight associated with the motor assembly, and a counterweight cover fixed to the main-bearing housing and at least partially covering the counterweight. At least one anti-rotation feature may prevent relative rotation between the counterweight cover and the main-bearing housing. 
     A compressor is provided and may include a motor assembly at least partially supported by a main-bearing housing, a counterweight associated with the motor assembly, and a counterweight cover fixed to the main-bearing housing and at least partially covering the counterweight. A suction baffle may be integrally formed with the counterweight cover and a wire guide may be integrally formed with the counterweight cover. 
     Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
         FIG. 1  is a perspective view of a compressor according to the principles of the present disclosure; 
         FIG. 2  is a is a cross-sectional view of the compressor of  FIG. 1 ; 
         FIG. 3  is a perspective view of a main-bearing housing, a counterweight cover, a drive shaft, and a counterweight according to the principles of the present disclosure; 
         FIG. 4  is a perspective view of the main-bearing housing and counterweight cover of  FIG. 3 ; 
         FIG. 5  is an exploded view of the components of  FIG. 3 ; 
         FIG. 6  is an exploded view of the components of  FIG. 3 ; 
         FIG. 7  is a partial perspective view of a compressor including a suction baffle and wire guide; 
         FIG. 8  is a partial perspective view of the compressor of  FIG. 7  including a main-bearing housing; and 
         FIG. 9  is a perspective view of a wire guard according to the principles of the present disclosure. 
     
    
    
     Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. 
     Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth, such as examples of specific components and devices, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. 
     The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     When an element or layer is referred to as being “on,” “engaged to,” “connected to” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments. 
     Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     With reference to  FIGS. 1 and 2 , a compressor  10  is provided and may include a hermetic-shell assembly  12 , a main-bearing housing assembly  14 , a motor assembly  16 , a compression mechanism  18 , a refrigerant discharge fitting  22 , and a suction gas inlet fitting  26 . The compressor  10  may circulate fluid throughout a fluid circuit (not shown) of a refrigeration system, heat pump, or other climate-control system, for example. While the compressor  10  shown in the figures is a hermetic scroll refrigerant-compressor, the present teachings may be suitable for incorporation in many different types of scroll, rotary, and reciprocating compressors, for example, including hermetic machines, open-drive machines and non-hermetic machines. 
     The shell assembly  12  may house the main-bearing housing assembly  14 , the motor assembly  16 , and the compression mechanism  18 . The shell assembly  12  may generally form a compressor housing and may include a cylindrical shell  28 , an end cap  30  at the upper end thereof, a transversely extending partition  32 , and a base  34  at a lower end thereof. An oil sump  35  may be disposed at a lower end of the shell  28  and may provide lubricating oil to moving components of the compressor  10  such as, for example, compression mechanism  18 . The end cap  30  and partition  32  may cooperate to form a discharge chamber  36  that functions as a discharge muffler for the compressor  10 . 
     The refrigerant discharge fitting  22  may be attached to the shell assembly  12  at an opening  38  in the end cap  30 . A discharge valve assembly (not shown) may be located within the discharge fitting  22  and may prevent a reverse-flow condition to prevent fluid from entering the compressor  10  via the discharge fitting  22 . The suction gas inlet fitting  26  may be attached to the shell assembly  12  at an opening  40  of the shell  28  and is in fluid communication with an interior of the shell assembly  12 . The partition  32  may include a discharge passage  46  therethrough providing communication between the compression mechanism  18  and the discharge chamber  36 . The discharge-valve assembly could alternatively be located at or near the discharge passage  46 . 
     Referring now to  FIGS. 2-6 , the main-bearing housing assembly  14  may be affixed to the shell  28  at a plurality of locations in any suitable manner such as, for example, staking and/or welding. The main-bearing housing assembly  14  may include a main-bearing housing  52 , a first bearing  54  disposed therein, bushings  55 , and fasteners  57 . The main-bearing housing  52  may include a central-body portion  56  having a series of arms  58  extending radially outwardly therefrom, a first hub portion  60 , and a second hub portion  62  having an opening  64  extending through the first hub portion  60  and the second hub portion  62 . The central-body portion  56  may also include an annular flat thrust bearing surface  66  disposed on an axial end surface thereof. The second hub portion  62  may house the first bearing  54  therein for interaction with a drive shaft  80  of the motor assembly  16 . One or more of the arms  58  may include an aperture  70  extending therethrough and receiving the fasteners  57  to attach the compression mechanism  18  to the main-bearing housing  52 . Additionally, one of the arms  58  may include a wire guard mounting aperture  71  ( FIGS. 3 and 5 ) extending at least partially therethrough. 
     Referring now to  FIGS. 2 and 3 , the motor assembly  16  may generally include a motor stator  76 , a rotor  78 , the drive shaft  80 , and windings  82  that pass through the stator  76 . The motor stator  76  may be press fit into the shell  28  to fix the stator  76  relative to the shell  28 . The drive shaft  80  may be rotatably driven by the rotor  78 , which may be press fit on the drive shaft  80 . The drive shaft  80  may be rotatably supported by the first bearing  54  and may include an eccentric crank pin  84  having a crank pin flat  86  disposed thereon. 
     The compression mechanism  18  may generally include an orbiting scroll  104  and a non-orbiting scroll  106 . The orbiting scroll  104  may include an end plate  108  having a spiral vane or wrap  110  extending therefrom and an annular flat thrust surface  112 . The thrust surface  112  may interface with the thrust bearing surface  66  of the main-bearing housing  52 . The orbiting scroll  104  may also include a cylindrical hub  114  that projects downwardly from the thrust surface  112  and engages a drive bushing  116 . The drive bushing  116  may include an inner bore in which the crank pin  84  is drivingly disposed. In one configuration, the crank pin flat  86  drivingly engages a flat surface in a portion of the inner bore of the drive bushing  116  to provide a radially compliant driving arrangement. 
     The non-orbiting scroll  106  may include an end plate  118  having a spiral wrap  120  extending therefrom and a discharge passage  119  extending through the end plate  118 . The spiral wrap  120  may cooperate with the wrap  110  of the orbiting scroll  104  to create a series of moving fluid pockets when the orbiting scroll  104  is moved relative to the non-orbiting scroll  106 . The pockets created by the spiral wraps  110 ,  120  decrease in volume as they move from a radially outer position to a radially inner position, thereby compressing the fluid throughout a compression cycle of the compression mechanism  18 . 
     An Oldham coupling  117  may be positioned between orbiting scroll  104  and the main-bearing housing  52  and may be keyed to orbiting scroll  104  and non-orbiting scroll  106 . The Oldham coupling  117  transmits rotational forces from the drive shaft  80  to the orbiting scroll  104  to compress a fluid disposed between the orbiting scroll  104  and non-orbiting scroll  106 . Oldham coupling  117  and its interaction with orbiting scroll  104  and non-orbiting scroll  106  may be of the type disclosed in assignee&#39;s commonly-owned U.S. Pat. No. 5,320,506, the disclosure of which is incorporated herein by reference. 
     A lower counterweight  130  and/or an upper counterweight  132  may be associated with the motor assembly  16 . In one configuration, the counterweight  132  may be fixed to the rotor  78  to facilitate balanced rotation of the drive shaft  80 . In another configuration, the lower counterweight  130  and/or the upper counterweight  132  may be fixed to the drive shaft  80  instead of the rotor  78  to facilitate balanced rotation of the drive shaft  80 . A lower counterweight shield or cover  134  may at least partially cover the lower counterweight  130  and an upper counterweight shield or cover  136  may at least partially cover the upper counterweight  132 . The lower counterweight cover  134  may be mounted to the drive shaft  80  between the lower counterweight  130  and the oil sump  35  and may restrict oil from the oil sump  35  from splashing, splattering or otherwise flowing onto the lower counterweight  130 . Preventing oil from flowing onto the lower counterweight  130  reduces viscous drag on the lower counterweight  130  and the motor assembly  16  and reduces oil circulation by shielding the oil from the windage of the lower counterweight  130 . The lower counterweight cover  134  may be of the type disclosed in Assignee&#39;s commonly owned U.S. Pat. No. 5,064,356, the disclosure of which is hereby incorporated by reference. 
     Referring now to  FIGS. 3-9 , the upper counterweight cover  136  may be mounted to the main-bearing housing  52 . The upper counterweight cover  136  may include a generally annular body  138 , one or more anti-rotation features  140 , a suction baffle  142 , and a wire guide  144 , all of which may be integrally formed as a single, unitary body. The unitary construction of the upper counterweight cover  136  reduces the number of components of the compressor  10 , thereby reducing the complexity and cost associated with design and manufacturing of the compressor  10 . The upper counterweight cover  136  may be formed from a polymeric, metallic, or ceramic material, for example, or any other suitable material or combination of materials. The upper counterweight cover  136  may be formed from an injection-molding process, for example, and/or any other molding, forming, or machining process or combination of processes. 
     The annular body  138  may include a recess  146  defined by an outer circumferential portion  148 , an inner radial portion  150  and a generally flat upper portion  149 . The upper portion  149  may extend between the outer circumferential portion  148  and the inner radial portion  150  and generally perpendicular thereto. The upper portion  149  may include an upper surface  153  and a lower surface  152 . The inner radial portion  150  may include a plurality of resiliently flexible fingers  154  extending away from the upper portion  149 . Each of the flexible fingers  154  may include an inwardly extending lip  156  that engages a groove  158  formed in the second hub portion  62  of the main-bearing housing  52  via a snap fit, for example. 
     As described above, the second hub portion  62  may house the first bearing  54 , which rotatably supports the drive shaft  80 . The upper counterweight  132  may be fixed to the drive shaft  80  and may rotate therewith at least partially within the recess  146  of the upper counterweight cover  136 . In this manner, the outer circumferential portion  148  at least partially shrouds the upper counterweight  132  to reduce or prevent the upper counterweight  132  from spreading oil radially outward during rotation of the drive shaft  80 . Further, the upper counterweight cover  136  shields the motor assembly  16  from fluids disposed within the compressor  10 , such as oil and refrigerant, for example. 
     The anti-rotation features  140  may extend from the outer circumferential portion  148  and/or the upper surface  153  to the plurality of arms  58  of the main-bearing housing  52 . In the particular embodiment illustrated, the upper counterweight cover  136  includes four anti-rotation features  140 , each one corresponding to one of the four radially extending arms  58  of the main-bearing housing  52 . Each of the anti-rotation features  140  may include a cutout  160  having a generally rectangular shape that is sized and shaped to receive a portion of the corresponding arm  58  (as shown in  FIG. 4 ), thereby preventing relative rotation between the upper counterweight cover  136  and the main-bearing housing  52 . A width W1 of a first one or more of the cutouts  160  may differ from a width W2 of a second one or more of the cutouts  160  ( FIG. 4 ). Additionally or alternatively, the angular spacing between a particular cutout  160  and a first adjacent cutout  160  may be a first angle, while the angular spacing between the particular cutout  160  and a second adjacent cutout  160  may be a second angle that may be larger or smaller than the first angle. The differing widths W1, W2 and/or angular spacing between the cutouts  160  may correspond to differing widths and/or angular spacing of a particular one or more of the arms  58  of the main-bearing housing  52 . In this manner, differing widths W1, W2 and/or angular spacing between the plurality of cutouts  160  prevents the upper counterweight cover  136  from being assembled onto the main-bearing housing  52  in an incorrect orientation and ensures that the suction baffle  142  and wire guide  144  are positioned in the proper orientation with respect to the suction inlet fitting  26 , for example. 
     While the cutouts  160  are described above as being rectangular, the cutouts  160  could alternatively be formed in any other shape, such as triangular, trapezoidal, or arcuate, for example. In other embodiments, the anti-rotation features  140  may include pegs, pins or other features that engage the arms  58  of the main-bearing housing  52  and prevent relative rotation between the upper counterweight cover  136  and the main-bearing housing  52 . While the anti-rotation features  140  are described above as being integrally formed with the upper counterweight cover  136 , the anti-rotation features  140  could alternatively be separate members mounted to the annular body  138 , the suction baffle  142 , and/or the wire guide  144 . 
     The suction baffle  142  may include a first face  162 , a second face  164 , and a third face  166 . The first, second and third faces  162 ,  164 ,  166  may be generally flat or curved members with the third face  166  connecting the first and second faces  162 ,  164 . The first and second faces  162 ,  164  may be obtusely angled relative to the third face  166  while the third face  166  may be generally tangent to the outer circumferential portion  148  of the annular body  138 . The third face  166  may be positioned at an angle relative to the opening  40  of the suction gas inlet fitting  26 , such that the suction baffle  142 , as a whole, may be positioned at an angle relative to the suction gas inlet fitting  26  ( FIG. 7 ). A lip  168  may extend radially outwardly from the annular body  138  to protect the motor assembly  16  from debris and otherwise direct incoming refrigerant within the shell assembly  12 . While the suction baffle  142  is described above as being integrally formed with the upper counterweight cover  136 , the suction baffle  142  could alternatively be a separate component mounted to the annular body  138  or the main-bearing housing  52 , for example. Further, while the annular body  138  is described and shown as including a lip  168 , the lip  168  may be obviated if the suction baffle  142  sufficiently protects the motor assembly  16  from debris. 
     The suction baffle  142  directs the flow of suction gas entering the shell  28  through the suction gas inlet fitting  26  towards a suction window  169  ( FIG. 7 ) of the spiral wraps  110 ,  120  for compression. The suction gas deflects off of the first, second and/or third faces  162 ,  164 ,  166  and away from the upper counterweight  132 . In so doing, the suction baffle  142  reduces or eliminates interaction between the upper counterweight  132  and the suction gas and therefore reduces the drag experienced by the counterweight during rotation. Additionally, the suction baffle  142  may direct the suction gas away from the motor assembly, thereby reducing heat transfer between the motor assembly  16  and the suction gas. 
     Oil mixed in with the suction gas may contact the suction baffle  142  and subsequently drip down into the oil sump  35 . In another configuration, the lip  168  may extend outwardly and downwardly (relative to the view shown in  FIG. 3 ) and may be oriented relative to the suction gas inlet fitting  26  to allow the lip  168  to deflect a portion of the suction gas downward to cool the motor assembly  16 . 
     The wire guide  144  may be integrally formed with the second face  164  of the suction baffle  142  and may include a generally tubular portion  170  and a tab  172  extending therefrom. The tubular portion  170  may include a first portion  171  and a second portion  173  having a smaller diameter than the first portion  171 . A distal end of the second face  164  may curl inward to form the tubular portion  170  of the wire guide  144  such that the tubular portion  170  is integrally formed with the second face  164 . 
     The tubular portion  170  includes a first end  176  extending from the distal end of the second face  164  and a second end  178  that may be spaced less than 360 degrees apart from the first end  176  ( FIGS. 3 and 4 ). That is, the tubular portion  170  may be a discontinuous or open-sided tube such that the second end  178  is spaced apart from the suction baffle  142 , thereby forming an opening  181  ( FIG. 4 ). The tab  172  may extend from the second end  178  of the tubular portion  170 . 
     While the wire guide  144  is described above as being integrally formed with the second face  164 , the wire guide  144  could alternatively be integrally formed with the first face or third face  162 ,  166 . In other embodiments, the wire guide  144  may be a separate component mounted to the annular body  138 , one of the anti-rotation features  140 , the suction baffle  142 , the stator  76 , the shell  28  or any other suitable location. 
     Thermistor wires  180 ,  182  may extend between an electrical connection terminal  184  and scroll thermistor lead wires  186 ,  189  ( FIG. 7 ). The thermistor wires  180 ,  182  may be connected to a first connector  185 , and the scroll thermistor lead wires  186 ,  189  may be connected to a second connector  187 . The thermistor wires  180 ,  182  may be routed along stator  76  and up through the tubular portion  170 . The tubular portion  170  may locate and protect the thermistor wires  180 ,  182  within the shell  28  to allow the thermistor wires  180 ,  182  to be connected to the scroll thermistor lead wires  186 ,  189  via mating connectors  185 ,  187  received in a thermistor wire guard  188 . 
     The tab  172  may be gripped by an assembly or repair technician and pulled away from the suction baffle  142  to spread the tubular portion  170  open, thereby allowing easy insertion and removal of the thermistor wires  180 ,  182  into and out of the tubular portion  170 . While the wire guide  144  is described as positioning thermistor wires  180 ,  182 , the wire guide  144  may also be used to route other wires within the shell  28  instead of or in addition to the thermistor wires  180 ,  182  such as, for example, lines supplying power to the motor assembly  16 , a valve (not shown), or any other electrical device within the compressor  10 . 
     Referring now to  FIGS. 7-9 , the thermistor wire guard  188  may include a body portion  190 , a collar  192 , and a mounting stud  194 . The thermistor wire guard  188  may be injection molded or otherwise formed from a polymeric material, for example, and may facilitate assembly of the thermistor wires  180 ,  182  to the scroll thermistor lead wires  186 ,  189 . The thermistor wire guard  188  may cooperate with the wire guide  144  to protect and route the thermistor wires  180 ,  182 . In one configuration, the thermistor wire guard  188  and the wire guide  144  may be integrally formed as a single unitary component. 
     The body portion  190  may include a back wall  196 , side walls  198 , one or more retaining members  200 , a panel mount opening  202 , and a rib  204  protruding from the back wall  196 . The panel mount opening  202  may be defined by the back wall  196 , the side walls  198 , and the one or more retaining members  200 . The thermistor wires  180 ,  182  may be routed from the tubular portion  170  of the wire guide  144  up through the body portion  190  of the thermistor wire guard  188 . The panel mount opening  202  may receive and securely retain the first connector  185  via a snap-fit engagement, for example. The collar  192  may locate and guide the second connector  187  into engagement with the first connector  185 , and prevent improper engagement therebetween. 
     The rib  204  may engage an inner surface the shell  28  ( FIGS. 1 and 2 ) and maintain a spaced apart relationship between the shell  28  and the thermistor wires  180 ,  182 . In this manner, the rib  204  and back wall  196  may cooperate to protect the thermistor wires  180 ,  182  from damage that could occur due to contact with moving parts such as the orbiting scroll  104  or the Oldham coupling  117 , damage due to contact with the shell  28  during operation of the compressor  10 , or damage due to contact with the shell while the end cap  30  ( FIG. 1 ) is being welded onto the shell  28 . 
     The mounting stud  194  may be integrally formed with the body portion  190  and may include a stud portion  206  and a head portion  208 . The stud portion  206  may be slip-fit or otherwise received into the wire guard mounting aperture  71  in the main-bearing housing  52  to fix and position the thermistor wire guard  188  relative to the main-bearing housing  52 . The head portion  208  may facilitate installation of the mounting stud  194  onto the main-bearing housing  52  and may provide a stop to engage the non-orbiting scroll  106 , thereby preventing disengagement between the mounting stud  194  and the main-bearing housing  52 . 
     The scroll thermistor lead wires  186 ,  189  may extend between the second connector  187  and a scroll thermistor  210 , which may be connected to the non-orbiting scroll  106 . The scroll thermistor  210  may communicate with the discharge passage  119  ( FIG. 2 ) and may monitor a temperature of a discharge fluid flowing therethrough. Alternatively, the scroll thermistor  210  may communicate with a fluid pocket defined by the spiral wraps  110 ,  120  of the orbiting and non-orbiting scrolls  104 ,  106 , respectively, and may monitor a temperature of the fluid disposed therein. 
     A lanyard  212  may be employed to prevent any slack in the scroll thermistor lead wires  186 ,  189  from contacting the shell  28 , thereby preventing insulation on the scroll thermistor lead wires  186 ,  189  from being damaged while the end cap  30  is welded onto the shell  28 . The lanyard  212  may be formed from nylon or other polymeric material and may include a body portion  214 , a clip  216 , and a flag  218 . The body portion  214  may include a mounting aperture  215  engaging the scroll thermistor  210  generally between a head  220  of the thermistor  210  and the non-orbiting scroll  106 . In the configuration shown in  FIG. 8 , the head  220  of the thermistor  210  is shown as including a generally hex shape and the body portion  214  is shown as being captured under the hex head and retained thereon via a snap fit. 
     The clip  216  may be a generally C-shaped member extending from the body portion  214 . The clip  216  may include a slot  222  in communication with a clip aperture  224 . The scroll thermistor lead wires  186 ,  189  may be received through the slot  222  and into the clip aperture  224 , thereby retaining the scroll thermistor lead wires  186 ,  189  in place and preventing contact between the scroll thermistor lead wires  186 ,  189  and the shell  28 . 
     The flag  218  may extend from the body portion  214  and may be disposed approximately 180 degrees apart from the clip  216 . The flag  218  may be in an engaged position (shown in  FIGS. 7 and 8 ) when the clip  216  is engaging the scroll thermistor lead wires  186 ,  189 . The engaged position may be a generally horizontal position, as shown in  FIGS. 7 and 8 , or alternatively, may be positioned at an angle relative to the clip  216 . When the clip  216  is not engaged with the scroll thermistor lead wires  186 ,  189 , the lanyard  212  may be allowed to rotate about the center of the mounting aperture  215  out of the engaged position and into a disengaged position (not shown) due to an imbalance of weight between the clip  216  and the flag  218 . A sensing system (not shown) may be used during assembly of the compressor  10  to determine whether the flag is in the engaged position, thereby determining whether the clip  216  is engaged with the scroll thermistor lead wires  186 ,  189 . 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention.