Compressor having counterweight cover

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.

FIELD

The present disclosure relates to a compressor and more particularly to a compressor having a counterweight cover.

BACKGROUND

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

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.

DETAILED DESCRIPTION

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.

With reference toFIGS. 1 and 2, a compressor10is provided and may include a hermetic-shell assembly12, a main-bearing housing assembly14, a motor assembly16, a compression mechanism18, a refrigerant discharge fitting22, and a suction gas inlet fitting26. The compressor10may circulate fluid throughout a fluid circuit (not shown) of a refrigeration system, heat pump, or other climate-control system, for example. While the compressor10shown 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 assembly12may house the main-bearing housing assembly14, the motor assembly16, and the compression mechanism18. The shell assembly12may generally form a compressor housing and may include a cylindrical shell28, an end cap30at the upper end thereof, a transversely extending partition32, and a base34at a lower end thereof. An oil sump35may be disposed at a lower end of the shell28and may provide lubricating oil to moving components of the compressor10such as, for example, compression mechanism18. The end cap30and partition32may cooperate to form a discharge chamber36that functions as a discharge muffler for the compressor10.

The refrigerant discharge fitting22may be attached to the shell assembly12at an opening38in the end cap30. A discharge valve assembly (not shown) may be located within the discharge fitting22and may prevent a reverse-flow condition to prevent fluid from entering the compressor10via the discharge fitting22. The suction gas inlet fitting26may be attached to the shell assembly12at an opening40of the shell28and is in fluid communication with an interior of the shell assembly12. The partition32may include a discharge passage46therethrough providing communication between the compression mechanism18and the discharge chamber36. The discharge-valve assembly could alternatively be located at or near the discharge passage46.

Referring now toFIGS. 2-6, the main-bearing housing assembly14may be affixed to the shell28at a plurality of locations in any suitable manner such as, for example, staking and/or welding. The main-bearing housing assembly14may include a main-bearing housing52, a first bearing54disposed therein, bushings55, and fasteners57. The main-bearing housing52may include a central-body portion56having a series of arms58extending radially outwardly therefrom, a first hub portion60, and a second hub portion62having an opening64extending through the first hub portion60and the second hub portion62. The central-body portion56may also include an annular flat thrust bearing surface66disposed on an axial end surface thereof. The second hub portion62may house the first bearing54therein for interaction with a drive shaft80of the motor assembly16. One or more of the arms58may include an aperture70extending therethrough and receiving the fasteners57to attach the compression mechanism18to the main-bearing housing52. Additionally, one of the arms58may include a wire guard mounting aperture71(FIGS. 3 and 5) extending at least partially therethrough.

Referring now toFIGS. 2 and 3, the motor assembly16may generally include a motor stator76, a rotor78, the drive shaft80, and windings82that pass through the stator76. The motor stator76may be press fit into the shell28to fix the stator76relative to the shell28. The drive shaft80may be rotatably driven by the rotor78, which may be press fit on the drive shaft80. The drive shaft80may be rotatably supported by the first bearing54and may include an eccentric crank pin84having a crank pin flat86disposed thereon.

The compression mechanism18may generally include an orbiting scroll104and a non-orbiting scroll106. The orbiting scroll104may include an end plate108having a spiral vane or wrap110extending therefrom and an annular flat thrust surface112. The thrust surface112may interface with the thrust bearing surface66of the main-bearing housing52. The orbiting scroll104may also include a cylindrical hub114that projects downwardly from the thrust surface112and engages a drive bushing116. The drive bushing116may include an inner bore in which the crank pin84is drivingly disposed. In one configuration, the crank pin flat86drivingly engages a flat surface in a portion of the inner bore of the drive bushing116to provide a radially compliant driving arrangement.

The non-orbiting scroll106may include an end plate118having a spiral wrap120extending therefrom and a discharge passage119extending through the end plate118. The spiral wrap120may cooperate with the wrap110of the orbiting scroll104to create a series of moving fluid pockets when the orbiting scroll104is moved relative to the non-orbiting scroll106. The pockets created by the spiral wraps110,120decrease 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 mechanism18.

An Oldham coupling117may be positioned between orbiting scroll104and the main-bearing housing52and may be keyed to orbiting scroll104and non-orbiting scroll106. The Oldham coupling117transmits rotational forces from the drive shaft80to the orbiting scroll104to compress a fluid disposed between the orbiting scroll104and non-orbiting scroll106. Oldham coupling117and its interaction with orbiting scroll104and non-orbiting scroll106may be of the type disclosed in assignee's commonly-owned U.S. Pat. No. 5,320,506, the disclosure of which is incorporated herein by reference.

A lower counterweight130and/or an upper counterweight132may be associated with the motor assembly16. In one configuration, the counterweight132may be fixed to the rotor78to facilitate balanced rotation of the drive shaft80. In another configuration, the lower counterweight130and/or the upper counterweight132may be fixed to the drive shaft80instead of the rotor78to facilitate balanced rotation of the drive shaft80. A lower counterweight shield or cover134may at least partially cover the lower counterweight130and an upper counterweight shield or cover136may at least partially cover the upper counterweight132. The lower counterweight cover134may be mounted to the drive shaft80between the lower counterweight130and the oil sump35and may restrict oil from the oil sump35from splashing, splattering or otherwise flowing onto the lower counterweight130. Preventing oil from flowing onto the lower counterweight130reduces viscous drag on the lower counterweight130and the motor assembly16and reduces oil circulation by shielding the oil from the windage of the lower counterweight130. The lower counterweight cover134may be of the type disclosed in Assignee's commonly owned U.S. Pat. No. 5,064,356, the disclosure of which is hereby incorporated by reference.

Referring now toFIGS. 3-9, the upper counterweight cover136may be mounted to the main-bearing housing52. The upper counterweight cover136may include a generally annular body138, one or more anti-rotation features140, a suction baffle142, and a wire guide144, all of which may be integrally formed as a single, unitary body. The unitary construction of the upper counterweight cover136reduces the number of components of the compressor10, thereby reducing the complexity and cost associated with design and manufacturing of the compressor10. The upper counterweight cover136may be formed from a polymeric, metallic, or ceramic material, for example, or any other suitable material or combination of materials. The upper counterweight cover136may be formed from an injection-molding process, for example, and/or any other molding, forming, or machining process or combination of processes.

The annular body138may include a recess146defined by an outer circumferential portion148, an inner radial portion150and a generally flat upper portion149. The upper portion149may extend between the outer circumferential portion148and the inner radial portion150and generally perpendicular thereto. The upper portion149may include an upper surface153and a lower surface152. The inner radial portion150may include a plurality of resiliently flexible fingers154extending away from the upper portion149. Each of the flexible fingers154may include an inwardly extending lip156that engages a groove158formed in the second hub portion62of the main-bearing housing52via a snap fit, for example.

As described above, the second hub portion62may house the first bearing54, which rotatably supports the drive shaft80. The upper counterweight132may be fixed to the drive shaft80and may rotate therewith at least partially within the recess146of the upper counterweight cover136. In this manner, the outer circumferential portion148at least partially shrouds the upper counterweight132to reduce or prevent the upper counterweight132from spreading oil radially outward during rotation of the drive shaft80. Further, the upper counterweight cover136shields the motor assembly16from fluids disposed within the compressor10, such as oil and refrigerant, for example.

The anti-rotation features140may extend from the outer circumferential portion148and/or the upper surface153to the plurality of arms58of the main-bearing housing52. In the particular embodiment illustrated, the upper counterweight cover136includes four anti-rotation features140, each one corresponding to one of the four radially extending arms58of the main-bearing housing52. Each of the anti-rotation features140may include a cutout160having a generally rectangular shape that is sized and shaped to receive a portion of the corresponding arm58(as shown inFIG. 4), thereby preventing relative rotation between the upper counterweight cover136and the main-bearing housing52. A width W1 of a first one or more of the cutouts160may differ from a width W2 of a second one or more of the cutouts160(FIG. 4). Additionally or alternatively, the angular spacing between a particular cutout160and a first adjacent cutout160may be a first angle, while the angular spacing between the particular cutout160and a second adjacent cutout160may 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 cutouts160may correspond to differing widths and/or angular spacing of a particular one or more of the arms58of the main-bearing housing52. In this manner, differing widths W1, W2 and/or angular spacing between the plurality of cutouts160prevents the upper counterweight cover136from being assembled onto the main-bearing housing52in an incorrect orientation and ensures that the suction baffle142and wire guide144are positioned in the proper orientation with respect to the suction inlet fitting26, for example.

While the cutouts160are described above as being rectangular, the cutouts160could alternatively be formed in any other shape, such as triangular, trapezoidal, or arcuate, for example. In other embodiments, the anti-rotation features140may include pegs, pins or other features that engage the arms58of the main-bearing housing52and prevent relative rotation between the upper counterweight cover136and the main-bearing housing52. While the anti-rotation features140are described above as being integrally formed with the upper counterweight cover136, the anti-rotation features140could alternatively be separate members mounted to the annular body138, the suction baffle142, and/or the wire guide144.

The suction baffle142may include a first face162, a second face164, and a third face166. The first, second and third faces162,164,166may be generally flat or curved members with the third face166connecting the first and second faces162,164. The first and second faces162,164may be obtusely angled relative to the third face166while the third face166may be generally tangent to the outer circumferential portion148of the annular body138. The third face166may be positioned at an angle relative to the opening40of the suction gas inlet fitting26, such that the suction baffle142, as a whole, may be positioned at an angle relative to the suction gas inlet fitting26(FIG. 7). A lip168may extend radially outwardly from the annular body138to protect the motor assembly16from debris and otherwise direct incoming refrigerant within the shell assembly12. While the suction baffle142is described above as being integrally formed with the upper counterweight cover136, the suction baffle142could alternatively be a separate component mounted to the annular body138or the main-bearing housing52, for example. Further, while the annular body138is described and shown as including a lip168, the lip168may be obviated if the suction baffle142sufficiently protects the motor assembly16from debris.

The suction baffle142directs the flow of suction gas entering the shell28through the suction gas inlet fitting26towards a suction window169(FIG. 7) of the spiral wraps110,120for compression. The suction gas deflects off of the first, second and/or third faces162,164,166and away from the upper counterweight132. In so doing, the suction baffle142reduces or eliminates interaction between the upper counterweight132and the suction gas and therefore reduces the drag experienced by the counterweight during rotation. Additionally, the suction baffle142may direct the suction gas away from the motor assembly, thereby reducing heat transfer between the motor assembly16and the suction gas.

Oil mixed in with the suction gas may contact the suction baffle142and subsequently drip down into the oil sump35. In another configuration, the lip168may extend outwardly and downwardly (relative to the view shown inFIG. 3) and may be oriented relative to the suction gas inlet fitting26to allow the lip168to deflect a portion of the suction gas downward to cool the motor assembly16.

The wire guide144may be integrally formed with the second face164of the suction baffle142and may include a generally tubular portion170and a tab172extending therefrom. The tubular portion170may include a first portion171and a second portion173having a smaller diameter than the first portion171. A distal end of the second face164may curl inward to form the tubular portion170of the wire guide144such that the tubular portion170is integrally formed with the second face164.

The tubular portion170includes a first end176extending from the distal end of the second face164and a second end178that may be spaced less than 360 degrees apart from the first end176(FIGS. 3 and 4). That is, the tubular portion170may be a discontinuous or open-sided tube such that the second end178is spaced apart from the suction baffle142, thereby forming an opening181(FIG. 4). The tab172may extend from the second end178of the tubular portion170.

While the wire guide144is described above as being integrally formed with the second face164, the wire guide144could alternatively be integrally formed with the first face or third face162,166. In other embodiments, the wire guide144may be a separate component mounted to the annular body138, one of the anti-rotation features140, the suction baffle142, the stator76, the shell28or any other suitable location.

Thermistor wires180,182may extend between an electrical connection terminal184and scroll thermistor lead wires186,189(FIG. 7). The thermistor wires180,182may be connected to a first connector185, and the scroll thermistor lead wires186,189may be connected to a second connector187. The thermistor wires180,182may be routed along stator76and up through the tubular portion170. The tubular portion170may locate and protect the thermistor wires180,182within the shell28to allow the thermistor wires180,182to be connected to the scroll thermistor lead wires186,189via mating connectors185,187received in a thermistor wire guard188.

The tab172may be gripped by an assembly or repair technician and pulled away from the suction baffle142to spread the tubular portion170open, thereby allowing easy insertion and removal of the thermistor wires180,182into and out of the tubular portion170. While the wire guide144is described as positioning thermistor wires180,182, the wire guide144may also be used to route other wires within the shell28instead of or in addition to the thermistor wires180,182such as, for example, lines supplying power to the motor assembly16, a valve (not shown), or any other electrical device within the compressor10.

Referring now toFIGS. 7-9, the thermistor wire guard188may include a body portion190, a collar192, and a mounting stud194. The thermistor wire guard188may be injection molded or otherwise formed from a polymeric material, for example, and may facilitate assembly of the thermistor wires180,182to the scroll thermistor lead wires186,189. The thermistor wire guard188may cooperate with the wire guide144to protect and route the thermistor wires180,182. In one configuration, the thermistor wire guard188and the wire guide144may be integrally formed as a single unitary component.

The body portion190may include a back wall196, side walls198, one or more retaining members200, a panel mount opening202, and a rib204protruding from the back wall196. The panel mount opening202may be defined by the back wall196, the side walls198, and the one or more retaining members200. The thermistor wires180,182may be routed from the tubular portion170of the wire guide144up through the body portion190of the thermistor wire guard188. The panel mount opening202may receive and securely retain the first connector185via a snap-fit engagement, for example. The collar192may locate and guide the second connector187into engagement with the first connector185, and prevent improper engagement therebetween.

The rib204may engage an inner surface the shell28(FIGS. 1 and 2) and maintain a spaced apart relationship between the shell28and the thermistor wires180,182. In this manner, the rib204and back wall196may cooperate to protect the thermistor wires180,182from damage that could occur due to contact with moving parts such as the orbiting scroll104or the Oldham coupling117, damage due to contact with the shell28during operation of the compressor10, or damage due to contact with the shell while the end cap30(FIG. 1) is being welded onto the shell28.

The mounting stud194may be integrally formed with the body portion190and may include a stud portion206and a head portion208. The stud portion206may be slip-fit or otherwise received into the wire guard mounting aperture71in the main-bearing housing52to fix and position the thermistor wire guard188relative to the main-bearing housing52. The head portion208may facilitate installation of the mounting stud194onto the main-bearing housing52and may provide a stop to engage the non-orbiting scroll106, thereby preventing disengagement between the mounting stud194and the main-bearing housing52.

The scroll thermistor lead wires186,189may extend between the second connector187and a scroll thermistor210, which may be connected to the non-orbiting scroll106. The scroll thermistor210may communicate with the discharge passage119(FIG. 2) and may monitor a temperature of a discharge fluid flowing therethrough. Alternatively, the scroll thermistor210may communicate with a fluid pocket defined by the spiral wraps110,120of the orbiting and non-orbiting scrolls104,106, respectively, and may monitor a temperature of the fluid disposed therein.

A lanyard212may be employed to prevent any slack in the scroll thermistor lead wires186,189from contacting the shell28, thereby preventing insulation on the scroll thermistor lead wires186,189from being damaged while the end cap30is welded onto the shell28. The lanyard212may be formed from nylon or other polymeric material and may include a body portion214, a clip216, and a flag218. The body portion214may include a mounting aperture215engaging the scroll thermistor210generally between a head220of the thermistor210and the non-orbiting scroll106. In the configuration shown inFIG. 8, the head220of the thermistor210is shown as including a generally hex shape and the body portion214is shown as being captured under the hex head and retained thereon via a snap fit.

The clip216may be a generally C-shaped member extending from the body portion214. The clip216may include a slot222in communication with a clip aperture224. The scroll thermistor lead wires186,189may be received through the slot222and into the clip aperture224, thereby retaining the scroll thermistor lead wires186,189in place and preventing contact between the scroll thermistor lead wires186,189and the shell28.

The flag218may extend from the body portion214and may be disposed approximately 180 degrees apart from the clip216. The flag218may be in an engaged position (shown inFIGS. 7 and 8) when the clip216is engaging the scroll thermistor lead wires186,189. The engaged position may be a generally horizontal position, as shown inFIGS. 7 and 8, or alternatively, may be positioned at an angle relative to the clip216. When the clip216is not engaged with the scroll thermistor lead wires186,189, the lanyard212may be allowed to rotate about the center of the mounting aperture215out of the engaged position and into a disengaged position (not shown) due to an imbalance of weight between the clip216and the flag218. A sensing system (not shown) may be used during assembly of the compressor10to determine whether the flag is in the engaged position, thereby determining whether the clip216is engaged with the scroll thermistor lead wires186,189.