The present invention generally relates to scroll compressors for compressing refrigerant and more particularly to scroll compressors including a floating seal arrangement interacting with a fixed scroll.
A scroll compressor is a certain type of compressor that is used to compress refrigerant for such applications as refrigeration, air conditioning, industrial cooling and freezer applications, and/or other applications where compressed fluid may be used. Such prior scroll compressors are known, for example, as exemplified in U.S. Pat. Nos. 6,398,530 to Hasemann; 6,814,551, to Kammhoff et al.; 6,960,070 to Kammhoff et al.; and 7,112,046 to Kammhoff et al., all of which are assigned to a Bitzer entity closely related to the present assignee. As the present disclosure pertains to improvements that can be implemented in these or other scroll compressor designs, the entire disclosures of U.S. Pat. Nos. 6,398,530; 7,112,046; 6,814,551; and 6,960,070 are hereby incorporated by reference in their entireties.
As is exemplified by these patents, scroll compressors assemblies conventionally include an outer housing having a scroll compressor contained therein. A scroll compressor includes first and second scroll compressor bodies. A first scroll compressor body is typically arranged stationary and fixed in the outer housing. A second scroll compressor body is movable relative to the first scroll compressor body in order to compress refrigerant between respective scroll ribs which rise above the respective bases and engage in one another. Conventionally the movable scroll compressor member is driven about an orbital path about a central axis for the purposes of compressing refrigerant. An appropriate drive unit, typically an electric motor, is provided usually within the same housing to drive the movable scroll member.
In some scroll compressors, it is known to have axial restraint, whereby the fixed scroll compressor body has a limited range of movement. This can be desirable due to thermal expansion when the temperature of the orbiting scroll compressor body and fixed scroll compressor body increases causing these components to expand. Examples of an apparatus to control such restraint are shown in U.S. Pat. No. 5,407,335, issued to Caillat et al., the entire disclosure of which is hereby incorporated by reference.
Typically, the outer housing is separated to include a high-pressure chamber and a low-pressure chamber by a separator plate. The first compressor member, i.e. the fixed compressor member, is typically positioned within the low-pressure chamber and is fluidly sealed to a port in the separator plate to communicate the high-pressure refrigerant exiting from the scroll compressor to the high-pressure chamber.
At startup, the pressure below the seal is higher than the pressure above the seal for a short period of time. This pressure imbalance causes the seal to move up and a seal spring carried within a seal jacket can be undesirably ejected from the seal jacket.
The present invention is directed towards improvements over the state of the art as it relates to the above-described features and other features of scroll compressors.
To rectify the problems relating to the pressure imbalance and movement of the seals between the fixed compressor member and the separator plate, embodiments of the present invention aim to limit the effects of the pressure imbalance. In one embodiment, a device is provided that limits the axial movement of the seal relative to the fixed compressor member.
In a more particular implementation, a new and improved scroll compressor is provided that limits the axial motion of the seal. In particular, in one embodiment, a scroll compressor including a housing, a separator, a fixed scroll body and a floating seal arrangement is provided. The housing defines an internal cavity. The separator is positioned within the internal cavity of the housing and separates a high pressure chamber from a low pressure chamber. The separator includes a port fluidly communicating with the high pressure chamber. The fixed scroll body is positioned within the low pressure chamber and includes a base, a scroll rib axially extending from a first side of the base, and an axially extending circular hub axially on a second opposite side of the base. The circular hub defines a compression outlet extending through the circular hub and fluidly communicates with the high pressure chamber through the port. The floating seal arrangement is interposed between the fixed scroll body and the separator. The floating seal arrangement seals the compression outlet to the port and is axially moveable relative to the circular hub. The floating seal arrangement includes a floating seal; a first seal interface between the separator and the floating seal; and a second seal interface between the floating seal and the circular hub. The second seal interface includes a first seal member interposed between the circular hub and the floating seal. A seal retaining ring is provided to limit axial movement of the first seal member relative to the circular hub in an axial direction extending away from the base. The seal retaining ring prevents axial motion of the first seal member to prevent degradation of the seal of the first seal interface during initial start-up.
In a more particular embodiment, the floating seal is configured for axial motion relative to the circular hub while remaining in sealing engagement with the first seal member. This allows for increased sealing of the first seal interface and to compensate for thermal expansion/contraction as well as manufacturing tolerances.
In one embodiment, the seal retaining ring is attached to the circular hub limiting axial movement of the seal retaining ring relative to the circular hub as well as axial movement of the first seal member and its components.
In one embodiment, the seal retaining ring has an outer diameter that is greater than an inner diameter of the first seal member when the retaining ring and the first seal member are attached to the fixed scroll body.
In one embodiment, the seal retaining ring has an inner diameter that is less than the inner diameter of the first seal member when the retaining ring and the first seal member are attached to the fixed scroll body.
In one embodiment, the first seal member is a spring energized seal including a resilient seal jacket and a seal spring positioned within the resilient seal jacket.
In a more particular embodiment, the resilient seal jacket is generally U-shaped in cross-section defining opposed seal surfaces. The seal spring is positioned between the opposed seal surfaces.
In an even more particular embodiment, the opposed seal surfaces are a radially outer leg portion and a radially inner leg portion facing generally radially away from one another.
In a more particular embodiment, the seal retaining ring has an outer diameter that is greater than an inner diameter of the radially inner leg portion when the retaining ring and the first seal member are attached to the fixed scroll body.
In another embodiment, the seal retaining ring has an inner diameter that is less than the inner diameter of the radially inner leg portion when the retaining ring and the first seal member are attached to the fixed scroll body. In a further embodiment, the outer diameter of the seal retaining ring is greater than an inner diameter of the seal spring.
In another embodiment, the seal retaining ring covers at least 50 percent of a radial distance defined between the radially inner and outer leg portions.
In one embodiment, the seal retaining ring covers at least 70 percent of a radial distance defined between the radially inner and outer leg portions.
In one embodiment, the radially outer leg portion has an outer diameter that is greater than the outer diameter of the seal retaining ring.
In one embodiment, the circular hub includes a stepped outer radial profile having a first outer surface portion having a first diameter and a second outer surface portion having a second diameter greater than the first diameter. The radially inner leg portion seals against first outer surface portion and the radially outer leg portion is positioned radially outward from the second outer surface.
In one embodiment, the stepped outer radial profile includes a radially extending annular surface extending radially between the first and second outer surface portions. The radially extending annular surface is axially positioned between the seal retaining ring and the base. The first seal member is axially positioned between the radially extending annular surface and the seal retaining ring.
In one embodiment, the U-shaped cross-section of the sealing jacket is provided by a pair of annular sidewalls spaced radially apart forming an annular trough therebetween. The annular sidewalls are connected by a radially extending bottom wall portion at a location opposite distal ends of the pair of annular sidewalls. The distal ends defining a mouth into the annular trough that axially faces the separator plate. The axial distance between a bottom side of the seal retaining ring and a top surface of the bottom wall portion is greater than an axial height of the seal spring.
In one embodiment, the fixed scroll body includes a peripheral rim that is spaced radially outward from and circumscribes the circular hub forming an annular channel therebetween. The floating seal extending axially into the annular channel. The scroll compressor further includes a third seal interface between the floating seal and the peripheral rim. The third seal interface including a second seal member radially interposed between the floating seal and the peripheral rim. The third seal interface permits axial motion between the peripheral rim and the floating seal.
In on embodiment, the base of the fixed scroll body includes disc portion extending radially between the circular hub and the peripheral rim. The disc portion, floating seal arrangement, circular hub and the peripheral rim define a pressure cavity. The disc portion further includes a vent hole passing therethrough allowing pressurization of the pressure cavity.
A method of operating a scroll compressor is also provided. The method provides improved operation that prevents the seal between the fixed scroll body from coming apart due to the pressure differential across the seal interface between the floating seal and the fixed scroll body during startup and the transient pressure state present therein. More particularly, one method includes initiating operation of the scroll compressor; applying a first pressure differential in a first direction for an initial period of time across a seal member sealingly interposed between a fixed scroll body and a floating seal, the first pressure differential biasing the first seal member in a first biased direction. The method further including limiting motion of the first seal member in the first biased direction. The method further includes and applying a second pressure differential across the seal member in a second direction opposite the first direction, subsequent to applying the first pressure differential.
In a further embodiment, the step of opposing motion of the first seal member includes axially trapping the first seal member relative to the fixed scroll body between a portion of the fixed scroll body and an abutment structure. In a preferred embodiment, the abutment structure is a seal retaining ring.
In a further embodiment, the first pressure differential is applied while the scroll compressor is in a transient pressure state (i.e. start-up mode while the pressure is increasing), wherein pressure of fluid downstream of an outlet of the fixed scroll body is less than pressure of fluid within the fixed scroll body and upstream from the outlet of the fixed scroll body. The fluid on a first side of the first seal member is provided downstream from the outlet of the fixed scroll body and the fluid on an opposite side of the first seal member is provided by a vent passing through the fixed scroll body and fluidly in communication with the fluid within the fixed scroll body upstream of the outlet of the fixed scroll body but downstream of an inlet of the fixed scroll body.
Other aspects, objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings:
While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims.
An embodiment of the present invention is illustrated in the figures as a scroll compressor assembly 10 generally including an outer housing 12 in which a scroll compressor 14 can be driven by a drive unit 16. The scroll compressor assembly 10 may be arranged in a refrigerant circuit for refrigeration, industrial cooling, freezing, air conditioning or other appropriate applications where compressed fluid is desired. Appropriate connection ports provide for connection to a refrigeration circuit and include a refrigerant inlet port 18 and a refrigerant outlet port 20 extending through the outer housing 12. The scroll compressor assembly 10 is operable through operation of the drive unit 16 to operate the scroll compressor 14 and thereby compress an appropriate refrigerant or other fluid that enters the refrigerant inlet port 18 and exits the refrigerant outlet port 20 in a compressed high-pressure state.
The outer housing for the scroll compressor assembly 10 may take many forms. In particular embodiments of the invention, the outer housing 12 includes multiple shell sections. In the embodiment of
As can be seen in the embodiment of
Assembly of the outer housing 12 results in the formation of an enclosed chamber 31 that surrounds the drive unit 16, and partially surrounds the scroll compressor 14. In particular embodiments, the top end housing section 26 is generally dome-shaped and includes a respective cylindrical side wall region 32 that abuts the top of the central cylindrical housing section 24, and provides for closing off the top end of the outer housing 12. As can also be seen from
In a particular embodiment, the drive unit 16 in is the form of an electrical motor assembly 40. The electrical motor assembly 40 operably rotates and drives a shaft 46. Further, the electrical motor assembly 40 generally includes a stator 50 comprising electrical coils and a rotor 52 that is coupled to the drive shaft 46 for rotation together. The stator 50 is supported by the outer housing 12, either directly or via an adapter. The stator 50 may be press-fit directly into outer housing 12, or may be fitted with an adapter (not shown) and press-fit into the outer housing 12. In a particular embodiment, the rotor 52 is mounted on the drive shaft 46, which is supported by upper and lower bearing members 42, 44. Energizing the stator 50 is operative to rotatably drive the rotor 52 and thereby rotate the drive shaft 46 about a central axis 54.
Applicant notes that when the terms “axial” and “radial” are used herein to describe features of components or assemblies, they are defined with respect to the central axis 54. Specifically, the term “axial” or “axially-extending” refers to a feature that projects or extends in a direction generally parallel to the central axis 54, while the terms “radial’ or “radially-extending” indicates a feature that projects or extends in a direction generally perpendicular to the central axis 54. Some minor variation from parallel and perpendicular is permissible.
With reference to
In the embodiment of
The drive shaft 46 further includes an offset eccentric drive section 74 that has a cylindrical drive surface 75 (shown in
As shown in
In certain embodiments such as the one shown in
The upper bearing member or crankcase 42 also provides axial thrust support to the movable scroll compressor body 112 through a bearing support via an axial thrust surface 96 of the thrust bearing 84. While, as shown
Turning in greater detail to the scroll compressor 14, the scroll compressor 14 includes first and second scroll compressor bodies which preferably include a stationary fixed scroll compressor body 110 and a movable scroll compressor body 112. While the term “fixed” generally means stationary or immovable in the context of this application, more specifically “fixed” refers to the non-orbiting, non-driven scroll member, as it is acknowledged that some limited range of axial, radial, and rotational movement is possible due to thermal expansion and/or design tolerances.
The movable scroll compressor body 112 is arranged for orbital movement relative to the fixed scroll compressor body 110 for the purpose of compressing refrigerant. The fixed scroll compressor body includes a first scroll rib 114 projecting axially from a plate-like base 116 and is designed in the form of a spiral. Similarly, the movable scroll compressor body 112 includes a second scroll rib 118 projecting axially from a plate-like base 120 and is in the shape of a similar spiral. The scroll ribs 114, 118 engage in one another and abut sealingly on the respective surfaces of bases 120, 116 of the respectively other scroll compressor body 112, 110. As a result, multiple compression chambers 122 are formed between the scroll ribs 114, 118 and the bases 120, 116 of the compressor bodies 112, 110. Within the chambers 122, progressive compression of refrigerant takes place. Refrigerant flows with an initial low pressure via an intake area 124 surrounding the scroll ribs 114, 118 in the outer radial region (see e.g.
The movable scroll compressor body 112 engages the eccentric offset drive section 74 of the drive shaft 46. More specifically, the receiving portion of the movable scroll compressor body 112 includes the cylindrical bushing drive hub 128 which slideably receives the eccentric offset drive section 74 with a slideable bearing surface provided therein. In detail, the eccentric offset drive section 74 engages the cylindrical bushing drive hub 128 in order to move the movable scroll compressor body 112 about an orbital path about the central axis 54 during rotation of the drive shaft 46 about the central axis 54.
Considering that this offset relationship causes a weight imbalance relative to the central axis 54, the assembly typically includes a counterweight 130 that is mounted at a fixed angular orientation to the drive shaft 46. The counterweight 130 acts to offset the weight imbalance caused by the eccentric offset drive section 74 and the movable scroll compressor body 112 that is driven about an orbital path. The counterweight 130 includes an attachment collar 132 and an offset weight region 134 (see counterweight 130 shown best in
With reference to
Referring specifically to
It can be seen in
By virtue of the key coupling 140, the movable scroll compressor body 112 has movement restrained relative to the fixed scroll compressor body 110 along the first lateral axis 146 and second transverse lateral axis 154. This results in the prevention of relative rotation of the movable scroll body as it allows only translational motion. More particularly, the fixed scroll compressor body 110 limits motion of the key coupling 140 to linear movement along the first lateral axis 146; and in turn, the key coupling 140 when moving along the first lateral axis 146 carries the movable scroll compressor body 112 along the first lateral axis 146 therewith.
Additionally, the movable scroll compressor body can independently move relative to the key coupling 140 along the second transverse lateral axis 154 by virtue of relative sliding movement afforded by the guide portions 254 which are received and slide between the second keys 152. By allowing for simultaneous movement in two mutually perpendicular axes 146, 154, the eccentric motion that is afforded by the eccentric offset drive section 74 of the drive shaft 46 upon the cylindrical drive hub 128 of the movable scroll compressor body 112 is translated into an orbital path movement of the movable scroll compressor body 112 relative to the fixed scroll compressor body 110.
To carry axial thrust loads, the movable scroll compressor body 112 also includes flange portions 268 projecting in a direction perpendicular relative to the guiding flange portions 262 (e.g. along the first lateral axis 146). These additional flange portions 268 are preferably contained within the diametrical boundary created by the guide flange portions 262 so as to best realize the size reduction benefits. Yet a further advantage of this design is that the sliding faces of guide portions 254 of the movable scroll compressor body 112 are open and not contained within a slot. This is advantageous during manufacture in that it affords subsequent machining operations such as finishing milling for creating the desirable tolerances and running clearances as may be desired.
Generally, scroll compressors with movable and fixed scroll compressor bodies require some type of restraint for the fixed scroll compressor body 110 which restricts the radial movement and rotational movement but which allows some degree of axial movement so that the fixed and movable scroll compressor bodies 110, 112 are not damaged during operation of the scroll compressor 14. In embodiments of the invention, that restraint is provided by a pilot ring 160, as shown in
A second inner wall 189 runs along the inner diameter of each semi-circular stepped portion 164. Each semi-circular stepped portion 164 further includes a bottom surface 191, a notched section 166, and a chamfered lip 190. In the embodiment of
In the embodiment of
The fixed scroll compressor body 110 also has a pair of second radially-outward projecting limit tabs 113, which, in this embodiment, are spaced approximately 180 degrees apart. In certain embodiments, the second radially-outward projecting limit tabs 113 share a common plane with the first radially-outward-projecting limit tabs 111. Additionally, in the embodiment of
Referring still to
Though not visible in the view of
It should be noted that “limit tab” is used generically to refer to either or both of the radially-outward projecting limit tabs 111, 113. Embodiments of the invention may include just one of the pairs of the radially-outward projecting limit tabs, or possibly just one radially-outward projecting limit tab, and particular claims herein may encompass these various alternative embodiments
As illustrated in
It is contemplated that the embodiments of
With reference to
In the embodiment shown, to accommodate the floating seal 170, the upper side of the fixed scroll compressor body 110 includes an annular and, more specifically, the cylindrical inner hub region 172, and the peripheral rim 174 spaced radially outward from and circumscribing the inner hub region 172 forming annular channel 210 therebetween. The inner hub region 172 and the peripheral rim 174 are connected by a radially-extending disc region 176 of the base 116. The inner hub region 172 defines a compression outlet 126 through which the high-pressure refrigerant exits the scroll compressor 14.
As shown in
In a particular embodiment of the invention, a central region of the floating seal 170 includes a plurality of openings 175 and 177. Central opening 177 is centered on the central axis 54. That central opening 177 is adapted to receive a rod 181 which is affixed to the floating seal 170.
As shown in
As can be seen in
The floating seal arrangement 159 acts to fluidly seal the fixed scroll compressor body 110 to the separator plate 30 and particularly the compression outlet 126 of the scroll compressor 14 to the center hole 33 of the separator plate 30, which is in fluid communication with the high pressure chamber 180.
In certain embodiments, when the floating seal 170 is axially installed, at least in part, within the annular channel 210 between the inner hub region 172 and the peripheral rim 174, the cavity 272 beneath the floating seal 170 is pressurized by a vent hole 274 drilled through the fixed scroll compressor body 110 to chamber 122. This pushes the floating seal 170 up towards the separator plate 30 (shown in
While the separator plate 30 could be a stamped steel component, it could also be constructed as a cast and/or machined member (and may be made from steel or aluminum) to provide the ability and structural features necessary to operate in proximity to the high-pressure refrigerant gases output by the scroll compressor 14. By casting or machining the separator plate 30 in this manner, heavy stamping of such components can be avoided.
The floating seal arrangement 159 further includes a first seal interface 214 between the separator plate 30 and the floating seal 170. In the illustrated embodiment, the first seal interface 214 is an axial seal arrangement including the flat, annular washer-shaped gasket 216 axially compressed between the separator plate 30 and the circular rib 182 portion of the floating seal 170 extending axially towards the separator plate 30.
Referring to
The floating seal arrangement 159 includes a second seal interface 224 between the floating seal 170 and the inner hub region 172. The second seal interface 224 includes a first seal member in the form of a spring energized seal 226 radially interposed between an outward facing radially outer seal surface of the inner hub region 172 and a radially inner seal surface 228 of the floating seal 170. The radially inner seal surface 228 is formed by a sidewall defining the circular cutout 209. The inclusion of seal interfaces 214 and 224 seal the fixed scroll compressor body 110 to the separator plate 30.
A seal retaining ring 230 limits axial movement of the spring energized seal 226 relative to the inner hub region 172 in a direction (illustrated by arrow 232) extending away from the base 116 of fixed scroll compressor body 110 during initial start-up, which will be more fully described below. The seal retaining ring 230 is mounted in an annular mounting groove 234 that has a radially outward directed mouth that radially receives a radially inner portion of the seal retaining ring 230. The seal retaining ring 230 is mounted in a generally cantilevered orientation extending radially outward beyond the radially outer sealing surface of the inner hub region 172. The seal retaining ring 230 is prevented from moving axially relative to inner hub region 172.
The spring energized seal 226 generally includes a generally U-shaped resilient seal jacket 236 carrying a seal spring 238 within the annular channel formed by the U-shaped resilient seal jacket 236. Axially extending leg portions 240, 242 (also referred to as sidewalls) are connected by a radially extending bottom wall portion 243. Leg portions 240, 242 and bottom wall portion 243 define the annular channel, also referred to as a trough, therebetween. The annular channel has an axially facing mouth that opens towards the separator plate 30. The leg portions 240, 242 are connected to the bottom wall portion 243 at a location opposite distal ends thereof. The distal ends of the leg portions 240, 242 define the mouth of the annular channel. In one embodiment, the axial distance between a bottom side of the seal retaining ring 230, i.e. the side that faces the spring energized seal 226, and a top surface of the bottom wall portion 243, i.e. the bottom of the annular channel, is greater than an axial height of the seal spring 238.
Each leg portion 240, 242 defines a radially facing seal surface. These seal surfaces are opposed seal surfaces that face in opposite radial directions and away from one another and have the seal spring 238 positioned radially therebetween. Leg portion 240 defines a radially inward directed seal surface that radially seals with the radially outward facing seal surface of inner hub region 172. Leg portion 242 defines a radially outward facing seal surface that radially seals with radially inner seal surface 228 of the floating seal 170.
The seal retaining ring 230 has an outer diameter that is greater than an inner diameter of the spring energized seal 226 and particularly the inner seal surface thereof when the spring energized seal 226 is mounted to the inner hub region 172. Due to the mounting arrangement of the seal retaining ring 230 relative to inner hub region 172, the seal retaining ring 230 has an inner diameter that is less than the inner diameter of the spring energized seal 226, and particularly the radially inner seal surface, when the spring energized seal 226 is attached to the fixed scroll compressor body 110 and particularly inner hub region 172.
In the illustrated embodiment, the seal retaining ring 230 and the spring energized seal 226 are configured such that the outer diameter of the seal retaining ring 230 is greater than an inner diameter of the seal spring 238. As such, the seal retaining ring 230 axially limits travel of both the resilient seal jacket 236 and the seal spring 238. In one embodiment, the seal retaining ring 230 extends radially outward at least 50% the radial distance between the inner seal surface defined by leg portion 240 and the outer seal surface defined by leg portion 242. More preferably, the seal retaining ring 230 extends radially outward at least 70% the radial distance between the inner seal surface defined by leg portion 240 and the outer seal surface defined by leg portion 242. In one embodiment, the outer diameter of the spring energized seal 226 defined by the radially outer seal surface of the radially outer leg portion 242 is greater than the outer diameter of the seal retaining ring 230. Preferably, seal retaining ring 230 does not contact seal surface 228 of floating seal 170.
The inner hub region 172 has a generally stepped profile having a first outer surface portion 250 having an outer diameter and second outer surface portion that is provided, generally, by the radially outward facing seal surface 251, which has a diameter that is less than the outer diameter of first outer surface portion 250. The radially inner seal surface of leg portion 240 seals against the seal surface 251 and the radially outer seal surface provided by leg portion 242 generally extends radially outward beyond the first outer surface portion 250 such that it can engage and seal with seal surface 228 of floating seal 170. The stepped profile includes a radially extending annular surface 253 extending radially between surface portions 250, 251. The radially extending annular surface is axially positioned between the seal retaining ring 230 and base 116 and axially faces the seal retaining ring 230. The spring energized seal 236 is axially positioned between the radially extending annular surface 253 and the seal retaining ring 230.
A third seal interface 260 is radially interposed between the floating seal 170 and the peripheral rim 174. The third seal interface 260 includes a second spring energized seal 263 radially positioned between a radially outward facing seal surface 264 of the floating seal 170 proximate the outer radial periphery thereof and a radially inward facing seal surface 266 of the peripheral rim 174. An undercut is provided proximate radially outward facing seal surface 264 that axially locates and secures the second spring energized seal 263 relative to a stepped region of the radially outer periphery of the floating seal 170.
The base 116, and particularly disc portion 176 thereof, floating seal arrangement 159, inner hub region 172 and the peripheral rim 174 define a pressure cavity 272 therebetween. The disc portion 176 includes a vent hole 274 passing axially therethrough which communicates an upper side of the disc portion 176 with a bottom side (i.e. the side with the scroll rib) of the disc portion 176. This vent hole 274 allows for pressurization of the pressure cavity 272 to force the floating seal 170 towards the separator plate 30 improving the seal at the first seal interface 214.
As can now be understood, the floating seal arrangement 159 is configured to allow the floating seal 170 to have limited axial movement relative to the fixed scroll compressor body 110 due to the inclusion of the second and third seal interfaces 224, 260. This allows for the slight axial movement/displacements/expansion/tolerances of the components of the scroll compressor 14 during operation.
Further, during start-up operations, the pressure cavity 272 is initially exposed to a higher pressure than the area defined by compression outlet 126 and center hole 33. As such, a first pressure differential acts across the second seal interface 224. This pressure differential results in a low pressure above the spring energized seal 226 and a high pressure below the spring energized seal 226 within pressure cavity 272.
The inclusion of the seal retaining ring 230 axially traps the spring energized seal 226 and limits motion of the spring energized seal 226 preventing the seal spring 238 from coming axially out of the resilient seal jacket 236. Thus, the use of the seal retaining ring 230 allows the use of a spring energized seal 226 for proper sealing action while opposing ejection of the seal spring from the seal jacket.
After start-up, the pressure above the second seal interface 224 is greater than within the pressure cavity 272 such that the pressure differential acts in the opposite direction as during initial start-up while the pressure within the scroll compressor 14 is transient. This is because the pressure above the second seal interface 224 is at the high pressure created by the scroll compressor 14 while the pressure within pressure cavity 272 is at an intermediate pressure due to the location of the vent hole 274 positioned between the inlet and outlet of scroll compressor 14. Therefore, the fluid pressurizing the pressure cavity 272 has not been fully pressurized by the scroll compressor 14 as compared to the fluid at the compression outlet 126 which acts on the opposite side of the second seal interface 224. Once the pressure above the second seal interface 224 is greater, motion of the spring energized seal 226 is limited.
During operation, the scroll compressor assembly 10 is operable to receive low-pressure refrigerant at the housing inlet port 18 and compress the refrigerant for delivery to the high-pressure chamber 180 where it can be output through the housing outlet port 20. This allows the low-pressure refrigerant to flow across the electrical motor assembly 40 and thereby cool and carry away from the electrical motor assembly 40 heat which can be generated by operation of the motor. Low-pressure refrigerant can then pass longitudinally through the electrical motor assembly 40, around and through void spaces therein toward the scroll compressor 14. The low-pressure refrigerant fills the chamber 31 formed between the electrical motor assembly 40 and the outer housing 12. From the chamber 31, the low-pressure refrigerant can pass through the upper bearing member or crankcase 42 through the plurality of spaces 244 that are defined by recesses around the circumference of the crankcase 42 in order to create gaps between the crankcase 42 and the outer housing 12. The plurality of spaces 244 may be angularly spaced relative to the circumference of the crankcase 42.
After passing through the plurality of spaces 244 in the crankcase 42, the low-pressure refrigerant then enters the intake area 124 between the fixed and movable scroll compressor bodies 110, 112. From the intake area 124, the low-pressure refrigerant enters between the scroll ribs 114, 118 on opposite sides (one intake on each side of the fixed scroll compressor body 110) and is progressively compressed through chambers 122 until the refrigerant reaches its maximum compressed state at the compression outlet 126 from which it subsequently passes through the floating seal 170 via the plurality of openings 175 and into the high-pressure chamber 180. From this high-pressure chamber 180, high-pressure compressed refrigerant then flows from the scroll compressor assembly 10 through the housing outlet port 20.
As is evident from the exploded view of
All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.