Patent ID: 12241467

DETAILED DESCRIPTION OF THE INVENTION

Referring to theFIGS.1A-20D, wherein like numerals indicate like or corresponding parts throughout the several views, an electric compressor10having an outer housing12is provided. The electric compressor10is particularly suitable in a motor vehicle, such as an automotive vehicle (not shown). The electric compressor10may be used as a cooling device or as a heating pump (in reverse) to heat and/or cool different aspects of the vehicle. For instance, the electric compressor10may be used as part of the heating, ventilation and air conditioning (HVAC) system in electric vehicles (not shown) to cool or heat a passenger compartment. In addition, the electric compressor10may be used to heat or cool the passenger compartment, on-board electronics and/or a battery used for powering the vehicle while the vehicle is not being operated, for instance, during a charging cycle. The electric compressor10may further be used while the vehicle is not being operated and while the battery is not being charged to maintain, or minimize the degradation, of the life of the battery. In the illustrated embodiment, the electric compressor10has a capacity of 36 cubic centimeters (cc). The capacity refers to the initial volume captured within the compression device as the scrolls of the compression device initially close or make contact (see below). It should be noted that the electric compressor10disclosed herein is not limited to any such volume and may be sized or scaled to meet particular required specifications.

In the illustrated embodiment, the electric compressor10is a scroll-type compressor that acts to compress a refrigerant rapidly and efficiently for use in different systems of a motor vehicle, for example, an electric or a hybrid vehicle. The electric compressor includes10an inverter section14, a motor section16, and a compression device (or compression assembly)18contained within the outer housing12. The outer housing12includes an inverter back cover20, an inverter housing22, a center housing24, and a front cover28(which may be referred to as the discharge head). The center housing24houses the motor section16and the compression device28.

In one aspect of the present invention, the electric compressor10includes a cylindrical sleeve170encompassing the motor section16configured to constrain the motor section16within the outer housing12(see below).

The inverter back cover20, the inverter housing22, the center housing24, and the front cover28may be composed from machined aluminum. The inverter10may be mounted, for example, within the body of a motor vehicle, via a plurality of mount points120.

General Arrangement, and Operation, of the Electric Compressor10

The inverter back cover20and the inverter housing22form an inverter cavity30. The inverter back cover20is mounted to the inverter housing22by a plurality of bolts32. The inverter back cover20and the inverter housing22are mounted to the center housing24by a plurality of bolts34which extend through apertures36in the inverter back cover20and apertures38in the inverter housing22and are threaded into threaded apertures40in the center housing24. An inverter gasket42, positioned between the inverter back cover20and the inverter housing22keeps moisture, dust, and other contaminants from the internal cavity30. A motor gasket54B is positioned between the inverter housing22and the center housing24to provide and maintain a refrigerant seal to the environment.

With reference toFIG.11, an inverter module44mounted within the inverter cavity30formed by the inverter back cover20and the inverter housing22. The inverter module44includes an inverter circuit46mounted on a printed circuit board48, which is mounted to the inverter housing22. The inverter circuit46converts direct current (DC) electrical power received from outside of the electric compressor10into three-phase alternating current (AC) power to supply/power the motor54(see below). The inverter circuit46also controls the rotational speed of the electric compressor10. High voltage DC current is supplied to the inverter circuit46via a high voltage connector50. Low voltage DC current to drive the inverter circuit46, as well as control signals to control operation of the inverter circuit46, and the motor section16, is supplied via a low voltage connector52.

The center housing24forms a motor cavity56. The motor section16includes a motor54located within the motor cavity56. The motor cavity56is formed by a motor side22A of the inverter housing22and an inside surface24A of the center housing22. With specific reference toFIG.12, the motor54is a three-phase AC motor having a stator60. The stator60has a generally hollow cylindrical shape with six individual coils (two for each phase). The stator60is contained within, and mounted to, the motor housing22and remains stationary relative to the motor housing22.

The motor54includes a rotor60located within, and centered relative to, the stator58. The rotor60has a generally hollow cylindrical shape and is located within the stator60. The rotor60has a number of balancing counterweights60A,60B, affixed thereto. The balancing counterweights balance the motor54as the motor54drives the compression device18and may be machined from brass.

Power is supplied to the motor54via a set of terminals54A which are sealed from the motor cavity56by an O-ring54B.

A drive shaft90is coupled to the rotor60and rotates therewith. In the illustrated embodiment, the draft shaft90is press-fit within a center aperture60C of the rotor60. The drive shaft90has a first end90A and a second end90B. The inverter housing22includes a first drive shaft supporting member22B located on the motor side of the inverter housing22. A first ball bearing62located within an aperture formed by the first drive shaft supporting member22supports and allows the first end of the drive shaft90to rotate. The center housing24includes a second drive shaft supporting member24A. A second ball bearing64located within an aperture formed by the second drive shaft supporting member24A allows the second end90B of the drive shaft90to rotate. In the illustrated embodiment, the first and second ball bearing62,64are press-fit with the apertures formed by the first drive shaft supporting member22of the inverter housing22and the second drive shaft supporting member24A of the center housing24, respectively.

As stated above, the electric compressor10is a scroll-type compressor. The compression device18includes the fixed scroll26and an orbiting scroll66. The orbiting scroll66is fixed to the second end of the rotor60B. The rotor60with the drive shaft90rotate to drive the orbiting scroll66motion under control of the inverter module44rotate.

With reference toFIGS.14A,14B,16A and16B, the drive shaft90has a central axis90C around which the rotor60and the drive shaft90are rotated. The orbiting scroll66moves about the central axis90C in an eccentric orbit, i.e., in a circular motion while the orientation of the orbiting scroll66remains constant with respect to the fixed scroll26. The center of the orbiting scroll66is located along an offset axis90D of the drive shaft90defined by an orbiting scroll aperture (or drive pin location)90E (seeFIG.14A) located at the second end90D of the drive shaft90. As the drive shaft90is rotated by the motor54, the orbiting scroll66follows the motion of the orbiting scroll aperture90E through the drive pin126and the drive hub of the swinglink mechanism124and bearing108as the drive shaft90is rotated about the central axis60C.

With specific reference toFIGS.1,2and9, intermixed refrigerant and oil (at low pressure) enters the electric compressor10via a refrigerant inlet port68and exits the electric compressor10(at high pressure) via refrigerant outlet port70after being compressed by the compression device18. As shown in the cross-sectional view ofFIG.9, the refrigerant follows the refrigerant path72through the electric compressor10. As shown, refrigerant enters the refrigerant inlet port68and enters an intake volume74formed between the motor side22A of the inverter housing22and the center housing24adjacent the refrigerant inlet port68. Refrigerant is then drawn through the motor section16and enters a compression intake volume76formed between an internal wall of the fixed scroll26and the orbiting scroll66(demonstrated by arrow92inFIG.14A).

The fixed scroll26is mounted within the center housing24. As shown inFIGS.9and13, the fixed scroll26has a fixed scroll base26A and a fixed scroll lap26B extending away from the fixed scroll base26A towards the orbiting scroll66. As shown inFIGS.16A-16B, the orbiting scroll66has an orbiting scroll base66A and an orbiting scroll lap66B extending from the orbiting scroll base66A towards the fixed scroll26. The laps26A,66A have a tail end26C,66C adjacent an outer edge of the respective scroll26A,66B and scroll inward towards a respective center end26D,66D.

Respective tip seals94are located within a slot26E,66E located at a top surface of the fixed scroll26and the orbiting scroll66, respectively. The tip seals94are comprised of a flexible material, such as a Polyphenylene Sulfide (PPS) plastic. When assembled, the tip seals94are pressed against the opposite base26A66A to provide a seal therebetween. In one embodiment, the slots26E66E, are longer than the length of the tip seals94to provide room for adjustment/movement along the length of the tip seals94.

With reference toFIGS.17A-17I, refrigerant enters the compression device12from the compression intake volume76. InFIGS.17A-17I, a cross-section view of the fixed scroll26shown and the top of the orbiting scroll66are shown.

As discussed in detail below, the fixed scroll lap26A and the orbiting scroll lap66A form compression chambers80in which low or unpressurized (saturation pressure) refrigerant enters from the compression device12. As the orbiting scroll66moves to enable the compression chambers80to be closed off and the volume of the compression chambers80is reduced to pressurize the refrigerant. At any one time during the cycle, one or more compression chambers80are at different stages in the compression cycle. The below description relates just to one set of compression chambers80during a complete cycle of the electric compressor10.

The refrigerant enters the compression chambers80formed between the orbiting scroll lap66A and the fixed scroll lap26A. During a cycle of the compressor10, the refrigerant is transported towards the center of these chambers. The orbiting scroll66orbits in a circular motion indicated by arrow78formed by the relative position of the orbiting scroll66relative to the fixed scroll26is shown during one cycle of the electric compressor10.

InFIG.17A, the position of the orbiting scroll66at the beginning of a cycle is shown. As shown, in this initial position, the tail ends16B,66B are spaced apart from the other scroll lap66B16B. At this point, the compression chambers80are open to the compression intake volume76allowing refrigerant under low pressure to fill the compression chambers80from the compression intake volume76. As the orbiting scroll66moves along path78, the space between the tail ends16A,66A and the other scroll66,16decreases until the compression chambers80are closed off from the compression intake volume76(FIGS.17B-17E). As the orbiting scroll66continues to move along78, the volume of the compression chambers80is further reduced, thus pressurizing the refrigerant in both compression chambers80(FIGS.17F-H). As shown inFIGS.17I-18J, as the orbiting scroll66continues to orbit, the two compression chambers80are combined into a single volume. This volume is further reduced until the pressurized refrigerant is expelled from the compression device18(see below)

As discussed below, the refrigerant enters chambers formed between the walls of the orbiting scroll66and the fixed scroll26. During the cycle of the compressor10, the refrigerant is transported towards the center of these chambers. The orbiting scroll66orbits or moves in a circular motion indicated by arrow78formed by the relative position of the orbiting scroll66relative to the fixed scroll26is shown during one cycle of the electric compressor10.

Returning toFIG.1, the front cover28forms a discharge volume82. The discharge volume82is in communication with the refrigerant output port70. As discussed in more detail below, pressurized refrigerant leaves the compression device18through a central orifice84A and two side orifices84B in the fixed scroll26(seeFIGS.18C and18E) The release of pressurized refrigerant is controlled by a reed mechanism86. In the illustrated embodiment, the reed mechanism86includes three reeds: a central reed87A and two side reeds87B corresponding to the central orifice84A and the two side orifices84B (see below).

As shown inFIGS.18D and18E, in the illustrated embodiment, the reed mechanism86includes a discharge reed86A and a reed retainer86B. The discharge reed86A is made from a flexible material, such as steel. The characteristics, such as material and strength, are selected to control the pressure at which the pressurized refrigerant is released from the compression device18. The reed retainer86B is made from a rigid, inflexible material such as stamped steel. The reed retainer86controls or limits the maximum displacement of the discharge reed86A relative to the fixed scroll26. Generally, oil is directed rearward through the motor section16, providing lubrication and cooling to the rotating components of the electric compressor10, such as the rotor60, the drive shaft90and all beatings62,64,108. Oil is drawn upward towards the top of the motor54by the rotation of the rotor60. From there, oil enters the interior of the motor54to lubricate the second ball bearing64and the oil by the rotational forces within the motor section16may impact against the motor side22A of the inverter housing22. The oil is further directed by the motor side22A into the ball bearing62, further discussed below

In the illustrated embodiment, the read mechanism86is held or fixed in place via a separate fastener89. As shown inFIGS.18E and18F, the reed mechanism86incudes a plurality of apertures86C which are configured to receive associated posts83A on the fixed scroll26. As shown inFIG.18E, the back surface of the fixed scroll26includes a bezel83B surrounding the orifices84which assists in tuning the pressure at which refrigerant exits the compression device18. Additionally, a debris collection slot83C collects debris near the orifices84A,84B to prevent from interference with the reed mechanism86.

As shown inFIG.9, the path of refrigerant through the electric compressor is indicated by dashed arrow72.

The electric compressor10utilizes oil (not shown) to provide lubrication to the between the components of the compression device18and the motor54, for example, between the orbiting scroll66and the fixed scroll26and within the ball bearings62,64. The oil intermixes with the refrigerant within the compression device18and the motor54and exits the compression device18via the orifice84. As discussed in more detail below, the oil is separated from the compressed refrigerant within the front cover28and is returned to the compression device18.

An oil separator96facilitates the separation of the intermixed oil and refrigerant. In the illustrated embodiment, the oil separator96is integrated within the front cover28. The front cover28further defines an oil reservoir98which collects oil from the oil separator96before the oil is recirculated through the motor54and motor cavity56and the compression device18. In use, the electric compressor10is generally orientated as shown inFIGS.3-5, such that gravity acts as indicated by arrow106and oil collects within the oil reservoir98.

With reference toFIG.9, the general path oil travels from the bottom of the electric compressor10through the compression device18, out the orifice84to the discharge volume82of the front cover28and back to the compression device18is shown by arrow88.

In the illustrated embodiment, the front cover28is mounted to the center housing24by a plurality of bolts122inserted through respective apertures therein and threaded into apertures in the center housing24. A fixed head gasket110and a rear heard gasket112, are located between the center housing24and the fixed scroll26to provide sealing.

An oil separator96facilitates the separation of the intermixed oil and refrigerant. Generally, the oil separator96only removes some of the oil within the intermixed oil and refrigerant. The separator oil is stored in an oil reservoir and cycled back through the compression device18, where the oil is mixed back in with the refrigerant.

In the illustrated embodiment, the oil separator96is integrated within the front cover28. The front cover28further defines an oil reservoir98which collects oil from the oil separator96before the oil is recirculated through the motor54and motor cavity56and the compression device18. In use, the electric compressor10is generally orientated as shown inFIGS.3-5, such that gravity acts as indicated by arrow106and oil collects within the oil reservoir98. With reference toFIG.9, the general path oil travels from the bottom of the electric compressor10through the compression device18, out the orifice84to the discharge volume82of the front cover28and back to the compression device18is shown by arrow88. As shown, the oil is drawn back up into the compression device18where the oil mixed back into or with the refrigerant.

As stated above, refrigerant, which is actually a mixture of refrigerant and oil enters the electric compressor10via the refrigerant inlet port70. The intermix of oil and refrigerant is drawn into the motor section16, thereby providing lubrication and cooling to the rotating components of the electric compressor10, such as the rotor60, the drive shaft90. Oil and refrigerant enters the interior of the motor54to lubricate the second ball bearing64and the oil by the rotational forces within the motor section16, may impact against the motor side22A of the inverter housing22. The refrigerant and oil is further directed by the motor side22A into the ball bearing62, further discussed below.

Swing-Link Mechanism and Concentric Protrusion of the Drive Shaft

With specific reference toFIGS.13-18B, in a first aspect of the electric compressor10of the disclosure, an electric compressor10includes a swing link mechanism124and the drive shaft90has a concentric protrusion126. In one embodiment, the concentric protrusion126is integrally formed with the drive shaft90. As discussed below, the swing-link mechanism124is used to rotate the orbiting scroll66in an eccentric orbit about the drive shaft90.

In the prior art, the drive shaft is coupled to a swing-link mechanism by a drive pin and a separate eccentric pin, both of which are pressing into the drive shaft. The drive pin is used to rotate the swing link mechanism124which moves the orbiting scroll66along its eccentric orbit. The drive pin and the eccentric pin are inserted into respective apertures in the end of the drive shaft. The eccentric pin is used to limit articulation of the orbiting scroll66is the orbiting scroll66travels along the eccentric orbit. Neither the drive pin, nor the eccentric pin, are located along the central axis of the drive shaft. As the drive shaft is rotated, the drive pin and the eccentric pin are placed under considerable stress. This, both pins are composed from a hardened material, such as SAE 52100 bearing steel. In addition, the eccentric pin may require an aluminum bushing or other slide bearing to prevent damage to the eccentric pin, as the eccentric pin is used to limit the radial movement of the eccentric orbit of the orbiting scroll66. Also, the prior art eccentric pin requires additional machining on the face of the drive shaft90, including precise apertures for the drive pin, and eccentric pin.

As discussed in more detail below, the eccentric pin of the prior art is replaced with a concentric protrusion90F.

In the illustrated embodiment, the scroll-type electric compressor10includes the housing12, the refrigerant inlet port68, the refrigerant outlet port70, the drive shaft90, the concentric protrusion90F, the motor54, the compression device18, the swing link mechanism124, a drive pin126and a ball bearing108. The housing12defines the intake volume74and the discharge volume82. The refrigerant inlet port68is coupled to the housing12and is configured to introduce the refrigerant to the intake volume74. The refrigerant outlet port70is coupled to the housing12and is configured to allow compressed refrigerant to exit the scroll-type electric compressor10from the discharge volume82. The drive shaft90is located within the housing12and has first and second ends90A,90B. The drive shaft90defines, and is centered upon, a center axis90C.

The concentric protrusion90F is located at the second end90B of the drive shaft90and is centered on the center axis90C. The concentric protrusion90F and extends away from the drive shaft90along the central axis90C. The concentric protrusion90F includes a drive pin aperture90E. The motor54is located within the housing12and is coupled to the drive shaft90to controllably rotate the drive shaft90about the center axis90C. The drive pin126is located within the drive pin aperture90E and extends away from the drive shaft90. The drive pin126is parallel to the concentric protrusion90F.

The concentric pin90F may further include an undercut90G, and the outer surface may be surface hardened or after treated with a coating or bearing surface. The concentric pin90F may be further machined simultaneously with the drive shaft90.

As explained above, the compression device18includes the fixed scroll26and the orbiting scroll66. The fixed scroll26is located within, and being fixed relative to, the housing12. The orbiting scroll66is coupled to the drive shaft90. The orbiting scroll66and the fixed scroll26form compression chambers80(see above) for receiving the refrigerant from the intake volume74and for compressing the refrigerant as the drive shaft90is rotated about the center axis90C. The orbiting scroll66has an inner circumferential surface66E.

The swing-link mechanism124is coupled to the drive shaft90and has first and second apertures124A,124B for receiving the concentric protrusion90F and the drive pin126. The swing-link mechanism124further includes an outer circumferential surface124C.

The ball bearing108is positioned between, and adjacent to each of, the inner circumferential surface66E of the orbiting scroll66and the outer circumferential surface124C of the swing-link mechanism124. The drive shaft90, drive pin126, orbiting scroll66and swing-link mechanism124are arranged to cause the orbiting scroll66to rotate about the central axis90C in an eccentric orbit.

In one embodiment, the concentric protrusion90F is integrally formed with the drive shaft90. The drive shaft90, concentric protrusion90F, and swing-link mechanism124may be machined from steel. The concentric protrusion90F being formed simultaneously and within the same machining operation with the drive shaft90further increases manufacturing efficiencies.

The expanded view of a portion of the compression device18illustrated inFIG.16G, further illustrates the concentric protrusion90F. The concentric protrusion90F interacts and guides the swink-link mechanism124. The concentric protrusion90F is sized and machined with a controlled tolerance with the first aperture124A to create a controlled gap that limits the radial movement of the eccentric orbit of the orbiting scroll66. Unlike the prior art, the concentric protrusion90F does not require a second pin, or any additional machining operations. The concentric protrusion90F further co-operates with the guidance pins128and the slots66G on a lower surface66F of the orbiting scroll66, further discussed below.

The scroll-type electric compressor10includes an inverter section14, a motor section16, and the compression device18. The motor section16includes a motor housing54that defines a motor cavity56. The compression section18includes the fixed scroll26. The housing12is formed, at least in part, the fixed scroll26and the center housing24.

With specific reference to13,16B, and18A-18F in the illustrated embodiment, the orbiting scroll66has a lower surface66F. The lower surface66F has a plurality of ring-shaped slots66G. The center housing24includes a plurality of articulating guidance pin apertures128. The guidance pins128are located within the guidance pin apertures66G and extend towards the compression device18and into the ring-shaped slots66G. The guidance pins128are configured to limit articulation of the orbiting scroll66as the orbiting scroll66orbits about the central axis90C. In one embodiment, each of the ring-shaped slots66G includes a ring sleeve118. A thrust plate130is located between the fixed scroll26and a thrust body150(see below) and provides a wear surface therebetween.

Discharge Head Design Having a Three-Reed Reed Mechanism and an Oil Separator

In the illustrated embodiment, the electric compressor10includes a multicavity pulsation muffler system160and an oil separator96which may be located in the discharge volume82and integrally formed with the discharge head or front cover28. As discussed above, oil is used to provide lubrication between the moving components of the electric compressor10. During operation, the oil and the refrigerant become mixed. The oil separator96is necessary to separate the intermixed oil and refrigerant before the refrigerant leaves the electric compressor10.

Generally, refrigerant is released from the compression device18during each cycle, i.e., revolution (or orbit) of the orbiting scroll66. In the illustrated embodiment, refrigerant leaves the compression device18through the central orifice84A and two side orifices84B in the fixed scroll26. Release of the refrigerant through the orifices,84A,84B is controlled by the central reed87A and two side reeds87B, respectively. The multicavity pulsation muffler system160and the oil separator96are described in more detail below.

Scroll Bearing Oil Orifice

The electric compressor10may include a scroll bearing oil injection orifice. As discussed above, the compression device18of the present disclosure includes a ball bearing108. In the illustrated embodiments, the ball bearing108is located between the swing-link mechanism124and the orbiting scroll66. However, as a result of the location of the ball bearing108within the compression device18, there may be limited oil delivery to the ball bearing108resulting in reduced durability. As shown inFIG.9, the oil orifice138allows oil (and refrigerant) to travel from the discharge chamber82to the ball bearing108along the path73(which may be referred to as the “nose bleed” path).

The scroll-type electric compressor10may include a housing12, a refrigerant inlet port68, a refrigerant outlet port70, an inverter module144, a motor54, a drive shaft90and a compression device18. The housing12defines an intake volume74and a discharge volume82. The refrigerant inlet port68is coupled to the housing12and is configured to introduce the refrigerant to the intake volume74. The refrigerant outlet port70is coupled to the housing12and is configured to allow compressed refrigerant to exit the scroll-type electric compressor10from the discharge volume82. The inverter module144is mounted inside the housing12and adapted to convert direct current electrical power to alternating current electrical power. The motor54is mounted inside the housing12. The drive shaft90is coupled to the motor54. The compression device18receives the refrigerant from the intake volume74and compresses the refrigerant as the drive shaft90is rotated by the motor54. The compression device18includes a fixed scroll26, an orbiting scroll66, a swing-link mechanism124, a ball bearing108and a pin136.

The fixed scroll26is located within, and is fixed relative to, the housing12. The orbiting scroll66is coupled to the drive shaft90. The orbiting scroll66and the fixed scroll26form compression chambers80for receiving the refrigerant from the intake volume72and compressing the refrigerant as the drive shaft90is rotated about the center axis90C. The orbiting scroll66has a first side (or the lower surface)66F and a second side (or upper surface)66G. The orbiting scroll66has an oil aperture140through the orbiting scroll66from the first side66F to the second side66G.

The swing-link mechanism124is coupled to the drive shaft90. The ball bearing108is positioned between and adjacent to each of the orbiting scroll66and the swing-link mechanism124. The drive shaft90, orbiting scroll66and swing-link mechanism124are arranged to cause the orbiting scroll66to orbit the central axis90C in an eccentric orbit.

As shown inFIGS.16B-16E, the tip of the orbiting scroll66includes a plug136and has an oil orifice138. The plug136may be press fit within the oil aperture140of the orbiting scroll66. The oil orifice138is configured to allow oil with a controlled flow rate or compressed refrigerant to pass through the orbiting scroll66to the ball bearing108.

The size of the oil orifice138may be tuned to the specifications of the electric compressor10. For example, given the specifications of the electric compressor10, the diameter of the oil orifice138may be chosen such that only oil is allowed to pass through and to limit the equalization of pressure between the first and second sides of the orbiting scroll66. By using a separate plug136, rather than machining the oil orifice138directly in the orbiting scroll66, manufacturing efficiencies may be achieved. And the plug136may have an oil orifice138that is specifically designed and tuned to allow for oil flow and refrigerant flow to increase or decrease depending on the diameter and geometry of the oil orifice138.

As shown inFIGS.16D-16E, in one embodiment, the oil orifice138may have a first bore138A and a second bore138B, wherein a diameter of the first bore138A is less than a diameter of the second bore138B. For example, in one application of this embodiment the first bore138A has an approximate diameter of 0.3 mm. The second bore138B has a diameter greater than the diameter of the first bore138A and is only used to shorten the length of the first bore138A. The flow of the oil and coolant is designed to provide thermal and lubricant to the ball bearing108supporting the radial forces created by the eccentric orbit of the orbiting scroll66.

Further, as discussed above, the orbiting scroll66has an orbiting scroll base66A and an orbiting scroll lap66B. The orbiting scroll lap66B may have an orbiting scroll tail end66C and an orbiting scroll center end66D. As shown, the oil aperture140is located within the orbiting scroll center end66D. The plug136may be secured into the oil aperture140, by press fit or any other method that will secure the plug136.

As shown inFIG.9, the oil orifice138allows oil (and refrigerant) to travel from the discharge chamber82to the ball bearing108along the path73(which may be referred to as the “nose bleed” path).

Bearing Oil Communication Hole

The electric compressor10may include one or more bearing oil communication holes. As discussed above, in the illustrated embodiment, a drive shaft90is rotated by the motor54to controllably actuate the compression device18. The drive shaft90has a first end90A and a second and90B. The housing10of the electric compressor10forms a first drive shaft supporting member22B and a second drive shaft support member24A. In the illustrated embodiment, the first drive shaft supporting member22B is formed in a motor side22of the inverter housing22A and the second drive shaft supporting member24A is formed within the center housing24. First and second ball bearings62,64are located within the first and second drive shaft support members22B,24A.

The location of the first drive shaft supporting members22B is not a flow-through area for refrigerant (and oil). This may result in a low lubricating condition and affect the durability of the electric compressor10.

As shown inFIG.16F, the first drive supporting member22B may include one or more holes22C to allow oil to enter the first drive support member22B and lubricate the first ball bearing62.

In the illustrated embodiment, the scroll-type electric compressor10includes a housing12, a first ball bearing62, a second ball bearing64, a refrigerant inlet port68, a refrigerant outlet port70, an inverter module44, a motor54, a drive shaft90, and a compression device18.

The housing12defines an intake volume74and a discharge volume82and includes first and second drive shaft supporting members22B,24A. The first ball bearing62is located within the first drive shaft supporting member22B. The first drive shaft support member22B of the housing12includes one or more oil communication holes22C for allowing oil to enter the first ball bearing62.

The second ball bearing64is located within the second drive shaft supporting member24A. The refrigerant inlet port68is coupled to the housing12and is configured to introduce the refrigerant to the intake volume74. The refrigerant outlet port70is coupled to the housing12and is configured to allow compressed refrigerant to exit the scroll-type electric compressor10from the discharge volume82. The inverter module144is mounted inside the housing12and is adapted to convert direct current electrical power to alternating current electrical power. The motor54is mounted inside the housing12. The drive shaft90is coupled to the motor54. The drive shaft90has a first end90A and a second end90B. The first end90A of the drive shaft90is positioned within the first bearing62and the second end90B of the drive shaft90is positioned within the second bearing64. The compression device18receives the refrigerant from the intake volume74and compresses the refrigerant as the drive shaft90is rotated by the motor54. As discussed above, in the illustrated embodiment, the first drive shaft support member22may be formed on the motor side22A of the inverter housing22.

The rotational movement within the motor section16of the compression device18creates a flow path and movement to the oil from the oil reservoir98, as shown by arrows88inFIG.9. As shown the oil flows from the oil reservoir98toward the motor section16and continues toward the stator58and rotor60. The rotational motion of the orbiting scroll, rotor and drive shaft pulls the oil upward to mix with the inlet flow of the refrigerant path72. The rotational movement of the rotor60and drive shaft90will further propel the oil against the motor side22A of the inverter housing22. The motor side22A surface further includes a series of ribs22D, shown inFIG.16F. The ribs22D provide the needed rigidity for supporting the first drive shaft support member22and allow for a ridged backing and pocket to secure the first bearing62. The inverter housing22may further defines an oil cavity (not shown) where the oil collected between the ribs22D is directed by gravity downward and into the oil. The ribs22D and the sloped surface of the motor side22A cooperate to capture and direct the oil splashed or propelled against the motor side22A by the rotor60or drive shaft90, to assist in increasing the oil flow into the oil cavity22E and first bearing62.FIG.16Fillustrates two communication holes22C, but it is appreciated additional or less than 2 oil communication hole22C may be included above and between the ribs22D on the motor side22A of the inverter housing22. For example in the illustrated embodiment the hole is 3.5 mm in diameter and the motor side22A includes a sloping wall between the ribs22D. In addition, the motor side22A may include a outer oil collection area22

Domed Inverter Cover

The scroll-type electric compressor10of the present invention may include a domed inverter cover20. The scroll-type electric compressor10includes the housing12, the refrigerant inlet port68, the refrigerant outlet port70, the inverter module44, the motor54, the drive shaft90, the compression device18and the inverter cover20. The housing12defines the intake volume70and the discharge volume82. The housing12has a generally cylindrical shape and the central axis90C. The refrigerant inlet port68is coupled to the housing12and is configured to introduce the refrigerant to the intake volume70. The refrigerant outlet port82is coupled to the housing12and is configured to allow compressed refrigerant to exit the scroll-type electric compressor10from the discharge volume82.

The inverter module44is mounted inside the housing12and adapted to convert direct current electrical power to alternating current electrical power. The motor54is mounted inside the housing12. The drive shaft90is coupled to the motor54. The compression device18is coupled to the drive shaft90and is configured to receive the refrigerant from the intake volume and to compress the refrigerant as the drive shaft90is rotated by the motor54.

As discussed above, the compression device18may rotate at a high speed (>2,000 RPM) which may create undesirable noise, vibration, and harshness (NVH) and low durability conditions. In the prior art, the inverter cover20is generally flat and tends to amplify and/or focus, the vibrations from the compression device18.

To disperse vibrations rather than focus, the vibrations from the compression device18, the inverter back cover20of the electric scroll-like compressor10of the fifth aspect of the disclosure is provided with a generally curved or domed profile.

As shown in the FIGS., specificallyFIGS.1,3and6, the inverter cover20is located at one end of the scroll-type electric compressor10and includes a first portion20A and a second portion20B. The first portion20A includes an apex or apex portion20C and is generally perpendicular to the central axis90C and has an apex20C and an outer perimeter20D. The first portion20A has a relatively domed-shaped such that the inverter cover20has a curved profile from the apex20C towards the outer perimeter20D. The amount and location of the curvature may be dictated or limited by other considerations, such as packaging constraints, i.e., the space in which the electric scroll-type compressor10must fit, and constraints placed by internal components, i.e., location and size). The first portion20A may also have to incorporate other features, e.g., apertures to receive fastening bolts. The second portion20B may include a portion of the inverter cover20that is not domed, i.e., is relatively flat that is located about the perimeter of the inverter cover.

Fixed Scroll Having Modified Scroll Flooring

In a first aspect of the present invention, the scroll-type electric compressor10with a modified fixed scroll flooring is configured to compress a refrigerant. The scroll-type electric compressor10includes the housing12, the refrigerant inlet port68, the refrigerant outlet port70, the inverter module44, the motor54, the drive shaft90, and the compression device18. The housing12defines an intake volume74and a discharge volume82.

The refrigerant inlet port68is coupled to the housing12and is configured to introduce the refrigerant to the intake volume74. The refrigerant outlet port70is coupled to the housing12and is configured to allow compressed refrigerant to exit the scroll-type electric compressor12from the discharge volume82. The inverter module144is mounted inside the housing12and adapted to convert direct current electrical power to alternating current electrical power. The motor54is mounted inside the housing12and the drive shaft90is coupled to the motor54.

In general, and as described above, the compression device18receives the refrigerant from the intake volume74and compresses the refrigerant as the drive shaft90is rotated by the motor54.

The compression device18includes a fixed scroll26and an orbiting scroll66. The compression device18defines antechamber volume134. The antechamber volume134(seeFIGS.18C and18G) feeds refrigerant to the chambers80at the start of a compression cycle. During the compression cycle, when the chambers80close (as the laps26B,66B come into contact, the pressure within the antechamber volume134drops due to suction which can affect the efficiency of the electric compressor10. In one aspect of the present invention, it is desirable to increase the volume of the antechamber (to make additional refrigerant available to the compression device18). This increases the “capacitance” of the compression device18and smooths out the compression cycle.

In the illustrated embodiment, the base26A,66A of one of the fixed scroll26and the orbiting scroll66has a cutout136to increase the antechamber volume134.

In the illustrated embodiment, the cutout136is located in the floor or base26A of the fixed scroll26.

As shown, the fixed scroll26has a first side26F defined by fixed scroll base26A and a second side26G defined by a top surface of the fixed scroll lap26B. The fixed scroll lap26B extends from the fixed scroll base26A towards the second side26G of the fixed scroll26. As shown inFIGS.18C and18G, the cutout136in the floor of the fixed scroll base26defines a first portion which has a depth, d1, which is greater than a depth, d2, of a second portion138.

The size of the first portion or cutout136may be limited by a couple constraints. First, the depth, d1, must leave sufficient material to maintain the structural integrity of the fixed scroll26. In addition, to ensure that the chamber80is sealed, the geometry of the cutout must remain outside the orbiting lap66B, to allow the chamber80to close and seal as shown in17D. The cutout136may be provide additional volume within the antechamber134to allow the volumes within chambers80in17D to be fully filled. The cutout136is limited by the path of the orbiting scroll66B, and limitations to the floor and wall thickness needed to the fixed scroll26. In addition, machine tooling and access to the floor of the fixed scroll may provide additional limitations to the size and areas outside the seal area of the orbiting scroll66B.

Isolation/Constraint System

In a second aspect of the present invention, an isolation and constraint system148may be used to isolate the housing12from the oscillations and pulsations caused by the orbiting scroll66.

In a typical, scroll-type electric compressor, the motor and the fixed scroll are directly coupled to the housing, is directly coupled to the housing. As discussed above, guidance pins directly coupled to the housing may cooperate with ring shaped slots on the orbiting scroll to limit articulation of the orbiting scroll as it orbits the drive shaft. With this type of arrangement, oscillations and pumping pulsations from the orbiting scroll may be transmitted to the housing and through the mounts to the, e.g., vehicle structure.

The scroll-type electric compressor10is configured to compress a refrigerant. The scroll-type electric compressor includes the housing12, the refrigerant inlet port68, the refrigerant outlet port70, the inverter module144, the motor54, the drive shaft90and a compression device18. The housing12defines an intake volume74and a discharge volume82and has a generally cylindrical shape. The refrigerant inlet port68is coupled to the housing12and is configured to introduce the refrigerant to the intake volume74. The refrigerant outlet port70is coupled to the housing12and is configured to allow compressed refrigerant to exit the scroll-type electric compressor12from the discharge volume82. The inverter module144is mounted inside the housing12and adapted to convert direct current electrical power to alternating current electrical power. The motor54is mounted inside the housing12. The drive shaft90is coupled to the motor54. The compression device18is coupled to the drive shaft90for receiving the refrigerant from the intake volume74and compressing the refrigerant as the drive shaft90is rotated by the motor54.

As discussed above, the compression device16includes a fixed scroll26and an orbiting scroll66. The fixed scroll26is located within, and is fixed relative to, the housing12. The orbiting scroll66is coupled to the drive shaft90. The orbiting scroll66and the fixed scroll26form compression chambers80for receiving the refrigerant from the intake volume74and for compressing the refrigerant as the drive shaft90is rotated about the center axis90C.

The orbiting scroll66has a lower surface having a plurality of ring-shaped slots66G (see above).

With specific reference toFIG.20A, the scroll-type electric compressor10further includes a thrust body150, the plurality of articulating guidance pins24B, a plurality of mounting pins152and a plurality of isolating sleeves154. The thrust body150has a plurality of guidance pin apertures152A. The plurality of articulating guidance pins24B extend from the guidance pin apertures152and extend towards the compression section18and into the ring-shaped slots66B. The guidance pins24B are configured to limit articulation of the orbiting scroll66as the orbiting scroll66orbits about the central axis90.

Each mounting pin152has a housing end152A and a thrust body end152B. The housing end152is press fit within respective receiving apertures in the housing12. The thrust body end152B is cylindrical with an outer surface. The plurality of isolating sleeves154are composed from a flexible material, such as a chemically resistant synthetic rubber. One such material is ethylene propylene diene monomer (EPDM). The thrust body end152of each mounting pin152is encapsulated within a respective sleeve154and is received in a respective slot150A within the thrust body150. In this way, the only connection between the thrust body150and the housing12is through the mounting pins152which is isolated or insulated by the sleeves154to prevent or minimize vibrations from the orbiting scroll66from being transmitted to the housing12.

As shown inFIG.20A, in one embodiment, the isolating sleeves152are integrally formed with a circular gasket or ring156.

As shown inFIG.20B, in another embodiment, the thrust body end152B of each mounting pin152is full encapsulated by the flexible material using, for example, an over-molding process. The outer surface of the of the isolating sleeves154may be rubbed to assist with the isolation.

Electric Compressor Head Design

In a third aspect of the electric compressor10of the disclosure, a front cover28design includes an oil separator96and a three-reed reed mechanism86. As discussed below, the design of the front cover28, the fixed scroll26and the reed mechanism86define a multicavity pulsation muffler system.

In prior art electric compressors, refrigerant is released from the compression device once per revolution (or orbit) of the orbiting scroll. This creates a first order pulsation within the compressed refrigerant released by the electric compressor. The relative strong amplitude and low frequency of the pulsation creating in the refrigerant may excite other components (internal or external to the electric compressor) which may create undesirable noise, vibration and harshness (NVH) and low durability conditions.

With reference toFIGS.18C-18FandFIGS.19A-19B, the multicavity pulsation muffler system160compressed refrigerant is released from the compression device18twice during a compression cycle. As discussed in more detail below, the compression device18includes two smaller secondary discharge ports are placed into (adjacent) two secondary discharge chambers, The secondary discharge chambers are downstream (in the discharge head) of the pressure drop from a central discharge port. As also described further below, the front cover28defines a parallel discharge path for refrigerant exiting the compression device18to the refrigerant outlet port70.

In the illustrated embodiment, the compressor10includes the housing12, the inverter module44, the motor54, and a compression device18. The housing12defines an intake volume74and a discharge volume82. The housing12has a generally cylindrical shape and a central axis90C. The inverter module44is mounted inside the housing12and adapted to convert direct current electrical power to alternating current electrical power. The motor54is mounted inside the housing.

The compression device18is coupled to the motor54for receiving the refrigerant from the intake volume74and compressing the refrigerant as the motor54is rotated.

The compression device18has a central compression device outlet orifice84A and first and second side compression device outlet orifices84B for controllably releasing compressed refrigerant into the discharge volume82during a compression cycle. The compression device18is configured to release compressed refrigerant into the discharge volume82via the first and second side compression device outlet orifices84B earlier in the compression cycle than refrigerant is released via the central discharge orifices84A.

In addition, the oil separator96utilizes two parallel paths between the compression device18and the refrigerant outlet port70to reduce the net pressure drop while maintaining the reduction in this pulsation.

In the illustrated embodiment, the oil separator96may be located in the discharge volume82and integrally formed with the discharge head or front cover28. As discussed above, oil is used to provide lubrication between the moving components of the electric compressor10. During operation, the oil and the refrigerant become mixed. The oil separator96is necessary to separate the intermixed oil and refrigerant before the refrigerant leaves the electric compressor10.

Generally, refrigerant is released from the compression device18during each cycle, i.e., revolution (or orbit) of the orbiting scroll66. In the illustrated embodiment, refrigerant leaves the compression device18through the central orifice84A and two side orifices84B in the fixed scroll26. Release of the refrigerant through the orifices,84A,84B is controlled by the central reed87A and two side reeds87B, respectively (see below).

In the illustrated embodiment, the oil separator96connects the discharge chambers (see below) by relatively small channels to create pressure drops between the chambers. This acts to smooth out the flow of compressed refrigerant out of the electric compressor10. Additionally, the oil separator96utilizes two parallel paths between the compression device18and the refrigerant outlet port70to reduce the net pressure drop while maintaining the reduction in this pulsation.

The oil separator96may include a series of partitions98A extending from an inner surface of the front cover28. As shown, the walls98A separate the discharge volume82into a central discharge chamber82A, two side discharge chambers82B, am upper discharge chamber82C and the oil reservoir98. The central discharge chamber82A is adjacent the central reed87A and receives intermixed pressurized refrigerant and oil from the compression device18through the central orifice84via the reed87A. The side discharge chamber82B are adjacent respective side reed87B and receives intermixed pressurized refrigerant and oil from the compression device18through the side orifices84B via respective reeds87B. Generally, the pressure of the refrigerant in the chambers is: central discharge chamber82A>side discharge chambers82B>upper discharge chamber82C.

The central discharge chamber82A is in fluid communication with the two side discharge chambers82B via respective side channels100which are in fluid communication with the upper discharge chamber82C and the oil reservoir98via upper discharge channels102and lower discharge channels104, respectively. In one embodiment, the side channels100extend at an acute angle through to the side discharge chambers82B. The angle of the channels100further directs the impact of the discharging mixture of refrigerant and oil to further improve the separation and increase the amount of oil separated out by the oil separator96. For example, inFIG.19C, the side channels100extend through and downward into the side discharge chambers82B at approximately a 45-degree angle relative to the inner wall of the central discharge chamber82A. However, the angle may vary depending on the application or surface contours of the side discharge chambers82C, and in some variations may increase to approximately 60 degrees. The angle may vary but is designed to direct the flow to create turbulence and direct the flow impact to create a tortuous path within the side discharge chambers82C to increase the separation of oil into the lower discharge channels104.

As shown, the oil separator96includes the central discharge chamber82A and a lower baffle132. In the illustrated embodiment, the lower baffle132is chevron-shaped (inverted “v”) and is located between the central chamber82and the oil reservoir98. The shape of the lower baffle132creates an area of low pressure directly underneath. Intermixed oil and refrigerant enter the central discharge chamber82A and is drawn downward by the low-pressure area. The oil and refrigerant are separated when the intermixed oil and refrigerant comes into contact with the upper surface of the lower baffle132. The oil drops into the oil reservoir98.

Refrigerant may enter the side discharge chambers82B via the side channels100and/or lower discharge channels104. Refrigerant may then enter the upper discharge chamber82B and then exit via the refrigerant outlet port70.

The oil reservoir98is located below the pair of side chambers and is connected thereto via the respective lower discharge channels104. The oil reservoir is configured to receive oil separated from the compressed refrigerant in the side chambers. Gravity acting on the oil assists in the separation and the oil falls through the lower discharge channels104located in the side discharge chambers82B into the oil reservoir98.

As discussed above, the reed mechanism86includes a discharge reed86A and a reed retainer86B which define the reeds87A,87B. The discharge reed86A is used to tune the pressure at which the refrigerant is allowed to exit the compression device18through the central orifice84A and two side orifices84B, respectively.

Assembly and Electric Compressor with Non-Radial Clamping Feature

In another aspect of the present invention, the electric compressor10includes a cylindrical sleeve170configured to constrain the motor section16within the outer housing12. As discussed in more detail below, the cylindrical sleeve170has a tubular side wall172and a top cover174defining an interior cavity176. The interior cavity176has an open end178. The cylindrical sleeve170is configured to receive the motor section16or motor54, together create a singular module assembly210.

The tubular side wall172and the top cover174may be composed from aluminum. In embodiment, the tubular side wall172and the top cover174are one piece. For example. The cylindrical sleeve170may be cast as a single piece and then machined. Alternatively, the tubular side wall172and the top cover174are separate pieces and then fastened together by any suitable methods, such as welding or using clamps or other means.

In a first embodiment of the present invention, the electric compressor10is configured to compress a refrigerant. The electric compressor10includes the housing or outer housing12, the refrigerant inlet port68, the refrigerant outlet port70, the inverter module44, the motor54, the drive shaft90, the cylindrical sleeve170, and a compression device18. The housing12defines an intake volume74and a discharge volume82and has a generally cylindrical shape and a central axis90C.

The refrigerant inlet port68is coupled to the housing12and configured to introduce the refrigerant to the intake volume74. The refrigerant outlet port70is coupled to the housing12and is configured to allow compressed refrigerant to exit the electric compressor10from the discharge volume82. The inverter module44is mounted inside the housing12and is adapted to convert direct current electrical power to alternating current electrical power. The motor54is mounted inside the housing12. The drive shaft90is coupled to the motor54.

The cylindrical sleeve170has a tubular side wall172and a top cover174defining an interior cavity176. The interior cavity176has an open end178. The cylindrical sleeve170is configured to receive the motor54therein and constrain the motor54within the interior cavity176.

The compression device18is coupled to the drive shaft90and receives the refrigerant from the intake volume and compresses the refrigerant as the drive shaft90is rotated by the motor54. The clamping mechanisms170are discussed in further detail below.

In a second embodiment of the present invention, an assembly210includes a housing12, a motor54, a drive shaft90, and a cylindrical sleeve170. The housing12has a generally cylindrical shape and has a central axis90C. The motor54is mounted inside the housing12. The drive shaft90is coupled to the motor54. The cylindrical sleeve170has a tubular side wall172and a top cover174defining an interior cavity176. The interior cavity176has an open end178. The cylindrical sleeve170is configured to receive the motor54therein and constrain the motor54within the interior cavity176. As discussed in further detail below, the module assembly of the cylindrical sleeve170, with the housing12, allow for ease of aligning the concentricity of the sleeve170, stator58, and circular drive shaft supporting member218, relative to the housing12, with a rotational location for alignment with the mating components simplified by rotational orientation being determined by a rotational feature194(see below).

In a third embodiment of the present invention, an electric compressor10having a central axis90C and being configured to compress a refrigerant, is provided. The compressor10includes the housing12, the refrigerant inlet port68, the refrigerant outlet port70, the inverter section14, the motor section16, the compression device18and the cylindrical sleeve170.

The housing12defines an intake volume74and a discharge volume82. The refrigerant inlet port68is coupled to the housing12and is configured to introduce the refrigerant to the intake volume74. The refrigerant outlet port70is coupled to the housing12and is configured to allow compressed refrigerant to exit the electric compressor12from the discharge volume82.

The inverter section14includes an inverter housing22, an inverter back cover20, and an inverter module44. The inverter back cover20is connected to the inverter housing22and forms an inverter cavity30. The inverter module44is mounted inside the inverter cavity30and is adapted to convert direct current electrical power to alternating current electrical power.

The motor section16includes the drive shaft90and the motor54. The drive shaft90is located within the housing12. The motor54is located within the housing12to controllably rotate the drive shaft90.

The compression device18is coupled to the drive shaft90for receiving the refrigerant from the intake volume74and for compressing the refrigerant as the drive shaft90is rotated by the motor54. The compression device18includes a fixed scroll26and an orbiting scroll66. The fixed scroll26is located within, and being fixed relative to, the housing12. The orbiting scroll66is coupled to the drive shaft90. The orbiting scroll66and the fixed scroll26form compression chambers58for receiving the refrigerant from the intake volume74and for compressing the refrigerant as the drive shaft90is rotated. The cylindrical sleeve170has a tubular side wall172and a top cover174defining an interior cavity176. The interior cavity176has an open end178. The cylindrical sleeve170is configured to receive the motor section16therein and constrain the motor54within the interior cavity176.

With specific reference toFIGS.22A-22K, a first illustrated embodiment of the cylindrical sleeve170is shown. The cylindrical sleeve170includes a tubular side wall172and a top cover174forming an interior cavity176and an open end178. The cylindrical sleeve170encloses the motor section16or motor54. The cylindrical sleeve170constrains the motor54therein. As will be disclosed in further detail below, the cylindrical sleeve170is constrained within the housing22of the electric compressor10.

In the illustrated embodiment, the motor54includes a stator58having an outer diameter180. The interior cavity176of the cylindrical sleeve170has an inner diameter182. The outer diameter180of the stator58and the inner diameter176of the cylindrical sleeve170are configured to establish an interference fit therebetween. In one embodiment the interference between the outer diameter180of the stator58and the inner diameter176cylindrical sleeve170may be between 100 and 300 microns. In one embodiment, the interference may be approximately 200 microns.

In the first illustrated embodiment, the cylindrical sleeve170has an outer diameter184. As discussed above, the housing12defines a motor cavity56with an inner diameter186. A slip fit between the outer diameter184of the cylindrical sleeve170and the inner diameter186of the motor cavity56maintains a concentric relationship between the cylindrical sleeve170and motor/motor section54/16. The slip fit between the outer diameter184of the cylindrical sleeve170and the inner diameter186of the motor cavity56is established by an interference therebetween (see below). The slip fit between the outer diameter184of the cylindrical sleeve170and the inner diameter186of the motor cavity56may be either a tight slip fit or a loose interference fit. The tight slip fit relationship or a loose interference fit reduces the chances of causing an out of round or distortion to the housing12, this is further described in related application Ser. No. 18/147.913 filed on same day as the present application (see above) and incorporated by reference herein.

The rotational feature194may be provided to allow the cylindrical sleeve170and motor54or motor section16to be positioned correctly within the housing12. In the illustrated embodiment, the rotational feature194includes at least one tab196extending from an outer surface of the cylindrical sleeve170. The at least one tab196fits within a corresponding slot198on an interior surface of the housing12.

In one embodiment, the slot198is configured to receive the at least one tab196to position the cylindrical sleeve170and motor54or motor section16to be positioned correctly within the housing12. The slot198may be machined within the housing12to provide a tight or press-fit relationship between the at least one tab196and the corresponding slot198.

In another embodiment, the rotational feature194may include a pin214and the at least one tab198may include an aperture216for receiving the pin214for more accurate positioning of the cylindrical sleeve170and motor54or motor section16within the housing12. The pin214may be cast and/or machined unitarily with the housing12or may be a separate component and press fit through an aperture of the tab196and secured within an aperture located at the bottom of the slot198within the housing12.

As discussed above, the housing12defines a cavity or inverter cavity30. An inverter circuit46is located within the inverter cavity30and provides power to the motor54to control the rotational speed and direction of the motor54and the electric compressor10via a plurality of power terminals188. In the illustrated embodiment, the power terminals188extend from the motor cavity56to the circuit cavity30through apertures190in the top cover174. Grommets or o-rings192may provide sealing around the power terminals188.

The rotational feature194assists in maintaining concentricity and/or positioning of elements of the compressor10within the housing12by correctly positioning the motor54or motor section16within the sleeve170and the sleeve170within the housing12. Generally, the motor section16or motor54is assembly and inserted within the cylindrical sleeve170. During the assembly process, the cylindrical sleeve170may be heated before the motor section16or motor54is inserted therein. The cylindrical sleeve170may then be cooled or allowed to cool to create a tight fit between the cylindrical sleeve170and the motor section16or motor54.

The pin214provides for easier assembly and rotational relationship between the motor section16within the housing12. In addition, the rotational feature194allows for the cylindrical sleeve170to maintain concentricity within the motor54and locate and align the mating components of the compressor10. For example, the cylindrical sleeve170creates a module that allows for concentrical alignments between the sleeve170, power terminals188, and concentric alignment of the stator60to the circular drive shaft supporting member218for positioning the ball bearing62without distortion being created by the commonly used press-fit or shrink fit of the prior art by securing of the stator60directly into the housing12, or additional locating steps as the compressor is being assembled. The concentric relationship is simplified by the module, and this further improves the NVH aspects of the compressor10or any out of axis rotational misalignments that may be created by the distortions, or assembly misalignments between the motor54, to the drive shaft90and the rotational motion within the compression device18.

If the tubular side wall172and the top cover174of the cylindrical sleeve170are integral, then the first bearing62is positioned within the circular drive shaft supporting member218or assembled with the cylindrical sleeve170and motor section16or motor54. Otherwise, the top cover174may be a separate component with the first bearing62being secured first within circular drive shaft supporting member218, and the top cover174are assembled thereafter, and the motor section16secured into the cylindrical sleeve170, create the integrated module assembly210, that is then as a single unit mated to and secured within the inner diameter186of the motor cavity56.

The first bearing62within the circular drive shaft supporting member218, combined and concentrically aligned with the cylindrical sleeve170and the motor section16or motor54may then be placed in the housing12and positioned at the correct orientation using the rotational feature194. This arrangement ensures that all components are positioned for alignment within the housing and concentrically located within the housing12and correctly aligned for mating the other components of the compressor10.

Additionally, this ensures that the location of the power terminals188are positioned correctly relative to the housing12so that the inverter section14and inverter back cover20may be more easily positioned thereon and fastened using the fasteners32,34.

Additionally, the cylindrical sleeve170may include a slot or channel212located around a periphery of the cylindrical sleeve170. The slot212may be configured to receive an o-ring (not shown) to hermetically seal the circuit cavity30from the motor cavity56(to keep refrigerant from entering the circuit cavity30. And in one illustrated embodiment,FIGS.22B and22C, the o-ring may be axially located between the windows200,202and the top cover174to further provide an additional seal refrigerant and lubricant from the power terminals188. This additional seal may further reduce current loss or creep. The o-ring seal allows the upper surface of the top cover174between the inverter housing22when mated to remain refrigerant free to avoid any contact or current loses with creep of current into the refrigerant. However, this sealing may also create additional challenges since the inverter circuits46creates heat, and a flow or heat sink may be required to be in contact with the refrigerant to dissipate such heat. Alternatively, additional refrigerant flow may have to be directed through the windows200,202in this embodiment.

The tubular side wall172of the cylindrical sleeve170may also include at least one window200configured to allow an encapsulation material to be applied to an interior of the motor54. For example, encapsulation material may need to be deposited to cover and isolate the junction between the power terminals188of the motor54and the electrical leads supplying power to the motor54from the power circuit46. The encapsulation material further reduces any current losses from the stator and junction into the refrigerant and lubrication circulating through the compressor10.

In addition, the tubular side wall172of the cylindrical sleeve170may include a refrigerant inlet window202to allow refrigerant to enter the intake volume74. As shown inFIG.23A, the inlet window206reduces the flow restrictions to the refrigerant entering into the compressor10and allow for additional flow of refrigerant to flow through the inverter electronics46and increase flow through the stator and rotor area of the drive motor. This may be advantageous for higher demand applications. Also, this arrangement with the inlet windows206may allow for the slot212for the o-ring to be positioned to function more as a noise and vibration damper at any location along the length of the sleeve170.

As discussed above, the motor54has an end located adjacent the open end178of the cylindrical sleeve170. The lower end of the cylindrical sleeve170has a lower concentric locating feature204configured to be received within a motor receiving portion of the housing12to assist in maintaining the motor and stator are concentric within the housing12. An upper concentric locating feature208located at an upper end of the cylindrical sleeve170assists in maintaining the concentricity of the motor54within the housing12, as well as the positioning of the bearing62within the electric compressor10. The concentric locating features204,208also help increase the isolation between the motor54and the housing12, thereby improving noise, vibration, and harshness (NVH) characteristics of the electric compressor10. In one embodiment, the concentric locating features204,208maintenance an interference fit between with the housing12. For example, in a specific embodiment, the interference between the outer diameter184of the cylindrical sleeve170at the concentric locating features204,208and the inner diameter186of the motor cavity56may be between 40 and 100 microns. The relationship between the motor cavity56and the outer diameter184of the cylindrical sleeve170outside the locating features204,208may be defined by a slip fit or very light or small negative interference fit. The concentric locating features204,208and the slot or channel212may be machined in the sleeve170, and the length of the cylindrical sleeve170may then not impart a radial force and thereby reducing or eliminating the prior art issue with radial distortion.

With reference toFIG.22K, a bottom surface of the top cover174of the cylindrical sleeve170may include a circular drive shaft supporting member218for receiving the ball bearing62associated with one end of the drive shaft90A of the motor54.

With specific reference toFIGS.23A-22I, a second illustrated embodiment of the cylindrical sleeve170is shown (so like elements are numbered in a similar manner). With specific reference toFIGS.23H-23I, the top cover174may include at least one aperture206configured to allow refrigerant to flow into the inverter cavity56to provide cooling to the circuit46. Although not required to prevent refrigerant from entering the inventor cavity56, the slot or channel212and o-ring may be provided in the second illustrated embodiment to improve the NVH characteristics of the compressor10. As discussed above, the slot212may be placed at a location outside the locating feature204,208.

The foregoing invention has been described in accordance with the relevant legal standards, thus the description is exemplary rather than limiting in nature. Variations and modifications to the disclosed embodiment may become apparent to those skilled in the art and fall within the scope of the invention.