Scroll compressor with Oldham ring and keys in orbiting scroll

A scroll compressor includes a fixed scroll, an orbiting scroll, a rotating shaft, an Oldham ring, and a plurality of first keys. The orbiting scroll is configured to engage the fixed scroll. The rotating shaft is eccentrically coupled to the orbiting scroll and configured to operate the orbiting scroll. The Oldham ring has a ring body that defines a plurality of slots. The plurality of first keys are coupled to the orbiting scroll and inserted to the plurality of slots, respectively. The plurality of first keys are configured to slide at the plurality of slots in a radial direction and include a material different from a material of the Oldham ring.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Stage application under 35 U.S.C. § 371 of International Application No. PCT/KR2021/008607, filed on Jul. 6, 2021, which claims the benefit of Korean Application No. 10-2020-0186345, filed on Dec. 29, 2020. The disclosures of the prior applications are incorporated by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates to a scroll compressor having an Oldham ring for preventing rotation of an orbiting scroll.

BACKGROUND

A scroll compressor is a device for compressing refrigerant by having a motor part and a compression part accommodated in a sealed accommodation space. The motor part is connected to the compression part by a rotating shaft, to transmit rotational force to the compression part through the rotating shaft.

The compression part includes a fixed scroll and an orbiting scroll. The orbiting scroll performs an orbiting motion relative to the fixed scroll by the rotational force transmitted from the motor part. The fixed scroll and the orbiting scroll form a compression chamber having a suction chamber, an intermediate pressure chamber, and a discharge chamber. The refrigerant is suctioned into the compression chamber, compressed, and then discharged.

The scroll compressor has an anti-rotation mechanism for preventing the rotation of the orbiting scroll.

An Oldham ring (also called “Oldham's Coupling”) or a pin-and-ring type may be applied as the anti-rotation mechanism.

The pin-and-ring type anti-rotation mechanism may be advantageous compared to the Oldham ring type in terms of improving reliability by improved durability and reducing a weight of the compressor by a reduced weight.

However, the pin-and-ring type is relatively disadvantageous in terms of an assembling property because a plurality of pins and rings must be respectively installed on the orbiting scroll and a member in contact with the orbiting scroll.

For this reason, research to replace the pins and rings by improving a material of Oldham Ring is undergoing.

In particular, the scroll compressor can improve motor efficiency by making the Oldham ring using an aluminum material to reduce a weight of the Oldham ring.

On the other hand, in consideration of the improvement of the motor efficiency, it is advantageous to manufacture the orbiting scroll and the main frame, in addition to the Oldham ring, by using the aluminum.

However, when the orbiting scroll and the main frame are also made of the aluminum, friction surfaces relative to the Oldham ring are also made of the same aluminum, which drastically deteriorates friction characteristics.

Recently, techniques for improving a wear problem caused by friction between the Oldham ring and components relative to the Oldham ring have been introduced.

In order to solve the deterioration of the friction characteristics that is caused when the Oldham ring is made of the same type of material as the aluminum forming the orbiting scroll, it may be considered to change the material of the Oldham Ring to an iron-based material.

However, if the entire Oldham ring is made of the iron-based material, the weight of the Oldham ring increases and this causes an increase in vibration and noise due to a reciprocating motion of the Oldham ring during a high-speed operation. This also increases a material cost of the Oldham ring itself.

In order to solve the above problems, some related art discloses a compressor having a self-assembly Oldham ring.

Such a compressor discloses a technology capable of increasing wear resistance while lightening a weight of the Oldham ring by press-fitting or bonding a key part made of a different material from a ring part of the Oldham ring to the ring part.

However, this compressor has the following problems.

First, in order to press-fit the key part to the ring part, a fixing protrusion for fixing the key part should be formed to protrude from one side surface of the ring part in an axial direction. However, since a cross-sectional area of the fixing protrusion to be coupled to the key part decreases, supporting strength of the ring part for the key part may be weakened. This may lower mechanical reliability for the Oldham ring.

Second, when assembling the ring part and the key part, there may be a clearance in a coupled portion due to a machining error or an assembly error. In this case, the orbiting scroll may be pushed in a circumferential direction as the key part gets twisted with respect to the ring part when the compressor is driven. This may cause a separation between a fixed wrap and an orbiting wrap, thereby increasing compression loss. The clearance of the key part may be prevented by applying an adhesive between the key part and the fixing protrusion, but the addition of the adhesive applying process increases the number of processes.

Third, the key part may be separated from the ring part or rotates in the ring part in vain due to a difference of a thermal expansion coefficient between the ring part and the key part.

Some related art discloses a technology that an Oldham ring is made of aluminum but only a key part of the Oldham ring that substantially rubs against a main frame and an orbiting scroll is made of an iron-based material (or a material different from the material of the Oldham ring), such that the key part of the Oldham ring is press-fitted or bonded to a fixing protrusion integrally formed with a ring part of the Oldham ring.

However, this technology has the following problems.

First, when it is failed to secure a thickness of the fixing protrusion to which the key part is press-fitted, the fixing protrusion may be damaged.

Second, when the fixing protrusion does not have a sufficient height, it has a small press-fitting or bonding area, which causes the key part to be separated from the fixing protrusion.

Third, a coating layer that is made of a lubricating material or the like may also be formed on a surface of the Oldham ring. However, the formation of the separate coating layer may increase a fabricating cost and also the coating layer may come off or be worn due to a long-term use, thereby causing damage or increased friction loss of the Oldham ring.

Other related art discloses a scroll compressor.

In this related art, a wear-resistant member is disposed between a key groove of an orbiting scroll and a key part of an Oldham ring, to prevent a direct contact between the orbiting scroll and the Oldham ring. In addition, deterioration of frictional characteristics due to friction between the same types of materials can be prevented while the Oldham ring is formed of the same type of material as a material forming the orbiting scroll.

However, since the wear-resistant member of this scroll compressor is a steel plate with a thin thickness, it is advantageous in terms of machinability, but the thin thickness may lower rigidity of the wear-resistant member which may cause deformation of the wear-resistant member when it is press-fitted to the key groove.

In addition, if a surface of the wear-resistant member is not formed evenly during machining of the wear-resistant member, an assembly property of the wear-resistant member may be deteriorated.

Even if the wear-resistant member is coupled to the key groove, the deformation of the wear-resistant member may cause a problem that the key part of the Oldham ring is caught in the wear-resistant member during sliding along the wear-resistant member.

Other related art discloses a scroll compressor.

Such other related art discloses a technology for reducing wear of a key part of the Oldham ring and a key groove in which the key part slides.

Such other related art includes a liner formed in a U-like shape on the key groove and the liner is formed of a material different from a base material of the key groove, which can prevent wear of the key part and the key groove.

However, this scroll compressor discloses a structure for preventing the liner from being radially separated from the key groove, but does not disclose a structure for preventing the liner from being axially separated from the key groove.

Due to this, the liner of this scroll compressor may be separated from the key groove in the axial direction.

SUMMARY

A first aspect of the present disclosure is to provide a scroll compressor capable of improving motor efficiency by reducing a weight of an Oldham ring while applying the Oldham ring as an anti-rotation mechanism.

A second aspect of the present disclosure is to provide a scroll compressor capable of forming an Oldham ring using the same type of material as a material of a frame or orbiting scroll, to which the Oldham ring is coupled, or a fixed scroll.

A third aspect of the present disclosure is to provide a scroll compressor capable of enhancing reliability by securing support strength of an Oldham ring key.

A fourth aspect of the present disclosure is to provide a scroll compressor capable of enhancing efficiency of the compressor by simplifying a structure of a first key and a slot accommodating the first key and suppressing a generation of a clearance that is an allowable value or greater.

A fifth aspect of the present disclosure is to provide a scroll compressor capable of preventing an Oldham ring key from being separated from or rotating in vain in a key coupling portion due to a difference in thermal expansion.

A sixth aspect of the present disclosure is to facilitate machining a key hole, in which an Oldham ring key is accommodated, and to improve precision.

A seventh aspect of the present disclosure is to provide a scroll compressor capable of constantly maintaining frictional area and surface pressure of an Oldham ring key by preventing the Oldham ring key from being exposed to outside of a key hole while an orbiting scroll pivots.

An eighth aspect of the present disclosure is to provide a scroll compressor capable of using an existing shape of an Oldham ring as it is when a key receiving portion of the Oldham ring is press-fitted to an orbiting end plate of an orbiting scroll.

In order to achieve the first object described above, there is provided a scroll compressor that may include: a fixed scroll; an orbiting scroll engaged with the fixed scroll; a rotating shaft eccentrically coupled to the orbiting scroll and configured to operate the orbiting scroll; an Oldham ring having a ring body in an annular shape and a plurality of slots formed in the ring body; and a plurality of first keys disposed on the orbiting scroll, slidably received in the plurality of slots in a radial direction, respectively, and formed of a material different from that of the Oldham ring.

With the configuration, the Oldham ring can be decreased in weight so as to improve motor efficiency, thereby improving friction characteristics.

In one embodiment, each of the first keys may protrude from one axial side surface of the orbiting scroll to an inside of the slot, and the slot may extend from the ring body in a radial direction and may be formed through the ring body in a thickness direction of the ring body.

With the configuration, the first key can slide along the slot in the radial direction of the ring body, such that the orbiting scroll can perform an orbiting motion relative to the fixed scroll. This can prevent rotation of the orbiting scroll.

In one embodiment, the orbiting scroll and the Oldham ring may be made of the same material.

The orbiting scroll and the Oldham ring may be formed of an aluminum material, and the first key may be formed of an iron-based material.

In another embodiment, the first keys may be made of a porous material.

With this configuration, it can be advantageous in terms of lubrication of the compressor.

In one embodiment, each of the first keys may protrude from one axial side surface of the orbiting scroll to an inside of the slot, and the slot may extend in the radial direction of the ring body, and may have one side open toward the first key and an opposite side shielded by a shielding portion.

This can reinforce rigidity of a surrounding portion of the slot, and oil can be stored inside the slot.

In order to achieve the third and fourth aspects of the present disclosure, the first key may have a rectangular cross-sectional shape, a radial length of the slot may be longer than a radial length of the first key, and a widthwise side surface of the slot may be slidably brought into contact with a side surface of the first key facing the same.

With the configuration, the first key can secure a thickness, so as to reinforce rigidity thereof.

In one embodiment, a fixing groove may be formed to be recessed in one axial side surface of the orbiting scroll, and the first key may be press-fitted into the fixing groove.

This can secure a height for fixing the first key.

In order to achieve the fifth aspect of the present disclosure, the orbiting scroll may include an orbiting scroll end plate formed in a disk shape and supporting an orbiting wrap engaged with the fixed scroll, a plurality of fixing grooves formed in one axial side surface of the orbiting scroll end plate, a plurality of first fastening holes respectively formed toward the fixing grooves through another axial side surface of the orbiting scroll end plate, and a plurality of fastening members disposed to fasten the first keys, coupled to the fixing grooves through the plurality of first fastening holes, to the orbiting scroll.

With the configuration, the first key received in the fixing groove can be prevented from rotating in vain.

In another embodiment to achieve the fifth aspect described above, the orbiting scroll may further include an orbiting scroll end plate supporting the orbiting wrap engaged with the fixed scroll, a plurality of fixing grooves formed in one axial side surface of the orbiting scroll end plate facing an opposite side to the fixed scroll, a plurality of fastening grooves respectively recessed in a radial outer surface of the orbiting scroll end plate part in a direction crossing the fixing grooves, second fastening holes formed to radially overlap the fastening grooves such that the first keys are inserted therethrough, and press-fit pins fastened through the second coupling holes via the fastening grooves, such that the first keys coupled to the fixing grooves are fastened to the orbiting scroll.

With the configuration, the first key received in the fixing groove can be prevented from rotating in vain.

In order to achieve the sixth and seventh aspects described above, the Oldham ring may include protrusions protruding radially from at least one of an outer circumferential surface and an inner circumferential surface of the ring body, and the slots may be formed in the protrusions, respectively.

According to this configuration, a size of the slot can be secured.

In one embodiment of the present disclosure, the scroll compressor may further include a casing, and a frame fixed to an inside of the casing together with the fixed scroll and rotatably supporting the rotating shaft. The Oldham ring may be disposed between the orbiting scroll and the frame. The Oldham ring may include a plurality of second keys protruding from one axial side surface of the ring body toward the frame and slidably received in a plurality of key grooves formed in the frame.

According to this configuration, the rotation of the orbiting scroll can be prevented.

According to another embodiment of the present disclosure, a scroll compressor may include: a casing; a fixed scroll having a fixed wrap and fixed to an inside of the casing; an orbiting scroll having an orbiting wrap engaged with the fixed wrap to define a compression chamber together with the fixed scroll; a rotating shaft eccentrically coupled to the orbiting scroll and configured to operate the orbiting scroll; a frame fixed inside the casing together with the fixed scroll and rotatably supporting the rotating shaft; an Oldham ring having a ring body, and a plurality of first slots and a plurality of second slots alternately disposed on the ring body to be spaced apart from each other with a phase difference of 90 degrees in a circumferential direction; a plurality of first keys disposed on the orbiting scroll, slidably received in the plurality of first slots, respectively, and formed of a material different from a material of the Oldham ring; and a plurality of second keys disposed on the frame, slidably received in the plurality of second slots, respectively, and formed of a material different from a material of the frame.

With the configuration, the Oldham ring can be decreased in weight so as to improve motor efficiency, thereby improving friction characteristics.

In order to achieve the second aspect described above, the Oldham ring may be disposed between the orbiting scroll and the frame. The orbiting scroll, the frame, and the Oldham ring may be formed of the same material that is an aluminum material. The first keys may be disposed between the orbiting scroll and the Oldham ring to frictionally contact the first slots. The second keys may be disposed between the frame and the Oldham ring to frictionally contact the second slots. The first keys and the second keys may be formed of an iron-based material that is different from the material of the Oldham ring.

In order to achieve the eighth aspect described above, a scroll compressor according to one embodiment may include: a fixed scroll; an orbiting scroll engaged with the fixed scroll; a rotating shaft eccentrically coupled to the orbiting scroll and configured to operate the orbiting scroll; an Oldham ring having a ring body, and a plurality of first keys formed on the ring body; and a plurality of first key groove forming parts disposed in the orbiting scroll, each having a first key groove in which the first key is slidably received, and formed of a material different from a material of the Oldham ring and the orbiting scroll; and separation prevention members each configured to prevent the first key groove forming part from being separated from the orbiting scroll. The plurality of first key groove forming parts may be coupled to first key groove mounting parts recessed in one axial side surface of the orbiting scroll that faces an opposite side to the fixed scroll. Each of the first key groove forming parts may include a plurality of side wall plates, an inner plate formed in a curved shape to connect one radial side of each of the plurality of side wall plates, and a horizontal plate formed in a planar shape to connect one axial side surface of each of the plurality of side wall plates.

According to this configuration, the separation prevention member can prevent the first key groove forming part from being separated from the orbiting scroll in the radial and axial directions.

In one embodiment of the present disclosure, the separation prevention member may include a fastening member inserted through the horizontal plate to be fastened to the first key groove mounting part.

A scroll compressor according to one embodiment of the present disclosure may include: a fixed scroll; an orbiting scroll engaged with the fixed scroll; a rotating shaft eccentrically coupled to the orbiting scroll and configured to operate the orbiting scroll; an Oldham ring having a ring body, and a plurality of first keys formed on the ring body; a plurality of first key groove forming parts disposed in the orbiting scroll, each having a first key groove in which the first key is slidably received, and formed of a material different from a material of the Oldham ring and the orbiting scroll; and separation prevention parts each configured to prevent the first key groove forming part from being separated from the orbiting scroll. Each of the first key groove forming parts may include a plurality of side wall plates, and an inner plate connecting one radial side of each of the plurality of side wall plates. The separation prevention part may include protrusions disposed on outer surfaces of the side wall plates to be inserted into protrusion receiving grooves that are formed in inner walls of the first key groove forming part.

A scroll compressor according to another embodiment related to the present disclosure may include: a fixed scroll; an orbiting scroll engaged with the fixed scroll; a rotating shaft eccentrically coupled to the orbiting scroll and configured to operate the orbiting scroll; an Oldham ring having a ring body, and a plurality of first keys formed on the ring body; a plurality of first key groove forming parts disposed in the orbiting scroll, each having a first key groove in which the first key is slidably received, and formed of a material different from a material of the Oldham ring and the orbiting scroll; and separation prevention parts each configured to prevent the first key groove forming part from being separated from the orbiting scroll. Each of the first key groove forming parts may include a plurality of side wall plates, and an inner plate connecting one radial side of each of the plurality of side wall plates. The separation prevention part may include a fixing protrusion protruding radially from an outer surface of the inner plate to be fixedly inserted into a protrusion fixing groove formed in the orbiting scroll.

According to this configuration, the rotation of the orbiting scroll can be prevented.

According to embodiments of the present disclosure, the following effects can be obtained.

First, an Oldham ring can be made of an aluminum material that is the same material as that of an orbiting scroll, so as to be decreased in weight, thereby improving motor efficiency.

Second, a first key protrudes from a lower surface of the orbiting scroll toward the Oldham ring. The first key can be received in a slot formed in the Oldham ring, so as to be slidable along the slot. The first key is formed of an iron-based material that is different from that of the orbiting scroll.

With this configuration, even if the Oldham ring is made of the same material as the orbiting scroll, only the first key of the orbiting scroll that rubs against the slot of the Oldham ring is formed of the iron-based material that is different from the material of the orbiting scroll, thereby improving friction/wear characteristics.

Third, instead of a structure in which a first key covers at least one side surface of a fixing protrusion protruding from one axial side surface of an Oldham ring, an integrated structure in which the first key protrudes from a second end plate of the orbiting scroll to be received in the slot of the Oldham ring can be employed. This can reinforce support stiffness and rigidity of the first key110without reducing a thickness of the first key110.

In addition, a transverse or longitudinal length of the first key may be the same as or similar to a width of the slot.

Fourth, since the first key does not have the structure in which the first key is coupled to a fixing protrusion protruding from one axial side surface of the Oldham ring, a generation of clearance due to a machining error and an assembly error between the fixing protrusion and the first key of the Oldham ring can be prevented.

Fifth, the first key is press-fitted to a fixing groove formed in the second end plate of the orbiting scroll, so that a height of the first key cannot be limited by a height of the fixing protrusion that protrudes from the one axial side surface of the Oldham ring, and a depth or width of the first key that is press-fitted or bonded to the orbiting scroll can be deeply widely secured.

Sixth, since the first key has a rectangular cross-sectional shape, the first key can be prevented from being separated from or rotating in vain in the fixing groove.

Seventh, since the orbiting scroll into which the first key is press-fitted is made of an aluminum material, machining convenience and precision for the fixing groove of the orbiting scroll into which the first key is press-fitted can be increased.

Eighth, since the first key is formed of an iron-based material, a coating layer does not have to be formed on a key part by using a lubricating material or the like. This can solve a problem such as separation, wear, etc. of the coating layer.

Ninth, since the first key is not exposed to outside of the slot while being received in the slot of the Oldham Ring during an orbiting motion of the orbiting scroll, a friction area of the key can be maintained constantly and a problem that surface pressure of the first key drastically increases can be solved.

Tenth, a shielding portion may be horizontally formed in a planar shape on one axial side of the slot to shield the one axial side of the slot. This can reinforce rigidity of the Oldham ring, in particular, rigidity of a surrounding portion of the slot.

In addition, the shielding portion closes the one axial side of the slot, such that oil can be introduced and stored in the slot. Accordingly, the oil stored in the slot can lubricate between the first key and the slot of the Oldham ring to reduce friction therebetween.

Eleventh, since the first key is fastened to the fixing groove by means of a fastening member such as a press-fit pin or screw, even if clearance is generated due to machining error and assembly error when assembling the fixing groove of the second scroll and the first key, the first key can be prevented from being twisted in the fixing groove. This can minimize loss of a compression chamber due to the generation of the clearance between a fixed wrap and an orbiting wrap.

The first key is formed of a different material from a material of the second scroll and is fastened to the second scroll by a fastening member. Accordingly, the first key can be prevented from being separated from or rotating in vain in the fixing groove of the second scroll due to a difference in thermal expansion coefficient between the second scroll and the first key.

DETAILED DESCRIPTION

In the following description, a description of some components will be omitted to clarify features of the present disclosure.

1. Definition of Terms

It will be understood that when an element is referred to as being “connected with” another element, the element can be connected with the another element or intervening elements may also be present.

In contrast, when an element is referred to as being “directly connected with” another element, there are no intervening elements present.

The term “axial direction” used in the following description means an axial direction of a rotating shaft. The axial direction may be understood as the same concept as a vertical direction (Z-Z′) illustrated in the drawings.

The term “radial direction” used in the following description means a radial direction of the rotating shaft. The radial direction may be understood as a front-rear direction (X-X′) or a left-right direction (Y-Y′) illustrated in the drawings. In particular, a first radial direction may be understood as the same concept as the front-rear direction. The second radial direction may be understood as the same concept as the left-right direction perpendicular to the first radial direction.

2. Description of Configuration of Scroll Compressor According to One Embodiment

FIG.1is a conceptual view illustrating a cross-section of a scroll compressor in accordance with one embodiment of the present disclosure.

FIG.2is a conceptual view illustrating a structure in which a first key110press-fitted to an orbiting scroll39is slidable along a slot102of an Oldham ring100, inFIG.1.

FIG.3is a conceptual view illustrating a structure in which a second key120of the Oldham ring100is slidable along a key groove33of a frame30, inFIG.1.

FIG.4is a conceptual view illustrating a state in which the Oldham ring100is detached from the orbiting scroll39, inFIG.1.

FIG.5is a bottom view illustrating a state in which the first key110of the Oldham ring100slides along the slot102of the Oldham ring100while press-fitted to the orbiting scroll39, inFIG.4.

A scroll compressor according to an embodiment of the present disclosure includes a casing10, a motor part20, and a compression part29.

Hereinafter, each configuration of the scroll compressor according to the embodiment will be described with reference to the accompanying drawings, and the Oldham ring100will be described as a separate clause.

The casing10defines appearance of the compressor. The casing10may include a main housing11, an upper housing12, and a lower housing15.

The main housing11is formed in a cylindrical shape. The main housing11may be formed in a vertical (up/down) direction in a penetrating manner. An accommodation space is defined inside the main housing11.

The upper housing12may be coupled to an upper end portion of the main housing11to seal an upper end of the main housing11.

The lower housing15may be coupled to a lower end portion of the main housing11to seal a lower end of the main housing11.

The accommodation space of the main housing11may be sealed by the upper housing12and the lower housing15.

A discharge pipe14for discharging refrigerant is provided in the upper housing12.

The discharge pipe14may be disposed in an upper central portion of the upper housing12or a side surface of the upper housing12. In this embodiment, the discharge pipe14is connected to the upper central portion of the upper housing12to protrude upward.

The discharge pipe14communicates with a second space17to be described later.

A suction pipe13for suctioning refrigerant may be provided in the upper housing12or the lower housing15. This embodiment illustrates a structure in which the suction pipe13is disposed in the upper housing12.

The suction pipe13may extend downward from one side of the upper housing12to communicate with a suction chamber of a compression space. The suction pipe13may be spaced apart from the discharge pipe14to one side. A through hole through which the suction pipe13is inserted may be formed to be spaced apart from the central portion of the upper housing12to one side. Refrigerant may be suctioned into a suction chamber of a compression chamber42through the suction pipe13.

The compression chamber42is formed between an orbiting scroll39and a fixed scroll34, which will be described later.

An inside of the casing10may be divided into a motor space (hereinafter, a first space16) and an oil separation space (hereinafter, a second space17) with the compression part29interposed therebetween.

The main housing11and the lower housing15may define the first space16together with one side surface of the compression part29. The motor part20may be installed in the first space16.

The upper housing12may define the second space17together with another side surface of the compression part29. The second space17may be temporarily filled with refrigerant.

The first space16and the second space17may communicate with each other by a communication hole18and a communication groove19.

The communication hole18is formed through an outer circumferential surface of the compression part29to be described later in an axial direction. The communication hole18may be provided in plurality spaced apart in the circumferential direction along the outer circumferential surface of the compression part29.

The communication groove19is provided in plurality formed axially in a penetrating manner between an outer circumferential surface of the main housing11and an outer circumferential surface of a stator core22to be described later. The plurality of communication grooves19may be spaced apart from one another in a circumferential direction of the stator core22.

The communication holes18and the communication grooves19may communicate with each other and may be disposed to be spaced apart from each other in the axial direction.

A portion of refrigerant discharged from the compression chamber42to the second space17may be discharged through the discharge pipe14.

Another portion of the refrigerant may move from the compression space sequentially to the first space16and the second space17, so as to be discharged through the discharge pipe14.

Oil may be filled inside the lower housing15by a preset height.

The motor part20generates rotational force. The motor part20may be implemented as a drive motor that receives electric energy and generates rotational force.

The motor part20is located inside the main housing11. The motor part20includes a stator21and a rotor24.

The stator21is fixedly disposed in the main housing11. The stator21includes a stator core22and a stator coil23. The stator core22may be formed by stacking a plurality of electrical steel sheets. The stator core22may be thermally press-fitted to an inner circumferential surface of the main housing11.

A plurality of slots102are axially formed through the stator core22.

The stator coil23is wound on the stator core22through the slots102.

The rotor24is accommodated inside the stator21with an air gap therebetween. The rotor24is disposed to be rotatable relative to the stator21.

The rotor24may include a rotor core25and a plurality of permanent magnets.

The rotor core25may be formed by stacking a plurality of electrical steel sheets. A plurality of magnet receiving holes may be axially formed through an inside of the rotor core25.

The permanent magnets may be accommodated and fixed in magnet accommodation holes.

A shaft receiving hole may be axially formed through a central portion of the rotor core25.

The rotating shaft26may be press-fitted to the shaft receiving hole of the rotor core25.

The rotating shaft26may extend from the shaft receiving hole of the rotor core25to protrude upward.

With the configuration, when power is applied to the stator coil23, a magnetic field is generated around the stator coil23. The rotor24may generate rotational force by electromagnetic interaction with the stator21.

The rotor24may rotate relative to the stator21centering on the rotating shaft26.

The rotating shaft26may extend in the axial direction toward the compression part29in order to transmit the rotational force generated in the motor part20to the compression part29. The rotating shaft26may be rotatably supported inside the frame30of the compression part29to be described later.

An oil passage27may be provided inside the rotating shaft26. An oil pump28may be disposed beneath the rotating shaft26. Oil may be pumped up by the oil pump28to the compression part29through the oil passage27inside the rotating shaft26.

Since the oil pump28rotates together with the rotating shaft26, oil stored in the lower housing15can be pumped into the oil passage27of the rotating shaft26by using centrifugal force or viscosity.

The rotating shaft26may be coupled to the orbiting scroll39of the compression part29to be described later, so that the rotational force of the motor part20can be transmitted to the orbiting scroll39.

The compression part29may be disposed above the motor part20.

The compression part29compresses refrigerant by using the rotational force of the motor part20.

The compression part29includes a frame30, a fixed scroll (hereinafter, a first scroll34), and an orbiting scroll (hereinafter, a second scroll39). The fixed scroll34may be referred to as a first scroll34. The orbiting scroll39may be referred to as a second scroll39.

The frame30may be fixedly coupled to an upper open end portion of the main housing11.

The first scroll34is fixedly supported on an upper surface of the frame30. The first scroll34may be fixedly coupled to the casing10together with the frame30.

The second scroll39is pivotably supported on the upper surface of the frame30to perform an orbiting motion between the first scroll34and the frame30.

The second scroll39is eccentrically coupled to an eccentric shaft of the rotating shaft26. The second scroll39forms a pair of compression chambers42each having a suction chamber, an intermediate pressure chamber, and a discharge chamber while performing an orbiting motion relative to the first scroll34.

The frame30includes a frame end plate31and a frame side wall portion32.

The frame end plate31may be formed in a disk shape.

The frame side wall portion32protrudes toward the first scroll34from an upper surface of the frame end plate31. The frame side wall portion32may be coupled to a side wall portion51of the first scroll34to be described later.

A frame thrust surface may be formed horizontally on an inner side of the frame side wall portion32. The second scroll39may be mounted on the frame thrust surface and supported in the axial direction. Here, the axial direction means an extension direction of the rotating shaft26.

A back pressure space may be formed in a center of the frame thrust surface. A portion of refrigerant compressed in the compression chamber42may be filled in the back pressure space together with oil to support a rear surface (lower surface) of the second scroll39.

An oil passage27may be defined inside the rotating shaft26.

The oil passage27may extend axially from the rotating shaft26. An upper end portion of the oil passage27may be connected to communicate with the back pressure space.

A shaft hole of the frame30through which the rotating shaft26is inserted is formed in the middle of the back pressure space. A first bearing (no reference numeral given) may be provided on an inner circumferential surface of the shaft hole of the frame30.

The first bearing may be configured as a bush bearing. Alternatively, in some cases, it may be implemented as a ball bearing. However, compared to the ball bearing, the bush bearing can be advantageous in terms of cost because it is cheaper than the ball bearing, can be easy to be assembled, and can also reduce weight and noise.

Accordingly, pressure in the back pressure space forms intermediate pressure between pressure in the suction space and final pressure (i.e., discharge pressure) in the compression chamber42.

A key groove33may be formed inside the frame thrust surface. A second key120of the Oldham ring100to be described later may be slidably inserted into the key groove33of the frame30.

Meanwhile, the first scroll34may be fixedly coupled to the frame30or press-fitted to the casing10.

The first scroll34may include a fixed scroll end plate (hereinafter, a first end plate35), a fixed scroll side wall portion (hereinafter, a first side wall portion37), and a fixed scroll wrap (hereinafter, a first wrap38). The fixed scroll end plate35may be referred to as a first end plate35. The fixed scroll side wall portion37may be referred to as a first side wall portion37. The fixed scroll wrap38may be referred to as a fixed wrap or first wrap38.

The first end plate35may be formed approximately in a disk shape.

The first side wall portion37may extend from a rim of the first end plate35along the circumferential direction. The first side wall portion37may extend downward from the first end plate35to be coupled to the frame side wall portion32.

The first wrap38may protrude from a lower surface of the first end plate35. The first wrap38may spirally extend from the lower surface of the first end plate35in a direction from a radially outside to a radially inner central portion.

The first wrap38may be engaged with an orbiting scroll wrap (hereinafter, a second wrap41) to be described later.

A suction passage may be defined at one side of the first side wall portion37so that a suction space and a suction chamber (no reference numeral given) communicate with each other.

A discharge port36may be formed through a central portion of the first end plate35. The discharge port36may be connected to communicate with the discharge chamber. Compressed refrigerant may be discharged to the discharge space or the oil separation space17through the discharge port36.

Meanwhile, the second scroll39may be disposed between the frame30and the first scroll34.

The second scroll39includes an orbiting scroll end plate (hereinafter, a second end plate40), a second wrap41, and a boss portion43. The orbiting scroll end plate40may be referred to as a second end plate40. The orbiting scroll wrap41may be referred to as an orbiting wrap or second wrap41.

The second end plate40may be formed approximately in a disk shape.

The second wrap41may protrude upward from an upper surface of the second end plate40to face the lower surface of the first end plate35. The second wrap41may be disposed to overlap the first wrap38in the radial direction and engaged with the first wrap38.

The second wrap41may spirally extend from the lower surface of the second end plate40in a direction from a radially outside to a radially inner central portion.

The first wrap38and the second wrap41may be formed in an involute shape, but may also be formed in various other shapes.

A scroll thrust surface that defines the thrust surface together with the frame thrust surface may be formed on a rear surface (lower surface) of the second end plate40.

However, since the second scroll39rises with respect to the frame30when the compressor is driven, the frame thrust surface and the scroll thrust surface do not substantially contact each other.

Rather, the frame30and the second scroll39form a thrust surface with a ring body101of the Oldham ring100to be described later.

The boss portion43may protrude downward from a central portion of a lower surface of the second end plate40toward the rotating shaft26.

An eccentric shaft may protrude from an upper end portion of the rotating shaft26. The eccentric shaft may protrude upward eccentrically from the center of the rotating shaft26.

An eccentric shaft accommodating hole may be eccentrically formed in the boss portion43.

Since the eccentric shaft is inserted into the eccentric shaft accommodating hole, the boss portion43may be eccentrically coupled to the eccentric shaft.

With this configuration, as the eccentric shaft of the rotating shaft26is eccentrically coupled to the boss portion43of the second scroll39, the rotating shaft26can transmit the rotational force to the second scroll39of the compression part29.

(4) One Embodiment of Oldham Ring100

An anti-rotation mechanism is installed between the frame30and the second scroll39to prevent rotation of the second scroll39. In some cases, the anti-rotation mechanism may alternatively be disposed between the first scroll34and the second scroll39. Hereinafter, a case in which the anti-rotation mechanism is disposed between the frame30and the second scroll39will be described as an example.

As for the anti-rotation mechanism, a pin-and-ring type may be applied or an Oldham ring type may be applied. This embodiment relates to a case in which the Oldham ring type is applied.

The Oldham ring100is configured to prevent the second scroll39from rotating.

Since the Oldham ring100prevents the second scroll39from rotating, the second scroll39can pivot relative to the first scroll34along with the rotation of the rotating shaft26.

Meanwhile, the scroll compressor may also be applied to an air conditioning system that controls humidity and temperature of air using a refrigeration cycle or a home appliance such as a refrigerator that generates cool air.

In order to improve motor efficiency of the scroll compressor, the Oldham ring100as well as the orbiting scroll39may be made of a lightweight material such as aluminum (aluminum alloy).

However, as described above, when the Oldham ring100and the frame30or the orbiting scroll39that is in contact with the Oldham ring100are formed of an aluminum material, deterioration of friction characteristics may be seriously caused due to the same type of material, unlike cast iron.

In consideration of this, a method in which a ring part and a key part of the Oldham ring100are formed of different materials and assembled to each other or a method of forming the entire Oldham ring100with a single (same) material and thereafter forming a coating layer on a surface of the Oldham ring100to improve friction characteristics may be taken into account.

However, as described above, these methods have limitations in machinability and reliability.

Therefore, the present disclosure desires to enhance machinability for the Oldham ring100by forming the entire Oldham ring100with a single material, i.e., aluminum, and simultaneously secure reliability of the compressor by forming the orbiting scroll39, to which the Oldham ring100is coupled, with the same material as the Oldham ring100to prevent beforehand deterioration of friction characteristics due to the use of the same material.

In this embodiment, the frame30may be formed of an iron-based material.

To this end, the first key110is disposed on the second scroll39. The first key may be mounted on the second end plate40. Two of the first keys110may be mounted on the second end plate40of the second scroll39.

The plurality of first keys110may be disposed on the second end plate40of the second scroll39to be spaced apart from each other in the circumferential direction. The plurality of first keys110may be spaced apart from each other at an interval of 180 degrees in the circumferential direction. The plurality of first keys110may be radially spaced apart from each other at the interval of 180 degrees at opposite sides on the second end plate40. The first keys110may be disposed on a middle of the scroll thrust surface of the second scroll39.

The first key110may have a bar-like shape that has a solid rectangular cross-section and extends long in the vertical (up/down) direction. The cross-sectional shape of the first key110is not limited to the rectangular shape but may alternatively be formed in a circular shape. However, the first key110is preferably formed in a rectangular shape to be prevented from rotating in vain due to getting twisted in the fixing groove44in the circumferential direction.

The first key110may be press-fitted to the second end plate40. An upper side of the first key110may be fixedly inserted into the second end plate40in a thickness direction, and a lower side of the first key110may protrude downward from the lower surface of the second end plate40.

The plurality of first keys110may protrude from the lower surface of the second end plate40toward the slot102of the Oldham ring100.

A fixing groove44for fixing the first key110to the second end plate40may be formed to be recessed in the second end plate40in the thickness direction. The fixing groove44may have a rectangular cross-sectional shape. Corners of the rectangular fixing groove44may be rounded.

A cross-sectional aera of the fixing groove44may be the same as a cross-sectional area of the first key110.

A depth of the fixing groove44may be smaller than a thickness of the second end plate40. The depth of the fixing groove44is smaller than a length of the first key110.

With this configuration, the first key110can be press-fitted to the second end plate40.

Since the first key110is press-fitted to the second end plate40, the first key110can be fixed in the second end plate40with its movement limited in the vertical (axial) direction or in front-rear and left-right directions (radial direction).

The first key110may operate integrally with the second scroll39.

The first key110may be formed of a material different from that of the second scroll39and the Oldham ring100. For example, the first key110may be made of an iron-based material. The first key110may be formed of cast iron (including cast iron alloy) or an iron-based sintered alloy.

The Oldham ring100may include a ring body101, a slot102, and a second key120.

The ring body101may be formed in a circular ring shape. The ring body101includes an outer circumferential surface, an inner circumferential surface, one axial side surface and another axial side surface.

The outer circumferential surface of the ring body101is formed in a curved shape having a predetermined curvature in the circumferential direction along an outermost circumference of the ring body101. The inner circumferential surface of the ring body101is formed in a curved shape having a predetermined curvature in the circumferential direction along an innermost circumference of the ring body101.

The outer and inner circumferential surfaces of the ring body101are closed curved surfaces.

The one axial side surface (Z direction, upper surface) of the ring body101faces the second end plate40of the second scroll39and is formed as a horizontal plane.

The another axial side surface (Z′ direction, lower surface) of the ring body101faces an opposite side of the second end plate40and is formed as the horizontal plane.

A plurality of first protrusions104may be provided on the outer circumferential surface of the ring body101. The plurality of first protrusions104protrude radially outward from the outer circumferential surface. each of the first protrusions104may include a first planar portion1041and a plurality of first inclined portions1042.

The first planar portion1041is formed to be planar in a tangential direction with respect to the outer circumferential surface of the ring body101.

The plurality of first inclined portions1042are disposed at both sides of the first planar portion1041with the first planar portion1041interposed therebetween. One end of each of the first inclined portions1042is connected to the first planar portion1041, and another end of the first inclined portion1042is connected to the outer circumferential surface of the ring body101. The first inclined portion1042is inclined radially outward from the outer circumferential surface toward the first planar portion1041.

The plurality of first protrusions104are spaced apart from each other at an equal interval in the circumferential direction along the outer circumferential surface of the ring body101. The plurality of first protrusions104may be four that are disposed to be spaced apart from one another at intervals of 90 degrees.

A plurality of second protrusions105may be provided on the inner circumferential surface of the ring body101.

Each of the plurality of second protrusions105may include a second planar portion1051and a plurality of second inclined portions1052.

The second planar portion1051is disposed radially more inward than the inner circumferential surface of the ring body101. The second planar portion1051is formed to be planar in the tangential direction of the inner circumferential surface.

One end of each of the second inclined portions1052is connected to the second planar portion1051, and another end of the second inclined portion1052is connected to the inner circumferential surface of the ring body101. The second inclined portion1052is inclined radially inward from the inner circumferential surface of the ring body101toward the second planar portion1051.

The second protrusion105has a longer protrusion length than the first protrusion104.

The second inclined portion1052has a greater inclination than the first inclined portion1042.

The plurality of second inclined portions1052may be spaced apart from each other at an interval of 180 degrees along the inner circumferential surface of the ring body101.

The plurality of second protrusions105may be disposed to radially face some of the plurality of first protrusions104.

According to this configuration, a radial width of the axial side surface of the ring body101is the widest between the first protrusion104and the second protrusion105.

The radial width between the first protrusion104and the second protrusion105is wider than a radial width between the first protrusion104and the inner circumferential surface of the ring body101.

The plurality of slots102may be formed in a radially elongated rectangular shape in the axial side surface of the ring body101. The plurality of slots102may be formed through the ring body101in a thickness direction or axial direction of the ring body101. Each corner of the slot102may be rounded into a curved shape.

The plurality of slots102are disposed between the plurality of first protrusions104and second protrusions105, respectively.

The slot102may extend long in the radial direction of the ring body101between the first protrusion104and the second protrusion105. A radial length (longitudinal) of the slot102may be longer than its width (transverse).

A radial side surface and a widthwise side surface of the slot102may be disposed perpendicular to each other. The widthwise side surface of the slot102may be formed parallel to the first planar portion1041of the first protrusion104and the second planar portion1051of the second protrusion105.

The first key110is received inside the slot102. A length of the first key110may be shorter than or equal to a depth of the fixing groove44and an axial depth of the slot102.

The first key110is disposed to be slidable along an inner surface of the slot102.

In a rectangular cross-section of the first key110, a transverse or longitudinal length of the first key110is formed to be the same as or almost similar to the width of the slot102. A transverse side surface or longitudinal side surface of the first key110is made to be in surface contact with the radial side surface of the slot102.

The transverse or longitudinal length of the first key110may be formed to be about half the radial length of the slot102.

A transverse length of the slot102may be about half a longitudinal length of the slot102.

The first key110may slide in the radial direction of the ring body101along the slot102. According to this configuration, the orbiting scroll39can perform a relative motion (sliding motion) with respect to the Oldham ring100.

The plurality of second keys120protrude toward the frame end plate31from the another axial side surface of the ring body101that faces the opposite side to the orbiting scroll39.

The second key120may be formed in a rectangular shape. A longitudinal length of the second key120in the radial direction may be longer than its transverse length in the widthwise direction.

The second key120may be disposed between the first protrusion104and the inner circumferential surface of the ring body101.

The plurality of second keys120may be disposed to be spaced apart from the plurality of first keys110at intervals of 90 degrees in the circumferential direction. The plurality of second keys120may be disposed to be spaced apart from the plurality of first keys110at intervals of 90 degrees in the circumferential direction.

A plurality of key grooves33are recessed in the frame end plate31in the thickness direction or the axial direction.

The plurality of key grooves33may extend long in the radial direction of the frame end plate31.

The second key120may be received in the key groove33of the frame30. The second key120may be disposed to be radially slidable along the key groove33.

The key grooves33and the slots102may be alternately disposed to be spaced apart from each other at intervals of 90 degrees in the circumferential direction of the ring body101. The key groove33and the slot102may be perpendicularly disposed.

As the second key120slides along the key groove33of the frame30, the Oldham ring100may perform a relative motion (sliding motion in the radial direction) relative to the frame30.

The plurality of first keys110and second keys120may be alternately disposed to be spaced apart from each other in the circumferential direction of the ring body101.

Sliding directions of the first key110and the second key120may be made perpendicular to each other.

The first key110may slide along the slot102of the Oldham ring100in a first radial direction, and the second key120may slide along the key groove33of the frame30in a second radial direction perpendicular to the first radial direction.

The first radial direction may be understood as the same concept as a front-rear direction (X-X′ direction). The second radial direction may be understood as the same concept as a left-right direction (Y-Y′ direction).

The second scroll39may slide relative to the Oldham ring100in the first radial direction, and the Oldham ring100may slide relative to the frame30in the second radial direction.

According to this, the Oldham ring100can prevent the second scroll39from rotating, so that the second scroll39can perform an orbiting motion relative to the first scroll34with being engaged with the first scroll34without rotating centering on the first scroll34.

Therefore, according to the present disclosure, the Oldham ring100can be formed of an aluminum material that is the same as the material of the orbiting scroll39, thereby improving motor efficiency by reducing a weight of the Oldham ring100.

In addition, the first key110protrudes from the lower surface of the orbiting scroll39toward the Oldham ring100. The first key110may slide along the slot102while being received in the slot102formed in the Oldham ring100. The first key110is formed of an iron-based material that is different from the material of the orbiting scroll39.

According to this configuration, even if the Oldham ring100is made of the same material as the orbiting scroll39, only the first key110of the orbiting scroll39that rubs against the slot102of the Oldham ring100can be made of the iron-based material that is different from the material of the orbiting scroll39, thereby improving friction/wear characteristics.

This is not a structure in which a first key covers at least one side surface of a fixing protrusion protruding from one axial side surface of an Oldham ring, but an integrated structure in which the first key110protrudes from the second end plate40of the orbiting scroll39to be received in the slot102of the Oldham ring100. This can increase support stiffness and rigidity of the first key110without reducing the thickness of the first key110.

In addition, the transverse or longitudinal length of the first key110may be the same as or similar to the width of the slot102.

In addition, since the first key110does not have the structure in which the first key110is coupled to the fixing protrusion protruding from the one axial side surface of the Oldham ring100, a generation of clearance due to a machining error and an assembly error between the fixing protrusion and the first key110of the Oldham ring100can be prevented.

In addition, the first key110is press-fitted into the fixing groove44formed in the second end plate40of the orbiting scroll39. Accordingly, a height of the first key110is not limited to a height of the fixing protrusion protruding from the one axial side surface of the Oldham ring100, and a deep depth or wide width of the first key110that is press-fitted or bonded to the orbiting scroll39can be secured.

In addition, since the first key110has a rectangular cross-sectional shape, the first key110can be prevented from being separated from or rotating in vain in the fixing groove44.

Moreover, since the orbiting scroll39into which the first key110is press-fitted is made of aluminum, machining convenience or precision for the fixing groove44of the orbiting scroll39into which the first key110is press-fitted can increase.

Since the first key110is formed of the iron-based material, a coating layer does not have to be formed on the key part by using a lubricating material or the like. This can solve a problem such as separation, wear, etc. of the coating layer.

While the orbiting scroll39pivots, the first key110is not exposed to the outside of the slot102in a state where it is received in the slot102of the Oldham ring100. Therefore, a friction area of the key can be constantly maintained and a drastic increase in surface pressure of the first key110can be solved.

(5) Another Embodiment of Oldham Ring200

FIG.6is a conceptual view illustrating a structure in which one axial side of a slot202is closed, in another embodiment of an Oldham ring200according to the present disclosure.

FIG.7is a partially enlarged view illustrating a state in which one axial side of the slot202is closed inFIG.6.

This embodiment is different from the embodiment ofFIGS.1to5in terms of a structure in which the slot202of the Oldham ring200is axially open toward the first key110and closed toward the frame30.

The one axial side of the slot202may be formed in a closed structure with respect to the frame30.

A shielding portion203may be formed horizontally in a planar shape, while maintaining a predetermined thickness, on one axial side of the slot202to shield the one axial side of the slot202.

According to this configuration, the shielding portion203can increase rigidity of the Oldham ring200, in particular, rigidity of a surrounding portion of the slot202.

In addition, the shielding portion203closes the one axial side of the slot202, such that oil can be introduced and stored in the slot202. Accordingly, the oil stored in the slot202can lubricate between the first key110and the slot202of the Oldham ring200to suppress friction therebetween.

Since other components are the same as or similar to those in the embodiment ofFIGS.1to5, duplicated descriptions will be omitted.

In the embodiment illustrated inFIGS.6and7, the frame30may be formed of an iron-based material such as cast iron.

(6) Still Another Embodiment of Oldham Ring300

FIG.8is a conceptual view illustrating a state in which a first key310and a second key320are received in a first slot302and a second slot303of an Oldham ring300, in still another embodiment of the Oldham ring300according to the present disclosure.

FIG.9is a perspective view illustrating a state in which a plurality of first and second slots302and303are formed through the Oldham ring300in the axial direction inFIG.8.

InFIG.8, a left side based on an axial center line O-O′ of a rotating shaft is a cross-sectional view illustrating a state in which the first key310disposed on the second scroll39is received in the first slot302of the Oldham ring300, and a right side is a cross-sectional view illustrating a state in which the second key320disposed on the frame30is received in the second slot303of the Oldham ring300. The left cross-section and the right cross-section are perpendicular to each other.

In this embodiment, the Oldham ring300is different from the embodiments ofFIGS.1to7in that the Oldham ring300includes a plurality of first slots302and a plurality of second slots303without having the second key320disposed on a ring body301.

The plurality of first slots302may be spaced apart from each other at an interval of 180 degrees in the circumferential direction of the ring body301. The first key310may be press-fitted to the scroll thrust surface of the second scroll39toward an opposite side to the first scroll34.

A first fixing groove344may be formed in the second end plate40. The first key310may be press-fitted to the first fixing groove344.

The first key310may be received in the first slot302, to slide along the first slot302during the orbiting motion of the second scroll39.

The plurality of second slots303may be perpendicular to the plurality of first slots302. The plurality of second slots303may be spaced apart from each other at an interval of 180 degrees in the circumferential direction of the ring body301.

The plurality of first keys310and the plurality of second keys320may be alternately disposed to be spaced apart from each other at an equal interval in the circumferential direction of the ring body301.

The first slot302and the second slot303may be formed through the ring body301in a thickness direction or axial direction of the ring body301.

A first shielding portion may be further formed on one axial side of the first slot302to shield one side of the first slot302facing the frame end plate31(not illustrated).

A second shielding portion may be further formed on another axial side of the second slot303to shield another side of the second slot303facing the second end plate40of the second scroll39.

The second key320may be press-fitted to the frame end plate31or may be integrally formed with the frame end plate31.

This embodiment illustrates the state in which the second key320is press-fitted to the frame end plate31. A second fixing groove311may be formed in the frame end plate. The second key320may be press-fitted to the second fixing groove311.

The second key320may be received in the second slot303, to slide in a contact state with a side surface of the second key320during the orbiting motion of the second scroll39.

According to this configuration, while the second scroll39performs the orbiting motion, the first key310can slide in the first radial direction along the first slot302and the second scroll39can move relative to the Oldham ring300in the first radial direction.

In addition, the second slot303of the Oldham ring300can slide in the second radial direction in a contact state with the second key320, and the Oldham ring300can move relative to the frame30in the second radial direction that is perpendicular to the first radial direction.

Accordingly, the Oldham ring300can prevent the second scroll39from rotating, so that the second scroll39can pivot relative to the first scroll34.

In this embodiment, the frame30may be formed of aluminum that is the same material as that of the second scroll39and the Oldham ring300.

The first key310and the second key320may be formed of an iron-based material that is different from the material of the orbiting scroll39, the frame30, and the like.

According to the Oldham ring structure of this embodiment, the plurality of first slots and the plurality of second slots can be disposed with a phase difference of a 90-degree interval in the annular ring body or integrally connected to the ring body. This can simplify assembling between the first key and the second key that are disposed on the orbiting scroll and the frame, respectively, compared to the existing pin-and-ring type anti-rotation mechanism.

Since other components are the same as or similar to those in the embodiments ofFIGS.1to7, duplicated descriptions will be omitted.

(7) Various Embodiments Related to Fastening Structure of First Key110

{circle around (1)}FIG.10is a conceptual view illustrating a state in which the first key110is coupled to the orbiting scroll39by a bolt.

This embodiment is different from the embodiments ofFIGS.1to9in that the first key110is coupled to the second scroll39by a fastening member46such as a screw or the like.

A fastening groove47may be recessed axially in one side of the first key110.

A first fastening hole45may be disposed on the second end plate40of the second scroll39. The first fastening hole45may be formed through the second end plate40in the thickness direction to communicate with the fixing groove44.

The first key110can be inserted into the fixing groove44of the second end plate40, and the screw can be inserted and fastened into the fastening groove47of the first key110through the first fastening hole45.

The first fastening hole45may be recessed into the second end plate40of the second scroll39to face the first scroll34. A head of the screw may be received in the first fastening hole45, so as to be buried inside the second end plate40.

Since other components are the same as or similar to those in the embodiments ofFIGS.1to9, duplicated descriptions will be omitted.

{circle around (2)}FIG.11is a conceptual view illustrating a state in which the first key110is coupled to the orbiting scroll39by a press-fit pin49.

This embodiment is different from the embodiments ofFIGS.1to9in that the first key110is coupled to the second scroll39by a fastening member46such as a press-fit pin49.

A second fastening hole112may be formed through one side of the first key110in the radial direction.

A fastening groove47may be disposed in the second end plate40of the second scroll39. The fastening groove47may extend radially in the second end plate40to communicate with the fixing groove44. The fastening groove47may extend in a direction of crossing the fixing groove44in the radial direction.

An outer side of the fastening groove47may be connected to communicate with an outer side of the second end plate40.

The first key110and the second end plate40can be fastened by inserting the first key110into the fixing groove44of the second end plate40and inserting the press-fit pin49through the second fastening hole112of the first key110via the fastening groove47of the second end plate40.

The press-fit pin49may be installed to be buried inside the second end plate40.

According to this configuration, even if a clearance is generated due to a machining error and an assembly error when assembling the fixing groove39of the second scroll39and the first key110, the first key1110can be fastened to the fixing groove44by the fastening member46(or the press-fit pin49), thereby preventing the first key110from being twisted in the fixing groove44. This can minimize loss of the compression chamber42due to the generation of the clearance between the fixed wrap38and the orbiting wrap41.

As the first key110is formed of the different material from that of the second scroll39, and is fastened to the second scroll39by the fastening member46(or the press-fit pin49), the problem that the first key110is separated from or rotates in vain in the fixing groove44due to a difference in thermal expansion coefficient between the second scroll39and the first key110can be prevented.

Since other components are the same as or similar to those in the embodiments ofFIGS.1to9, duplicated descriptions will be omitted.

(8) Embodiment of a Structure that a First Key Groove Forming Part54, which is Formed of a Different Material from a Material of the Orbiting Scroll39and Receives Therein a First Key410of an Oldham Ring400, is Applied to the Orbiting Scroll39

FIG.12is a cross-sectional view illustrating a state in which a first key groove55for preventing wear is applied between an Oldham ring400and the orbiting scroll39.

FIG.13is a perspective view illustrating a state in which the orbiting scroll39, the first key groove55for preventing wear, and the Oldham ring400are disassembled, inFIG.12.

A plurality of first key groove mounting parts50are disposed in the scroll thrust surface, which is the bottom surface of the second scroll39.

The plurality of first key groove mounting parts50may be disposed to be spaced apart from each other at an interval of 180 degrees in the circumferential direction of the second end plate40.

The first key groove mounting part50is recessed into the bottom surface of the second end plate40of the second scroll39in the thickness direction. The first key groove mounting part50may extend long in the radial direction of the second end plate40. A radial length of the first key groove mounting part50is longer than its width.

An outer end portion of the first key groove mounting part50may be open radially outward. An inner end portion of the first key groove mounting part50is disposed to be spaced apart from the boss portion43in the radial direction. The inner end portion of the first key groove mounting part50has a structure closed with respect to the boss portion43.

The inner end portion of the first key groove mounting part50may be formed in a circular curved shape.

A depth of the first key groove mounting part50is smaller than the thickness of the second end plate40.

The first key groove mounting part50may include a plurality of side walls51, an inner curved surface portion52, and a horizontal surface portion53.

The plurality of side walls51face each other with a spacing therebetween in a direction perpendicular to the radial direction. Each of the plurality of side walls51extends in the radial direction of the second end plate40.

The inner curved surface portion52is formed in a semicircular curved shape. One end of the inner curved surface portion52is connected to one end of one of the plurality of side walls51, and another end of the inner curved surface portion52is connected to one end of the other of the plurality of side walls51, so that the plurality of side walls51can be connected to each other.

The horizontal surface portion53extends horizontally in a planar shape from upper ends of the plurality of side walls51and the inner curved surface portion52.

The first key groove forming part54is received in the first key groove mounting part50. The first key groove forming part54is mounted on the first key groove mounting part50. An outer surface of the first key groove forming part54may be formed to correspond to a shape of the first key groove mounting part50along the side walls51and the inner curved surface portion52of the first key groove mounting part50. The first key groove forming part54may be press-fitted to the first key groove mounting part50or may be adhered by an adhesive element such as an adhesive.

A first key groove55is formed inside the first key groove forming part54. The first key groove forming part54may be formed of a material different from a material of the orbiting scroll39. For example, the first key groove forming part54may be made of an iron-based material.

The first key groove forming part54includes a plurality of side wall plates56, an inner plate57, and a horizontal plate58.

The plurality of side wall plates56face each other with a spacing therebetween in a direction perpendicular to the radial direction. Each of the plurality of side wall plates56extends in the radial direction of the second end plate40.

Each of the plurality of side wall plates56extends to have the same length as the side wall51of the first key groove mounting part50and has a preset thickness. The first key groove55is formed between the plurality of side wall plates56.

Thickness and length of each side wall plate56and a spacing between the plurality of side wall plates56facing each other may define length and width of the first key groove55. A height of the side wall plate56may define a depth of the first key groove55.

The inner plate57is formed in a semicircular curved shape. One end of the inner plate57is connected to one end of one of the plurality of side wall plates56, and another end of the inner plate57is connected to one end of the other of the plurality of side wall plates56, so that the plurality of side wall plates56can be connected to each other.

The horizontal plate58extends horizontally in a planar shape from upper ends of the plurality of side wall plates56and the inner plate57. A thickness of the horizontal plate58may define the depth of the first key groove55as well as the height of the side wall plate56.

The horizontal plate58can connect the upper ends of the plurality of side wall plates56, respectively, thereby increasing rigidity of the first key groove forming part54.

In addition, the horizontal plate58may connect open-side end portions of the plurality of side wall plates56, such that the plurality of side wall plates56can maintain a constant distance therebetween and deformation of the side wall plates56can be minimized.

In addition, the horizontal plate58may have a structure in which one side of the first key groove forming part54in the axial direction is blocked.

The thickness of each of the side wall plate56, the inner plate57, and the horizontal plate58should be able to sufficiently secure rigidity to withstand external shocks well and to minimize the occurrence of deformation.

The thicknesses of the plurality of side wall plates56and the inner plate57are the same or similar.

The thicknesses of the side wall plate56and the horizontal plate58may be different from each other.

For example, the horizontal plate58may be formed to be thinner than the side wall plate56.

The first key groove forming part54may be press-fitted to the first key groove mounting part50.

According to the embodiment ofFIGS.1to5, an inner or outer diameter of the Oldham ring may increase more than that of the related art Oldham ring, and a difficulty in securing a sufficient wall thickness around the slot102of the Oldham ring100may occur.

However, according to this embodiment, the related art (existing) Oldham ring400can be used as it is and also the aforementioned problems can be improved.

The Oldham ring400may include a ring body401, a first key410, and a second key420.

The ring body401may be formed in a circular ring shape. The ring body401includes an outer circumferential surface, an inner circumferential surface, one axial side surface (Z-axis direction, upper surface), and another axial side surface (Z-axis direction, lower surface).

The outer circumferential surface of the ring body401is formed in a curved shape having a predetermined curvature in the circumferential direction along an outermost circumference of the ring body401. The inner circumferential surface of the ring body401is formed in a curved shape having a predetermined curvature in the circumferential direction along an innermost circumference of the ring body401.

The outer and inner circumferential surfaces of the ring body401are closed curved surfaces.

The one axial side surface of the ring body401faces the second end plate40of the second scroll39and is formed as a horizontal plane.

The another axial side surface of the ring body401faces an opposite side of the second end plate40, i.e., the back pressure space of the frame30, and is formed as a horizontal plane.

A plurality of protrusions404may be provided on the outer circumferential surface of the ring body401. The plurality of protrusions404protrude radially outward from the outer circumferential surface. Each of the plurality of protrusions404may include a planar portion4041and a plurality of inclined portions4042.

The planar portion4041is formed to be planar in a tangential direction with respect to the outer circumferential surface of the ring body401.

The plurality of inclined portions4042are disposed on both sides of the planar portion4041with the planar portion4041interposed therebetween. One end of each inclined portion4042is connected to the planar portion4041, and another end of the inclined portion4042is connected to the outer circumferential surface of the ring body401. The inclined portion4042is inclined radially outward from the outer circumferential surface toward the planar portion4041.

The plurality of protrusions404are spaced apart from each other at an equal interval in the circumferential direction along the outer circumferential surface of the ring body401. The plurality of protrusions404may be four that are disposed to be spaced apart from one another at intervals of 90 degrees.

The plurality of first keys410protrude from the one axial side surface (upper surface in Z-axis direction) of the ring body401to be received in the plurality of first key grooves55. The plurality of first keys410are spaced apart from each other on the one axial side surface of the ring body401at an interval of 180 degrees in the circumferential direction.

The first key410is disposed to be slidable along an inner surface of the first key groove55.

In a rectangular cross-section of the first key410, a transverse or longitudinal length of the first key410is formed to be the same as or almost similar to the width of the first key groove55. A transverse side surface or longitudinal side surface of the first key410is made to be in surface contact with a radial side surface of the first key groove55, i.e., an inner surface of the side wall plate65.

The plurality of first keys410may slide in the radial direction of the ring body401along the first key grooves55. According to this configuration, the orbiting scroll39can perform a relative motion (sliding motion) with respect to the Oldham ring400.

The plurality of second keys420protrude toward the frame end plate31from the another axial side surface of the ring body401that faces the opposite side to the orbiting scroll39.

The plurality of second keys420are spaced apart from each other on the another axial side surface of the ring body401at an interval of 180 degrees in the circumferential direction.

The second key420may be formed in a rectangular shape. A longitudinal length of the second key420in the radial direction may be longer than its transverse length in the widthwise direction.

The first key410and the second key420may be disposed between the protrusion404and the inner circumferential surface of the ring body401.

The plurality of second keys420may be disposed to be spaced apart from the plurality of first keys410at intervals of 90 degrees in the circumferential direction.

A plurality of second key grooves may be recessed in the frame end plate31in the thickness direction or the axial direction, or a plurality of second key groove mounting parts and a plurality of second key groove forming parts may be press-fitted to the plurality of second key grooves. In the latter case, second key grooves may be formed inside the second key groove forming parts.

This embodiment illustrates a state in which the plurality of second key grooves are recessed in the thickness direction.

The frame30may be formed of an iron-based material.

The plurality of key grooves33may extend long in the radial direction of the frame end plate31.

The second key420may be received in the key groove of the frame30. The second key420may be disposed to be radially slidable along the key groove.

The first key groove55and the second key groove may be alternately disposed to be spaced apart from each other at an interval of 90 degrees in the circumferential direction of the ring body401when projected in the axial direction. The first key groove55and the second key groove may be perpendicularly disposed.

As the second key420slides along the second key groove of the frame30, the Oldham ring400may perform a relative motion (sliding motion in the radial direction) relative to the frame30.

Sliding directions of the first key410and the second key420may be made perpendicular to each other.

The first key410may slide along the first key groove55of the second scroll39in the first radial direction, and the second key420may slide along the second key groove of the frame30in the second radial direction perpendicular to the first radial direction.

The second scroll39may slide relative to the Oldham ring400in the first radial direction, and the Oldham ring400may slide relative to the frame30in the second radial direction.

According to this, the Oldham ring400can prevent the second scroll39from rotating, so that the second scroll39can perform an orbiting motion relative to the first scroll34with being engaged with the first scroll34without rotating centering on the first scroll34.

Therefore, according to the present disclosure, the first key groove forming part54provided in the orbiting scroll39defines the first key groove55for receiving the first key410of the Oldham ring400, and the first key groove forming part54is formed of a different material such as an iron-based material, which has excellent wear resistance, from the aluminum material of the orbiting scroll39and the Oldham ring400, thereby improving friction characteristics.

In addition, the first key groove forming part54defining the first key groove55can have increased rigidity by virtue of its thick thickness, and an occurrence of deformation of the first key groove forming part54can be minimized when press-fitting the first key groove forming part54of the orbiting scroll39.

The first key groove forming part54has the structure with one axial side closed. Therefore, the horizontal plate58that defines a closed portion of the first key groove forming part54horizontally extends to shield the upper ends of the plurality of side wall plates56and the inner plate57defining the inner surfaces of the first key groove forming part54, thereby structurally increasing the rigidity of the first key groove forming part54.

In addition, each of the plurality of side wall plates56, the inner plate57, and the horizontal plate58that define the first key groove forming part54is made of the iron-based material having a thickness to ensure rigidity and excellent wear resistance, such that surface polishing can be allowed. This can improve surface roughness and assembly property. In addition, since the surface of the first key groove55is evenly polished, the first key410can smoothly slide without being stuck.

On the other hand, when the frame30is formed of aluminum in order to reduce the weight of the compressor, the second key groove forming part is formed of the different material such as the iron-based material having the excellent wear resistance, and is also applied to the frame end plate31, thereby improving the friction/wear characteristics between the second key420and the second key groove forming part. Since the second key groove forming part is the same as or similar to the first key groove forming part54except for the position where it is located, a redundant description of the second key groove forming part will be omitted.

Since other components are the same as or similar to those in the embodiment ofFIGS.1to5, duplicated descriptions will be omitted.

(9) Another Embodiment of First Key Groove Forming Part64that is Made of Different Material and Applied to Orbiting Scroll39

FIG.14is a conceptual view illustrating another embodiment of a first key groove forming part64made of a different material according to the present disclosure.

This embodiment is different from the embodiment ofFIGS.12and13in that a first key groove forming part64penetrates in the axial direction.

The first key groove forming part64according to this embodiment is similar to that of the embodiment ofFIGS.12and13in that it has a plurality of side wall plates66and an inner plate67, but different from the embodiment ofFIGS.12and13in that the horizontal plate58is excluded.

Since other components are the same as or similar to those in the embodiment ofFIGS.12to13, duplicated descriptions will be omitted.

(10) Various Embodiments Regarding Radial and Axial Separation Prevention Structure of First Key Groove Forming Part54,64that is Made of Different Material and Applied to Orbiting Scroll39

The present disclosure provides a radial and axial separation prevention structure for preventing the first key groove forming part54,64mounted on the first key groove mounting part50of the orbiting scroll39from being separated axially and radially from the first key groove mounting part50of the orbiting scroll39.

When a second key groove forming part is formed in the frame30, the second key groove forming part can be configured to have the same fastening structure as the first key groove forming part54,64. Accordingly, a description of the fastening structure of the second key groove forming part will be replaced with the radial and axial separation prevention structure of the first key groove forming part54,64.

Since other components are the same as or similar to those in the embodiment ofFIGS.12to13, duplicated descriptions will be omitted. Other components of various embodiments for the radial and axial separation prevention structure of the first key groove forming part54,64described below may be applied similarly.

{circle around (1)} One Embodiment of Radial and Axial Separation Prevention Structure of First Key Groove Forming Part54

FIG.15is a conceptual view illustrating a structure, to which an anti-separation member of the first key groove forming part54according to one embodiment of the present disclosure is applied.

In this embodiment, a separation prevention member may be implemented as a fastening member59such as a screw.

A fastening hole581may be formed in the horizontal plate58of the first key groove forming part54. The fastening hole581may be formed in a circular shape through the horizontal plate58in a thickness direction or axial direction to surround an outer circumferential surface of the fastening member59. A diameter of the fastening hole581may correspond to a diameter of a screw portion of the fastening member59.

A fastening groove531may be formed in the horizontal surface portion53of the first key groove forming part54. The fastening groove531may have the same diameter as the fastening hole581of the first key groove forming part54. The fastening groove531may overlap the fastening hole581of the first key groove forming part54in the axial direction.

With to this configuration, the fastening member59such as a screw is fastened to the fastening groove531of the first key groove mounting part50through the fastening hole581of the first key groove forming part54, thereby preventing the first key groove forming part54from being separated from the first key groove mounting part50in the radial and axial directions.

{circle around (2)} Another Embodiment of Radial and Axial Separation Prevention Structure of First Key Groove Forming Part54

FIG.16is a conceptual view illustrating a structure, to which an anti-separation member of the first key groove forming part54according to another embodiment of the present disclosure is applied.

In this embodiment, protrusions561are disposed on the side wall plates56of the first key groove forming part54as a separation prevention unit of the first key groove forming part54. The protrusions561may protrude from the side wall plates56of the first key groove forming part54toward the side walls51of the first key groove mounting part50, respectively.

The protrusions561may be formed in a shape of a circle, rectangle, etc., having a polygonal cross-section. This embodiment illustrates a case where the protrusion561is formed in a rectangular shape.

The plurality of protrusions561may protrude from the both side wall plates56of the first key forming part54, respectively.

The protrusions561may extend along a longitudinal direction of the side wall plates56of the first key groove forming part54.

Protrusion receiving grooves511are formed respectively in the side walls51of the first key groove mounting part50so that the protrusions561are inserted.

The protrusion receiving grooves511may be recessed into the side walls51of the first key groove mounting part50in a direction that the protrusions561protrude. Each of the protrusion receiving grooves511may have a size corresponding to the protrusion561and may face the protrusion561to be engaged with the same.

With this configuration, when assembling the first key groove forming part54, the plurality of protrusions561may be coupled into the protrusion receiving grooves511by sliding in the radial direction of the orbiting scroll.

The protrusions may be press-fitted to the protrusion receiving grooves511.

Accordingly, the protrusions561can prevent the first key groove forming part54from being separated from the first key groove mounting part50in the axial and radial directions.

{circle around (3)} Still Another Embodiment of Radial and Axial Separation Prevention Structure of First Key Groove Forming Part54

FIG.17is a conceptual view illustrating a structure, to which an anti-separation member of the first key groove forming part54according to still another embodiment of the present disclosure is applied.

In this embodiment, a fixing protrusion571is disposed on the inner plate57of the first key groove forming part54as a separation prevention unit of the first key groove forming part54. The fixing protrusion571may protrude from an outer circumferential surface of the inner plate57of the first key groove forming part54toward the inner curved surface portion of the first key groove mounting part50.

The fixing protrusion571may be formed in a shape of a circle, rectangle, etc., having a polygonal cross-section. This embodiment illustrates a case where the fixing protrusion571is formed in a circular shape.

The fixing protrusion571may extend to protrude from the inner plate5756of the first key groove forming part54in the radial direction. The fixing protrusion571may protrude from the inner plate57to the inside of the orbiting scroll in the radial direction.

A protrusion fixing groove521is disposed in the inner curved surface portion of the first key groove mounting part50so that the fixing protrusion571is inserted.

The protrusion fixing groove521may be recessed into the inner curved surface portion of the first key groove mounting part50in a direction that the fixing protrusion571protrudes. The protrusion fixing groove521may have a size corresponding to the fixing protrusion571and may face the fixing protrusion571to be engaged with the same.

With this configuration, when assembling the first key groove forming part54, the fixing protrusion571may be coupled into the protrusion fixing groove521by sliding in the radial direction of the orbiting scroll.

The fixing protrusion571may be press-fitted to the protrusion fixing groove521.

Accordingly, the protrusion571can prevent the first key groove forming part54from being separated from the first key groove mounting part50in the axial and radial directions.

The separation prevention units according to the embodiments ofFIGS.15to17may be applied separately or may be applied in combination. The separation prevention units according to the embodiments ofFIGS.15to17show examples applied to the first key groove forming part54that includes the plurality of side wall plates56, the inner plate57, and the horizontal plate58, but may be equally applied to the first key groove forming part54that merely includes the plurality of side wall plates56and the inner plate57.