The present invention relates to a scroll compressor.
In general, in scroll compressors, some sliding parts, such as a rotation-preventing mechanism and a drive bearing that supports a rotary shaft for driving an orbiting scroll, tend to be disposed at positions away from a flow path through which a fluid mixture of refrigerant and lubricant flows.
Therefore, various technologies have been proposed for supplying lubricant together with refrigerant to the above-described drive bearing etc., by forming, in a scroll compressor, an inner-circulation flow path for guiding sucked refrigerant to the drive bearing etc. (for example, see PTLs 1 and 2).
In the above-described technology disclosed in PTL 2, lubrication of the drive bearing etc. is performed by forming grooves (gas communication grooves) extending in the radial directions and disposed at regular intervals on a contact surface between an end plate of an orbiting scroll and a housing for accommodating the orbiting scroll etc.
Specifically, a fluid mixture of refrigerant and lubricant is supplied to the drive bearing etc. through the above-described gas communication grooves.
However, in the above-described technology disclosed in PTL 2, when the orbiting scroll orbits (revolves) one time, the gas communication grooves are completely closed one time by the end plate of the orbiting scroll. In other words, the flow of lubricant etc. flowing toward the drive bearing etc. through the gas communication grooves is temporarily blocked.
As a result, there is a problem in that the flow rate of lubricant etc. supplied to the drive bearing etc. is reduced, which may cause trouble, such as poor lubrication.
The present invention has been made in order to solve the above-described problem, and an object thereof is to provide a scroll compressor capable of improving the supply of lubricant to the sliding parts.
In order to achieve the above-described object, the present invention provides the following solutions.
The present invention provides a scroll compressor including: a housing; a fixed scroll that has a fixed end plate on which a spiral fixed wall is provided upright and that is fixed in the housing; an orbiting scroll that has an orbiting end plate on which a spiral orbiting wall is provided upright and that is supported in the housing so as to be able to orbit while being prevented from rotating, in a state where the orbiting wall is engaged with the fixed wall; a drive shaft that is rotatably supported by a bearing section provided in the housing and that transfers a rotational force to the orbiting scroll; a suction section that makes refrigerant containing lubricant flow into a suction chamber provided in the housing; and a plurality of supply flow paths that are provided on a sliding surface between the housing and the orbiting end plate and that are connected to the suction chamber, in which, in the vicinity of an outer end, in a radial direction, of a supply flow path extending toward the suction section, among the plurality of supply flow paths, a communication section that always ensures a connection between the suction chamber and the supply flow path is provided on at least one of the housing and the orbiting end plate.
According to the present invention, since the communication section is provided, lubricant can always be supplied to parts requiring lubrication, such as the bearing section. Furthermore, by providing the communication section in the vicinity of the suction section, it is possible to more reliably supply lubricant to the bearing section etc., compared with a case where the communication section is provided in another portion.
Specifically, with the communication section being provided, temporary blocking between the supply flow path and the suction chamber is prevented when the orbiting scroll orbits. Therefore, it is possible to always ensure the supply of lubricant to the bearing section etc. from the suction chamber via the supply flow path.
Furthermore, since the communication section is provided in the vicinity of the suction section, the momentum of refrigerant flowing into the suction chamber can be utilized to flow lubricant together with the refrigerant from the suction chamber into the supply flow path and to supply the lubricant to the bearing section etc.
In the above-described invention, it is preferable that the communication section provided on at least one of the housing and the orbiting end plate have a concave shape that is concave in the radial direction.
According to this structure, for example, compared with a case where the communication section extends in a circumferential direction of the drive shaft, it is possible to make refrigerant and lubricant flow from the suction chamber into the supply flow path without diverting them. Furthermore, since the communication section is formed as a narrow area, the communication section is easily formed.
In the above-described invention, it is preferable that the depth of the concave shape of the communication section provided on the orbiting end plate be smaller than the thickness of the fixed wall.
According to this structure, by setting a given limitation to the concave shape of the communication section, it is possible to prevent any influence on the formation of the compression chambers for compressing refrigerant and to suppress deterioration in compression performance of the scroll compressor.
Specifically, the face of the orbiting end plate facing the fixed scroll is brought into contact with the fixed wall, slides thereon, and forms the compression chambers for compressing refrigerant, together with the fixed scroll. Therefore, by limiting the depth of the concave shape of the communication section to be smaller than the thickness of the fixed wall, it is possible to separate the compression chambers and the communication section even when the compression chambers C move closest to the communication section.
In the above-described invention, it is preferable that the housing include a front housing having a substantially cylindrical shape having a bottom, which is almost closed at an orbiting scroll side and is open at a fixed-scroll side, and a rear housing that covers an opening of the front housing; and an end face of the communication section provided on the orbiting end plate be tilted inward in the radial direction from an orbiting end plate side toward a fixed-end-plate side, the end face facing the housing.
According to this structure, sufficient flow-path cross-sectional area of the communication section is ensured, thereby making it possible to ensure a lubricant flow between the communication section and the housing and to ensure a sufficient amount of lubricant supplied to the bearing section etc.
Specifically, as described above, in a case where the housing including the front housing and the rear housing is formed through casting, the inner face of the housing is provided with a draft angle tilting radially outward toward the opening. In this state, when the end face of the communication section is tilted at an angle close to the draft angle, the flow path between the communication section and the housing is prevented from being narrowed.
As a result, it is possible to ensure a lubricant flow between the communication section and the housing and to ensure a sufficient amount of lubricant supplied to the bearing section etc.
In the above-described invention, it is preferable that the communication section provided on at least one of the housing and the orbiting end plate be a groove that is made concave in a direction in which the drive shaft extends and that extends in a circumferential direction of the drive shaft.
According to this structure, for example, compared with the communication section that is concave in the radial direction, a surface of the orbiting end plate that is brought into contact with the fixed wall is easily ensured, and sufficient thickness of the side wall of the housing is easily ensured.
According to the scroll compressor of the present invention, an advantage is afforded in that, since the communication section is provided in the vicinity of the suction section, it is possible to always supply lubricant to parts requiring lubrication, such as the bearing section, and to improve the supply of lubricant to the sliding parts.
A scroll compressor according to a first embodiment of the present invention will be described below with reference to
In this embodiment, a description will be given of a case where a scroll compressor according to the present invention is used as a transverse scroll compressor used for vehicle air-conditioning apparatuses; however, it can be used for other air-conditioning apparatuses, and the purpose thereof is not particularly limited.
As shown in
Together with the rear housing 2R, the front housing 2F constitutes a closed container for accommodating the fixed scroll 3 and the orbiting scroll 4 and also forms the outer shape of the scroll compressor 1.
The front housing 2F is a member formed in a substantially cylindrical shape having a bottom, which is closed at the orbiting scroll 4 side, the orbiting scroll 4 to be described later, and is open at the fixed scroll 3 side. In other words, the front housing 2F is a member formed in a substantially cylindrical shape having a bottom, which is open at the end closer to the rear housing 2R and is closed at the other end.
As shown in
The suction section 22 is connected, for example, to an interior heat exchanger (not shown) of an air-conditioner that includes the scroll compressor 1 as a component, and refrigerant flows from the indoor heat exchanger into the suction section 22.
Furthermore, the suction section 22 is an opening provided on a cylindrical side wall of the front housing 2F and communicates with the suction chamber 21.
The suction chamber 21 is a cylindrical space formed between the front housing 2F, and the orbiting scroll 4 and the fixed scroll 3, and communicates with the outside via the suction section 22.
The suction chamber 21 also communicates with the supply flow paths 23 and communication sections 43.
The supply flow paths 23 communicate with a first bearing 24, to be described later, a lip seal section 25, the vicinities of a second bearing 55 and an eccentric bush 56, and the suction chamber 21.
As shown in
As shown in
The first bearing 24 supports the drive shaft 52 such that the drive shaft 52 can rotate about the central axis. Examples of the first bearing 24 include a ball bearing, and the type thereof is not particularly limited.
The lip seal section 25 separates the inside and the outside of the front housing 2F and the rear housing 2R; in other words, it ensures the sealing of the inside of the front housing 2F and the rear housing 2R.
Furthermore, the lip seal section 25 ensures the above-described sealing while allowing the drive shaft 52 to rotate about the central axis; in other words, it ensures the sealing while sliding over the rotating drive shaft 52.
Note that a known seal member can be used as the lip seal section 25, and the type thereof is not particularly limited.
As shown in
Note that a known mechanism can be used as the rotation-preventing mechanism 26, and the type thereof is not particularly limited.
Together with the front housing 2F, the rear housing 2R constitutes the closed container for accommodating the fixed scroll 3 and the orbiting scroll 4 and also forms the outer shape of the scroll compressor 1.
The rear housing 2R is formed in a lid-like shape for covering the opening of the front housing 2F, and the fixed scroll 3 is fixed in the rear housing 2R.
As shown in
The discharge section 28 is connected, for example, to an outdoor heat exchanger (not shown) of the air-conditioner that includes the scroll compressor 1 as a component, and refrigerant flows from the discharge section 28 into the outdoor heat exchanger.
Furthermore, the discharge section 28 is an opening provided in the rear housing 2R and communicates with the discharge chamber 27.
The discharge chamber 27 is a space formed between the rear housing 2R and the fixed scroll 3 and communicates with the outside via the discharge section 28.
The discharge chamber 27 also communicates with a discharge port 33, to be described later.
The fixed scroll 3 forms compression chambers C for compressing refrigerant, together with the orbiting scroll 4. The fixed scroll 3 is fixed to the rear housing 2R by using fixing members, such as bolts.
As shown in
The fixed end plate 31 constitutes the fixed scroll 3 together with the fixed wall 32 and is an approximately disc-like member fixed to the rear housing 2R.
As shown in
The discharge port 33 is a through-hole formed at substantially the center of the fixed end plate 31, in other words, in the vicinity of an inner end of the fixed wall 32.
A plate-like valve that controls opening and closing of the discharge port 33 is provided at an opening of the discharge port 33 closer to the discharge chamber 27. By controlling the opening and closing of the discharge port 33 is controlled with the valve, refrigerant always flows from the compression chambers C into the discharge chamber 27.
Furthermore, the fixed end plate 31 has a high face portion whose face is higher in an outward spiral direction, a low face portion whose face is lower in an inward spiral direction, and a semi-cylindrical end-plate step portion formed between the high face portion and the low face portion.
The fixed wall 32 constitutes the fixed scroll 3 together with the fixed end plate 31. The fixed wall 32 extends from the fixed end plate 31 toward the orbiting scroll 4 and is formed in a spiral shape defined based on an involute curve.
The tooth top of the fixed wall 32 has a low portion where the tooth height is lower in the outward spiral direction, a high portion where the tooth height is higher in the inward spiral direction, and a wall step portion formed between the low portion and the high portion.
The orbiting scroll 4 forms the compression chambers C for compressing refrigerant, together with the fixed scroll 3. The orbiting scroll 4 and the fixed scroll 3 are eccentric to each other by a predetermined distance and are engaged with a shift of 180 degrees, thereby forming the plurality of compression chambers C.
As shown in
The orbiting end plate 41 constitutes the orbiting scroll 4 together with the orbiting wall 42.
As shown in
As shown in
The communication sections 43 are formed when the end face of the orbiting end plate 41 facing the suction section 22 is formed in smooth sinusoidal shapes that are concave inward in the radial directions.
With this structure, for example, compared with a case where the communication sections 43 extend in a circumferential direction of the drive shaft 52, it is possible to make refrigerant and lubricant flow from the suction chamber 21 into the supply flow paths 23 without diverting them. Furthermore, since the communication sections 43 are formed as narrow areas, the communication sections 43 are easily formed.
As shown by a solid line in
Note that the end face of each communication section 43 may be formed as a face extending parallel to the drive shaft 52, as described above, or may be formed as a face tilting radially inward from the orbiting end plate 41 side toward the fixed end plate 31, in other words, as a tilted face extending substantially parallel to the inner circumferential face of the front housing 2F, as shown by a dashed line in
By doing so, sufficient flow-path cross-sectional area of the communication section 43 is ensured, thereby making it possible to ensure a lubricant flow between the communication section 43 and the front housing 2F and to ensure a sufficient amount of lubricant supplied to the first bearing 24, the second bearing 55, the lip seal section 25, etc.
Specifically, as described above, in a case where the front housing 2F is formed through casting, the inner face of the front housing 2F is provided with a draft angle tilting radially outward toward the opening. In this state, when the end face of the communication section 43 is tilted at an angle close to the draft angle, the flow path between the communication section 43 and the front housing 2F is prevented from being narrowed.
As a result, it is possible to ensure a lubricant flow between the communication section 43 and the front housing 2F and to ensure a sufficient amount of lubricant supplied to the first bearing 24, the second bearing 55, the lip seal section 25, etc.
Note that the communication section 43 may be formed in a sinusoidal-concave shape, as in the above-described embodiment, or may be formed in a concave shape having a depth smaller than a thickness T of the orbiting wall 42, as shown in
By setting a given limitation to the concave shape of the communication section 43, it is possible to prevent any influence on the formation of the compression chambers C, for compressing refrigerant, and to suppress deterioration in compression performance of the scroll compressor 1.
Specifically, the face of the orbiting end plate 41 facing the fixed scroll 3 is brought into contact with the fixed wall 32, slides thereon, and forms the compression chambers C for compressing refrigerant, together with the fixed scroll 3. Therefore, by limiting the depth of the concave shape of the communication sections 43 to be smaller than the thickness of the fixed wall 32, it is possible to separate the compression chambers C and the communication sections 43 even when the compression chambers C move closest to the communication sections 43.
As shown in
Furthermore, the orbiting end plate 41 has a high face portion whose face is higher in an outward spiral direction, a low face portion whose face is lower in an inward spiral direction, and a semi-cylindrical end-plate step portion formed between the high face portion and the low face portion.
The orbiting wall 42 constitutes the orbiting scroll 4 together with the orbiting end plate 41. The orbiting wall 42 extends from the orbiting end plate 41 toward the fixed scroll 3 and is formed in a spiral shape defined based on an involute curve.
The orbiting wall 42 has a low portion where the tooth height is lower in the outward spiral direction, a high portion where the tooth height is higher in the inward spiral direction, and a wall step portion formed between the low portion and the high portion.
The driving section 5 transfers a rotational driving force transferred from a vehicle engine (not shown) etc. to the orbiting scroll 4.
As shown in
The pulley section 51 is connected to the engine etc. via a drive belt, and a rotational driving force is transferred therefrom. The pulley section 51 further transfers the rotational driving force transferred from the engine etc. to the drive shaft 52.
Note that a known pulley can be used as the pulley section 51, and the type thereof is not particularly limited.
The drive shaft 52 transfers the rotational driving force transferred from the pulley section 51 to the orbiting scroll 4 and drives the orbiting scroll 4 in an orbital manner. The drive shaft 52 is supported rotatably about its axis by the first bearing 24 and the second bearing 55 provided on the front housing 2F.
As shown in
The large-diameter section 53 is a discoid-shaped or cylindrical-shaped part provided on an end portion of the drive shaft 52 closer to the orbiting scroll 4. The large-diameter section 53 is formed to have a larger diameter than the drive shaft 52 and has the driving pin 54 disposed on a face thereof facing the orbiting scroll 4.
As shown in
The second bearing 55 supports the drive shaft 52 such that the drive shaft 52 can rotate about the central axis. Examples of the second bearing 55 include a needle bearing, and the type thereof is not particularly limited.
The driving pin 54 is a cylindrical-shaped part provided on the face of the large-diameter section 53 facing the orbiting scroll 4 and drives the orbiting scroll 4 in an orbital manner, together with the eccentric bush 56 and the boss section 44.
The driving pin 54 is disposed at a position eccentric from the central axis of the drive shaft 52 by a predetermined distance. The predetermined distance is substantially the same as the eccentric distance between the fixed scroll 3 and the orbiting scroll 4.
As shown in
The eccentric bush 56 is disposed between the driving pin 54 and the boss section 44. Furthermore, the eccentric bush 56 is provided with a balance weight so as to compensate for a centrifugal force caused by the orbiting of the orbiting scroll 4.
A third bearing section 57 is provided between the eccentric bush 56 and the boss section 44.
The third bearing section 57 supports the eccentric bush 56 such that the eccentric bush 56 can rotate in the boss section 44. Examples of the third bearing section 57 include a needle bearing, and the type thereof is not particularly limited.
Next, compression of refrigerant in the scroll compressor 1, having the above-described structure, will be described.
In the scroll compressor 1, as shown in
When the orbiting scroll 4 is driven in an orbital manner, refrigerant enters the suction chamber 21 via the suction section 22 and is sucked into the compression chambers C formed between the orbiting scroll 4 and the fixed scroll 3. Then, through the orbital motion of the orbiting scroll 4, the compression chambers C reach the center portion while reducing the volumes to compress the refrigerant.
When the compression chambers C reach the center portion, the compressed refrigerant is discharged from the compression chambers C to the discharge chamber 27 via the discharge port 33. The refrigerant in the discharge chamber 27 is discharged to the outside of the scroll compressor 1 via the discharge section 28.
Next, circulation of lubricant contained in refrigerant, which is a feature of this embodiment, will be described.
Refrigerant containing lubricant, flowing from the suction section 22 into the suction chamber 21 flows from the suction chamber 21 into the supply flow paths 23. The refrigerant containing lubricant flowing through the supply flow paths 23 inward in the radial directions flows in the vicinities of the second bearing 55, the first bearing 24, and the lip seal section 25, thereby supplying lubricant to those parts.
As a result, the lubrication in the first bearing 24, the second bearing 55, and the lip seal section 25 is ensured.
In a state where the scroll compressor 1 is operated, specifically, in a state where the orbiting scroll 4 is driven in an orbital manner, most of the supply flow paths 23 are closed by the orbiting end plate 41 one time in one orbit of the orbiting scroll 4, as shown in
At this time, the communication sections 43 move to positions above the supply flow paths 23 and connect between the supply flow paths 23 and the suction chamber 21. Thus, the refrigerant containing lubricant flows from the suction chamber 21 into the supply flow paths 23 via the communication sections 43.
According to the above-described structure, since the communication sections 43 are provided, lubricant can always be supplied to parts requiring lubrication, such as the first bearing 24, the second bearing 55, and the lip seal section 25. Furthermore, it is possible to more reliably supply lubricant to the first bearing 24, the second bearing 55, the lip seal section 25, etc., by providing the communication sections 43 in the vicinities of the suction section 22, compared with a case where the communication sections 43 are provided in other portions.
In other words, it is possible to improve the supply of lubricant to sliding parts, such as the first bearing 24, the second bearing 55, and the lip seal section 25.
Specifically, with the communication sections 43 being provided, temporary blocking between the supply flow paths 23 and the suction chamber 21 is prevented when the orbiting scroll 4 orbits. Therefore, it is possible to always ensure the supply of lubricant to the first bearing 24, the second bearing 55, the lip seal section 25, etc. from the suction chamber 21 via the supply flow paths 23.
Furthermore, since the communication sections 43 are provided in the vicinities of the suction section 22, the momentum of refrigerant flowing into the suction chamber can be utilized to flow lubricant together with the refrigerant from the suction chamber 21 into the supply flow paths 23 and to supply the lubricant to the first bearing 24, the second bearing 55, the lip seal section 25, etc.
Note that the communication sections 43 may be formed in the orbiting end plate 41, as in the above-described embodiment, or groove-like communication sections 43A that continue from the supply flow paths 23 may be formed on the inner circumferential face of the front housing 2F, as shown in
Next, a second embodiment of the present invention will be described with reference to
The basic structure of a scroll compressor of this embodiment is the same as that of the first embodiment, but the position where a communication section is provided differs from that in the first embodiment. Therefore, in this embodiment, only a structure around the communication section will be described using
Note that identical reference symbols are assigned to the same components as those in the first embodiment, and a description thereof will be omitted.
As shown in
Next, circulation of lubricant contained in refrigerant, which is a feature of this embodiment, will be described.
In a state where the scroll compressor 101 is operated, in other words, where the orbiting scroll 4 is driven in an orbital manner, most of the supply flow paths 23 are closed by the orbiting end plate 41 one time in one orbit of the orbiting scroll 4, as shown in
At this time, the supply flow paths 23 and the suction chamber 21 are connected via the communication section 143 extending farther than the orbiting end plate 41, along the side wall of the front housing 2F. Therefore, refrigerant containing lubricant flows from the suction chamber 21 into the supply flow paths 23 via the communication section 143.
Note that, since a flow of refrigerant containing lubricant when the supply flow paths 23 are not closed by the orbiting end plate 41 is the same as that in the first embodiment, a description thereof will be omitted.
According to the above-described structure, for example, compared with the communication sections that are concave in the radial directions, a surface of the orbiting end plate 41 that is brought into contact with the fixed wall 32 is easily ensured. Furthermore, sufficient thickness of the side wall of the front housing 2F is easily ensured.
Note that the communication section 143 may be formed on the thrust surface 2S of the front housing 2F, as in the above-described embodiment, or a communication section 143A may be formed on a surface 41A of the orbiting end plate 41 facing the thrust surface 2S, as shown in
The communication section 143A is a step on the facing surface 41A, which is concave in a direction away from the thrust surface 2S outward in the radial direction, and is formed along the edge of the orbiting end plate 41 in an arc manner.
Number | Date | Country | Kind |
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2008-307372 | Dec 2008 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2009/070155 | 12/1/2009 | WO | 00 | 4/11/2011 |