The present invention relates to a variable capacity compressor lubricating a lubricated part by oil contained in refrigerant, and particularly, to a device adjusting an oil supply amount to the lubricated part.
In a variable capacity compressor used in a heat pump air-conditioning apparatus of a vehicle, a lubricated part such as a sliding part of the compressor, and the like is lubricated by supplying oil contained in refrigerant that is circulated in the compressor.
However, there is a case in which oil is excessively stored in a crank chamber in the compressor when the compressor is in operation. When oil is excessively stored in the crank chamber, there is no problem when a rotor in the crank chamber is at a low speed, but when the rotor is rotated at a high speed, oil is agitated at the high speed to generate friction heat by the agitation. Oil or the inside of the crank chamber becomes at a high temperature due to the friction heat and the entire compressor becomes at the high temperature. When the entire compressor becomes at the high temperature, durability of a member made of a resin or rubber deteriorates.
In view of the above, Patent Document 1 discloses a technology in which a storage chamber of oil is arranged outside the compressor by communicating with an inner space (crank chamber) of the compressor and centrifugal force that acts on oil is increased when a rotating member is rotated at the high speed to store excessive oil in the oil storage chamber, thereby suppressing friction heat.
Patent Document 1: Japanese Laid-Open Patent Application Publication No. 2009-150261
However, in the technology disclosed in Patent Document 1, when oil is stored in a storage chamber above an oil inflow passage, refrigerant closed in the storage chamber is pressurized, and as a result, the oil is difficult to flow in the storage chamber smoothly, and thus it is difficult to store a sufficient amount of oil in the storage chamber.
In view of the abovementioned the problems, an object of the present invention is to secure lubricating performance and durability of each member by adjusting an oil supply amount to a lubricated part to an appropriate amount according to a rotational speed of a rotating member in a variable capacity compressor.
In order to achieve the object, in a variable capacity compressor according to the present invention including a cylindrical receiving member, a rotating member rotated in a non-horizontal surface around a center shaft of the cylindrical receiving member, a plurality of pistons drawing and discharging refrigerant by reciprocating axially in parallel to a center shaft of the cylindrical receiving member in a plurality of cylinders formed on an outer periphery of the center shaft, a motion direction conversion mechanism converting a rotation motion of the rotating member into reciprocation of the piston, and a control mechanism controlling a refrigerant discharge amount by controlling a conversion amount of reciprocation of the piston to a rotation amount of the rotating member in the motion direction conversion mechanism, the compressor includes the following components.
An oil receiving unit receiving oil in the refrigerant on which centrifugal force acts is arranged outside a rotation trajectory of the rotating member while being positioned in an inner space receiving the rotating member of the cylindrical receiving member.
A plurality of communication holes is arranged, which includes a first communication hole that penetrates through the cylindrical receiving member and is close to the oil receiving unit at an upstream side in a rotational direction of the rotating member and a second communication hole spaced apart from the first communication hole in the rotational direction.
A storage chamber is arranged, which is formed outside the cylindrical receiving member to store the oil in the refrigerant so as to communicate with the inner space of the cylindrical receiving member through the plurality of communication holes.
In the inner space of the cylindrical receiving member, oil agitated with the refrigerant on which centrifugal force acts by being agitated with refrigerant by rotation of the rotating member is received by the oil receiving unit and the received oil flows into the storage chamber through the first communication hole adjacent thereto.
In this case, the refrigerant in an oil storage chamber is discharged to an inner space of the cylindrical receiving member through a communication hole positioned at an upper side among a plurality of communication holes, and as a result, pressing in the storage chamber is suppressed. Therefore, the oil flows into the storage chamber smoothly.
Furthermore, while an amount of oil that flows in (alternatively, to be flown in) from the first communication hole and an amount of oil that flows out (alternatively, to be flown out) from any one communication hole are balanced by a self-weight of the oil stored in the storage chamber, excessive oil may be stored in the storage chamber.
Herein, when the rotating member is rotated at a high speed, a lot of excessive oil is stored in the storage chamber to reduce an oil amount which is agitated by the rotating member, thereby securing lubricating performance and durability by suppressing generation of friction heat by the oil agitation.
Meanwhile, when the rotating member is rotated at a low speed, storing of oil in the storage chamber is suppressed due to a decrease in centrifugal force that acts on oil to increase the amount of oil that stores in an inner space of the cylindrical receiving member and excellent lubricating performance can be secured by increasing the amount of oil supplied to a lubricated part in the compressor.
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
A variable capacity compressor 100 used in an air-conditioning apparatus for a vehicle includes a cylinder block 101 having a plurality of (six in the embodiment) cylinders 101a on an outer periphery of a center shaft, a front housing 102 provided at one end of the cylinder block 101, and a rear housing 104 provided at the other end of the cylinder block 101 with a valve plate 103 interposed therebetween.
The front housing 102, the cylinder block 101, the valve plate 103, and the rear housing 104 constituting a cylindrical receiving member are joined to each other by a plurality of (six in the embodiment) penetration bolts 201 penetrating circumferential portions thereof.
A drive shaft 106 that crosses the inside of a crank chamber (an inner space of the cylindrical receiving member) 105 defined by the cylinder block 101 and the front housing 102 is provided and a swash plate 107 is disposed around the center thereof.
The swash plate 107 is coupled with a rotor 108 fixed to the drive shaft 106 through a connection unit 109, and as a result, an angle of inclination thereof is configured to be variable along the drive shaft 106. A coil spring 110 that urges force to the swash plate 107 toward a minimum inclination angle is mounted between the rotor 108 and the swash plate 107 and furthermore, a coil spring 111 that urges force to the swash plate 107 in a direction to increase the inclination angle is mounted on an opposite side with the swash plate 107 interposed therebetween.
One end of the drive shaft 106 extends to the outside by penetrating a boss portion 102a that protrudes to the outside of the front housing 102 and is connected to a pulley 131 engaged to a compressor driving belt of an engine (not illustrated) through an electromagnetic clutch 132 to be connectable and disconnectable.
A shaft seal device 112 is inserted between the drive shaft 106 and the boss portion 102a to block the inside and the outside of the compressor from each other.
A piston 117 is inserted into the cylinder 101a to be reciprocatable and an outer periphery of the swash plate 107 is received in one groove 117a disposed at the inside of the piston 117, and the piston 117 and the swash plate 107 are configured to interlock with each other with a pair of shoes 118 that slide to contact both surfaces of the outer periphery of the swash plate 107. Therefore, the piston 117 may reciprocate in the cylinder 101a by rotation of the drive shaft 106 and the series of members constitute a movement direction converting mechanism.
A suction chamber 119 and a discharge chamber 120 are compartmented in the rear housing 104, the suction chamber 119 communicates with the cylinder 101a through a communication hole 103a (suction hole) provided on the valve plate 103 and a suction valve (not illustrated), and the discharge chamber 120 communicates with the cylinder 101a through a discharge valve (not illustrated) and a communication hole 103b (discharge hole) provided on the valve plate 103.
The suction chamber 119 is connected with an air-conditioning apparatus system side through a suction port (not illustrated) and the discharge chamber 120 is connected with the air-conditioning apparatus system side through a discharge port (not illustrated).
A capacity control valve 200 is provided in the rear housing 104. The capacity control valve 200 controls an introduction amount of discharge gas into the crank chamber 105 by adjusting opening degree of air supply passages 121 (121a, 121b) that allow the discharge chamber 120 and the crank chamber 105 to communicate with each other. Furthermore, refrigerant in the crank chamber 105 flows into the suction chamber 119 through an air extraction passage which goes through a gap between the outer periphery of the drive shaft 106 and a bearing 115, a space 122, and a fixed orifice 103c of which an opening area is fixed, which is formed on the valve plate 103. Accordingly, the pressure of the crank chamber 105 is changed by adjusting an introduction amount of discharge gas into the crank chamber 105 by the capacity control valve 200 to control a discharge capacity.
In the variable capacity compressor 100 having the abovementioned basic structure, oil contained in refrigerant in the crank chamber 105 is stored at an appropriate amount according to an operating state (rotational speed), and as a result, a storage chamber that appropriately maintains the oil supply amount to the lubricated part in the compressor 100 is formed as described below.
As illustrated in
Furthermore, a second communication hole 203 is formed to penetrate through the circumference wall of the front housing 102 and be close to a penetration bolt 201b at a downstream side in the rotational direction. The penetration bolt 201b is positioned next above the penetration bolt 201a at the upstream side in the rotational direction.
In addition, the first communication hole 202 and the second communication hole 203 are formed around a front end portion of the front housing 102. As a result, in a maximum capacity, that is, even in a maximum stroke of the piston 117 in the case of a maximum inclination of the swash plate 107, the first communication hole 202 and the second communication hole 203 are formed at a portion at which oil in the refrigerant is in a high density without interfering with the piston 117.
Furthermore, a protruding wall 101b having the first communication hole 202 and the second communication hole 203 thereon, which surrounds the circumference wall of the front housing 102 in a rectangular shape is formed and an outer opening end of the protruding wall 101b abuts on a cover 204 to be sealed and four rectangular angled portions are joined by a bolt 205.
As a result, an oil storage chamber 206 is formed in an inner space surrounded by the circumference wall of the front housing 102, the protruding wall 101b, and the cover 204.
Next, an operation of the storage chamber 206 will be described.
The refrigerant in the crank chamber 105 is also rotated in the crank chamber 105 and the oil contained in the refrigerant receives rotational centrifugal force, by the rotation of the rotating member such as the rotor 108 according to the rotational speed of an engine or a motor which is a driving source of the variable compressor 100 and the swash plate 107 connected to the rotor 108.
The oil that receives the centrifugal force is received by contacting an upstream side of the penetration bolt 201 while being rotated along an outer peripheral side in the crank chamber 105, and particularly, the oil received from the penetration bolt 201a flows into the storage chamber 206 by passing through the first communication hole 202 which is formed to be close to the penetration bolt 201a at the upstream side in the rotational direction. As such, in the embodiment, a middle portion exposed into the crank chamber 105 of the penetration bolt 201a configures an oil receiving unit.
Furthermore, in the case in which the centrifugal force that acts on the oil is equal to or less than a predetermined value in the low rotational speed, when a liquid level of the oil that flows into the storage chamber 206 reaches the first communication hole 202, an inflow amount to the storage chamber 206 and an outflow amount from the storage chamber 206 are balanced, thereby suppressing storage of the oil in the storage chamber 206.
Meanwhile, when oil received from another penetration bolt 201 reaches a received amount corresponding to the centrifugal force, oil of an amount more than that drops or flows down along an inner wall of the front housing 102 due to its own weight to be stored on the bottom of the crank chamber 105.
In the low-speed rotation, the oil amount stored in the storage chamber 206 is small and most of the oil remains in the crank chamber 105, as described above.
At the low speed, as described above, since a tendency in which an oil film is broken in the rotating member such as the swash plate 107 which becomes the lubricated part or the sliding part such as the piston 117 is high, the oil amount required for lubrication is increased, but since a lot of oil remains in the crank chamber 105, a sufficient amount of oil is supplied to the lubricated part by sweeping up the oil by using the rotating member such as the swash plate 107, and as a result, excellent lubricating performance may be secured by preventing the oil film from being broken.
Furthermore, as the refrigerant containing the oil is agitated by rotating the rotating member such as the swash plate 107, the friction heat is generated, and since a heat generation amount is suppressed to be significantly low at the low speed, an influence by heat on the compressor may be disregarded.
When the rotational speed is increased, and as a result, the centrifugal force that acts on the oil is increased, oil that receives the increased centrifugal force contacts oil that receives through the upstream side of the penetration bolt 201a. Therefore, force to press the oil into the storage chamber 206 is increased. As a result, the inflow amount of the oil into the storage chamber 206 is increased, and as a result, the liquid level of the oil stored in the storage chamber 206 is raised higher than the first communication hole 202, while when a storage amount in the storage chamber 206 is increased, a liquid pressure by the self-weight of the oil is increased, and as a result, the discharge amount of the oil from the first communication hole 202 is also increased. Therefore, the liquid level is raised up to a part in which the inflow amount and the outflow amount are balanced.
As described above, as the rotational speed is high, the oil amount stored in the storage chamber 206 is increased.
At the high speed, the breakage tendency of the oil film of the sliding part is decreased, and as a result, the oil amount required for lubrication is decreased, while problem of heat generation by the agitation of the oil in the refrigerant appears. However, as the rotational speed is high, the oil amount agitated in the crank chamber 105 is decreased by increasing the oil amount stored in the storage chamber 206 to suppress heat generation, thereby suppressing deterioration in durability of each unit of the compressor by a thermal influence.
Furthermore, the oil may smoothly flow into the storage chamber 206 by a so called gas discharging function of discharging the refrigerant in the storage chamber 206 from the second communication hole 203 to the inside of the crank chamber 105 by the oil stored in the storage chamber 206. In particular, in the embodiment, since the second communication hole 203 is arranged to be close to the upper penetration bolt 201b at the downstream side in the rotational direction and negative pressure is generated at this position, a gas discharging operation of discharging the refrigerant in the storage chamber 206 to the crank chamber 105 is promoted, and as a result, the oil flows into the storage chamber 206 more smoothly.
After the oil is stored in the storage chamber 206 at the high-speed rotation as described above, when the rotational speed of the rotating member is decreased, the oil amount received through the penetration bolt 201a is decreased and pressing force to the storage chamber 206 is decreased, by the decrease in the centrifugal force received by the oil, and as a result, the oil in the storage chamber 206 is returned into the crank chamber 105 from the first communication hole 202 by the self-weight thereof.
As described in the first embodiment, the first communication hole 202 is arranged above a lowermost part of the crank chamber 105 and the storage chamber 206 is arranged on a lateral side of the crank chamber 105, and as a result, a storage amount of oil is easily secured, but the storage chamber may be arranged at an additional position.
Second and third embodiments illustrated in
Fourth to sixth embodiments illustrated in
Even in this case, the oil is received at the upstream side of the penetration bolt 201c to flow into the storage chamber 206 through the first communication hole 202 and in this case, the refrigerant in the storage chamber 206 is discharged into the crank chamber 105 through the second communication hole 203 arranged at a negative pressure generation side of a downstream of the penetration bolt 201c, and as a result, the oil may flow in smoothly.
In the above embodiment, the oil flows in from the first communication hole 202 at the lower side and gas is discharged from the second communication hole 203 at the upper side.
Contrary to this, in a seventh embodiment illustrated in
Even in this case, the seventh embodiment is the same as the first embodiment and
Meanwhile, the second communication hole 203 that is arranged below the storage chamber 206 serves to allow the oil that flows in and is stored in the storage chamber 206 from the first communication hole 202 to flow out. In addition, an opening area of the second communication hole 203 is formed to be small to have a throttling function, a storage amount in the storage chamber 206 is adjusted. In detail, as the rotational speed is increased, the oil inflow amount from the first communication hole 202 is increased and the storage amount to the storage chamber 206 is increased, but meanwhile, since the liquid pressure by the self-weight of the oil in the storage chamber 206 is also increased, the discharge amount of the oil from the second communication hole 203 is also increased, and as a result, the liquid level is raised up to the part in which the inflow amount and the outflow amount are balanced.
Herein, since the first communication hole 202 communicates at the upper side of the storage chamber 206, the first communication hole 202 is not closed with oil stored at the lower side. Therefore, when the first communication hole 202 has an opening area at a predetermined area or more, the first communication hole 202 may have a gas discharge function of discharging the refrigerant in the storage chamber 206 to the crank chamber 105 while the oil flows into the storage chamber 206, and as a result, the oil may smoothly flow into the storage chamber 206.
As such, the seventh embodiment is different from the first embodiment and the
Furthermore, as illustrated in
As illustrated above, the storage chambers 206 may be positioned at various locations around the crank chamber 105 and arranged at a location to avoid interference with other apparatuses such as an engine chamber in which the compressor 100 is arranged, and the like.
However, a location at the bottom is excluded because the oil is stored in the storage chamber at all times regardless of the high and low rotational speeds. It is necessary to exclude a location at the top because it is substantially difficult to store a sufficient amount of oil.
In the above embodiment, the joining penetration bolt is used as the oil receiving unit, but the oil receiving unit is provided separately from the penetration bolt, and as a result, an oil receiving function may be promoted.
By this configuration, the oil in the crank chamber 105 is more efficiently received to easily flow into the storage chamber 206 on the top of the oil receiving unit 301 connected to the first communication hole 202.
Moreover, the present invention may be applied to even the variable capacity compressor different from the variable capacity compressor applied to the embodiments in terms of some mechanisms.
For example, the variable capacity compressor disclosed in Japanese Examined Patent Application Publication No. H04-28911 includes a swash plate 401 and a piston 402 similarly as the above embodiment, as illustrated in
In the variable capacity compressor, since the guide plate 405 is arranged on an outer periphery of the rotating member such as the swash plate 401, the oil in the refrigerant is received by the guide plate 405 while contacting the guide plate 405. Accordingly, even when the receiving housing 404 which is separated axially and formed is joined by a means other than the penetration bolt, the present invention may be applied by using the guide plate 405 as the oil receiving unit.
In detail, as illustrated in
Furthermore, in the above embodiment, the inside of the storage chamber communicates with the suction chamber to the cylinder through negative pressure inflow passages such as a tube, a pipe, and the like, and a negative pressure of a suction chamber may be configured to be guided to the storage chamber, so that the oil easily flows into the storage chamber. In this case, the communication hole having the gas discharge function may be configured to communicate with the suction chamber.
Furthermore, the storage chamber 206 may extend axially up to the cylinder block 101 and furthermore, the rear housing 104 in addition to the front housing to thereby expand a storage capacity.
100 Variable capacity compressor
101 Cylinder block
101
a Cylinder
102 Front housing
103 Valve plate
104 Rear housing
105 Crank chamber
106 Drive shaft
107 Swash plate
108 Rotor
117 Piston
118 Shoe
119 Suction chamber
120 Discharge chamber
121 Air supply passage
200 Capacity control valve
201, 201a to 201e Penetration bolt
202 First communication hole
203 Second communication hole
204 Cover
205 Bolt
206 Storage chamber
301 Oil receiving unit
401 Swash plate
402 Piston
403 Swing plate
404 Receiving housing
405 Guide plate
406 Rod
407 First communication hole
408 Second communication hole
Number | Date | Country | Kind |
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2010-140145 | Jun 2010 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2011/062212 | 5/27/2011 | WO | 00 | 12/20/2012 |