Patent Application
20160069334
The present invention relates to a variable displacement swash plate type compressor.
A conventional variable displacement swash plate type compressor (hereinafter referred to as a compressor) is disclosed in Patent Literature 1. This compressor includes a suction chamber, a discharge chamber, a swash plate chamber, and plural cylinder bores, which are formed in a housing. A drive shaft is rotatably supported in the housing. The swash plate chamber accommodates a swash plate, which is rotatable along with rotation of the drive shaft. A link mechanism is provided between the drive shaft and swash plate. The link mechanism permits change of the inclination angle of the swash plate. The inclination angle is defined as an angle of the swash plate with respect to a direction perpendicular to the drive axis of the drive shaft. A piston is reciprocally accommodated in each of the cylinder bores. A pair of shoes provided for each piston serves as a conversion mechanism and reciprocates the piston in each of the cylinder bores along with rotation of the swash plate at a stroke corresponding to the inclination angle. An actuator is capable of changing the inclination angle by changing the volume of a control pressure chamber. The actuator is controlled by a control mechanism.
In this compressor, the control mechanism raises the pressure in the control pressure chamber by using the pressure of refrigerant in the discharge chamber and thereby increases the inclination angle of the swash plate via the link mechanism. At this time, when the link mechanism is pushed by the swash plate due to the pressure in the control pressure chamber and when the length of the link mechanism in an axial direction of the drive shaft is minimized, the inclination angle cannot be increased any further. In other words, in this compressor, the maximum inclination angle is restricted by pushing the link mechanism by the swash plate. In this way, in this compressor, discharge capacity per rotation of the drive shaft can be increased to the maximum.
In a compressor in which the inclination angle of the swash plate is changed by an actuator as described above, a required control pressure, which is the pressure in the control pressure chamber required to increase the inclination angle of the swash plate to the maximum value, is preset. If the compressor is configured such that a discharge refrigerant pressure, i.e. the pressure of refrigerant in the discharge chamber, is introduced to the control pressure chamber, the required control pressure is set lower than an upper limit of the discharge refrigerant pressure.
In the conventional compressor described above, since the maximum value of the inclination angle is restricted by pushing the link mechanism by the swash plate, a pressure in excess of the required control pressure is applied to the swash plate and the link mechanism. This makes it necessary to secure strength of the swash plate and the link mechanism of the compressor sufficiently to endure this pressure, and, as a result, it is inevitable to increase the size of the swash plate chamber and thus the size of the compressor.
Furthermore, in the conventional compressor described above, since the maximum value of the inclination angle is restricted by the link mechanism, which is formed by assembling plural parts in the axial direction of the drive shaft, dispersion in the maximum value of the inclination angle is likely to occur due to dimensional tolerance and the like of the swash plate and the link mechanism in the axial direction of the drive shaft. Thus, it is difficult to maintain the quality of each individual compressor.
The present invention has been made in view of the conventional circumstances described above, and an object of the invention is to provide a compressor, in which the inclination angle of a swash plate is changed by an actuator, ensuring excellent quality stability on a product-by-product basis while realizing reduction in size.
A variable displacement swash plate type compressor according to the present invention comprises: a housing in which a suction chamber, a discharge chamber, a swash plate chamber, and a cylinder bore are formed; a drive shaft extending along a drive axis and rotatably supported in the housing; a swash plate rotatable in the swash plate chamber along with rotation of the drive shaft; a link mechanism that is provided between the drive shaft and the swash plate and permits change of an inclination angle of the swash plate in a direction perpendicular to the drive axis of the drive shaft; a piston reciprocally accommodated in the cylinder bore; a conversion mechanism that reciprocates the piston in the cylinder bore along with rotation of the swash plate at a stroke corresponding to the inclination angle; an actuator capable of changing the inclination angle; and a control mechanism that controls the actuator,
wherein the suction chamber and the swash plate chamber communicate with each other,
the actuator includes a partition body provided on the drive shaft, a movable body that is movable along the drive axis of the drive shaft in the swash plate chamber and provided with a coupling portion to be coupled to the swash plate, and a control pressure chamber that is defined by the partition body and the movable body and moves the movable body by introducing a refrigerant from the discharge chamber, and
a maximum inclination restriction member that rotates synchronously with the drive shaft and restricts a maximum value of the inclination angle by abutting the movable body is provided on the drive shaft.
In the compressor according to the present invention, the required control pressure is also set lower than the upper limit of the discharge refrigerant pressure. In this compressor, the movable body of the actuator moves when the refrigerant is introduced into the control pressure chamber from the discharge chamber. Thereby, the inclination angle of the swash plate changes in this compressor. In the compressor, the maximum value of the inclination angle of the swash plate is restricted as the movable body abuts the maximum inclination restriction member. That is, in this compressor, although the movable body and the swash plate are coupled to each other via the coupling portion, the swash plate does not push the link mechanism using the pressure in the control pressure chamber in order to restrict the maximum value of the inclination angle. Consequently, in this compressor, pressure in excess of the required control pressure does not act on the swash plate and the link mechanism, and therefore, it is not necessary to ensure the strength of the swash plate and the link mechanism more than required. Thus, the compressor eliminates the need to upsize the swash plate chamber.
Also, in the compressor, the maximum value of the inclination angle is restricted by having the movable body abut the maximum inclination restriction member rather than by use of the link mechanism. Consequently, even if the swash plate and the link mechanism have dimensional tolerance and the like in the axial direction of the drive shaft, such tolerance does not cause dispersion in the maximum value of the inclination angle.
Furthermore, since the maximum inclination restriction member rotates synchronously with the drive shaft, even when the movable body abuts the maximum inclination restriction member, rotation of the movable body and the swash plate is not restricted by the maximum inclination restriction member.
Thus, the compressor according to the present invention, in which the inclination angle of the swash plate is changed by the actuator, ensures excellent quality stability on a product-by-product basis while realizing reduction in size.
In the compressor according to the present invention, various members may be employed as the maximum inclination restriction member as long as the members have sufficient strength to endure pressure in excess of the required control pressure and are rotatable synchronously with the drive shaft. Furthermore, for example, a protrusion or the like may be formed on the movable body exclusively for the purpose of abutting the maximum inclination restriction member.
In the compressor according to the present invention, the drive shaft may include a drive shaft body and a cap that is press-fitted to the drive shaft body and located in the swash plate chamber. It is preferable that the cap is the maximum inclination restriction member. In this case, by having the movable body abut the cap, it is possible to restrict the maximum value of the inclination angle. Furthermore, when the cap is the maximum inclination restriction member, it is possible to adjust a position where the movable body abuts the cap depending on the shape of the cap and the position where the cap is press-fitted to the drive shaft body. Thus, the compressor is able to suitably restrict the maximum value of the inclination angle.
The compressor according to the present invention may comprise a circlip that is fitted to the drive shaft and located in the swash plate chamber. It is also preferable that the circlip is the maximum inclination restriction member. Also in this case, it is possible to adjust a position where the movable body abuts the circlip depending on the position where the circlip is fitted to the drive shaft body. Thus, this compressor is also able to suitably restrict the maximum value of the inclination angle.
The compressor according to the present invention, in which the inclination angle of the swash plate is changed by the actuator, ensures excellent quality stability on a product-by-product basis while realizing reduction in size.
Embodiments 1 and 2, which embody the present invention, will be described below with reference to the drawings. The compressors according to Embodiments 1 and 2 are variable displacement double head swash plate type compressors. These compressors are both mounted on vehicles and constitute refrigeration circuits of vehicle air-conditioning apparatus.
As shown in
As shown in
A boss 17a, which protrudes frontward, is formed in the front housing 17. A shaft seal device 25 is provided in the boss 17a. A first suction chamber 27a and a first discharge chamber 29a are formed in the front housing 17. The first suction chamber 27a is located on an inner peripheral side in the front housing 17. The first discharge chamber 29a is formed into an annular shape and located on an outer peripheral side of the first suction chamber 27a in the front housing 17.
A first front-side communication passage 18a is formed in the front housing 17. The front end of the first front-side communication passage 18a communicates with the first discharge chamber 29a, and the rear end thereof opens at the rear end of the front housing 17.
The control mechanism 15 described above is provided in the rear housing 19. Also, a second suction chamber 27b, a second discharge chamber 29b, and a pressure regulation chamber 31 are formed in the rear housing 19. The pressure regulation chamber 31 is located in the central part of the rear housing 19. The second suction chamber 27b is formed into an annular shape and located on an outer peripheral side of the pressure regulation chamber 31 in the rear housing 19. The second discharge chamber 29b is also formed into an annular shape and located on an outer peripheral side of the second suction chamber 27b in the rear housing 19.
A first rear-side communication passage 20a is formed in the rear housing 19. The rear end of the first rear-side communication passage 20a communicates with the second discharge chamber 29b, and the front end thereof opens at the front end of the rear housing 19.
A swash plate chamber 33 is formed between the first cylinder block 21 and the second cylinder block 23. The swash plate chamber 33 is located at an approximate center in the front-rear direction of the housing 1.
Plural first cylinder bores 21a are formed parallel to one another at equal angular intervals in a circumferential direction in the first cylinder block 21. Also, a first shaft hole 21b is formed in the first cylinder block 21 to allow the drive shaft 3 to be inserted therethrough. A first sliding bearing 22a is provided on the first shaft hole 21b. A roller bearing may be provided instead of the first sliding bearing 22a.
The first cylinder block 21 has a first recess 21c, which communicates with the first shaft hole 21b and is coaxial with the first shaft hole 21b. The first recess 21c communicates with the swash plate chamber 33 and forms part of the swash plate chamber 33. The first recess 21c is shaped such that its diameter becomes smaller toward the front end in a stepwise manner. A first thrust bearing 35a is provided on a front end of the first recess 21c. A first connecting passage 37a is formed in the first cylinder block 21 to allow the swash plate chamber 33 to communicate with the first suction chamber 27a. Also, a first retainer groove 21e is provided in the first cylinder block 21 to restrict a maximum opening degree of respective first suction reed valves 391a described later.
A second front-side communication passage 18b is formed in the first cylinder block 21. The front end of the second front-side communication passage 18b opens at the front end of the first cylinder block 21, and the rear end thereof opens at the rear end of the first cylinder block 21.
Similarly to the first cylinder block 21, plural second cylinder bores 23a are formed in the second cylinder block 23. The second cylinder bores 23a are respectively paired with the first cylinder bores 21a in the front-rear direction. The first cylinder bores 21a and the second cylinder bores 23a are equal in diameter.
Also, a second shaft hole 23b is formed in the second cylinder block 23 to allow the drive shaft 3 to be inserted therethrough. The rear end of the second shaft hole 23b communicates with the pressure regulation chamber 31. A second sliding bearing 22b is provided on the second shaft hole 23b. A roller bearing may be provided instead of the second sliding bearing 22b.
The second cylinder block 23 has a second recess 23c, which communicates with the second shaft hole 23b and is coaxial with the second shaft hole 23b. The second recess 23c also communicates with the swash plate chamber 33 and forms part of the swash plate chamber 33. Accordingly, the front end of the second shaft hole 23b communicates with the swash plate chamber 33. The second recess 23c is shaped such that its diameter becomes smaller toward the rear end in a stepwise manner. A second thrust bearing 35b is provided on the rear end of the second recess 23c. A second connecting passage 37b is formed in the second cylinder block 23 to allow the swash plate chamber 33 to communicate with the second suction chamber 27b. Also, a second retainer groove 23e is provided in the second cylinder block 23 to restrict a maximum opening degree of second suction reed valves 411a described later.
The second cylinder block 23 includes an outlet port 230, a confluence discharge chamber 231, a third front-side communication passage 18c, a second rear-side communication passage 20b, and an inlet port 330. The outlet port 230 and the confluence discharge chamber 231 communicate with each other. Via the outlet port 230, the confluence discharge chamber 231 is connected to a condenser (not shown) making up a refrigeration circuit.
The front end of the third front-side communication passage 18c opens to the front end of the second cylinder block 23, and the rear end thereof communicates with the confluence discharge chamber 231. The third front-side communication passage 18c communicates with the rear end of the second front-side communication passage 18b when the first cylinder block 21 and the second cylinder block 23 are joined together.
The front end of the second rear-side communication passage 20b communicates with the confluence discharge chamber 231, and the rear end thereof opens to the rear end of the second cylinder block 23.
The inlet port 330 is formed in the second cylinder block 23. Via the inlet port 330, the swash plate chamber 33 is connected to an evaporator (not shown) making up the refrigeration circuit.
The first valve forming plate 39 is provided between the front housing 17 and the first cylinder block 21. Also, the second valve forming plate 41 is provided between the rear housing 19 and the second cylinder block 23.
The first valve forming plate 39 includes a first valve plate 390, a first suction valve plate 391, a first discharge valve plate 392, and a first retainer plate 393. First suction ports 390a, the number of which is equal to the number of the first cylinder bores 21a, are formed in the first valve plate 390, the first discharge valve plate 392, and the first retainer plate 393. First discharge ports 390b, the number of which is equal to the number of the first cylinder bores 21a, are formed in the first valve plate 390 and the first suction valve plate 391. A first suction communication hole 390c is formed in the first valve plate 390, the first suction valve plate 391, the first discharge valve plate 392, and the first retainer plate 393. A first discharge communication hole 390d is formed in the first valve plate 390 and the first suction valve plate 391.
The first cylinder bores 21a communicate with the first suction chamber 27a through the respective first suction ports 390a. Also, the first cylinder bores 21a communicate with the first discharge chamber 29a through the respective first discharge ports 390b. The first suction chamber 27a communicates with the first connecting passages 37a through the first suction communication hole 390c. The first front-side communication passage 18a communicates with the second front-side communication passage 18b through the first discharge communication hole 390d.
The first suction valve plate 391 is provided on the rear face of the first valve plate 390. The first suction valve plate 391 has the plural first suction reed valves 391a which are capable of opening and closing the respective first suction ports 390a by elastic deformation. The first discharge valve plate 392 is provided on the front face of the first valve plate 390. The first discharge valve plate 392 has plural first discharge reed valves 392a which are capable of opening and closing the respective first discharge ports 390b by elastic deformation. The first retainer plate 393 is provided on the front face of the first discharge valve plate 392. The first retainer plate 393 restricts a maximum opening degree of the respective first discharge reed valves 392a.
The second valve forming plate 41 includes a second valve plate 410, a second suction valve plate 411, a second discharge valve plate 412, and a second retainer plate 413. Second suction ports 410a, the number of which is equal to the number of the second cylinder bores 23a, are formed in the second valve plate 410, the second discharge valve plate 412, and the second retainer plate 413. Second discharge ports 410b, the number of which is equal to the number of the second cylinder bores 23a, are formed in the second valve plate 410 and the second suction valve plate 411. A second suction communication hole 410c is formed in the second valve plate 410, the second suction valve plate 411, the second discharge valve plate 412, and the second retainer plate 413. A second discharge communication hole 410d is formed in the second valve plate 410 and the second suction valve plate 411.
The second cylinder bores 23a communicate with the second suction chamber 27b through the respective second suction ports 410a. Also, the second cylinder bores 23a communicate with the second discharge chamber 29b through the respective second discharge ports 410b. The second suction chamber 27b communicates with the second connecting passages 37b through the second suction communication hole 410c. The first rear-side communication passage 20a communicates with the second rear-side communication passage 20b through the second discharge communication hole 410d.
The second suction valve plate 411 is provided on the front face of the second valve plate 410. The second suction valve plate 411 is provided with the plural second suction reed valves 411a which are capable of opening and closing the respective second suction ports 410a by elastic deformation. Also, the second discharge valve plate 412 is provided on the rear face of the second valve plate 410. The second discharge valve plate 412 is provided with plural second discharge reed valves 412a which are capable of opening and closing the respective second discharge ports 410b by elastic deformation. The second retainer plate 413 is provided on the rear face of the second discharge valve plate 412. The second retainer plate 413 restricts a maximum opening degree of each of the second discharge reed valves 412a.
In the compressor, a first discharge communication passage 18 is formed by the first front-side communication passage 18a, the first discharge communication hole 390d, the second front-side communication passage 18b, and the third front-side communication passage 18c. Also, a second discharge communication passage 20 is formed by the first rear-side communication passage 20a, the second discharge communication hole 410d, and the second rear-side communication passage 20b.
Also, in the compressor, the first and second suction chambers 27a and 27b and the swash plate chamber 33 communicate with each other via the first and second connecting passages 37a and 37b and the first and second suction communication holes 390c and 410c. Consequently, the pressure in the first and second suction chambers 27a and 27b and the swash plate chamber 33 are substantially equal. Because a low-pressure refrigerant gas which has passed through an evaporator flows into the swash plate chamber 33 through the inlet port 330, the pressure in the swash plate chamber 33 and the first and second suction chambers 27a and 27b is lower than the pressure in the first and second discharge chambers 29a and 29b.
The drive shaft 3 is made up of a drive shaft body 30 extending along a drive axis O, a first support member 43a, and a second support member 43b. A first small-diameter portion 30a is formed on the front end side of the drive shaft body 30, and a second small-diameter portion 30b is formed on the rear end side of the drive shaft body 30. The drive shaft body 30 extends rearward from the front side of the housing 1 by being inserted rearward from the boss 17a through the first and second sliding bearings 22a and 22b. Consequently, the drive shaft body 30 and thus the drive shaft 3 are supported by the housing 1 so as to be rotatable around [[a] ] the drive axis O. The front end of the drive shaft body 30 is located in the boss 17a and the rear end thereof protrudes into the pressure regulation chamber 31.
The swash plate 5, the link mechanism 7, and the actuator 13 are provided on the drive shaft body 30. The swash plate 5, the link mechanism 7, and the actuator 13 are all disposed in the swash plate chamber 33.
The first support member 43a is press-fitted to the first small-diameter portion 30a of the drive shaft body 30 and located inside of the first sliding bearing 22a in the first shaft hole 21b. Also, the first support member 43a includes a flange 430 configured to abut the first thrust bearing 35a, and a mounting portion (not shown) configured to allow a second pin 47b, which will be described later, to be inserted therethrough. A front end of a first return spring 44a is fixed to the first support member 43a. The first return spring 44a extends from the first support member 43a toward the swash plate chamber 33 along the drive axis O.
The second support member 43b is press-fitted to the rear end of the second small-diameter portion 30b of the drive shaft body 30, and is located in the second shaft hole 23b. The second support member 43b corresponds to a cap according to the present invention. A flange 431 is formed on the front end of the second support member 43b. The flange 431 has a flat-shaped front face 431a. The flange 431 protrudes into the second recess 23c and abuts the second thrust bearing 35b. Also, the rear end of the second support member 43b protrudes into the pressure regulation chamber 31. In the second support member 43b, a first slide member 432 and a second slide member 433 made of resin are provided in the rear of the flange 431. The first and second slide members 432 and 433 are in contact with and slidable along an inner circumferential surface of the second shaft hole 23b.
The second sliding bearing 22b is press-fitted into the rear end of the second shaft hole 23b. Thereby, the second sliding bearing 22b is provided in the second shaft hole 23b.
The swash plate 5 has a flat annular shape and includes a front face 5a and a rear face 5b. The front face 5a faces frontward of the compressor in the swash plate chamber 33. Also, the rear face 5b faces rearward of the compressor in the swash plate chamber 33.
The swash plate 5 is fixed to a ring plate 45. The ring plate 45 has a flat annular shape with an insertion hole 45a formed in the center. The swash plate 5 is attached to the drive shaft 3 by inserting the drive shaft body 30 through the insertion hole 45a in the swash plate chamber 33.
The link mechanism 7 has a lug arm 49. In the swash plate chamber 33, the lug arm 49 is placed frontward relative to the swash plate 5 and located between the swash plate 5 and the first support member 43a. The lug arm 49 is formed so as to be substantially L-shaped from the front end toward the rear end. As shown in
As shown in
The front end of the lug arm 49 is connected to the first support member 43a via the second pin 47b. When the axis of the second pin 47b is defined as a second pivot axis M2, the front end of the lug arm 49 is supported around the second pivot axis M2 so as to be pivotable with respect to the first support member 43a, i.e., the drive shaft 3. The second pivot axis M2 extends parallel to the first pivot axis M1. The link mechanism 7 according to the present invention is made up of the lug arm 49, the first and second pins 47a and 47b, and, in addition, first and second pulling arms 132 and 133 and a third pin 47c, which will be described later.
The weight 49a is provided so as to extend at the rear end of the lug arm 49, i.e., on the opposite side of the second pivot axis M2 with reference to the first pivot axis M1. As the lug arm 49 is supported by the ring plate 45 with the first pin 47a, the weight 49a passes through a groove 45b in the ring plate 45 and reaches the rear face side of the ring plate 45, i.e., the side of the rear face 5b of the swash plate 5. Therefore, a centrifugal force produced by rotation of the swash plate 5 around the drive axis O also acts on the weight 49a at the side of the rear face 5b of the swash plate 5.
In this compressor, the swash plate 5 is able to rotate together with the drive shaft 3 as the swash plate 5 is connected to the drive shaft 3 by the link mechanism 7. Also, the swash plate 5 is able to change its inclination angle due to the pivotal movement of both ends of the lug arm 49 around the first pivot axis M1 and the second pivot axis M2, respectively.
The pistons 9 each has a first head 9a at its front end and a second head 9b at its rear end. The first head 9a is reciprocally accommodated in each of the first cylinder bores 21a. The first head 9a and the first valve forming plate 39 define a first compression chamber 21d in each of the first cylinder bores 21a. The second head 9b is reciprocally accommodated in each of the second cylinder bores 23a. The second head 9b and the second valve forming plate 41 define a second compression chamber 23d in each of the second cylinder bores 23a.
An engaging portion 9c is formed in the middle of each of the pistons 9. Hemispherical shoes 11a and 11b are provided in each of the engaging portions 9c. The shoes 11a and 11b convert rotation of the swash plate 5 into reciprocating movement of the pistons 9. The shoes 11a and 11b correspond to a conversion mechanism according to the present invention. Thereby, the first and second heads 9a, 9b are able to reciprocate in the first and second cylinder bores 21a, 23a at a stroke corresponding to the inclination angle of the swash plate 5.
Here, in the compressor, when the stroke of the pistons 9 changes according to the change in the inclination angle of the swash plate 5, respective top dead center positions of the first heads 9a and the second heads 9b move. Specifically, as the inclination angle of the swash plate 5 decreases, the top dead center positions of the first and second heads 9a and 9b move such that the volume of the second compression chamber 23d becomes larger than the volume of the first compression chamber 21d.
As shown in
As shown in
Both of the first pulling arm 132 and the second pulling arm 133 are formed at the front end of the circumferential wall 131. The first pulling arm 132 and second pulling arm 133 of the circumferential wall 131 are placed so as to face each other across the drive axis O and protrude frontward in the movable body 13a. These first and second pulling arms 132 and 133 correspond to a coupling portion according to the present invention. A first pin hole 132a and a second pin hole 133a are bored through the first pulling arm 132 and the second pulling arm 133, respectively. The movable body 13a is formed into a bottomed cylindrical shape by the rear wall 130, the circumferential wall 131, and the first and second pulling arms 132 and 133.
As shown in
The second small-diameter portion 30b of the drive shaft body 30 is inserted through the movable body 13a and the partition body 13b. The movable body 13a is accommodated in the second recess 23c and faces the link mechanism 7 across the swash plate 5. The partition body 13b is placed in the movable body 13a at a position rearward of the swash plate 5, and its periphery is surrounded by the circumferential wall 131. Consequently, the control pressure chamber 13c is formed between the movable body 13a and the partition body 13b. The control pressure chamber 13c is separated from the swash plate chamber 33 by the rear wall 130 and the circumferential wall 131 of the movable body 13a and the partition body 13b.
In the compressor, a required control pressure, which is the pressure in the control pressure chamber 13c required to increase the inclination angle of the swash plate 5 to a maximum value, is preset to the control pressure chamber 13c. The required control pressure is set lower than the upper limit of the discharge refrigerant pressure, i.e., the upper limit of the pressure of refrigerant gas in the first discharge chamber 29a and the second discharge chamber 29b.
In the compressor, due to the insertion of the second small-diameter portion 30b, the movable body 13a is able to rotate together with the drive shaft 3 and move along the drive axis O of the drive shaft 3 in the swash plate chamber 33. On the other hand, the partition body 13b is fixed to the second small-diameter portion 30b in the state that the second small-diameter portion 30b has been inserted therethrough. The partition body 13b is thus only able to rotate together with the drive shaft 3, and not able to move in the same manner as the movable body 13a. As a result, the movable body 13a moves along the drive axis O relative to the partition body 13b. The partition body 13b may be provided on the drive shaft body 30 so as to be movable along the drive axis O.
The first and second pulling arms 132 and 133 are connected with the opposite end side of the ring plate 45 by the third pin 47c. The third pin 47c extends from the first pin hole 132a, which is shown in
The second small-diameter portion 30b has an axial path 3a, which extends frontward from the rear end along the drive axis O, and a radial path 3b, which extends in a radial direction from the front end of the axial path 3a and opens in an outer circumferential surface of the drive shaft body 30. The rear end of the axial path 3a opens to the pressure regulation chamber 31. The radial path 3b opens to the control pressure chamber 13c. The control pressure chamber 13c thus communicates with the pressure regulation chamber 31 through the radial path 3b and the axial path 3a.
A threaded portion 3d is formed on a tip end of the drive shaft body 30. Via the threaded portion 3d, the drive shaft 3 is connected to a pulley or an electro-magnetic clutch (not shown).
As shown in
The low-pressure passage 15a is connected to the pressure regulation chamber 31 and the second suction chamber 27b. Through the low-pressure passage 15a, the axial path 3a, and the radial path 3b, the control pressure chamber 13c, the pressure regulation chamber 31, and the second suction chamber 27b communicate with one another. The high-pressure passage 15b is connected to the pressure regulation chamber 31 and the second discharge chamber 29b. Through the high-pressure passage 15b, the axial path 3a, and the radial path 3b, the control pressure chamber 13c, the pressure regulation chamber 31, and the second discharge chamber 29b communicate with one another. The orifice 15d is provided in the high-pressure passage 15b.
The control valve 15c is provided on the low-pressure passage 15a. The control valve 15c is able to adjust an opening degree of the low-pressure passage 15a based on the pressure in the second suction chamber 27b.
In the compressor, the inlet port 330 shown in
In the compressor configured as described above, by rotation of the drive shaft 3, the swash plate 5 rotates and the pistons 9 reciprocate in the first and second cylinder bores 21a and 23a. Thereby, the first and second compression chambers 21d and 23d change their volumes according to the piston stroke. In the compressor, a suction phase for sucking refrigerant gas into the first and second compression chambers 21d and 23d, a compression phase for compressing the refrigerant gas in the first and second compression chambers 21d and 23d, and a discharge phase for discharging the compressed refrigerant gas into the first and second discharge chambers 29a and 29b take place repeatedly.
The refrigerant gas discharged into the first discharge chamber 29a passes through the first discharge communication passage 18 and reaches the confluence discharge chamber 231. Similarly, the refrigerant gas discharged into the second discharge chamber 29b passes through the second discharge communication passage 20 and reaches the confluence discharge chamber 231. After reaching the confluence discharge chamber 231, the refrigerant gas is discharged to the condenser through the outlet port 230.
While these suction phase and so forth take place, a piston compression force to reduce the inclination angle of the swash plate 5 is applied to a rotational body, which is made up of the swash plate 5, the ring plate 45, the lug arm 49, and the first pin 47a. When the inclination angle of the swash plate 5 is changed, the stroke of the pistons 9 increases or decreases, and thereby, it is possible to control the displacement.
Specifically, when the control valve 15c, which is shown in
Consequently, in the compressor, the movable body 13a pushes the swash plate 5 at the opposite end side frontward in the swash plate chamber 33 at the action axis M3 via the first and second pulling arms 132 and 133. Thus, in the compressor, the opposite end side of the ring plate 45, in other words, the opposite end side of the swash plate 5, pivots clockwise around the action axis M3 against a biasing force of the second return spring 44b. Also, the rear end of the lug arm 49 pivots counterclockwise around the first pivot axis M1 and the front end of the lug arm 49 pivots counterclockwise around the second pivot axis M2. The lug arm 49 comes close to the flange 430 of the first support member 43a. Thereby, the swash plate 5 pivots using the action axis M3 as a point of action and using the first pivot axis M1 as a fulcrum. This reduces the inclination angle of the swash plate 5 with respect to the direction perpendicular to the drive axis O of the drive shaft 3 and decreases the stroke of the pistons 9. Therefore, discharge capacity of the compressor per rotation of the drive shaft 3 decreases. The inclination angle of the swash plate 5 shown in
Here, in this compressor, the centrifugal force acting on the weight 49a is also applied to the swash plate 5. Thus, the swash plate 5 of this compressor is easily displaced toward a direction of reducing the inclination angle.
When the inclination angle of the swash plate 5 decreases, the ring plate 45 abuts the rear end of the first return spring 44a. The first return spring 44a thus deforms elastically and the rear end of the first return spring 44a comes close to the first support member 43a.
In this compressor, as the inclination angle of the swash plate 5 becomes smaller and the stroke of the pistons 9 decreases, the top dead center position of the second heads 9b moves away from the second valve forming plate 41. Thus, in the compressor, when the inclination angle of the swash plate 5 approaches 0 degrees, compression work is performed slightly in the first compression chamber 21d, whereas compression work is not performed in the second compression chamber 23d.
When the control valve 15c shown in
Consequently, in the compressor, the movable body 13a pulls the opposite end side of the swash plate 5 rearward in the swash plate chamber 33 at the action axis M3 via the first and second pulling arms 132 and 133. Thus, in the compressor, the opposite end side of the swash plate 5 pivots counterclockwise around the action axis M3. Also, the rear side of the lug arm 49 pivots clockwise around the first pivot axis M1 and the front end of the lug arm 49 pivots clockwise around the second pivot axis M2. The lug arm 49 moves away from the flange 430 of the first support member 43a. Thereby, the swash plate 5 pivots in a direction opposite to the above-described direction in the case of reducing the inclination angle, using the action axis M3 as a point of action and using the first pivot axis M1 as a fulcrum. This increases the inclination angle of the swash plate 5 with respect to the direction perpendicular to the drive axis O of the drive shaft 3.
Here, in the compressor, the movable body 13a moves towards the flange 431 and pulls the opposite end side of the swash plate 5 rearward in the swash plate chamber 33 via the first and second pulling arms 132 and 133 until the pressure in the control pressure chamber 13c reaches the required control pressure. Thus, the link mechanism 7 permits increase of the inclination angle of the swash plate 5 until it reaches the maximum value. The discharge capacity of the compressor per rotation of the drive shaft 3 increases as the stroke of the pistons 9 increases. When the pressure in the control pressure chamber 13c reaches the required control pressure, the inclination angle of the swash plate 5 reaches the maximum value as shown in
In the compressor, while the required control pressure of the control pressure chamber 13c is set lower than the upper limit of the discharge refrigerant pressure as described above, the refrigerant gas is introduced into the control pressure chamber 13c from the second discharge chamber 29b through the high-pressure passage 15b and the like. Therefore, in the compressor, even after the inclination angle of the swash plate 5 reaches the maximum value as described above, the pressure in the control pressure chamber 13c continues to increase beyond the required control pressure.
In this regard, in the compressor, when the pressure in the control pressure chamber 13c increases and reaches the required control pressure, the movable body 13a moves rearward in the swash plate chamber 33 and the rear wall 130 abuts the front face 431a of the flange 431. This allows the compressor to restrict the maximum value of the inclination angle of the swash plate 5. That is, in this compressor, although the movable body 13a and the swash plate 5 are coupled to each other via the first and second pulling arms 132 and 133, for restricting the maximum value of the inclination angle, the swash plate 5 does not push the lug arm 49 of the link mechanism 7 due to the pressure in the control pressure chamber 13c. In this compressor, the pressure in excess of the required control pressure acts on the flange 431 and thus on the second support member 43b, but does not act on the swash plate 5 or the lug arm 49 of the link mechanism 7 via the first and second pulling arms 132 and 133. Therefore, it is not necessary in this compressor to ensure the strength of the swash plate 5 and the lug arm 49 more than required. Thus, the compressor eliminates the need to upsize the swash plate chamber 33.
In the compressor, the maximum value of the inclination angle is restricted by the rear wall 130 of the movable body 13a and the flange 431 abutting each other, not by the link mechanism 7. Therefore, in the compressor, even if the swash plate 5 and the link mechanism 7 have dimensional tolerance and the like in the direction of the drive axis O, such tolerance does not cause dispersion in the maximum value of the inclination angle.
In the compressor, since the second support member 43b is press-fitted to the drive shaft body 30, the second support member 43b including the flange 431 rotates synchronously with the drive shaft body 30. Therefore, in the compressor, even when the rear wall 130 abuts the flange 431, the rotation of the movable body 13a and even the swash plate 5 is not restricted by the flange 431.
Therefore, the compressor according to Embodiment 1, in which the inclination angle of the swash plate 5 is changed by the actuator 13, ensures excellent quality stability on a product-by-product basis while realizing reduction in size.
In particular, in this compressor, the maximum value of the inclination angle is restricted by having the flange 431 of the second support member 43b abut the rear wall 130 of the movable body 13a. Therefore, in this compressor, it is possible to adjust the position where the rear wall 130 abuts the flange 431 depending on the thickness of the flange 431 and the shape of the second support member 43b by itself. Furthermore, in this compressor, it is also possible to adjust the position where the rear wall 130 abuts the flange 431 depending on the position where the second support member 43b is press-fitted to the second small-diameter portion 30b of the drive shaft body 30. Thus, the compressor is capable of suitably restricting the maximum value of the inclination angle.
In the compressor according to Embodiment 2, as shown in
In this compressor, when the pressure in the control pressure chamber 13c increases and reaches the required control pressure, the rear wall 130 of the movable body 13a which has moved rearward in the swash plate chamber 33 abuts the circlip 51. This allows the compressor to restrict the maximum value of the inclination angle of the swash plate 5 without having the swash plate 5 push the link mechanism 7.
Also, in the compressor, it is possible to adjust the position at which the rear wall 130 abuts the circlip 51 depending on the position where the circlip 51 is press-fitted to the second small-diameter portion 30b. Thus, the maximum value of the inclination angle can be suitably restricted in this compressor. The other operations of this compressor are the same as those of the compressor according to Embodiment 1.
Although present invention has been described above by referring to Embodiments 1 and 2, needless to say, the present invention is not limited to Embodiments 1 and 2 described above and may be modified and applied as appropriate without departing from the gist of the present invention.
For example, a protrusion may be provided on the rear wall 130 of the movable body 13a exclusively for the purpose of abutting the flange 431 or the circlip 51. Also, the protrusion may be configured to be able to abut the second thrust bearing 35b. In this case, the second thrust bearing 35b corresponds to the maximum inclination restriction member according to the present invention.
Furthermore, the compressor may be configured as a variable displacement single head swash plate type compressor by forming cylinder bores only in either of the first cylinder block 21 and second the cylinder block 23.
Also, the control mechanism 15 may be configured such that the control valve 15c is provided in the high-pressure passage 15b while the orifice 15d is provided in the low-pressure passage 15a. In this case, it is possible to adjust the opening degree of the high-pressure passage 15b using the control valve 15c. Thereby, the pressure in the control pressure chamber 13c can be increased quickly due to the pressure of refrigerant gas in the second discharge chamber 29b, and the discharge capacity can be increased quickly.
The present invention is applicable to air-conditioning apparatus and the like.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013-070750 | Mar 2013 | JP | national |
| 2013-129901 | Jun 2013 | JP | national |
| 2014-033591 | Feb 2014 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2014/058297 | 3/25/2014 | WO | 00 |
