Description VARIABLE CAPACITY SWASH PLATE TYPE COMPRESSOR

Technical Field

[1] The present invention relates to a variable capacity swash plate type compressor, and more particularly, to a variable capacity swash plate type compressor, which has an elastic member mounted on a driving shaft located between a rotor and a swash plate for pushing a swash plate in a direction that an inclination angle is decreased to always contact and support a side of the swash plate to the rotor when the inclination angle of the swash plate is varied, thereby preventing a vibration of the swash plate and reducing noise during operation. Background Art

[2] In general, a compressor constituting an air conditioning device of an automobile is a device for selectively receiving driving power from a power source by a restricting action of an electromagnetic clutch, compressing refrigerant gas by a straight reciprocating motion of pistons after absorbing the refrigerant gas from an evaporator, and discharging it toward a condenser. Such a compressor is classified into various kinds according to compression methods and structures, and out of the compressors of the various kinds, a variable capacity compressor, which can vary a compression volume, has been widely used.

[3] Hereinafter, referring to FIGS. 1 and 2, a prior art variable capacity swash plate type compressor will be described as an example.

[4] The variable capacity swash plate type compressor 1 includes: a cylinder block 10 having a plurality of cylinder bores 11 formed inside the cylinder block 10 axially along a concentric circle; a front housing 20 mounted in front of the cylinder block 10 and having a crank chamber 21 formed therein; a rear housing 30 mounted at the back of the cylinder block 10 and having a suction chamber 31 and a discharge chamber 32 formed therein; a plurality of pistons 40 reciprocatingly inserted into each of the cylinder bores 11 of the cylinder block 10 and having a bridge 41 at the rear end portion thereof; a driving shaft 50 having an end portion rotatably passing through the front housing 20 and the other end portion rotatably inserted and mounted into the center of the cylinder block 10; a rotor 60 combined to the driving shaft 50 inside the crank chamber 21 and rotating with the driving shaft 50; a swash plate 70 mounted on the circumference of the driving shaft 50 by slidably combining a sleeve 65 thereto, having an edge rotatably mounted to an insertion space of the piston bridge 41 by interposing a shoe 45 between the insertion space and the edge of the swash plate 70, and connected with the rotor 60 via hinge means 75 so as to adjust its inclination angle

against the driving shaft 50 while rotating together with the rotor 60; and a valve unit 80 mounted between the cylinder block 10 and the rear housing 30 to inhale refrigerant from the suction chamber 31 into the cylinder bores 11 during a suction stroke and discharge compressed refrigerant from the cylinder bores 11 into the discharge chamber 32 during a compression stroke.

[5] In addition, the inclination angle of the swash plate 70 against the driving shaft 50 can be adjusted according to a pressure change inside the crank chamber 21 by a control valve 90 mounted in the rear housing 30.

[6] Furthermore, the compression coil spring 55 interposed on the driving shaft 50 between the rotor 60 and the swash plate 70 elastically supports the sleeve 65, to which the swash plate 70 is rotatably combined, against the rotor 60, so that the swash plate 70 can be returned to its original position.

[7] Meanwhile, the hinge means 75 for connecting the rotor 60 and the swash plate 70 with each other includes a first hinge arm 61 formed on a side of the rotor 60 and having a slot 62, and a second hinge arm 71 formed on a side of the swash plate 70 and having a hinge pin 72 movably combined to the slot 62 of the first hinge arm 61.

[8] As described above, in the variable capacity swash plate type compressor 1, a plu rality of the pistons 40 arranged along the concentric circle of the cylinder block 10 perform the and backward reciprocating motion in order by the rotation of the swash plate 70.

[9] Here, during the suction stroke of the pistons 40, a suction valve (not shown) of the valve unit 80 is opened by a drop of pressure inside the cylinder bores 11, whereby the cylinder bores 11 and the suction chamber 31 are fluidically communicated with each other and the refrigerant is induced from the suction chamber 31 into the cylinder bores 11.

[10] Additionally, during the compression stroke of the pistons 40, a discharge valve

(not shown) of the valve unit 80 is opened while the refrigerant is compressed by a rise of pressure inside the cylinder bores 11, whereby the cylinder bores 11 and the discharge chamber 32 are fluidically communicated with each other and the compressed refrigerant is discharged from the cylinder bores 11 into the discharge chamber 32.

[11] In addition, the swash plate 70 adjusts its inclination angle in correspondence to a difference between pressure inside the crank chamber 21 and suction pressure inside the cylinder bores 11, whereby a discharge volume of the compressor 1 is varied.

[12] Meanwhile, the slot 62 formed on the first hinge arm 61 of the rotor 60 guides the swash plate 70 when the inclination angle of the swash plate 70 is varied, and in this instance, keeps a fixed interval from the hinge pin 72 combined to the second hinge arm 71 of the swash plate 70 for a smooth operation.

[13] Therefore, when the compressor 1 is in a condition of the largest angle, the inclination angle of the swash plate 70 is varied to the largest angle, and in this instance, the compression coil spring 55 is compressed.

[14] During the process that the inclination angle the swash plate 70 is varied into the smallest angle or the largest angle, the hinge pin 72 guides an inclination motion of the swash plate 70 while moving along the slot 62.

[15] However, while the compressor 1 is operated, particularly, operated on the variable condition, the swash plate 70 is vibrated by the interval (S) formed between the hinge pin 72 and the slot 62, and so, noise is generated.

[16] The vibration of the swash plate 70 can reduce vibration and noise somewhat since the hinge pin 72 is at least in close contact with a side of the slot 62 in the condition of the smallest angle or the largest angle of the swash plate 70. However, since there is not structure for supporting the swash plate 70 in a section between the smallest angle and the largest angle, namely, since the hinge pin 72 is not in close contact with the inner circumference of the slot 62 but shakes, the swash plate 70 is vibrated and generates noise.

[17] Meanwhile, the compression coil spring 55 for restoring the swash plate 70 to its initial position applies elasticity only to the sleeve 65 rotatably mounted on the swash plate 70, and so, the swash plate 70 is freely moved in directions that the inclination angle is increased and decreased, whereby the hinge pin 72 also shakes inside the slot 62.

Disclosure of Invention

Technical Problem

[18] Accordingly, it is an object of the present invention to provide a variable capacity swash plate type compressor, which has an elastic member mounted on a driving shaft between a rotor and a swash plate for pushing a swash plate in a direction that an inclination angle is decreased to always contact and support a side of the swash plate to the rotor when the inclination angle of the swash plate is varied, thereby preventing vibration of the swash plate and reducing noise during operation. Technical Solution

[19] To achieve the above objects, the present invention provides a variable capacity swash plate type compressor including: a cylinder block having a plurality of cylinder bores formed therein; a front housing mounted in front of the cylinder block and having a crank chamber formed therein; a rear housing mounted at the back of the cylinder block and having a suction chamber and a discharge chamber formed therein; a driving shaft rotatably mounted between the cylinder block and the front housing; a rotor combined to the driving shaft inside the crank chamber and rotating together with

the driving shaft; a swash plate connected to the rotor via hinge means, and mounted on the driving shaft by slidably combining a sleeve on the driving shaft to vary an inclination angle corresponding to a pressure change of the crank chamber; and an elastic member mounted on the driving shaft located between the rotor and the swash plate, the elastic member having a spring portion for pushing the swash plate on a rotational central line of the swash plate and a reverse inclination portion for pushing the swash plate at a position spaced apart at a predetermined distance from a rotational center of the swash plate in a direction that the inclination angle is decreased, wherein a side of the swash plate is kept in close contact with the rotor during variation of the inclination angle of the swash plate, whereby the swash plate is prevented from a vibration. Brief Description of the Drawings

[20] FIG. 1 is a sectional view of a prior art variable capacity swash plate type compressor.

[21] FIG. 2 is a partially enlarged view showing a state that a hinge pin of FIG. 1 is combined to a slot.

[22] FIG. 3 is a sectional view of a variable capacity swash plate type compressor according to the present invention.

[23] FIG. 4 is a perspective view showing a state where a swash plate and a rotor are disassembled from the compressor of FIG. 3.

[24] FIG. 5 is a sectional view showing a state when an inclination angle of the swash plate is at the smallest angle in the variable capacity swash plate type compressor according to the present invention.

[25] FIG. 6 is a sectional view showing a state when an inclination angle of the swash plate is at the largest angle in the variable capacity swash plate type compressor according to the present invention.

[26] FIG. 7 is a view showing an operated state of a reverse inclination portion in the variable capacity swash plate type compressor according to the present invention.

[27] FIG. 8 is a perspective view of another example of the reverse inclination portion of

FIG. 4.

[28] FIG. 9 is a sectional view showing a state where a part of a slot is omitted from the variable capacity swash plate type compressor according to the present invention. Mode for the Invention

[29] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

[30] FIG. 3 is a sectional view of a variable capacity swash plate type compressor according to the present invention, FIG. 4 is a perspective view showing a state where a swash plate and a rotor are disassembled from the compressor of FIG. 3, FIG. 5 is a

sectional view showing a state when an inclination angle of the swash plate is at the smallest angle in the variable capacity swash plate type compressor according to the present invention, FIG. 6 is a sectional view showing a state when an inclination angle of the swash plate is at the largest angle in the variable capacity swash plate type compressor according to the present invention, FIG. 7 is a view showing an operated state of a reverse inclination portion in the variable capacity swash plate type compressor according to the present invention, FIG. 8 is a perspective view of another example of the reverse inclination portion of FIG. 4, and FIG. 9 is a sectional view showing a state where a part of a slot is omitted from the variable capacity swash plate type compressor according to the present invention.

[31] As shown in the drawings, the variable capacity swash plate type compressor 100 includes: a cylinder block 110 having a plurality of cylinder bores 11 axially formed on a concentric circle; a front housing 120 mounted in front of the cylinder block 110 and having a crank chamber 121 formed therein; and a rear housing 130 mounted at the back of the cylinder block 110 and having a suction chamber 131 and a discharge chamber 132 formed therein.

[32] A plurality of pistons 140 having a bridge 141 at the rear end thereof are recip- rocatingly inserted and mounted to each of the cylinder bores 111 of the cylinder block 110.

[33] In addition, a driving shaft 150 has an end portion rotatably passing through the front housing 120 and the other end portion inserted into the center of the cylinder block 110 in such a way as to be rotatably supported.

[34] Moreover, a rotor 160 is combined to the driving shaft 150 inside the crank chamber 121 to rotate together with the driving shaft 150.

[35] Furthermore, a swash plate 170 is rotatably mounted on a sleeve 165 which is slidably combined to the driving shaft 150 inside the crank chamber 121, has an edge rotatably mounted to an insertion space of the piston bridge 141 by interposing a shoe 145 between the insertion space and the swash plate, and connected with the rotor 160 via hinge means 175 to adjust its inclination angle against the driving shaft 150 while rotating together with the rotor 160.

[36] Here, the swash plate 170 includes a hub 171 rotatably combined to the sleeve 165, which is slidably combined to the driving shaft 150, via a hub pin 166, and a swash plate board 172 combined to the outer peripheral surface of the hub 171.

[37] Additionally, the hinge means 175 for connecting the rotor 160 and the swash plate

170 with each other includes a first hinge arm 161 formed on a side of the rotor 160 and having a slot 162, and a second hinge arm 171 formed on a side of the swash plate 170 and having a hinge pin 172 movably combined to the slot 162 of the first hinge arm 161.

[38] In addition, a valve unit 180 is mounted between the cylinder block 110 and the rear housing 130 to inhale refrigerant from the suction chamber 131 into the cylinder bores 111 during a suction stroke of the pistons 140 and to discharge compressed refrigerant from the cylinder bores 111 to the discharge chamber 132 during a compression stroke.

[39] Meanwhile, a control valve 190 is mounted in the rear housing 130 and operationally fluidically communicates the discharge chamber 132 and the crank chamber 121 with each other to vary a difference between refrigerant suction pressure inside the cylinder bores 111 and gas pressure inside the crank chamber 121, whereby the inclination angle of the swash plate 170 can be adjusted.

[40] Moreover, an elastic member 155 is mounted on the driving shaft 150 between the rotor 160 and the swash plate 170, and has a spring portion 156 for pushing the swash plate 170 on a rotational central line of the swash plate 170 and a reverse inclination portion 157 formed at a position spaced apart at a predetermined distance (d) from the rotational center of the swash plate 170 for pushing the swash plate 170 in a direction that the inclination angle is decreased, whereby a side of the elastic member 155 is always in close contact with the rotor 160 when the inclination angle of the swash plate 170 is varied to prevent a vibration of the swash plate 170.

[41] That is, as shown in FIGS. 5 and 6, force (Fl) for pushing the swash plate 170 in a direction which is in parallel with the driving shaft 150 is applied to the spring portion 156, and force (F2) for pushing the swash plate 170 in a perpendicular direction (downward direction) to the driving shaft 150 is applied to the reverse inclination portion 157 at the position spaced apart at a predetermined distance (d) from the rotational center of the swash plate 170. Therefore, the spring portion 156 returns the swash plate 170 to an initial position, and the reverse inclination portion 157 pushes the swash plate 170 in the direction that the inclination angle is decreased.

[42] Meanwhile, FIG. 7 shows an operated state of the reverse inclination portion 157.

In FIG. 7, the reverse inclination portion 157 is located at different positions when the swash plate 170 is at the largest angle and at the smallest angle. That is, when the swash plate 170 is at the largest angle, since the position if reverse inclination portion 157 rises and elastically restoring force is generated, the reverse inclination portion 157 always pushes the swash plate 170 in the direction that the inclination angle is decreased while changing its position according to the inclination angle of the swash plate 170.

[43] Moreover, the reverse inclination portion 157 can be constructed of the following two types.

[44] First, as shown in FIG. 4, the reverse inclination portion 157 includes a support portion 158 formed integrally on an end portion of the spring portion 156 for directly supporting a side of the swash plate 170.

[45] Here, it is preferable that the support portion 158 extends to a predetermined length in a radial direction of the swash plate 170.

[46] Second, as shown in FIG. 8, the reverse inclination portion 157 is slidably combined to the driving shaft 150 located between the spring portion and the swash plate 170 in such a manner as to be separated from the spring portion 156, and includes an elastic portion 159 and a support portion 158a for directly supporting a side of the swash plate 170.

[47] The elastic portion 159 is formed by winding a coil in a circular form, and the support portion 158a is formed by extending both end portions of the elastic portion 159 in the radial direction of the swash plate 170.

[48] As described above, the reverse inclination portion 157 integrally or separately formed on the spring portion 156 receives elasticity from the spring portion 156 and pushes the swash plate 170 in the direction that the inclination angle is decreased while not being in close contact with the sleeve 165 but being in directly close contact with the hub 171 of the swash plate 170.

[49] That is, since the swash plate 170 is rotatably combined to the sleeve 165, which is slidably combined to the driving shaft 150, via the hub pin 166, the swash plate 170 can be freely moved in all directions that the inclination angle is increased and decreased, and in this instance, the reverse inclination portion 157 is elastically supported to push the swash plate 170 in the direction that the inclination angle is decreased.

[50] Therefore, when the compressor 100 is in the condition of the largest angle, the inclination angle of the swash plate 170 is increased and the spring portion 156 is gradually compressed. In this instance, since the swash plate 170 continuously receives elasticity only in the direction that the inclination angle is decreased by the reverse inclination portion 157, the hinge pin 174 is continuously moved while being in close contact with a side of the swash plate 170, which is close to the rotor 160, inside the slot 162.

[51] On the contrary, when the compressor 100 is in the condition of the smallest angle, the inclination angle of the swash plate 170 is decreased by restoring force of the spring portion 156, and also in this instance, since the swash plate 170 continuously receives elasticity only in the direction that the inclination angle is decreased by the reverse inclination portion 157, the hinge pin 174 is continuously moved while being in close contact with a side of the swash plate 170, which is close to the rotor 160, inside the slot 162.

[52] Meanwhile, the swash plate 170 has a stopper 176 formed on a side of the hub 171 for supporting the reverse inclination portion 157. That is, since the support portion 158 or 158a of the reverse inclination portion 157 is seated on the stopper 176 and

supported in stable, it can be prevented that the reverse inclination portion 157 is rotated on the driving shaft 150.

[53] As described above, the reverse inclination portion 157 is integrally or separately mounted on the end portion of the spring portion 156 to resiliently support the hub 171 of the swash plate 170 in direct, so that the swash plate 170 is pushed in the direction that the inclination angle is decreased, whereby the present invention can prevent vibration of the swash plate 170 and noise generated during operation of the compr essor 100 since the hinge pin 174 is always rotated in a state where it is in close contact with the side of the slot 162 when the inclination angle of the swash plate 170 is varied.

[54] Meanwhile, the present invention can reduce vibration and noise due to reduction of the interval by the reverse inclination portion 157 receiving elasticity from the spring portion 156 even though there is the interval between the hinge pin 174 and the slot 162 when the swash plate 170 is assembled.

[55] In addition, as described above, since the hinge pin 174 is always rotated in the state it is in close contact only with the side of the slot 162, as shown in FIG. 9, a part where the hinge pin 172 is not in close contact can be removed from the slot 162 of the first hinge arm 161, and so, the present invention can guide the inclination angle of the swash plate 170 without forming the slot 162, thereby simplifying the structure and reducing manufacturing costs.

[56] Moreover, if the slot 162 is removed, the hinge pin 174 is also removed, and in this instance, the present invention may have a structure that the second hinge arm 173 formed on the hub 171 is directly guided to an inclined surface of the first hinge arm 161 formed on the rotor 160.

[57] As described above, the prior art has the problem in that the swash plate 70 (in the prior art) is vibrated while the inclination angle of the swash plate 70 is varied since the compression coil spring 55 (in the prior art) is resiliently supported only on the sleeve 65 (in the prior art). However, the present invention can prevent the vibration of the swash plate 170 when the swash plate 170 is not only at the smallest angle or the largest angle but also in the section between the smallest angle and the largest angle during variation of the inclination angle of the swash plate 170 since the elastic member 155 having the spring portion 156 and the reverse inclination portion 157 directly supports the swash plate 170 or simultaneously supports the swash plate 170 and the sleeve 165. Industrial Applicability

[58] As described above, the present invention can prevent the vibration of the swash plate and reduce noise generated during operation of the compressor, since the reverse

inclination portion is formed at the end portion of the spring portion for pushing the swash plate in the direction that the inclination angle is decreased so that the hinge pin is rotated in the state where it is always in close contact with the side of the slot during variation of the inclination angle of the swash plate.

[59] In addition, the present invention can simplify the structure and reduce manufacturing costs, since the hinge pin is always rotated in the state it is in close contact only with the side of the slot, and so, a part where the hinge pin is not in close contact can be removed.