KR20190014421A - Scorll compressor - Google Patents

Abstract

A scroll compressor according to the present invention includes: a first scroll; a second scroll which has a boss part; a rotary shaft which has a boss coupling groove such that the boss part of the second scroll is inserted into and coupled to the rotary shaft; and a bush bearing which is press-fitted with and coupled to an outer peripheral surface of the boss part and has an external lubrication layer to form a bearing surface with an inner peripheral surface of the boss coupling groove. The bush bearing includes: a base member which has a cylindrical shape and is press-fitted with an outer peripheral surface of the boss part; and a lubrication member which is integrally provided with an outer peripheral surface of the base member and forms a lubrication layer. With reference to an initial state in which the bush bearing is press-fitted with the boss part, the cylindricity of the outer surface of the bush bearing satisfies a range which is within 0.4% of an average thickness of the bush bearing. Accordingly, an interval between an outer peripheral surface of the bush bearing and an inner peripheral surface of the boss coupling groove may be uniformly maintained.

Description

[0001] SCROLL COMPRESSOR [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a scroll compressor, and more particularly to a scroll compressor in which a boss portion of an orbiting scroll is inserted into a rotary shaft to receive a rotational force.

The scroll compressor includes a non-orbiting scroll or a fixed scroll (hereinafter, referred to as a first scroll) coupled to an inner space of a casing, and an orbiting scroll (hereinafter referred to as a second scroll) An intermediate pressure chamber, and a discharge chamber between the first scroll and the first scroll while performing a motion.

Such a scroll compressor is widely used for compressing refrigerant in an air conditioner or the like because it can obtain a relatively high compression ratio as compared with other types of compressors, and smooth suction, compression and discharge strokes of the refrigerant can be obtained and stable torque can be obtained.

In a conventional scroll compressor, the eccentric portion of the rotating shaft is inserted into the boss portion provided in the second scroll, and the rotating force of the driving motor is transmitted to the second scroll. In this case, the rotating shaft is inserted in the shaft hole of the main frame for supporting the second scroll and is supported in the radial direction, while the first wrap provided on the first scroll and the second wrap provided on the second scroll are engaged with each other, Thereby forming a pair of compression chambers.

In the scroll compressor, when the power is applied to the drive motor to generate a rotational force, the second scroll is pivotally moved with respect to the first scroll by the rotation axis to form a pair of compression chambers, thereby sucking, compressing, .

At this time, the second scroll may be subjected to centrifugal force generated while swirling, gas generated by compressing the refrigerant, and gas repulsive force in a direction opposite to the centrifugal force, so that the behavior may become unstable. However, And the turning movement is continued as appropriate.

In the scroll compressor of the related art, the middle portion of the rotary shaft is supported by the main frame, while the eccentric portion provided at the upper end of the rotary shaft is coupled to the orbiting scroll, A large difference in height is generated between the points of action of applying the rotational force to the contact points. As a result, the rotary shaft is subjected to a large eccentric load, and the bearing efficiency due to the gas force is increased, so that the compression efficiency due to friction loss may be reduced. In addition, there is a problem that compressor noise is increased, reliability is lowered, and the length of the main frame is increased to increase the size of the compressor.

Conventionally, a boss coupling groove is formed at the upper end of the rotary shaft so as to be eccentric with respect to the axial center, and a boss portion of the second scroll is inserted and coupled to the boss coupling groove.

In this case, since the supporting point for supporting the rotating shaft and the operating point for transmitting the rotating force to the second scroll are located at the same height, the eccentric load received by the rotating shaft is reduced, thereby reducing the frictional loss and the compressor noise in the bearing supporting the rotating shaft, And the compressor can be miniaturized.

In the conventional scroll compressor as described above, a bush bearing must be provided between the outer circumferential surface of the boss portion and the inner circumferential surface of the boss engagement groove. The bush bearing is normally press-fitted into the inner circumferential surface of the boss engagement groove. This is because the bush bearing must be press-fitted into the inner circumferential surface of the boss coupling groove to effectively prevent the bush bearing from being disengaged or idle even when the bush bearing is thermally expanded by the operation heat of the compressor. If the bush bearing is press-fitted into the outer circumferential surface of the boss portion, the bush bearing may be detached from the boss portion due to thermal expansion due to the operation heat, or may be loose due to plastic deformation during press-

However, in the conventional scroll compressor as described above, when the bush bearing is press-fitted into the boss coupling groove, the inner peripheral surface of the bush bearing forms a bearing surface, but the bearing surface is intensively rubbed at one point, There is a problem that the life is shortened.

Accordingly, a prior art patent registered in Korea on Aug. 28, 2015 (Korean Patent No. 101549868 (2015.08.28), "Bushing for Compressor and Scroll Compressor Comprising the Same") is characterized in that a bush bearing is inserted into the outer peripheral surface of the boss portion An example is given.

In the prior patent, a double bush bearing in which the bush bearing is formed only of a lubricating material or a double bush bearing in which a lubrication member made of a lubricating material is provided on the outer circumferential surface of a base material made of a methyl material has been introduced. In the prior art, the physical property or structure of the lubricating member is limited so that the single bush bearing or the double bush bearing is stably inserted or inserted into the boss portion of the orbiting scroll and fixed. Therefore, the prior art does not mention a manufacturing method for the dimension management of the bush bearing, particularly the lubrication member.

However, the bush bearing of the conventional scroll compressor limits the physical properties of the lubrication member as described above. In the manufacturing process, the lubricating member is out of the original design value and the outer diameter of the bush bearing increases, Friction loss occurs on the surface of the bush bearing, and a part of the lubrication member wears down, shortening the service life of the bush bearing.

Further, in the conventional scroll compressor, the thickness of the lubrication member is not constant in the bush bearing. As a result, the degree of thermal expansion of the lubrication member differs depending on the position due to the operation heat generated during operation of the compressor, There is a problem that abrasion occurs.

Prior patent: [Korean Patent No. 101549868 (2015.08.28), "Bushing Bearing for Compressor and Scroll Compressor Having Same")

SUMMARY OF THE INVENTION It is an object of the present invention to provide a bearing structure in which when a bush bearing is inserted into a boss portion of an orbiting scroll which is inserted into and engaged with a boss coupling groove of a rotary shaft and the outer peripheral surface of the bush bearing forms a bearing surface, So that the gap between the inner circumferential surfaces can be uniformly maintained.

Another object of the present invention is to maintain the outer diameter of the bushing bearing uniformly so as to prevent the outer diameter of the bushing bearing from becoming more uneven even when a high operating temperature is generated during operation of the compressor, And to provide a scroll compressor capable of minimizing the friction loss between the boss engagement groove and the boss portion of the orbiting scroll and the wear of the bush bearing.

In order to achieve the object of the present invention, there is provided a bush bearing having an outer lubricating layer, characterized in that a lubricating member made of a lubricating material is injection-molded on the outer peripheral surface of a cylindrical base member and a cut surface is formed at both ends of the lubricating member. Can be provided.

Further, in order to achieve the object of the present invention, there is provided a method of manufacturing a metal mold, comprising the steps of: forming a base member in a cylindrical shape; inserting the base member into a metal mold; injecting an injection material to form an injection product; A bush bearing having an outer lubrication layer formed by secondary processing of the outer diameter of the heat-treated bamboo article, Can be provided.

Here, when the injection mold is injected into the mold, the injection mold is injected in the longitudinal direction and overmolded so that the injection mold is further outward than the end of the base member on the opposite side of the mold inlet for injecting the injection mold, Can be cut and removed at the time of the primary machining.

Then, the working thickness of the primary working can be made larger than the working thickness in the secondary working.

Further, in order to achieve the object of the present invention, there is provided a scroll fluid machine including: a first scroll having a first wrap formed on one side of a first hard plate; A second scroll formed on one side surface of the second hard plate portion, the second scroll forming a compression chamber by engaging with the first lip, and a boss portion formed on the other side surface of the second hard plate portion; A rotating shaft having a boss coupling groove for receiving and coupling the boss portion of the second scroll; And a bush bearing having an outer lubricant layer so that the outer peripheral surface thereof forms an inner circumferential surface and a bearing surface of the boss engagement groove, wherein the bush bearing is formed in a cylindrical shape, A base member press-fitted into the outer circumferential surface; And a lubrication member integrally formed on an outer circumferential surface of the base member to form a lubricant layer, wherein an outer circumferential cylindrical surface of the bush bearing has a cylindrical shape with respect to an initial state in which the bush bearing is press- And the inner diameter of the bush bearing is less than 0.4% of the average thickness of the bush bearing.

Further, in order to achieve the object of the present invention, there is provided a scroll fluid machine including: a first scroll having a first wrap formed on one side of a first hard plate; A second scroll formed on one side surface of the second hard plate portion, the second scroll forming a compression chamber by engaging with the first lip, and a boss portion formed on the other side surface of the second hard plate portion; A rotating shaft having a boss coupling groove for receiving and coupling the boss portion of the second scroll; And a bush bearing having an outer lubricant layer so that the outer peripheral surface thereof forms an inner circumferential surface and a bearing surface of the boss engagement groove, wherein the bush bearing is formed in a cylindrical shape, A base member press-fitted into the outer circumferential surface; And a lubricating member integrally formed on an outer circumferential surface of the base member to form a lubricating layer, wherein the bush bearing is press-fitted into the boss portion, and after the bush bearing is operated for two hours at 210 DEG C, Is formed such that an outer circumferential cylindrical surface of the bush bearing is less than 0.5% of an average thickness of the bush bearing.

Here, the rate of change in distance between the outer circumferential surface of the bush bearing and the inner circumferential surface of the boss engagement groove may be less than 0.4% of the average thickness of the bush bearing.

The base member may be formed of a material having a heat transfer coefficient smaller than or equal to that of the boss portion of the second scroll.

The base member may be formed of a material having the same material properties as the boss portion of the second scroll.

The lubrication member may contain carbon fibers in a resin system.

The carbon fibers may be exposed at both ends of the lubricating member.

The lubrication member may have a cut surface formed at both ends thereof.

The resin series may be formed of a PEEK material.

The carbon fibers may be arranged in the longitudinal direction of the base member.

The carbon fibers may be exposed at both ends of the lubricating member.

The base member and the lubrication member may be formed in a shape having no cut surface along the circumferential direction.

A knurling portion may be formed on an outer circumferential surface of the base member so as to enlarge an area of contact with the inner circumferential surface of the lubricant member.

When the thickness of the base member is a, the thickness of the lubricating member is b, and the depth of the knurling portion is c, the following range can be satisfied. b / a = 1.09 to 1.15, c / a = 0.3 to 0.5

Further, in order to achieve the object of the present invention, there is provided a scroll fluid machine including: a first scroll having a first wrap formed on one side of a first hard plate; A second scroll formed on one side surface of the second hard plate portion, the second scroll forming a compression chamber by engaging with the first lip, and a boss portion formed on the other side surface of the second hard plate portion; A rotating shaft having a boss coupling groove for receiving and coupling the boss portion of the second scroll; And a bush bearing having an outer lubricant layer so that the outer peripheral surface thereof forms an inner circumferential surface and a bearing surface of the boss engagement groove, wherein the bush bearing is formed in a cylindrical shape, A base member press-fitted into the outer circumferential surface; And a lubricating member integrally formed on an outer circumferential surface of the base member to form a lubricating layer, wherein the lubricating member contains carbon fibers in a resin-based manner, and the carbon fibers are exposed at both ends of the lubricating member The scroll compressor can be provided.

The scroll compressor according to the present invention can suppress friction loss or wear between the boss portion of the orbiting scroll and the boss engagement groove of the rotary shaft as the outer diameter of the bush bearing is held substantially constant along the longitudinal direction, Compressor performance can be increased and lifetime can be extended.

In the scroll compressor according to the present invention, since the thickness of the lubricating member constituting the outer circumferential surface of the bush bearing is kept substantially constant along the longitudinal direction, even if a high operating temperature is generated during operation of the compressor, This makes it possible to more effectively suppress friction loss or wear between the boss portion of the orbiting scroll and the boss engagement groove of the rotary shaft, thereby enhancing the compressor performance and extending the service life.

1 is a longitudinal sectional view showing a scroll compressor according to the present invention,
Fig. 2 is a perspective view showing the orbiting scroll separated from the rotating shaft in the scroll compressor according to Fig. 1,
FIG. 3 is a perspective view showing a part of the bush bearing according to FIG. 1,
FIG. 4 is a cross-sectional half view of the bush bearing according to FIG. 3,
FIG. 5 is a block diagram for explaining a method (1) for manufacturing the bush bearing according to FIG. 3,
6 is a vertical sectional view showing a bush bearing manufactured according to the method (1)
Fig. 7 is a perspective view for explaining a secondary machining performed in a state in which the bush bearing manufactured according to the method (1) is press-fitted into the boss portion of the orbiting scroll,
8 is a block diagram for explaining a method (2) for manufacturing the bush bearing according to Fig. 3,
FIGS. 9A and 9B are longitudinal sectional views showing a bush bearing manufactured according to the method (2)
10 is a sectional view taken along the line "VI-VI" in Fig. 9B,
Fig. 11 is a perspective view for explaining secondary processing performed in a state in which the bush bearing manufactured according to the method (2) is press-fitted into the boss portion of the orbiting scroll,
12 is a graph showing changes in outer diameter of the lubricating member according to the manufacturing method of the bush bearing,
FIG. 13 is a graph showing a comparison of a cylindrical view of a lubricating member according to a manufacturing method of a bush bearing,
FIG. 14 and FIG. 15 are graphs comparing the change in outer diameter and the difference in cylindrical degree of the bush bearing in the operating condition of the scroll compressor according to FIG.

Hereinafter, a bush bearing having an external lubricating layer according to the present invention and a method of manufacturing the same will be described in detail with reference to an embodiment shown in the accompanying drawings.

The bush bearing according to the present invention can be applied to a case where the lubrication member having lubricity is manufactured. However, the present invention can also be applied to a case where a lubrication member is applied or laminated on the outer circumferential surface of a base member made of a metal as in this embodiment. In the following, the latter case will be taken as a representative example.

FIG. 1 is a longitudinal sectional view showing a scroll compressor according to the present invention, and FIG. 2 is a perspective view showing the orbiting scroll separated from a rotating shaft in the scroll compressor according to FIG.

The scroll compressor according to the present embodiment is provided with a driving motor 120 for generating a rotating force in an internal space of the casing 110. A main frame 130 is provided on the upper side of the driving motor 120, Can be fixedly installed. A fixed scroll 140 is fixedly installed on an upper surface of the main frame 130. An orbiting scroll 150 is installed between the main frame 130 and the fixed scroll 140. The orbiting scroll 150 is disposed between the fixed scroll 140 And can be eccentrically coupled to the rotary shaft 123 of the driving motor 120 to form a pair of compression spaces P continuously moving together with the rotary shaft 123. [ The orbiting scroll (160) may be installed between the fixed scroll (140) and the orbiting scroll (150) to prevent the orbiting scroll (150) from rotating.

The main frame 130 may be welded to the inner circumferential surface of the casing 110, and a shaft hole 131 may be formed at the center thereof. The feed water holes 131 may be formed to have the same diameter from the upper end to the lower end.

The fixed scroll 140 is formed with a fixed lap 142 protruding from the bottom surface of the rigid plate 141 to form a compression space P together with the orbiting wrap 152 of the orbiting scroll 150 to be described later, A suction port 143 may be formed in the hard plate 141 of the suction pipe 140 so that the suction pipe 111 and the compression space P communicate with each other.

A discharge port 144 is formed at the center of the hard plate 141 of the fixed scroll 140 so that the compression space P communicates with the inner space of the casing 110. At the end of the discharge port 144, A check valve (not shown) for opening the discharge port 144 for stopping the discharge of the refrigerant into the compression space P through the discharge port 144 when the compressor is stopped, Can be installed.

The orbiting scroll 150 protrudes from the upper surface of the longitudinal plate portion 151 and is engaged with the fixed lap 142 of the fixed scroll 140 to form the orbiting wrap 152 to form a pair of two compression spaces P The boss unit 153 may be formed on the bottom surface of the end plate 151 of the orbiting scroll 150 so as to be inserted into the boss coupling groove 123d of the rotation shaft 123 to be described later to receive the rotational force.

The boss 153 may be formed at the geometric center of the orbiting scroll 150. The boss 153 may be formed in a circular cylinder shape to reduce the weight of the orbiting scroll 150. [

The rotary shaft 123 is provided with a shaft portion 123a which is press-fitted into the rotor 122 of the drive motor 120 and a shaft portion 123b which is provided on both upper and lower sides of the shaft portion 123a, A bearing portion 123b and a sub bearing portion 123c and a boss coupling groove 123d which is eccentrically formed at the upper end of the main bearing portion 123b and into which the boss portion 153 of the orbiting scroll 150 is inserted . The eccentric mass 180 for canceling the eccentric load generated when the orbiting scroll 150 is rotated may be engaged with the main bearing portion 123b or the shaft portion 123a.

In the drawing, reference numeral 112 denotes a discharge tube, and reference numeral 121 denotes a stator.

The scroll compressor according to this embodiment has the following operational effects.

That is, when power is applied to the driving motor 120 to generate a rotational force, the orbiting scroll 150 eccentrically coupled to the rotating shaft 123 rotates in parallel with the fixed scroll 140, So that a pair of compression spaces P are formed.

The compression space P is continuously formed in several stages in the compression space P where the volume gradually becomes narrower in the direction of the discharge port (or the discharge chamber) 144 from the suction port (or the suction chamber)

The refrigerant supplied from the outside of the casing 110 flows through the suction port 143 of the fixed scroll 140 through the suction pipe 111. The refrigerant is moved in the direction of the final compression space by the orbiting scroll 150 . And then discharged into the internal space of the casing 110 through the discharge port 144 of the fixed scroll 140 in the final compression space.

1, the boss portion 153 of the orbiting scroll 150 is inserted into the boss engagement groove 123d of the rotation shaft 123 and is coupled to the main frame 130, It is possible to eliminate the difference in height (DELTA h = 0) between the supporting point A and the point of action B of the rotary shaft 123 acting on the orbiting scroll 150. [ Accordingly, the eccentric load received by the rotating shaft 123 can be reduced, thereby reducing the frictional loss in the main bearing portion 123b and improving the compression efficiency. In addition, the force acting on the welding points (C, D) between the casing 110 and the main frame 130 can be lowered to reduce compressor noise and improve reliability.

In addition, the eccentric load received by the rotary shaft 123 can be reduced to reduce the weight of the eccentric mass 180 installed on the rotary shaft 123, the material cost, and the deformation amount of the rotary shaft 123, thereby improving the compression efficiency. In addition, the force acting on the welding point C (D) between the casing 110 and the main frame 130 due to the centrifugal force of the eccentric mass 180 also lowers the compressor noise and improves the reliability.

In addition, since a separate pocket groove is not required in the main frame 130, the length and diameter of the main frame 130 in the axial direction can be reduced to reduce the material cost, and the axial length of the compressor can be reduced, . In addition, it is possible to increase the lamination height of the motor within the axial length of the limited compressor, thereby improving the performance of the compressor.

A bush bearing 200 for lubrication between the boss 153 and the boss coupling groove 123d is formed between the boss 153 of the orbiting scroll 150 and the boss coupling groove 123d of the rotary shaft 123 Can be installed.

In addition to the bush bearing 200, needle bearings, roller bearings, ball bearings, and the like can be applied. However, since these bearings are large in size, the bearing hole 131 of the main bearing is enlarged and friction loss may be increased. Therefore, it is preferable that the bush bearing is applied as in the present embodiment.

The bush bearing 200 according to the present embodiment may be preferable to be coupled to the boss portion 153 of the orbiting scroll 150 to be coupled to the inner peripheral surface of the boss coupling groove 123d. That is, when the bush bearing 200 is coupled to the boss 153, the outer circumferential surface of the bush bearing 200 is brought into contact with the inner circumferential surface of the boss coupling groove 123d in all the states, It is possible to suppress the wear of the bush bearing which may be generated when any one point of the bush bearing 200 is concentratedly contacted, thereby remarkably reducing the damage of the bush bearing 200 due to wear.

For example, when the boss portion 153 of the orbiting scroll 150 is inserted into the boss engagement groove 123d of the rotation shaft 123, the center of the rotation shaft 123 of the orbiting scroll 150 rotates when the rotation shaft 123 rotates, The inner peripheral surface of the boss coupling groove 123d comes into contact with the entire outer peripheral surface of the boss portion 153 at one point. That is, the entire outer peripheral surface of the boss portion 153 comes into contact with one point of the inner peripheral surface of the boss engaging recess 123d.

Accordingly, the outer circumferential surface of the boss portion 153 is not in a concentrated contact with the inner circumferential surface of the boss coupling groove 123d, and the entire outer circumferential surface thereof is evenly contacted. Therefore, when the bush bearing is coupled to the outer circumferential surface of the boss portion, It is possible to prevent a certain point from being brought into intensive contact with the boss coupling groove.

The bush bearing may be a single bush bearing entirely made of a lubricating material, or a lubricating member made of a lubricating material may be applied to the outer circumferential surface of a base material made of a steel material through an insert injection or the like Stacked double bush bearings. In the following, double bush bearing is used as a reference. However, the present invention is intended to keep the outer diameter of the lubricating member substantially uniform and to suppress friction loss and abrasion between the boss portion and the boss coupling groove, more precisely between the outer peripheral surface of the bush bearing and the inner peripheral surface of the boss coupling groove, In addition to bushing bearings, the same applies to single bushings.

FIG. 3 is a perspective view showing a part of the bush bearing according to FIG. 1, and FIG. 4 is a half sectional view showing the bush bearing according to FIG.

As shown in the figure, the bush bearing 200 according to the present embodiment includes a base member 210 which is press-fitted into a boss portion of a scroll compressor or the like, a lubrication member 210 which is applied or laminated on the outer circumferential surface of the base member 210, (220).

The base member 210 may be formed of the same metal material as the boss portion of the orbiting scroll to which the bush bearing of this embodiment is to be press-fitted, or a metal material having similar physical properties. Accordingly, the base member 210 may have the same heat transfer coefficient as the boss unit 153 or may be formed of a material having the same material properties. However, the base member 210 is not limited to a metal material, and may be a material having greater rigidity than at least the lubrication member 220. [ Accordingly, the bush bearing according to the present embodiment can be firmly press-fitted into the member to be press-fitted.

Since the base member 210 is to be press-fitted into a member such as a boss, it is formed in an annular cross-sectional shape. The inner circumferential surface is not limited to a true circle but may be variously formed depending on the shape of the member to be press- The outer circumferential surface of the base member 210 may have a non-circular cross-sectional shape such that the lubricating member 220 is inserted into the outer circumferential surface of the base member 210, Can also be formed.

For example, a knurling portion 211 may be formed on the outer circumferential surface of the base member 210 to enlarge a contact area with the inner circumferential surface of the lubrication member 220. The knurling portion 211 may be formed in a rhombus shape as shown in FIG. 3 to prevent the lubrication member 220 from being separated from the base member 210 in the longitudinal direction.

Here, the deeper the depth of the knurling portion 211, the wider the contact area with the lubrication member 220, and the higher the adhesive force. However, if the depth of the knurled portion is too deep, the rigidity of the base member 210 may be lowered and the coupling force with the member to be press-fitted into the bush bearing 200 may be lowered.

In view of this, the depth of the nulling portion can be defined as follows. That is, with reference to FIG. 2, when the thickness of the base member is a, the thickness of the lubricant member is b, and the depth of the knurling portion is c, the following range can be satisfied.

b / a = 1.09 to 1.15

c / a = 0.3-0.5

Thus, in the case of a bush bearing having an outer diameter of 29.9 mm, the thickness of the bearing member is 0.8 to 1.5 mm, and the thickness of the lubricating member is 0.45 to 1.15 mm, the depth of the knurled portion can be about 0.24 to 0.75 mm .

If the knurling portion 211 is formed in a rhombic shape, it is not only difficult to extrude and form the base member 210, but also to prevent the smooth flow of the injection material from occurring even when the lubrication member 220 is injection- have.

Therefore, the knurled portion 211 may be formed of at least one protrusion that is long along the longitudinal direction on the outer circumferential surface of the base member 210. In this case, not only injection molding of the base member 210 is facilitated, but also the loosening of the lubrication member 220 relative to the base member 210 can be suppressed, which can be more advantageous than the rhombus shape. In this case, a plurality of the knurling portions 211 may be formed along the circumferential direction as well as the longitudinal direction.

The lubrication member 220 is inserted between the knurring portions 211 and coupled to the base member 210 and the lubrication member 220. As described above, when the plurality of nulling portions 211 are formed on the outer circumferential surface of the base member 210, The lubrication member 220 can be firmly coupled to the base member 210. In addition, In addition, it is possible to restrain the lubrication member 220 from being deviated in the longitudinal direction with respect to the base member 210 by the nulling portion 211, and also to suppress loosening in the circumferential direction.

Meanwhile, as described above, the lubricant member 220 is insert-injected into the outer circumferential surface of the base member 210 to form a lubricant layer. Accordingly, it may be desirable that the lubrication member 220 is formed of a material of good lubrication-free property, that is, a polyether ether ketone (PEEK) material having an ether ketone bond. In this case, it is preferable to mix the carbon fibers 222 together with the peaks 221 as shown in FIG. 4 to enhance durability.

Of course, the lubrication member 220 may be press-fitted into the outer circumferential surface of the base member 210 without being injection-molded. However, in this case, since the lubrication member 220 is a resin series such as a peak, the coefficient of thermal expansion of the lubrication member 220, the maximum push-in band or the minimum press- It is possible to smoothly serve as a bearing without being detached from the base member 210. [

To this end, the lubrication member 220 may be attached to the outer circumferential surface of the base member 210 using an adhesive. However, the method using the adhesive is relatively complicated in the manufacturing process. Therefore, it is preferable from the viewpoint of reliability and mass production that the lubrication member 220 is insert-injected onto the outer circumferential surface of the base member 210 by using a metal mold.

In fact, when the bush bearing 200 is applied to a compressor, the bush bearing 200 must not only maintain a stable cohesive force against the high operating temperature of the compressor, but also maintain a minimum dimensional change of the bush bearing 200 The friction loss between members can be reduced. However, when the lubrication member 220 is press-fitted into the outer circumferential surface of the base member 210, it is necessary to accurately calculate the press-in bar or the like as described above, but it may be difficult to accurately calculate it. Then, the lubrication member 220 may be deformed in the press-fitting process, so that the pressure input may not be sufficient, so that the lubrication member 220 can be removed from the base member 210. This is the same with the method of using the bonding agent. Also, these methods are not as efficient as the injection method in mass productivity. Therefore, a method in which the lubrication member 220 is insert-injected may be preferable.

However, in the method of applying or laminating the lubrication member 220 to the outer circumferential surface of the base member 210 by the insert injection method as described above, the lubrication member 220 may be deformed during the manufacturing process, Can be formed larger than the designed value.

For example, a process of insert-injecting a lubrication member into a base member is as follows. This will be described with reference to FIG. 5 to FIG.

5, the base member 210 is first inserted into the injection space of the mold, the injection material such as a peak is injected, and the injection molded product is drawn out from the mold through a general curing process (S11)

Next, the article to be heated is annealed by annealing. It is kept at about 270 ° C. for about 4 hours and then cooled at room temperature for about 2 hours. As a result, the stress of the peak due to heat shrinkage after injection is relaxed (S12)

Next, the length, inner diameter, and outer diameter of the heat-treated article are first cut to complete the production of the bush bearing (S13).

A bush bearing manufactured through the above process is shown in Fig. However, as described above, the final outer diameter of the bush bearing manufactured in the order of " injection, heat treatment ", " primary processing ", can be made larger than the designed outer diameter. In other words, it has been recognized that various dimensional control of the bush bearing can be precisely performed after the heat treatment step after the injection step and the first machining step.

However, researchers who propose this embodiment have found that it is difficult to manage the dimensions of the bush bearing due to the conventional manufacturing method, which is performed in the order of <injection → heat treatment → primary machining> through a lot of trial and error, I was able to find out. This will be described later in comparison with the circularity of the bush bearing according to the present embodiment.

That is, when the lubrication member 220 made of a lubricating material is injection-molded on the outer circumferential surface of the base member 210 made of a metal material, it is recognized that the lubrication member 220 having heat-sensitive characteristics is largely deformed during the injection process and the heat treatment process Has come. However, according to the research results of the researchers who proposed the present embodiment, it has been found that the lubrication member 220 is thermally deformed more largely in the cutting process than the degree of the lubrication member 220 being deformed in the heat treatment process.

For example, if the amount of deformation of the lubrication member 220 in the heat treatment process is about 1 mu m, the deformation amount in the cutting process is about 7 mu m. This can be seen from the experimental graph of FIG. 10 to be described later. Further, if the cutting process is performed after the heat treatment after the injection, the lubrication member 220 is more swollen in the heat treatment process, so that the thickness of the lubrication member 220 is increased, and the amount to be cut is further increased. As a result, the cutting heat is greatly increased due to the increase of the cutting resistance in the cutting process. Therefore, even though the lubrication member 220 is cut according to the design value, the thickness of the final lubrication member 220 is designed Lt; / RTI &gt; value.

Accordingly, when the circularity of the bushing bearing is measured after completion of the first cutting operation, although the cutting operation is finally performed to reach a desired design value with respect to the outer diameter of the lubrication member 220, And the outer diameter of the inner surface of the outer tube was deformed more than the desired design value.

In addition, as described above, in addition to the peaks 221, additions such as the carbon fibers 222 may be added to the molded product to improve the abrasion resistance and the mechanical properties of the lubrication member 220. However, in this case, the additive is injected together with the peaks, and the additive bundle 222a is formed as a kind of vortex at the opposite end (hereinafter referred to as the rear end) 202 of the side (hereinafter referred to as the front end) And the thickness of the rear end of the lubrication member 220 becomes thicker due to the addendum 222a, so that the cutting heat can be further increased during cutting. The difference between the outer diameter D1 of the front end of the bush bearing 200 and the outer diameter D2 of the rear end of the bush bearing 200 can be further increased.

Accordingly, in this embodiment, a method of manufacturing a bush bearing capable of efficiently managing the dimension of the bush bearing by minimizing thermal deformation of the lubrication member 220 has been proposed. This is referred to as a method according to the present embodiment. We will examine this later in more detail.

Meanwhile, as described above, the bush bearing manufactured as described above is inserted into the boss coupling groove by press-fitting into the boss portion of the orbiting scroll, thereby coupling the rotary shaft and the orbiting scroll. At this time, the bush bearing is machined again once the outer diameter is press-fitted into the boss portion.

This will be described with reference to FIGS. 5 and 7. FIG.

That is, the bush bearing 200 is press-fitted into the outer peripheral surface of the boss unit 153 to fix the bush bearing 200 (S14)

Next, the outer diameter of the bush bearing 200 is secondarily cut and machined so that the outer diameter of the bush bearing 200 is appropriately matched to the outer diameter of the orbiting scroll 150 while the bush 153 is press-fitted into the outer peripheral surface of the boss 153. [ Thus, the outer diameter of the bush bearing 200 is designed to obtain a desired design value (S15)

However, as described above, the final outer diameter of the bush bearing to be coupled to the boss portion proceeds in the order of < injection → heat treatment → primary processing, and then &lt; .

Thus, as described above, in this embodiment, the injection molded article is subjected to a first cutting process (hereinafter referred to as a primary process), followed by a heat treatment process, and the heat-treated bush bearing is pressed into the boss portion The secondary deformation (hereinafter referred to as secondary machining) is performed again to minimize the thermal deformation that may occur during the cutting process of the lubrication member 220. That is, the present embodiment proceeds in the order of < injection > primary processing &gt; heat treatment &gt;

For example, as shown in FIG. 8, an article to be coated with the lubricant member 220 is manufactured on the outer circumferential surface of the base member 210 through the insert injection process described in the method (1). (S21)

However, in this embodiment, as shown in FIG. 9A, the overmolding part 225 is further formed at one end of the lubrication member 220. To this end, an overmolding space extending from the molding space is formed on the rear end side of the molded article from both ends of the base member 210. This overmolding space is a space for overmolding so that the overmolding portion 225 is formed at the rear end of the article to be printed. Accordingly, the injection molded article is formed with an over-molding part 225 extending longer than the end of the base member 210 on the opposite side of the injection molded article.

The carbon fibers 22 are injected together with the peaks 221 in the injection material. The carbon fibers 222 are arranged long in the injection direction. However, since the opposite side of the molding inlet to which the injection material is injected, that is, the rear end 202, becomes clogged, the peak 221 as an injection product and the carbon fiber 222 as an additive ) Forms a vortex. As a result, the carbon fibers 222 having the peaks 221 and the carbon fibers 222 are gathered together to form a fiber bundle 222a as a bundle of additives.

However, in this embodiment, since the over molding space extending from the molding space is formed outside the rear end of the base member 210, the fiber bundles 222a are formed in the over molding space without being formed in the molding space. This forms an overmolded portion 225 in the article of manufacture. The overmolding part 225 does not exist in the range of the base member 210 but is formed of a material that forms the lubrication member 220 only outside the range of the base member 210.

Next, the drawn article is taken out of the mold and subjected to primary machining of the outer diameter (S22)

For example, if the desired outer diameter of the desired bushing bearing is 29.9 mm, if the outer diameter of the article withdrawn from the mold is about 30.6 mm, then cut about 0.5-0.6 mm through primary processing.

In addition, in the first machining step, the length of the lubrication member 220, which forms the cutting surface and the outer peripheral surface, is also cut with respect to the inner diameter of the base member 210, which forms the inner peripheral surface of the bush bearing 200. At this time, as shown in FIG. 9B, not only the front end 201 constituting the molding inlet is cut, but also the over molding part 225 of the opposite end 202 is also cut and removed. Then, the injection product is formed into a cylindrical shape having the final length of the bush bearing 200. 10, the cut surfaces of the carbon fibers 225 may be exposed to the outside on the front surface 220a and the rear surface 220b of the lubrication member 220, respectively.

Next, the primary processed article is subjected to annealing treatment under the conditions described in the method (1) to form a bush bearing (S23)

As a result, the internal stress of the peak material constituting the lubricant member 220 is relaxed. In this process, the lubrication member 220 may be slightly swollen, but this is only negligible compared to the deformation caused by the cutting heat in the primary machining.

11, the heat-treated bush bearing 200 is press-fitted into the outer circumferential surface of the boss portion 153 to be engaged. (S24) Then, the bush bearing 200 is pressed into the boss portion 153, (S25). &Lt; RTI ID = 0.0 &gt;

For example, if roughly 0.5 to 0.6 mm is machined in the first machining step, the outer diameter of the bushing bearing can be made to reach the initial design value of 29.9 mm by machining about 0.1 to 0.2 mm in the second machining step .

As a result, relatively high cutting heat is generated while cutting relatively more in the first machining process, which can further deform the lubrication member 220, which is relatively small in the secondary machining, Whereby further deformation of the lubrication member 220 can be minimized. Accordingly, the original design value for the outer diameter of the bush bearing can be satisfied as the remaining portion is cut and removed through the secondary machining.

FIG. 12 is a graph showing changes in outer diameter of a lubricating member according to a manufacturing method of a bush bearing. This comparison compares the outer diameter of the bearing by proceeding the machining process by using the two methods described above, after manufacturing an article with a peak and carbon fiber lubrication member on the outer peripheral surface of the base member by the insert injection method.

As shown in the figure, when the bush bearing is manufactured by the method (1) in which the heat treatment is performed after the injection and the outer diameter of the product is cut, the outer diameter of the bush bearing is kept almost the same from the front end of the molding inlet to the rear end of the opposite end. However, it can be seen that the outer diameter increases sharply toward the rear end. It can be seen that the outer diameter of the lubrication member 220, which is a peak material, is significantly deformed while the cutting resistance generated during cutting is significantly increased at the rear end of the bearing.

Particularly, in the case of the method (1), since the overmolding space is not formed in the mold, an overmolding portion can not be formed on the article to be formed so that a bundle of appendages (fiber bundle) is formed near the rear end of the bearing, The amount of cutting to be performed by the bundle of additives is increased and the cutting resistance is increased to increase the cutting heat. As a result, even though the cutting process is finally performed so as to reach the initial design value, Is significantly increased at the rear end than at the front end.

On the other hand, in the case of manufacturing the bush bearing by the method according to the present embodiment (hereinafter referred to as the method (2)) in which the first machining is performed after the injection, and the second machining is performed after the heat treatment is performed, It can be seen that the outer diameter of the bearing is maintained almost constant up to the rear end. Of course, the outer diameter of the bearing at the rear end slightly increases, but this is negligible compared to the method (1). In the case of forming the lubrication member 220 of the bush bearing according to the method (2), the outer diameter is divided into the primary processing and the secondary processing with respect to the article to be processed, so that the occurrence of the cutting heat is reduced And it is possible to minimize the deformation of the lubrication member 220 made of the peak material by the cutting heat. Furthermore, in the method (2), an over molding space is formed in the mold to form an over molding part 225 in the product, and a fiber bundle 222a is formed in the over molding part 225, It is possible to prevent the bundle 222a from reaching the rear end and weighting the cutting heat in advance. As a result, the outer diameter of the bearing can be prevented from increasing sharply at the rear end side as in the method (1).

On the other hand, this can be seen from a comparison of the cylindrical view shown in Fig. That is, the results shown in FIG. 13 are obtained by comparing the cylinder diameters of the outer circumferential surfaces of the respective bush bearings manufactured according to the methods (1) and (2), and the average value of the outer circumferential cylindrical surfaces of the plurality of bush bearings I think. Here, the outer circumference cylindrical value is a value obtained by measuring an outer diameter of a plurality of positions in a range from a front end to a rear end with respect to each of the bush bearings, and obtaining an average of the outer diameter change values with respect to the plurality of positions.

As shown in the figure, in the method (1), the average degree of cylinder (hereinafter, the degree of the cylinder) is about 12 占 퐉 while the degree of the degree of cylinder is about 4 占 퐉 in the method?. That is, when the average thickness of the bush bearing used in the present embodiment is approximately 1.95 mm, the cylinder degree in the method (1) is approximately 0.62%, while the cylinder degree in the method (2) is approximately 0.2% . Therefore, considering the measurement error, etc., the cylinder degree can be within 0.3 to 0.4%. However, as described above, in the method (1), the degree of the cylinder can be at least 0.62%, and it can be seen that the degree of the cylinder is improved by about 1/2 compared with the method (1).

As a result, the cylinder diameter is improved while suppressing the outer diameter from being deformed at one end (rear end) of the bushing bearing as compared with the case of the method (2). Can be reduced. This can be seen by referring again to FIG. That is, in the case of the method (2), the difference in outer diameter at both ends of the lubricating member is about 1 to 2 탆, which can be within about 3% of the average thickness of the lubricating member, On the other hand, in the method (1), the difference in outer diameter at both ends of the lubricating member is about 7 to 8 탆.

Since the cylinder diameter is small as described above, it means that the outer diameter of the bush bearing is not greatly changed. Therefore, when the outer diameter of the bush bearing is machined, it can be processed into a uniform depth, The reliability of the bearing can be increased.

Meanwhile, when the bush bearing 200 is applied to the scroll compressor as described above, the change in the outer diameter of the bush bearing 200 greatly affects the performance and reliability of the product.

The bush bearing 200 may be pressed into the boss 153 of the orbiting scroll 150 and serve as a bearing with the boss coupling groove 123d of the rotation shaft 123. [ have.

In this case, since the outer diameter of the bush bearing according to the method (1) is not uniform and the outer diameter of the lubrication member 220 increases to the rear end (lower end) 202, the outer diameter of the bush bearing 200 is uniformly managed Becomes very difficult. That is, if the outer diameter of the bush bearing 200 is uniformly changed, the entire outer diameter of the bush bearing 200 can be deepened to match the original design value. However, if only a part of the outer diameter of the bush bearing 200 is abnormally deformed, it becomes difficult to uniformly manage the whole body.

The outer circumferential surface of the bush bearing 200 may be excessively brought into close contact with the inner circumferential surface of the boss engagement groove 123d to generate a friction loss and to cause uneven wear of the bush bearing 200. [ As a result, the inclination of the orbiting scroll 150 is increased, so that the refrigerant leaks in the compression chamber and the compression efficiency may be lowered.

The bush bearing 200 according to the method 2 can maintain the outer diameter of the lubricant member 220 uniform even when the bush bearing 200 is press-fitted into the boss 153, Friction loss with the inner peripheral surface of the coupling groove 123d and uneven wear of the bush bearing can be suppressed. In addition, tilting of the orbiting scroll (150) can be suppressed and leakage of the compression chamber can be suppressed.

In particular, when the bush bearing 200 is applied to a scroll compressor, the problems described above can be further exacerbated as the lubrication member 220 thermally expands due to heat generated during operation of the compressor. The greater the thickness of the lubrication member 220, the greater the degree of thermal expansion.

However, since the thickness of the lubricating member 220 is kept substantially constant from the front end (upper end) 201 to the rear end (lower end) 202, the bush bearing 200 according to the method (2) The outer diameter D2 of the rear end (lower end) of the front end (upper end) 200 can be prevented from increasing substantially compared with the front end (upper end) outer diameter D1. Accordingly, the degree of thermal expansion of the lubrication member 220 can be kept relatively small even by heat generated during operation of the compressor.

Figs. 14 and 15 are diagrams showing changes in the outer diameter of the bushing bearing and a change in the diameter of the cylinder after the bush bearing according to the method (1) is applied to the scroll compressor and the bush bearing according to the method This is a graph showing the difference in degrees.

As shown in FIG. 14, when the outer diameter of the bushing bearing is exposed to the same operating conditions as described above, it can be seen that the method 1 is about 22 μm and the method 2 is about 6 μm. This is because the thickness of the lubricating member 220 in the method (2) is kept thin compared to the method (1).

This can be seen from a comparison of the cylindrical view shown in Fig. In other words, if the average value of the design value of the bush bearing applied to the present embodiment is about 1.95 mm, the change in the cylindrical surface of the bush bearing relative to the bush bearing after the compressor is operated under the above- The average outer diameter of the outer circumferential surface in method (1) is about 1.13%, but in the case of method (2), the degree of cylindrical is about 0.31%. Therefore, considering the measurement error, the cylindrical surface of the outer periphery of the bush bearing 200 according to the present embodiment may be within 0.5%. As a result, it can be seen that the difference in the degree of cylinder between the method (2) and the method (1) is greatly improved to about 1/4 to 1/3.

In other words, it can be seen that there is less thermal deformation in the case of the method (2) than in the case of the method (1) in the cylinder diameter difference for each of the bush bearings manufactured according to the method (1) and the method (2) under the above operating condition. This can be expected to exert a considerable effect in consideration of the fact that the gap between the bush bearing and the boss coupling groove is controlled within 100 占 퐉.

As a result, in the case of the method (2), the increase in thickness of the actual lubrication member 220 is minimized by lowering the cutting heat generated in the cutting process, and when applied to a compressor or the like, the thermal expansion due to the operation heat of the compressor can be minimized . As a result, the overall outer diameter change of the bushing bearing is significantly lower than that of the method (1), thereby improving the performance and reliability of the compressor to which the bush bearing is applied.

123: rotation axis 123d: boss coupling groove
130: Main frame 131: Bearing hole
140: fixed scroll 142:
142: stationary lap 150: orbiting scroll
152: turning wrap 153: boss portion
200: Bush bearing 201: Front end of the article
202: rear end of the article of manufacture 210: base member
211: Knurled portion 220: Lubricating member
220a: front end of the lubrication member 220b: rear end of the lubrication member
221: Peak 222: Carbon fiber
222a: fiber bundle 225: overmolding part

Claims (15)

A first scroll having a first wrap formed on one side of the first hard plate;
A second scroll formed on one side surface of the second hard plate portion, the second scroll forming a compression chamber by engaging with the first lip, and a boss portion formed on the other side surface of the second hard plate portion;
A rotating shaft having a boss coupling groove for receiving and coupling the boss portion of the second scroll; And
And a bush bearing having an outer lubricant layer so that an outer circumferential surface thereof forms an inner circumferential surface and a bearing surface of the boss engagement groove,
Wherein the bush bearing comprises:
A base member formed in a cylindrical shape and press-fitted into an outer peripheral surface of the boss portion; And
And a lubricating member integrally formed on an outer circumferential surface of the base member to form a lubricating layer,
Wherein an outer circumferential cylindrical surface of the bush bearing is formed to be within 0.4% of an average thickness of the bush bearing on the basis of an initial state in which the bush bearing is press-fitted into the boss portion. A first scroll having a first wrap formed on one side of the first hard plate;
A second scroll formed on one side surface of the second hard plate portion, the second scroll forming a compression chamber by engaging with the first lip, and a boss portion formed on the other side surface of the second hard plate portion;
A rotating shaft having a boss coupling groove for receiving and coupling the boss portion of the second scroll; And
And a bush bearing having an outer lubricant layer so that an outer circumferential surface thereof forms an inner circumferential surface and a bearing surface of the boss engagement groove,
Wherein the bush bearing comprises:
A base member formed in a cylindrical shape and press-fitted into an outer peripheral surface of the boss portion; And
And a lubricating member integrally formed on an outer circumferential surface of the base member to form a lubricating layer,
The outer circumferential cylindrical surface of the bush bearing is formed to be within 0.5% of the average thickness of the bush bearing, based on the state after the bush bearing is press-fitted into the boss portion and operated for 2 hours at 210 ° C And the scroll compressor. 3. The method according to claim 1 or 2,
Wherein a rate of change in spacing between an outer circumferential surface of the bush bearing and an inner circumferential surface of the boss engagement groove is less than 0.4% of an average thickness of the bush bearing. 3. The method according to claim 1 or 2,
Wherein the base member is formed of a material having a heat transfer coefficient smaller than or equal to that of the boss portion of the second scroll. 5. The method of claim 4,
Wherein the base member is formed of a material having the same material properties as the boss portion of the second scroll. 3. The method according to claim 1 or 2,
Wherein the lubrication member contains carbon fibers in a resin-based manner. The method according to claim 6,
Wherein the carbon fibers are exposed at both ends of the lubricating member. The method according to claim 6,
Wherein the lubricating member is formed with a cut surface at both ends thereof. The method according to claim 6,
Wherein the resin system is a PEEK material. The method according to claim 6,
Wherein the carbon fibers are arranged in the longitudinal direction of the base member. 11. The method of claim 10,
Wherein the carbon fibers are exposed at both ends of the lubricating member. 3. The method according to claim 1 or 2,
Wherein the base member and the lubrication member are formed in a shape having no cut surface along the circumferential direction. 13. The method of claim 12,
Wherein a knurling portion is formed on an outer circumferential surface of the base member such that an area of contact with the inner circumferential surface of the lubricating member is enlarged. 14. The method of claim 13,
The thickness of the base member is a, the thickness of the lubricating member is b, and the depth of the knurling portion is c, the following range is satisfied.
b / a = 1.09 to 1.15,
c / a = 0.3 to 0.5 A first scroll having a first wrap formed on one side of the first hard plate;
A second scroll formed on one side surface of the second hard plate portion, the second scroll forming a compression chamber by engaging with the first lip, and a boss portion formed on the other side surface of the second hard plate portion;
A rotating shaft having a boss coupling groove for receiving and coupling the boss portion of the second scroll; And
And a bush bearing having an outer lubricant layer so that an outer circumferential surface thereof forms an inner circumferential surface and a bearing surface of the boss engagement groove,
Wherein the bush bearing comprises:
A base member formed in a cylindrical shape and press-fitted into an outer peripheral surface of the boss portion; And
And a lubricating member integrally formed on an outer circumferential surface of the base member to form a lubricating layer,
Wherein the lubricating member contains carbon fibers in a resin-based manner, and the carbon fibers are exposed at both ends of the lubricating member.

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