CN102454578A - Hermetic compressor - Google Patents

Abstract

The invention provides a hermetic compressor, which includes a hermetic container, a motor element and a compression element. The shaft of the compression element has a main shaft portion, a flange portion protruding from the main shaft portion, and an eccentric shaft portion connected to the flange portion. The main bearing has a thrust surface on which the flange portion of the shaft abuts and slides. The thrust surface consists of a first portion that is farther from the compression chamber than the central axis, and a second portion that is closer to the compression chamber than the central axis. The area of the first portion of the thrust surface is larger than the area of the second portion. The hermetic compressor has high efficiency and high reliability.

Description

hermetic compressor

technical field

The present invention relates to a hermetic compressor used in refrigerating cycles such as refrigerating refrigerators.

Background technique

A hermetic compressor includes, in a hermetic container, a block as a support frame, a compression element provided at the top of the block, and an electric element provided at the bottom of the block.

The shaft of the rotor to which the electric element is fixed is rotatably supported by a bearing portion provided substantially at the center of the cylinder. The rotation of the shaft transmits the driving force of the electric element to the compression element.

FIG. 8 is a longitudinal sectional view of a conventional hermetic compressor 500 . FIG. 9 is a plan view of the cylinder 9 of the hermetic compressor 500 .

The hermetic compressor 500 includes a hermetic container 1 and a shaft 2 . The rotor 3 and the stator 4 constitute a motor as an electric element. The shaft 2 is pressed into the rotor 3 .

One end of the connecting rod 5 is attached to a crank pin 11 as an eccentric portion of the shaft 2 . Piston pin 8 is installed on the other end of connecting rod 5, and is fixed on the piston 7. Connecting rod 5, piston pin 8, piston 7 and cylinder 6 form a compression element. The refrigerating machine oil 10 stagnates in the lower part of the airtight container 1 .

A crank pin 11 and a balance plate 12 are provided on the upper portion of the shaft 2 . The crank pin 11 rotates eccentrically, driving the piston 7 of the compression element to reciprocate. A thrust surface 14 that receives a thrust load is provided on an upper end surface of a bearing portion 15 of the cylinder 9 . The thrust surface 14 and the lower surface of the balance plate 12 directly slide, thus forming a thrust sliding part in the hermetic compressor 500 .

However, the efficiency of the conventional hermetic compressor 500 may decrease.

A hermetic compressor similar to the hermetic compressor 500 is disclosed in Japanese Patent Laid-Open No. 2000-120540.

Contents of the invention

Summary of the invention

A hermetic compressor includes a hermetic container, a motor element and a compression element. The shaft of the compression element has a main shaft portion, a flange portion protruding from the main shaft portion, and an eccentric shaft portion connected to the flange portion. The piston reciprocates in a first direction and a second direction opposite thereto in the compression chamber. The main bearing has a thrust surface on which the flange portion of the shaft abuts and slides. The thrust surface consists of two parts: a first part that is farther away from the compression chamber than the central axis in a direction parallel to the first direction, and a compression chamber that is closer to the central axis than the central axis in a direction parallel to the first direction Part 2 of the room. The area of the first portion of the thrust surface is larger than the area of the second portion.

The hermetic compressor has high efficiency and high reliability.

Description of drawings

Fig. 1 is a longitudinal sectional view of a hermetic compressor in Embodiment 1 of the present invention.

FIG. 2 is a plan view of a cylinder block of the hermetic compressor in Embodiment 1. FIG.

3 is a sectional view of main parts of the hermetic compressor in Embodiment 1. FIG.

4 is an enlarged cross-sectional view of a main part of a motor element of the hermetic compressor in Embodiment 1. FIG.

FIG. 5 shows changes in the reaction load with respect to the rotation angle in the hermetic-type compressor in Embodiment 1. FIG.

Fig. 6 is a longitudinal sectional view of a compression element of a hermetic compressor according to Embodiment 2 of the present invention.

7 is an exploded perspective view of a compression element of the hermetic compressor in Embodiment 2. FIG.

Fig. 8 is a longitudinal sectional view of a conventional hermetic compressor.

Fig. 9 is a plan view of a cylinder of a conventional hermetic compressor.

Detailed ways

(Embodiment 1)

Fig. 1 is a longitudinal sectional view of a hermetic compressor 1001 in Embodiment 1 of the present invention. The hermetic compressor 1001 includes an airtight container 101 , an electric element 105 arranged in the airtight container 101 , and a compression element 106 arranged in the airtight container 101 . The airtight container 101 is used to store lubricating oil 102 . The electric element 105 includes a stator 103 and a rotor 104 . The compression element 106 is attached above the electric element 105 and driven by the electric element 105 .

The shaft 110 constituting the compression element 106 includes: a main shaft part 111 extending along the central axis C111; a flange part (flange) 112 protruding from the main shaft part 111 away from the central axis C111; The eccentric shaft portion 113 extends from the upper surface 112A of the edge portion 112 . Central axis C111 extends along direction axis 1001A. In Embodiment 1, direction axis 1001A extends along the vertical direction. The main shaft portion 111 extends from the flange portion 112 in a direction 111C along the direction axis 1001A. In Embodiment 1, the direction 111C is directed downward in the vertical direction. The eccentric shaft portion 113 is provided at an eccentric position with respect to the main shaft portion 111, that is, the eccentric shaft portion 113 is parallel to the central axis C111 and extends along a central axis C113 different from the central axis C111, and is opposite to the direction 111C from the flange portion 112. The direction 111D extends. Direction 111D is directed upward in the vertical direction in Embodiment 1. FIG. The rotor 104 is shrinkfitted to the main shaft 111 . An oil supply mechanism 114 is provided inside the shaft 110 . A spiral oil supply groove 114A is provided on the surface of the shaft 110 . One end of the oil supply groove 114A communicates with the oil supply mechanism 114 , and the other end extends toward the lower surface 112B of the flange portion 112 .

In the cylinder block 115 constituting the compression element 106 , a substantially cylindrical compression chamber 116 extending on a direction axis 1001B perpendicular to the direction axis 1001A is formed. A main bearing 117 extending on the direction axis 1001A is provided in the cylinder block 115 . A shaft hole 117A through which the main shaft portion 111 of the shaft 110 passes is provided in the main bearing 117 . The shaft hole 117A extends along the central axis C117.

The piston 118 is inserted into the compression chamber 116 of the cylinder block 115 in a free reciprocating sliding manner on the direction axis 1001B. The piston 118 has a piston pin 120 extending parallel to the direction axis 1001A. The piston pin 120 , that is, the piston 118 is coupled to the shaft 110 by a coupling mechanism 119 . One end of the link mechanism 119 is rotatably inserted through the piston pin 120 , and the other end of the link mechanism 119 is rotatably inserted through the eccentric shaft portion 113 . Compression chamber 116 (piston 118 ) is located in direction 116A parallel to direction axis 1001B from center axis C111 .

An end surface 117C of the main bearing 117 in the cylinder block 115 has a flat, planar thrust surface 121 . The thrust surface 121 slides directly on the lower surface 112B of the flange portion 112, and the shaft 110 supports the load in the vertical direction due to the self-weight of the rotor 104 and the shaft 110 and the compression due to the piston 118 while the shaft 110 passes through the shaft hole 117A. The load in the vertical direction due to the influence of the load generated by the action. The thrust surface 121 directly slides with the lower surface 112B of the flange portion 112, thus constituting a thrust sliding portion.

FIG. 2 is a plan view of the thrust surface 121 of the cylinder block 115 of the hermetic compressor 1001 viewed from a direction 111C. FIG. 3 is a sectional view of main parts of the hermetic compressor 1001 . As shown in FIG. 2 , the thrust surface 121 completely surrounds the shaft hole 117A in the same plane as the thrust surface 121 , that is, the inner edge 121D of the thrust surface 121 completely surrounds the shaft hole 117A in the same plane as the thrust surface 121 . The outer edge 121C of the thrust surface 121 has a substantially perfect circular shape when viewed in a direction parallel to the direction axis 1001A ( FIG. 1 ). The center C121 of this perfect circle is located at an eccentric position shifted by a predetermined distance L11 in a restricted direction with respect to the center axis C117 of the shaft hole 117A. That is, the center C121 of the thrust surface 121 is shifted by a predetermined distance L11 from the central axis C117 in the direction 116B opposite to the direction 116A toward the compression chamber 116 .

The thrust width 124 of the thrust surface 121 is the distance between the inner edge 121D and the outer edge 121C in the radial direction centered on the central axis C117 . Among the thrust widths 124, the thrust width 124A in the direction 116A from the central axis C117 of the shaft hole 117A is the smallest, and the thrust width 124B in the direction 116B from the central axis C117 is the largest. That is, thrust width 124 is greatest in direction 116B away from compression chamber 116 . In this way, the area of the thrust surface 121 gradually increases in the direction away from the compression chamber 116 . In the directions 116A, 116B parallel to the direction axis 1001B, the area of the portion 121B of the thrust surface 121 in the direction 116B farther from the compression chamber 116 than the central axis C117 is compared to the direction closer to the compression chamber 116 than the central axis C117 Part 121A of thrust surface 121 of 116A has a large area.

At a position closest to the compression chamber 116 on the thrust surface 121 , an oil groove 127 extending parallel to a direction axis 1001B which is the axial direction of the compression chamber 116 is provided. Lubricating oil 102 sucked up from the lower portion of airtight container 101 by oil supply mechanism 114 and passed through oil supply groove 114A passes through oil groove 127 and mainly lubricates the sliding portion formed in thrust surface 121 and lower surface 112B of flange portion 112 .

The oil groove 127 is provided at the position closest to the compression chamber 116 so that a sliding area with the flange portion 112 of the shaft 110 is ensured at a portion 121B of the thrust surface 121 away from the compression chamber 116 .

The thrust surface 121 is subjected to nitriding treatment and ceramic coating treatment using ceramics such as CrN and TiN to process it into a surface with low friction and high hardness.

FIG. 4 is an enlarged sectional view of main parts of the electric element 105 of the hermetic compressor 1001 . The iron core of the stator 103 of the electric element 105 has a plurality of teeth, and constitutes a concentrated winding type electric element 105 having a winding wound on the plurality of teeth. The magnetic center 126 of the rotor 104 is shifted by a predetermined distance L12 in the direction 111C from the magnetic center 125 of the stator 103 . In Embodiment 1, the direction 111C is directed downward in the vertical direction.

The electric element 105 can operate at different rotation speeds according to inverter control. In the first embodiment, the rotation speed is usually 60 Hz, and the maximum rotation speed is set at 80 Hz.

The conventional hermetic compressor 500 shown in FIGS. 8 and 9 includes a compression element provided on the upper portion of the cylinder 9 as a support frame, and an electric element provided on the lower portion of the cylinder 9 . In the conventional hermetic compressor 500, the reaction force of the piston load controlled by the pressure in the cylinder 6 and the bore diameter is generated during compression. This reaction force acts as a load on the side of the crank pin 11 of the shaft 2 .

There is a gap of about 10 to 30 μm in the bearing portion 15 provided between the shaft 2 and the cylinder 9 . The shaft 2 is inclined, in contact with the cylinder 9 in the thrust slide and the journal slide. In the thrust sliding part, due to the influence of the piston load, the load greater than the self-weight of the shaft 2 and the rotor 3 acts as a load.

As can be seen from the above, in the compressor 500 including the compression element provided on the upper part of the cylinder 9 as a supporting frame and the electric element provided on the lower part of the cylinder 9, as thrust loads, the shaft 2 and the rotor 3 In addition to its own weight, the load of the piston 7 is also added, and the surface pressure of the thrust sliding part increases locally, so that so-called one-end contact tends to occur.

From this, it can be seen that in the hermetic compressor 500 , in order to reduce the locally increased surface pressure of the thrust sliding part, the sliding area of the entire thrust sliding part is ensured, and the local surface pressure of the thrust sliding part is prevented from increasing.

However, if the sliding area of the thrust sliding portion is increased, the sliding resistance in the thrust sliding portion will increase, so the sliding loss of the thrust sliding portion may increase and the efficiency may decrease.

Hereinafter, the action of hermetic compressor 1001 in Embodiment 1 will be described. The hermetic compressor 1001 is connected to a cooling system in which refrigerant gas circulates.

When the electric element 105 is energized, the rotor 104 rotates the shaft 110 , and at the same time, the rotational motion of the eccentric shaft portion 113 around the central axis C111 is transmitted to the piston pin 118 through the coupling mechanism 119 . As a result, the piston 118 reciprocates within the compression chamber 116 parallel to the direction axis 1001B.

According to the reciprocating motion of the piston 118, the refrigerant gas is sucked into the compression chamber 116 from the cooling system, compressed, and then sprayed out to the cooling system again.

Piston 118 is subjected to a reaction load F1 in direction 116B when compressing refrigerant gas in compression chamber 116 . As the shaft 110 rotates, on the entire surface of the thrust surface 121 formed on the upper end surface 117C of the cylinder block 115, as shown in FIG. The load F3 in the direction 111C acts on it. Simultaneously, on the thrust surface 121 , a load F2 which is a component force in a direction parallel to the direction axis 1001A due to the reaction load F1 acts locally. In the direct sliding between the lower surface 112B of the flange portion 112 provided on the shaft 110 and the thrust surface 121, the load F2 affects the sliding loss and the surface pressure depending on the size of the contact area between the lower surface 112B of the flange portion 112 and the thrust surface 121. make an impact.

FIG. 5 shows changes in the rotation angle reaction load F1 with respect to the compression stroke in the hermetic compressor 1001 . In FIG. 5 , the ordinate represents the magnitude of the reaction load F1 , and the abscissa represents the rotation angle of the shaft 110 . At a rotation angle of 0 degrees, the piston 118 is farthest from the central axis C111 in the direction 116A, compressing the refrigerant gas at the highest compression ratio. During the rotation of the shaft 110 from 0 to 180 degrees of rotation, the piston 118 performs a suction stroke of sucking refrigerant gas in the compression chamber 116, and during the rotation of the shaft 110 from 180 degrees of rotation to 360 degrees of rotation, A compression stroke that compresses the refrigerant gas is performed. 3 and 5 , load F2 in direction 111C (direction parallel to direction axis 1001A) acting locally on thrust surface 121 and caused by the influence of reaction load F1 of piston 118 will be described.

The reaction load F1 acting on the piston 118 is determined by the pressure in the compression chamber 116 and the inner diameter of the compression chamber 116 . In the compression stroke, the shaft 110 presses the piston 118 in the direction 116A. Therefore, as shown in FIG. 5 , the reaction load F1 becomes the maximum reaction load F1max not at the rotation angle of 360 degrees but at around 330 degrees in the second half of the compression stroke. , greatly acts on the shaft 110 through the coupling mechanism 119 .

In the second half of the compression stroke that generates the maximum reaction load F1max, the eccentric shaft portion 113 is located closer to the compression chamber 116 than the central axis C117 in the direction parallel to the direction axis 1001B, and the reaction load acting on the piston 118 F1 acts on the eccentric shaft portion 113 via the coupling mechanism 119 .

A gap of about 10 to 30 μm is provided between the diameter of the main shaft portion 111 of the shaft 110 and the diameter of the shaft hole 117A of the main bearing 117 . The reaction load F1 acts on the eccentric shaft portion 113 in the direction 116B. Due to the above clearance, inclination toward the central axis C117 of the shaft hole 117A occurs on the shaft 110 . Due to this inclination, on the center axis C117, in the region of the thrust surface 121 on the side substantially opposite to the compression chamber 116, the load F2, which is the component force of the reaction load F1 in the direction parallel to the direction axis 1001A, acts on the thrust surface. 121 on.

Therefore, the load F3 in the direction 111C due to the self-weight of the rotor 104 and the shaft 110 acts on the entire thrust surface 121, and the reaction load F1 is applied to the portion 121B on the side substantially opposite to the compression chamber 116 on the central axis C111. The load F2 in the direction 111C generated by the effect of the action.

By shifting the center C121 of the thrust surface 121 by a predetermined distance L11 from the central axis C117 of the shaft hole 117A, the thrust width 124 forming the thrust surface 121 becomes non-uniform throughout.

That is, the portion 121B of the thrust surface 121 (the portion farther from the compression chamber 116 than the central axis C117) that receives the load F2 in the vertical direction due to the influence of the reaction load F1 caused by the compression action of the piston 118 is locally increased. The thrust width 124B of the portion 121B) is such that the thrust width 124A of the portion 121A closer to the compression chamber 116 than the central axis C117 is smaller than the thrust width 124B. This suppresses an increase in the face pressure due to the load F2 acting locally on the thrust face 121 .

As a result, the sliding loss of the thrust sliding portion formed by the lower surface 112B of the flange portion 112 and the thrust surface 121 can be reduced. The efficiency and reliability of the hermetic compressor 1001 can be improved by preventing the surface pressure of the portion 121B receiving the load F2 from increasing and reducing partial wear of the thrust surface 121 . According to this structure, the area of the entire thrust surface 121 can be reduced, and the partial wear of the thrust surface 121 can be further reduced, thereby improving the efficiency and reliability of the hermetic compressor 1001 .

In addition, the amount of oil supplied to the thrust surface 121 from the oil groove 127 provided on the thrust surface 121 can be increased, and more lubricating oil 102 can lubricate the sliding portion of the thrust surface 121 . Providing the oil groove 127 in the portion 121A of the thrust surface 121 that is smaller than the thrust width 124 can ensure a sliding area with the lower surface 112B of the flange portion 112 on the side where the surface pressure largely acts, and can prevent the surface pressure from increasing. . As a result, the lubrication state of the sliding portion of the thrust surface 121 can be improved, and the reliability of the hermetic compressor 1001 can be further improved.

The thrust surface 121 is subjected to nitriding treatment and ceramic coating treatment using ceramics such as CrN and TiN. Therefore, the thrust surface 121 becomes a surface with less friction and high hardness, and the friction between the lower surface 112B of the flange portion 112 and the sliding surface can be further reduced. 121 Sliding resistance when contact sliding. Therefore, the sliding loss of the thrust sliding portion can be further reduced to improve efficiency, and the wear resistance of the thrust sliding portion can be improved by increasing the surface hardness of the thrust surface 121 .

By processing the thrust surface 121 with less friction and high hardness, the area acting on the sliding of the entire thrust surface 121 can be further reduced to achieve less friction.

Thrust surface 121 is inclined so that portion 121B where load F2 acts in direction 111C is offset in direction 111C from portion 121A close to compression chamber 116 to become lower. That is, thrust surface 121 is inclined toward direction 111C along direction 116B. In this way, the entire lower surface 112B of the flange portion 112 can be brought into contact with the entire surface of the thrust surface 121 . As a result, not only can one end contact of the thrust sliding portion be further avoided, but also local surface pressure increase can be prevented, and partial wear of the thrust sliding portion can be suppressed.

In the electric element 105, the magnetic center 126 of the rotor 104 is shifted in the direction 111C with respect to the magnetic center 125 of the stator 103, so due to the magnetic attraction force, the shaft 110 fixed on the rotor 104 is directed upward in the direction 111D. lifting effect. As a result, the load F3 in the vertical direction 111C due to the self-weight of the rotor 104 and the shaft 110 during rotation is reduced. In this way, the surface pressure of the thrust surface 121 is reduced, so that the high reliability of the hermetic compressor 1001 can be obtained.

As described above, the hermetic compressor 1001 includes the hermetic container 101 , the electric element 105 and the compression element 106 . The electric element 105 has a stator 103 and a rotor 104 and is installed in the airtight container 101 . The compression element 106 is driven by the electric element 105 and is disposed in the airtight container 101 . The compression element 106 has a shaft 110 , a cylinder block 115 , a piston 118 , a coupling mechanism 119 , and a main bearing 117 . Shaft 110 has main shaft portion 111 extending along central axis C111 , flange portion 112 protruding from main shaft portion 111 , and eccentric shaft portion 113 connected to flange portion 112 , and rotor 104 is fixed thereto. The cylinder block 115 has a compression chamber 116 located in a direction 116A from a central axis C111 of the main shaft portion 111 to a direction 116A perpendicular to the central axis C111 . Piston 118 reciprocates within compression chamber 116 in a direction 116A and a direction 116B opposite to direction 116A. The connecting mechanism 119 connects the piston 118 and the eccentric shaft portion 113 . A shaft hole 117A for pivotally supporting the main shaft portion 111 of the shaft 110 is formed in the main bearing 117 . The main bearing 117 has a thrust surface 121 that surrounds the shaft hole 117A and on which the flange portion 112 of the shaft 110 abuts and slides. Thrust surface 121 consists of two parts: part 121B farther from compression chamber 116 than central axis C111 in directions 116A, 116B parallel to direction 116A, and part 121A closer to compression chamber 116 than central axis C111. Portion 121B of thrust surface 121 has a larger area than portion 121A.

Thrust surface 121 supports load F3 in vertical direction 111C due to the weight of rotor 104 and shaft 110 and load F2 in direction 111C that is a component force of reaction load F1 due to compression of piston 118 .

The lubricating oil 102 is stored in the airtight container 101 . An oil groove 127 communicating with the shaft hole 117A and through which the lubricating oil 102 passes is provided on the thrust surface 121 . The oil groove 127 is disposed on the portion 121A of the thrust surface 121 . Oil groove 127 extends from central axis C111 along straight line L101 extending in direction 1116A.

The main shaft portion 111 of the shaft 110 extends from the flange portion 112 in a direction 111C at right angles to the direction 116A. Thrust surface 121 is inclined toward direction 111C along direction 116B.

Magnetic center 126 of rotor 104 of motor element 105 is offset in direction 111C relative to magnetic center 125 of stator 103 . Magnetic center 126 of rotor 104 is located below magnetic center 125 of stator 103 .

In Embodiment 1, the compression element 106 is attached to the upper portion of the electric element 105 . However, the same effect can also be obtained by disposing the compression element 106 under the electric element 105 .

(Embodiment 2)

Fig. 6 is a longitudinal sectional view of a compression element of a hermetic compressor 1002 according to Embodiment 2 of the present invention. FIG. 7 is an exploded perspective view of the compression element of the hermetic compressor 1002 . In FIGS. 6 and 7 , the same reference numerals are assigned to the same parts as those of hermetic compressor 1001 in Embodiment 1 shown in FIGS. 1 to 4 .

Hermetic compressor 1002 in Embodiment 2 further includes annular thrust bearing 210 constituting thrust surface 121 in hermetic compressor 1001 in Embodiment 1.

In hermetic compressor 1002 , recessed portion 200 surrounding shaft hole 117A is provided on end surface 117C of main bearing 117 constituting cylinder block 115 . A thrust bearing 210 is fitted into the concave portion 200 . The main bearing 117 is composed of a radial bearing 117R having a shaft hole 117A and a thrust bearing 210 .

The concave portion 200 has a substantially perfect circular shape. The support surface 201 serving as the bottom of the concave portion 200 surrounds the shaft hole 117A and supports the thrust bearing 210 . The width of the support surface 201 gradually increases from the direction 116A toward the compression chamber 116 to the opposite direction 116B. A small recess 202 extending outward is provided in a part of the periphery of the recess 200 .

The outer edge 210C of the thrust bearing 210 has a substantially perfect circular shape. Thrust bearing 210 has the same shape as thrust surface 121 in Embodiment 1, and has thrust surface 213 having the same function. The thickness of the bearing 210 is set so that the thrust surface 213 slightly protrudes from the recess 200 in the direction 111D in a state where the thrust bearing 210 is fitted into the recess 200 . The center C211 of the through hole 211 provided in the central portion of the thrust bearing 210 coincides with the central axis C117 of the shaft hole 117A. On a part of the outer circumference of the thrust bearing 210 , a convex portion 212 that fits into the small concave portion 202 provided in the concave portion 200 is provided.

As described above, main bearing 117 has radial bearing 117R and thrust bearing 210 . A shaft hole 117A is formed in the radial bearing 117R. The thrust bearing 210 has a thrust surface 121 and is formed separately from the radial bearing 117R.

Thrust bearing 210 is fixed by fitting of small concave portion 202 and convex portion 212 .

As in the first embodiment, at least the thrust surface 213 of the thrust bearing 210 is subjected to nitriding treatment and ceramic coating treatment with ceramics such as CrN and TiN to have a low-friction and high-strength surface.

The thrust face 213 is formed by portions 213A, 213B. Portion 213A is closer to compression chamber 116 than central axis C111 (center C211 ). Portion 213B is farther from compression chamber 116 than central axis C111 (center C211 ). By adjusting the thickness of the thrust bearing 210 or processing the support surface 201 of the concave portion 200, the thrust surface 213 is inclined so that the portion 213B of the thrust surface 213 is offset in the direction 111D relative to the portion 213A.

On a part of the thrust surface 213 of the thrust bearing 210 , an oil groove 214 having the same function as the oil groove 127 in Embodiment 1 is provided along the radial direction of the through hole 211 . In Embodiment 2, the oil groove 214 is provided at a position closest to the compression chamber 116 on the thrust surface 213 , that is, along the direction 116A from the center C211 .

The lubricating oil sucked up from the lower part of the airtight container 101 by the oil supply mechanism 114 and passed through the oil supply groove 114A passes through the oil groove 214 to the thrust sliding part formed on the thrust surface 213 and the lower surface 112B of the flange part 112, mainly lubricating the thrust sliding part. .

Next, the operation of the hermetic compressor 1002 in Embodiment 2 will be described. As in the hermetic compressor 1001 in Embodiment 1, when the electric element 105 is energized, the rotor 104 rotates, and the compression element 106 operates accordingly. As a result, the refrigerant gas is sucked into the compression chamber 116 from the cooling system, compressed, and discharged toward the cooling system again.

In the hermetic compressor 1002 according to Embodiment 2, along with the rotation of the shaft 110, on the thrust surface 213 of the thrust bearing 210 of the main bearing 117, due to the self-weight of the rotor 104 and the shaft 110 shown in FIG. 6 The load F3 in the vertical direction 111C acts fully thereon. At the same time, a load F2 that is a component force in the vertical direction 111C of the reaction load F1 generated by the compressive action of the piston 118 locally acts on the portion 213B of the thrust face 213 .

In the direct sliding between the lower surface 112B of the flange portion 112 provided on the shaft 110 and the thrust surface 213 of the thrust bearing 210 , according to the contact as the area of the portion where the lower surface 112B of the flange portion 112 and the thrust surface 213 contact The size of the area and the load F2 affect the sliding loss and surface pressure. In the directions 116A, 116B parallel to the direction axis 1001B, a portion 213B of the thrust surface 213 of the compression chamber 116 farther from the center C211 is a region where the load F2 is locally received. Similar to the hermetic compressor 1001 in Embodiment 1, in the hermetic compressor 1002, the area of the portion 213B, that is, the thrust width 215 is set to be smaller than the area of the portion 213A, that is, the thrust width, that is closer to the compression chamber 116 than the center C211. 215 large. In this way, it is possible to suppress an increase in the face pressure due to the load F2 locally acting on the thrust face 213 .

As a result, similar to the first embodiment, the sliding loss of the thrust sliding portion formed by the lower surface 112B of the flange portion 112 and the thrust surface 213 of the thrust bearing 210 can be reduced. Preventing the surface pressure of the part 213B partially bearing the load F2 from increasing can reduce the partial wear of the thrust surface 213 and improve the efficiency and reliability of the hermetic compressor 1002 .

With the oil groove 214 provided on the thrust surface 213 of the thrust bearing 210 , the amount of oil supplied from the oil groove 214 to the thrust surface 213 can be increased, and more lubricating oil 102 lubricates the sliding portion of the thrust surface 213 . In the thrust surface 213, disposing it in the smaller portion 213A of the thrust width 215 can securely increase the sliding area of the portion 213B on which the face pressure largely acts, and can prevent the face pressure from increasing. As a result, the lubrication state of the sliding portion of the thrust surface 213 of the thrust bearing 210 can be improved, and the reliability of the hermetic compressor 1002 can be further improved.

By performing nitriding treatment and ceramic coating treatment using ceramics such as CrN and TiN, the thrust surface 213 becomes a surface with less friction and high strength, and the occurrence of sliding between the lower surface 112B of the flange portion 112 and the thrust surface 213 can be further reduced. of sliding resistance. Therefore, the sliding loss of the thrust sliding portion formed by the lower surface 112B of the flange portion 112 and the thrust surface 213 can be further reduced to improve efficiency, and the wear resistance of the thrust sliding portion can be improved by increasing the surface hardness of the thrust surface 213 .

By processing the thrust surface 213 with less friction and high hardness, the area acting on the sliding of the entire thrust surface 213 in the thrust bearing 210 can be further reduced to achieve low friction.

The thrust bearing 210 is another component separate from the main bearing 117 (radial bearing 117R), and therefore can be processed separately from the main bearing 117 . Therefore, the nitriding treatment and the ceramic coating treatment performed on the thrust surface 213 can be easily performed, and the thrust surface 213 can be easily processed so that the thrust surface 213 is inclined in the direction 111C along the direction 116B.

As a result, the degree of ceramic coating treatment can be easily adjusted and set at low cost, and the inclination of thrust surface 213 can be easily processed, so thrust bearing 210 can also be adapted to compressors with different compression capacities.

In Embodiment 2, the structure of the thrust surface 213 can also be applied to the hermetic compressor in which the compression element 106 is provided below the electric element 105, and the same effect can be obtained.

The hermetic compressors 1001 and 1002 in Embodiments 1 and 2 can be applied to refrigerating equipment such as air conditioners and refrigerating apparatuses because the sliding loss of the thrust sliding portion is reduced and high reliability is obtained.

The present invention is not limited to Embodiments 1 and 2.

Claims (10)

1. A hermetic compressor, characterized in that, comprising: sealed container; an electric element having a stator and a rotor and disposed within said airtight container; and a compression element driven by the electric element and arranged in the airtight container, The compression element has: a shaft having a main shaft portion extending along a central axis, a flange portion protruding from the main shaft portion, and an eccentric shaft portion connected to the flange portion, and the rotor is fixed to the shaft; a cylinder block having a compression chamber located in a first direction from the central axis of the main shaft portion at a right angle to the central axis; a piston reciprocating in the compression chamber in the first direction and in a second direction opposite to the first direction; a coupling mechanism coupling the piston to the eccentric shaft portion; and a main bearing having a shaft hole for supporting the main shaft portion of the shaft and having a thrust surface surrounding the shaft hole on which the flange portion of the shaft comes into contact and slides, The thrust surface includes: a first portion farther from the compression chamber than the central axis in a direction parallel to the first direction; and a first portion closer to the compression chamber than the central axis. 2 parts, The area of the first portion of the thrust surface is larger than the area of the second portion. 2. The hermetic compressor according to claim 1, characterized in that: The thrust surface supports a vertical load due to the weight of the rotor and the shaft, and a vertical component force of a reaction load due to the compression action of the piston. 3. The hermetic compressor according to claim 1, characterized in that: configured to store lubricating oil in said airtight container, An oil groove that communicates with the shaft hole through which the lubricating oil passes is provided on the thrust surface. 4. The hermetic compressor according to claim 3, characterized in that: The oil groove is provided on the second portion of the thrust surface. 5. The hermetic compressor according to claim 4, characterized in that: The oil groove extends from the central axis along a straight line extending in the first direction. 6. The hermetic compressor according to claim 1, characterized in that: the main shaft portion of the shaft extends from the flange portion in a third direction at right angles to the first direction, The thrust surface is inclined toward the third direction along the second direction. 7. The hermetic compressor according to claim 1, characterized in that: Nitriding treatment and ceramic coating treatment are carried out on the thrust face. 8. The hermetic compressor according to claim 1, characterized in that: The main bearing has: a radial bearing formed with said shaft hole; and A thrust bearing having the thrust surface and being provided separately from the radial bearing. 9. The hermetic compressor according to claim 1, characterized in that: the main shaft portion of the shaft extends from the flange portion in a third direction at right angles to the first direction, A magnetic center of the rotor of the motor element is offset in the third direction from a magnetic center of the stator. 10. The hermetic compressor according to claim 9, characterized in that: The magnetic center of the rotor is located below the magnetic center of the stator.

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