CN107795459A - Compressor and the refrigerator for possessing the compressor - Google Patents

Abstract

The present invention provides a compressor that effectively increases the amount of oil supplied while suppressing the height dimension, and a refrigerator equipped with the compressor. The compression unit (20) has: a cylinder (21); a piston (22) that reciprocates in the cylinder (21) to compress the refrigerant; a crankshaft (23) that rotates eccentrically by the electric unit (30); The eccentric portion (23p) of the crankshaft (23) is rotatably connected to the connecting rod (25) of the piston (22); the piston pin (29) is rotatably connected to the piston (22) and the connecting rod (25); and the shaft supports the crankshaft In the radial bearing (26) of (23), the thickness of the flange portion (23b) protruding radially from the upper end of the main shaft (23a) of the crankshaft (23) is 4mm or less.

Description

Compressor and Refrigerator Equipped with the Compressor

technical field

The present invention relates to a compressor and a refrigerator provided with the compressor.

Background technique

A reciprocating compressor has a mechanism for compressing refrigerant by reciprocating a piston by rotating a crankshaft eccentrically with the power of an electric motor. In addition, in recent years, along with the improvement in power saving (efficiency) of refrigerators, the efficiency of compressors has also been similarly increased. Therefore, the compressor can operate in a wide range from a low operating frequency lower than the commercial power supply frequency to a high frequency higher than the commercial power supply frequency. If the compressor is operated at a low operating frequency for a long period of time, power will be saved during this part of the time. Therefore, operating the compressor at a low speed is extremely important for power saving of the refrigerator. However, if the compressor is operated at a low speed, the amount of lubricating oil supplied between the cylinder and the piston may decrease. Therefore, Patent Document 1 and the like are proposed as a technology capable of efficiently supplying lubricating oil even during low-speed operation.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2015-206269

Contents of the invention

The problem to be solved by the invention

However, in the technique described in Patent Document 1, it is difficult to effectively increase the oil supply amount while suppressing the overall height of the compressor.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a compressor and a refrigerator provided with the compressor that effectively increase the oil supply amount while suppressing the height dimension.

Solution to the problem

The present invention is a compressor comprising: a compression unit; an electric unit for driving the compression unit; and a container for accommodating the compression unit and the electric unit. The compressor is characterized in that the compression unit has: a cylinder; A piston that reciprocates inside to compress the refrigerant; a crankshaft that rotates eccentrically by the electric unit; a rod that rotatably connects the eccentric portion of the crankshaft to the piston; and a bearing that supports the crankshaft. The thickness of the radially protruding flange portion at the upper end is 4 mm or less.

Invention effect

ADVANTAGE OF THE INVENTION According to this invention, the compressor which suppressed height dimension and increased the oil supply quantity effectively, and the refrigerator provided with the compressor can be provided.

Description of drawings

FIG. 1 is a longitudinal sectional view showing a compressor according to this embodiment.

Fig. 2 is a cross-sectional view showing the compressor of the present embodiment.

FIG. 3 is an explanatory diagram showing the positional dimensions of each inclination angle based on the gap when calculating the interference factor of the compressor.

Fig. 4 is a graph showing the relationship between interference ratio and COP.

Fig. 5 is a graph showing the relationship between the interference ratio and the main axis length/rod pitch.

Fig. 6 is a schematic sectional view of a refrigerator equipped with a compressor according to the present embodiment, (a) is a structure in which the compressor is arranged in the lower part, and (b) is a structure in which the compressor is arranged in the upper part.

In the picture:

3—airtight container, 9—coil spring, 10—rubber seat, 20—compression unit, 21—cylinder, 22—piston, 23—crankshaft, 23a—main shaft, 23b—flange, 23p—eccentric portion, 24— Frame, 24a—base, 24b—through hole, 24c—recess, 24d—extrusion, 25—connecting rod (rod), 25a—small end, 25a1—connecting hole, 25b—large end, 25b1—connecting hole , 26—radial bearing (bearing), 27—thrust bearing, 28—top cover, 29—piston pin, 30—electric unit, 31—rotor, 32—stator, 100—compressor, A～E—inclination angle , H—the height of the small end, L—the length of the main shaft, P—the distance between the rods, Q2—the side of the compressor room, Q3—the opposite side of the compressor room.

Detailed ways

Hereinafter, compressor 100 according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing a compressor according to this embodiment.

As shown in FIG. 1 , the compressor 100 is a so-called reciprocating compressor configured by arranging a compression unit 20 and an electric unit 30 in an airtight container 3 . The compression unit 20 and the electric unit 30 are elastically supported in the airtight container 3 via a plurality of coil springs 9 (elastic members). The airtight container 3 has an upper case 3m constituting a roughly upper half outline and a lower case 3n constituting a substantially lower half contour by welding or the like, and has a space for accommodating the compression unit 20 and the electric unit 30 inside.

The compression unit 20 is configured to include: a cylinder 21; a piston 22 that reciprocates in the cylinder 21 to compress the refrigerant; a crankshaft 23 (crankshaft) that is eccentrically rotated by the electric unit 30; and an eccentric portion that connects the crankshaft 23. 23p and connecting rod 25 (rod) of piston 22; radial bearing 26 (bearing) and thrust bearing 27 (bearing) supporting crankshaft 23.

The cylinder tube 21 is formed at a radially outward position relative to the central axis O of the crankshaft 23 (main shaft 23 a ). In addition, the axial direction O1 of the cylinder tube 21 is configured to be a direction perpendicular to the axial direction (central axis O) of the crankshaft 23 . In addition, a top cover 28 is attached to an end portion on the outer peripheral side in the axial direction O1 of the cylinder tube 21 , and a piston 22 is inserted into an end portion on the opposite side. Thus, the compression chamber (cylinder chamber) Q1 is comprised by the cylinder 21, the piston 22, and the top cover 28. As shown in FIG. In addition, a valve opening and closing mechanism (not shown) is provided between the cylinder 21 and the top cover 28. The valve opening and closing mechanism includes an intake valve that is opened when refrigerant is absorbed, and a valve that is opened when the compressed refrigerant is discharged. Open discharge valve.

The piston 22 is coupled to a small end 25 a (end on the side of the piston 22 ) of the connecting rod 25 via a piston pin 29 . That is, the piston 22 is formed with a connection hole 22 a penetrating in the vertical direction and a recess 22 b into which the small end portion 25 a of the connecting rod 25 is inserted.

The crankshaft 23 includes a main shaft 23a, a flange portion 23b protruding radially from the upper end of the main shaft 23a, and an eccentric portion 23p formed at a position deviated from the central axis O of the main shaft 23a. The central axis O of the main shaft 23a is set parallel to the rotational central axis of the eccentric portion 23p. In addition, the lower end portion of the crankshaft 23 extends to the vicinity of the lower housing 3n. The eccentric portion 23p rotates eccentrically with respect to the central axis O, so that the piston 22 reciprocates within the cylinder 21 .

The main shaft 23 a has a cylindrical shape extending in the vertical direction, and is rotatably supported by a radial bearing 26 . In addition, the central axis O (axial direction) of the main shaft 23 a is configured to be parallel to the axial direction of the radial bearing 26 .

The flange portion 23b is configured to also serve as a counterweight. The counterweight has a function of reducing vibration when the compression unit 20 is driven. Therefore, by positioning the counterweight between the main shaft 23a and the eccentric portion 23p, the height dimension of the compression unit 20 can be reduced, which can contribute to downsizing of the compressor 100 .

In addition, the main shaft 23a of the crankshaft 23 is configured such that a concave bore 23c is formed upward from the lower end surface in the axial direction, and a hollow portion is provided in the main shaft 23a. In addition, an upper communication hole 23 d penetrating from the upper end of the bore hole 23 c toward the upper surface of the flange portion 23 b is formed in the crankshaft 23 . In addition, on the outer peripheral surface of the crankshaft 23, a spiral groove 23e is formed up to the vicinity of the flange portion 23b.

In the eccentric portion 23p, a concave bore 23f is formed downward from the upper end surface in the axial direction. The depth of the bore hole 23f from the upper surface is formed to be shorter than the axial length of the eccentric portion 23p. In addition, the bore hole 23f communicates with the upper end portion of the spiral groove 23e via the communication hole 23g.

A fixed shaft member 23h is inserted into the hollow portion of the main shaft 23a. The fixed shaft member 23h is fixed by the stator 23i so as not to rotate even when the crankshaft 23 rotates. A fixed shaft spiral groove 23j is formed on the outer peripheral surface of the fixed shaft member 23h. A spiral lubricating oil passage is formed by the wall surface of the fixed shaft helical groove 23j and the wall surface of the bore hole 23c, and the lubricating oil is dragged to the wall surface by the effect of viscosity as the wall surface moves due to the rotation of the crankshaft 23 (main shaft 23a). , and rise in the fixed shaft helical groove 23j.

The frame 24 has a base 24a extending substantially in the horizontal direction, and the cylinder 21 is located on the upper portion of the base 24a. In addition, a cylindrical radial bearing 26 extending vertically downward (toward the bottom surface of the lower case 3 n ) is formed at a substantially central portion of the frame 24 . In addition, the frame 24 constitutes a part of the cylinder 21 .

The connecting rod 25 (rod) is a member connecting the piston 22 and the crankshaft 23, and has a small end 25a and a large end 25b (the end on the eccentric portion 23p side). In the small end portion 25a, a circular connection hole 25a1 through which the piston pin 29 is inserted is formed penetratingly in the up-down direction. In the large end portion 25b, a circular connection hole 25b1 through which the eccentric portion 23p is inserted is formed penetratingly in the vertical direction.

The axial direction of the coupling hole 25 a 1 of the small end portion 25 a is configured to be parallel to the axial direction of the piston pin 29 . The axial direction of the connecting hole 25b1 of the large end portion 25b is configured to be parallel to the axial direction of the eccentric portion 23p.

The radial bearing 26 is constituted by a sliding bearing that pivotally supports the main shaft 23 a of the crankshaft 23 . In addition, the radial bearing 26 has a through hole 26 b penetrating in the vertical direction. In addition, the radial bearing 26 supports a part of the main shaft 23a. That is, the upper end 26a of the radial bearing 26 is positioned substantially at the lower end of the flange portion 23b, and the lower end 26c of the radial bearing 26 is positioned substantially at the center in the height direction of the bore 23c.

The thrust bearing 27 is disposed in a recess 24c formed in a circular groove shape at the opening edge of the through hole 26b of the base 24a. The thrust bearing 27 is composed of a set of rail plates 27a, 27b, a cage 27c, and rolling elements 27d. The thrust bearing 27 is disposed between the flange portion 23b of the crankshaft 23 and the recessed portion 24c.

The rail plate 27a located on the lower side has a ring shape, and is arrange|positioned so that it may contact the bottom surface 24c1 of the recessed part 24c. The rail plate 27b located on the upper side has a ring shape, and is arrange|positioned so that it may contact the lower surface 23b1 of the flange part 23b.

The piston pin 29 is inserted through both the connection hole 22a of the piston 22 and the connection hole 25a1 of the small end portion 25a, thereby rotatably connecting the piston 22 and the connecting rod 25 . In addition, the axial direction (vertical direction in the drawing) of the piston pin 29 is configured to be parallel to the axial direction of the connecting hole 22 a of the piston 22 .

The lubricating oil (refrigerator oil) that has risen through the bore hole 23c emerges onto the flange portion 23b through the upper communication hole 23d, and lubricates the thrust bearing 27. In addition, the lubricating oil ascending the helical groove 23e of the crankshaft 23 lubricates between the crankshaft 23 (main shaft 23a) and the radial bearing 26, flows into the bore 23f of the eccentric portion 23p through the communication hole 23g, and acts on the connecting rod 25. Lubricate around. In addition, the lubricating oil which lubricated the thrust bearing 27 etc. is comprised so that it may return to the bottom part of the airtight container 3 through the hole 24s (refer FIG. 2) formed in the frame 24. As shown in FIG.

The electric unit 30 is arranged on the lower side of the frame 24 (below the base 24 a ), and includes a rotor 31 and a stator 32 .

The rotor 31 includes a rotor core formed by laminating electromagnetic steel sheets, and is fixed to the lower portion of the crankshaft 23 (main shaft 23 a ) by press fitting or the like. In addition, the rotor 31 has a flat shape having a radius R larger than a thickness (height in the axial direction) T1. In addition, the thickness (height in the axial direction) T1 of the rotor 31 is set to approximately half the length (bearing length) of the radial bearing 26 .

The stator 32 is configured to be disposed on the outer periphery of the rotor 31, and includes: a cylindrical stator core and an iron core 32a formed with a plurality of slots formed on the inner periphery of the stator core; and an insulator (not shown) shown) coil 32b wound around iron core 32a. In addition, in the longitudinal sectional view of FIG. 1 , the iron core 32 a has a flat shape in which the length L1 in the radial direction is longer than the thickness (height in the axial direction) T2. The coil 32b also has a flat shape in which the length in the radial direction is longer than the thickness (height in the axial direction) in the longitudinal sectional view of FIG. 1 . In addition, the thickness (height in the axial direction) T2 of the iron core 32 a is configured to be approximately the same as the thickness (height in the axial direction) T1 of the rotor 31 . Therefore, when the rotor 31 is formed flat, the diameter of the stator 32 is also expanded to form a flat shape, whereby torque for rotating the rotor 31 can be obtained.

Then, the frame 24 provided with the compression unit 20 and the electric unit 30 is elastically supported in the airtight container 3 via a plurality of coil springs 9 , 9 . In addition, the compression unit 20 and the electric unit 30 are designed so that a predetermined clearance CL is preset so as not to contact the inner wall surface of the airtight container 3 when vibration occurs during operation.

The coil spring 9 is provided on the side of the cylinder 21 constituting a part of the compression unit 20 (compressor chamber side Q2, left side in FIG. to the right of the ). In addition, in the present embodiment, the coil spring 9 is provided on the near side and the deep side in the direction perpendicular to the paper surface of FIG. It is supported by a total of four coil springs 9 (see FIG. 2 ). Furthermore, all coil springs 9 have the same shape and spring characteristics. Therefore, by setting the coil spring 9 as a single type, it is possible to prevent an arrangement error when different types of coil springs 9 are mixed. However, the number of coil springs 9 is not limited to four, but may be three, or five or more.

In addition, the frame 24 has a protruding portion 24d extending on the outer peripheral side (radially outer side) of the cylinder tube 21 . The protruding portion 24d extends to the outer peripheral side of the stator 32 . Moreover, the protrusion part 24e which fits and holds the upper part of the coil spring 9 is formed in the lower surface of the extension part 24d.

Moreover, the frame 24 also has the extension part 24f extended to the same extent as the extension part 24d on the side opposite to the extension part 24d. The protruding portion 24f also extends to the outer peripheral side of the stator 32 . Moreover, the protrusion part 24g which fits and holds the upper part of the coil spring 9 is formed in the lower surface of the extension part 24f.

On the bottom surface of the airtight container 3 , a stepped portion 3 a protruding into the airtight container 3 is formed on the outer peripheral side of the stator 32 . A part of the bottom surface and a part of the side surface of the lower case 3n are closed, and the outer surface has a concave shape, thereby constituting the stepped portion 3a. In addition, the stepped portion 3 a is provided at a position corresponding to the position of the coil spring 9 . Moreover, the protrusion part 3b which holds the lower part of the coil spring 9 in a fitting manner is formed in the upper end surface of the stepped part 3a. The protrusion 3 b is located above the lower surface 31 a of the rotor 31 . In addition, the oil surface 40 of the lubricating oil is configured to be located below the lower surface 31 a of the rotor 31 so that the lubricating oil does not impregnate the rotor 31 . In addition, the lower end of the crankshaft 23 (main shaft 23 a ) and the lower end of the fixed shaft member 23 h are positioned below the oil surface 40 .

Fig. 2 is a cross-sectional view showing the compressor of the present embodiment. In addition, in FIG. 2 , the flow of the refrigerant in the compressor 100 will be described.

As shown in FIG. 2 , the refrigerant introduced from the cooler 66 (refer to FIG. 6 ) of the refrigerator and introduced from the suction pipe 3 e penetratingly connected to the airtight container 3 is sucked in from the suction port (not shown) of the suction muffler 41 . Then, it is introduced into the compression chamber Q1 via the top cover 28 and the like (see FIG. 1 ). In addition, the refrigerant compressed by the piston 22 in the compression chamber Q1 passes through the discharge chamber space (not shown), then passes through the discharge mufflers 42a, 42b and the pipe 3f formed on the frame 24, and passes through the condenser ( not shown), a decompression device (not shown) and sent to the cooler 66 (see FIG. 4 ).

In the compressor 100 thus constituted, the compression unit 20 is disposed on the upper portion of the frame 24 and the motor unit 30 is disposed on the lower portion, and the frame 24 is elastically supported in the airtight container 3 via the coil springs 9 , 9 . In this case, since the center of gravity is located at the height of the frame 24 (at the same level as the upper ends of the coil springs 9, 9), the deflection angle of the internal mechanism including the compression unit 20 and the electric unit 30 can be reduced. Moreover, by arranging the position of the coil spring 9 on the outer peripheral side of the cylinder tube 21, the vibration of the said internal mechanism part can be suppressed more effectively. Therefore, the vibration of the internal mechanism part can be suppressed, and the gap CL between the internal mechanism part (the compression unit 20 and the electric unit 30 ) and the airtight container 3 can be reduced (see FIG. 1 ). As a result, the airtight container 3 can be reduced in size, and the compressor 100 can be downsized.

Moreover, the rubber seat 10 (refer FIG. 1) elastically supporting the airtight container 3 is provided in the lower part of each step part 3a. The rubber seat 10 is supported by a plate 11 fixed to the lower case 3 n of the airtight container 3 . In addition, the rubber seat 10 is disposed at a position overlapping the coil spring 9 in the vertical direction (vertical direction). Forming the stepped portion 3a in this way, disposing the coiled spring 9 on the stepped portion 3a, the coiled spring 9 can be set at a height that is not impregnated with lubricating oil, therefore, the noise generated when the coiled spring 9 vibrates in the lubricating oil can be prevented, and the Calming of compressor 100 . In addition, by arranging the rubber seat 10 at the lower portion of the stepped portion 3a, it is possible to prevent the rubber seat 10 from protruding greatly downward from the lower case 3n of the airtight container 3, so that the height of the compressor 100 can be suppressed and compression can be achieved. Machine 100 miniaturization.

Here, the configuration of the crankshaft 23 for effectively increasing the oil supply amount while suppressing the overall height of the compressor 100 will be described. First, the inventors thinned each part of the components of the compressor 100 and repeatedly tested whether there was no problem in terms of strength, and found that there is room for thinning the flange portion 23b. Furthermore, it has been found that the lubrication supplied between the cylinder 21 and the piston 22 can be effectively increased by reducing the thickness of the flange portion 23b, which is currently about 7 to 9 mm, to less than 4 mm (preferably 2 mm to 3 mm). amount of oil. Hereinafter, the principle will be described.

When the thickness of the flange portion 23b is reduced, the cylinder 21 as a whole can be moved to a lower position without reducing the cross-sectional area of the cylinder 21 . That is, the distance between the bottom surface position (S in FIG. 1 ) of the thrust bearing 27 and the axial center position (O1 in FIG. 1 ) of the cylinder 21 can be reduced. As a result, the height of the upper end of the cylinder tube 21 is lowered, so that the lubricating oil splashed from the bore 23f easily reaches the upper surface of the piston 22 . In particular, the compressor 100 of this embodiment uses an inverter drive circuit to control the rotational speed in the range of, for example, 800 to 4300 rpm, and can ensure the amount of oil supplied even at a low speed of 800 rpm, so that both reliability and efficiency can be achieved. high compressor. In addition, since the cylinder 21 as a whole can be installed at a low position, the height dimension of the compressor 100 as a whole is also reduced (130 mm or less). Furthermore, by reducing the distance between the cylinder tube 21 and the thrust bearing 27, the load due to the moment applied to the main shaft 23a can be reduced, and there is also an effect of suppressing wear of the main shaft 23a.

Here, if the eccentricity of the crankshaft 23 (the distance between the axial center position of the main shaft 23a and the axial center position of the eccentric portion 23p ) is large, the flange portion 23b needs to be thickened to maintain strength. However, if the eccentricity of the crankshaft 23 is set to 9 mm or less, it will be easy to reduce the thickness of the flange portion 23 b as described above.

Next, a method of determining the relationship between the rod pitch P and the main shaft length L of the compressor 100 will be described with reference to FIGS. 3 to 5 . 3 is an explanatory diagram showing the positional dimensions of each inclination angle based on the gap when obtaining the interference factor in the compressor, FIG. 4 is a graph showing the relationship between the interference factor and COP, and FIG. 5 is a graph showing the relationship between the interference factor and the main axis length/ Diagram of the relationship between rod spacing. In addition, FIG. 3 schematically shows the inclination angle based on each gap for easy understanding.

In addition, an interference rate can be mentioned as one of the main factors for determining the COP (Coefficient Of Performance) of the compressor. This interference factor can be obtained by the following formula (1). In addition, in the description of the following formula (1), a crankshaft is called a shaft, a connecting rod is called a rod, and a cylinder tube and a radial bearing are called a frame. In addition, α, β, γ, and δ (none of them are shown) are inclination angles based on geometric tolerances, and A, B, C, D, and E are inclination angles based on gaps. In addition, regarding α to δ, the diameter dimensions of each component used in real time are described in parentheses.

Interference ratio = (α+β+γ+δ)/(A+B+C+D+E)...(1)

α: tilt angle of the crankshaft based on parallelism (principal - Eccentric part )

β: angle of inclination of the rod based on parallelism (big end - small end )

γ: Angle of inclination of the piston based on verticality (outer diameter - link hole )

δ: Angle of inclination of the frame based on verticality (cylinder barrel - Radial bearings )

A: Frame (radial bearing) - shaft (spindle)

B: crankshaft (eccentric part) - rod (big end part)

C: rod (small end) - piston pin

D: piston pin-piston

E: Piston-Frame (Cylinder)

α is the parallelism between the main shaft 23a of the crankshaft 23 and the eccentric portion 23p. As an example, the diameter (outer diameter) of the main shaft 23a is 18 mm, and the diameter (outer diameter) of the eccentric portion 23p is 15.9 mm. β is the parallelism between the small end portion 25a and the large end portion 25b of the connecting rod 25. As an example, the diameter of the connecting hole 25b1 of the large end portion 25b is set to 15.9 mm, and the diameter of the connecting hole 25a1 of the small end portion 25a is set to 15.9 mm. 9.5mm. γ is the perpendicularity between the outer diameter of the cylindrical portion of the piston 22 and the connecting hole 22a into which the piston pin 29 is inserted. As an example, the outer diameter is set to 25.4mm, and the diameter (outer diameter) of the connecting hole 22a is set to 9.5mm. . δ is the perpendicularity between the axial direction of the cylinder 21 of the frame 24 (the left-right direction in the drawing) and the axial direction of the radial bearing 26 (the up-down direction in the drawing). As an example, the inner diameter of the cylinder 21 is set to 25.4 mm, The diameter (inner diameter) of the radial bearing 26 is set to 18 mm.

As shown in FIG. 3 , A is an inclination angle when the main shaft 23 a is inclined in the radial bearing 26 due to the gap between the main shaft 23 a of the crankshaft 23 and the radial bearing 26 . B is an inclination angle when the eccentric portion 23p is inclined in the large end portion 25b due to a gap between the large end portion 25b of the connecting rod 25 and the eccentric portion 23p of the crankshaft 23 . C is an inclination angle when the piston pin 29 is inclined in the small end portion 25 a due to a gap between the small end portion 25 a of the connecting rod 25 and the piston pin 29 . D is an inclination angle when the piston pin 29 is inclined in the connection hole 22 a due to the gap between the piston pin 29 and the connection hole 22 a of the piston 22 . E is an inclination angle when the piston 22 is inclined in the cylinder 21 due to the gap between the piston 22 and the cylinder 21 of the frame 24 .

Then, when tanA, tanB, tanC, tanD, and tanE are obtained from the inclination angles A, B, C, D, and E shown in FIG. 3 , they can be represented by the following formulas (2) to (6). In addition, since the unit of the middle gap is micron, "×1000" described in the formulas (2) to (6) is to match the unit with the millimeter.

tanA=CLa/(La×1000)...(2)

tanB=CLb/(Lb×1000)...(3)

tanC=CLc/(Lc×1000)...(4)

tanD＝CLd/(Ld×1000)...(5)

tanE＝CLe/(Le×1000)...(6)

In addition, CLa is the distance between the main shaft 23a and the radial bearing 26 at the end (lower end) in the axial direction of the radial bearing 26, and La is the sliding length of the radial bearing 26 through which the main shaft 23a slides. CLb is the distance between the eccentric portion 23p and the large end portion 25b at the axial end (upper end) of the large end portion 25b, and Lb is the sliding length of the large end portion 25b through which the eccentric portion 23p slides. CLc is the distance between the piston pin 29 and the small end 25a at the axial end (lower end) of the small end 25a, and Lc is the sliding length of the small end 25a where the piston pin 29 slides. CLd is the distance between the connecting hole 22a of the piston 22 and the piston pin 29 at the end (upper end) of the piston 22 perpendicular to the axial direction, and Ld is the sliding length of the connecting hole 22a through which the piston pin 29 slides. CLe is the distance between the cylinder 21 and the piston 22 at the axial end of the piston 22 , and Le is the sliding length of the cylinder 21 through which the piston 22 slides.

When A to E are obtained from the above-mentioned formulas (2) to (6), the following formulas (7) to (11) are obtained.

A＝arctan(CLa/(La×1000)...(7)

B＝arctan(CLb/(Lb×1000)...(8)

C＝arctan(CLc/(Lc×1000)...(9)

D＝arctan(CLd/(Ld×1000)...(10)

E＝arctan(CLe/(Le×1000)...(11)

Therefore, when the respective inclination angles A to E are collectively expressed, it becomes the formula (12) shown below.

arctan(each gap/(sliding length×1000))···(12)

In addition, after examining the relationship between the interference ratio and the COP obtained from the above-mentioned formula (1), it was confirmed that the relationship is as follows: As shown in FIG. 4 , the lower the interference ratio, the higher the COP. Therefore, it was confirmed that the COP of the compressor 100 can be improved by obtaining the interference factor from the relationship shown in FIG. 4 .

Therefore, FIG. 5 shows the main shaft length L and the rod pitch when the length of the main shaft length L (refer to FIG. 1 ) is changed by setting numbers other than the inclination angle A of the formula (1) related to the length of the crankshaft 23 as fixed values. The relationship between the ratio (L/P) of P (see Fig. 1) and the interference rate is measured and plotted several times. 1, the main shaft length L in this embodiment refers to the length from the upper end of the main shaft 23a of the crankshaft 23, in other words, from the lower surface 23b1 of the flange portion 23b to the lower end of the radial bearing 26. The rod pitch P refers to the distance connecting the rotation center c1 of the small end portion 25a of the connection rod 25 and the rotation center c2 of the large end portion 25b, as shown in FIG. 1 . Therefore, by shortening the main shaft length L, L/P (main shaft length/rod pitch) becomes small, and by increasing the main shaft length L, L/P becomes large.

As shown in FIG. 5 , it was confirmed that the interference ratio becomes higher as L/P becomes larger. In addition, it was confirmed that L/P has an inflection point around 1.1. That is, it was confirmed that when L/P is 1.1 or less, the interference factor changes along the straight line S1, and when L/P exceeds 1.1, the interference factor changes along the straight line S2. Therefore, when L/P is 1.1 or less, the main axis length L can be shortened while reducing the interference rate. Also, in the case where L/P exceeds 1.1, the interference rate becomes high, and the major axis length L becomes long. Therefore, by setting L/P to 1.1 or less, the crankshaft 23 can be shortened, the compressor 100 can be downsized, the performance of the compressor 100 can be ensured, and malfunction can be prevented (the crankshaft 23 can be prevented from locking). In addition, conventionally, since the main shaft length L is shortened (downsizing the compressor 100 ), the bearing load increases, so it has not been actively adopted. However, it was confirmed that even if the main shaft length L is shortened, by setting L/P to 1.1 or less, the increase in the bearing load accompanying the increase in the bearing load can be tolerated, and the performance of the compressor 100 can be ensured while achieving a small size. change.

In addition, if the method of connecting the piston 22 and the connecting rod 25 is changed from a ball joint to a piston pin method for the purpose of improving the performance of the compressor 100 , high dimensional accuracy is required. However, if the main shaft length L is shortened, the inclination angle of the crankshaft 23 becomes large, so the accuracy of the geometrical tolerance can be eased. In addition, by shortening the main shaft length L, the space of the crankshaft 23 for forming the bore 23c into which the fixed shaft member 23h is inserted is narrowed. By narrowing the space, the area of the cylindrical thin-walled portion is also narrowed compared to a case where the crankshaft is long, so that the rigidity of the crankshaft 23 can be increased to that extent. Since the deflection deformation of the crankshaft 23 can be suppressed, even if the crankshaft 23 is shortened and the compressor 100 is downsized, the performance as the compressor 100 can be ensured.

In addition, in the present embodiment, in the compressor 100, when the axial height of the small end portion 25a is H (refer to FIG. 1 ), the main shaft length L is 3 to 5 times the height H, so that The accuracy of parallelism between the axial direction of the piston pin 29 and the axial direction of the main shaft 23a (central axis O) can be relaxed. Therefore, even if the compressor 100 is downsized by shortening the crankshaft 23 , the performance as the compressor 100 can be ensured.

Fig. 6 is a schematic sectional view of a refrigerator equipped with a compressor according to the present embodiment, (a) is a structure in which the compressor is arranged in the lower part, and (b) is a structure in which the compressor is arranged in the upper part.

As shown in FIG. 6( a ), refrigerator 60A is configured by dividing refrigerator main body 61 into a plurality of storage chambers 62 , 63 , 64 , and 65 . For example, storage room 62 is a refrigerator, storage room 63 is an upper freezer, storage room 64 is a lower freezer, and storage room 65 is a vegetable room. In addition, the positional relationship of each storage chamber 62, 63, 64, 65 is not limited to FIG.6(a). The compressor 100 is arranged in the machine room of the storage room 65 at the lower part of the depth side of the drawer 65 a (the lowermost end on the rear side of the refrigerator main body 61 ). The refrigerant discharged from the compressor 100 passes through a condenser (not shown) and a decompression mechanism (not shown) installed in the refrigerator 60A, absorbs heat in the refrigerator in the cooler 66, and returns to the compressor 100 again. .

However, if a high-profile compressor is used as in the past, the capacity of the machine room needs to be increased, so the capacity of the drawer 65a stored in the storage room 65 becomes small (it becomes a shallow drawer). Therefore, by adopting the refrigerator 60A to which the compressor 100 of this embodiment is applied, the volume of the machine room can be reduced, and the height of the ceiling surface of the machine room can be lowered, so the internal capacity of the storage room 65 on the deep side can be increased.

Moreover, as shown in FIG.6(b), the compressor 100 of refrigerator 60B is arrange|positioned in the machine room of the upper part of the depth side of the storage room 62 (the uppermost end of the back side of the refrigerator main body 61).

However, if a large compressor is used as in the past, the vibration generated by the compressor will be large, so the vibration transmitted to the main body of the refrigerator will also increase. Therefore, by adopting refrigerator 60B to which compressor 100 of this embodiment is applied, vibration can be reduced by the above-mentioned structure, and thus vibration transmitted to refrigerator main body 61 can be suppressed. In addition, by applying the compact compressor 100, the capacity in the storage chamber 62 can also be enlarged.

In addition, this invention is not limited to above-mentioned embodiment, Various changes are possible in the range which does not deviate from the summary of this invention. For example, in this embodiment, the case where the piston 22 and the connecting rod 25 are connected by the piston pin 29 has been described as an example, but not limited to the piston pin 29, a ball joint system may also be used.

Claims (4)

1. a kind of compressor, possesses：Compression unit；Drive the electrodynamic element of above-mentioned compression unit；And the above-mentioned compression list of storage The container of first and above-mentioned electrodynamic element,

Above-mentioned compressor is characterised by,

Above-mentioned compression unit possesses：Cylinder barrel；Moved back and forth in above-mentioned cylinder barrel, so as to the piston of compression refrigerant；Utilize Above-mentioned electrodynamic element carries out the bent axle of eccentric rotary；The eccentric part of above-mentioned bent axle and the bar of above-mentioned piston can rotatably be linked； And the bearing of the above-mentioned bent axle of support,

In the upper end of the main shaft of above-mentioned bent axle, the thickness of radially projecting flange part is below 4mm.

2. a kind of compressor, possesses：Compression unit；Drive the electrodynamic element of above-mentioned compression unit；And the above-mentioned compression list of storage The container of first and above-mentioned electrodynamic element,

Above-mentioned compressor is characterised by,

Above-mentioned compression unit possesses：Cylinder barrel；Moved back and forth in above-mentioned cylinder barrel, so as to the piston of compression refrigerant；Utilize Above-mentioned electrodynamic element carries out the bent axle of eccentric rotary；The eccentric part of above-mentioned bent axle and the bar of above-mentioned piston can rotatably be linked； And the bearing of the above-mentioned bent axle of support,

The offset of above-mentioned bent axle is below 9mm, in the thickness of the radially projecting flange part in the upper end of the main shaft of above-mentioned bent axle For below 4mm.

3. compressor according to claim 1 or 2, it is characterised in that

Above-mentioned compression unit possesses the framework of the above-mentioned bent axle of e axle supporting,

Above-mentioned cylinder barrel is configured with the upside of said frame, above-mentioned electrodynamic element is configured with the downside of said frame,

Said frame is supported in said vesse via elastomeric element,

Above-mentioned elastomeric element is located at the outer circumferential side of above-mentioned cylinder barrel.

4. a kind of refrigerator, it is characterised in that possess compressor according to any one of claims 1 to 3.