CN101725504A

CN101725504A - Refrigerant compressor

Info

Publication number: CN101725504A
Application number: CN200910205421A
Authority: CN
Inventors: 中西博志
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 2008-10-23
Filing date: 2009-10-23
Publication date: 2010-06-09
Anticipated expiration: 2029-10-23
Also published as: CN101725504B; JP2010101232A

Abstract

A refrigerant compressor is provided. In which less than 5% of the power crankshaft matrix is made of ferrite, other part of the matrix made of flaky graphite cast iron made of pearlite containing Cr, Mo or Ni; or, the 50% of the crankshaft matrix by area rate is made of pearlite, other part of the matrix is made of nodular cast iron composed of ferrite; and, the main bearing for supporting the crankshaft is made of flaky graphite cast iron (grey cast iron) without alloy; the graphite on the upper part of the main bearing is eutectiform grapbite; and the pearlite exists in the matrix by percentage between 30% and 95%.

Description

Coolant compressor

Technical field

The present invention relates to a kind of in enterprise and home-use refrigerating and air conditioning employed coolant compressor.

Background technique

As existing coolant compressor, the bent axle that transmits the power of compressor uses the material that adds alloy in grey cast iron (flake graphite cast iron).In recent years, at the high efficiency specification that requires of compressor, adopt and the flake graphite nodular cast iron koji axle that specific rigidity is higher mutually more and more.The tissue crystals of nodular cast iron goes out spheroidal graphite, and the pearlite of matrix (matrix) and ferrite disperse.Ferrite is than pearlite, soft and anti-burning, and anti-sliding is poor, has as much as possible less with the restriction of the ferrite ratio in the matrix.

On the other hand, the main bearing of supporting crankshaft uses calcined materials or grey cast iron in the past always.If on main bearing, use grey cast iron, then in casting process, sharply cooled off easily near the top of main bearing.Therefore, made original long flake graphite refining eutectic of extending, having matrix is matrix easily with the ferrite, in the situation of generation problem aspect the wearability of bent axle.

Fig. 6 is the photomicrograph of metal structure on main bearing top of the coolant compressor of expression TOHKEMY 2000-110719 communique.As can be seen, graphite is eutectic (the D shape of ASTM (American Society for Testing and Materials) type), and matrix is ferrite (white portion).Ferrite matrix is softer, so wearability is poor.

Summary of the invention

As mentioned above, most matrixes of the material of bent axle use the grey cast iron as pearlitic adding alloy.And, in bent axle, use under the situation of nodular cast iron, select fully to have guaranteed the pearlitic material in the matrix.But, though the main bearing of the rotation of supporting crankshaft uses grey cast iron, on the top of main bearing, in existing problems aspect the wearability of bent axle.Therefore, must provide stable Mechanical Reliability by the metal structure on control main bearing top.

Therefore, coolant compressor of the present invention, its matrix that bent axle of power is provided are the ferrites below 5%, and remaining matrix is the flake graphite cast iron that contains Cr, Mo or Ni that is made of pearlite.Perhaps the matrix of bent axle is the pearlite of area ratio more than 50%, and remaining matrix is the nodular cast iron that is made of ferrite.The employed material of the main bearing of supporting crankshaft is the flake graphite cast iron (grey cast iron) that does not comprise alloy, and the graphite on main bearing top is eutectic graphite, and has the pearlite below 95% more than 30% in the matrix.

Common graphite is the A shape graphite of ASTM classification, and the general whole surface of matrix is a pearlitic structrure.When the casting main bearing, particularly the top of main bearing is sharply cooled off, and graphite becomes tiny eutectic graphite (the D shape graphite of ASTM classification) easily.In the case, matrix becomes ferrite easily.And, because bent axle is subjected to by the vibration stress of the motor of shrink fit (shrinkage fit), therefore, and the top of main bearing between become the strictest sliding condition, wearability slightly descends.Therefore,, guarantee the hard pearlite matrix more than at least 30% in ferrite matrix by in the matrix at this position, can guarantee and bent axle between wearability.

Description of drawings

Fig. 1 is mechanism's longitudinal section partly of the coolant compressor of embodiments of the present invention.

Fig. 2 is the cross-sectional view of major component of the compressing mechanism of this coolant compressor of expression.

Fig. 3 is the schematic representation of the metal structure observation place of the top of main bearing of this coolant compressor of expression and bottom.

Fig. 4 is the photomicrograph of metal structure on the main bearing top of this coolant compressor of expression.

Fig. 5 is the photomicrograph of metal structure of the main bearing bottom of this coolant compressor of expression.

Fig. 6 is the photomicrograph of metal structure on top of the main bearing of the existing coolant compressor of expression.

Embodiment

Below, with reference to accompanying drawing, embodiments of the present invention are described.

As traditional coolant compressor, rotary compressor is one of its representative, therefore, describes as the situation of coolant compressor using rotary compressor.Fig. 1 is the longitudinal section of mechanism part of the coolant compressor of embodiments of the present invention, and Fig. 2 is the cross-sectional view of major component of the compressing mechanism of this coolant compressor of expression.

In Fig. 1, coolant compressor disposes motor part 2, compression mechanical part 3 etc. in closed container 1.Motor part 2 is made of rotor 2a and stator 2b, and bent axle 8 is fixed on the rotor 2a by method such as being pressed into, and this bent axle 8 is by main bearing 9 and supplementary bearing 10 free rotary ground supportings.Compressor section 3 comprises eccentric part, blade 21, main bearing 9 and the supplementary bearing 10 of cylinder 20, roller 7, bent axle 8.Herein, cylinder 20 has the cylinder groove 23 of inlet hole 5 and radial direction.The inner peripheral surface of the outer circumferential face one edge cylinder 20 of roller 7 slides, and one side is eccentric to rotate.The eccentric part of running shaft 8 is inserted into the inner peripheral surface of roller 7 in the mode that is free to slide.Blade 21 is incorporated in the cylinder groove 23 in the mode that freely reciprocatingly slides, and utilizes the pushing force and the back pressure (head pressure) of spring 24, and tip portion is by to roller 7 pushing, and the inner space of cylinder 20 is divided into suction chamber 25 and pressing chamber 26.Two end faces of main bearing 9 and supplementary bearing 10 sealing cylinders 20.

Below, the action of the rotary compressor of said structure is described.Rotor 2a by from the outside to motor part 2 energising rotate, axle 8 is driven in rotation.If axle 8 rotations, on one side then with the mode that is free to slide be installed in roller 7 on the eccentric part will be on one side with the cylinder inner peripheral surface on sliding contact carry out planetary motion (planetary movement: the anticlockwise rotation among Fig. 2).Its result, the refrigerant gas of HFC (hydrogen fluorine carbide) etc. is inhaled into the suction chamber 25 from suction pipe 4 and by inlet hole 5.Simultaneously, in pressing chamber 26, the refrigerant gas that pressure is enhanced is from discharging groove 22 and being discharged in the closed container 1 by tap hole 6.

In order in Fig. 1, to observe easily, the position of tap hole 6 is drawn in the position away from inlet hole, still, in fact as shown in Figure 2, it clips blade 21, be configured in inlet hole 5 near.

At this moment, the blade 21 of separating suction chamber 25 and pressing chamber 26 passes through at blade back applied pressure by the outer circumferential face pushing to roller 7 because of spring 24.The tip portion of blade 21 is slided on the outer circumferential face of roller 7, and the side face of blade 21 is slided on the internal face of cylinder groove 23.Under the steady running state, use the refrigerator oil 11 that is stored in closed container 1 bottom to come lubricating blade 21 and roller 7 and cylinder groove 23.But, when starting, in slide part, do not have enough refrigerator oils, and use a spot of refrigerator oil 11 that is included in the refrigerant gas that is inhaled into.Herein, a spot of refrigerator oil 11 together is discharged from from compressor with refrigerant gas, after being circulated throughout freeze cycle, returns compressor from suction pipe 4 once more.

Bent axle 8 general low-alloy cast iron or the nodular cast irons of using.The lubricant oil of the sliding condition when as mentioned above, closed rotary compressor starts can not fully be supplied with.Being to rotatablely move between bent axle 8 and main bearing 9 and the supplementary bearing 10 particularly, therefore being difficult to form oil film, is strict more sliding condition.And, owing to consider that for environmental protection the HFC refrigeration agent that adopts itself lacks lubricity recent years, therefore, use the especially strictness of sliding condition of the rotary compressor of HFC refrigeration agent.

Fig. 3 is the schematic representation of top 31 and the metal structure observation place of bottom 32 of main bearing of the coolant compressor of expression embodiments of the present invention, and Fig. 4 is the photomicrograph of metal structure on the main bearing top of this coolant compressor of expression.

As shown in Figure 3, the less thick on the top of main bearing 9.Graphite is eutectic (the D shape of ASTM classification), and still, matrix is the tissue of separating out pearlite (grey) in ferrite (white).As can be seen, in the example of the photomicrograph of Fig. 4, matrix be pearlite more than 80%, graphite is eutectic, still, what difference is the normal structure of matrix and main bearing bottom (A shape graphite+pearlite) almost do not have.

The top of the tissue of the main bearing 9 of embodiments of the present invention is sharply cooled off, and is eutectic graphite, still, in order to ensure the either pearlite occurred of matrix, realizes matrix strengthening by the adjustment of inoculation (inoculation) and the interpolation of pearlite promotion element.Therefore, bent axle 8 certainly uses the grey cast iron that contains alloy, even comprise under the situation of ferritic nodular cast iron koji axle in using matrix, also can guarantee mechanical sliding.

Fig. 5 is the photomicrograph of lower metal tissue of main bearing of the coolant compressor of expression embodiments of the present invention.As can be seen, it is the tissue of original grey cast iron (graphite form is the A shape shape of ASTM classification), and the most of matrix of matrix is a pearlite.Because pearlite is harder than ferrite, therefore, its wearability is good.

As mentioned above, the matrix that the bent axle 8 of power is provided is the ferrite below 5%, and remaining matrix is the flake graphite cast iron that comprises Cr, Mo or Ni that is made of pearlite.Perhaps, the matrix of bent axle 8 is that the pearlite area ratio is, remaining matrix is the nodular cast iron that is made of ferrite more than 50%.And the main bearing 9 employed materials of supporting crankshaft 8 are the flake graphite cast irons (grey cast iron) that do not contain alloy, and the graphite on the top of main bearing 9 is eutectic graphites, and, in matrix, there is the pearlite more than 30%, below 95%.

Common graphite is the A shape graphite of ASTM classification, and the roughly whole surface of matrix is a pearlitic structrure.When casting main bearing 9, particularly the top of main bearing 9 is sharply cooled off, and graphite becomes tiny eutectic graphite (the D shape graphite of ASTM classification) easily.In the case, matrix becomes ferrite easily.And, because bent axle 8 is subjected to by the vibration stress of the motor after the shrink fit, therefore, and the top of main bearing 9 between become the strictest sliding condition, wearability slightly descends.Therefore, in the matrix at this position, guarantee the hard pearlite more than at least 30% in ferrite matrix, thus, just can guarantee and bent axle 8 between wearability.

Because of being subjected to the vibration of the motor after the shrink fit on the bent axle 8, its wall thickness is designed to reduced size, and therefore, the material of the grey cast iron on the top of main bearing 9 is also same with the processed finished products of main bearing 9, and the wall thickness on top is cast into less size.Generally speaking, this position is positioned at the position away from the flow gate that enters the mouth as metallic solution when casting, and, sharply to be cooled off easily owing to wall thickness, graphite and insufficient growth are difficult to become flake graphite.Therefore, separate out crystallization as eutectic graphite, the pearlite of matrix is not enough yet, becomes ferrite matrix, therefore, is easy to generate problem aspect wearability.Certainly, aspect casting, by in metallic solution, using inoculation,, certain limit is arranged though can realize to a certain degree the homogenizing of tissue.In the present invention,, guarantee the either pearlite occurred of the matrix of this part, therefore, can guarantee sufficient sliding with bent axle 8 by optimizing inoculation and adding pearlite promotion element etc.

Employed refrigeration agent is HCFC (HCFC) in the coolant compressor, and refrigerator oil is a mineral oil.Perhaps, employed refrigeration agent is HFC in the coolant compressor, and refrigerator oil is ester or ether oil.

Its result is even the refrigeration agent stricter HFC refrigeration agent condition that is HCFC or lubricating condition also can be guaranteed sufficient mechanical slip reliability.

Claims

1. coolant compressor is characterized in that:

The matrix that the bent axle of power is provided is the ferrite below 5%, remaining matrix is the flake graphite cast iron that contains Cr, Mo or Ni that is made of pearlite, perhaps the pearlite area ratio is more than 50%, remaining matrix is the nodular cast iron that is made of ferrite, the employed material of main bearing that supports described bent axle is the flake graphite cast iron (grey cast iron) that does not comprise alloy, the graphite on described main bearing top is eutectic graphite, and has the pearlite below 95% more than 30% in matrix.

2. coolant compressor as claimed in claim 1 is characterized in that:

Refrigeration agent is HCFC, and refrigerator oil is a mineral oil, and perhaps described refrigeration agent is HFC, and described refrigerator oil is ester or ether oil.