JP2010144680A - Compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide technology for improving the reliability of a so-called rear shaft section. <P>SOLUTION: A rotary compressor 1 includes a cylinder body 8, a front bearing 12 and a rear bearing 13 provided such that the cylinder body 8 is placed therebetween, and a crankshaft 5 rotatably supported by the front bearing 12 and the rear bearing 13 and having an eccentric section 14. The center of the rear bearing 13 is shifted in a direction corresponding to a rotation angle θcr=0 to 180[deg.], of the crankshaft 5 relative to the front bearing 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a compressor.

  As this type of technology, Patent Document 1 discloses a rotary compression in which a transmission element part is housed in an upper part of a sealed container and a compression element part is housed in a lower part, and the rotational force of the transmission element part is transmitted to the compression element part by a rotating shaft and driven. The machine is disclosed. The rotating shaft is composed of a long axis of the rotating shaft, an eccentric shaft portion of the rotating shaft, and a short axis of the rotating shaft. And in order to externally fit the rolling piston to the eccentric shaft portion, the outer diameter of the short shaft is set smaller than the outer diameter of the long shaft. In this case, in Patent Document 1, a ring is inserted and fixed on the short shaft so that the reliability of the short shaft does not deteriorate.

JP 2006-132414 A

  The structure of Patent Document 1 has a complicated structure.

  The present invention has been made in view of these points, and its main object is to compare the reliability of a so-called rear shaft portion (corresponding to the short axis in Patent Document 1) with the configuration of Patent Document 1. It is to improve with a simple configuration.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems and the effects thereof will be described.

  The compressor according to the first invention is pivotally supported by a cylinder body, a first bearing and a second bearing provided so as to sandwich the cylinder body, and the first bearing and the second bearing, A crankshaft having an eccentric portion accommodated in the cylinder body, and rotatably supporting the eccentric portion along an inner peripheral surface of the cylinder body; a roller fitted on the eccentric portion; and the cylinder A blade that advances and retreats with respect to a blade accommodating portion that is recessed in the inner peripheral surface of the main body, and divides a cylinder chamber formed in the cylinder main body into a compression chamber and a suction chamber; the cylinder main body; And a prime mover that is provided on the opposite side of the bearing and rotates the crankshaft. The rotation angle of the crankshaft is 0 [deg.] So that the blade housing portion is viewed from the center of the inner peripheral surface of the cylinder body. ], And when the rotation direction of the crankshaft is positive, the second bearing has a rotation angle of the crankshaft of 0 to 180 [deg.] With respect to the first bearing. ] Misaligned in the direction corresponding to According to the above configuration, since the inclination of the crankshaft with respect to the second bearing when the differential pressure load generated by the compression of the refrigerant is maximized, the second bearing, the crankshaft, And the reliability of the crankshaft in the second bearing is improved.

  A compressor according to a second invention is the compressor according to the first invention, wherein the diameter of the rear shaft portion of the crankshaft extending from the eccentric portion in a direction away from the prime mover is set to the eccentric portion toward the prime mover. Is set to a value smaller than the diameter of the front shaft portion of the crankshaft extending from As described above, when the rear shaft portion is set to have a small diameter with respect to the front shaft portion and is in a condition unfavorable for the reliability of the rear shaft portion, the effect of alleviating the above-described one hit becomes more significant. .

Compressor according to the third invention, in the first or compressor according to the second invention, the diameter of the rear shaft portion of the crankshaft extending from said eccentric portion in a direction away from the prime mover and phi _R, the eccentric When the diameter of the part and phi _E, satisfying the following formula (1).

  As described above, when the above-described expression (1) is satisfied and the condition is unfavorable for the reliability of the rear shaft portion, the effect of alleviating the one-side attack becomes more significant.

  According to a fourth aspect of the present invention, in the compressor according to any one of the first to third aspects, carbon dioxide is employed as the refrigerant. Thus, in the compressor for carbon dioxide gas, the differential pressure load generated by the compression of the refrigerant becomes extremely large, which is a disadvantageous condition for the reliability of the crankshaft in the second bearing. Under such conditions, the effect of alleviating the one-sided attack described above becomes more significant.

  As described above, according to the present invention, the following effects can be obtained.

  In the first invention, since the inclination of the crankshaft with respect to the second bearing becomes small when the differential pressure load generated by the compression of the refrigerant becomes maximum, the second bearing and the crankshaft The single hit is alleviated, so that the reliability of the crankshaft in the second bearing is improved.

  Further, in the second invention, when the rear shaft portion is set to have a small diameter with respect to the front shaft portion as described above, the above-mentioned one attrition is reduced when the rear shaft portion becomes unfavorable for reliability. The mitigating effect is more meaningful.

  Moreover, in the third invention, when the above-described expression (1) is satisfied and the reliability of the rear shaft portion is disadvantageous, the effect of relaxing the one-sided attack is more significant. Become.

  In the fourth aspect of the invention, in the compressor for carbon dioxide gas, the differential pressure load generated by the compression of the refrigerant is remarkably increased, which is a disadvantageous condition for the reliability of the crankshaft in the second bearing. It becomes. Under such conditions, the effect of alleviating the one-sided attack described above becomes more significant.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

  First, based on FIG. 1, the structure of the rotary compressor which concerns on 1st embodiment of this invention is outlined. FIG. 1 is an elevational sectional view of a rotary compressor according to a first embodiment of the present invention.

  A rotary compressor 1 shown in FIG. 1 is used as a part of a refrigeration system such as an air conditioner. That is, the air conditioner includes a condenser, an expansion mechanism, an evaporator (not shown), and the rotary compressor 1 described above as main components. The rotary compressor 1 sucks the refrigerant (for example, carbon dioxide gas) in the air conditioner and discharges it at a predetermined pressure.

  As shown in the figure, the rotary compressor 1 includes a sealed container 2, and a motor unit 3 and a compression unit 4 accommodated in the sealed container 2 as main components. The motor unit 3 drives the compression unit 4 via the crankshaft 5, and the compression unit 4 sucks, compresses and discharges low-pressure refrigerant from the accumulator 6 shown schematically. The high-pressure refrigerant in the sealed container 2 is discharged to the outside of the rotary compressor 1 through the discharge pipe 7.

  The compression unit 4 includes a cylinder body 8 having a circular hole 8a, and a front head 9 and a rear head 10 provided so as to sandwich the cylinder body 8 as main components, and the circular hole formed in the cylinder body 8 A cylinder chamber 11 is formed by dividing 8 a by the front head 9 and the rear head 10. In short, a cylinder chamber 11 is formed in the cylinder body 8.

  The crankshaft 5 is pivotally supported by a front bearing 12 (first bearing) formed on the front head 9 and a rear bearing 13 (second bearing) formed on the rear head 10. The eccentric part 14 accommodated in the cylinder body 8 is supported so as to be rotatable along the inner peripheral surface 8 b of the circular hole 8 a of the cylinder body 8. The eccentric portion 14 is formed integrally with the crankshaft 5 so as to turn along the inner peripheral surface 8b as the crankshaft 5 rotates.

  Reference is now made to FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. As shown in this figure, a cylindrical roller 15 is fitted on the eccentric portion 14 of the crankshaft 5, and a direction perpendicular to the axial direction of the crankshaft 5 from the outer peripheral surface 15 a of the roller 15. The blade 16 extends, and the blade 16 is accommodated via a pair of bushes 18 in a blade accommodating portion 17 that is recessed in the inner peripheral surface 8 b of the cylinder body 8. The blade 16 divides the cylinder chamber 11 into a compression chamber 27a and a suction chamber 27b (see also FIG. 4). A supply port 19 for receiving the supply of refrigerant from the accumulator 6 is formed in the vicinity of the blade housing portion 17, and a supply pipe 20 (FIG. 1) connected to the accumulator 6 is formed in the supply port 19. The supply port 19 has a supply port 21 on the inner peripheral surface 8 b of the circular hole 8 a of the cylinder body 8.

  Next, please refer to FIG. 1 and FIG. 3 together. 3 is a cross-sectional view taken along line 3-3 in FIG. As shown in FIGS. 1 and 3, the front head 9 is formed in a plate shape, closes the circular hole 8a of the cylinder body 8, and has a plate portion 9b having a through hole 9a through which the crankshaft 5 passes. And the above-described front bearing 12 (first bearing) formed to extend from the edge of the through hole 9a of the plate portion 9b toward the motor portion 3 in a cylindrical shape. The plate portion 9b of the front head 9 is provided with a discharge hole 23 for discharging the refrigerant compressed in the cylinder chamber 11, and for appropriately controlling the discharge of the refrigerant through the discharge hole 23. A discharge control mechanism 24 is attached. Further, the front head 9 is covered with a muffler 25 for reducing noise caused by the pulsation of the refrigerant. The muffler 25 has a muffler discharge hole 26 for discharging the refrigerant discharged from the discharge hole 23 to the outside of the muffler 25. Reference is now made to FIG. FIG. 4 is a diagram similar to FIG. 2 and is an explanatory diagram of the operation of the rotary compressor. As schematically indicated by a two-dot chain line in the figure, the discharge hole 23 is located on the opposite side of the supply port 21 and the blade 16. In other words, the front head 9 is rotationally positioned with respect to the cylinder body 8 so that the supply port 21 and the discharge hole 23 sandwich the blade 16 in a plan view of the cylinder body 8 as shown in FIG. . With this configuration, as shown in this figure, when the roller 15 turns while maintaining a contact state with the inner peripheral surface 8 b of the circular hole 8 a of the cylinder body 8, the blade 16 moves forward and backward with respect to the blade housing portion 17. At the same time, the refrigerant supplied into the cylinder body 8 is compressed. In addition, the thick line arrow in this figure shows the turning direction (rotation direction of the crankshaft 5) of the roller 15.

  Hereinafter, for convenience of explanation, a portion of the crankshaft 5 extending from the eccentric portion 14 toward the motor 22 (prime mover) constituting the motor portion 3 in FIG. 1 is referred to as a front shaft portion 5f. On the other hand, a portion of the crankshaft 5 extending from the eccentric portion 14 in a direction away from the motor 22 is referred to as a rear shaft portion 5r.

  The shape of the rear head 10 described above is similar to the main shape of the front head 9. That is, as shown in FIG. 1, the rear head 10 is formed in a plate shape, closes the circular hole 8a of the cylinder body 8, and has a plate portion 10b having a through hole 10a through which the crankshaft 5 passes, and this plate. The above-described rear bearing 13 (second bearing) is formed to extend from the edge of the through hole 10a of the portion 10b in a cylindrical shape in a direction away from the motor portion 3. Lubricating oil (not shown) is filled between the rear head 10 and the sealed container 2.

  Next, a rotation angle θcr of the crankshaft 5 is defined based on FIG. FIG. 5 is a diagram similar to FIG. 2 and is an explanatory diagram used for defining the rotation angle of the crankshaft. The rotation angle θcr of the crankshaft 5 is specified by the relative positional relationship between the front shaft portion 5f (or the rear shaft portion 5r) of the crankshaft 5 and the eccentric portion 14, and the cylinder body 8 Of the crankshaft 5 with a rotational angle θcr of 0 [deg. ]. Specifically, 0 [deg.] Of the rotation angle θcr of the crankshaft 5 is viewed from the center of the inner peripheral surface 8 b of the cylinder body 8 toward the center of the blade housing portion 17 in the circumferential direction. ]. In other words, the starting point of the rotation angle θcr of the crankshaft 5 is the state shown in FIG. 5, that is, the state where the blade 16 is most accommodated in the blade accommodating portion 17, and the blade 16 enters the blade accommodating portion 17 most. Set to state. Then, the rotation angle θcr of the crankshaft 5 is positive in the rotation direction of the crankshaft 5 (clockwise in the figure).

  With the above configuration, in the rotary compressor 1 according to the present embodiment, the rear bearing 13 has the rotation angle θcr = 0 to 180 [deg. ] Misaligned in the direction corresponding to In other words, the rear bearing 13 is positioned with respect to the front bearing 12 so that the rear bearing 13 is misaligned with respect to the front bearing 12 as described above.

The diameter phi _R of the rear shaft portion 5r is set to a value smaller than the diameter phi _F of the front shaft portion 5f (see also FIG. 7). Further, to satisfy the diameter phi _R of the rear shaft portion 5r, the diameter phi _E of the eccentric portion 14, the following equation (1).

  Next, the operation of the rotary compressor 1 according to this embodiment will be outlined.

  In the state of FIG. 5 in which the rotation angle θcr of the crankshaft 5 is zero, low-pressure carbon dioxide gas is supplied into the cylinder chamber 11 from the supply port 19 through the supply port 21. In this state, when the eccentric portion 14 (crankshaft 5) turns in the direction indicated by the thick arrow in the drawing and the eccentric portion 14 passes the supply port 21 in the circumferential direction, the pressure of the carbon dioxide gas starts to increase. When the pressure of the carbon dioxide gas exceeds the set pressure set using the discharge control mechanism 24 shown in FIG. 1, the discharge control mechanism 24 opens, and the high-pressure carbon dioxide gas passes through the discharge hole 23. It is discharged into the muffler 25. The high-pressure carbon dioxide gas discharged into the muffler 25 is silenced in the muffler 25 and then discharged from the compression unit 4 through the muffler discharge hole 26. The high-pressure carbon dioxide gas compressed in the compression unit 4 passes through the motor 22 constituting the motor unit 3, and is eventually discharged to the outside of the rotary compressor 1 through the discharge pipe 7 provided in the sealed container 2. .

  Next, the technical significance of the misalignment between the front bearing 12 and the rear bearing 13 will be described in detail with reference to FIG. FIG. 6 is a partial view exaggerating the characteristic portion of the rotary compressor.

FIG. 6A shows a conventional example, and FIG. 6B shows an example. In each figure, the maximum differential pressure load is imaged with a white arrow. As shown in FIG. 6A, in the conventional example, as a rule, the front bearing 12 and the rear bearing 13 are positioned with respect to the cylinder body 8 so as to satisfy a predetermined coaxiality. Accordingly, when the crank shaft 5 receives the maximum difference pressure load of the bends arcuately to schematically so by the two-dot chain line in the figure, as shown the tilt by codes theta _A, rear axis relative to the rear bearing 13 The part 5r is inclined, the rear bearing 13 and the rear shaft part 5r are one-sided, and the reliability of the rear shaft part 5r is deteriorated due to uneven wear resulting from this one-sided attack. Strictly speaking, “the rear shaft portion 5r is inclined with respect to the rear bearing 13” means that the axis of the rear shaft portion 5r is relative to the bearing center line specified by the inner peripheral surface of the rear bearing 13. "Inclined" means that it should be interpreted in this manner as needed.

On the other hand, as shown in FIG. 6B, in the embodiment, the front bearing 12 is misaligned with respect to the rear bearing 13 in the load direction of the maximum differential pressure load. Then, the presence of this intentional misalignment, in the absence of differential pressure, as shown the tilt by codes theta _B, rear shaft portion 5r is slightly inclined with respect to the rear bearing 13. When the crankshaft 5 receives the maximum difference pressure load of the bends, to tilt it is reduced or disappears as shown in the above code theta _B. In other words, the inclination θ _A and the inclination θ _B are in a canceling relationship. Accordingly, the inclination of the rear shaft portion 5r with respect to the rear bearing 13 when the differential pressure load generated by the compression of the refrigerant is maximized is reduced, and the one-sided attack between the rear bearing 13 and the rear shaft portion 5r is alleviated. The reliability of the rear shaft portion 5r in the rear bearing 13 is improved.

  Next, the above-mentioned misalignment amount of the center misalignment will be described in detail with reference to FIG.

  First, please refer to FIG. FIG. 7 is an explanatory diagram for calculating a suitable amount of misalignment. Here, how much the rear bearing 13 is misaligned with respect to the front bearing 12, the inclination of the rear shaft portion 5r with respect to the rear bearing 13 disappears when the differential pressure load caused by the compression of the refrigerant becomes maximum. Or the derivation method will be described. In the following description, the description will be made on the assumption that the center misalignment direction of the center misalignment coincides with the load direction of the maximum differential pressure load. First, mathematical formulas used for this derivation are listed as follows.

Then, explaining from the conclusion, if the variable Δt [mm] is set so that the variable θ _A of the formula (3) and the variable θ _B of the formula (5) are matched as much as possible, the refrigerant When the differential pressure load generated by the compression of the rear bearing 13 becomes maximum, the one-side hit between the rear bearing 13 and the rear shaft portion 5r is alleviated, and the reliability of the rear shaft portion 5r in the rear bearing 13 is improved.

  Now, each variable used in the above equations (2) to (5) will be described with reference to FIG.

The variables b [mm] and c [mm] in the above equations (2) and (3) are as follows. That is, when the crankshaft 5 receives a differential pressure load and bends into an arcuate shape, the crankshaft 5 is simply supported by the front bearing 12 and the rear bearing 13 at three locations. For convenience of explanation, this simple support portion is illustrated as a support point A, a support point B, and a support point C in order from the motor unit side. The variable b [mm] is a distance specified along the axial direction of the crankshaft 5 and is a distance between the support point B and the axial center of the eccentric portion 14. Similarly, the variable c [mm] is a distance specified along the axial direction of the crankshaft 5 and is a distance between the support point C and the axial center of the eccentric portion 14. The variable Rc [kgf] in the equation (2) is a part of the reaction force of the maximum differential pressure load generated by the compression of the refrigerant, and is at the support point C described above. The variable W [kgf] in the above equations (2) and (3) is a load that acts on the center of the eccentric portion 14 in the axial direction due to the maximum differential pressure load generated by the compression of the refrigerant. The variable E [kgf / mm ² ] in the above equation (3) is the Young's modulus of the crankshaft 5. The variable θ _{A in} the above equation (3) is the inclination angle of the rear shaft portion 5r with respect to the rear bearing 13 when the differential pressure load generated by the compression of the refrigerant is maximized (in addition to the sign θ _{A in} FIG. 6). reference.). The average of the above formula (4) variable D [mm] of a diameter phi _F of the front shaft portion 5f [mm] and the diameter of the rear shaft portion 5r φ _R [mm], the variable d [mm] is the crankshaft 5 It is an internal diameter of a cylindrical hole (not shown) formed inside. The variable θ _B [deg. ] Is an inclination angle of the rear shaft portion 5r with respect to the rear bearing 13 when the differential pressure load is zero. The variable Lf [mm] in the above formula (5) is the so-called F / H length, that is, Lf is the thickness of the front bearing inside the front head 9. The bearing of the front head has a function of supporting a reaction force for compressing the refrigerant in the compression chamber and a radial force (consisting of a suction force and an inertial force) from the motor. Lf represents the bearing length that supports the compression reaction force. For example, when the bearing is divided vertically in the axial direction and the bearing that mainly supports the compression reaction force is viewed as the lower side (compression chamber side), Lf is the lower bearing length. If the bearing structure does not have a split section, the length of one connected bearing is LF. The variable Hc [mm] in the above equation (5) is the thickness of the cylinder body 8 in the axial direction of the crankshaft 5. The variable Hr [mm] in the above equation (5) is the thickness of the rear head 10 including the rear bearing 13 in the axial direction of the crankshaft 5. The variable Δt [mm] in the above equation (5) is the amount of misalignment between the axis of the front bearing 12 and the axis of the rear bearing 13.

Hereinafter, a specific calculation example of the amount of misalignment of the above misalignment will be introduced.
D [mm] = 16
D [mm] = 9
B [mm] = 15
C [mm] = 15
・ W [kgf] = 250
E [kgf / mm ² ] = 10000
・ Lf [mm] = 40
・ Hr [mm] = 15
・ Hc [mm] = 16
Under the above conditions, when Δt [mm] = 11 × 10 ⁻³ , the variable θ _A in the above equation (3) and the variable θ _{B in the} above equation (5) substantially coincide.

  Reference is now made to FIG. FIG. 8 is an explanatory diagram for calculating a preferred misalignment direction. In the graph shown in FIG. 8, the horizontal axis indicates the rotation angle θcr [deg. The vertical axis represents the differential pressure load w [kgf] generated by the compression of the refrigerant. Here, if the rear bearing 13 is decentered in any direction with respect to the front bearing 12, the inclination of the rear shaft portion 5r with respect to the rear bearing 13 when the differential pressure load caused by the compression of the refrigerant becomes maximum disappears. The method of derivation will be described. First, mathematical formulas used for this derivation are shown as follows. The differential pressure load w [kgf] was obtained by numerically calculating the pressure change in the cylinder chamber 11 using a general-purpose application, assuming that the compression process with volume change is performed under isentropic change. It was obtained by multiplying the pressure change and the area where the pressure acts.

  The variable θcr1 [deg. ] Is the load direction of the maximum differential pressure load. Similarly, the variable θcr2 [deg. ] Is the rotation angle θcr of the crankshaft 5 at the time of the maximum differential pressure load.

  Here, a specific calculation example is given. That is, for example, when HFC (R410A) is used as the refrigerant and the so-called operating pressure (High Pressure / Low Pressure) is 5/1 [MPa], in a certain type of rotary compressor, as shown in FIG. deg. ] Was 230. When this value is substituted into the above equation (6), the load direction θcr1 [deg. ] Is 115. Therefore, the rear bearing 13 has a rotational angle θcr = 115 [deg. It is most preferable to shift the direction in the direction corresponding to In addition, it is preferable to give a slight width | variety from the viewpoint of productivity, for example, ± 60 [deg. It is conceivable to have a degree of tolerance. In this case, the rear bearing 13 is at a rotational angle θcr = 55 to 175 [deg. ], The front bearing 12 and the rear bearing 13 are relatively positioned so as to be misaligned in the direction corresponding to More preferably, the rear bearing 13 has a rotation angle θcr of the crankshaft 5 of 90 to 180 [deg. ] The front bearing 12 and the rear bearing 13 may be relatively positioned so that they are misaligned in the direction corresponding to The maximum load point was confirmed in the compression ratio (Hp / Lp) area where the compressor could be operated (desktop calculation). The maximum compressor load was developed at a crankshaft rotation angle of 180 to 360 degrees. Therefore, 90-180 ° is suitable for the misalignment angle (from Equation 6).

  In other words, the rotation angle θcr2 of the crankshaft 5 at the time of the maximum differential pressure load shown in FIG. 8 varies depending on the type of refrigerant employed. That is, for example, when carbon dioxide gas having a specific heat ratio larger than that of the above-mentioned Freon gas is employed, the rotation angle θcr2 of the crankshaft 5 at the time of maximum differential pressure load is slightly lower than in the case of FIG. Since the rotation angle θcr2 of the crankshaft 5 at the time of the maximum differential pressure load shown in FIG. 8 varies depending on the type of refrigerant employed in this way, the inventors of the present invention have conducted various calculations, and as a result, I came to such a conclusion. That is, considering all types of refrigerants that can be employed, the rear bearing 13 has a rotational angle θcr = 0 to 180 [deg. It is preferable to shift the center in the direction corresponding to <Reason why the misalignment angle = 0 to 180 ° is effective> The misalignment angle 90 to 180 ° is a case where attention is paid to the maximum load point and R410A. As in 0051, when there is a characteristic that the operating compression ratio in the refrigeration circuit becomes low due to the low specific heat ratio such as carbon dioxide refrigerant or the usage environment of the refrigeration circuit, not only the maximum load point but also the high crankshaft angle before 180 deg. Paying attention also to the load (compression ratio 1.7 etc.), it is necessary to improve bearing strength. In such a case, both the misalignment setting angle of 90 ° or less and 90 to 180 ° are effective. Therefore, a misalignment angle of 0 to 180 ° is suitable.

(Summary)
(Claim 1)
As described above, in the above embodiment, the rotary compressor 1 is configured as follows. That is, the rotary compressor 1 includes a cylinder body 8, a front bearing 12 (first bearing) and a rear bearing 13 (second bearing) provided so as to sandwich the cylinder body 8, and the front bearing 12. A crankshaft 5 that is pivotally supported by a rear bearing 13 and has an eccentric portion 14 that is accommodated in the cylinder body 8, and supports the eccentric portion 14 so as to be rotatable along the inner peripheral surface 8 b of the cylinder body 8. A cylinder chamber formed in the cylinder body 8 by moving forward and backward with respect to the roller 15 fitted on the eccentric portion 14 and the blade housing portion 17 recessed in the inner peripheral surface 8b of the cylinder body 8. 11 is divided into a compression chamber 27a and a suction chamber 27b, and is provided on the opposite side of the blade 16, the cylinder body 8 and the front bearing 12, and rotates the crankshaft 5. It includes a prime mover), a. The rear bearing 13 has a rotational angle θcr = 0 to 180 [deg. ] Misaligned in the direction corresponding to According to the above configuration, since the inclination of the crankshaft 5 with respect to the rear bearing 13 when the differential pressure load generated by the compression of the refrigerant is maximized, the piece of the rear bearing 13 and the crankshaft 5 is reduced. Atari is alleviated, so that the reliability of the crankshaft 5 in the rear bearing 13 is improved.

In addition, from the viewpoint of reducing mechanical loss, it is preferable that the diameter φ _E of the eccentric portion 14 is small. However, the eccentric portion 14 needs to be eccentric with respect to the crankshaft 5, and further, the roller 15 needs to be externally fitted to the eccentric portion 14 as in the above embodiment. Therefore, in order to reduce the mechanical loss, it is necessary to reduce the diameter phi _R of the rear shaft portion 5r. However, reducing the diameter phi _R of the rear shaft portion 5r, the reliability of the rear shaft portion 5r is reduced. That is, the mechanical loss and the reliability of the rear shaft portion 5r are in a technical trade-off relationship. Therefore, the technique for mitigating the above-described one attack will be useful as one means for solving such a trade-off.

  In the above-described embodiment, the cylinder chamber 11 formed in the cylinder body 8 is moved forward and backward with respect to the blade housing portion 17 recessed in the inner peripheral surface 8b of the cylinder body 8, and the compression chamber 27a and the suction chamber 27b. The blade 16 is divided into a roller 15 as shown in FIG. However, instead of this, the blade 16 may be formed separately from the roller 15. In such a case, it is considered that the blade 16 is pressed against the outer peripheral surface 15a of the roller 15 by appropriate biasing means such as a compression coil spring.

(Claim 2)
The rotary compressor 1 is further configured as follows. That is, the diameter phi _R of the rear shaft portion 5r is set to a value smaller than the diameter phi _F of the front shaft portion 5f. As described above, when the rear shaft portion 5r is set to have a small diameter with respect to the front shaft portion 5f and is in a condition unfavorable for the reliability of the rear shaft portion 5r, the effect of alleviating the above-described one hit is further improved. It makes sense.

(Claim 3)
The rotary compressor 1 is further configured as follows. That is, the diameter of the rear shaft portion 5r and phi _R, when the diameter of the eccentric portion 14 and phi _E, satisfying the following formula (1). As described above, when the above-described expression (1) is satisfied and the condition is unfavorable for the reliability of the rear shaft portion 5r, the effect of alleviating the one-sided attack becomes more significant.

Hereinafter, it will be described that satisfying the above expression (1) results in an unfavorable condition for the reliability of the rear shaft portion 5r. See Figures 9-11. FIG. 9 is a first explanatory diagram for explaining the influence of φ _E / φ _R. FIG. 10 is a second explanatory diagram for explaining the influence of φ _E / φ _R. FIG. 11 is a third explanatory diagram for explaining the influence of φ _E / φ _R.

  That is, the damage pattern of the rear bearing 13 of the rotary compressor 1 is, for example, as follows.

During high differential pressure operation, the shaft bends due to the operational differential pressure, causing the bearing and the shaft to tilt. When tilt occurs, the oil film between the shaft and the bearing becomes thin, and metal contact is likely to occur. Ease of metal contact is determined by the load generated by the amount of tilt and the operating differential pressure. When metal contact occurs, the coefficient of friction increases, and the amount of heat generated at the bearing increases. The amount of heat generation increases as the rotational speed increases. There is a PV value (surface pressure × speed) as a guide for knowing the magnitude of the calorific value. The relationship between the PV value and the cooling by the oil around the bearing portion determines whether or not the bearing is damaged. If the PV value is large and the amount of cooling by oil is small, the probability of bearing damage increases. That is, (1) a region where the load value is high, and (2) a region where the PV value is high. The technology of the present application improves bearing reliability by reducing the inclination of the bearing and the shaft. With the parameters shown below (see also FIG. 9), the load and PV value of the rear bearing of the rotary compressor were calculated. The results are summarized as shown in FIG. 10 (load) and FIG. 11 (PV value). 10 and 11, it can be seen that the load and the PV value increase in the region where φ _E / φ _R is 2 or less. That is, in the region where φ _E / φ _R is 2 or less, it is a condition that is disadvantageous to the reliability of the rear shaft portion 5r.

-Diameter d [mm] of the rear shaft portion 5r = 8.0 to 28.0
-Thickness t [mm] of roller 15 = 2.0 to 8.0
Step β [mm] = 0.0 to 0.4
-Thickness Hc [mm] of cylinder body 8 = 6.0 to 16.0
-Effective bearing length L [mm] of the rear bearing 13 = 6.0 to 25.0
・ Operating differential pressure ΔP [MPa] = 3.0
・ Operation speed N [Hz] = 90.0

(Claim 4)
The rotary compressor 1 employs carbon dioxide as the refrigerant. As described above, in the rotary compressor 1 for carbon dioxide gas, the differential pressure load generated by the compression of the refrigerant becomes extremely large, which is a disadvantageous condition for the reliability of the crankshaft 5 in the rear bearing 13. Under such conditions, the effect of alleviating the one-sided attack described above becomes more significant.

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 12 is a view similar to FIG. 1, and is an elevational sectional view of the rotary compressor according to the second embodiment of the present invention.

  Here, it demonstrates centering on the point which is different from said 1st embodiment, and omits the description about the overlapping point. Members common to the rotary compressor 1 according to the first embodiment and the rotary compressor 1 according to the second embodiment are denoted by the same reference numerals.

  First, in the first embodiment, only one cylinder body 8 is provided. However, in this embodiment, two cylinder bodies 8 are arranged in parallel in the axial direction of the crankshaft 5. A middle plate 28 is interposed between the two cylinder bodies 8 arranged side by side. The eccentric portion 14 is accommodated in each of the two cylinder bodies 8 arranged side by side. That is, the crankshaft 5 includes two eccentric portions 14.

  In the first embodiment, the muffler 25 is attached only to the front head 9, but in this embodiment, it is further attached to the rear head 10.

  In the first embodiment, the front shaft portion 5f is in contact with the front bearing 12, and the rear shaft portion 5r is in contact with the rear bearing 13, but this point is the same in the second embodiment. The middle shaft portion 29 of the crankshaft 5 between the two eccentric portions 14 arranged side by side is in a loosely inserted relationship with respect to the middle plate 28.

  With the above configuration, the rotation angle θcr of the crankshaft 5 is newly defined by focusing only on the rear eccentric portion 31 as the eccentric portion 14 on the side closer to the rear shaft portion 5r of the two eccentric portions 14 provided in parallel. Is done.

  Also in the present embodiment, as in the above-described embodiment, the rear bearing 13 has a rotational angle θcr = 0 to 180 [deg. ] Misaligned in the direction corresponding to

  Hereinafter, a suitable amount of misalignment of the above-described misalignment in the present embodiment will be described in detail with reference to FIG.

  In order to calculate a suitable amount of misalignment of the above-described misalignment in this embodiment, among the above formulas (2) to (5), formula (5) may be replaced with the following formula (7).

  The variable b [mm] and the variable c [mm] in the above formulas (2) and (3) are as follows. That is, when the crankshaft 5 receives a differential pressure load and bends into an arcuate shape, the crankshaft 5 is simply supported by the front bearing 12 and the rear bearing 13 at three locations. For convenience of explanation, this simple support portion is illustrated as a support point A, a support point B, and a support point C in this order from the motor unit side as in FIG. The variable b [mm] and the variable c [mm] are specified based on the support points A, B, and C as in the first embodiment. The variable Hm [mm] in the above equation (7) is the thickness of the middle plate 28.

Then, if the variable Δt [mm] is set so that the variable θ _A of the above formula (3) and the variable θ _B of the above formula (5) match as much as possible, the differential pressure generated by the compression of the refrigerant One-side hit between the rear bearing 13 and the rear shaft portion 5r when the load becomes maximum is alleviated, and the reliability of the rear shaft portion 5r in the rear bearing 13 is improved.

  Note that the center misalignment direction of the center misalignment in the present embodiment may be obtained as described based on FIG. 8 while focusing only on the rear eccentric portion 31.

  If the present invention is utilized, since the inclination of the crankshaft with respect to the second bearing when the differential pressure load generated by the compression of the refrigerant becomes maximum, the second bearing, the crankshaft, And the reliability of the crankshaft in the second bearing is improved.

Elevation view sectional drawing of the rotary compressor which concerns on 1st embodiment of this invention. 2-2 sectional view of FIG. Sectional view taken along line 3-3 in FIG. It is a figure similar to FIG. 2, Comprising: Operation | movement explanatory drawing of a rotary compressor It is a figure similar to FIG. 2, Comprising: Explanatory drawing provided for the definition of the rotation angle of a crankshaft Partial drawing exaggerating the features of a rotary compressor Explanatory diagram for calculating a suitable amount of misalignment Explanatory diagram for calculating the preferred misalignment direction First explanatory diagram for explaining the influence of φ _E / φ _R Second explanatory diagram for explaining the influence of φ _E / φ _R Third explanatory diagram for explaining the influence of φ _E / φ _R FIG. 2 is a view similar to FIG. 1, and is an elevational sectional view of a rotary compressor according to a second embodiment of the present invention. It is a figure similar to FIG. 7, Comprising: Explanatory drawing for calculating the suitable amount of misalignment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotary compressor 3 Motor part 4 Compression part 5 Crankshaft 8 Cylinder body

Claims (4)

A cylinder body,
A first bearing and a second bearing provided so as to sandwich the cylinder body;
Having an eccentric portion that is pivotally supported by the first bearing and the second bearing and is accommodated in the cylinder body, and supports the eccentric portion so as to be rotatable along the inner peripheral surface of the cylinder body; A crankshaft,
A roller externally fitted to the eccentric part;
A blade that advances and retreats with respect to a blade housing portion that is recessed in the inner peripheral surface of the cylinder body, and divides a cylinder chamber formed in the cylinder body into a compression chamber and a suction chamber;
A prime mover that is provided on the opposite side of the cylinder body and the first bearing and rotates the crankshaft;
With
The rotation angle of the crankshaft is 0 [deg.] So that the blade housing portion is viewed from the center of the inner peripheral surface of the cylinder body. ], And when the rotation direction of the crankshaft is positive, the second bearing has a rotation angle of the crankshaft of 0 to 180 [deg.] With respect to the first bearing. ] Misaligned in the direction corresponding to
Compressor. The compressor according to claim 1,
The diameter of the rear shaft portion of the crankshaft extending from the eccentric portion in a direction away from the prime mover is set to a value smaller than the diameter of the front shaft portion of the crankshaft extending from the eccentric portion toward the prime mover.
Compressor. The compressor according to claim 1 or 2,
When the diameter of the rear shaft part of the crankshaft extending from the eccentric part in the direction away from the prime mover is φ _R and the diameter of the eccentric part is φ _E , the following formula (1) is satisfied:
Compressor.

The compressor according to any one of claims 1 to 3, wherein carbon dioxide gas is used as the refrigerant.

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