JP2016089625A - Rotary compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary compressor reducing mechanical loss and attaining quietness.SOLUTION: A rotary compressor includes: a crank shaft 2 having an eccentric part 21; electric motor parts 11, 12 rotating the crank shaft 2; and a thrust bearing part having a thrust surface 21as of the eccentric part 21 and a bearing surface 7a of closing member 7 sliding on the thrust surface 21as. For a clearance between the thrust surface 21as and the bearing surface 7a, in a view from a rotational direction M of the crank shaft 2, a front side end part P in the rotational direction M has a larger clearance than a rear side end part R in the rotational direction M.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a rotary compressor that compresses refrigerant gas such as a refrigeration air conditioning system.

  As a rotary compressor which compresses refrigerant gas, such as a refrigerating and air-conditioning system, patent documents 1 are indicated, for example. In a rotary compressor, an electric motor part and a compression mechanism part are housed in a sealed container of the compressor, and a crankshaft having an eccentric part for the purpose of transmitting the rotational torque of the electric motor part to the compression mechanism part is provided. Is provided. The motor part is a rotor having a stator in which an electric wire made of an electric conductor such as copper or aluminum is wound around an iron core, and a magnet such as a neodymium magnet or a ferrite magnet in a slot provided in the iron core surface or in the iron core. And is composed of. Further, the crankshaft is engaged with the rotor by press-fitting, shrink fitting, cold fitting, etc., and the compression mechanism portion generates the rotational torque in the rotor circumferential direction and the magnetic attraction force in the rotor shaft direction generated by the electric motor portion. To communicate.

  The compression mechanism portion includes a cylinder, a roller disposed in the cylinder and driven to rotate by an eccentric portion of the crankshaft, and a vane extending to the outer periphery of the roller and entering and exiting a storage portion provided in the cylinder according to the eccentric motion of the roller. And a spring for pressing the vane against the roller, and a closing member having a bearing portion that closes the upper and lower end surfaces of the cylinder and holds the crankshaft. The bearing portion is composed of a radial bearing for the purpose of holding the crankshaft in the circumferential direction and the radial direction of the crankshaft, and a thrust bearing portion for the purpose of holding the crankshaft in the axial direction.

  Refrigerating machine oil for the purpose of lubrication of the compression mechanism and bearing is stored in the lower part of the hermetic container of the compressor, and the compressor mechanism and the sliding part of the compression mechanism and crankshaft are moved by the operation of the compressor. Supplied.

  After the refrigerant gas (working fluid) is compressed in the compression mechanism, it is discharged into the hermetic container of the compressor, passes through the side surfaces of the stator and the rotor that serve as the motor part, and the discharge provided above the hermetic container. It is discharged from the pipe to the refrigeration cycle.

  Here, the thrust bearing portion holds the own weight of the crankshaft and the rotor and the axial magnetic attractive force generated by the electric motor portion. It is common to bear much.

  The load that the thrust bearing part bears includes the downward weight of the crankshaft and the stator and the magnetic attractive force generated by the motor part, and the side surface of the rotor where the refrigerant gas is engaged with the motor part, particularly the crankshaft. This is the combined force of the upward force generated when passing through.

  The downward force varies depending on the configuration of the electric motor unit. For example, when the height of the rotor core is increased and a ferromagnetic material such as a neodymium magnet is used, the downward force is increased due to the self-criticality of the motor unit and the large magnetic attractive force. Further, when the height of the rotor core is lowered and a magnetic material such as a ferrite magnet is used, the downward force is reduced due to the small weight of the motor unit and the small magnetic attraction force of the motor unit.

  On the other hand, the upward force acts as a force for the refrigerant gas to push up the lower surface of the rotor. For this reason, for example, when the rotational speed of the motor unit is increased and the flow rate of the refrigerant gas is increased, or when the outer diameter of the rotor is increased and the pressure receiving surface of the refrigerant gas is increased, the upward force is increased.

JP 2008-298037 A

  In recent years, application of low GWP (Global warming potential) refrigerants (for example, R32 and natural refrigerants) and higher efficiency of compressors have been demanded from the viewpoint of reducing environmental impact. For example, to increase the efficiency of the compressor, reduction of mechanical loss in the sliding portion of the compression mechanism portion is one solution, and in particular, improvement in lubricity of the sliding portion is required.

  The first problem to be solved by the present invention is to reduce the mechanical loss in the thrust bearing portion that holds the axial load of the crankshaft. Reduction of the bearing area is effective for reducing the mechanical loss in the thrust bearing part, but on the other hand, if the bearing area is reduced too much, the surface pressure may become excessive, and the mechanical loss may increase due to reduced lubrication. Compatibility with ensuring reliability when changing refrigerants is an issue.

  The second problem is noise reduction by suppressing the axial movement of the crankshaft. The axial load of the crankshaft is held by the thrust bearings provided on the upper and lower closing members of the cylinder as described above, but the downward load generated by the weight of the crankshaft and the rotor of the axial load. Since this force is always generated regardless of the operation of the compressor, it is generally held in the thrust bearing portion of the lower closing member, and the crankshaft is always thrust bearing of the lower closing member. It is desirable to be in contact with the part.

  However, in recent years, high efficiency of compressors and improvement in heating capacity of air conditioning equipment are desired. With the increase of the rotor outer diameter in the motor section and the increase in the number of rotations of the compressor, the axial load of the crankshaft is increased. Among them, the upward force is large, so that the movement of the crankshaft in the axial direction occurs, and contact with the lower thrust bearing portion is not guaranteed, so that the crankshaft and the upper and lower closing members There was a concern about the occurrence of a beating sound.

  Then, this invention makes it a subject to provide the rotary compressor which reduced the mechanical loss and was silenced.

  In order to solve such problems, the present invention provides a crankshaft having an eccentric portion, an electric motor portion that rotates the crankshaft, a thrust surface of the eccentric portion, and a bearing of a closing member that slides on the thrust surface. A thrust bearing portion configured to include a surface, and a gap between the thrust surface and the bearing surface is viewed in a rotation direction of the crankshaft, and a front end portion in the rotation direction is a rear end in the rotation direction. The rotary compressor is characterized in that the gap is larger than a side end portion.

  According to the present invention, it is possible to provide a rotary compressor with reduced mechanical loss and reduced noise.

It is a longitudinal cross-sectional view of the rotary compressor which concerns on this embodiment. It is a partial expanded sectional view of the thrust bearing part vicinity in the rotary compressor which concerns on this embodiment. It is a perspective view of a crankshaft. It is an AA arrow directional view of FIG. It is an AA arrow directional view of FIG. 2 showing the rotation direction and thrust surface shape of a crankshaft. It is the expanded view developed by the B line | wire of FIG. 5, (a) is this embodiment, (b) is a modification of this embodiment, (c) shows a reference example.

  Hereinafter, modes for carrying out the present invention (hereinafter referred to as “embodiments”) will be described in detail with reference to the drawings as appropriate. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

≪Rotary compressor≫
A rotary compressor according to this embodiment will be described with reference to FIG. FIG. 1 is a longitudinal sectional view of a rotary compressor according to this embodiment.

  As shown in FIG. 1, the rotary compressor according to the present embodiment includes an airtight container 1 serving as a case, an electric motor unit including a stator 11 and a rotor 12, and an eccentricity that transmits the rotation of the rotor 12. A crankshaft 2 having a portion 21 and a compression mechanism portion that performs compression work by the rotational power of the crankshaft 2 are provided. The electric motor part, the crankshaft 2 and the compression mechanism part are arranged in the sealed container 1.

  The motor part is a rotating machine having a stator 11 in which an electric wire made of an electric conductor such as copper or aluminum is wound around an iron core, and a magnet such as a neodymium magnet or a ferrite magnet in a slot part provided on the surface of the iron core or inside the iron core. And a child 12. The stator 11 is fixed to the inside of the hermetic container 1, and the rotor 12 is fixed to the crankshaft 2 by press-fitting, shrink fitting, cold fitting or the like.

  The compression mechanism section is provided in the cylinder 3 according to the eccentric movement of the cylinder 3, the roller 4 disposed in the cylinder 3 and driven to rotate by the eccentric section 21 of the crankshaft 2, and extending to the outer periphery of the roller 4. The upper bearer which has the vane 5 (refer FIG. 4) which goes in and out of the accommodated storage part 3b (refer FIG. 4), the upper bear closed end surface 6a which closes the upper end surface of the cylinder 3, and the radial bearing part 6b which hold | maintains the crankshaft 2. 6, and a lower bear 7 having a lower bearing closing end surface 7 a that closes the lower end surface of the cylinder 3 and a radial bearing portion 7 b that holds the crankshaft 2.

  The crankshaft 2 is held in the circumferential direction and the radial direction of the rotation axis of the crankshaft 2 by the radial bearing portion 6 b of the upper bear 6 and the radial bearing portion 7 b of the lower bear 7. In addition, the crankshaft 2 is formed by a thrust bearing portion including a lower end surface (a lower thrust surface 21 as described later with reference to FIG. 2) of the eccentric portion 21 of the crankshaft 2 and a lower bear closed end surface 7 a of the lower bear 7. Is held in the axial direction.

  The refrigerant compression operation of the rotary compressor according to the present embodiment will be described along the flow of the refrigerant gas (working fluid). The refrigerant gas that has flowed from the suction pipe 13 connected to the refrigeration cycle (not shown) flows into the cylinder 3 from the suction port 8 provided in the cylinder 3. The refrigerant gas flowing into the cylinder 3 is formed by the cylinder inner wall surface 3a, the roller outer wall surface 4a, the side surface of the vane 5 (see FIG. 4), the upper bear closed end surface 6a, and the lower bear closed end surface 7a. The pressure is increased in the compression chamber 9 and discharged from the discharge port (not shown) into the sealed container 1. The discharge port (not shown) may be provided on the partition wall surface between the upper bear 6 and the sealed container 1 or may be provided on the partition surface between the lower bear 7 and the sealed container 1.

  The refrigerant gas discharged into the hermetic container 1 passes through the gap between the stator 11 and the rotor 12 and the gap between the stator 11 and the hermetic container 1, and the discharge pipe 14 provided on the upper part of the hermetic container 1. To the refrigeration cycle (not shown).

  In the lower part of the hermetic container 1, a refrigerating machine oil 10 for lubricating the compression mechanism is stored. The refrigerating machine oil 10 is sucked up from an oil supply passage 2 a provided in the axial direction of the crankshaft 2. An oil supply passage 2b for supplying oil from the oil supply passage 2a to the radial bearing portion 7b of the lower bear 7, and an oil supply passage 2c for supplying oil from the oil supply passage 2a to the eccentric portion 21 of the crankshaft 2, the inner wall surface 4b of the roller, and a thrust bearing portion described later. And the refrigerating machine oil 10 is supplied to each sliding part by the oil supply path 2d which supplies oil to the radial bearing part 6b of the upper bear 6 from the oil supply path 2a. Incidentally, the refrigerating machine oil 10 is drawn up from the oil supply passage 2a by the principle of a centrifugal pump by extending the oil supply passages 2b to 2d in the radial direction of the crankshaft 2 rotating.

  Next, the structure of the crankshaft 2 and the structure of the thrust bearing portion formed at the sliding portion between the crankshaft 2 and the lower bear 7 will be further described with reference to FIGS. FIG. 2 is a partially enlarged sectional view in the vicinity of a thrust bearing portion in the rotary compressor according to the present embodiment. FIG. 3 is a perspective view of the crankshaft.

  As shown in FIGS. 2 and 3, the crankshaft 2 includes the eccentric portion 21, the lower shaft 22 held by the radial bearing portion 7 b of the lower bear 7, and the upper shaft held by the radial bearing portion 6 b of the upper bear 6. And a shaft 23.

  The lower shaft 22 is provided with a recessed groove portion 22a dug down over the entire circumference in the circumferential direction (in other words, the shaft diameter is smaller than others), and the oil supply passage 2b communicates with the recessed groove portion 22a. Yes. With such a configuration, the refrigerating machine oil 10 supplied from the oil supply passage 2b via the oil supply passage 2a is supplied to the concave groove portion 22a formed over the entire circumference, and the lower shaft 22 and the lower shaft 22 of the crankshaft 2 are lowered from the concave groove portion 22a. Since it is supplied to the sliding portion of the bear 7 with the radial bearing portion 7b, the radial bearing portion 7b can be suitably lubricated.

  Further, the refrigerating machine oil 10 supplied from the oil supply passage 2b is also supplied from the concave groove portion 22a to the radial bearing portion 7b of the lower bear 7. Thereby, when lubricating a thrust bearing portion described later (sliding portion between the lower thrust surface 21as of the crankshaft 2 and the lower bear closed end surface 7a of the lower bear 7), the groove portion 22a dug down over the entire circumference in the circumferential direction. Since the refrigerating machine oil 10 is supplied via the thrust bearing, the thrust bearing portion can be suitably lubricated.

  Similarly, the upper shaft 23 is provided with a recessed groove portion 23a dug down over the entire circumference in the circumferential direction (in other words, the shaft diameter is smaller than others), so that the oil supply passage 2d communicates with the recessed groove portion 23a. It has become. With such a configuration, the refrigerating machine oil 10 supplied from the oil supply passage 2d via the oil supply passage 2a is supplied to the concave groove portion 23a formed over the entire circumference, and the upper shaft 23 and the upper shaft 23 of the crankshaft 2 are Since it is supplied to the sliding part of the bear 6 with the radial bearing part 6b, the radial bearing part 6b can be suitably lubricated.

  Moreover, the eccentric part 21 has the lower thrust surface member 21a which has lower thrust surface 21as which is a lower end surface, and the upper thrust surface member 21b which has upper thrust surface 21bs which is an upper end surface.

  Since the crankshaft 2 has the eccentric portion 21, the crankshaft 2 is rotated slightly tilted during operation. In order to avoid point contact between the lower thrust surface 21as and the lower bare closed end surface 7a due to the inclination of the crankshaft 2, the lower thrust surface 21as is formed to be inclined in the radial direction. That is, the lower thrust surface 21as becomes higher as the distance from the axial center of the crankshaft 2 increases in the radial direction, in other words, away from the lower bear closed end surface 7a, and in other words, the lower thrust surface 21as. The lower bear closed end face 7a is slightly inclined so as to have a large gap, and the center side is a convex surface. Similarly, the upper thrust surface 21bs becomes lower as it goes away from the center of the crankshaft 2 in the radial direction, in other words, away from the upper bare closed end surface 6a, in other words, the upper thrust surface 21bs. And the upper bare closed end surface 6a are slightly inclined so that the gap is large, and the center side is a convex surface.

  Here, as shown in FIGS. 1 and 2, the rotary compressor according to the present embodiment is a vertical rotary compressor in which the crankshaft 2 is in the vertical direction (see FIG. 1), and the crankshaft 2 and the rotor. The crankshaft 2 is urged downward by its own weight.

  For this reason, the thrust bearing portion of the crankshaft 2 is constituted by a lower thrust surface 21 as which is a lower end surface of the eccentric portion 21 of the crankshaft 2 and a lower bear closed end surface 7 a which is an upper end surface of the lower bear 7. .

  Next, oil supply to the thrust bearing portion (the lower thrust surface 21a and the lower bear closed end surface 7a) will be described with reference to FIG. 4A to 4D are views taken along line AA in FIG. 4 (a) to 4 (d), hatching is shown so that the lower thrust surface 21as that becomes a sliding portion with the lower bare closed end surface 7a (see FIG. 2) becomes clear. Yes. In addition, C0 indicates the rotation center of the crankshaft 2, C1 indicates the eccentric portion center of the eccentric portion 21, and the eccentric portion center C1 rotates clockwise on the paper surface of FIG. It is assumed that the crankshaft 2 rotates. Further, the state in which the vane 5 is housed in the housing portion 3b of the cylinder 3 by the eccentric motion of the eccentric portion 21 of the crankshaft 2 (in other words, the state where the eccentric portion center C1 is closest to the housing portion 3b). (A) is the state where the rotation angle is 0 °, (b) is the state where the rotation angle is 90 °, (c) is the state where the rotation angle is 180 °, and (d) is the rotation angle. Indicates a state of 270 °.

  The oil supply to the thrust bearing portion is performed by the refrigerating machine oil 10 that has reached the lower bear closed end surface 7a through the oil supply passages 2a and 2c of the crankshaft 2 shown in FIGS. 1 and 2 due to the rotational movement of the lower thrust face 21as. It is made by entering between the closed end face 7a and the lower thrust face 21as.

  Here, as shown in FIG. 4, the shape of the lower thrust surface 21 as (lower thrust surface member 21 a) of the crankshaft 2 is a circle centered on the rotation center C <b> 0 and an eccentric portion as viewed in the axial direction of the crankshaft 2. It is formed in a region where a circle centering on the center C1 (a circle along the outer shape of the eccentric portion 21) overlaps. That is, the shape of the lower thrust surface 21as of the crankshaft 2 includes a circular arc centered on the rotation center C0 (an upper arc in FIG. 4A) and a circular arc centered on the eccentric center C1 ( 4 (a), the arc on the lower side of the paper surface).

  When the rotation angle of the crankshaft 2 shifts from 0 ° (see FIG. 4A) to 90 ° (see FIG. 4B) due to such a shape of the lower thrust surface 21as, FIG. When the refrigerating machine oil at the position of the refrigerating machine oil 10a shown in FIG. 2 enters between the lower bear closed end face 7a and the lower thrust face 21as, the oil is supplied to the thrust bearing portion.

  Similarly, when the rotation angle of the crankshaft 2 shifts from 90 ° (see FIG. 4B) to 180 ° (see FIG. 4C), the position of the refrigerating machine oil 10b shown in FIG. When the refrigerating machine oil enters between the lower bear closed end surface 7a and the lower thrust surface 21as, the oil is supplied to the thrust bearing portion. In addition, when the rotation angle of the crankshaft 2 shifts from 180 ° (see FIG. 4C) to 270 ° (see FIG. 4D), the refrigeration at the position of the refrigerating machine oil 10c shown in FIG. The machine oil enters between the lower bear closed end surface 7a and the lower thrust surface 21as, so that oil is supplied to the thrust bearing portion. Further, when the rotation angle of the crankshaft 2 shifts from 270 ° (see FIG. 4 (d)) to 360 ° (see FIG. 4 (a)), the refrigeration at the position of the refrigerating machine oil 10d shown in FIG. 4 (d) is performed. The machine oil enters between the lower bear closed end surface 7a and the lower thrust surface 21as, so that oil is supplied to the thrust bearing portion.

  As described above, the oil supply start point to the sliding portion between the lower thrust surface 21as and the lower bearer closed end surface 7a provided on the crankshaft 2 is determined by the rotation direction of the crankshaft 2 and is always at the same position. In other words, among the circular arcs (circular arcs on the lower side in FIG. 4A) centered on the eccentric center C1 of the lower thrust surface 21as, the crankshaft 2 is rotated forward (FIG. 4A). At the right side of the paper).

  5 is a view taken along the line AA of FIG. 2 showing the rotation direction of the crankshaft and the shape of the thrust surface.

  Here, the arrow M shown in FIG. 5 indicates the rotation direction of the crankshaft 2. A broken line B shown in FIG. 5 is a line (arc) on a circle around the rotation center C0 of the crankshaft 2. Of the circular arc (the arc on the lower side of the paper in FIG. 5) centered on the broken line B and the eccentric center C1 of the lower thrust surface 21as, the arc on the front side in the rotational direction M of the crankshaft 2 (the arc on the right side of the paper in FIG. 5). ) Is defined as a refueling start point P. Of the circular arc (circular arc on the lower side in FIG. 5) centered on the broken line B and the eccentric center C1 of the lower thrust surface 21as, the rear side in the rotational direction M of the crankshaft 2 (the arc on the left side in FIG. 5). ) Is the end point R. A point between the oil supply start point P and the end point R on the broken line B on the arc is defined as an intermediate point Q.

  The refrigerating machine oil 10a (see FIG. 4A) is formed between the lower bear closed end surface 7a and the lower thrust surface 21as from the fuel supply start point P by the crankshaft 2 rotating in the rotation direction M around the rotation center C0. When the crankshaft 2 further rotates, the refrigerating machine oil 10a supplied from the oiling start point P is guided to the intermediate point Q, and further, the crankshaft 2 rotates to the end point R, that is, The thrust bearing is lubricated evenly.

  Here, the total amount of oil supplied between the lower bear closed end surface 7a and the lower thrust surface 21as is determined by the amount of oil introduced at the oil supply start point, but the refrigeration near the oil supply start point is determined. The machine oil 10a to 10d enters between the two planes (between the lower bare closed end surface 7a and the lower thrust surface 21as) and the side surface (lower thrust surface) of the lower thrust surface member 21a (see FIG. 3) of the eccentric portion 21. And the surface that is scraped by the surface substantially perpendicular to 21as.

  6A and 6B are development views developed along line B in FIG. 5, where FIG. 6A shows this embodiment, FIG. 6B shows a modification of this embodiment, and FIG. 6C shows a reference example. That is, FIG. 6 is a diagram showing the relationship of the distance between the lower thrust surface 21as and the lower bear closed end surface 7a in the circumferential direction (rotational direction) of the crankshaft 2 along the B line. In FIG. 6, points on the lower bare closed end surface 7a facing the oil supply start point P, the intermediate point Q, and the end point R on the lower thrust surface 21as are point P0, point Q0, and point R0, respectively.

<Reference example>
First, the shape of the lower thrust surface 21as of the crankshaft 2 in the rotary compressor according to the reference example will be described with reference to FIG. In the rotary compressor according to the reference example, as shown in FIG. 6C, the lower thrust surface 21as and the lower bear closed end surface 7a are arranged in parallel (substantially parallel).

  As described above, since the oil supply between the lower bear closed end surface 7a and the lower thrust surface 21as is started from between the oil supply start points P and P0, between the intermediate points Q and Q0 and the end points R and R0. The amount of oil supply up to the point is determined by the amount of oil supplied between the two planes (between the lower bear closed end surface 7a and the lower thrust surface 21as) between the oil supply start points P and P0.

  Also in the rotary compressor according to the reference example, the amount of oil supply between the two planes arranged in parallel (substantially parallel) is set within a range in which a sufficient amount can be secured in terms of reliability.

  On the other hand, in the demand for higher efficiency of the rotary compressor, the area of the lower bare closed end face 7a (for the purpose of reducing mechanical loss for the purpose of reducing mechanical loss and ensuring reliability by improving lubricity) ( In order to reduce the bearing area, an improvement in oil supply between the two planes is required in order to withstand an increase in surface pressure due to a reduction in the area of the lower bear closing end surface 7a.

  Further, in order to improve the refrigerating capacity of the refrigerating cycle, the rotary compressor is required to operate at high speed, and the upward load that pushes up the lower end surface of the rotor 12 out of the axial load of the crankshaft 2 accompanying the increase in the refrigerant circulation amount. In order to increase the surface tension of the refrigerating machine oil 10 that has entered between the two planes in order to counteract the force, an improvement in oil supply between the two planes is required.

  In recent years, switching from the current high GWP refrigerant (for example, R410A) to a low GWP refrigerant (for example, R32 or natural refrigerant) has been demanded from the viewpoint of reducing environmental burden. By the way, compared with R410A refrigerant | coolant, R32 refrigerant | coolant has the characteristics that the suction density of the refrigerant | coolant of a compressor is small and the discharge temperature of the refrigerant | coolant of a compressor becomes high. For this reason, the temperature of the refrigerating machine oil 10 also rises, and the viscosity decreases due to the temperature rise. It is also conceivable to use a low-viscosity refrigerating machine oil 10 for the purpose of reducing the mechanical loss of the rotary compressor. Thus, since the refrigerating machine oil 10 hold | maintained between the said 2 planes will also escape easily when the viscosity of the refrigerating machine oil 10 becomes low, the improvement of the oil supply property between the said 2 planes is calculated | required.

<This embodiment>
Next, the shape of the lower thrust surface 21as of the crankshaft 2 in the rotary compressor according to this embodiment will be described with reference to FIG. In the rotary compressor according to the present embodiment, the lower thrust surface 21as and the lower bear closed end surface 7a are arranged non-parallel. In other words, the distance (gap) between the lower bear closed end surface 7a and the lower thrust surface 21as is not the same but different.

That is, in the rotary compressor according to this embodiment, the lower thrust surface 21as of the crankshaft 2 with respect to the lower bear closed end surface 7a is
(Distance between points P and P0)> (Distance between points Q and Q0)> (Distance between points R and R0) (1)
It is characterized in that an inclination is provided at an angle α. That is, in the circumferential direction (rotational direction) of the crankshaft 2 (see line B in FIG. 5), the distance (gap) between the lower bear closed end surface 7a and the lower thrust surface 21as is the rotational direction M of the crankshaft 2. The front side (the right side in FIG. 6A) is longer (larger) than the rear side in the rotational direction M of the crankshaft 2 (the left side in FIG. 6A).

  According to the rotary compressor according to the present embodiment having such a configuration, the amount of the refrigerating machine oil 10 scraped by the side surface of the lower thrust surface member 21a of the eccentric portion 21 (the surface substantially perpendicular to the lower thrust surface 21as) is reduced. The amount of oil supply that decreases and enters between the two planes (between the lower bear closed end surface 7a and the lower thrust surface 21as) can be increased. That is, the oil supply to the thrust bearing portion that bears the axial load of the crankshaft 2 is improved. Thus, the increase in the amount of oil supply between the two planes (improvement of oil supply) makes it possible to achieve both reduction in mechanical loss and ensuring reliability.

  In addition, when the rotary compressor is operating at high speed, the flow rate of the refrigerant gas flowing from the discharge port (not shown) of the compression mechanism section to the discharge pipe 14 increases, and the crankshaft 2 tends to rise. Since the oil supply between the two planes is sufficiently performed, the gap between the two planes is filled with the refrigerating machine oil 10 from the oil supply start point P to the end point R, and the surface tension of the refrigerating machine oil 10 is sufficiently increased. It can be demonstrated. As described above, the crankshaft 2 is closely attached to the lower bear closed end surface 7a (lower bear 7) due to the surface tension of the refrigerating machine oil 10 that has entered the gap between the two planes, and the crankshaft 2 can be prevented from being lifted. it can. Thereby, generation | occurrence | production of the tapping sound at the time of the crankshaft 2 moving to an axial direction and colliding with the upper bear 6 or the lower bear 7 can be prevented, and the silence of a rotary compressor can be ensured. In other words, a rotary compressor capable of high speed operation can be provided.

  Moreover, even if the refrigerant | coolant whose discharge temperature becomes high like R32 refrigerant | coolant is used, the reliability of a thrust bearing part can be ensured by increasing the amount of oil supply. Moreover, even if low-viscosity refrigerating machine oil 10 is used. By increasing the amount of oil supply, the reliability of the thrust bearing portion can be ensured.

The angle α of the lower thrust surface 21as shown in FIG.
0 ° <α ≦ 0.2 ° (2)
Is desirable. The maximum rotational speed of the rotary compressor (the rotational speed of the crankshaft 2) is desirably 10,000 rpm or less, and the viscosity of the refrigerating machine oil 10 is desirably 10 to 100 cSt (at 40 ° C.).

  By making the angle α larger than 0 ° (0 ° <α), the amount of oil that enters between the two planes (between the lower bear closed end surface 7a and the lower thrust surface 21as) is larger than that in the reference example. can do. On the other hand, as the angle α is larger, the amount of oil that enters between the two planes (between the lower bear closed end surface 7a and the lower thrust surface 21as) can be increased. Since 10 is foamed, the rotational resistance of the crankshaft 2 increases, which is not preferable. For this reason, it is desirable that the angle α be 0.2 ° or less (α ≦ 0.2 °).

  In order to avoid point contact between the lower thrust surface 21as and the lower bear closed end surface 7a, the lower thrust surface 21as is formed to be inclined in the radial direction as described above. For this reason, although the refrigerating machine oil 10 taken in from the refueling start point P may escape to the outside, the refrigerating machine oil 10 can be spread to the intermediate point Q and the end point R by increasing the refueling amount.

<Modification of this embodiment>
Next, the shape of the lower thrust surface 21as of the crankshaft 2 in the rotary compressor according to the modification of the present embodiment will be described with reference to FIG.

  As shown in FIG. 6A, the lower thrust surface 21as of the rotary compressor according to this embodiment is composed of one inclined surface having an angle α. On the other hand, the lower thrust surface 21as of the rotary compressor according to the modification of the present embodiment includes an inclined surface (oil supply start point P to intermediate point Q) and a lower bear closed end surface as shown in FIG. 7a and parallel planes (substantially parallel) (intermediate point Q to end point R). Other configurations are the same, and the description is omitted.

That is, in the rotary compressor according to the modification of the present embodiment, the lower thrust surface 21as of the crankshaft 2 with respect to the lower bear closed end surface 7a is
(Distance between points P and P0)> (Distance between points Q and Q0) = (Distance between points R and R0) (3)
In this case, an inclined surface and a parallel surface are provided.

  According to the rotary compressor according to the modification of the present embodiment having such a configuration, the lower thrust surface member 21a of the eccentric portion 21 is the same as the rotary compressor according to the present embodiment (see FIG. 6A). The amount of the refrigerating machine oil 10 scraped by the side surface (surface substantially perpendicular to the lower thrust surface 21as) decreases, and the amount of oil that enters between the two planes (between the lower bare closed end surface 7a and the lower thrust surface 21as) is reduced. Can be increased.

  Further, a part of the lower thrust surface 21as of the rotary compressor according to the modification of the present embodiment is a parallel surface (intermediate point Q to end point R) that is parallel (substantially parallel) to the lower bare closed end surface 7a. Accordingly, an increase in surface pressure between the two planes, which slightly increases due to an inclined surface (oil supply start point P to intermediate point Q) that inclines the lower thrust surface 21as in the circumferential direction, is suppressed, and mechanical loss is reduced. The surface tension due to the machine oil 10 can be increased.

  In addition, since the lower thrust surface 21as of the rotary compressor according to the present embodiment is inclined to the end point R, it is compared with the lower thrust surface 21as of the rotary compressor according to the modification of the present embodiment. This is preferable in that the amount of oil supply is preferably increased to the end point R.

<Modification>
The rotary compressor according to this embodiment is not limited to the configuration of the above embodiment, and various modifications can be made without departing from the spirit of the invention.

  The rotary compressor according to the present embodiment has been described as a vertical rotary compressor. However, the rotary compressor is not limited to this. For example, the rotary compressor may be a horizontal rotary compressor in which the crankshaft 2 is in the horizontal direction. . In the case of a horizontal rotary compressor, the crankshaft 2 is urged (pressed) in one direction by an urging means such as an axial magnetic attractive force generated by an electric motor section or a spring. For this reason, in the thrust bearing portion which is a sliding portion between the end surface of the biased direction side bear (closing member) and the end surface of the eccentric portion 21 of the crankshaft 2, the thrust bearing in the rotary compressor according to the present embodiment. A structure similar to the structure of the part may be applied.

  Although the rotary compressor according to the modification of the present embodiment has been described as the lower thrust surface 21as shifting from the inclined surface to the parallel surface at the intermediate point Q at the intermediate position from the oil supply start point P to the end point R. However, it is not limited to this. The position at which the lower thrust surface 21as moves from the inclined surface to the parallel surface may be closer to the fuel supply start point P or closer to the end point R.

  Further, the inclined surface when the lower thrust surface 21as is viewed in the circumferential direction is described as being inclined linearly in FIGS. 6A and 6B, but is not limited thereto, and is not limited to a curved line. It may be inclined in a shape. Moreover, you may be comprised with the some inclined surface from which an inclination angle differs.

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Crankshaft 2a Oil supply path (1st oil supply means, 2nd oil supply means)
2b Oil supply path (first oil supply means)
2c Oil supply path (second oil supply means)
2d Oil supply path 21 Eccentric portion 21a Lower thrust surface member 21as Lower thrust surface (thrust bearing portion)
21b Upper thrust surface member 21bs Upper thrust surface 22 Lower shaft (shaft portion)
22a Groove portion 23 Upper shaft 23a Groove portion 3 Cylinder 3a Cylinder inner wall surface 3b Storage portion 4 Roller 4a Roller outer wall surface 4b Roller inner wall surface 5 Vane 5
6 Upper bear 6
6a Upper bear closing end face 6b Radial bearing 7 Lower bear (closing member)
7a Lower bear closed end face (thrust bearing, bearing surface)
7b Radial bearing part 8 Suction port 9 Compression chamber 10 Refrigerating machine oil 11 Stator (motor part)
12 Rotor (motor part)
13 Suction pipe 14 Discharge pipe C0 Rotation center C1 Eccentric part center M Rotation direction P Refueling start point (front end)
Q Intermediate point R End point (rear end)

Claims (10)

A crankshaft having an eccentric portion;
An electric motor section for rotating the crankshaft;
A thrust bearing portion configured to include a thrust surface of the eccentric portion and a bearing surface of a closing member that slides with the thrust surface,
The rotary compression is characterized in that the clearance between the thrust surface and the bearing surface is larger in the front end in the rotation direction than in the rear end in the rotation direction when viewed in the rotation direction of the crankshaft. Machine. 2. The rotary compressor according to claim 1, wherein the clearance between the thrust surface and the bearing surface is larger in the radial direction of the crankshaft, and the clearance is larger toward the outer side in the radial direction. 2. The rotary compressor according to claim 1, wherein the shaft portion of the crankshaft includes a recessed groove portion formed over the entire circumference in the circumferential direction of the shaft portion. 4. The rotary compressor according to claim 3, further comprising first oil supply means for supplying refrigerating machine oil to the concave groove portion. The rotary compressor according to claim 1, further comprising second oil supply means for supplying refrigeration oil to the bearing surface. The rotary compressor according to claim 1, wherein R32 refrigerant is used as the working fluid. The thrust surface has an inclined surface that inclines from the front end in the rotation direction to the rear end in the rotation direction with respect to the bearing surface when viewed in the rotation direction of the crankshaft. The rotary compressor according to claim 1. The inclination angle α of the inclined surface is
0 ° <α ≦ 0.2 °
The rotary compressor according to claim 7, wherein the rotary compressor is within the range. The thrust surface is viewed in the direction of rotation of the crankshaft.
An inclined surface that is inclined with respect to the bearing surface from a front end in the rotational direction to an intermediate portion in the rotational direction;
The rotary compressor according to claim 1, further comprising a parallel surface parallel to the bearing surface from an intermediate portion in the rotation direction to a rear end portion in the rotation direction. The thrust surface is viewed in the axial direction of the crankshaft,
The circular arc centered on the center of rotation of the crankshaft and the circular arc centered on the center of the eccentric part of the eccentric part are formed in a range surrounded by the circular arc. Rotary compressor.

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