WO2018146764A1

WO2018146764A1 - Rotary compressor

Info

Publication number: WO2018146764A1
Application number: PCT/JP2017/004706
Authority: WO
Inventors: 宏樹長澤
Original assignee: 三菱電機株式会社
Priority date: 2017-02-09
Filing date: 2017-02-09
Publication date: 2018-08-16
Also published as: JPWO2018146764A1; CN110249133A; CN110249133B; JP6771592B2

Abstract

In a rotary compressor according to the present invention, a crank shaft has at least a portion thereof arranged inside a compression mechanism section, wherein, in a cross section perpendicular to a central axis of a main shaft part of the crank shaft, the portion is at least internally constituted by a mixed body of carbon fibers and resin.

Description

Rotary compressor

The present invention relates to a rotary compressor that compresses a refrigerant, and more particularly to a rotary compressor that is reduced in size and increased in efficiency.

A conventional rotary compressor includes an electric motor having a rotor, a crankshaft connected to the rotor and transmitting a driving force of the electric motor, and a refrigerant connected to the crankshaft by the driving force transmitted from the crankshaft. A rotary type compression mechanism for compressing. The electric motor, the crankshaft, and the compression mechanism are housed in, for example, a sealed container (see, for example, Patent Document 1).

Specifically, the crankshaft includes a main shaft portion connected to the rotor of the electric motor, a sub shaft portion having a central axis coaxial with the central axis of the main shaft portion, and a space between the main shaft portion and the sub shaft portion. And an eccentric shaft portion in which the central axis is eccentric with respect to the central axis of the main shaft portion and the central axis of the auxiliary shaft portion. Generally, the crankshaft is constituted by a cast iron casting.

The compression mechanism has a cylinder chamber formed in a cylindrical shape and provided with an eccentric shaft portion, and a cylinder having a vane groove with one end communicating with the cylinder chamber. The compression mechanism is attached to the outer periphery of the eccentric shaft, and is inserted into the vane groove so as to reciprocate in a rolling piston that rotates eccentrically in the cylinder chamber by the rotation of the crankshaft. And a vane that abuts the tip and partitions the cylinder chamber into two working chambers. The compression mechanism portion closes one end portion of the cylinder chamber, and closes the first bearing portion that rotatably supports the main shaft portion, and the other end portion of the cylinder chamber, and rotates the sub-shaft portion. And a second bearing portion that is freely supported.

The part supporting the main shaft part in the first bearing part, that is, the bearing part is a slide bearing. Refrigerating machine oil is supplied between the bearing portion and the main shaft portion, for example, via an oil supply passage formed in the crankshaft. Thereby, the bearing portion rotatably supports the main shaft portion by fluid lubrication of the oil film. Similarly, the part which supports the countershaft part in the 2nd bearing part, ie, the bearing part, is a slide bearing. Refrigerating machine oil is supplied between the bearing portion and the countershaft portion via, for example, an oil supply passage formed in the crankshaft. Thereby, the said bearing part supports a countershaft part rotatably by the fluid lubrication of an oil film.

When the rotor of the motor rotates, the crankshaft connected to the rotor also rotates. As a result, in the cylinder chamber, the eccentric shaft portion of the crankshaft and the rolling piston attached to the eccentric shaft portion perform an eccentric rotational motion with respect to the central axis of the cylinder chamber. Then, the eccentric working of the eccentric shaft portion and the rolling piston in the cylinder chamber changes the volume of the two working chambers formed in the cylinder chamber.

The cylinder chamber communicates with a suction port for sucking refrigerant into the cylinder chamber and a discharge port for discharging the refrigerant from the cylinder chamber. The working chamber formed in the cylinder chamber communicates with the suction port or the discharge port in the process of changing the volume. That is, the working chamber functions as a suction chamber while communicating with the suction port, and sucks the refrigerant into the working chamber. Further, the working chamber functions as a compression chamber when it is not in communication with the suction port, and compresses the refrigerant in the working chamber as the volume decreases. The compressed refrigerant is discharged from a discharge port that communicates with a working chamber that functions as a compression chamber. As described above, two working chambers are formed in the cylinder chamber. While one working chamber functions as a suction chamber, the other working chamber functions as a compression chamber.

Since the rotary compressor is configured as described above, when the crankshaft is rotated to compress the refrigerant, a centrifugal force is generated in the eccentric shaft portion of the crankshaft. When the crankshaft is greatly deflected by the centrifugal force, scuffing occurs in the first bearing portion or the second bearing portion, and the rotary compressor fails. For this reason, in the rotary compressor described in Patent Document 1, in order to reduce the centrifugal force generated in the eccentric shaft portion, a part of the eccentric shaft portion is made of a material having a specific gravity smaller than that of the metal.

JP 2011-21854 A

In order to manufacture a small and highly efficient rotary compressor, it is necessary to make the main shaft portion and the sub shaft portion of the crankshaft where typical mechanical loss of the rotary compressor occurs as thin as possible, that is, the main shaft portion and the sub shaft portion. It is effective to reduce the diameter of the shaft portion. This is because the mechanical loss can be reduced and the input of the electric motor can be reduced while maintaining the capability of the rotary compressor. However, in the conventional rotary compressor, as described below, it is difficult to make the diameters of the main shaft portion and the sub shaft portion of the crankshaft smaller than the current state.

When the crankshaft is rotated to compress the refrigerant, the eccentric shaft portion of the crankshaft is also subjected to a load (reaction force) received by the rolling piston when the refrigerant is compressed, in addition to the centrifugal force described above. The load received by the rolling piston when compressing the refrigerant acts in a direction perpendicular to the central axis of the eccentric shaft part, in other words, in a direction perpendicular to the central axis of the main shaft part and the central axis of the sub-shaft part. To do. For this reason, the crankshaft is a center of the eccentric shaft portion with the eccentric shaft portion side end portion of the bearing portion of the first bearing portion and the eccentric shaft portion side end portion of the bearing portion of the second bearing portion as supporting points. Deflection occurs due to the above-described force acting on the eccentric shaft portion in a direction perpendicular to the axis. That is, the crankshaft bends as if a load is applied to the center of the beam supported at two points. Accordingly, the main shaft portion is inclined inside the bearing portion of the first bearing portion, and the sub-shaft portion is inclined inside the bearing portion of the second bearing portion.

When the diameter of the main shaft portion is small, the rigidity of the main shaft portion is reduced, and the inclination of the main shaft portion is increased inside the bearing portion of the first bearing portion. As a result, the oil film reaction force generated in the refrigerating machine oil filled between the bearing portion of the first bearing portion and the main shaft portion is reduced. Similarly, when the diameter of the countershaft portion is small, the rigidity of the subshaft portion is reduced, and the inclination of the countershaft portion is increased inside the bearing portion of the second bearing portion. As a result, the oil film reaction force generated in the refrigerating machine oil filled between the bearing portion of the second bearing portion and the countershaft portion is reduced.

The oil film load capacity, which is the sum of the oil film reaction force of the first bearing portion and the oil film reaction force of the second bearing portion, is based on the load supported by the first bearing portion and the second bearing portion, that is, the eccentric shaft portion of the crankshaft. It must be greater than the force acting on. When the oil film load capacity is smaller than the force acting on the eccentric shaft portion of the crankshaft, the oil film of the refrigerating machine oil partially disappears in the bearing portions of the first bearing portion and the second bearing portion, and the first bearing portion and the first bearing portion This is because the two bearing portions and the crankshaft are in metal contact. That is, adhesive wear and scuffing occur in the bearing portions of the first bearing portion and the second bearing portion, and the rotary compressor fails.

Therefore, in the conventional rotary type compressor, in order to prevent adhesive wear and scuffing from occurring in the bearing portions of the first bearing portion and the second bearing portion, the main shaft portion and the sub shaft portion of the crankshaft are prevented. It was difficult to make the diameter smaller than the current situation.

In addition, the diameters of the main shaft portion and the sub shaft portion necessary for preventing the occurrence of adhesive wear and scuffing in the bearing portions of the first bearing portion and the second bearing portion are generated in the eccentric shaft portion. Centrifugal force, load acting on the eccentric shaft portion when the refrigerant is compressed, length from the end portion on the eccentric shaft portion side of the bearing portion of the first bearing portion to the end portion on the eccentric shaft portion side of the bearing portion of the second bearing portion It is determined almost uniquely by the longitudinal elastic modulus of the crankshaft. Here, the crankshaft of the rotary compressor described in Patent Document 1 has the same configuration as the conventional one except for a part of the eccentric shaft portion. For this reason, the crankshaft of the rotary compressor described in Patent Document 1 can reduce the centrifugal force generated in the eccentric shaft portion, but the load (reaction force) that the rolling piston receives when compressing the refrigerant. The amount of bending with respect to is similar to that of the conventional crankshaft. Therefore, also in the rotary compressor described in Patent Document 1, it is difficult to make the diameters of the main shaft portion and the sub shaft portion of the crankshaft smaller than the current state.

The present invention has been made in order to solve the above-described problems, and can reduce the diameter of the main shaft portion and the sub-bearing of the crankshaft as compared with the conventional rotary compressor that is smaller and more efficient than the conventional compressor. The purpose is to provide.

A rotary compressor according to the present invention includes a motor having a rotor, a crankshaft connected to the rotor and transmitting a driving force of the motor, connected to the crankshaft, and transmitted from the crankshaft. A compression mechanism that compresses the refrigerant by a driving force, and the crankshaft includes a main shaft connected to the rotor, and a sub shaft having a central axis that is coaxial with the central axis of the main shaft. And an eccentric shaft portion that is provided between the main shaft portion and the sub shaft portion and whose center axis is eccentric with respect to the center axis of the main shaft portion and the center axis of the sub shaft portion. The compression mechanism section includes a cylinder chamber that compresses the refrigerant, the cylinder in which the eccentric shaft section is disposed in the cylinder chamber, a first bearing that rotatably supports the main shaft section, A second bearing that rotatably supports the shaft, and the crankshaft Kicking portion disposed within at least said compression mechanism portion, the central axis perpendicular to the cross section of the main shaft portion, at least internally is composed of mixture of carbon fiber and resin.

In the rotary type compressor according to the present invention, at least the portion of the crankshaft disposed inside the compression mechanism portion is composed of a mixture of carbon fiber and resin. For this reason, in the rotary type compressor according to the present invention, the longitudinal elastic modulus of the portion of the crankshaft disposed inside the compression mechanism is made larger than that of a conventional crankshaft made of cast iron casting. be able to. As a result, in the crankshaft of the rotary compressor according to the present invention, the eccentric shaft portion with the eccentric shaft portion side end portion of the first bearing and the eccentric shaft portion side end portion of the second bearing as support points. The amount of deflection due to the force acting on the eccentric shaft portion in the direction perpendicular to the central axis of the shaft is smaller than that of the conventional crankshaft. Therefore, the rotary compressor according to the present invention generates adhesive wear and scuffing in the first bearing and the second bearing even if the diameter of the main shaft portion and the sub bearing of the crankshaft is made smaller than before. This can prevent the rotary compressor from being broken.

That is, the rotary type compressor according to the present invention can reduce the diameter of the main shaft portion and the auxiliary bearing of the crankshaft as compared with the conventional one, so that typical mechanical loss of the rotary type compressor can be reduced, and the rotary type compressor is conventionally used. Smaller and more efficient.

It is a longitudinal section showing a rotary type compressor concerning an embodiment of the invention. It is a longitudinal cross-sectional view which shows the compression mechanism part of the rotary type compressor which concerns on embodiment of this invention. It is a top view which shows the compression mechanism part of the state which removed the upper bearing part in the rotary compressor which concerns on embodiment of this invention. It is a refrigerant circuit diagram which shows the refrigerating cycle circuit which uses the rotary type compressor which concerns on embodiment of this invention. It is a figure which shows the relationship between the longitudinal elastic modulus of the crankshaft part arrange | positioned inside the compression mechanism part, and the diameter of a main shaft part and a subshaft part in the rotary type compressor which concerns on this invention.

Hereinafter, in the embodiment, an example of a rotary compressor according to the present invention will be described. In the following embodiments, an example of a rotary compressor according to the present invention will be described using a vertical and hermetic rotary compressor as an example.

Embodiment.
FIG. 1 is a longitudinal sectional view showing a rotary compressor according to an embodiment of the present invention. In FIG. 1, hatching is omitted in order to make it easy to see the lead lines for the symbols.
A rotary compressor 100 according to the present embodiment includes an electric motor 2, a compression mechanism unit 3, and a crankshaft 4 that connects the electric motor 2 and the compression mechanism unit 3. Further, the rotary compressor 100 according to the present embodiment is a hermetic compressor. For this reason, the electric motor 2, the compression mechanism portion 3, and the crankshaft 4 are accommodated in the sealed container 1. The rotary compressor 100 is a vertical rotary compressor as described above, and the electric motor 2 is disposed above the compression mechanism section 3 in the sealed container 1.

The electric motor 2 includes a stator 21 and a rotor 22 that is rotated by a magnetic force generated by the stator 21. The stator 21 includes a coil around which a conductive wire is wound, and generates a magnetic force when the coil is energized. The coil of the stator 21 is connected to a terminal 23 provided in the rotary compressor 100, and is energized from the outside of the rotary compressor 100 via the terminal 23. The rotor 22 includes a secondary conductor or a permanent magnet formed of an aluminum bar or the like, and rotates in response to the magnetic force generated by the coil of the stator 21.

The compression mechanism unit 3 compresses the low-pressure refrigerant gas sucked into the compression mechanism unit 3 by the driving force of the electric motor 2 transmitted from the crankshaft 4 and discharges the high-pressure refrigerant gas into the sealed container 1. The sealed container 1 is filled with compressed high-temperature and high-pressure refrigerant gas. On the other hand, refrigerating machine oil for lubricating the compression mechanism 3 is stored below the bottom of the sealed container 1, that is, at the bottom.

The crankshaft 4 is connected to the rotor 22 and the compression mechanism unit 3 of the electric motor 2 and transmits the driving force of the electric motor 2. The crankshaft 4 includes a main shaft portion 41, a sub shaft portion 42, and an eccentric shaft portion 43. In the present embodiment, the main shaft portion 41, the eccentric shaft portion 43, and the auxiliary shaft portion 42 are provided in this order from the top to the bottom. That is, the main shaft portion 41 is provided on one side of the eccentric shaft portion 43 in the axial direction, and the auxiliary shaft portion 42 is provided on the other side of the eccentric shaft portion 43 in the axial direction. In other words, the eccentric shaft portion 43 is provided between the main shaft portion 41 and the sub shaft portion 42. Each of the main shaft portion 41, the sub shaft portion 42, and the eccentric shaft portion 43 has a substantially cylindrical shape. The central axis of the auxiliary shaft portion 42 is provided coaxially with the central axis of the main shaft portion 41. On the other hand, the central axis of the eccentric shaft portion 43 is eccentric with respect to the central axes of the main shaft portion 41 and the auxiliary shaft portion 42. That is, when the main shaft portion 41 and the sub shaft portion 42 rotate around these central axes, the eccentric shaft portion 43 rotates eccentrically. The rotor 22 of the electric motor 2 is fixed (connected) to the main shaft portion 41 by, for example, shrink fitting or press fitting. A cylindrical-shaped rolling piston 32 is slidably attached to the outer peripheral portion of the eccentric shaft portion 43.

FIG. 2 is a longitudinal sectional view showing a compression mechanism portion of the rotary compressor according to the embodiment of the present invention. FIG. 3 is a plan view showing the compression mechanism portion with the upper bearing portion removed in the rotary compressor according to the embodiment of the present invention. That is, FIG. 3 is a view of the compression mechanism portion 3 with the upper bearing portion 33 removed, as viewed from the AA direction shown in FIG. In FIG. 2, unlike FIG. 1, the crankshaft 4 is also shown in cross section.

The compression mechanism unit 3 includes a cylinder 31, a bearing 33 b that rotatably supports the main shaft portion 41 of the crankshaft 4, and a bearing 34 b that rotatably supports the subshaft portion 42 of the crankshaft 4. Here, the bearing 33b corresponds to the first bearing of the present invention. The bearing 34b corresponds to the second bearing of the present invention.

The cylinder 31 has a cylinder chamber 36 that compresses the refrigerant. The central axis of the cylinder chamber 36 is arranged coaxially with the central axes of the main shaft portion 41 and the subshaft portion 42 of the crankshaft 4. In the present embodiment, the cylinder chamber 36 is formed in the cylinder 31, for example, in a cylindrical shape with both ends in the vertical direction opened. For this reason, the opening above the cylinder chamber 36 is closed by the flat closing member 33a. The opening below the cylinder chamber 36 is closed by a flat closing member 34a. In the present embodiment, in addition to the eccentric shaft portion 43 of the crankshaft 4, the rolling piston 32 attached to the outer peripheral portion of the eccentric shaft portion 43 is also arranged in the cylinder chamber 36 of the cylinder 31. Yes. Therefore, when the crankshaft 4 rotates, the eccentric shaft portion 43 and the rolling piston 32 rotate eccentrically with respect to the central axis of the cylinder chamber 36 in the cylinder chamber 36 of the cylinder 31.
Here, the closing member 33a corresponds to the first closing member of the present invention. The closing member 34a corresponds to the second closing member of the present invention.

In this embodiment, the cylinder 31 has a vane groove 37 formed along the radial direction of the cylinder chamber 36. One end of the vane groove 37 communicates with the cylinder chamber 36, and the other end of the vane groove 37 communicates with the back pressure chamber 38. A vane 35 having a substantially rectangular parallelepiped shape is inserted into the vane groove 37. The vane 35 can reciprocate in the vane groove 37 and reciprocates while sliding in the vane groove 37. The back pressure chamber 38 is provided with a spring (not shown). The vane 35 is pushed out from the vane groove 37 toward the cylinder chamber 36 of the cylinder 31, and the tip of the vane 35 is brought into contact with the outer peripheral surface of the rolling piston 32. Yes.

That is, the vane 35 divides the cylinder chamber 36, more specifically, a space formed by the inner peripheral surface of the cylinder chamber 36 and the outer peripheral surface of the rolling piston 32 into two working chambers. One of these working chambers becomes a suction chamber 36a for sucking refrigerant into the working chamber, as will be described later. The other of these working chambers is a compression chamber 36b that compresses the refrigerant in the working chamber. That is, the vane 35 divides the cylinder chamber 36 into a suction chamber 36a and a compression chamber 36b. The cylinder chamber 36 compresses the refrigerant in the compression chamber 36b.

Above the cylinder 31, a bearing 33b is provided. The bearing 33b is a sliding bearing and has a cylindrical space that is open at both ends in the vertical direction. The main shaft portion 41 is inserted into the space so as to penetrate from one opening portion to the other opening portion. And the bearing 33b supports the main-shaft part 41 rotatably. In the present embodiment, the bearing 33 b is integrally formed with the closing member 33 a as the upper bearing portion 33. In other words, the upper bearing portion 33 includes the closing member 33a and the bearing 33b. Specifically, the bearing 33 b extends from the closing member 33 a in the direction opposite to the cylinder 31, that is, in the direction of the rotor 22. The upper bearing portion 33 is fixed to the upper surface of the cylinder 31 with, for example, bolts.
Here, the upper bearing portion 33 corresponds to the first bearing portion of the present invention.

Refrigerator oil is supplied between the bearing 33 b of the upper bearing portion 33 and the main shaft portion 41. Thereby, the bearing 33b of the upper bearing portion 33 rotatably supports the main shaft portion 41 by fluid lubrication of the oil film. In the present embodiment, the refrigerating machine oil stored at the bottom of the sealed container 1 passes through the

oil supply passages

51 and 52 formed in the crankshaft 4 to form the bearing 33b of the upper bearing portion 33 and the main shaft portion 41. Supplied in between.

Similarly, a bearing 34 b is provided below the cylinder 31. The bearing 34b is a sliding bearing and has a cylindrical space that is open at both ends in the vertical direction. The auxiliary shaft portion 42 is inserted into the space so as to penetrate from one opening portion to the other opening portion. And the bearing 34b supports the subshaft part 42 rotatably. In the present embodiment, the bearing 34 b is integrally formed with the closing member 34 a as the lower bearing portion 34. In other words, the lower bearing portion 34 includes the closing member 34a and the bearing 34b. Specifically, the bearing 34 b extends from the closing member 34 a in the direction opposite to the cylinder 31, that is, in the direction of the bottom of the sealed container 1. The lower bearing portion 34 is fixed to the lower surface of the cylinder 31 with, for example, bolts.
Here, the lower bearing portion 34 corresponds to the second bearing portion of the present invention.

Refrigerator oil is supplied between the bearing 34 b of the lower bearing portion 34 and the countershaft portion 42. Thereby, the bearing 34b of the lower bearing part 34 supports the countershaft part 42 rotatably by fluid lubrication of an oil film. In the present embodiment, the refrigerating machine oil stored at the bottom of the sealed container 1 passes through the

oil supply passages

51 and 53 formed in the crankshaft 4, and the bearing 34 b and the subshaft portion 42 of the lower bearing portion 34. Supplied during.

The cylinder 31 is formed with a suction port 39 for sucking refrigerant gas into the cylinder chamber 36 from the outside of the sealed container 1. The suction port 39 communicates with a working chamber serving as a suction chamber 36 a among the two working chambers partitioned by the vane 35. Further, the upper bearing portion 33 is provided with a discharge port (not shown) for discharging the compressed refrigerant gas to the outside of the cylinder chamber 36. The discharge port communicates with the working chamber serving as the compression chamber 36b among the two working chambers partitioned by the vane 35.

A discharge valve is provided at the discharge port of the upper bearing portion 33. The discharge valve closes until the refrigerant gas compressed in the compression chamber 36b reaches a predetermined pressure, and opens to discharge the high-temperature and high-pressure refrigerant gas into the sealed container 1 when the pressure exceeds the predetermined pressure. Thereby, the discharge timing of the refrigerant gas discharged from the compression chamber 36b is controlled.

Referring again to FIG. 1, the refrigerant gas discharged into the sealed container 1 flows toward the discharge pipe 11 above the sealed container 1, and is sent out from the discharge pipe 11 to the outside of the sealed container 1. At that time, the refrigerant gas flows upward through a gap between the stator 21 and the rotor 22 of the electric motor 2 or an air hole provided in the rotor 22.

The suction muffler 101 provided outside the sealed container 1 is connected to the suction port 39 via the suction pipe 12. Low-pressure refrigerant gas and liquid refrigerant are mixedly sent to the rotary compressor 100 from an external circuit to which the rotary compressor 100 is connected. When the liquid refrigerant flows into the compression mechanism unit 3 and is compressed, the compression mechanism unit 3 fails. For this reason, the suction muffler 101 separates the liquid refrigerant and the refrigerant gas. Then, only the refrigerant gas is sent to the compression mechanism unit 3.

FIG. 4 is a refrigerant circuit diagram showing a refrigeration cycle circuit using the rotary compressor according to the embodiment of the present invention.
As shown in FIG. 4, a condenser 102, an expansion valve 103, and an evaporator 104 are provided outside the rotary compressor 100 to constitute a refrigeration cycle circuit. That is, the refrigeration cycle circuit is an annular circuit in which the discharge pipe 11, the condenser 102, the expansion valve 103, the evaporator 104, and the suction muffler 101 of the rotary compressor 100 are connected by piping. As the refrigerant circulates in the refrigeration cycle circuit, air or water exchanges heat with the refrigerant in the condenser 102 and the evaporator 104, and heat energy is conveyed. Such a refrigeration cycle circuit is used in a heat pump device such as an air conditioner.

Note that a four-way valve 105 is provided in the refrigeration cycle circuit shown in FIG. The four-way valve 105 switches so as to reverse the route through which the refrigerant circulates. Specifically, the four-way valve 105 is configured such that the rotary compressor 100, the evaporator 104, and the expansion valve 103 pass through the refrigerant flow in the order of the rotary compressor 100, the condenser 102, the expansion valve 103, the evaporator 104 and the suction muffler 101. Then, switching is performed so that the refrigerant flows in the order of the condenser 102 and the suction muffler 101. Thereby, conveyance of heat energy can be reversed. That is, when the refrigeration cycle circuit is used as an air conditioner, the cooling operation and the heating operation can be switched. When the forward path is reversed, the condenser 102 functions as an evaporator, and the evaporator 104 functions as a condenser.

Next, the operation of the compression mechanism unit 3 will be described.
When the rotor 22 of the electric motor 2 rotates, the crankshaft 4 connected to the rotor 22 also rotates. Thus, in the cylinder chamber 36, the eccentric shaft portion 43 of the crankshaft 4 and the rolling piston 32 attached to the eccentric shaft portion 43 perform an eccentric rotational motion with respect to the central axis of the cylinder chamber 36. . Then, due to the eccentric rotational movement of the eccentric shaft portion 43 and the rolling piston 32 in the cylinder chamber 36, the working chamber communicating with the suction port 39 functions as the suction chamber 36a and sucks low-pressure refrigerant gas.

The working chamber into which the low-pressure refrigerant gas is sucked from the suction port 39 moves in the cylinder chamber 36 by the eccentric rotational movement of the eccentric shaft portion 43 and the rolling piston 32, and the communication with the suction port 39 is cut off. . Thereafter, the working chamber functions as the compression chamber 36b. Furthermore, when the eccentric shaft portion 43 and the rolling piston 32 are eccentrically rotated, the volume of the working chamber is reduced and the sucked refrigerant gas is compressed. As the eccentric rotational movement of the eccentric shaft portion 43 and the rolling piston 32 proceeds, the working chamber communicates with the discharge port.

When the working chamber and the discharge port communicate with each other and the discharge valve closing the discharge port opens the discharge port, the high-pressure refrigerant gas in the working chamber is discharged into the sealed container 1 through the discharge port. Further, when the eccentric shaft portion 43 and the rolling piston 32 are eccentrically rotated, the communication between the working chamber and the discharge port is cut off and the communication with the suction port 39 is resumed. Thereafter, the working chamber functions as the suction chamber 36a.

The series of operations described above is performed while the eccentric shaft portion 43 and the rolling piston 32 make one rotation in the cylinder chamber 36. When one of the two working chambers sucks the refrigerant gas, the other working chamber discharges the refrigerant gas. Therefore, the working chamber in which the suction port 39 communicates with the vane 35 and sucks the low-pressure refrigerant gas becomes the suction chamber 36a of the low-pressure space, and the working chamber in which the refrigerant is compressed without communicating with the suction port 39. It becomes the compression chamber 36b of a high pressure space.

Since the rotary compressor 100 is configured as described above, centrifugal force is generated in the eccentric shaft portion 43 of the crankshaft 4 when the crankshaft 4 is rotated to compress the refrigerant. Further, when the crankshaft 4 is rotated to compress the refrigerant, the eccentric shaft portion 43 of the crankshaft 4 receives a load (reverse force) applied to the rolling piston 32 when the refrigerant is compressed, in addition to the centrifugal force described above. Force) also works. The load that the rolling piston 32 receives when compressing the refrigerant is perpendicular to the central axis of the eccentric shaft portion 43, in other words, perpendicular to the central axis of the main shaft portion 41 and the central axis of the auxiliary shaft portion 42. Acting in any direction.

For this reason, the crankshaft 4 is subjected to the eccentric shaft 43 by these forces acting on the eccentric shaft 43 side end of the bearing 33b of the upper bearing 33 and the eccentric shaft of the bearing 34b of the lower bearing 34. Deflection occurs with the end portion on the side of the portion 43 as a support point. That is, the crankshaft bends as if a load is applied to the center of the beam supported at two points. As a result, the main shaft portion 41 is inclined inside the bearing 33 b of the upper bearing portion 33, and the auxiliary shaft portion 42 is inclined inside the bearing 34 b of the lower bearing portion 34.

When the diameter of the main shaft portion 41 is small, the rigidity of the main shaft portion 41 is lowered, and the inclination of the main shaft portion 41 is increased inside the bearing 33b of the upper bearing portion 33. As a result, the oil film reaction force generated in the refrigerating machine oil filled between the bearing 33b of the upper bearing portion 33 and the main shaft portion 41 is reduced. Similarly, when the diameter of the sub-shaft portion 42 is small, the rigidity of the sub-shaft portion 42 is reduced, and the inclination of the sub-shaft portion 42 is increased inside the bearing 34 b of the lower bearing portion 34. As a result, the oil film reaction force generated in the refrigerating machine oil filled between the bearing 34b of the lower bearing portion 34 and the countershaft portion 42 is reduced.

The oil film load capacity, which is the sum of the oil film reaction force of the bearing 33b of the upper bearing portion 33 and the oil film reaction force of the bearing 34b of the lower bearing portion 34, is supported by the bearing 33b of the upper bearing portion 33 and the bearing 34b of the lower bearing portion 34. That is, it is necessary to be larger than the force acting on the eccentric shaft portion 43. When the oil film load capacity becomes smaller than the force acting on the eccentric shaft portion 43, the oil film of the refrigerating machine oil partially disappears in the bearing 33b of the upper bearing portion 33 and the bearing 34b of the lower bearing portion 34, and the upper bearing portion 33. This is because the bearing 33b and the bearing 34b of the lower bearing portion 34 and the crankshaft are in metal contact. That is, adhesive wear and scuffing occur in the bearing 33b of the upper bearing portion 33 and the bearing 34b of the lower bearing portion 34, and the rotary compressor 100 breaks down.

Therefore, the centrifugal force generated in the eccentric shaft portion 43, the load acting on the eccentric shaft portion 43 when the refrigerant is compressed, the bearing 34b of the lower bearing portion 34 from the end portion on the eccentric shaft portion 43 side of the bearing 33b of the upper bearing portion 33. It is necessary to determine the diameters of the main shaft portion 41 and the sub shaft portion 42 based on the length to the end portion on the eccentric shaft portion 43 side.

Here, in order to manufacture a small and highly efficient rotary compressor 100, the main shaft portion 41 and the sub shaft portion 42 of the crankshaft 4 where typical mechanical loss of the rotary compressor 100 occurs are made as thin as possible. That is, it is effective to reduce the diameters of the main shaft portion 41 and the sub shaft portion 42. This is because the mechanical loss can be reduced and the input of the electric motor 2 can be reduced while maintaining the capability of the rotary compressor 100. However, when the crankshaft 4 is made of cast iron as in the conventional case, it is difficult to reduce the diameters of the main shaft portion 41 and the subshaft portion 42 as compared with the conventional case.

Therefore, in the rotary compressor 100 according to the present embodiment, at least the inside of at least the portion of the crankshaft 4 disposed inside the compression mechanism portion 3 in the cross section perpendicular to the central axis of the main shaft portion 41 is carbon. It comprised with the mixture 45 of the fiber and resin. In addition, if the longitudinal elastic modulus of the mixture 45 can be made larger than the cast iron used for the conventional crankshaft, the carbon fiber and resin which comprise the mixture 45 will not be specifically limited. Ductile cast iron generally used for the crankshaft of current rotary compressors has a longitudinal elastic modulus of 150 GPa. For example, by mixing the following carbon fibers and resin at an appropriate ratio to form the mixture 45, the longitudinal elastic modulus can be set to 640 GPa to 900 GPa.
(1) Carbon fiber: Pitch-based carbon fiber having a fiber length of 50 μm to 500 μm and an ultra high modulus type.
(2) Resin: General-purpose thermoplastic resin such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT).

For example, as shown in FIG. 2, at least a portion of the crankshaft 4 that is disposed inside the compression mechanism portion 3 has an outer peripheral portion made of metal in a cross section perpendicular to the central axis of the main shaft portion 41, and the inside It is comprised with the mixture 45 of carbon fiber and resin. In other words, a mixture of carbon fiber and resin is provided along the central axis direction of the main shaft portion 41 at least inside the portion of the crankshaft 4 disposed inside the compression mechanism portion 3. The crankshaft 4 having such a configuration is manufactured, for example, by inserting a mixture 45 of carbon fiber and resin as a core rod into the crankshaft 4 made of cast iron. In the crankshaft 4 configured in this way, the sliding portions with the

bearings

33b and 34b are cast iron as in the conventional case. For this reason, the longitudinal elastic modulus of the crankshaft 4 can be increased while the sliding characteristics with the

bearings

33b and 34b are the same as the conventional one. Here, in the present embodiment, in the cross section perpendicular to the central axis of the main shaft portion 41, at least the portion of the crankshaft 4 that is disposed inside the compression mechanism portion 3 has the inside diameter of the auxiliary shaft portion 42. It is composed of a mixture 45 with a diameter of less than 90%. By constituting the crankshaft 4 in this way, the deformation of the cast iron portion can be suppressed, so that the cast iron and the mixture 45 can be prevented from peeling off.

Further, for example, the crankshaft 4 may be configured such that all of the portion of the crankshaft 4 disposed inside the compression mechanism section 3 is composed of a mixture 45 of carbon fiber and resin. The crankshaft 4 having such a configuration, for example, after an approximate shape is formed by an injection molding die, polishes an outer peripheral portion or the like inserted into the bearing 33b of the upper bearing portion 33 and the bearing 34b of the lower bearing portion 34. Manufactured by. In the crankshaft 4 configured as described above, the longitudinal elastic modulus of the crankshaft 4 can be increased as compared with the case where cast iron is present on the outer peripheral portion of the mixture 45.

As described above, at least a part of at least a portion of the crankshaft 4 disposed inside the compression mechanism section 3 is configured by the carbon fiber and resin mixture 45, whereby the compression mechanism section 3 in the crankshaft 4 is configured. The longitudinal elastic modulus of the portion arranged in the interior can be made larger than that of a conventional crankshaft made of cast iron casting. Thus, in the crankshaft 4 of the rotary compressor 100 according to the present embodiment, the eccentric shaft portion 43 side end of the bearing 33 b of the upper bearing portion 33 and the eccentric shaft of the bearing 34 b of the lower bearing portion 34. With the end portion on the side of the portion 43 as a support point, the amount of deflection due to the force acting on the eccentric shaft portion 43 in a direction perpendicular to the central axis of the eccentric shaft portion 43 is reduced as compared with the conventional crankshaft. Therefore, in the rotary compressor 100 according to the present embodiment, even if the diameters of the main shaft portion 41 and the sub shaft portion 42 of the crankshaft 4 are made smaller than before, the bearing 33b and the lower bearing portion 34 of the upper bearing portion 33. It is possible to prevent adhesive wear and scuffing from occurring in the bearing 34b, and to prevent the rotary compressor 100 from failing.

That is, the rotary compressor 100 according to the present embodiment can reduce the diameters of the main shaft portion 41 and the subshaft portion 42 of the crankshaft 4 as compared with the prior art, so that typical mechanical loss of the rotary compressor can be reduced. The rotary compressor 100 can be made smaller and more efficient than conventional ones.

FIG. 5 is a diagram showing the relationship between the longitudinal elastic modulus of the crankshaft portion disposed inside the compression mechanism portion and the diameters of the main shaft portion and the subshaft portion in the rotary compressor according to the present invention.
Here, the horizontal axis of FIG. 5 indicates the longitudinal elastic modulus of the portion of the crankshaft 4 disposed inside the compression mechanism section 3. Further, the vertical axis in FIG. 5 indicates the diameters of the main shaft portion 41 and the sub shaft portion 42 that are necessary when the longitudinal elastic modulus shown in the horizontal axis in FIG. The required diameters of the main shaft portion 41 and the sub shaft portion 42 indicate that the main shaft portion 41 can prevent adhesion wear and scuffing from occurring in the bearing 33b of the upper bearing portion 33 and the bearing 34b of the lower bearing portion 34. And the minimum diameter of the countershaft portion 42. The diameters of the main shaft portion 41 and the sub shaft portion 42 shown on the vertical axis in FIG. 5 are the diameters of the main shaft portion and the sub shaft portion of a duct shaft made of ductile cast iron generally used in current rotary type compressors. Is shown as “1”.

Further, in FIG. 5, the necessary diameters of the main shaft portion and the sub shaft portion were calculated as follows. Specifically, a model is assumed in which a cylindrical beam is simply supported (supported rotatably) at two points, and a concentrated load of a specified magnitude is applied to the center position between the support points of the beam. Then, while changing the longitudinal elastic modulus of the beam, the beam diameter at which the deflection angle becomes the specified angle was calculated. In addition, the specified angle of the bending angle is allowed in the rotary compressor 100, and the inclination of the main shaft portion 41 inside the bearing 33b of the upper bearing portion 33 and the sub shaft portion 42 inside the bearing 34b of the lower bearing portion 34 are allowed. Determined based on slope.

The ductile cast iron generally used for the crankshaft of the current rotary compressor has a longitudinal elastic modulus of 150 GPa. As shown in FIG. 5, in the crankshaft 4 according to the present embodiment, if the longitudinal elastic modulus of the portion arranged inside the compression mechanism portion 3 is 300 GPa, with respect to the crankshaft made of ductile cast iron, The diameters of the main shaft portion 41 and the sub shaft portion 42 can be reduced by 15.9%. For example, when the outer peripheral portion is made of ductile cast iron having a longitudinal elastic modulus of 150 GPa and the inside is the mixture 45 having a longitudinal elastic modulus of 800 GPa, the portion disposed inside the compression mechanism portion 3 in the crankshaft 4 is configured. By setting the area ratio of the cross-sectional area of the main shaft portion 41 and the sub-shaft portion 42 to the cross-sectional area of the mixture 45 to 3:10, the longitudinal elasticity of the portion of the crankshaft 4 disposed inside the compression mechanism portion 3 is set. The coefficient can be 300 GPa. For example, when the diameter of the main shaft portion 41 and the sub shaft portion 42 is 21 mm, the diameter of the mixture 45 having a longitudinal elastic modulus of 800 GPa is set to 13.7 mm, so that the crankshaft 4 is disposed inside the compression mechanism portion 3. The longitudinal elastic modulus of the portion that is present can be set to 300 GPa.

Further, as shown in FIG. 5, in the crankshaft 4 according to the present embodiment, if the longitudinal elastic modulus of the portion arranged inside the compression mechanism portion 3 is set to 600 GPa, the crankshaft made of ductile cast iron Thus, the diameters of the main shaft portion 41 and the sub shaft portion 42 can be reduced by 29.3%. For example, the longitudinal elastic modulus of the portion disposed inside the compression mechanism portion 3 in the crankshaft 4 can be set to 600 GPa by configuring all the portions disposed inside the compression mechanism portion 3 with the mixture 45. .

¡Crankshaft sliding loss accounts for approximately 10% of the total loss generated in the rotary compressor. For this reason, reducing the diameters of the main shaft portion 41 and the sub shaft portion 42 as in the present embodiment can greatly contribute to miniaturization and high efficiency of the rotary compressor 100.

As described above, the rotary compressor 100 according to the present embodiment is connected to the electric motor 2 having the rotor 22, the crankshaft 4 connected to the rotor 22 and transmitting the driving force of the electric motor 2, and the crankshaft 4. And a compression mechanism unit 3 that compresses the refrigerant by the driving force transmitted from the crankshaft 4. The crankshaft 4 includes a main shaft portion 41 connected to the rotor 22, a sub shaft portion 42 having a central axis coaxial with the central axis of the main shaft portion 41, and the main shaft portion 41 and the sub shaft portion 42. And an eccentric shaft portion 43 whose central axis is eccentric with respect to the central axis of the main shaft portion 41 and the central axis of the auxiliary shaft portion 42. The compression mechanism section 3 includes a cylinder chamber 36 that compresses the refrigerant, a cylinder 31 in which the eccentric shaft portion 43 is disposed in the cylinder chamber 36, a bearing 33b that rotatably supports the main shaft portion 41, And a bearing 34b that rotatably supports the countershaft portion 42. In the crankshaft 4, at least a portion of the crankshaft 4 disposed inside the compression mechanism portion 3 is composed of a mixture 45 of carbon fiber and resin at least in the cross section perpendicular to the central axis of the main shaft portion 41. .

For this reason, the rotary compressor 100 according to the present embodiment has a longitudinal elastic modulus of a portion of the crankshaft 4 arranged in the compression mechanism portion 3 in the crankshaft 4 compared to a conventional crankshaft made of cast iron. Can also be increased. Thus, in the crankshaft 4 of the rotary compressor 100 according to the present embodiment, the eccentric shaft portion 43 side end portion of the bearing 33b and the eccentric shaft portion 43 side end portion of the bearing 34b are used as supporting points. The amount of deflection due to the force acting on the eccentric shaft portion 43 in a direction perpendicular to the central axis of the eccentric shaft portion 43 is smaller than that of the conventional crankshaft. Therefore, the rotary compressor 100 according to the present embodiment can reduce the diameters of the main shaft portion 41 and the subshaft portion 42 of the crankshaft 4 as compared with the conventional one, so that typical mechanical loss of the rotary compressor can be reduced. The rotary compressor 100 can be a rotary compressor that is smaller and more efficient than conventional ones.

For example, at least a portion of the crankshaft 4 that is disposed inside the compression mechanism portion 3 has a cross section perpendicular to the central axis of the main shaft portion 41, an outer peripheral portion made of metal, and an inner portion made of a mixture 45. Yes. In the crankshaft 4 configured in this way, the longitudinal elastic modulus of the crankshaft 4 can be increased while the sliding characteristics with the

bearings

33b and 34b are the same as the conventional one. At this time, for example, at least a portion of the crankshaft 4 disposed inside the compression mechanism portion 3 is composed of a mixture 45 having a diameter of less than 90% of the diameter of the subshaft portion 42. By constituting the crankshaft 4 in this way, it is possible to prevent the metal and the mixture 45 from peeling off.

Also, for example, all of the portions of the crankshaft 4 disposed inside the compression mechanism portion 3 are composed of the mixture 45. In the crankshaft 4 configured as described above, the longitudinal elastic modulus of the crankshaft 4 can be increased as compared with the case where metal is present on the outer peripheral portion of the mixture 45.

Further, for example, at least a portion of the crankshaft 4 disposed inside the compression mechanism 3 has a longitudinal elastic modulus of 300 GPa or more.

1 sealed container, 11 discharge pipe, 12 suction pipe, 2 motor, 21 stator, 22 rotor, 23 terminal, 3 compression mechanism part, 31 cylinder, 32 rolling piston, 33 upper bearing part, 33a closing member, 33b bearing, 34 Lower bearing portion, 34a closing member, 34b bearing, 35 vane, 36 cylinder chamber, 36a suction chamber, 36b compression chamber, 37 vane groove, 38 back pressure chamber, 39 suction port, 4 crankshaft, 41 main shaft portion, 42 secondary Shaft part, 43 eccentric shaft part, 45 mixture, 51 oil supply path, 52 oil supply path, 53 oil supply path, 100 rotary compressor, 101 suction muffler, 102 condenser, 103 expansion valve, 104 evaporator, 105 four-way valve .

Claims

An electric motor having a rotor;
A crankshaft connected to the rotor and transmitting a driving force of the electric motor;
A compression mechanism that is connected to the crankshaft and compresses the refrigerant by the driving force transmitted from the crankshaft;
With
The crankshaft is
A main shaft portion connected to the rotor, a sub shaft portion having a center axis coaxially arranged with a central axis of the main shaft portion, and a main shaft portion provided between the main shaft portion and the sub shaft portion. An eccentric shaft portion that is eccentric with respect to the central axis of the main shaft portion and the central axis of the auxiliary shaft portion;
Have
The compression mechanism is
A cylinder chamber that compresses the refrigerant, and a cylinder in which the eccentric shaft portion is disposed in the cylinder chamber;
A first bearing that rotatably supports the main shaft portion;
A second bearing rotatably supporting the countershaft portion;
Have
A portion of the crankshaft disposed at least inside the compression mechanism portion is
A rotary compressor in which at least the inside is composed of a mixture of carbon fiber and resin in a cross section perpendicular to the central axis of the main shaft portion.
A portion of the crankshaft disposed at least inside the compression mechanism portion is
2. The rotary compressor according to claim 1, wherein an outer peripheral portion is made of metal and an inside is made of the mixture in a cross section perpendicular to the central axis of the main shaft portion.
A portion of the crankshaft disposed at least inside the compression mechanism portion is
The rotary type compressor according to claim 2, wherein the inside is constituted by the mixture having a diameter of less than 90% of the diameter of the countershaft portion.
2. The rotary compressor according to claim 1, wherein all of the portions of the crankshaft disposed inside the compression mechanism section are configured by the mixture.
The rotary compressor according to any one of claims 1 to 4, wherein at least a portion of the crankshaft disposed inside the compression mechanism section has a longitudinal elastic modulus of 300 GPa or more.
The cylinder chamber is formed in the cylinder in a shape in which both ends are open,
The compression mechanism is
A first bearing member having a first closing member that closes one opening of the cylinder chamber, and the first bearing;
A second bearing member having a second closing member for closing the other opening of the cylinder chamber, and the second bearing;
The rotary compressor according to any one of claims 1 to 5, further comprising:
The cylinder has a vane groove with one end communicating with the cylinder chamber,
The compression mechanism is
A rolling piston attached to an outer peripheral portion of the eccentric shaft portion and eccentrically rotating in the cylinder chamber by rotation of the crankshaft;
A vane which is inserted into the vane groove so as to be freely reciprocable, a tip part abuts on an outer peripheral surface of the rolling piston, and partitions the cylinder chamber into a suction chamber for sucking refrigerant and a compression chamber for compressing refrigerant;
The rotary compressor according to any one of claims 1 to 6, further comprising: