JP2005264784A - Reciprocating refrigerant compressor and refrigeration system - Google Patents

Abstract

[PROBLEMS] To reduce vibration caused by a step-out stop due to a compression load and a reciprocating motion of a piston in a decrease in rotational inertia force of a rotating body, particularly at a low operating rotational speed, in an inverter control. Prevent fatigue failure.
A connecting means 115a includes an eccentric part 110 that is eccentrically connected in a direction opposite to a main shaft part 109 and a pair of pistons 114a and 114b that reciprocate in compression chambers 119a and 119b arranged in parallel. , 115b, the pistons 114a, 114b alternately perform compression during one rotation of the crankshaft 108. Therefore, the compressor can be reduced by suppressing the maximum load torque associated with refrigerant gas compression in the compression element 106. Can be prevented, and vibrations generated by the reciprocating motion of the pistons 114a and 114b can be offset and greatly reduced.
[Selection] Figure 1

Description

  The present invention relates to an inverter-controlled reciprocating refrigerant compressor used mainly for household electric refrigerator-freezers and the like.

  In recent years, the demand for the global environment has been increasing, and there is a strong demand for reduction of power consumption in refrigerators and other refrigeration cycle apparatuses. In particular, in a reciprocating refrigerant compressor that uses an inverter drive circuit to change the operating speed, the power consumption can be reduced by operating at a low speed, while at the same time increasing the efficiency at a low speed. In addition, low vibration is a problem.

  Conventionally, as this type of reciprocating refrigerant compressor, there has been an improvement in which lubricating oil is stably supplied in order to obtain stable efficiency during low-speed operation (see, for example, Patent Document 1).

  The conventional reciprocating refrigerant compressor will be described below with reference to the drawings.

  FIG. 7 shows a longitudinal sectional view of a conventional reciprocating refrigerant compressor described in Patent Document 1. As shown in FIG.

  In FIG. 7, lubricating oil 2 is stored at the bottom of the sealed container 1. The electric element 3 includes a stator 4 and a rotor 5, and drives the compression element 6. The electric element 3 is rotated by an inverter drive circuit (not shown), and the coil 4 is greatly reduced by adopting a salient pole concentrated winding for the stator 4. Is placed in the iron core to achieve small size and high efficiency. Further, the compression element 6 is elastically supported by a suspension spring 7 fixed to the lower part of the hermetic container 1.

  Next, details of the compression element 6 will be described below. The compression element 6 is disposed above the electric element 3. The crankshaft 8 of the compression element 6 includes a main shaft portion 9 and an eccentric portion 10. The main shaft portion 9 is rotatably supported by a bearing portion 12 of a block 11, and the rotor 5 is fixed to the lower end. An oil pump 13 immersed in the lubricating oil 2 is formed. A connecting means 15 for connecting to the piston 14 and a balance weight 16 are fixed to the eccentric portion 10. The piston 14 is reciprocally inserted into the cylinder 17 of the block 11 and forms a compression chamber 19 together with the cylinder 17 and the valve plate 18. The connecting means 15 connects the eccentric portion 10 and the piston 14. The valve plate 18 is fixed to the block 11 together with the suction muffler 21 by the cylinder head 20.

  The operation of the reciprocating refrigerant compressor configured as described above will be described below.

  When the electric element 3 is energized, the rotor 5 rotates the crankshaft 8 by the magnetic field generated in the stator 4. By the rotation of the main shaft portion 9, the eccentric motion of the eccentric portion 10 is transmitted to the piston 14 via the connecting means 15. The piston 14 reciprocates in the cylinder 17 and introduces the refrigerant returned from a known refrigeration cycle (not shown) outside the sealed container 1 into the compression chamber 19 through the suction muffler 21 in the sealed container 1. Compress. During this compression movement, unbalanced vibration due to the reciprocating movement of the piston 14 and eccentric movement of the eccentric portion 10 of the crankshaft 8 occur, but are balanced by the balance weight 16. Then, the compressed refrigerant is sent to a known refrigeration cycle (not shown) outside the sealed container 1 via a discharge pipe (not shown). Further, as the crankshaft 8 rotates, the oil pump 13 sucks the lubricating oil 2, guides the inside of the crankshaft 8 upward, and is injected onto the compression element 6 so that each sliding surface of the compression element 6 is moved. Lubricate.

An inverter drive circuit (not shown) detects the rotation of the rotor 5 and drives the electric element 3 while adjusting the output so as to have a predetermined rotation speed. Normally, the output of the inverter drive circuit is constant during one revolution, but the load torque driven by the electric element 3 fluctuates during one revolution and is large during compression and small during suction. As a result, the rotational speed of the rotor 5 also changes during one rotation. However, since the rotational inertia force of the rotor 5 and the crankshaft 8 is large near the commercial frequency and the fluctuation amount is small compared to the absolute value of the rotational speed, the load Torque fluctuation was rarely a problem.
JP 2003-65236 A

  However, in the above-described conventional configuration, the rotational inertia force of the rotor 5 and the crankshaft 8 decreases as the operating rotational speed decreases. For this reason, the fluctuation of the rotation speed during one rotation of the rotor 5 also increases. Further, since it is impossible to completely cancel the vibration generated by the reciprocating motion of the piston 14 by the balance weight 16, the vibration due to the reciprocating motion of the piston 14 is easily transmitted from the suspension spring 7 to the hermetic container 1, and the compressor There is a problem that vibration increases. These phenomena are particularly noticeable at a very low frequency of 20 Hz or less, the rotational speed of the rotor 5 is greatly reduced during compression, and the compressor stops when the electric element 3 steps out without overcoming the load. There is a problem that noise generated from the compressor and the refrigeration apparatus increases due to the possibility and vibration due to the reciprocating movement of the piston 14, and the piping of the refrigeration apparatus is fatigued and destroyed due to vibration, causing the refrigerant to leak. These problems have been a barrier for realizing a compressor that can cope with a wide range of refrigeration capacities using a lower operation speed such as 20 Hz or lower as a means for reducing the power consumption of the refrigerator.

  An object of the present invention is to solve the above-described conventional problems, and to achieve stable operation of a compressor with a wide range of operation rotation speed, and to reduce vibration and to realize a highly reliable refrigeration apparatus. To do.

  In order to solve the above-described conventional problems, a reciprocating refrigerant compressor of the present invention includes a main shaft portion and a crankshaft provided with an eccentric portion that is eccentrically arranged in opposite directions with respect to the main shaft portion, and A block having a main bearing that rotatably supports the main shaft portion, a support portion that supports the stator, and a cylinder portion that is formed by arranging a pair of compression chambers in parallel; Refrigerant gas is provided with a pair of pistons that reciprocate and a pair of connecting means for connecting the eccentric portion and the piston, respectively, and the compression mechanism alternately compresses twice in one rotation of the electric element. The maximum value of the load torque that accompanies the intake, compression, and discharge processes of the compressor is reduced, reducing the compression load of the compressor, making it difficult to stop the step-out, enabling stable operation, and reciprocating movement of the piston. Ri vibration generated is to be canceled.

  In the reciprocating refrigerant compressor of the present invention, a pair of pistons alternately perform a compression action in parallel with the rotation of the crankshaft, thereby preventing the compressor from stepping out and ensuring stable operation of the compressor. In addition, the vibration of the compressor can be greatly reduced.

  The invention according to claim 1 is driven by an inverter at a plurality of operating frequencies including a rotational speed less than a commercial power supply frequency, and is driven by a lubricating oil, an electric element including a stator and a rotor, and a compression driven by the electric element. The compression element includes a main shaft portion and an eccentric portion that is eccentric to each other in the opposite direction with respect to the main shaft portion, and an oil supply device that supplies the lubricating oil in the vicinity of the lower end. A block having a crankshaft, a support portion that has a main bearing that rotatably supports the main shaft portion and supports the stator, and a cylinder portion that is formed by arranging a pair of compression chambers in parallel. A pair of pistons that reciprocate in the compression chamber, and a pair of connecting means for connecting the eccentric portion and the piston, respectively, and a pair of pistons with respect to rotation of the crankshaft. The tons alternately perform the compression action, which suppresses the maximum load torque during the refrigerant gas suction, compression, and discharge processes, reduces the compressor compression load, makes it difficult to stop step-out, and ensures stable operation. Furthermore, the vibration accompanying the reciprocating motion in the compression operation can be canceled and the vibration can be greatly reduced.

  A second aspect of the present invention is the reciprocating refrigerant compressor according to the first aspect of the present invention, wherein the compression element is disposed under the electric element, and the compression element is close to the lubricating oil of the compressor. Therefore, it is not necessary to supply lubricating oil to the upper part of the compressor, it becomes easy to supply oil to the compression element, the sliding surface of the compression element can be easily lubricated, and the rotor By having the oil supply passage below, the lubricating oil is not applied to the stator of the electric element, so that the deterioration of the winding, the leakage of current, and the like can be reduced.

  According to a third aspect of the present invention, in the reciprocating refrigerant compressor according to the second aspect of the present invention, the oil supply device is a centrifugal pump having one end immersed in lubricating oil, and the compression mechanism is located below the compressor. Because of the arrangement, it is possible to reliably supply oil to the sliding surface of the compression mechanism even with a simple and inexpensive structure.

  According to a fourth aspect of the present invention, in the reciprocating refrigerant compressor according to any one of the first to third aspects of the present invention, the block is configured by fixing the cylinder portion and the support portion which are made of separate parts. Thus, the piston can be easily inserted into the cylinder portion, and the assembly of the compression element can be facilitated.

  The invention according to claim 5 is the reciprocating refrigerant compressor according to any one of claims 1 to 4, wherein the connecting portion on the piston side of the connecting means is formed by a ball joint, By using a ball joint for the piston-side coupling, the ball joint can rotate in all directions even if the cylinder assembly accuracy is poor, so the piston is tilted with respect to the inner wall of the compression chamber. Therefore, abnormal wear can be reduced.

  The invention according to claim 6 is the reciprocating refrigerant compressor according to any one of claims 1 to 5, wherein the crankshaft is formed on the same axis as the main shaft portion with the eccentric portion interposed therebetween. A second block having a shaft portion and having a sub-bearing for pivotally supporting the sub-shaft portion is fixed to the block. By supporting the crankshaft by both the main bearing and the sub-bearing, it is transmitted to the crankshaft by the connecting means. By supporting the load during compression on both sides of the eccentric portion, the crankshaft is prevented from being twisted, and abnormal wear can be reduced.

  According to a seventh aspect of the present invention, in the reciprocating refrigerant compressor according to any one of the first to sixth aspects of the present invention, a salient pole concentrated winding is used for the stator forming the electric element. The rotor is made of rare earth magnet material arranged in the iron core. As the electric element becomes smaller, the rotational inertia force becomes smaller, the load on the electric element increases, and the load torque may not be able to be overcome. Despite being provided with a pair of pistons, by alternately performing the compression action, the maximum value of the load torque in the process of refrigerant gas suction, compression and discharge is reduced, and stable operation is obtained. The electric element can be reduced in size.

  The invention according to claim 8 is the reciprocating refrigerant compressor of the invention according to any one of claims 1 to 7, wherein the refrigerant gas to be compressed is R600a. Although the required cylinder volume is increased compared to the refrigerant, since a pair of pistons is provided, the cylinder volume per cylinder can be reduced, the refrigerant can be sucked and discharged smoothly, and the compression efficiency can be improved.

  A ninth aspect of the present invention is the reciprocating refrigerant compressor according to any one of the first to eighth aspects, wherein the reciprocating refrigerant compressor includes an operating frequency of 20 r / sec or less, particularly a rotational inertial force. In ultra-low speed operation, which reduces the load on the electric elements and reduces the maximum value of the load torque, it is possible to prevent out-of-step stop, and further, by reducing the rotational speed, the compressor Energy input can be reduced and energy saving can be realized.

  A tenth aspect of the present invention is the reciprocating refrigerant compressor according to any one of the first to ninth aspects, wherein the ratio of the maximum rotational speed to the minimum rotational speed is 3 or more. An appropriate refrigeration capacity is obtained with respect to cycle load fluctuations, and energy saving can be realized.

  According to an eleventh aspect of the present invention, a reciprocating refrigerant compressor according to any one of the first to tenth aspects is used in a refrigeration apparatus including a compressor, a condenser, an expander, and an evaporator. By using a compressor with reduced rotor rotational speed fluctuation and vibration due to piston reciprocation, the noise of the refrigeration system and the fatigue failure of the piping caused by the compressor vibration can be reduced. A refrigeration apparatus with low noise and high reliability can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a longitudinal sectional view of a reciprocating refrigerant compressor according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. FIG. 3 is a characteristic diagram showing piston displacement according to the present invention. FIG. 4 is a characteristic diagram showing the pressure of the compression element according to the present invention. FIG. 5 is a characteristic diagram showing the load torque in the compression chamber of the present invention.

  1 and 2, the lubricating oil 102 is stored in the inner bottom portion of the sealed container 101, and the electric element 103 and the compression element 106 driven by the electric element 103 are accommodated. For example, a hydrocarbon system having a low warming coefficient such as R600a. The refrigerant is filled.

  The electric element 103 is fixed above the block 111 and has a stator 104 employing salient pole concentrated windings connected to an inverter drive circuit (not shown), and a magnet material made of rare earth such as neodymium ( (Not shown) is arranged in the iron core, and is composed of a rotor 105 fixed to the main shaft portion 109. As a result, the electric element 103 is highly efficient and downsized, and particularly has a low thickness, and the rotational inertia force of the rotor 105 is small.

  Further, the electric element 103 is driven by an inverter and has a minimum rotation speed of 15 r / sec and a maximum rotation speed of 75 r / sec, thereby setting the ratio of the maximum rotation speed to the minimum rotation speed to 5, Operate in a wide range.

  Next, details of the compression element 106 will be described below.

  The block 111 is disposed below the electric element 103, and is configured by fixing a cylinder portion 123 made of a separate part to the support portion 122. The cylinder portion 123 is formed as a pair by arranging substantially cylindrical cylinders 117a and 117b in parallel. Further, the support portion 122 forms a main bearing 112 that rotatably supports the main shaft portion 109 of the crankshaft 108, and the stator 104 is fixed upward.

  The second block 124 is elastically supported by a suspension spring 107 fixed to the lower portion of the hermetic container 101, and forms a sub-bearing 126 that rotatably supports the sub-shaft portion 125 of the crankshaft 108, and is compressed. Fixed to the block 111 below the element 106.

  The crankshaft 108 includes a main shaft portion 109 into which the rotor 105 is press-fitted and fixed, an eccentric portion 110a, 110b that is eccentrically connected to the main shaft portion 109 in opposite directions, and an eccentric portion 110a, 110b. 109 and a sub-shaft portion 125 formed on the same axis. The main shaft portion 109 and the sub shaft portion 125 are rotatably supported by the block 111 and the second block 124 via the main bearing 112 and the sub bearing 126, and the rotor 105 is fixed to the upper end of the main shaft portion 109. Is done. Further, an oil supply device 127 tilted with respect to the axis of the main shaft 109 is formed inside the lower end of the crankshaft 108 so as to open into the lubricating oil 102. Further, with respect to the axis of the main shaft 109, An oil supply passage 128 is formed so as to be farther away as it goes upward, with one end communicating with the oil supply device 127 and the other end opening below the rotor 105. The lubricating oil 102 is conveyed to the bearings and the eccentric parts 110a and 110b from the opening part in the middle of the oil supply passage 128 and the opening part at the upper end.

  The eccentric portions 110a and 110b are connected to the pair of pistons 114a and 114b by a pair of connecting means 115a and 115b in which connecting portions on the pistons 114a and 114b side are formed by ball joints.

  The pistons 114a and 114b are reciprocally inserted into the cylinders 117a and 117b arranged in parallel with the cylinder portion 123 of the block 111, and are arranged in parallel with a pair of cylinders 117a and 117b arranged in parallel with the valve plate 118. A pair of compression chambers 119a and 119b are formed. The valve plate 118 is fixed to the cylinder portion 123 of the block 111 together with the suction muffler 121 by the cylinder head 120.

  About the reciprocating refrigerant compressor comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  When the electric element 103 is energized from the inverter drive circuit, the rotor 105 rotates together with the crankshaft 108 by the magnetic field generated in the stator 104. As the main shaft portion 109 and the sub shaft portion 125 rotate, the eccentric portions 110a and 110b rotate eccentrically in opposite directions, and this eccentric motion is converted into reciprocating motion via the connecting means 115a and 115b. By reciprocating the cylinders 117a and 117b in which the cylinders 114a and 114b are arranged in parallel, the refrigerant gas in the sealed container 101 is sucked into the compression chambers 119a and 119b, and a predetermined compression operation is performed alternately.

  In the suction stroke accompanying this compression operation, the refrigerant gas in the sealed container 101 is alternately sucked into the compression chambers 119a and 119b via the suction muffler 121, compressed, and then passed through a discharge pipe (not shown). To a known refrigeration cycle (not shown) outside the sealed container 101.

  In addition, since the oil supply device 127 and the oil supply passage 128 are inclined so as to move upward with respect to the main shaft portion 109, the lubricating oil 102 stored in the sealed container 101 is centrifuged as the crankshaft 108 rotates. It is sucked up by the force and travels along the oil supply path 127 to move the sliding portions of the crankshaft 108, the sliding portions of the pistons 114a and 114b and the compression chambers 119a and 119b, and the sliding portions of the connecting means 115a and 115b. Lubricate.

  Here, in the present embodiment, since the eccentric portions 110a and 110b are eccentric in opposite directions, the pistons 114a and 114b always reciprocate alternately at the same speed. Therefore, the vibrations generated by the reciprocating motions of the respective pistons 114a and 114b cancel each other, and the vibrations of the compressor can be greatly reduced.

  Further, in the present embodiment, the compression element 106 is disposed below the electric element 103, and it is not necessary to supply the lubricating oil 102 up to the upper part of the compressor. Oiling of 102 becomes easy. Further, in this embodiment, since the compression element 106 is disposed below the compressor, the sliding surface of the compression element 106 can be sufficiently lubricated even if a centrifugal pump is used, and the structure is simple. An inexpensive oil supply mechanism can be provided. In addition, since the electric element 103 is disposed above the compression element 106, the stator 104 of the electric element 103 is not exposed to the lubricating oil 102, so that the windings of the stator 104 are deteriorated, the current Leakage etc. can be remarkably reduced.

  Further, in the present embodiment, the block 111 is configured by fixing the support portion 122 and the cylinder portion 123, thereby facilitating the insertion of the pistons 114a and 114b into the cylinder portion 123. Assembling is easy.

  Further, by connecting the pistons 114a and 114b to the eccentric portions 110a and 110b of the crankshaft 108, the connecting portions on the pistons 114a and 114b side of the connecting means 115a and 115b are ball joints, thereby supporting the support portion 122 of the block 111. Since the ball joint is rotatable in all directions even when the assembly accuracy of the cylinder portion 123 is poor, the pistons 114a and 114b are prevented from being inclined with respect to the inner walls of the compression chambers 119a and 119b. It is possible to reduce abnormal wear.

  Further, by supporting the crankshaft 108 with both the main bearing 112 of the block 111 and the sub-bearing 126 of the second block 124, the compression load transmitted to the crankshaft 108 by the connecting means 115a and 115b is supported on both sides. This prevents twisting and can reduce abnormal wear.

  Next, with reference to FIGS. 3, 4, and 5, the reduction in the rotational speed fluctuation of the rotor 105 due to the rotor 105 and the load torque in a series of compressor operations will be described.

  FIG. 3 shows displacements from the top dead center of the respective pistons 114a and 114b. When the compression chamber 119a is at the top dead center, the compression chamber 119b is at the bottom dead center, and conversely, when the compression chamber 119a is at the bottom dead center, the compression chamber 119b is at the top dead center. In addition, since there are two compression chambers in order to obtain the same ability as in the conventional case, if the cylinder volume is the same as one cylinder, the excitation force of one piston is greatly reduced.

  Therefore, when one of the pistons 114a is at the top dead center, the other piston 114b is at the bottom dead center. Therefore, as shown in FIG. 4, the same pressure as in the prior art can be obtained twice by each of the pistons 114a and 114b. . As a result, as shown in FIG. 5, the load torque fluctuation caused by the gas compression and the inertial force caused by the fluctuation of the operation speed by the inverter drive circuit also occurs twice, but the maximum value of the load torque is the conventional value. About half of the

  As a result, the load fluctuation is reduced by half even though the inertial force of rotation including the rotor 105 and the crankshaft 108 is extremely small in ultra-low speed operation such as 15 r / sec. And the fluctuation in the rotational speed of the rotor 105 is small. That is, although the rotational inertia force decreases as the electric element 103 becomes smaller and the load on the electric element 103 increases, the maximum value of the load torque is reduced, so that stable operation can be obtained. it can. As a result, the electric element 103 is difficult to step out and can rotate stably, and the vibration of the compressor due to uneven rotation can be reduced.

  Further, in the ultra-low speed operation of 15 r / sec, the control side senses the overcurrent generated by the delay of the rotor 105 with respect to the rotating magnetic field created by the stator 104 even if the step-out is not reached, and issues a stop command. Although it was easy to stop, this phenomenon almost never happened. For this reason, low-speed operation can be realized by enabling ultra-low speed operation, and a high energy-saving effect can be obtained. In the present embodiment, the lower rotational speed can be reduced to 15 r / sec. The rotational speed ratio with 75 r / sec, which has been implemented, can be very wide as 5.

  On the other hand, recent refrigerator-freezers for home use have dramatically improved thermal insulation performance, and the ratio of required refrigeration capacity between stable operation and load application has increased. However, the refrigerating capacity of reciprocating refrigerant compressors has increased. Since it is generally proportional to the rotational speed of the electric element, according to the present embodiment, it is possible to cope with the increase in the ratio of the necessary refrigeration capacity, and as described above, an extremely high energy saving effect can be obtained. .

  In this embodiment, R600a having a low environmental load is used as the refrigerant. However, R600a has a lower refrigeration capacity per unit flow rate than an HFC refrigerant such as R134a, and the cylinder volume needs to be relatively large. However, according to the present embodiment, the cylinder volume per cylinder of each of the compression chambers 119a and 119b can be reduced to about half, so that the suction and discharge of the refrigerant can be made smooth and the compression efficiency can be improved. It is suitable for.

  In addition, since there are two compression chambers in order to obtain the same capacity as the conventional one, if the cylinder volume is the same as that of one cylinder, the excitation force of one piston is greatly reduced, and the pistons 114a and 114b are always Since the reciprocating motion is alternately performed at the same speed, the vibration accompanying the reciprocating motion of the pistons 114a and 114b is canceled out, and a low-vibration compressor can be realized even if R600a, which has a significant vibration increase in a single cylinder, is used as a refrigerant. Can do.

(Embodiment 2)
FIG. 6 is a configuration diagram of the refrigeration apparatus according to the second embodiment.

  In FIG. 6, the compressor 150 is fluidly coupled to a condenser 151, a dryer 152, an expander 153, and an evaporator 154 by piping such as brazing. The compressor 150 is described in the first embodiment of the present invention.

  The operation and action of the refrigeration apparatus configured as described above will be described below.

  The compressor 150 sucks low-pressure and low-temperature refrigerant vapor and compresses it into high-pressure and high-temperature vapor. The high-temperature and high-pressure refrigerant vapor discharged from the compressor 150 enters the condenser 151 and is cooled by air to become a high-pressure refrigerant liquid. Thereafter, the moisture in the refrigeration apparatus is removed by the dryer 152, and the pressure of the high-pressure refrigerant is reduced due to the resistance of the narrow valve path of the expander 153, and the low-pressure and low-temperature liquid refrigerant is formed. to go into. While the low-pressure and low-temperature liquid refrigerant flows through the evaporator 154, the low-temperature and low-temperature liquid refrigerant evaporates while taking ambient heat, and becomes low-pressure and low-temperature refrigerant vapor, which is sucked into the suction pipe of the compressor 150.

  In the present embodiment as described above, since the compressor 150 is the compressor 150 in the first embodiment, the compression load and vibration of the compressor 150 are reduced, and the excitation force to the refrigeration apparatus is reduced. Therefore, the abnormal noise generated when the refrigeration apparatus resonates with the compressor 150 can be greatly reduced. In addition, all the components of the refrigeration system are joined by piping by welding such as brazing, but if stress due to large vibrations is repeatedly applied to the brazed part, cracks occur due to fatigue and refrigerant leaks. There is a possibility. However, in the present embodiment, since the vibration of the compressor 150 is low, generation of cracks due to fatigue of the piping of the refrigeration apparatus is suppressed, breakage hardly occurs, and a highly reliable refrigeration apparatus can be provided.

  As described above, the reciprocating refrigerant compressor and the refrigeration apparatus according to the present invention can reduce the compression load of the compressor, enable stable operation without stepping out, and greatly reduce vibration generated by the piston. The present invention can be widely applied not only to household electric refrigerator-freezers but also to inverter-controlled reciprocating compressors used in air conditioners, vending machines, other refrigeration devices, and the like.

The longitudinal cross-sectional view of the reciprocating refrigerant compressor in Embodiment 1 of this invention AA sectional view of FIG. Piston displacement characteristic diagram of the reciprocating refrigerant compressor of the present invention Pressure characteristic diagram in the compression chamber of the reciprocating refrigerant compressor of the present invention Load torque characteristic diagram of compression element of reciprocating refrigerant compressor of the present invention The block diagram of the freezing apparatus in Embodiment 2 of this invention A longitudinal sectional view of a conventional reciprocating refrigerant compressor

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Airtight container 102 Lubricating oil 103 Electric element 104 Stator 105 Rotor 106 Compression element 108 Crankshaft 109 Main shaft part 110a, 110b Eccentric part 111 Block 112 Main bearing 114a, 114b Piston 115a, 115b Connection means 119a, 119b Compression chamber 122 Support Part 123 Cylinder part 124 Second block 125 Sub shaft part 126 Sub bearing 127 Oil supply device 128 Oil supply passage 150 Compressor 151 Condenser 153 Expander 154 Evaporator

Claims (11)

Inverter-driven at a plurality of operating frequencies including a rotational speed lower than the commercial power supply frequency, and contains lubricating oil, an electric element composed of a stator and a rotor, and a compression element driven by the electric element in a sealed container. The compression element includes a main shaft portion and a crank shaft provided with an oil supply device for supplying the lubricating oil in the vicinity of a lower end of the main shaft portion and an eccentric portion eccentric to each other in the opposite direction to the main shaft portion, and the main shaft portion. A block having a main bearing rotatably supported and supporting the stator, a block having a cylinder portion formed by arranging a pair of compression chambers in parallel, and a pair reciprocating in the compression chamber And a pair of connecting means for connecting the eccentric part and the piston, respectively, a reciprocating refrigerant compressor. The reciprocating refrigerant compressor according to claim 1, wherein the compression element is disposed under the electric element and has an oil supply passage below the rotor. The reciprocating refrigerant compressor according to claim 2, wherein one end of the oil supply device is immersed in the lubricating oil and is a centrifugal pump. The reciprocating refrigerant compressor according to claim 1 or 2, wherein the block is configured by fixing a cylinder portion and a support portion which are formed of separate parts. The reciprocating refrigerant compressor according to any one of claims 1 to 4, wherein a coupling portion on a piston side of the coupling means is formed by a ball joint. 6. The crankshaft according to any one of claims 1 to 5, wherein the crankshaft is provided with a secondary shaft portion formed coaxially with the main shaft portion with an eccentric portion interposed therebetween, and a second block having a secondary bearing that pivotally supports the secondary shaft portion is fixed to the block. A reciprocating refrigerant compressor according to claim 1. The reciprocating refrigerant compressor according to any one of claims 1 to 6, wherein the rotor forming the electric element has a magnet material made of rare earth disposed in the iron core. The reciprocating refrigerant compressor according to any one of claims 1 to 7, wherein the refrigerant gas to be compressed is R600a. The reciprocating refrigerant compressor according to any one of claims 1 to 8, comprising an operating frequency of 20r / sec or less. The reciprocating refrigerant compressor according to any one of claims 1 to 9, wherein a ratio of the maximum rotational speed to the minimum rotational speed is 3 or more. A refrigerating apparatus comprising a compressor, a condenser, an expander, and an evaporator, wherein the reciprocating refrigerant compressor according to claim 1 is used as the compressor.

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