JP2019019701A - Compressor - Google Patents

Abstract

To attain reliability improvement and efficiency improvement by suppressing vibration of a pump part consisting of a cylinder and a piston or the like in a low operation frequency lower than a commercial power supply frequency.SOLUTION: The present invention relates to a compressor comprising: a rotor which rotates a crankshaft; an eccentric part which is positioned at an upper side of the crankshaft; a piston which moves reciprocally; a connecting rod which connects the piston with the eccentric part; a piston pin which connects the piston with the connecting rod; and a balance weight which is provided at an upper side of the eccentric part and symmetrically with respect to the eccentric part with a rotation axis of the crankshaft defined as a center. The compressor also comprises a rotor balance weight which is provided in the rotor and symmetrically with respect to the eccentric part with the rotation axis of the crankshaft defined as a center.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a compressor.

  The demand for higher efficiency is high in recent refrigeration and refrigeration equipment, etc., and the hermetic compressor installed in the same way is also from low operating frequency below commercial power frequency to high operating frequency above commercial power frequency for high efficiency as well. In the low operating frequency range that affects high efficiency, the vibration of the compressor itself tends to deteriorate, and it also affects performance deterioration due to increased sliding loss. It is necessary to.

  As background art of this technical field, there is one described in Japanese Patent Laid-Open No. 2005-133684 (Patent Document 1). This patent document 1 discloses a hermetic reciprocating compressor that uses a piston pin to connect a piston and a connecting rod. The piston is designed to reduce vibration of a compressor that is operated at a low operating frequency lower than a commercial power supply frequency. Lightening is described.

JP 2005-133684 A

  In order to reduce the vibration of the compressor, Patent Document 1 discloses that in addition to reducing the weight of the piston, the centrifugal force generated by the piston, etc. with respect to the center of the crankshaft rotation shaft and the center of the bearing length that supports the crankshaft rotation shaft In order to improve the unbalance of the moment of the centrifugal force generated by the piston or the like with respect to the position, a balance weight is provided at the upper end of the pin portion serving as the eccentric portion of the crankshaft.

  However, in the hermetic reciprocating compressor using a piston pin described in Patent Document 1, the parallelism and perpendicularity in the sliding portion of the connecting rod, the piston, and the cylinder affect the sliding loss with respect to the inclination of the crankshaft. In addition, when operating at a low operating frequency lower than the commercial power supply frequency, the shaft tilt increases due to the gyro effect (a phenomenon in which the posture is less likely to be disturbed when the object rotates), which further increases the sliding loss. There was a problem of inviting.

In addition, the piston is not only in a state of being incorporated in the compressor, but also has a limitation in weight reduction because it needs to have rigidity for ensuring dimensional accuracy during machining.
Therefore, when operating at a low operating frequency less than the commercial power supply frequency, compression is not possible due to insufficient weight reduction of the piston and imbalance improvement due to centrifugal force and moment of centrifugal force with only the balance weight at the top of the pin. It is difficult to reduce machine vibration.

  The object of the present invention is to solve the above-mentioned conventional problems, not only when operating at a low operating frequency less than the commercial power supply frequency, which is less susceptible to the gyro effect, but also when starting from stop and when stopping from operation In order to achieve low vibration and high efficiency by changing the setting range based on the design of unbalance due to centrifugal force and the moment of centrifugal force so as to achieve low vibration and low sliding loss.

  The present invention made in view of the above circumstances includes a rotor for rotating a crankshaft, an eccentric portion located above the crankshaft, a reciprocating piston, a connecting rod for connecting the piston and the eccentric portion, A compressor comprising: a piston pin that couples a piston and the connecting rod; and a balance weight that is provided above the eccentric part and that is provided symmetrically with respect to the eccentric part about the rotation axis of the crankshaft. And a rotor balance weight provided in the rotor and symmetrically with respect to the eccentric portion around the rotation axis of the crankshaft.

  The present invention is a hermetic reciprocating compressor that uses a piston pin for connecting a piston and a rod, and when operating at a low operating frequency less than a commercial power frequency that is less susceptible to the gyro effect, transitions from an operating state to a stopped state. In this case, there is an effect that low vibration and low sliding loss can be satisfied even when starting from a stopped state.

The principal part sectional drawing related to the imbalance of the compressor of the Example of this invention. Sectional drawing of the compressor of the Example of this invention.

  Embodiments of a hermetic compressor according to the present invention will be described below with reference to the accompanying drawings. The same components are denoted by the same reference numerals, and the same description will not be repeated.

  FIG. 1 is a front view of a structure including a piston and a crankshaft of the compressor of this embodiment, and FIG. 2 is a cross-sectional view of the compressor of this embodiment.

  Lubricating oil 2 (refrigerating machine oil) is stored in the bottom of the sealed container 1, and an electric element 5 including a rotor 3 and a stator 4 and a compression element 6 driven by the electric element 5 are accommodated. Yes.

  The compression element 6 includes a crankshaft 7 having a main shaft portion 7a to which the rotor 3 is fixed and an eccentric shaft portion (pin portion) 7b, a cylinder 9a for forming a compression chamber 8 in which a compression process is performed, and the like. Block 9, piston 10 that reciprocates in cylinder 9a, connecting rod 11 and piston pin 12 that connect piston 10 and pin portion 7b, and main bearing 9b that is provided on cylinder block 9 and supports main shaft portion 7a of crankshaft 7 In order to reduce vibration due to unbalance in reciprocating motion such as a thrust ball bearing (thrust bearing) 13 disposed on the thrust surface side of the main bearing 9b and supporting the crankshaft 7 in the axial direction, and a piston 10 during the compression process. And provided at the upper end of the pin portion 7b and at a position symmetrical to the pin portion 7b around the rotation axis of the main shaft portion 7a. And it is made of such Erareru balance weight 14.

  When the crankshaft 7 is rotated by the electric element 5, the piston 10 reciprocates via the eccentric shaft portion 7 b, the connecting rod 11 and the piston pin 12. The compression operation (compression process) is performed by the reciprocating motion of the piston 10.

  In the structure in which the piston 10 and the connecting rod 11 are connected using the piston pin 12, the connecting rod 11 generated with the inclination of the crankshaft 7 generated when the crankshaft 7 rotates with respect to the clearance between the main bearing 9b and the main shaft portion 7a, In order to suppress the sliding loss between the piston 10 and the cylinder 9a, it is important to manage the parallelism and the squareness that are the machining dimensional accuracy. In addition, when operating at a low operating frequency less than the commercial power supply frequency where the inclination of the crankshaft 7 is less likely to be affected by the gyro effect, when changing from the operating state to the stopped state, and when starting from the stopped state, vibration occurs. In addition to the increase, sliding loss also increases. In addition to the piston pin structure, there is a ball joint structure in which the piston side and the connecting rod are connected in a spherical shape, but the ball joint structure can absorb the shaft tilt by the spherical shape. There is no increase in sliding loss.

The mass of the piston 10 including the piston pin 12 is MP, the mass of the connecting rod 11 is MR, the mass of the pin portion 7b is MS, and the mass of the balance weight 14 is MB.
Also, RP is the eccentric amount that is the distance between the rotation axis center of the main shaft portion 7a and the central axis of the pin portion 7b, RS is the radial distance between the rotation shaft center of the main shaft portion 7a and the center of gravity of the pin portion 7b, and the main shaft portion 7a. The distance in the radial direction of the center of gravity between the center of the rotation shaft and the balance weight 14 is RB, the distance in the vertical direction between the center position of the bearing length of the main bearing 9b and the piston pin 12 and the center of gravity of the piston 10 is LP, and the main bearing 9b. LS is the vertical distance between the center position of the bearing length and the center of gravity of the pin portion 7b, LR is the vertical distance between the center position of the bearing length of the main bearing 9b and the center of gravity of the connecting rod 11, and the main bearing 9b The vertical distance between the center position of the bearing length and the center of gravity of the balance weight 14 is LB.

  In addition to the balance weight 14, the compressor of the present embodiment includes a rotor balance weight 3a provided at a position symmetrical to the pin portion 7b around the upper end of the rotor 3 and the rotation axis of the main shaft portion 7a. Yes. The rotor balance weight 3a may be provided on the side surface or the lower end portion of the rotor 3, but it is preferable that the rotor balance weight 3a is positioned on the upper end side in order to fit a coefficient described later within a suitable range relatively easily.

Let MW be the mass of the rotor balance weight 3a, and let RW be the radial distance between the rotation axis center of the main shaft portion 7a and the center of gravity of the rotor balance weight 3a.
When the center of gravity of the front rotor balance weight 3a is above the center of the bearing length of the main bearing 9b, the vertical distance between the center of the bearing length of the main bearing 9b and the center of gravity of the rotor balance weight 3a LWP, and when the center of gravity position of the rotor balance weight 3a is below the center position of the bearing length of the main bearing 9b, the vertical position between the center position of the bearing length of the main bearing 9b and the center of gravity of the rotor balance weight 3a The distance in the direction is denoted as LWN.

  At this time, in the piston 10 (including the piston pin 12), the connecting rod 11, the pin portion 7b, the balance weight 14, and the rotor balance weight 3a when the main shaft portion 7a rotates, the center position of the bearing length of the main bearing 9b is set. The relationship between the centrifugal force and the moment as a reference is shown in Equations 1 and 2. Which of Equations 1 and 2 is used depends on the position of the rotor balance weight 3a. The coefficients C1 and C2 are preferably values close to 1.0, for example, 0.90 to 1.10.

  Further, in the piston 10 (including the piston pin 12), the connecting rod 11, the pin portion 7b, the balance weight 14, and the rotor balance weight 3a when the main shaft portion 7a is started from the stop state and when the operation state is changed to the stop state, The relationship of the centrifugal force with reference to the rotation axis center of the main shaft portion 7a is shown in Equation 3. The coefficient C3 is preferably a value close to 1.0, for example, 0.90 to 1.10.

  In this way, when operating at a low operating frequency less than the commercial power supply frequency, which is less susceptible to the gyro effect, low vibration and low slippage are obtained even when transitioning from the operating state to the stopped state and when starting from the stopped state. Dynamic loss can be realized.

  Here, Equation 1, Equation 2, and Equation 3 will be described. In Equations 1 and 2, the numerator and denominator are separated by the difference in the direction in which the moment is generated with reference to the center position of the bearing length of the bearing 9b. Even if the numerator and denominator are reversed, the direction of the moment reference is There is no problem as a formula because it only changes.

  In Equation 3, the numerator and denominator are separated by the difference in the direction of the centrifugal force generated on the left and right with respect to the center of the rotation axis of the main shaft portion 7a. There is no problem as a formula because it only changes. In addition, Formulas 1 and 2 are mathematical formulas that exclude the distance related to the moment.

  According to the present embodiment, operation with low vibration and low sliding loss is possible even at 13 to 17 Hz, which is a low operating frequency region below the commercial power supply frequency.

  The values included in Equations 1 to 3 will be described more specifically. Since the piston 10 (including the piston pin 12) only reciprocates with respect to the rotation axis of the main shaft portion 7a, the mass is reduced to ½, and the connecting rod 11 reciprocates and rotates with respect to the main shaft portion 7a. Since both are included, the reciprocation is separated from the rotation. The reciprocation is halved in mass, and the center of gravity of the connecting rod is between the center of gravity of the piston 10 (including the piston pin 12) and the pin portion 7b. Therefore, the number 5 is set in consideration of the influence of 1/2, and the amount of rotation is the number 6 where the mass is 1/2.

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Refrigerating machine oil 3 Rotor 3a Rotor balance weight 4 Stator 5 Electric element 6 Compression element 7 Crankshaft 7a Main shaft part 7b Eccentric part (pin part)
8 Compression Chamber 9 Cylinder Block 9a Cylinder 9b Main Bearing 10 Piston 11 Connecting Rod 12 Piston Pin 13 Thrust Ball Bearing (Thrust Bearing)
14 Balance weight

Claims (4)

A rotor for rotating the crankshaft;
An eccentric part located above the crankshaft;
A reciprocating piston;
A connecting rod connecting the piston and the eccentric portion;
A piston pin connecting the piston and the connecting rod;
A balance weight provided on the upper side of the eccentric part and provided symmetrically with respect to the eccentric part around the rotation axis of the crankshaft,
A compressor having a rotor balance weight provided in the rotor and provided symmetrically with respect to the eccentric portion around a rotation axis of the crankshaft. The mass of the piston including the piston pin is MP,
MR of the connecting rod mass,
The mass of the eccentric part is MS,
The mass of the balance weight is MB,
RP, the amount of eccentricity that is the distance between the center of rotation of the crankshaft and the center of the eccentric part,
The radial distance between the rotation axis center and the center of gravity of the eccentric portion is RS,
A radial distance between the center of the rotation axis and the center of gravity of the balance weight is RB,
LP is the distance in the vertical direction between the center position of the bearing length in the vertical direction and the center of gravity of the piston including the piston pin,
The vertical distance between the center position of the bearing length and the center of gravity of the eccentric portion is LS,
The vertical distance between the center position of the bearing length and the center of gravity of the rod is LR,
The vertical distance between the center position of the bearing length and the center of gravity of the balance weight is LB,
The mass of the rotor balance weight is MW,
The radial distance between the rotation axis center and the center of gravity of the rotor balance weight is RW,
When the center of gravity position of the rotor balance weight is above the center position of the bearing length, the vertical distance between the center position of the bearing length and the center of gravity of the rotor balance weight is LWP,
When the center of gravity position of the rotor balance weight is below the center position of the bearing length, when the vertical distance between the center position of the bearing length and the center of gravity of the rotor balance weight is LWN,
Centrifugal force with reference to the center position of the bearing length in the piston including the piston pin when the crankshaft rotates, the connecting rod, the eccentric part, the balance weight, and the rotor balance weight; 2. The hermetic compressor according to claim 1, wherein the coefficient C1 of Formula 1 or the coefficient C2 of Formula 2 indicating the relationship of moments is 0.90 to 1.10.

The piston including the piston pin when the crankshaft starts from a stopped state and when the crankshaft transitions from a running state to a stopped state, the connecting rod, the pin portion, the balance weight, and the rotor balance weight, 3. The hermetic compression according to claim 1, wherein a coefficient C3 of Formula 3 indicating a relationship of centrifugal force with respect to a center of a rotation axis of the crankshaft is 0.90 to 1.10. Machine.

  The hermetic compressor according to any one of claims 1 to 3, wherein an operating frequency of the rotor can be 13 to 17 Hz.

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