JP2003293953A - Reciprocating hermetic motor compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reciprocating hermetic motor compressor wherein reliability is increased and noise is reduced by developing a sufficient centrifugal action with rotation of a driveshaft and ensuring a high oiling characteristic even at a low speed rotation. <P>SOLUTION: An oiling passage 20 defined from a lower end of a main shaft portion 7 to an upper end of a crankshaft portion 9 in the driveshaft 6 to pump lubricating oil in an oil sump part 19 via a centrifugal action with rotation of the driveshaft and supply it to each sliding portion has an oil groove 33 for leading the lubricating oil pumped from the oil sump part to the circumference of the main shaft portion, a main shaft oil hole 34 communicating with an upper end of the oil groove to lead the lubricating oil toward the center axis of the main shaft portion, and an outlet hole 35 communicating with a tip end of the main shaft oil hole to emit the lubricating oil from an opening (a) opening on an end face of the crankshaft portion. A radius d from the center axis L of the main shaft portion to the outlet hole opening is set larger (d>D) than a distance (groove bottom radius) D from the center axis of the main shaft portion to the connection between the main shaft oil hole and the oil groove. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating hermetic electric compressor mounted in, for example, a refrigerator-freezer.
In particular, it relates to the improvement of the oil supply structure.

[0002]

2. Description of the Related Art For example, in a refrigerator and a refrigerator, a reciprocating hermetic electric compressor is often used as a compressor constituting a refrigeration cycle. This kind of compressor has
An electric compressor body in which a lower electric motor unit and an upper compression mechanism unit are integrated via a drive shaft is housed. Further, an oil reservoir for collecting the lubricating oil is formed at the bottom of the closed case, and the lower end of the drive shaft is immersed in the lubricating oil in the oil reservoir. The drive shaft is provided with an oil supply passage, and the centrifugal force generated by this rotation is used to suck up the lubricating oil in the oil sump and supply it to the sliding parts such as the compressor part. .

Japanese Utility Model Laid-Open No. 62-90987 discloses a technique relating to an oil supply structure in a compressor of this type. FIGS. 6A and 6B are cross-sectional views of the essential parts of a conventional compressor. A drive shaft 52 composed of a main shaft portion 50 and a crank shaft portion 51 has an oil groove 53 spirally formed on the peripheral surface of the main shaft portion 50.
Is provided. A spindle oil hole 54, which communicates with the upper end of the oil groove 53 and guides the lubricating oil toward the central axis L of the spindle portion 50, is provided. The crankshaft portion 51 is communicated with the tip of the spindle oil hole 54.
A lead-out hole 55 is provided across the side.

In FIG. 6 (A), the lead-out hole 55 is formed to be slightly inclined, and its upper end has a diameter slightly smaller than the diameter of the crankshaft portion 51, and a recess 56 which opens to the upper end of the crankshaft portion 51. Open on the bottom. Also, the recess 5
A crank oil hole 57 is provided so as to penetrate the six peripheral surfaces and the peripheral surface of the crankshaft portion 51. In FIG. 6B, the lead-out hole 55 is provided in parallel with the central axis L of the main shaft portion 50, and opens at the upper end surface of the crank shaft portion 51 with its diameter unchanged. A crank oil hole 57, which connects the lead-out hole 55 and the peripheral surface of the crank shaft portion 51, is provided in a substantially middle portion of the lead-out hole 55.

In any structure, a spiral crank oil groove 58 that connects the crank oil hole 57 and the upper end of the crank shaft portion 51 is provided on the peripheral surface of the crank shaft portion 51. Refueling passages 60A, 6 configured in this way
0B, the lubricating oil is sucked up into the oil groove 53 by the action of the centrifugal force due to the rotation of the drive shaft 52, and the lubrication of the sliding portion between the peripheral surface of the main shaft portion 50 and the pivot support hole portion of the frame (not shown). Make up. Further, the lubricating oil is guided from the oil groove 53 to the main shaft oil hole 54, and is once guided in the central axis L direction of the main shaft portion 50. Then, the crankshaft portion 5 is guided from the tip of the main spindle oil hole 54 to the lead-out hole 55 and through the concave portion 56 or directly.
1. Sliding parts such as the upper end surface and the crankshaft peripheral surface are lubricated.

[0006]

The lift capacity of the lubricating oil in the oil supply passages 60A and 60B is determined by the centrifugal force acting on the lubricating oil and the viscous force of the lubricating oil itself. Has a greater effect.
Specifically, the centrifugal force is determined by the size of the outlet hole opening radius d from the central axis L of the main shaft portion 50 to the opening portion a of the outlet hole 55. In the above-mentioned configuration of the prior art, the opening a of the lead-out hole 55 is
Is opened at a position very close to the central axis L of the main shaft portion 50, and the lead-out hole opening radius d is the distance from the main shaft portion central axis L to the connecting portion of the main spindle oil hole 54 and the oil groove 53. (Groove bottom radius) D
It is set smaller (d <D).

Therefore, even if the drive shaft 52 rotates, a sufficient centrifugal force does not act on the opening a of the lead-out hole 55,
The amount of oil supplied to each sliding portion was insufficient, which was apt to occur, and particularly when the drive shaft 52 was operated at a low speed, almost no oil could be supplied. The present invention has been made in view of the above circumstances,
The purpose is to always provide sufficient centrifugal force action with the rotation of the drive shaft, to ensure high lubrication even at low speeds to improve reliability and reduce noise. The purpose of the present invention is to provide a reciprocating hermetic electric compressor that can achieve high set performance when mounted on a.

[0008]

To achieve the above object, the present invention is directed to an electric compressor body including a hermetically sealed case, and a lower electric motor unit and an upper compression mechanism unit housed in the hermetically sealed case. And a drive shaft in which a main shaft part fitted into the electric motor part of the electric compressor main body and a crank shaft part fitted into the compression mechanism part are integrally connected, and a main shaft part lower end of the drive shaft formed in the inner bottom part of the sealed case. The lubricating oil to be immersed in the oil, and from the lower end of the main shaft part of the drive shaft to the upper end of the crank shaft part. An oil groove for guiding the lubricating oil sucked from the oil sump to the peripheral surface of the main shaft portion, and the lubricating oil passage communicating with the upper end of the oil groove for supplying the lubricating oil to the central axis of the main shaft portion. Main shaft oil hole that is a horizontal hole that leads in the direction, And a lead-out hole communicating with the main-shaft oil hole for discharging lubricating oil from an opening opening on the end face of the crankshaft portion, and the radius d from the central axis of the main-shaft portion to the lead-out hole opening is equal to the central axis of the main-shaft portion. Is set to be larger (d> D) than the distance (groove bottom radius) D from the spindle oil hole to the connecting portion of the oil groove.

Further, the hole diameter of the lead-out hole or the equivalent diameter of the cross section (= 4 × cross-sectional area / perimeter of the cross-section) is set to be smaller than the hole diameter of the oil supply passage upstream of the lead-out hole or the equivalent diameter of the cross section. To be done. Further, the lead-out hole is provided obliquely with respect to the central axis of the main shaft portion. In order to satisfy the above-mentioned object, the present invention provides an electric compressor main body including a hermetically sealed case, a lower side electric motor unit and an upper side compression mechanism unit housed in the hermetically sealed case, and an electric motor of the electric compressor main body. Drive shaft in which a main shaft part to be fitted to a shaft part and a crank shaft part to be fitted to the compression mechanism part are integrally connected, and an oil reservoir for lubricating oil formed in the bottom of the inner case of the main shaft part of the drive shaft And a lubrication passage that is provided from the lower end of the main shaft part of the drive shaft to the upper end of the crank shaft part and that is pumped up by the centrifugal force accompanying the rotation of the drive shaft to supply it to each sliding part. The oil supply passage is provided with an oil groove for guiding the lubricating oil sucked up from the oil sump to the peripheral surface of the main shaft portion, and a main shaft oil which is a lateral hole communicating with the upper end of the oil groove and for guiding the lubricating oil in the central axis direction of the main shaft portion. Hole and the spindle oil hole A lead-out hole, a recess which is communicated with the upper end of the lead-out hole and is provided on the upper end surface of the crankshaft portion and which is opened, and a plug member which is fitted into the bottom surface of the recess with a predetermined gap to close the recess, An opening provided in the plug member, and a radius d from the central axis of the main shaft portion to the plug member opening portion is a distance from the central axis of the main shaft portion to a connecting portion between the main spindle oil hole and the oil groove. It is set to be larger than (groove bottom radius) D (d> D), and the hole diameter of the plug member opening or the equivalent diameter of the cross section (= 4 x cross sectional area / peripheral length of cross section) is upstream from the opening. Is set to be smaller than the hole diameter of the oil supply passage or the equivalent diameter of the cross section.

Further, the opening provided in the plug member is a notch which opens to the outer peripheral surface of the plug member, and the notch opening is provided from the peripheral surface of the recess to the crank oil peripheral surface. Communicated with the hole. Further, the opening provided in the plug member is a hole penetrating the outer peripheral surface of the plug member while being spaced apart, and a crank oil hole penetrating from the peripheral surface of the concave portion to the peripheral surface of the crankshaft portion is formed on the lower side of the plug member. It is provided. Further, the ratio (d / D) of the radius d from the central axis of the main shaft portion to the opening portion and the distance (groove bottom radius) D from the central axis of the main shaft portion to the connecting portion between the main shaft oil hole and the oil groove. Is set to be 100 to 130%.

By adopting the means for solving the above problems, a sufficient centrifugal force action is always provided with the rotation of the drive shaft, and a high lubrication property is ensured even at a low speed rotation to improve the reliability. Noise can be reduced, and it can be installed in, for example, a refrigerator / freezer so that it can be operated continuously without repeating on / off even when the load is light, improving energy efficiency and reducing temperature fluctuations in the refrigerator. High set performance such as improved storage stability can be obtained.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a front view of a vertical cross section of a reciprocating hermetic electric compressor, which is a compressor that constitutes a refrigerating cycle of a refrigerator-freezer, for example. In the figure, 1 is a vertical type closed case, and a frame 2 is elastically supported in the closed case 1 via a spring (not shown). The compression mechanism section 3 is mounted on the upper side of the frame 2 and the electric motor section 4 is provided on the lower side. The compression mechanism section 3 and the electric motor section 4 constitute an electric compressor body 5.

The compression mechanism section 3 employs a so-called reciprocating compression mechanism. That is, the frame 2
A hole 2a for pivotal support is provided along the center of the drive shaft 6, and a part of the main shaft portion 7 constituting the drive shaft 6 is rotatably fitted therein. A flange portion 8 slidably mounted on the upper surface of the frame 2 is integrally provided at an upper end portion of the main shaft portion 7, and a central portion eccentric to a central axis of the main spindle portion 7 is provided at an upper portion of the flange portion 8. A crank shaft portion 9 having a shaft is continuously provided.

From this, when the main shaft portion 7 is rotationally driven, the flange portion 8 rotates in a sliding contact state with the upper surface of the frame 2, and the crank shaft portion 9 extends along the periphery of the central axis of the main shaft portion 7. It is designed to rotate eccentrically. Further, the compression mechanism section 3 is mounted on the upper surface of the frame 2 and includes a cylinder 10 whose axis is oriented horizontally. The inside of the cylinder 10 is a cylinder chamber 12 in which a piston 11 is reciprocally housed.

One end of a connecting rod 13 is connected to the piston 11 via a ball joint mechanism portion 14. The other end of the connecting rod 13 is provided with a large end portion 15 rotatably fitted to the crankshaft portion 9. As a result, the eccentric rotation of the crank shaft portion 9 allows the connecting rod 13 to perform a swinging motion with the ball joint mechanism portion 14 as a fulcrum, and the piston 11 reciprocates in the cylinder 10. .

On the other hand, the open end of the cylinder 10 is closed by a valve mechanism whose details are omitted, and the valve cover 16 is provided.
Covered with. Although not shown, the valve cover 16
Is provided with a partition portion that divides the interior into two parts, one space of which is a suction chamber and the other space of which is a discharge chamber. The valve mechanism is provided with a suction port and a valve plate having a discharge port,
Each suction port and each discharge port are opened and closed by a suction valve and a discharge valve. The suction port faces the suction chamber, and the discharge port faces the discharge chamber.

In contrast to the compression mechanism section 3 constructed as described above, the electric motor section 4 is connected to the frame 2 of the main shaft section 7.
A rotor 17 fitted to a portion projecting downward from the stator 17, and a stator 18 having an inner peripheral surface having a narrow gap with the peripheral surface of the rotor 17 and vertically fixed from the frame 2 by appropriate means. Become. Further, an oil reservoir 19 for collecting lubricating oil is formed at the bottom of the closed case 1, and the lubricating oil of the oil reservoir 19 is guided to the drive shaft 6 to each sliding portion such as the compression mechanism 3. An oil supply passage 20 described later is provided. A suction pipe 21 communicating with a refrigeration cycle device (evaporator) is connected to a side wall of the closed case 1, and an open end of the suction pipe 21 faces the closed case 1. Further, a discharge pipe 22 that is integrated with a discharge pipe (not shown) extending from the compression mechanism portion 3 and communicates with a refrigeration cycle device (condenser).
Penetrates the side wall of the closed case 1.

FIG. 2 is a sectional view of a part of the drive shaft 6 for explaining the oil supply passage 20. Hereinafter, the oil supply passage 20 will be described in detail with reference to FIGS. 1 and 2. The oil suction port body 30 provided integrally with the lower end portion of the main shaft portion 7 is immersed in the lubricating oil collected in the oil sump portion 19. The oil suction port body 30 is a tubular body having a small diameter at the lower end portion and a large diameter at the upper end portion and having a substantially horn-shaped cross section, and the upper end portion is fitted into the lower end of the main shaft portion 7.

From the lower end surface of the main shaft portion 7 to the substantially middle portion,
An eccentric oil hole 31 is provided so as to be eccentric with respect to the central axis L of the main shaft portion 7 and in parallel with the central axis L. An upper end portion of the eccentric oil hole 31 and the peripheral surface of the main shaft portion 7 are provided with an oil lateral hole 32. Communicated. The oil suction port body 30 does not necessarily have to be provided, and the lower end portion of the main shaft portion 7 is extended and directly immersed in the lubricating oil of the oil sump portion 19, and the lower end portion of the eccentric oil hole 31 is inserted into the oil suction port. You may substitute for the body.

A spiral oil groove 33 is provided on the peripheral surface of the main shaft portion 7 so as to communicate with the opening end of the peripheral surface of the main shaft portion 7 of the oil horizontal hole 32. The oil groove 33 is the upper end portion of the main shaft portion 7. The collar part 8
Is formed over the lower part of the. A spindle oil hole 34 formed of a lateral hole from the upper end of the oil groove 33 toward the central axis L of the spindle portion 7.
Is provided, and the oil groove 33 and the spindle oil hole 34 are communicated with each other. The lower end portion of the lead-out hole 35 is provided so as to communicate with the tip of the spindle oil hole 34.

The lead-out hole 35 penetrates the crankshaft portion 9 in a state of being inclined with respect to the central axis L of the main shaft portion 7,
On the upper end surface of the crank shaft portion 9, there is provided an opening a that opens at a position very close to the peripheral surface of the crank shaft portion 9. And
The radius from the central axis L of the main shaft portion 7 to the opening a of the lead-out hole 35 is defined as d, and the central axis L of the main shaft portion 7 to the main spindle oil hole 34.
It is characterized in that when the distance between the oil groove 33 and the oil groove 33 (hereinafter referred to as the groove bottom radius) is D, d is set to be larger than D (d> D).

Further, the hole diameter of the lead-out hole 35 or the equivalent diameter of the cross section (= 4 × cross-sectional area / peripheral length of the cross section) is defined as the hole diameter of the oil supply passage 20 upstream of the lead-out hole 35 or the equivalent diameter of the cross section. Another feature is that it is set smaller. The equivalent diameter is a representative length indicating how much the diameter of the flow passage is equivalent to a set of circular pipes from the point of flow, and when a fluid such as water flows, the equivalent diameter Since friction loss becomes a problem, it is often evaluated using De (equivalent diameter). A crank oil hole 36, which is a lateral hole that connects the lead-out hole 35 and the peripheral surface of the crank shaft portion 9, is provided at a substantially intermediate portion of the lead-out hole 35.
Further, a spiral crank oil groove 37 is provided on the peripheral surface of the crank shaft portion 9 from the crank oil hole 36 to the upper end surface of the crank shaft portion 9.

Next, the compression operation of the reciprocating hermetic electric compressor will be described. When the electric motor section 4 is energized to drive the drive shaft 6 to rotate, the crankshaft section 9 integrally rotates eccentrically. In response to this eccentric rotation, the piston 11 reciprocates in the cylinder chamber 12 via the connecting rod 13 and the ball joint mechanism portion 14.

The closed casing 1 is filled with a refrigerant gas, which has been vaporized by the evaporator and has been reduced in pressure, through the suction pipe 21. The refrigerant gas is guided to the suction chamber inside the valve cover 16, and is further sucked into the cylinder chamber 12 of the cylinder 10 with the movement (forward movement) of the piston 11. When the piston 11 moves (returns) in the opposite direction to compress the refrigerant gas and the piston 7 moves to the so-called top dead center position, the discharge valve is opened. Therefore, the cylinder chamber 12
The gas that has been compressed and increased in pressure is discharged into the discharge chamber of the valve cover 16.

This high-pressure gas is guided to the condenser from the discharge pipe 22 penetrating the closed case 1 through a discharge pipe in the case (not shown). Since the main shaft portion 7 is continuously rotating, the piston 11 moves back and the above refrigeration cycle is repeated. Next, the oil supply operation associated with the above-mentioned compression action will be described. When the drive shaft 6 rotates, the oil suction port body 30 provided at the lower end of the main shaft section 7 rotates integrally, and due to its shape, a centrifugal force acts to suck up the lubricating oil. Since the eccentric oil hole 31 provided in the main shaft portion 7 also eccentrically rotates, centrifugal force acts, and the lubricating oil sucked up by the oil suction port body 30 is further guided to the upper side.

Lubricating oil is guided from the upper end of the eccentric oil hole 31 to the oil groove 33 through the main shaft lateral hole 34, receives centrifugal force and conducts through the oil groove 33 by viscous force of itself, and the peripheral surface of the main shaft portion 7 And the sliding portion between the pivot hole 2a of the frame 2 is lubricated. Further, the lubricating oil is guided from the oil groove 33 to the main shaft oil hole 34. Since this spindle oil hole 34 is a horizontal hole,
The lubricating oil is once introduced in the direction of the central axis L of the main shaft portion 7,
Further, the oil is guided from the tip of the spindle oil hole 34 to the outlet hole 35.

Since the lead-out hole 35 is formed obliquely, the lubricating oil is efficiently sucked up and led out from the upper end surface of the crankshaft 9. Some lubricating oils have a lead-out hole 3
5 is guided to the crank oil groove 37 through the crank oil hole 36. The opening a of the lead-out hole 35 and the crank oil groove 37
Any lubricating oil introduced to the crankshaft 9 is connected to the large end 15, the connecting rod mechanism 14 and the cylinder 1.
Oil will be supplied to each sliding portion such as between 0 and the piston 11.

In the oil supply passage 20 as described above, in particular,
Since the spindle oil hole 34 is provided as a lateral hole, the lubricating oil must move from the circumferential surface of the spindle portion 9 in the direction of the central axis L in the direction opposite to the movement due to the centrifugal force action. this is,
The lubricating oil is introduced from the tip of the main shaft oil hole 34 to the end surface and the peripheral surface of the crankshaft portion 9 through the outlet hole 35, resulting in a loss of the oil supply characteristic. However, in this compressor, the opening portion a of the lead-out hole 35 is separated from the central axis L of the main shaft portion 7.
Up to the radius d up to the groove bottom radius D in the spindle oil hole 34
Is set to a larger value (d> D).

Therefore, even if the drive shaft 6 is rotated at a low speed, a large centrifugal force acting on the lead-out hole 35 can be secured,
A sufficient amount of lubricating oil can be guided to the crank oil groove 37 through the outlet hole 35 and the crank oil hole 36 by compensating for the loss in the main spindle oil hole 35, and oil can be supplied to each sliding portion in the periphery thereof. Is surely done. Further, the hole diameter of the lead-out hole 35 or the equivalent diameter of the cross-section (= 4 × cross-sectional area / perimeter of the cross-section) is set to be smaller than the hole diameter of the oil supply passage 20 upstream of the lead-out hole 35 or the equivalent diameter of the cross-section. This is also one of the features.

Under these conditions, the final centrifugal force acting on the lubricating oil due to the rotation of the drive shaft 6, that is, the centrifugal force acting in the lead-out hole 35 can be fully utilized. The lubricating oil is continuously drawn up along the outlet hole 35 and is surely sucked up. Even if there is resistance in the oil supply passage 20 on the upstream side of the outlet hole 35, the crankshaft 9 is sufficiently oiled. If the lead-out hole 35 is provided obliquely with respect to the central axis L of the main shaft portion 7 and is formed so that the diameter thereof widens upward, the centrifugal force can be gradually increased. The lubricating oil can be pumped to the opening a more reliably, and the crank oil hole 36 can be reliably fed to the crank oil groove 37.

FIG. 3A is a partial cross-sectional view of a drive shaft 6A having an oil supply passage structure of another embodiment. The shape and structure of the drive shaft 6A itself, to which the main shaft portion 7 and the crank shaft portion 9 are integrally connected via the collar portion 8, does not change. The oil supply passage 20A provided in the drive shaft 6A has a main shaft oil hole 34 from the suction port body 30 via an eccentric oil hole 31 and an oil groove 33.
The configuration up to here is the same as that described above.

The lead-out hole 35A communicating with the tip of the main spindle oil hole 34 is provided at a position extremely close to the central axis L of the main spindle portion 7 and in parallel with the central axis L of the main spindle portion 7. A recess 38 is provided so as to communicate with the upper end of the lead-out hole 35A. The concave portion 38 is opened on the upper end surface of the crankshaft portion 9 and is formed as a recess with a wall thickness that ensures the necessary minimum strength of the crankshaft portion 9. The plug member 4 is provided in the recess 38.
The plug member 40 closes the recess 38.

The position where the plug member 40 is fitted in the recess 38 is almost the bottom surface of the recess 38, but a space is formed to some extent between the plug member 40 and the bottom surface of the recess 38. The plug member 40 is a plate member having a predetermined thickness, and since the plug member 40 is fitted into the recess 38, the peripheral surface of the plug member 40 and the peripheral surface of the recess are closely fitted so that lubricating oil does not pass or penetrate. An opening b is provided at a position farthest from the central axis L of the main shaft of the plug member 40.

That is, although the position of the lead-out hole 35A opening on the bottom surface of the concave portion 38 is separated from the central axis L of the main shaft portion 7 by a slight distance, the opening portion b provided in the plug member 40.
Is most distant from the central axis L of the main shaft portion 7 of the plug member 40. The opening b provided in the plug member 40 corresponds to the opening a of the lead-out hole 35 described above with reference to FIGS. 1 and 2, and the opening b from the central axis L of the main shaft portion 7 is formed.
Is set to be larger (d> D) than the groove bottom radius D in the spindle oil hole 34.

Further, the hole diameter of the opening a of the plug member 40 or the equivalent diameter of the cross section may be set smaller than the hole diameter or the equivalent diameter of the cross section of the oil supply passage 20A upstream of the opening a. It is one of the features. As a result, the passage resistance in the lead-out hole 35A is reduced, and the plug member 4
The lubricating oil fills the space formed between 0 and the bottom of the recess 38. The final centrifugal force is applied to the effective portion, so that the lubricating oil can be sucked up continuously and reliably and a sufficient amount of oil can be supplied to each sliding portion.

The opening b provided in the plug member 40 is a notch opened to the outer peripheral surface of the plug member 40, as shown in FIG. 3 (C). As shown in FIG. 3 (A), the cutout opening b communicates with the peripheral wall of the concave portion 38 of the crankshaft portion 9 and the crank oil hole 36 penetrating the peripheral wall of the crankshaft portion 9. A part of the lubricating oil conducted through the notch opening b of the plug member 40 is partially recessed on the upper surface side of the plug member 40.
The remaining part is guided to the crank oil groove 37 through the crank oil hole 36. Therefore, a sufficient amount of lubricating oil is introduced to the upper surface of the crankshaft portion 9 and the crank oil groove 37 for lubrication.

FIG. 3B is a partial sectional view of a drive shaft 6A having an oil supply passage structure according to another embodiment. In this case as well, the plug member 40 having the notch opening b is used as the lead-out hole 3
There is no change in fitting into the recess 38 communicating with 5A. The difference from the one described above is that the plug member 4 is
0 is fitted to the upper side from the center of the crank oil hole 36 provided in the crankshaft 9.

Therefore, the distance between the bottom surface of the recess 38 and the lower surface of the plug member 40 can be secured to some extent, and the volume of the space between them becomes large, so that the amount of lubricating oil accommodated in the space is as shown in FIG. It will be larger than the composition. As a result, a larger amount of lubricating oil can be supplied to each sliding portion such as the crankshaft portion 9 and the oil supply characteristic is secured even when the drive shaft 6A is rotated at a lower speed.

FIG. 4 (A) is a partial sectional view of a drive shaft 6B having an oil supply passage structure of another embodiment, and FIG. 4 (B) is a plan view of a plug member 40a used here. The figure is shown. Oil supply passage 20B provided on the drive shaft 6B
At, a plug member 40a having an opening c described later is fitted into the recess 38 communicating with the lead-out hole 35A. In addition,
The plug member 40a is fitted above the crank oil hole 36 provided in the crankshaft 9.

An opening c provided in the plug member 40a
Is provided at a position where it does not interfere with the peripheral surface of the plug member 40a,
It is a hole penetrating in the plate thickness direction. With such a configuration, the distance between the bottom surface of the concave portion 38 and the lower surface of the plug member 40 can be secured to some extent, the volume of the space portion becomes large, and a sufficient amount of lubricating oil can be accommodated.

In addition, the opening c of the plug member 40a
Since it has a hole shape and is squeezed, the crank oil hole 36
Also, a sufficient amount of lubricating oil can be introduced into the crank oil groove 37. FIG. 5 shows a radius d from the central axis L of the main shaft portion 7 to the openings a, b, c in each of the embodiments described above.
FIG. 6 is a characteristic diagram showing an oil supply amount ratio with respect to a radial distance ratio which is a ratio (d / D) between the groove bottom radius D and the groove bottom radius D.

When the radial distance ratio is 100 to 110%, the oil supply amount ratio is slightly increased.
At 0%, the increasing tendency of the oil supply amount ratio becomes clear, and 120 to 1
At 30%, the refueling amount ratio increases remarkably. Therefore, it was found that the maximum lift of the lubricating oil was improved by 50% or more as compared with the conventional case (lubrication amount ratio: 100). Further, by adopting the configuration of the above-mentioned reciprocating type hermetic electric compressor as the compressor incorporated in the refrigeration cycle including the evaporator and the condenser, the minimum rotation speed could be reduced by 5% or more.

Although the ball joint method is adopted as the piston driving method in the compression mechanism section 3 described above, the present invention is not limited to this, and other driving methods such as the Scotch yoke method and the connecting rod method are used. The same effect can be obtained by using. Further, the above-described compression mechanism section 3 is described as a one-cylinder type, but a two-cylinder type having two cylinders can also obtain similar operational effects, and the types of refrigerant and lubricating oil are different. Even in the case, the same effect can be obtained.

[0044]

As described above, according to the present invention, high reliability at low speed rotation can be ensured, and when it is installed in, for example, a refrigerator / refrigerator, a reciprocating hermetically-sealed electric compression machine can obtain high set performance. Machine can be provided.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a reciprocating hermetic electric compressor showing an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of a drive shaft illustrating the configuration of the oil supply passage according to the embodiment.

FIG. 3 is a partial cross-sectional view of a drive shaft for explaining different oil supply passage configurations according to another embodiment, and a view for explaining an opening in a plug member.

FIG. 4 is a partial cross-sectional view of a drive shaft for explaining a configuration of an oil supply passage and a view for explaining an opening in a plug member according to still another embodiment.

FIG. 5 is a characteristic diagram of an oil supply amount ratio with respect to a radial distance ratio in the present invention.

FIG. 6 is a partial cross-sectional view of a drive shaft for explaining different conventional oil supply passage configurations.

[Explanation of symbols]

1 ... hermetically sealed case, 4 ... electric motor part, 3 ... Compression mechanism part, 7 ... Main shaft, 9 ... crankshaft part, 6, 6A, 6B ... Drive shaft, 19 ... Oil sump, 20, 20A, 20B ... Refueling passage, 33 ... Oil groove, 34 ... Spindle oil hole, 35, 35A ... Derivation hole, a, b, c ... opening, 38 ... recess, 40 ... Plug member, 36 ... Crank oil hole.

Claims (7)

[Claims] 1. An electric compressor main body, which comprises a hermetically sealed case, an electric motor section on the lower side and a compression mechanism section on the upper side, which is housed in the hermetically sealed case, and is fitted into the electric motor section of the electric compressor body. A drive shaft in which a main shaft portion and a crank shaft portion that is fitted into the compression mechanism portion are integrally provided, and an oil sump portion for lubricating oil, which is formed in the inner bottom of the sealed case and in which the lower end of the main shaft portion of the drive shaft is immersed An oil supply passage that is provided from the lower end of the main shaft part of the drive shaft to the upper end of the crank shaft part, and that pumps the lubricating oil in the oil sump part and supplies it to each sliding part by the action of the centrifugal force accompanying the rotation of the drive shaft. The oil supply passage is provided with an oil groove for guiding the lubricating oil sucked up from the oil sump to the peripheral surface of the main shaft portion, and a main hole which is a lateral hole communicating with the upper end of the oil groove and for guiding the lubricating oil in the central axis direction of the main shaft portion. Oil hole and communicate with this spindle oil hole The lubricating oil and a derivation holes that emit from an opening opened to the crankshaft end surface, the radius d from the central axis of the main shaft to the outlet hole opening
Is set to be larger (d> D) than the distance (groove bottom radius) D from the central axis of the main shaft portion to the connecting portion between the main spindle oil hole and the oil groove (d> D). Type electric compressor. 2. The diameter of the lead-out hole or the equivalent diameter of the cross section (= 4 × cross-sectional area / perimeter of the cross-section) is set smaller than the hole diameter of the oil supply passage upstream of the lead-out hole or the equivalent diameter of the cross section. The reciprocating hermetic electric compressor according to claim 1. 3. The reciprocating hermetic electric compressor according to claim 1, wherein the lead-out hole is provided obliquely with respect to the central axis of the main shaft portion. 4. An electric compressor main body comprising a hermetically sealed case, an electric motor section on the lower side and a compression mechanism section on the upper side, which is housed in the hermetically sealed case, and is fitted into the electric motor section of the electric compressor body. A drive shaft in which a main shaft portion and a crank shaft portion that is fitted into the compression mechanism portion are integrally provided, and an oil sump portion for lubricating oil, which is formed in the inner bottom of the sealed case and in which the lower end of the main shaft portion of the drive shaft is immersed An oil supply passage that is provided from the lower end of the main shaft part of the drive shaft to the upper end of the crank shaft part, and that pumps the lubricating oil in the oil sump part and supplies it to each sliding part by the action of the centrifugal force accompanying the rotation of the drive shaft. The oil supply passage is provided with an oil groove for guiding the lubricating oil sucked up from the oil sump to the peripheral surface of the main shaft portion, and a main hole which is a lateral hole communicating with the upper end of the oil groove and for guiding the lubricating oil in the central axis direction of the main shaft portion. Communicate with the oil hole and this spindle oil hole A lead-out hole provided, a recessed portion that is communicated with the upper end of the lead-out hole and is opened to the upper end surface of the crankshaft portion, and a plug member that is fitted into the bottom surface of the recessed portion with a predetermined gap to close the recessed portion. And a radius d from the central axis of the main shaft portion to the opening of the plug member.
Is set to be larger (d> D) than the distance (groove bottom radius) D from the central axis of the main shaft portion to the continuous portion of the main spindle oil hole and the oil groove, and the hole of the plug member opening. The diameter or the equivalent diameter of the cross section (= 4 x cross-sectional area / perimeter of the cross section) is set to be smaller than the hole diameter of the oil supply passage upstream of the opening or the equivalent diameter of the cross section. Hermetic electric compressor. 5. The opening provided in the plug member is a notch opening to the outer peripheral surface of the plug member, and the notch opening is provided so as to penetrate from the peripheral surface of the concave portion to the peripheral surface of the crankshaft portion. The reciprocating hermetic electric compressor according to claim 4, wherein the reciprocating hermetic compressor is communicated with the crank oil hole. 6. The opening provided in the plug member is a hole penetrating the peripheral surface of the plug member at a distance from the peripheral surface of the plug member. The reciprocating hermetic electric compressor according to claim 4, wherein a crank oil hole is provided therethrough. 7. A radius d from the central axis of the main shaft portion to the opening, and a distance (groove bottom radius) D from the central axis of the main shaft portion to the connecting portion between the main spindle oil hole and the oil groove. Ratio (d / D)
Is set so as to be 100 to 130%, The reciprocating hermetic electric compressor according to any one of claims 1 to 6.