JP3249256B2 - Oil pump for hermetic compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil pump incorporated in a hermetic compressor to supply lubricating oil to sliding portions of the compressor.

[0002]

2. Description of the Related Art In a hermetic compressor such as a scroll compressor or a rotary compressor, a compression mechanism and an electric motor are arranged vertically inside a sealed housing, and a rotating shaft of the electric motor is connected to the compression mechanism. The rotary shaft is rotated by the electric motor, and the compression mechanism is driven by the rotary shaft.

[0003] Generally, in these hermetic compressors, the lubricating oil incorporated in the lower end portion of the rotary shaft and stored in the inner bottom portion of the hermetic housing is sucked, and the sliding mechanism of the compression mechanism passes through an oil supply hole formed in the rotary shaft. An oil pump is provided for supplying oil to the moving part.

Conventionally, an oil pump mounted on this hermetic compressor has a configuration shown in FIGS. 5 and 6.

In FIG. 1, reference numeral 1 denotes a sealed housing. Reference numeral 2 denotes a cylinder arranged at the inner bottom of the sealed housing 1, which has a cylinder chamber 3 whose lower surface is open. The cylinder 2 is fixed to the closed housing 1 by a stay 4 formed integrally therewith. The lower opening of the cylinder chamber 3 is closed by a thrust plate 5 and a cover plate 6 attached to the cylinder 2.

Reference numeral 7 denotes a rotating shaft. The lower end of the rotating shaft 7 is inserted into the cylinder 2, and an eccentric shaft 8 is formed at the lower end located in the cylinder chamber 3. Reference numeral 9 denotes an annular rotor disposed inside the cylinder chamber 3, which is rotatably fitted to the outer peripheral portion of the eccentric shaft 8, and whose outer peripheral surface contacts the inner peripheral surface of the cylinder chamber 3 to form the cylinder chamber 3. It is restricted to a crescent shape.

A blade-shaped projection 10 extending in the diameter direction is integrally formed on the outer peripheral portion of the rotor 9, and the blade-shaped projection 10 is formed on the inner peripheral surface of the cylinder chamber 3 along a small diameter direction.
1 is slidably inserted into the first member. This projection 10 partitions the cylinder chamber 3 into an oil supply chamber 3a and an oil discharge chamber 3b,
The rotation of the rotor 9 is prevented. The outer periphery of the rotor 9 is circular except for the protrusion 10.

[0008] A suction hole 12 is formed in the cover plate 6 below the oil supply chamber 3 a of the cylinder chamber 3, and communicates with the inner bottom of the closed housing 1.
The thrust plate 5 is formed with a suction hole 12 and a suction port 13 communicating with the oil supply chamber 3a of the cylinder chamber 3.

A discharge hole 14 is formed in the cover plate 6, and a discharge port 15 communicating with the discharge hole 14 and the oil discharge chamber 3 b of the cylinder chamber 3 is formed in the thrust plate 5. Communication hole 1 communicating with oil supply hole 17
6 are formed respectively.

The oil supply hole 17 is formed inside the rotary shaft 4 from the lower end to the upper end along the axial direction. A lubricating oil OIL is stored in the inner bottom of the sealed housing 1.

In this oil pump, since the projections 10 are formed integrally with the rotor 9, it is possible to prevent damage to the rotor and to reduce the number of parts.

When the oil pump configured as described above is rotated together with the rotating shaft 7 rotated by the electric motor, the eccentric shaft 8 is eccentrically rotated in the direction of the arrow shown in the figure. The rotor 9 is pushed by the eccentric shaft 8 that rotates eccentrically, and revolves revolvingly while the outer peripheral surface is in sliding contact with the inner peripheral surface of the cylinder chamber 3 of the cylinder 2 in a line. As the rotor 9 rotates, the capacities of the oil supply chamber 3a and the oil discharge chamber 3b in the cylinder chamber 3 relatively increase and decrease and change.

As the volume of the oil supply chamber 3a increases, the lubricating oil OIL stored in the inner bottom of the closed housing 1 passes through the suction hole 12 of the cover plate 6 and the suction hole 13 of the thrust plate 5. To the oil supply chamber 3a of the cylinder chamber 3. Further, as the volume of the oil discharge chamber 3b of the cylinder chamber 3 decreases, the oil discharge chamber 3b
Is pressurized and discharged from the discharge port 15 of the thrust plate 5.

The discharged lubricating oil OIL is supplied to the discharge holes 14 of the cover plate 6 and the communication holes 16 of the thrust plate 5.
Through the oil supply hole 17 from the lower end of the rotating shaft 7, flows out from the upper end of the rotating shaft 7 through the oil supply hole 17, and is supplied to each sliding portion of the compression mechanism to perform lubrication. Thereafter, the lubricating oil OIL flows down inside the sealed housing 1 and accumulates again at the bottom.

Further, this oil pump is provided with a relief valve 19 for releasing the lubricating oil OIL inside the oil pump to the inner bottom of the closed housing 1 when the amount of oil supply becomes equal to or more than a predetermined amount. That is, the cover plate 6
Is formed with a relief hole 18 communicating with the discharge hole 14 and the inner bottom of the sealed housing 1. Through this relief hole 18, the lubricating oil OIL inside the oil pump is released to the inner bottom of the sealed housing 1. .

The relief valve 19 includes a cover plate 6
A circular valve body 20 disposed on the lower surface of the valve body to open and close the relief hole 18; and a circular valve body 20 disposed outside the cover plate 6 and having one end abutting against the valve body 20 to release the relief hole 18 from the valve body 20.
And a spring holder 22 disposed outside the cover plate 6 and receiving the other end of the compression coil spring 21 by inserting it into the inner peripheral side thereof. I have.

The spring holder 22 has an arm shape made of a metal material, and has a mounting hole 23 at one end and a receiving surface 22a for receiving the other end of the compression coil spring 21 at the other end.
And an inner insertion protrusion 22b to be inserted into the inner peripheral side of the compression coil spring 21.

One end of the spring holder 22 is mounted on the cover plate 6 through a mounting hole 23 through a bolt 24. The other end of the compression coil spring 21 is received by a receiving surface 22a at the other end. The compression coil spring 21 is inserted into the inner peripheral side of the compression coil spring 21 to hold the compression coil spring 21 so as not to shift.

The compression coil spring 21 is held by a spring holder 22 and presses the valve body 20. The compression coil spring 21 has a spring force corresponding to the pressure inside the oil pump when the oil supply amount reaches a predetermined amount.

The relief valve 19 constructed as described above
In the case, the oil pump is operated by the oil pump at a preset oil supply amount.
When L is supplied, the valve body 20 pressed by the compression coil spring 21 closes the relief hole 18. When the oil supply amount of the lubricating oil OIL supplied by the oil pump becomes a predetermined amount or more,
As the pressure of the lubricating oil OIL inside the oil pump increases, the lubricating oil OIL pushes the valve body 20 toward the outside of the cover plate 6 against the spring force of the compression coil spring 21, so that the relief hole 18 is opened. .

As a result, the lubricating oil O inside the oil pump is
The IL escapes through the escape hole 18 into the lubricating oil OIL stored in the inner bottom of the sealed housing 1. When the pressure inside the oil pump decreases due to the escape of the lubricating oil OIL,
The compression coil spring 21 pushes the valve element 20 again to release the release hole 18.
Close.

[0022]

However, the spring holder 22 used in the above-mentioned relief valve 19 is in the form of an arm, and has a mounting hole 23 formed at one end and a compression coil spring 21 at the other end. End receiving surface 22a
And a complicated shape in which the inner insertion protrusion 22b to be inserted into the inner peripheral side of the compression coil spring 21 is formed, so that it is difficult to form the plate material by pressing, and the metal block material is cut by cutting. It is cut and manufactured. In addition, even if a metal block material is cut out by cutting, the processing is difficult due to the complicated shape, and the manufacturing cost is high.

The present invention has been made in view of the above circumstances, and has as its object to provide an oil pump for a hermetic compressor having a relief valve which is inexpensive to manufacture.

[0024]

In order to achieve the above object, an oil pump for a hermetic compressor according to the present invention is incorporated in a lower end portion of a rotating shaft for driving a compression mechanism housed in a hermetic housing, The lubricating oil stored in the inner bottom of the hermetic housing is sucked into the pump casing, and the lubricating oil is discharged from the pump casing to slide the compression mechanism through an oil supply hole formed inside the rotary shaft. The lubricating oil inside the pump casing from an escape hole formed in the wall of the pump casing to the inner bottom of the closed housing when the amount of refueling becomes a predetermined amount or more. In an oil pump having a relief valve for relief, the relief valve is housed in a recess provided around the relief hole in the wall of the pump casing. A circular valve body for opening and closing the relief holes are arranged, and a coil spring having one end applies a force in a direction of closing the relief hole against the valve body in contact with the valve body,
A cap-shaped spring holder for receiving the other end of the coil spring by surrounding the outer periphery thereof, the spring holder being a fastening member for fastening the pump casing through a flange having mounting holes at both ends. The pump casing is fastened by the same fastening body.

[0025]

The spring holding member used in the relief valve mounted on the oil pump of the present invention is of a type in which the end of the coil spring is surrounded and held from the outer peripheral side. The spring holding body used in the conventional relief valve is of a type that holds the end of the coil spring from the inner peripheral side, and therefore has a complicated shape to stably hold the coil spring.

On the other hand, if the end portion of the coil spring is surrounded and held from the outer peripheral side, the coil spring can be stably held with a simple shape. That is, the shape of the portion that holds the coil spring can be a simple shape like a cap. This makes it possible to easily form the spring holder by pressing using a metal plate. In the present invention, by easily forming a spring holder having a simple shape by press working, the manufacturing cost is significantly reduced as compared with a case where a metal block material having a complex shape is cut out by cutting. . As a result, a relief valve can be obtained at a low manufacturing cost.

The relief valve has a simple structure of each component constituting the relief valve and a structure for combining the components, and the operation of the valve element and the coil spring is smooth and stable, so that the valve operates smoothly. be able to. In addition, the relief valve can be easily assembled by reliably positioning and holding the valve element and the coil spring during assembly.

Further, a special member for fixing the spring holder is specially prepared by fastening the spring holder to the pump casing with the same bolt as the bolt for fastening each component constituting the pump casing. The number of parts is reduced, and the configuration is simplified.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

First, a scroll compressor will be described as an example of a hermetic compressor having the oil pump of the present invention with reference to FIG.

In FIG. 1, the interior of the sealed housing 31 is partitioned by a discharge cover 32 into a high-pressure space 33 and a low-pressure space 34. A scroll-type compression mechanism C is provided in the upper part of the low-pressure space 34, and a motor M is provided in the lower part.
However, the oil pump P of the present invention is further provided at the bottom of the low-pressure space 34 (the bottom of the sealed housing 31), and these are the scroll type compression mechanism C, the electric motor M, and the oil pump P.
Are connected by a rotating shaft 35 provided on the electric motor M.

The electric motor M includes a stator 36 fixed to the sealed housing 31, a rotor 37 combined inside the stator 36, and a rotating shaft 3 fixedly inserted through the rotor 37.
5, and the rotating shaft 35 extends below and above the rotor 37, respectively.

The scroll type compression mechanism C has a fixed scroll 38 and an orbiting scroll 39.
8 is provided with an end plate 40 and a spiral wrap 41;
Is provided with a discharge port 42. The orbiting scroll 39 includes an end plate 43 and a spiral wrap 44, and the end plate 4
A bush 46 is rotatably fitted into a boss 45 provided on the lower surface of the bush 3 via a bearing 47.
An eccentric shaft 48 provided at the upper end of the rotating shaft 35 is slidably inserted into 6.

Fixed scroll 38 and orbiting scroll 39
The end plate 40 and the end plate 43 are eccentric by a predetermined distance, and a plurality of closed spaces 49 are formed in which the wrap 41 and the wrap 44 are combined with each other at an angle of 180 degrees. The orbiting scroll 39 is slidably supported by a casing 50 fixed inside the hermetic housing 31, and between the orbiting scroll 39 and the casing 50,
An anti-rotation mechanism 51 is provided to allow the orbiting scroll 39 to revolve or not, but to prevent rotation.

The outer periphery of the end plate 40 of the fixed scroll 38 is supported by a casing 50 so as to be lifted up freely, and cylindrical flanges 52 and 53 are provided on the upper surface of the end plate 40 of the fixed scroll 38.
Are arranged concentrically.

A back pressure chamber 55 is formed between the cylindrical flanges 52 and 53 by sealingly sliding a cylindrical flange 54 provided on the lower surface of the discharge cover 32. The back pressure chamber 55 communicates with a closed space 49 in the middle of gas compression through a hole 56 provided in the end plate 40. Here, the hole 56 is located at a point in contact with the inner peripheral side of the wrap 41, and a high-pressure chamber 57
Are formed, and a low-pressure chamber 58 is formed on the outer peripheral side.
A gas suction pipe 59 is provided in the low pressure space 34 of the sealed housing 31, and a gas discharge pipe 60 is provided in the high pressure space 35.

In such a structure, the rotation shaft 35 is rotated by the drive of the motor M, and this rotation is transmitted to the orbiting scroll 39 of the compression mechanism C via the eccentric shaft 48, the bush 46 and the boss 45. The orbiting scroll 39 makes a revolving orbiting motion on a circular orbit having a revolving orbital radius while being prevented from rotating by the rotation preventing mechanism 51.

Then, the gas enters the low-pressure space 34 of the closed housing 31 via the suction pipe 59, and is sucked into the closed section of the compression mechanism C via a path (not shown). And
The closed space 4 is formed by the orbital movement of the orbiting scroll 39.
As the volume of 9 decreases, the gas reaches the center while being compressed, enters the high-pressure space 33 from the discharge port 42 through the high-pressure chamber 57, and is discharged to the outside through the gas discharge pipe 60.

At this time, the fixed scroll 38 is pressed against the orbiting scroll 39 by the gas pressure in the high-pressure chamber 57 and the back-pressure chamber 55 to prevent the gas from leaking from the inside of the closed space 49. When the liquid is sucked into the closed space 49, the fixed scroll 38 floats and escapes the liquid, thereby preventing the compression mechanism from being damaged.

Next, an embodiment of the oil pump P to which the present invention is applied will be described with reference to FIGS. In the figure, reference numeral 71 denotes a cylinder arranged and fixed on the inner bottom of the sealed housing 31, which has a cylinder chamber 72 whose lower surface is open. The cylinder 71 is fixed to the closed housing 31 by a stay 73 formed integrally therewith. The lower opening of the cylinder chamber 72 is closed by a thrust plate 74 and a cover plate 75 which are an example of a closing member attached to the cylinder 71 by bolts 98. Here, a pump casing is constituted by the cylinder 71, the thrust plate 74, and the cover plate 75, and the components constituting the pump casing are fastened by bolts 98 serving as fastening bodies.

The lower end of the rotary shaft 35 is inserted into the cylinder 71, and an eccentric shaft 76 is formed at the lower end located in the cylinder chamber 72. Reference numeral 77 denotes an annular rotor disposed inside the cylinder chamber 72, which is rotatably fitted to the outer peripheral portion of the eccentric shaft 76, and whose outer peripheral surface contacts the inner peripheral surface of the cylinder chamber 72 to form the cylinder chamber 72. It is restricted to a crescent shape.

A diametrically extending blade-shaped projection 78 is integrally formed on the outer periphery of the rotor 77, and is slidable in a slot 79 formed on the inner peripheral surface of the cylinder chamber 72 along the diametric direction. Has been inserted. This projection 78
Divides the cylinder chamber 72 into an oil supply chamber 80 and an oil discharge chamber 81, and prevents rotation of the rotor 77.

A suction hole 82 is formed in the cover plate 75 below the oil supply chamber 80 of the cylinder chamber 72, and communicates with the inner bottom of the closed housing 31. The thrust plate 74 is formed with a suction hole 82 and a suction port 83 communicating with the oil supply chamber 80 of the cylinder chamber 72.

The cover plate 75 has discharge holes 84.
Are formed in the thrust plate 74. The discharge port 85 communicates with the discharge hole 84 and the oil discharge chamber 81 of the cylinder chamber 72.
And a communication hole 86 communicating with the discharge hole 84 and the oil supply hole 87 of the rotating shaft 35 are formed respectively. The oil supply hole 87 is formed in the rotation shaft 35 along the axial direction from the lower end to the upper end. A lubricating oil OIL is stored in the inner bottom of the sealed housing 31.

Further, the oil pump is provided with a relief valve 91 for releasing the lubricating oil OIL inside the oil pump to the inner bottom of the closed housing 1 when the amount of oil supply becomes equal to or more than a predetermined amount. That is, the cover plate 7
5 is formed with a relief hole 88 communicating with the discharge hole 84 and the inner bottom of the sealed housing 71, and through this relief hole 88, the lubricating oil OIL inside the oil pump is released to the inner bottom of the sealed housing 1. I have. In addition, as shown in FIG. 2, a concave portion surrounding the open end of the escape hole 88 opened on the lower surface of the cover plate 75 is formed.

The relief valve 91 is provided on the cover plate 7.
5, a circular valve element 92 that opens and closes a relief hole 88 that is disposed on the lower surface of the valve body 5 and a relief hole that is disposed outside the cover plate 75 and has one end abutting on the valve element 92. Compression coil spring 93 for applying a force in the direction to close 88
And a spring holder 94 that is arranged outside the cover plate 75 and receives the other end of the compression coil spring 93 from its outer peripheral side. As shown in FIG. 2, the valve body 92 having a circular shape is housed and arranged in a concave portion provided around the escape hole 88.

The spring holder 94 is formed by pressing a strip-shaped metal plate. A spring cap 95 having a circular cap shape is formed upright at the center, and mounting holes are formed at both ends. 96 are formed respectively. That is, as shown in FIG. 2, the spring holding body 94 made of a strip-shaped metal plate is
It has a cap shape that receives the other end of the compression coil spring 93 by surrounding it from the outer peripheral side, and has a flange portion extending outward from both sides of the cap-shaped portion (spring holding portion 95). Mounting holes 96 are formed at both ends. Further, the spring holding portion 95 has a receiving surface portion abutting on the other end surface of the compression coil spring 93 and an enclosing portion surrounding the outer peripheral side of the other end of the compression coil spring 93. Also, the spring holding part 95
A pair of escape ports 97 are formed at opposing positions in the enclosing portion.

The spring holder 94 is arranged on the lower surface of the cover plate 75, and is attached to the cover plate 75 through bolts 98 in the attachment holes 96 at both ends. The spring holding portion 95 of the spring holding body 94 is put on the other end of the compression coil spring 93, receives the end of the compression coil spring 93, and surrounds the outer peripheral side of the compression coil spring 21. That is, the cap-shaped spring holder 94 is provided with mounting holes 96 at both ends.
Bolt 98 which is the same as the bolt 98 for fastening each component constituting the pump casing through a collar portion having
To the pump casing.

The compression coil spring 93 is held by the spring holding portion 95 so as not to be displaced, and presses the valve body 92.
The compression coil spring 93 has a spring force corresponding to the pressure inside the oil pump when the oil supply amount reaches a predetermined amount.

According to such a structure for mounting the spring holder 94, the spring holder 94 can be mounted by fastening to the pump casing with the same bolts for fastening the respective components constituting the pump casing. The number of parts is reduced without specially preparing a dedicated member, and the configuration is simplified. In addition, there is no need to provide a dedicated portion for mounting the spring holder, and the configuration can be simplified in this regard. it can.

In the oil pump configured as described above, the eccentric shaft 35 is eccentrically rotated in the direction of the arrow shown in the figure together with the rotating shaft 35 rotated by the electric motor M. The rotor 77 is pushed by the eccentric shaft 76 which rotates eccentrically, and revolves orbit while the outer peripheral surface slides on the inner peripheral surface of the cylinder chamber 72 of the cylinder 71 in one line. With the rotation of the rotor 77, the respective volumes of the oil supply chamber 80 and the oil discharge chamber 81 in the cylinder chamber 72 increase and decrease relatively and change.

As the capacity of the oil supply chamber 80 increases, the lubricating oil OIL stored in the inner bottom of the closed housing 31 passes through the suction hole 82 of the cover plate 75 and the discharge port 85 of the thrust plate 74. And is sequentially sucked into the oil supply chamber 80 of the cylinder chamber 72. Further, as the volume of the oil discharge chamber 81 of the cylinder chamber 72 decreases, the lubricating oil OIL in the oil discharge chamber 81 is pressurized and discharged from the discharge port 85 of the thrust plate 74.

The discharged lubricating oil OIL is sent from the lower end of the rotary shaft 35 to the oil supply hole 87 through the discharge hole 84 of the cover plate 75 and the communication hole 86 of the thrust plate 74, and passes through the oil supply hole 87 to the rotary shaft 35. It flows out from the upper end and is supplied to each sliding portion in the compression mechanism C to perform lubrication.
Thereafter, the lubricating oil OIL flows down inside the sealed housing 31 and collects again at the bottom.

When the oil pump is supplying the lubricating oil OIL at a preset oil supply amount, the relief valve 91 closes the relief hole 88 by the valve body 92 pressed by the compression coil spring 93. . Lubricating oil O supplied by oil pump P
When the oil supply amount of IL becomes equal to or more than a predetermined amount, the lubricating oil OIL turns the valve body 92 to the outside of the cover plate 75 against the spring force of the compression coil spring 93 due to the increase of the lubricating oil OIL inside the oil pump P. As a result, the escape hole 88 is opened.

As a result, the lubricating oil OIL inside the oil pump P passes through the escape hole 88 and enters the inside of the spring holding portion 95 of the spring holding body 94, and further the escape port 9 of the spring holding portion 95.
7 flows into the lubricating oil OIL stored in the inner bottom of the sealed housing 71. When the lubricating oil OIL escapes and the pressure inside the oil pump P decreases, the compression coil spring 93 pushes the valve body 92 again to close the escape hole 88.

The spring holder 94 used for the relief valve 91 provided in the oil pump according to the present invention has a coil spring 9.
3 is a method in which the end portion is surrounded and held from the outer peripheral side. The spring holding body used in the conventional relief valve is of a type that holds the end of the coil spring from the inner peripheral side, and therefore has a complicated shape to stably hold the coil spring.

On the other hand, if the spring holder 94 is of a type that holds the end of the compression coil spring 93 from the outer peripheral side, the compression coil spring 93 can be stably held with a simple shape. That is, the shape of the portion holding the compression coil spring 93 can be a simple cap-shaped shape.

Thus, according to the present invention, the spring holder 94 can be easily formed by pressing using a metal plate. By easily forming the spring holder 94 having a simple shape by press working, the manufacturing cost is significantly increased as compared with a case where a spring holder having a complicated shape is manufactured by cutting a metal block material by cutting. Reduce. As a result, the relief valve 91 can be obtained at a low manufacturing cost.

The relief valve 91 used for adjusting the oil supply amount used in the oil pump P uses a spring having a relatively small spring force against the pressure of the lubricating oil OIL flowing in the oil pump P. Therefore, the spring holder 94 used for the relief valve 91 may have a relatively small strength to withstand the spring force of the spring, and therefore, the spring holder 91 formed of a metal plate can be used. .

The relief valve 91 has a circular valve body 92 housed and arranged in a recess provided around the escape hole 88 in the wall of the pump casing to open and close the escape hole. Spring 93 that abuts against the valve body 92 and applies a force to the valve body 92 in a direction to close the escape hole.
And a bolt 98 which is the same fastening body as a fastening body for fastening the pump casing through a collar portion which receives the other end of the coil spring 93 by surrounding the outer periphery thereof and has a mounting hole 96 at both ends. And the spring holding body 94 fastened to the pump casing by the combination of the valve body 92 and the coil spring 9 constituting the relief valve.
The structure of each part of the spring 3 and the spring holding body 94 and the structure combining these parts are simple, respectively, and the operation of the valve body 92 and the coil spring 93 is smooth and stable, so that the smooth relief valve operation is performed. Can be.

In this relief valve 91, a circular valve element 93 is accommodated and arranged in a concave portion provided around a relief hole 88, and a coil spring 93 is formed in a cap-shaped spring holding member 9.
4 and a spring holder 94 is attached to a pump casing through a bolt 98 serving as a fastening member in an attachment hole 96 formed at each end of the flange portion, so that the valve body 92 and the coil spring 93 are respectively located at predetermined positions during assembly. It is possible to easily assemble it by reliably positioning and holding it.

The present invention is not limited to the above-described embodiment, but can be implemented with various modifications. For example, the compression mechanism is not limited to the scroll type, but may be a rotary type.

[0063]

As described above, according to the oil pump of the hermetic compressor of the present invention, the spring holder provided on the relief valve is of the type that surrounds and holds the end of the coil spring from the outer peripheral side. The coil spring can be stably held in a simple shape, and the spring holder can be easily formed by pressing using a metal plate. Therefore, the relief valve can be manufactured at a low manufacturing cost.

The relief valve has a circular valve body which is housed and arranged in a recess provided around the relief hole in the wall of the pump casing and opens and closes the relief hole. A coil spring for applying a force to the valve body in a direction to close the escape hole, a pump having a cap shape surrounding and receiving the other end of the coil spring on its outer peripheral side and having mounting holes at both ends. Since the combination of the fastening body for fastening the casing and the spring holding body fastened to the pump casing by the same fastening body,
The configuration of each part constituting the relief valve and the configuration combining each part are simple, and the operation of the valve element and the coil spring is smooth and stable, so that the smooth relief valve operation can be performed.

In this relief valve, a circular valve body is housed and arranged in a recess provided around a relief hole, a coil spring is held by a cap-shaped spring holding body, and the holding body is further provided with a flange portion. By mounting the valve body and the coil spring to the pump casing through bolts, which are fastening bodies, in the mounting holes formed at both ends, the valve body and the coil spring can be reliably positioned and held at the time of assembling, and can be easily assembled.

Further, a special member for fixing the spring holder is specially prepared by fastening the spring holder to the pump casing with the same bolt as the bolt for fastening each component constituting the pump casing. The number of parts is reduced and the configuration is simplified,
Also, there is no need to provide a dedicated portion for attaching the spring holder, and the configuration can be simplified in this respect as well.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a scroll compressor equipped with an oil pump according to one embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a portion of an oil pump in FIG.

FIG. 3 is a sectional view taken along the line AA of FIG. 2;

FIG. 4 is a bottom view showing the oil pump in the embodiment.

FIG. 5 is a sectional view showing a conventional oil pump.

FIG. 6 is a sectional view taken along the line BB in FIG. 5;

[Explanation of symbols]

31: sealed housing, 35: rotary shaft, 71: cylinder, 72: cylinder chamber, 76: eccentric shaft, 77: rotor, 91: relief valve, 92: valve body, 93: coil spring,
94 ... Spring holder.

────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Masumi Sekita 1 Nagoya Laboratory, Iwazuka-cho, Nakamura-ku, Nagoya-shi, Aichi, Japan Nagoya Research Laboratories (56) References (58) Fields investigated (Int. Cl. ⁷ , DB name) F04C 29/02 311

Claims (1)

(57) [Claims] 1. A lubricating oil incorporated in a lower end of a rotary shaft for driving a compression mechanism housed in a hermetically sealed housing and stored in an inner bottom of the hermetically sealed housing is sucked into a pump casing. Oil is discharged from the pump casing and supplied to a sliding portion of the compression mechanism through an oil supply hole formed inside the rotary shaft, and when the oil supply amount is equal to or more than a predetermined amount, the pump casing is closed. An oil pump having a relief valve for releasing the lubricating oil inside from a relief hole formed in a wall portion of the pump casing to an inner bottom portion of the sealed housing, wherein the relief valve is provided in the wall portion of the pump casing. A circular valve body housed and disposed in a recess provided around the relief hole to open and close the relief hole, A coil spring for applying a force to the valve body in a direction to close the relief hole, and a cap-shaped spring holder that surrounds and receives the other end of the coil spring on its outer peripheral side; An oil pump for a hermetic compressor, wherein the oil pump is fastened to the pump casing by the same fastener as the fastener for fastening the pump casing through a flange having a mounting hole.