JPH0828465A - Scroll compressor - Google Patents

Abstract

PURPOSE:To increase the degree of freedom of the forming position of an oil returning passage by preventing return oil from a high pressure chamber to a low pressure chamber from being mixed to intake gas, preventing back flow of gas from the high pressure chamber to the low pressure chamber from being increased, and improving assemblage through a process of enhancing stiffness of the oil returning passage. CONSTITUTION:A compression element CF is provided in a casing 1, and a high pressure chamber 41 to which a discharging port and the outside discharging pipe of the compression element CF are opened is provided on one side of this compression element CF, and a low pressure chamber 42 to which an intake pipe is opened is formed on the other side. An oil returning passage 6 for recovering oil accumulating in the high pressure chamber 41 into the low pressure chamber 42 is provided between the high pressure chamber 41 and the low pressure chamber 42. The oil returning passage 6 is formed by a long guide pipe 1 wherein a small diameter passage 71 opening to the high pressure chamber 41 and a large diameter passage 72 opening to the low pressure chamber 42, and larger than the small diameter passage 71 are continuously formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil return structure for returning oil from a high pressure chamber to a low pressure chamber in a scroll type compressor having a high pressure chamber and a low pressure chamber.

[0002]

2. Description of the Related Art Generally, a scroll type compressor has a casing having a compression element having a first scroll and a second scroll, as disclosed in, for example, Japanese Utility Model Laid-Open No. 31392/1990. A low-pressure dome type scroll type in which a high-pressure chamber in which a discharge port of the compression element and an external discharge pipe are opened is formed on one side of the element, and a low-pressure chamber in which a motor is arranged is formed on the other side of the element. Compressors are known.

As shown in FIG. 6, the scroll compressor of the low-pressure dome type in which the high-pressure chamber is partitioned and formed in the casing as described above, the first scroll B is located in the upper part of the casing A.
And a second scroll C, a compression element CF is provided below the motor M, and a suction pipe D is opened between the compression element CF and the motor M to allow the suction into the casing A. A low pressure chamber E is formed in the casing A on the lower side of the compression element CF by flowing the suction gas from the pipe D.

The first scroll B of the compression element CF is fixed to the casing A through a frame F, and the second scroll C is interlocked with a drive shaft G extending from the motor M to prevent rotation. The mechanism H drives the first scroll B to revolve.

Further, the end plate B1 of the first scroll B is provided.
By the compression element CF in the casing A
The discharge port K of the compression element CF is opened on the side opposite to the motor side of
In addition, the high pressure chamber N where the external discharge pipe L is opened is connected to the low pressure chamber E.
It is divided and formed.

The gas discharged into the high-pressure chamber N usually contains oil, and the oil is contained in the high-pressure chamber N.
In the high pressure chamber N by this separation.
In order to return the oil accumulated in the low pressure chamber E to the bottom oil sump (not shown) of the low pressure chamber E, an oil return capillary tube P for communicating the high pressure chamber N with the low pressure chamber E is provided in the casing A. It is arranged.

The capillary tube P is inserted into a tube guide hole Q penetrating the frame F and the outer peripheral portion of the end plate B1 of the first scroll B for partitioning the high pressure chamber N and the low pressure chamber E. The end of the capillary tube P on the high pressure chamber side is fixed to the end plate B1 of the first scroll B via the bush R, and the end of the low pressure side is opened in the tube guide hole Q. In order to prevent a large amount of high-pressure gas in the high-pressure chamber N from flowing back into the low-pressure chamber E when oil is collected from the high-pressure chamber N to the low-pressure chamber E, the tube diameter of the tube is made extremely small. There is.

[0008]

However, since the capillary tube P is open in the tube guide hole Q, the oil flowing out from the capillary tube P is opened in the lower surface of the frame F. It is to be returned from Q to the low pressure chamber E.

Therefore, the opening of the tube guide hole Q to the low-pressure chamber N is located near the opening of the suction pipe D and near the suction port of the compression element CF, and the capillary. The oil returned from the tube P to the oil reservoir is mixed again with the suction gas flowing from the suction pipe D and is sucked into the compression element CF, so that the oil cannot be sufficiently recovered and the problem of oil rising still occurs. Was there.

Therefore, for example, Japanese Patent Laid-Open No. 4-124486.
As described in the publication, the length of the capillary tube P is lengthened so that the position of the low-pressure chamber side opening of the capillary tube P is apart from the suction port of the compression element CF and the opening of the suction pipe D. It has been proposed that the opening be made.

As shown in FIG. 7, the capillary tube P is inserted into a tube guide hole Q penetrating the first scroll B and the frame F, and one end thereof is located above the first scroll B. , A partition S for partitioning and forming the inside of the casing A into the high-pressure chamber N and the low-pressure chamber E is opened to the high-pressure chamber N, and the other end of the stator M1 of the motor M in the low-pressure chamber E is opened. The opening is made near the core cut portion M2.

However, since the length of the capillary tube P is long, the compression element CF is
Although it is possible to prevent the oil from being sucked into the tube, if the tube inner diameter is made the same as the conventional one, the passage resistance increases as the length increases, and the oil return deteriorates. On the contrary, if the tube diameter is increased so that the same oil return amount as the conventional one can be secured in order to reduce the passage resistance, even if the oil return amount is the same, the reverse flow from the high pressure chamber N to the low pressure chamber E is different from the conventional one. There was a problem in that the amount of high-pressure gas returned was increased.

That is, in the graph showing the relationship between the length of the capillary tube and the oil flow rate and the gas leakage rate in FIG. 5, the oil return amount (oil flow rate in the tube) is shown by a solid line. Assuming that the inner diameter (a) of the capillary tube P that has been used is 0.7 mm, for example, 1000 cc
The tube length is 2 in order to secure the oil return amount of / min.
Although it is set to 0 mm, when the length of the capillary tube P is increased to, for example, about 55 mm, the tube inner diameter (b) is increased to 0.8 mm in order to secure the same oil return amount as in the conventional case. There is a need.

At this time, in the graph of FIG. 5, the flow rate of gas from the high pressure chamber N to the low pressure chamber E (gas leak amount of the tube) is shown by a dotted line. Flow rate is 10 kg / h, the gas flow rate is 12 kg / h at the tube inner diameter (b) when the tube length is increased, and the amount of oil returned is the same as before, but at the same high pressure. The amount of high-pressure gas that flows back from the chamber N to the low-pressure chamber E increases.

Further, the capillary tube P is
Since the diameter is extremely small and it is formed from a copper pipe, its rigidity is low and it is easily bent. Therefore, the longer it is formed, the worse the assembling property to the tube guide hole Q or the like is problematic.

Further, since the capillary tube P has low rigidity, the tube guide hole Q is formed to protect the capillary tube P in order to prevent the capillary tube P from being deformed by the gas flow flowing from the suction pipe D. The part that is not protected by the guide hole Q is
The tube guide hole Q may be deformed by the gas flow, and when the tube guide hole Q is formed in the first scroll B and the frame F, the position thereof is limited. Therefore, the position of the capillary tube P is limited and the degree of freedom is limited. Therefore, when the scroll type compressor is used horizontally, there is a problem that it is difficult to apply due to the positional relationship with the bottom oil sump.

The present invention has been made in view of the above problems, and an object of the present invention is to prevent the return oil from the high pressure chamber to the low pressure chamber from being mixed into the suction gas, and at the same time to prevent the gas from the high pressure chamber to the low pressure chamber. It is an object of the present invention to provide a scroll compressor that can prevent an increase in backflow, enhance the rigidity of the oil return passage to improve the assemblability, and increase the degree of freedom in the formation position of the oil return passage.

[0018]

In order to solve the above problems, the invention according to claim 1 is such that a casing 1 is internally provided with a compression element CF having first and second scrolls 2 and 3, and this compression element CF is provided. The discharge port 22 of the compression element CF is provided on one side of the
And a high pressure chamber 41 in which the external discharge pipe 13 is opened, and a low pressure chamber 42 in which the suction pipe 14 is opened on the other side, and oil accumulated in the high pressure chamber 41 between the high pressure chamber 41 and the low pressure chamber 42. In the scroll compressor provided with the oil return passage 6 for collecting the oil in the low pressure chamber 42, a small diameter passage 71 opening to the high pressure chamber 41 and a large diameter passage opening to the low pressure chamber 42 and larger than the small diameter passage 71. The oil return passage 6 is formed by the long guide pipe 7 which is continuous with the diameter passage 72.

According to the second aspect of the present invention, the capillary tube P is inserted into the small-diameter passage 71 of the guide pipe 7, the one end side of the capillary tube P is held in the small-diameter passage 71, and the capillary tube P is held. The other end is opened into the large diameter passage 72.

[0020]

According to the first aspect of the invention, the small-diameter passage 71 allows the amount of oil returned from the high-pressure chamber 41 to the low-pressure chamber 42 to be the same as the conventional amount, and the backflow of the high-pressure gas refrigerant is also minimized. While being suppressed, the large-diameter passage 72 allows the return oil together with the suction gas from the suction pipe 14 to return to the compression element CF.
It is possible to prevent the oil from being sucked into the oil reservoir from the high pressure chamber 41 without using a capillary tube.

Further, since the oil return passage 6 is formed from the guide pipe 7 having a larger outer diameter than the conventional capillary tube having a smaller outer diameter, the rigidity thereof can be increased and, as a result, Since it is possible to prevent deformation at the time of assembling into the guide hole formed for inserting the guide pipe 7, the assembling property can be improved.

Since the guide pipe 7 has a high rigidity, it is not always necessary to insert the guide pipe 7 into a long guide hole for protecting the guide pipe 7 from the gas flow, and the end portion of the guide pipe 7 on the high pressure chamber side is not required. Just to support
Since the other portion can be exposed in the low pressure chamber 42, the formation position of the oil return passage 6 is not limited, and as a result, the degree of freedom of the formation position of the oil return passage 6 is expanded. When the scroll type compressor is used in the horizontal type, it is possible to form it according to the oil sump and it is easy to apply.

According to the second aspect of the present invention, the amount of oil returned from the high pressure chamber 41 to the low pressure chamber 42 can be made equal to the conventional amount by the capillary tube P, and the back flow of the high pressure gas refrigerant can be minimized. While being suppressed, it is possible to prevent the return oil from being sucked into the compression element CF together with the suction gas from the suction pipe 14 by the guide pipe 7, so that the high pressure chamber is used while using the capillary tube P having a short length. Oil can be reliably returned from 41 to the oil reservoir.

Further, since the capillary tube P can be held by the guide pipe 7 and the whole can be protected by the guide pipe 7, as a result, the guide pipe 7 having the capillary tube P and high rigidity can be provided. Since the assembling work can be performed only by assembling the guide tube into the guide hole or the like, the capillary tube P can be prevented from being deformed at the time of assembling and the assembling property can be improved.

Further, since the guide pipe 7 may have a short length for holding the small-diameter passage 71 to hold the capillary tube P, the small-diameter passage 71 becomes easier to process as its length becomes shorter. The processing of the guide pipe 7 can be easily performed.

Further, since the capillary tube P can be projected from the guide pipe 7 on the high pressure chamber 41 side, the projecting height of the capillary tube P is particularly high when it is applied to a vertical scroll compressor. Since dust mixed with oil or the like can be collected, it is possible to prevent dust from entering the capillary tube P.
It is possible to prevent clogging of the capillary tube P.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. In the scroll compressor of the first embodiment, a compression element CF is installed inside the closed casing 1 having an oil sump 10 at the bottom, and a motor M is installed inside the casing 1 below the compression element CF. The first scroll 2 serves as a fixed scroll, and the second scroll 3 serves as a movable scroll. The scrolls 2 and 3 are arranged vertically opposite to each other via a frame 11, and the second scroll 3 is connected to the motor. A partition body 5 is disposed inside the casing 1 on the upper side of the first scroll 2 while being interlocked with the drive shaft 12 of M, and by the partition body 5, the partition body 5 is disposed on the upper side of the partition body 5. The high pressure chamber 4 in which the discharge port 22 formed in the first scroll 2 is opened and the external discharge pipe 13 for discharging the discharged refrigerant to the outside of the casing is opened.
1, the suction pipe 14 is opened on the lower side of the partition body 5, and the low-pressure chamber 42 in which the motor M is disposed is defined.

Therefore, the rotation of the drive shaft 12 accompanying the drive of the motor M causes the second scroll 3 to move to the first
The scroll 2 is revolved and driven, and the low pressure gas sucked from the suction pipe 14 into the low pressure chamber 42 is sucked into the compression chamber formed by the scrolls 21 and 31 of the scrolls 2 and 3. The sucked gas is compressed, and the compressed gas is discharged from the discharge port 22 to the high pressure chamber 4
1 is discharged to the outside of the casing 1 from the external discharge pipe 13.

An oil return passage 6 is provided between the high pressure chamber 41 and the low pressure chamber 42 for recovering the oil accumulated in the high pressure chamber 41 to the low pressure chamber 42, and the oil separated in the high pressure chamber 41 is provided. Is collected in the oil sump 10 formed at the bottom of the low-pressure chamber 42, and the oil pump 15 provided at the lower end of the drive shaft 12 pumps up the oil to the oil supply passage 16 formed in the drive shaft 12 for each slide. I try to refuel the moving parts.

In the scroll compressor of the first embodiment, however, the oil return passage 6 is opened to the high pressure chamber 41 and the small diameter passage 71, and to the low pressure chamber 42. The large-diameter passage 72 having a diameter larger than 71 is formed by the long guide pipe 7 formed continuously.

Specifically, as shown in FIG. 1, the oil return passage 6 is composed of a long guide pipe 7 having a flange portion 73 having a large outer diameter at one end, and the guide pipe 7 is provided with the flange. A small diameter passage 71 opening to the high-pressure chamber 41 on the part formation side.
Is formed on the side opposite to the collar forming side, and the low pressure chamber 42 is opened.
The large-diameter passage 72, which is larger in diameter than the small-diameter passage 71, is formed continuously.

The small diameter passage 71 can collect a predetermined amount of oil accumulated in the high pressure chamber 41 into the low pressure chamber 42, and can reduce the backflow of the high pressure gas refrigerant from the high pressure chamber 41 to the low pressure chamber 42 as much as possible. The large-diameter passage 72 has a larger inner diameter than the small-diameter passage 71 in order to collect the oil flowing out from the small-diameter passage 71 into the oil reservoir 10 with less passage resistance, and The length of the motor M extends to near the coil end M3 formed on the stator M1.

Further, the guide pipe 7 is connected to the outer peripheral portion of the partition body 5 and the end plate 23 of the first scroll 2.
The padding portion 24 formed on the outer peripheral portion and the guide hole 8 axially penetrating the outer peripheral portion of the frame 11 are inserted,
A large diameter step portion 81 is formed in the guide hole 8 of the partition body 5, and the flange portion 73 of the guide pipe 7 is press-fitted into and supported by the step portion 81.

As described above, in the first embodiment, the small diameter passage 71 opening to the high pressure chamber 41 and the large diameter passage 72 opening to the low pressure chamber 42 and having a diameter larger than the small diameter passage 71 are connected continuously. Since the oil return passage 6 is formed by the long guide pipe 7 formed in the above, the amount of oil returned from the high pressure chamber 41 to the low pressure chamber 42 can be made equal to the conventional amount by the small diameter passage 71, and high pressure can be achieved. While the backflow of the gas refrigerant is also suppressed to a minimum, the return oil can be prevented from being sucked into the compression element CF together with the suction gas from the suction pipe 14 by the large diameter passage 72. The oil can be reliably returned to the oil sump 10 from the above.

Further, since the oil return passage 6 is formed from the guide pipe 7 having a larger outer diameter than the conventional capillary tube having a small outer diameter, the rigidity thereof can be increased, and as a result, Since the deformation at the time of assembling into the guide hole 8 can be prevented, the assembling property can be improved.

In the first embodiment, the guide pipe 7 is inserted into the guide hole 8. However, since the guide pipe 7 has high rigidity, the guide pipe 7 is
Need not be inserted into the guide hole 8 for protecting the gas flow from the gas flow, and the end portion of the guide pipe 7 on the high pressure chamber side is supported only by the guide hole 8 formed in the partition body 5, and The portion may be exposed in the low pressure chamber 42.

That is, the oil return passage 6 can be formed in the space formed between the end plate 23 of the first scroll 2 and the outer peripheral surface of the frame 11 and the inner peripheral surface of the casing 1, and the oil return passage 6 can be formed. The formation position of the return passage 6 is not limited, the degree of freedom of the formation position is widened, and when the scroll type compressor is used in a horizontal type, it is possible to form it according to the oil sump and it is easy to apply.

Next, a second embodiment will be described with reference to FIGS. 3 and 4. The second embodiment shows a horizontal scroll type compressor in which a compression element CF is arranged on one side in the longitudinal direction of the horizontally long casing 1 and a motor M is arranged on the other side. The basic structure is similar to that of the first embodiment, and the compression element CF is
Is composed of a first scroll 2 which is a fixed scroll and a second scroll 3 which is a movable scroll. The scrolls 2 and 3 are arranged to face each other via a frame 11, and the second scroll 3 is Drive shaft 1 of motor M
On the other hand, the partition body 5 is disposed inside the casing 1 on the side opposite to the motor of the first scroll 2,
The partition body 5 opens the discharge port 22 formed in the first scroll 2 on the side opposite to the compression element of the partition body 5 and discharges the discharge refrigerant to the outside of the casing 1.
The high pressure chamber 41 for opening the valve 3 is formed, and the suction pipe 14 is opened on the compression element side of the partition body 5 to define the low pressure chamber 42 in which the motor M is disposed.

An oil return passage 6 is provided between the high pressure chamber 41 and the low pressure chamber 42 for recovering the oil accumulated in the high pressure chamber 41 to the low pressure chamber 42, and the oil separated in the high pressure chamber 41 is provided. Is collected in the oil reservoir 10 formed at the bottom of the low-pressure chamber 42, and an oil pump (not shown) provided at the end of the drive shaft 12 on the side opposite to the compression element is used to form an oil supply passage 16 formed in the drive shaft 12. The oil is pumped up and oil is supplied to each sliding part.

Therefore, in the second embodiment, in the above scroll type compressor, the oil return passage 6 is opened to the high pressure chamber 41 and the small diameter passage 71, and to the low pressure chamber 42. A large-diameter passage 72 having a diameter larger than 71 is formed by a long guide pipe 7 formed continuously, and further, a capillary tube P is inserted into the small-diameter passage 71 in the guide pipe 7 and The small diameter passage 71 holds one end of the capillary tube P, and the other end of the capillary tube P is opened into the large diameter passage 72.

Specifically, as shown in FIG. 3, the oil return passage 6 is composed of a long guide pipe 7 having a collar portion 73 having a large outer diameter at one end and a capillary tube P. Reference numeral 7 denotes a small-diameter passage 71 that opens to the high-pressure chamber 41 on the flange portion forming side, and a large-diameter passage 72 that opens to the low-pressure chamber 42 on the anti-collar portion forming side and has a diameter larger than the small-diameter passage 71. The small-diameter passage 71 has a diameter such that the capillary tube P can be inserted and held, and the length thereof is shorter than that of the capillary tube P.
The large diameter passage 72 is formed so as to have a length sufficient to hold one end side of the capillary tube P.
Has an inner diameter larger than that of the small-diameter passage 71, and its length extends from the end of the small-diameter passage 71 to the vicinity of the motor-side end of the outer peripheral surface of the frame 11 to remove the oil returning from the capillary tube P. It is designed to flow out with little passage resistance.

The capillary tube P can collect a predetermined amount of oil accumulated in the high pressure chamber 41 into the low pressure chamber 42,
Further, the capillary tube P has the same inner diameter and length as the backflow of the high pressure gas refrigerant from the high pressure chamber 41 to the low pressure chamber 42 as much as possible, that is, the same as the conventional capillary tube is used. Is
The one end side is held by the small diameter passage 71 while one end thereof is projected from the end surface of the flange portion 73 of the guide pipe 7, and the other end side is opened into the large diameter passage 72.

Further, the guide pipe 7 is inserted into a guide hole 8 penetratingly formed in the outer peripheral portion of the partition body 5, and a large step portion 81 is formed in the guide hole 8, and the step portion 81 is formed. The flange portion 73 is received, and the guide pipe 7 is press-fitted into the guide hole 8 to be supported.
Is inserted into the space formed between the outer peripheral surfaces of the first scroll 2 and the frame 11 and the casing 1.

The drive shaft 12 is attached to the frame 11.
Of the eccentric shaft portion 17 is opened in one end, and the other end is the outer peripheral surface of the frame 11 and the guide hole 8 a.
Oil passage 11 that opens at the same position in the circumferential direction with respect to
b, the casing 1 of the oil passage 11b is formed.
The protruding portion side of the T-shaped connecting pipe 91 is connected to the opening to the inside, and the guide pipe 7 is connected to the partition body side opening of the straight portion of the connecting pipe 91 to connect the connecting pipe 91. The low pressure chamber 42 between the frame 11 and the motor M is opened. Further, the guide body 93 that covers the opening 92 of the connection pipe 91 to the low pressure chamber 42 and guides the oil flowing out from the opening 92 to the core cut portion M2 formed on the outer peripheral surface of the stator M1 of the motor M is provided. It is attached to the inner peripheral surface of the casing 1 so that the oil flowing through the guide pipe 7 is caused to flow to the core cut portion M2 through the connecting pipe 91 and the guide body 93 to prevent the return oil from mixing with the suction gas. I am trying to do it.

As described above, in the second embodiment, the small diameter passage 71 opening to the high pressure chamber 41 and the large diameter passage 72 opening to the low pressure chamber 42 and having a diameter larger than the small diameter passage 71 are continuously formed. The long guide pipe 7 formed in the guide pipe 7 is formed, the capillary tube P is inserted into the small diameter passage 71 in the guide pipe 7, and the one end side of the capillary tube P is held in the small diameter passage 71. Since the oil return passage 6 is formed by the guide pipe 7 and the capillary tube P such that the other end of the tube P is opened in the large-diameter passage 72, the capillary tube P causes the high-pressure chamber 41 to exit from the high-pressure chamber 41. The amount of oil returned to the low-pressure chamber 42 can be made the same as in the conventional case, and the backflow of the high-pressure gas refrigerant can be minimized, while the guide pipe 7 and the The return pipe 91 and the guide body 93 can prevent the return oil from being sucked into the compression element CF together with the suction gas from the suction pipe 14, so that the oil is returned from the high pressure chamber 41 to the oil sump 10. It can be done reliably.

Further, since the capillary tube P can be held by the guide pipe 7 and the whole can be protected by the guide pipe 7, as a result, the guide pipe 7 having the capillary tube P and high rigidity can be provided. Since the assembling work can be performed only by assembling the guide tube 8 into the guide hole 8, deformation of the capillary tube P at the time of assembling can be prevented and the assembling property can be improved.

Further, in the guide pipe 7, since the small diameter passage 71 has a short length for holding the capillary tube P, the formation of the small diameter passage 71 becomes easier as compared with the first embodiment. The guide pipe 7 can be easily processed.

Further, since the capillary tube P is projected from the guide pipe 7 on the high pressure chamber 41 side, the projecting height of the capillary tube P is particularly high when it is applied to a vertical scroll compressor. Since dust mixed with oil or the like can be stored in the guide hole 8, dust can be prevented from entering the capillary tube P and clogging of the capillary tube P can be prevented.

Further, in the second embodiment, since the guide pipe 7 has high rigidity, it is not necessary to protect the guide pipe 7 from the gas flow, and the outer peripheral surfaces of the first scroll 2 and the frame 11 and the casing. The guide pipe 7 can be arranged in a space formed between the oil return passage 6 and the inner peripheral surface of the oil return passage 6. When the scroll type compressor is used in the horizontal type, the degree of freedom of the forming position is widened, and it is possible to form the scroll type compressor in conformity with the oil reservoir 10, and it is easy to apply.

Further, the oil return passage 6 is connected to the connecting pipe 9
The oil passage 11 for the oil returning from the crank chamber 11a by 1
b, and the return oil from both sides is guided by the guide body 93 in the oil sump 10 so that the influence of the disturbance caused by the rotation of the drive shaft 12 is small, and the risk of mixing into the intake gas is small. Be drained at
The oil can be collected in the oil reservoir 10 more reliably.

In the second embodiment, the return oil from the crank chamber 11a is joined to the oil return passage 6, but it is not always necessary to join the return oil, and the guide having the large diameter passage 72 is not necessarily required. The pipe 7 may be extended to near the core cut portion M2.

Furthermore, the oil return passages 6 of the first and second embodiments can be applied to both vertical and horizontal scroll type compressors.

[0053]

According to the first aspect of the present invention, the small-diameter passage 71 allows the amount of oil returned from the high-pressure chamber 41 to the low-pressure chamber 42 to be the same as in the conventional case, and the backflow of the high-pressure gas refrigerant is achieved. Since the return oil can be prevented from being sucked into the compression element CF together with the suction gas from the suction pipe 14 by the large diameter passage 72, the capillary tube having a small diameter is used. Instead, the oil can be reliably returned from the high pressure chamber 41 to the oil reservoir.

Further, since the oil return passage 6 is formed from the guide pipe 7 having a large outer diameter as compared with the conventional capillary tube having a small outer diameter, the rigidity thereof can be increased, and as a result, Since it is possible to prevent the deformation at the time of assembling into the guide hole formed for inserting the guide pipe 7, it is possible to improve the assembling property.

Further, since the guide pipe 7 has high rigidity, it is not always necessary to insert it into a long guide hole for protecting the guide pipe 7 from the gas flow, and the end portion of the guide pipe 7 on the high pressure chamber side is not required. Just to support
Since the other portion can be exposed in the low pressure chamber 42, the formation position of the oil return passage 6 is not limited, and as a result, the degree of freedom of the formation position of the oil return passage 6 is expanded. When the scroll type compressor is used in the horizontal type, it is possible to form it according to the oil sump and it is easy to apply.

According to the second aspect of the present invention, the high pressure chamber 41 to the low pressure chamber 4 are moved by the capillary tube P.
It is possible to make the amount of oil returned to No. 2 equal to that of the conventional one, and further, while suppressing the backflow of the high-pressure gas refrigerant to the minimum, the amount of oil returned by the guide pipe 7 together with the intake gas from the intake pipe 14 causes the return oil to be compressed. Since it can be prevented from being sucked into the CF, the oil can be reliably returned from the high pressure chamber 41 to the oil reservoir while using the capillary tube P having a short length.

Furthermore, since the capillary tube P can be held by the guide pipe 7 and the whole can be protected by the guide pipe 7, as a result, the guide pipe 7 having the capillary tube P and high rigidity can be provided. Since the assembling work can be performed only by assembling the guide tube into the guide hole or the like, the capillary tube P can be prevented from being deformed at the time of assembling and the assembling property can be improved.

Further, since the guide pipe 7 may have a short length for holding the small diameter passage 71 for holding the capillary tube P, the small diameter passage 71 can be easily processed as its length is shortened. The processing of the guide pipe 7 can be easily performed.

Further, since the capillary tube P can be projected from the guide pipe 7 on the high pressure chamber 41 side, the projecting height of the capillary tube P is particularly high when it is applied to a vertical scroll compressor. Since dust mixed with oil or the like can be collected, it is possible to prevent dust from entering the capillary tube P.
It is possible to prevent clogging of the capillary tube P.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of essential parts showing a first embodiment of a scroll compressor of the present invention.

FIG. 2 is a vertical sectional view showing the overall structure of the first embodiment.

FIG. 3 is an enlarged sectional view of an essential part showing a second embodiment of the scroll compressor of the present invention.

FIG. 4 is a vertical sectional view showing the overall structure of the second embodiment.

FIG. 5 is a graph showing the relationship between the length of the capillary tube and the flow rate of oil and the leak amount of gas.

FIG. 6 is a cutaway vertical sectional view showing a conventional scroll type compressor.

FIG. 7 is a vertical cross-sectional view showing another conventional scroll compressor.

[Explanation of symbols]

 1 Casing 13 External Discharge Pipe 14 Suction Pipe CF Compression Element 2 First Scroll 22 Discharge Port 3 Second Scroll 41 High Pressure Chamber 42 Low Pressure Chamber 6 Oil Return Passage 7 Guide Pipe 71 Small Diameter Passage 72 Large Diameter Passage P Capillary Tube

Claims (2)

[Claims] 1. A casing (1) is internally provided with a compression element (CF) having first and second scrolls (2) and (3), and the compression element (CF) is provided on one side of the compression element (CF). 2) and the external discharge pipe (13) are open to the high pressure chamber (41), the suction pipe (14) is opened to the low pressure chamber (42) is formed on the other side, the high pressure chamber (41 ) And low pressure chamber (4
In a scroll type compressor provided with an oil return passage (6) for collecting the oil accumulated in the high pressure chamber (41) in the low pressure chamber (42), the opening to the high pressure chamber (41). Oil is provided by a long guide pipe (7) in which a small diameter passage (71) and a large diameter passage (72) that is open to the low pressure chamber (42) and is larger in diameter than the small diameter passage (71) are continuously formed. A scroll type compressor characterized in that a return passage (6) is formed. 2. A small diameter passage (7) in the guide pipe (7).
The capillary tube (P) is inserted into 1) and the one end side of the capillary tube (P) is held by the small diameter passageway (71), and the capillary tube (P) is held.
The other end of the opening is opened into the large diameter passage (72).
The scroll compressor described.