JP2008297977A - Scroll type fluid machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scroll-type fluid machine capable of preventing increase in the amount of coolant leakage caused by aggravation of mutual hitting of wraps formed on movable/fixed scrolls and improving volume efficiency of the fluid machine. <P>SOLUTION: The fluid machine comprises a root part 58 having a taper face 60 inclined from a taper end 60a positioned on a side surface 44a of a wrap 44 toward a mirror plate surface 40a with the wrap standing thereon and a chamfering part 68 formed on a wrap 42 paired with a wrap having a root part by chamfering from a chamfer end 70 positioned on the side surface 42a toward a tip face 42b of the wrap 42. Along with forming a slidable contact surface 66, the chamfering part is separated from the root part and formed to have a size that a distance from the chamfer end to the slidable contact surface is as long as or longer than a distance from the taper end to the slidable contact surface. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a scroll type fluid machine, and more particularly to a scroll type fluid machine suitable for use in a refrigeration air conditioner or a heat pump type hot water heater.

This type of scroll fluid machine, for example, a hermetic scroll compressor, has a series of suction, compression, and discharge of a working fluid (hereinafter referred to as a refrigerant) as the movable scroll revolves with respect to the fixed scroll in the housing. The process is implemented.
Specifically, spiral wraps are provided on the end plate surfaces of the movable and fixed scroll end plates, respectively, and these laps cooperate to form a compression chamber, and the volume of the compression chamber is reduced to reduce the volume of the above-described series. The process is implemented. And the technique which chamfers the front-end | tip of a lap | wrap is well-known (for example, refer patent documents 1-4).
Japanese Utility Model Publication No. 62-76185 JP 2001-329972 A JP 2004-76629 A Japanese Utility Model Publication No. 62-82391

Incidentally, the lap is generally formed by cutting using a cutting tool such as an end mill. At this time, if the cutting tool is aged and worn at the tip thereof, the root portion of the wrap is formed in a tapered shape in accordance with the amount of wear of the cutting tool.
However, in each of the above prior arts, no special consideration is given to the processing error of the base portion of the lap due to such wear of the cutting tool. There is a problem that the amount of refrigerant leaked increases and the volumetric efficiency of the compressor decreases.

  The present invention has been made in view of such a problem, and prevents an increase in the amount of leaked refrigerant due to deterioration of the hit between the wraps formed on the movable and fixed scrolls, thereby improving the volume efficiency of the fluid machine. It is an object of the present invention to provide a scroll type fluid machine capable of performing the above.

  In order to achieve the above object, the scroll type fluid machine according to claim 1 is provided with a fixed and a movable scroll each having a spiral wrap standing on the end plate surface of the end plate in the housing, and is movable relative to the fixed scroll. A scroll-type fluid machine that performs a series of processes from suction to discharge of working fluid by forming a sliding contact surface by sliding the revolving orbiting motion of the scroll to the end plate surface of the pair of wraps. A root portion formed on one or both of the movable and fixed scrolls, and having a tapered surface inclined from a tapered end positioned on the side surface of the wrap toward the end plate surface on which the wrap is erected And from a chamfered end that is formed on a lap that is paired with a lap having a root portion and is positioned on a side surface of the wrap toward the distal end surface of the wrap. The chamfered portion is formed by chamfering, and the chamfered portion is separated from the root portion with the formation of the slidable contact surface, and the distance from the chamfered end to the slidable contact surface is equal to or greater than the distance from the tapered end to the slidable contact surface. It is characterized by being formed into a size.

  Further, in the invention according to claim 2, in claim 1, the root portion is formed by chamfering from the taper surface to the end plate surface, and further has an R surface for positioning the R end on the end plate surface, In addition to having a second chamfered end on the distal end surface, the distance from the second chamfered end to the side surface of the wrap having the root portion is increased from the R end to the side surface as the sliding contact surface is formed. It is characterized by being formed in a size that is equal to or greater than the distance.

Further, in the invention described in claim 3, in claim 2, the chamfered portion is positioned at the taper end position and the second chamfer end is positioned at the R end position along with the formation of the sliding contact surface. It is characterized by that.
Furthermore, the invention according to claim 4 is characterized in that, in any one of claims 1 to 3, the chamfered portion is composed of two or more tapered surface groups.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the chamfered portion includes an arc-shaped portion.
Furthermore, in the invention described in claim 6, in any one of claims 1 to 5, the working fluid is a refrigerant made of carbon dioxide.

  According to the scroll fluid machine of the first aspect of the present invention, the chamfered portion of the other lap paired with at least one lap having the root portion is formed from the chamfered end of the wrap side surface to the tip end surface of the wrap, The distance between the chamfered end and the slidable contact surface is greater than the distance from the taper end to the slidable contact surface. Thereby, the chamfered portion is formed large so as not to interfere with the base portion of the pair of wraps, and the side surfaces of the wraps can be reliably brought into contact with the formation of the sliding contact surface. Therefore, even if a taper surface is formed at the root portion of the lap due to wear of a cutting tool such as an end mill when cutting the lap, an increase in the amount of refrigerant leaked due to deterioration in the contact between the laps can be prevented. The volumetric efficiency of can be improved.

  According to the second aspect of the present invention, the root portion is formed by chamfering from the taper surface to the end plate surface, and further has an R surface for positioning the R end on the end plate surface, and the chamfered portion is the tip surface of the wrap. Has a second chamfer end. Then, the chamfered portion is separated from the root portion with the formation of the sliding contact surface, and the distance from the second chamfered end to the side surface of the wrap having the root portion is larger than the distance from the R end to the side surface. Formed. Thereby, even if an R surface is formed in addition to the tapered surface at the root portion of the wrap, an increase in the amount of refrigerant leaked due to deterioration of the hit between the wraps can be prevented, and the volume efficiency of the fluid machine can be further improved. it can.

  Furthermore, according to the invention described in claim 3, the chamfered portion is positioned at the taper end position and the second chamfer end is positioned at the R end position along with the formation of the sliding contact surface. As a result, the gap volume between the chamfered portion and the root portion, which is not related to the formation of the compression chamber, that is, the dead volume between the wraps can be reduced, and the amount of refrigerant leaking from the compression chamber can be increased through the dead volume. Therefore, the volume efficiency of the fluid machine can be further improved.

Furthermore, according to the invention described in claim 4, since the chamfered portion is formed of a group of two or more tapered surfaces, the chamfered portion can be formed closer to the root portion, thereby further reducing the dead volume. The volume efficiency of the fluid machine can be further improved.
Further, according to the invention described in claim 5, since the chamfered portion includes the arc-shaped portion, the chamfered portion can be formed closer to the root portion, so that the dead volume can be reduced as much as possible. And the volumetric efficiency of the fluid machine can be further improved.

  Furthermore, according to the invention described in claim 6, since the working fluid is a refrigerant made of carbon dioxide, the fluid machine operates in a higher pressure / high-speed rotation region than in the case of using other refrigerants. Although there is concern about an increase in the amount of refrigerant leaked, the above-described configuration can make the volume efficiency improvement effect of the fluid machine more remarkable.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
First, the first embodiment will be described.
FIG. 1 shows a hermetic scroll compressor as an example of a fluid machine according to an embodiment of the present invention. The compressor 1 is incorporated in a refrigeration circuit such as a refrigeration air conditioner or a heat pump type hot water heater. The circuit includes a path through which carbon dioxide refrigerant, which is an example of a working fluid, circulates. The compressor 1 sucks the refrigerant from the path, compresses it, and discharges the refrigerant toward the path.

  The compressor 1 includes a housing 2, and an upper lid 6 and a lower lid 8 are fitted in an airtight manner on the upper side and the lower side of the body portion 4 of the housing 2, respectively. The discharge pressure is acting. A suction pipe 10 for sucking the refrigerant taken in from the circuit is connected to an appropriate position of the body 4, and a discharge pipe 12 for sending the compressed refrigerant in the housing 2 to the circuit is connected to an appropriate position of the upper lid 6. Has been.

An electric motor 14 is accommodated in the body 4, and a rotating shaft 16 is disposed in the motor 14. The rotating shaft 16 is driven by energization of the motor 14. Further, the upper end side of the rotating shaft 16 is rotatably supported by the main shaft frame 18 via a bearing, and the main shaft frame 18 is integrally fixed to the housing 2.
On the other hand, the lower end side of the rotating shaft 16 is rotatably supported by the countershaft frame 20 via a bearing. An oil pump 22 is attached to the lower end side of the rotary shaft 16, and the pump 22 sucks lubricating oil in an oil storage chamber 24 formed inside the lower lid 8. This lubricating oil ascends in the oil supply passage 26 drilled in the axial direction in the rotary shaft 16 and is supplied from the upper end of the rotary shaft 16 to the motor 14, scroll unit 28, etc. Functions as a sliding surface seal. At this time, the fact that the refrigerant discharge pressure acts on the oil surface of the lubricating oil in the oil storage chamber 26 also contributes to the increase of the lubricating oil in the oil supply passage 26. Further, a lubricating oil inlet 30 is formed at an appropriate position of the countershaft frame 20, and the lubricating oil supplied to each sliding portion in the compressor 1 is stored in the oil storage chamber 24 via the inlet 30. Is done.

The unit 28 is disposed above the motor 14 in the body 4 and performs a series of processes of refrigerant suction, compression and discharge.
Specifically, the unit 28 includes a movable scroll 34 and a fixed scroll 36, and the movable scroll 34 includes an end plate 38, and an end plate surface 38 a of the end plate 38 extends toward the end plate 40 of the fixed scroll 36. A spiral wrap 42 is erected, and a spiral wrap 44 extending toward the end plate 38 is also erected on the end plate surface 40 a of the end plate 40 of the fixed scroll 36.

These wraps 42 and 44 cooperate with each other, and form a compression chamber by sucking refrigerant from the outer peripheral side space of the end plate 38 and the suction chamber communicating with the suction pipe 10. The volume of the compression chamber is reduced while moving from the radially outer peripheral side of the wraps 42 and 44 toward the center by the revolving orbiting motion of the movable scroll 34 with respect to the fixed scroll 36.
A boss 46 is formed on the back side of the end plate 38 in order to give the orbiting scroll 34 the above-mentioned orbiting scroll 34, and the boss 46 rotates to an eccentric shaft 48 integrally formed on the upper end side of the rotary shaft 16 via a bearing. It is supported freely. The rotation of the movable scroll 34 is blocked by a rotation blocking pin (not shown).

  On the other hand, the fixed scroll 36 is fixed to the spindle frame 18, and the end plate 40 partitions the compression chamber side and the discharge chamber 50 side. A discharge hole 52 communicating with the compression chamber side is formed through the end plate 40 at an appropriate position in the central portion of the fixed scroll 36, and this discharge hole 52 is disposed on the discharge chamber 50 side of the fixed scroll 36. The discharge valve 54 is opened and closed. Further, the discharge chamber 50 side of the fixed scroll 36 including the discharge valve 54 is covered with a discharge head 56, and this discharge head 56 suppresses noise when the discharge valve 54 is opened.

  According to the compressor 1 described above, as the rotary shaft 16 rotates, the movable scroll 34 revolves without rotating. The revolving orbiting motion of the movable scroll 34 sucks the refrigerant taken into the body portion 3 through the suction pipe 10 from the suction chamber toward the inside of the unit 28 and compresses the compressed refrigerant by the unit 28. Are discharged from the discharge hole 52. Then, the refrigerant discharged from the discharge hole 52 circulates in the housing 2, reaches the discharge chamber 50, and is sent out of the compressor 1 through the discharge pipe 12.

By the way, as shown in the enlarged view of the wraps 42 and 44 in FIG. 2, the wrap 44 has a root portion 58 continuous from the end plate surface 40a on its side surface 44a. The root portion 58 is formed at the stage of cutting the lap 44 with a cutting tool such as an end mill, and includes a tapered surface 60 and an R surface 62.
The tapered surface 60 is tapered at a predetermined inclination angle A with respect to the axial direction of the fixed scroll 36 from the tapered end 60a positioned on the side surface 44a toward the end plate surface 40a. The position of the taper end 60a and the inclination angle A are determined according to the degree of wear of the end mill tip used for cutting, etc., and a predetermined type of end mill is uniformly used, and the replacement frequency may be changed according to the use condition of the end mill. If set in advance, the variation range of the position of the taper end 60a and the inclination angle A can be predicted to some extent.

On the other hand, the R surface 62 is R chamfered with a predetermined radius r from a boundary point 60b that forms a boundary with the tapered surface 60 to the end plate surface 40a, and the R end 62a of the R surface 62 is positioned on the end plate surface 40a. . That is, the R surface 62 smoothly connects the end plate surface 40a and the tapered surface 60 with an arc having a radius r.
On the other hand, the tip portion 64 formed from the side surface 42a to the tip surface 42b of the wrap 42 has a slidable contact surface 66 formed by sliding the tip surface 42b against the end plate surface 40a when the orbiting scroll 34 revolves. Forming.

Here, a chamfered portion 68 is formed at the distal end portion 64, and the chamfered portion 68 is a tapered surface end (second chamfered end) that is positioned on the distal end surface 42b from a side tapered end (chamfered end) 70 positioned on the side surface 42a. End) 72 is formed as a tapered surface 74 chamfered.
As the sliding surface 66 is formed, the taper surface 74 is positioned such that the side taper end 70 is at a distance greater than or equal to the position of the taper end 60a in the axial direction of the movable scroll 34 from the end plate surface 40a. Is formed at a distance equal to or greater than the position of the R end 62a in the radial direction of the movable scroll 34 from the side surface 44a of the wrap 44.

  That is, in the present embodiment, the chamfered portion 68 is changed to the root portion 58, that is, the tapered surface, in consideration of the position of the taper end 60 a predicted at the root portion 58 of the wrap 44 and the variation range of the inclination angle A of the tapered surface 60. It is formed large so as not to interfere with 70 and the R surface 62. Thereby, when the movable scroll 34 revolves, the side surfaces 42a and 44a of the wraps 42 and 44 can be reliably brought into contact with each other as the sliding contact surface 66 is formed. Therefore, even when the tip of a cutting tool such as an end mill is worn when the lap 44 is cut and the taper surface 60 is formed at the root portion 58 of the processed lap 44, the contact of the lap 42 with the lap 44 is deteriorated. The increase in the amount of refrigerant leaked from the compression chamber due to the above can be prevented, and the volumetric efficiency of the compressor 1 can be improved.

  Here, as shown by a dotted line in FIG. 2, the position of the taper end 60a and the inclination angle A are specified in advance when the lap 42 is processed after the lap 44 is processed, or when the lap 42 is reprocessed or modified. When possible, the chamfered portion 68 is formed so that the side taper end 70 is positioned at the position of the taper end 60a and the tip surface side taper end 72 is positioned at the position of the R end 62a as the sliding contact surface 66 is formed. Is preferred. In this case, the volume of the gap 76 between the movable wrap 42 and the fixed wrap 44 that is not related to the formation of the compression chamber, that is, the dead volume V can be reduced.

  Since the pressure of the dead volume V is lower than the pressure in the compression chamber, the large dead volume V means that the receiving volume of refrigerant leaking from the compression chamber in the unit 28 increases, This is an acceleration factor for an increase in the amount of refrigerant leaked from the chamber. Therefore, this factor can be eliminated by reducing the dead volume, and the volume efficiency of the compressor 1 can be further improved.

Next, a second embodiment will be described.
As shown in FIG. 3, the chamfered portion 78 of the second embodiment is formed of first and second taper surfaces (taper surface group) 80 and 82, and the other configuration is the same as that of the first embodiment. Therefore, differences from the first embodiment will be mainly described.
The first taper surface 80 is tapered at a predetermined inclination angle A1 with respect to the axial direction of the fixed scroll 36 from the side taper end 70 toward the tip surface 42b side, while the second taper surface 82 is the first taper surface 80. The taper is processed at a predetermined inclination angle A2 from the boundary point 80a with the second taper surface 82 to the tip end side taper end 72. That is, the chamfered portion 78 is formed in a two-step taper shape having a convex shape toward the root portion 58 with the sliding contact surface 66 formed, and at least the inclination angle A1 is the inclination angle of the tapered surface 60. It is set larger than A, and the inclination angle A2 is set such that the boundary point 80a is separated without contacting the root portion 58.

  Here, in FIG. 3, with the formation of the sliding contact surface 66, the chamfered portion 78 is such that the side taper end 70 is positioned at the taper end 60a and the tip surface side taper end 72 is positioned at the R end 62a. However, at least the side taper end 70 is positioned at a distance equal to or larger than the position of the taper end 60a in the axial direction of the movable scroll 34 from the end plate surface 40a, and the front end side taper end 72 extends from the side surface 44a to the movable scroll 34. What is necessary is just to form so that it may be located in the radial direction at the distance more than the position of R end 62a.

As described above, similarly to the first embodiment, in the compressor 1 according to the second embodiment, the side surfaces 42a and 44a of the wraps 42 and 44 are reliably brought into contact with each other as the sliding contact surface 66 is formed. An increase in the amount of refrigerant leaked from the compression chamber can be prevented, and the volume efficiency of the compressor 1 can be improved.
Particularly in the case of the second embodiment, the dead volume V can be further reduced as compared with the chamfered portion 68 of the first embodiment, and the volume efficiency of the compressor 1 can be further improved.

Further, the chamfered portion 78 is not limited to the two-step tapered shape, and may be formed in a multi-step tapered shape having three or more steps that form a convex shape toward the root portion 58 in a state where the sliding contact surface 66 is formed. In this case, it is preferable that the dead volume V can be further reduced and the volume efficiency of the compressor 1 can be further improved.
Although the description of one embodiment of the present invention has been completed above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  For example, in each of the above-described embodiments, the tip portion 64 of the wrap 42 is chamfered in a tapered shape or a multi-step tapered shape, but for example, an ellipse or arc that forms a convex shape toward the root portion 58 along with the formation of the sliding contact portion 66 ( You may chamfer into the curved surface form which forms a part of (arc-shaped part). Further, the tip end portion 64 may be chamfered in a shape combining such a tapered surface and a curved surface. In these cases, the side surfaces of the wraps 42 and 44 are formed along with the formation of the sliding contact surface 66 in the same manner as described above. 42a and 44a can be reliably brought into contact with each other, and the dead volume V can be reduced as much as possible. As a result, an increase in the amount of refrigerant leaked from the compression chamber can be reliably prevented, and the volume efficiency of the compressor 1 can be greatly improved.

  Further, in each of the above embodiments, the case where the root portion is formed on the wrap 44 of the fixed scroll 36 and the chamfered portion is formed on the wrap 42 of the movable scroll 34 has been described, but conversely, the root portion is formed on the wrap 42. Needless to say, the present invention can be applied to the case where the chamfered portion is formed on the wrap 44 and the case where the root portion and the chamfered portion are formed on both the wraps 42 and 44.

  Furthermore, in each of the above embodiments, carbon dioxide is used as the refrigerant, but the present invention is not limited to this. However, since carbon dioxide is used as a refrigerant, the movable scroll 34 rotates in a high pressure / high rotation range, and therefore operates in a higher pressure / high rotation range than when other refrigerants are used. However, the above-described configuration can prevent this and make the effect of improving the volume efficiency of the compressor 1 more remarkable.

  Furthermore, in each of the above embodiments, a sealed scroll compressor incorporated in a refrigeration circuit such as a refrigeration air conditioner or a heat pump type hot water heater has been described. Or it is applicable to scroll type fluid machines, such as an expander.

1 is a longitudinal sectional view showing a hermetic scroll compressor according to a first embodiment of the present invention. It is the figure which expanded and showed the chamfering part which concerns on 1st Embodiment of this invention. It is the figure which expanded and showed the chamfering part which concerns on 2nd Embodiment of this invention.

Explanation of symbols

1 Scroll compressor (scroll type fluid machine)
2 Housing 34 Movable scroll 36 Fixed scroll 38a, 40a End plate surface 42, 44 Wrap 42a, 44a Side surface 42b Tip surface 58 Root portion 60 Tapered surface 60a Tapered end 62 R surface 62a R end 66 Sliding surface 68, 78 Chamfered portion 70 Side surface side Taper end (Chamfer end)
72 Tip side taper end (second chamfer end)
80 1st taper surface (taper surface group)
82 2nd taper surface (taper surface group)

Claims (6)

A housing includes a fixed and a movable scroll each having a pair of spiral wraps standing on the end plate surface of the end plate, and the movable scroll revolves with respect to the fixed scroll. A scroll type fluid machine that performs a series of processes from suction to discharge of a working fluid, with a tip surface slidingly contacting the end plate surface of the other lap to form a sliding contact surface,
A root portion formed on at least one of the wraps and having a tapered surface inclined from a tapered end positioned on a side surface of the wrap toward the end plate surface on which the wrap is erected;
A chamfer formed on the other lap paired with the at least one lap having the root portion and chamfered from the chamfer end positioned on the side surface of the wrap to the tip end surface of the wrap;
The chamfered portion is formed so as to be separated from the base portion and to have a distance from the chamfered end to the slidable contact surface equal to or greater than a distance from the tapered end to the slidable contact surface as the slidable contact surface is formed. Scroll type fluid machine characterized by being made. The root portion further includes an R surface formed by chamfering from the taper surface to the end plate surface and positioning an R end on the end plate surface;
The chamfered portion has a second chamfered end on the distal end surface, and with the formation of the sliding contact surface, the chamfered portion is separated from the root portion and has the root portion from the second chamfered end. 2. The scroll fluid machine according to claim 1, wherein the scroll type fluid machine is formed so that a distance to a side surface is equal to or greater than a distance from the R end to the side surface.   3. The chamfered portion according to claim 2, wherein the chamfered portion is positioned at the position of the tapered end and the second chamfered end is positioned at the position of the R end together with the formation of the sliding contact surface. The scroll type fluid machine as described.   The scroll type fluid machine according to any one of claims 1 to 3, wherein the chamfered portion includes two or more tapered surface groups.   The scroll fluid machine according to any one of claims 1 to 4, wherein the chamfered portion includes an arc-shaped portion.   The scroll type fluid machine according to any one of claims 1 to 5, wherein the working fluid is a refrigerant made of carbon dioxide.

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