WO2011040341A1 - Scroll fluid machine - Google Patents

Abstract

Provided is a scroll fluid machine which can resolve problems caused by revolving, turning, and driving an orbiting scroll while the orbiting scroll is inclined, and can improve the performance and durability thereof. The scroll fluid machine is provided with a pair consisting of a stationary scroll and an orbiting scroll, wherein spiral wraps (31) stand on end plates (30). The stationary scroll and the orbiting scroll are engaged so that the spiral wraps (31) are opposite to each other while shifting the phases. In the scroll fluid machine, offset portions (36, 37) are provided on the front side surface and the back side surface of the tip portion of each spiral wrap (31) of either the stationary scroll and/or the orbiting scroll, and are provided from the inner peripheral end portion to the outer peripheral end portion of the spiral wrap (31) in the direction that the thickness of the wrap is reduced.

Description

Scroll fluid machinery

The present invention relates to a scroll fluid machine that can be applied to a compressor, a pump, an expander, and the like.

The scroll fluid machine generally includes a pair of fixed scroll and orbiting scroll in which spiral wraps are erected on an end plate. The fixed scroll and the orbiting scroll make the spiral wraps face each other and have a 180 degree phase. It is set as the structure meshed by shifting. In such a scroll fluid machine, for example, a compressor, the spiral wraps of the fixed scroll and the orbiting scroll are brought into contact with each other, and the space between the tooth tip surface of the spiral wrap and the tooth bottom surface of the counterpart scroll is sealed and sealed. By forming the compressed chamber, the performance is improved by reducing leakage of the compressed gas from the wrap gap, the tip gap, and the like as much as possible.

However, in the scroll compressor, the orbiting scroll is driven to revolve around the fixed scroll by a crankshaft connected to a boss portion provided at the center of the rear surface of the end plate via a bush or the like. It is said that. For this reason, the orbiting scroll is revolved and driven while being tilted by the moment due to the gas pressure acting in the height direction of the spiral wrap standing on the opposite surface of the end plate and the centrifugal force accompanying the orbiting revolution. Between the fixed scroll and the orbiting scroll, the tooth tip portion of the spiral wrap is strongly in contact with the spiral wrap surface of the counterpart scroll. As a result, the wear on the tip portion of the spiral wrap is accelerated, the power is increased, and the stress applied to the root portion of the spiral wrap is increased, which impedes the durability of the scroll compressor. there were.

On the other hand, for example, as shown in Patent Documents 1 and 2, etc., the wrap thickness is reduced in a partial region along the spiral direction of the ventral side surface and / or the back side surface of the spiral wrap of the fixed scroll and the orbiting scroll. Proposals have been made in which the spiral wraps are not in contact with each other in a partial region by providing an offset portion in the direction.

Japanese Patent Laid-Open No. 2001-173584 (see FIGS. 1 and 6) JP 2009-174406 A (see FIG. 3-5)

However, in Patent Document 1, an offset portion is provided in a predetermined region at the start of winding of a spiral wrap to prevent performance degradation due to overcompression and to achieve high efficiency. However, it is not possible to solve the above-mentioned problem that occurs due to the revolution turning driving while tilting. Moreover, the thing of patent document 2 provides thermal expansion in the case where the fixed scroll and the orbiting scroll are made of different materials by providing an offset portion at a part including the start of the spiral wrap or a part including the end of the winding. It is intended to prevent local contact between the spiral wraps due to the difference in quantity and to achieve high efficiency, which also occurs due to the revolution scroll being driven while the orbiting scroll is tilted. The above problems cannot be solved.

Furthermore, as shown in Patent Documents 1 and 2, in the case where the offset portion is provided in a partial region of the spiral wrap, the offset portion is usually provided in the entire height direction of the spiral wrap. There are almost cases. However, in such a configuration, the amount of gas leakage from the offset portion is increased, and the efficiency is reduced accordingly, so how to suppress the reduction in efficiency is a problem.

The present invention has been made in view of such circumstances, and solves the problems caused by the revolution scroll being driven while the orbiting scroll is tilted, thereby improving performance and improving durability. An object of the present invention is to provide a scroll fluid machine that can be realized.

In order to solve the above problems, the scroll fluid machine of the present invention employs the following means.
That is, the scroll fluid machine according to one aspect of the present invention includes a pair of fixed scrolls and orbiting scrolls in which spiral wraps are erected on an end plate, and the fixed scrolls and orbiting scrolls are arranged between the spiral wraps. In a scroll fluid machine that is opposed to each other and meshed out of phase with each other, on the ventral side and the back side of the tooth tip portion of the spiral wrap of at least one or both of the fixed scroll and the orbiting scroll. An offset portion is provided in the direction of decreasing the wrap thickness from the inner peripheral end portion to the outer peripheral end portion.

According to the scroll fluid machine according to one aspect of the present invention, from the inner peripheral end portion of the spiral wrap to the outer peripheral end of the tooth tip portion of the spiral wrap of the fixed scroll and / or the orbiting scroll. Since the offset part is provided in the direction of decreasing the wrap thickness over the part, even if the orbiting scroll is tilted by being driven by the orbiting revolution, the tooth tip portion of the spiral wrap is between the fixed scroll and the orbiting scroll. The situation where it contacts the spiral wrap surface of the counterpart scroll can be avoided by the offset portion. Therefore, when the orbiting scroll is tilted, the stationary scroll and the orbiting scroll's tooth tip portion of the orbiting scroll are brought into strong contact with each other, resulting in accelerated wear or increased power, or at the root of the spiral wrap. It is possible to alleviate the increase in stress and the like, and to improve the performance and durability of the scroll fluid machine.

In the scroll fluid machine, the fixed scroll and the orbiting scroll are each provided with a step at an arbitrary position along the spiral direction of the spiral wrap, and the wrap height on the outer peripheral side of the spiral wrap is the inner periphery. The fixed scroll and the orbiting scroll are set higher than the lap height on the side, and the offset portion is at least the inner peripheral end portion of the spiral wrap on the outer peripheral side of the stepped portion having a higher wrap height. It is good also as a structure provided over the outer peripheral end part.

According to this configuration, the step is provided at any position along the spiral direction of the spiral wraps of the fixed scroll and the orbiting scroll, and the wrap height on the outer peripheral side of the spiral wrap is higher than the wrap height on the inner peripheral side. In particular, since the offset portion is provided from the inner peripheral end portion to the outer peripheral end portion of the spiral wrap on the outer peripheral side with respect to the stepped portion at which the lap height is increased, By providing an offset portion at the tooth tip portion of the spiral wrap on the outer peripheral side than the step portion whose wrap height is increased by providing the step portion, the outer spiral wrap is increased by providing the offset portion. It is possible to mitigate the acceleration of wear and power in the portion, the increase in stress generated in the root portion, and the like. Therefore, the characteristics of the scroll fluid machine in which the step portion is provided in the scroll spiral direction can be further improved, and the scroll fluid machine can be further improved in performance.

In the scroll fluid machine, the offset portion spans the entire range of the spiral wrap portion on the outer peripheral side of the step portion and the spiral wrap portion on the inner peripheral side of the step portion across the step portion, It is good also as a structure provided from the inner peripheral end part of the said spiral wrap to the outer peripheral end part.

According to this configuration, the offset portion extends over the entire range of the spiral wrap portion on the outer peripheral side of the step portion and the spiral wrap portion on the inner peripheral side of the step portion across the step portion. Since it is provided from the inner peripheral end portion to the outer peripheral end portion, the spiral wrap portion on the outer peripheral side than the step portion where the wrap height is increased and the inner periphery than the step portion where the wrap height is lowered If the orbiting scroll is revolved and driven in the entire range with the spiral wrap portion on the side, the spiral wrap is not moved between the two scrolls even if it is tilted in the ventral or back direction of the spiral wrap. The offset portion can avoid a situation where the tooth tip portion contacts the spiral wrap surface of the counterpart scroll. Accordingly, the wear of the spiral wrap, the stress applied to the root of the spiral wrap, and the power of the scroll fluid machine can be reduced, respectively, and the performance and durability of the scroll fluid machine can be improved.

In the above scroll fluid machine, the offset portion is provided from the same lap height position to the tooth tip portion with respect to the outer peripheral side portion and the inner peripheral side portion of the spiral wrap across the stepped portion. Also good.

According to this configuration, since the offset portion is provided from the same height direction position to the tooth tip portion with respect to the outer peripheral side portion and the inner peripheral side portion of the spiral wrap across the stepped portion, the offset portion is processed. In doing so, the space between the inner peripheral end portion and the outer peripheral end portion of the spiral wrap can be processed all at once while holding a tool such as an end mill at the same height position. Therefore, it is possible to facilitate the processing of the offset portion of the scroll. In this case, the offset portion on the inner peripheral side of the step portion of the spiral wrap has a smaller width in the height direction where the offset portion is provided with respect to the lap height, but the wrap height is originally low. As a result, there is no particular problem.

In any of the scroll fluid machines described above, the offset portion may be provided by cutting the abdominal side surface and the back side surface of the tooth tip portion.

According to this configuration, since the offset portion is provided by cutting the belly side surface and the back side surface of the tooth tip portion of the spiral wrap, respectively, when cutting the spiral wrap with an end mill or the like, the tooth tip The offset portion can be formed by cutting the ventral side and the back side of the part in the same manner. Therefore, the offset portion can be easily processed with a slight change in the scroll processing step.

In any of the above scroll fluid machines, the offset portion may be provided substantially equally on the abdominal side surface and the back side surface of the tooth tip portion.

According to this configuration, since the offset portions are provided substantially evenly on the abdominal side surface and the back side surface of the tooth tip portion, when the orbiting scroll is driven to revolve orbit, the abdominal side and the back side of the spiral wrap are provided. Even when tilted in any direction, it is possible to avoid the situation in which the tooth tip portion of the spiral wrap contacts the spiral wrap surface of the counterpart scroll between the two scrolls by the offset portion provided substantially evenly. Accordingly, the wear of the spiral wrap, the stress applied to the root portion of the spiral wrap, and the power of the scroll fluid machine can be reduced, respectively, and the performance and durability of the scroll fluid machine can be improved.

In any of the above scroll fluid machines, the offset portion may be provided with a thickness of about 10 μm to 50 μm with respect to the wrap thickness direction of the spiral wrap.

According to this configuration, since the offset portion is provided with a thickness of about 10 μm to 50 μm with respect to the wrap thickness direction of the spiral wrap, both scrolls are tilted when the orbiting scroll is tilted during the revolution orbit driving. It is possible to reliably avoid a situation in which the tooth tip portion of the spiral wrap contacts the spiral wrap surface of the counterpart scroll, and to suppress gas leakage from the offset portion to a minimum. Accordingly, it is possible to reduce the wear of the spiral wrap and the stress applied to the root portion of the spiral wrap while suppressing the performance degradation, and improve the durability of the scroll fluid machine.

In any of the scroll fluid machines described above, the offset portion may be provided within a range of approximately 1/3 of the wrap height with respect to the wrap height direction of the spiral wrap.

According to this configuration, since the offset portion is provided within a range of approximately 1/3 with respect to the wrap height direction of the spiral wrap, both scrolls are tilted when the orbiting scroll is tilted during the revolution orbit driving. The position where the spiral wraps of the two are in strong contact with each other can be moved relatively downward from the tooth tip portion. Therefore, the stress acting on the root portion of the spiral wrap can be reduced correspondingly, and the durability of the scroll fluid machine can be improved. Moreover, compared with what provided the offset part in the whole height direction of the spiral wrap, the gas leakage from an offset part can be decreased and efficiency can be improved. Furthermore, since the height of the spiral wrap can be relatively increased, the capacity of the scroll fluid machine can be increased while maintaining its outer diameter.

In any one of the above scroll fluid machines, the offset portion is within a range of approximately 1/3 with respect to the wrap height direction of the spiral wrap on the outer peripheral side of the step portion where the wrap height is increased. It is good also as a structure provided in.

According to this configuration, the offset portion is provided in a range within approximately 1/3 with respect to the wrap height direction of the spiral wrap on the outer peripheral side of the step portion where the wrap height is increased. The position at which the spiral wraps of both scrolls are in strong contact with each other by tilting the orbiting scroll at the outer peripheral side portion of the spiral wrap having a high wrap height is moved from the tooth tip portion to a relatively lower portion. Can be moved. Therefore, the stress acting on the root portion of the spiral wrap can be reduced correspondingly, and the durability of the scroll fluid machine can be improved. Moreover, compared with what provided the offset part in the whole height direction of the spiral wrap, the gas leakage from an offset part can be decreased and efficiency can be improved. Furthermore, since it becomes possible to relatively increase the height of the spiral wrap, the capacity of the scroll fluid machine can be increased while maintaining the outer diameter of the scroll fluid machine, and a step portion is provided in the scroll spiral direction. It is possible to further improve the performance of the scroll fluid machine provided.

According to the present invention, even when the orbiting scroll is tilted by being driven to revolve orbit, the state in which the tooth tip portion of the spiral wrap contacts the spiral wrap surface of the counterpart scroll between the fixed scroll and the orbiting scroll is offset. Acceleration of wear and increase in power caused by the contact of the tip of the spiral wrap of the fixed scroll and the orbiting scroll with the tilting of the orbiting scroll. Alternatively, it is possible to alleviate an increase in stress generated at the root portion of the spiral wrap and to improve the performance and durability of the scroll fluid machine.

1 is a longitudinal sectional view of a scroll fluid machine (scroll compressor) according to a first embodiment of the present invention. It is the top view which looked at the fixed scroll and the turning scroll of the scroll fluid machine shown in FIG. 1 from the spiral wrap side. FIG. 3 is a cross-sectional view corresponding to aa in FIG. 2. FIG. 3 is a cross-sectional view taken along the line bb in FIG. 2. FIG. 3 is a cross-sectional view corresponding to cc in FIG. 2. FIG. 3 is a cross sectional view taken along the line dd in FIG. 2. It is an expanded view of the back side surface of the spiral wrap of the fixed scroll and turning scroll shown in FIG. FIG. 3 is a development view of a ventral side surface of a spiral wrap of the fixed scroll and the orbiting scroll shown in FIG. 2. It is the top view which looked at the fixed scroll and turning scroll of the scroll fluid machine concerning a 2nd embodiment of the present invention from the spiral wrap side. FIG. 10 is a cross-sectional view corresponding to AA in FIG. 9. FIG. 10 is a development view of the back side surface of the spiral wrap of the fixed scroll and the orbiting scroll shown in FIG. 9. FIG. 10 is a development view of the ventral side surface of the spiral wrap of the fixed scroll and the orbiting scroll shown in FIG. 9.

Embodiments according to the present invention will be described below with reference to the drawings.
[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a longitudinal sectional view of a scroll fluid machine according to a first embodiment of the present invention applied to a scroll compressor.
A scroll compressor (scroll fluid machine) 1 includes a housing 2 constituting an outer shell. The housing 2 includes a front housing 3 having a cylindrical compression mechanism housing portion 3A and a bearing portion 3B provided with a plurality of bearings, and a plurality of rear housings 4 that close the opening end of the compression mechanism housing portion 3A. It is set as the structure couple | bonded integrally through the volt | bolt 5 of this.

A scroll compression mechanism (fluid mechanism) 6 including a pair of fixed scroll 7 and orbiting scroll 8 is built in the housing 2. As is well known, the scroll compression mechanism 6 separates the center of the pair of fixed scrolls 7 and the orbiting scroll 8, each having a spiral wrap standing on one end plate, by the orbiting radius, and the phase of the spiral wrap. Are engaged with each other in a state of being shifted by 180 degrees, thereby forming a pair of compression chambers 9 that are point-symmetric with respect to the scroll center. The fixed scroll 7 is fixed to the inner surface side of the rear housing 4 via a plurality of bolts 10. On the other hand, the orbiting scroll 8 is supported by a thrust bearing portion 3C on the inner surface of the front housing 3 at the back of the end plate, and is driven to revolve around the fixed scroll 7 via a drive mechanism and a rotation prevention mechanism described later. Yes.

The interior of the housing 2 is divided into a low pressure chamber 11 side surrounding the periphery of the orbiting scroll 8 via a scroll compression mechanism 6 and a high pressure chamber 12 side formed on the back side of the end plate of the fixed scroll 7. A suction port 13 provided in the housing 2 is opened on the low pressure chamber 11 side, and a discharge port (not shown) is opened on the high pressure chamber 12 side. The refrigerant gas flows through the scroll compression mechanism 6. It has become so.

A main bearing 14 and a sub-bearing 15 are incorporated in the bearing portion 3B of the front housing 3, and a crankshaft (rotary shaft) 16 is rotatably supported around the axis L via the bearings 14 and 15. One end of the crankshaft (rotating shaft) 16 passes through the front housing 3 and protrudes to the outside. A pulley with an electromagnetic clutch (not shown) is coupled to the protruding end, and power is input from the outside. It is configured as follows. A crank pin 17 is provided on the other end side of the crank shaft 16.

A drive bush 18, in which a balance weight 19 is integrally formed, is fitted to the crank pin 17 so as to be swingable around the crank pin 17. Further, a floating bush 20 and a swivel bearing 21 are provided on the outer periphery of the drive bush 18. An orbiting boss provided on the rear surface of the end plate of the orbiting scroll 8 is fitted through the via. As a result, the orbiting scroll 8 is driven to orbit with the orbiting radius being variable.

Further, a ring 23 provided on the back surface side of the end plate of the orbiting scroll 8 and a thrust bearing portion 3C side are provided between the back surface of the end plate of the orbiting scroll 8 and the thrust bearing portion 3C of the front housing 3. A pin ring type rotation prevention mechanism 22 including a pin 24 is provided, and the orbiting scroll 8 is prevented from rotating. In addition, this pin ring type rotation prevention mechanism 22 is provided in several places (for example, four places) on the circumference.

Further, the bearing portion 3B of the front housing 3 is provided with a lip seal device 25 between the main bearing 14 and the sub bearing 15 for shaft-sealing the inner side and the outer side (atmosphere side) of the housing 2. ing. The lip seal device 25 is press-fitted from the inside of the front housing 3 into a lip seal device housing portion (sometimes simply referred to as a housing portion) 26 provided on the inner peripheral surface of the bearing portion 3B. 26 abuts on a stepped portion 27 provided outside (atmosphere side) 26.

In the scroll compressor 1, the fixed scroll 7 and the orbiting scroll 8 are configured as shown in FIGS. Below, the structure of the fixed scroll 7 and the turning scroll 8 is demonstrated using FIG. 2 thru | or FIG.
The fixed scroll 7 and the orbiting scroll 8 have a configuration in which a spiral wrap 31 is erected on one surface of the end plate 30, and a predetermined direction along the spiral direction of the tooth tip surface 32 and the tooth bottom surface 33 of the spiral wrap 31. Are provided with at least one step portion 34, 35, respectively. The tooth tip surface 32 has a high outer peripheral side and a lower inner peripheral side with a step 34 as a boundary, and the tooth bottom surface 33 has a deep outer peripheral side with the step 35 as a boundary (the same surface as the surface of the end plate 30). The perimeter is shallow.

In this way, by providing the step portions 34 and 35, the spiral wrap 31 is wrapped around the spiral wrap portion 31A on the outer peripheral side with respect to the step portion 34 on the tooth tip side, as shown in FIGS. The height is set higher than the wrap height of the spiral wrap portion 31B on the inner peripheral side of the step portion 34. Thus, the scroll compression mechanism 6 is configured that can three-dimensionally compress the gas trapped in the compression chamber 9 both in the circumferential direction and in the axial direction.

Further, in the present embodiment, offset portions 36 and 37 are provided on both the abdominal side surface and the back side surface of the tooth tip portion of the spiral wrap 31 in the direction of decreasing the wrap thickness with respect to the reference curve of the spiral wrap 31. It is set as the structure. The offset portions 36 and 37 straddle the stepped portion 34 on the tooth tip side, and include all of the spiral wrap portion 31A on the outer peripheral side of the stepped portion 34 and the spiral wrap portion 31B on the inner peripheral side of the stepped portion 34. Over the range, the spiral wrap 31 is provided from the inner peripheral end portion to the outer peripheral end portion.

The offset portions 36 and 37 are provided at the tooth tip portion of the spiral wrap portion 31A on the outer peripheral side from the step portion 34 whose height is higher than that of the wrap height direction and approximately 1/3 above the wrap height direction. 34 is provided from the same wrap height position to the tooth tip portion with respect to the spiral wrap portion 31B on the inner peripheral side with respect to the step portion 34 whose height is lowered across the step 34. For this reason, as shown in FIGS. 7 and 8, the offset portions 36 and 37 in the spiral wrap portion 31 </ b> B on the inner peripheral side with respect to the step portion 34 have a narrow width in the height direction.

Further, the offset portions 36 and 37 are shown in a greatly enlarged manner in FIGS. 3 to 6, but the actual dimension in the wrap thickness direction is set in a range of about 10 μm to 50 μm, and the tooth It is provided substantially evenly on the ventral side and the back side of the front part. Further, the offset portions 36 and 37 can be formed by similarly cutting the abdominal side surface and the back side surface of the tooth tip portion when the entire spiral wrap 31 is cut by an end mill or the like.

With the configuration described above, according to the present embodiment, the following operational effects can be obtained.
The scroll compressor 1 is operated by receiving power from an external drive source and rotating the crankshaft 16. When the crankshaft 16 is rotated, the orbiting scroll 8 of the scroll compression mechanism 6 is driven to revolve around the fixed scroll 7, and the pair of compression chambers 9 are moved from the outer peripheral side toward the center side while decreasing in volume. The As a result, the low-pressure refrigerant gas taken into the compression chamber 9 from the low-pressure chamber 11 is compressed, becomes a high-temperature high-pressure gas, is discharged into the high-pressure chamber 12, and is then sent out of the compressor through the discharge port. .

When the orbiting scroll 8 is driven to revolve around the fixed scroll 7, the lap surfaces of the spiral wrap 31 are slid and rotated with each other. However, gas pressure is applied in the height direction of the spiral wrap 31. Further, since centrifugal force accompanying the revolving and turning motion acts, the turning is driven while tilting in response to the overturning moment to the abdomen or the back. As a result, the tooth tip portion of the spiral wrap 31 is brought into strong contact with the spiral wrap 31 of the counterpart scroll, and a large stress repeatedly acts on the root portion of the spiral wrap 31.

However, according to the present embodiment, since the offset portions 36 and 37 are provided in the tooth tip portions of the spiral wrap 31 of the fixed scroll 7 and the orbiting scroll 8, the orbiting scroll 8 is driven to revolve orbit. Even when tilted, the offset tip 36, 37 prevents the tooth tip portion of the spiral wrap 31 from coming into contact with the spiral wrap surface of the counterpart scroll between the fixed scroll 7 and the orbiting scroll 8 and the tooth tip. The part can be non-contact.
Therefore, when the orbiting scroll 8 is inclined, the fixed scroll 7 and the tooth tip portion of the spiral wrap 31 of the orbiting scroll 8 are brought into strong contact with each other. It is possible to alleviate an increase in stress generated at the root portion and improve the performance and durability of the scroll compressor 1.

Further, in the present embodiment, in the so-called stepped scroll compressor 1 in which a step is provided at an arbitrary position along the spiral direction of the spiral wrap, the spiral wrap portion on the outer peripheral side straddles the step 34. Since the spiral wrap 31 is provided from the inner peripheral end portion to the outer peripheral end portion over the entire range of the spiral wrap portion 31B on the inner peripheral side, the orbiting scroll 8 is provided in the entire range of the spiral wrap 31. Even when tilted, the situation in which the tooth tip portion of the spiral wrap 31 comes into contact with the spiral wrap surface of the other scroll between the two scrolls can be made non-contact by the offset portions 36, 37. 31, the stress applied to the base of the spiral wrap 31 and the power of the scroll fluid machine are reduced, respectively. It can improve the performance and improving the durability of the roll compressor 1.

In this embodiment, the offset portions 36 and 37 are provided across the entire range of the spiral wrap portion 31A on the outer peripheral side and the spiral wrap portion 31B on the inner peripheral side across the step portion 34. The portions 36 and 37 may be configured to be provided from the inner peripheral end portion to the outer peripheral end portion of only the spiral wrap portion 31A on the outer peripheral side with respect to the step portion 34 whose wrap height is increased. The effect of can be obtained. In particular, in the case of the stepped scroll compressor 1, the wrap height is higher in the spiral wrap portion 31A on the outer peripheral side than the step portion, and by providing the offset portions 36 and 37 at the tooth tip portion, It is possible to mitigate the acceleration of wear, the increase in power, the increase in stress generated at the root portion, etc. at the lap portion 31A. As a result, the characteristics of the so-called stepped scroll compressor 1 can be further improved, and the scroll compressor 1 can be further improved in performance.

Further, when processing the offset portions 36 and 37 in the stepped scroll compressor 1, the tooth tips from the same height direction position with respect to the outer peripheral side portion and the inner peripheral side portion of the spiral wrap 31 across the step portion 34. Since the offset portions 36 and 37 are provided over the portion, when machining the offset portions 36 and 37, the cutting tool such as an end mill is held at the same height position from the inner peripheral end portion of the spiral wrap 31. Processing up to the outer peripheral end portion can be performed all at once, and therefore processing of the offset portions 36 and 37 of both scrolls 7 and 8 can be facilitated. In this case, the offset portions 36 and 37 on the inner peripheral side with respect to the step portion 34 have a smaller width in the height direction in which the offset portions 36 and 37 are provided with respect to the lap height. As a result, there is no particular problem.

Further, the offset portions 36 and 37 are substantially equal in thickness to the wrap thickness direction of the spiral wrap 31 by cutting the belly side surface and the back side surface of the tooth tip portion of the spiral wrap 31 respectively. It is provided as follows. For this reason, when cutting the spiral wrap 31 with an end mill or the like, the offset side 36 and 37 can be formed by cutting the abdominal side surface and the back side surface of the tooth tip portion in the same manner. When the offset portions 36 and 37 can be easily machined with a slight change of the orbit, the orbiting scroll 6 is tilted in either the ventral side or the dorsal side of the spiral wrap 31 by being driven to revolve orbit. However, the situation in which the tooth tip portion of the spiral wrap 31 is in contact with the spiral wrap surface of the other scroll between the scrolls 7 and 8 is avoided by the offset portions 36 and 37 provided substantially evenly. , The stress applied to the root portion of the spiral wrap 31 and the power of the scroll compressor 1 can be reduced.

In particular, since the offset portions 36 and 37 are provided with a thickness of about 10 μm to 50 μm with respect to the wrap thickness direction of the spiral wrap 31, when the orbiting scroll 8 is tilted, the space between the scrolls 7 and 8 is increased. In this case, it is possible to reliably avoid the situation where the tooth tip portion of the spiral wrap 31 is brought into contact with the spiral wrap surface of the counterpart scroll, and to suppress gas leakage from the offset portions 36 and 37 to the minimum. . That is, when the thickness of the offset portions 36 and 37 is less than 10 μm, there is a possibility that the tooth tip portion may come into contact. By setting the thickness to about 50 μm, it is possible to reduce the wear on the spiral wrap 31 and the stress applied to the root portion of the spiral wrap 31 while suppressing performance degradation, and to improve the durability.

Furthermore, the offset portions 36 and 37 are provided in a range within approximately 1/3 of the wrap height with respect to the wrap height direction of the spiral wrap 31. In particular, in the stepped scroll compressor 1 of the present embodiment, the offset portions 36 and 37 are in the direction of the wrap height of the spiral wrap portion 31A on the outer peripheral side with respect to the step portion 34 where the wrap height is increased. , Generally within a range of 1/3. For this reason, the position where the spiral wraps 31 of both the scrolls 7 and 8 are in strong contact with each other by tilting the orbiting scroll 8 at the outer peripheral side portion of the spiral wrap 31 where the wrap height is increased is defined as the tooth tip. It can be moved from the part to the lower part.

As a result, the stress acting on the root portion of the spiral wrap 31 can be reduced, and the durability of the scroll compressor 1 can be improved. Moreover, compared with what provided the offset parts 36 and 37 in the whole height direction of the spiral wrap 31, gas leakage from the offset parts 36 and 37 can be decreased as much as possible, and efficiency can be improved. Further, since the height of the spiral wrap 31 can be relatively increased, the capacity of the scroll compressor 1 can be increased while maintaining the outer diameter thereof, and the scroll compressor 1 or the stage can be increased. Further enhancement of the performance of the attached scroll compressor 1 can be achieved.

In the above-described embodiment, the form in which the offset portions 36 and 37 are provided in the tooth tip portions of the spiral wraps 31 of both the fixed scroll 7 and the orbiting scroll 8 has been described. It is good also as a structure which provided the offset parts 36 and 37 in the tooth tip part of the spiral wrap 31 of one scroll, and this shall also be included by this invention.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS.
This embodiment is different from the first embodiment described above in that the fixed scroll and the orbiting scroll are the conventional fixed scroll 47 and the orbiting scroll 48 that do not have the step portions 34 and 35. Since other points are the same as those in the first embodiment, description thereof will be omitted.
In the conventional scroll compressor 1, the spiral wrap 51 erected on the end plates 50 of the fixed scroll 47 and the orbiting scroll 48 has a uniform wrap height from the inner peripheral end to the outer peripheral end.

The offset portions 56 and 57 are provided on both the abdominal side surface and the back side surface of the tooth tip portion of the spiral wrap 51, respectively. As in the first embodiment, the offset portions 56 and 57 are provided in a range within approximately 1/3 of the wrap height with respect to the wrap height direction of the spiral wrap 31, and the spiral wrap 31. The thickness is about 10 μm to 50 μm.

Also in the present embodiment, when the orbiting scroll 48 is tilted during the revolving orbiting drive, the tip portion of the spiral wrap 51 between the fixed scroll 47 and the orbiting scroll 48 is offset by the offset portions 56 and 57 as in the first embodiment. It is possible to avoid contact with the spiral wrap surface of the opponent scroll and to make contactless. Therefore, when the orbiting scroll 48 is tilted at the time of the revolution orbit driving, the acceleration of the wear, the increase in power, or the vortex caused by the contact of the toothed portion of the spiral wrap 51 of the fixed scroll 47 and the orbiting scroll 48 is strongly brought about. It is possible to alleviate an increase in stress generated at the root of the wrap 51 and improve the performance and durability of the scroll compressor 1.

In addition, this invention is not limited to the invention concerning the said embodiment, In the range which does not deviate from the summary, it can change suitably. For example, in the above-described embodiment, an example is described in which the present invention is applied to an open scroll compressor that does not have a built-in drive source. However, the present invention may be applied to a hermetic scroll compressor that has a built-in motor. Of course. Needless to say, the present invention is not limited to the compressor but can be similarly applied to other scroll fluid machines such as a pump and an expander.

Furthermore, in the above-described embodiment, the example in which the tooth tip portion of the spiral wrap of the fixed scroll and the orbiting scroll is offset (cut) with respect to the reference curve to reduce the wrap thickness has been described. In the scroll in which the coating layer is provided on the surface of the wrap, the wrap thickness of the tooth tip portion may be reduced by coating except the tooth tip portion, and such an embodiment is also included in the present invention. To be included.

Moreover, although the said embodiment demonstrated the example which provided one step part in the arbitrary positions along the spiral direction of a spiral wrap, this step part is good also as a structure provided in multiple steps along the spiral direction. . Furthermore, in the above embodiment, the description is omitted, but it is needless to say that a tip seal may be provided on the tip surface of the spiral wrap.

1 Scroll compressor (scroll fluid machine)
7, 47 Fixed scroll 8, 48 Orbiting scroll 30, 50 End plate 31, 51 Spiral wrap 31A Spiral wrap portion 31B on the outer peripheral side Spiral wrap portion 34, 35 on the inner peripheral side Step portions 36, 37, 56, 57 Offset part

Claims (9)

1. A scroll having a pair of fixed scroll and orbiting scroll in which a spiral wrap is erected on an end plate, and the fixed scroll and the orbiting scroll are meshed with each other such that the spiral wrap is opposed to each other and shifted in phase. In fluid machinery,
   At least one or both of the fixed scroll and the orbiting scroll, in the direction of decreasing the wrap thickness from the inner peripheral end portion to the outer peripheral end portion of the spiral wrap tooth tip portion of the spiral wrap. A scroll fluid machine characterized in that an offset portion is provided.
2. The fixed scroll and the orbiting scroll are each provided with a step at an arbitrary position along the spiral direction of the spiral wrap, and the wrap height on the outer peripheral side of the spiral wrap is higher than the wrap height on the inner peripheral side. Fixed scroll and the orbiting scroll,
   The said offset part is provided from the inner peripheral end part of the spiral wrap of the outer peripheral side rather than the said step part by which the lap height is made high at least from the outer peripheral end part. Scroll fluid machine.
3. The offset portion extends across the entire range of the spiral wrap portion on the outer peripheral side of the step portion and the spiral wrap portion on the inner peripheral side of the step portion across the step portion. The scroll fluid machine according to claim 2, wherein the scroll fluid machine is provided from an end portion to an outer peripheral end portion.
4. The offset portion is provided from the same lap height position to the tooth tip portion with respect to the outer peripheral side portion and the inner peripheral side portion of the spiral wrap across the stepped portion. The scroll fluid machine as described.
5. The scroll fluid machine according to any one of claims 1 to 4, wherein the offset portion is provided by cutting an abdominal side surface and a back side surface of the tooth tip portion.
6. The scroll fluid machine according to any one of claims 1 to 5, wherein the offset portions are provided substantially equally on the abdominal side surface and the back side surface of the tooth tip portion.
7. The scroll fluid machine according to any one of claims 1 to 6, wherein the offset portion is provided with a thickness of about 10 µm to 50 µm with respect to a wrap thickness direction of the spiral wrap.
8. The said offset part is provided in the range within about 1/3 of the lap height with respect to the lap height direction of the said spiral wrap, The Claim 1 thru | or 7 characterized by the above-mentioned. Scroll fluid machine.
9. The offset portion is provided in a range of approximately 1/3 or less with respect to the wrap height direction of the spiral wrap on the outer peripheral side of the step portion where the wrap height is increased. The scroll fluid machine according to any one of claims 2 to 7.
   

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