JPS6229601B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to scroll fluid machines such as scroll compressors and scroll expanders.

[Conventional technology]

Conventional scroll fluid machines are known, for example, from JP-A-54
-81513, and its main configuration is shown in Figures 1 and 2.

〓〓〓
In FIGS. 1 and 2, the stationary scroll member 1 consists of an end plate 1a and a lap 1b standing upright thereon. The orbiting scroll member 2 consists of an end plate 2a and a lap 2b similar to the stationary scroll member 1. The laps 1b, 2b of both scroll members 1, 2 are formed into an involute or a curved line approximating it, and have substantially uniform thickness and uniform height.

A port 3 is provided at the center of the end plate 1a of the stationary scroll member 1, and another port 4 is provided at the outer circumferential side. Port 3 serves as a discharge port in the case of a compressor, and serves as an inflow port in the case of an expander.

Port 4 is the suction port in the case of a compressor,
In the case of an expander, this is the discharge port.

A scroll pin 2c is provided protruding from the back surface of the orbiting scroll member 2.

Both scroll members 1 and 2 have laps 1b and 2b.
are engaged with each other facing each other. In this state, the winding end 1b' of each wrap 1b, 2b,
2b' are located 180 degrees apart from each other.

The frame 5 includes an end plate 1 of the stationary scroll member 1.
It is fixed to the outer periphery of a with several bolts.

The crankshaft 6 is supported by the frame 5 by two bearings 7 and 8 attached to the frame 5. A balance weight 9 is attached to this crankshaft 6.
are integrally formed. The balance weight 9 may be separate from the crankshaft 6.

A boss hole 10 is formed in the head of the crankshaft 6. The boss hole 10 has its center at a position offset by a distance ε from the axis 0 of the crankshaft 6, and the scroll pin 2c is fitted into the boss hole 10. A needle bearing 11 is provided between the boss hole 10 and the scroll pin 2c.

The rotation prevention member 12 is provided between the back surface of the end plate 2a of the orbiting scroll member 2 and the frame 5. The rotation prevention member 12 is ring-shaped and has a straight groove (not shown) on a surface facing the end plate 2a and a surface facing the frame 5. The groove provided on the surface facing the frame 5 is orthogonal to the groove provided on the surface facing the end plate 2a. An Oldham key 13 fixed to the frame 5 is fitted into the groove provided on the surface facing the frame, and an Oldham key 13 fixed to the end plate 2a (not shown) is fitted into the groove provided on the surface facing the end plate 2a. ) is inserted.

The mechanical seal 14 is provided at a portion where the crankshaft 6 penetrates the frame 5 and projects to the outside, and is housed in a seal housing 15. Since this mechanical seal 14 is a known one, a description of its configuration will be omitted.

When the crankshaft 6 is rotated clockwise in FIG. 1 by a prime mover (not shown), the orbiting scroll member 2 does not change its attitude with respect to the stationary scroll member 1 (apparently does not rotate on its axis). Rotate in the direction. As a result, both scroll members 1,
The working spaces V ₁ and V ₂ formed between the two reduce the volumes of the working spaces V ₁ and V ₂ while rotating clockwise, compressing the fluid taken in from the port 4 and discharging it from the port 3.

On the other hand, when the orbiting scroll member 2 rotates counterclockwise, the working spaces V ₁ and V ₂ rotate in the opposite direction to the above and gradually increase in volume, and the high temperature and high pressure that flows in from port 3 (is discharged from port 4). The gas (which is at high temperature and pressure relative to the gas) expands and exits through port 4. At this time, power is generated in the crankshaft 6.

In addition, the patent application filed before the application of the claimed invention
Publication No. 55-109792 discloses a protrusion along an arc of radius R ₁ from the center of the orbiting scroll toward the end of the winding from a position opposite to the winding end of the fixed scroll wrap on the wrap outer wall surface of the orbiting scroll member. In addition, a housing is provided whose inner wall surface is in tight contact with the outer peripheral surface of the wrap of the fixed scroll member, and a compressed space is formed by the projecting portion and the inner wall surface of the housing. .

[Problem that the invention seeks to solve]

In the former configuration, the relief 16 is provided over a range of at least 180°, preferably 200° from the winding end 1b' of the wrap 1b of the stationary scroll member 1, so that the diameter of the stationary scroll member 1 is increased. . In the case of a compressor, this escape 16 is a closed space formed at a position opposite to the port 4 (the winding end 1 of the wrap 1b of the stationary scroll member 1).
Since the space formed on the b′ side serves as a passage for the gas sucked in from the wrap 4, there is a large escape.
It is essential. In addition, the heat released from both scroll members 1 and 2, which have become high temperature due to compression heat, is used to escape 16.
It must be ensured that the suction gas passing through it does not become overheated.

For this purpose, the relief 16 must be made large, and the diameter of the scroll member becomes even larger.

In the latter case, the range of 180° on the winding end side of the outer wall surface at the lap of the orbiting scroll member can be made to contribute to compression, but in order to do so, it is necessary to form a projecting part on the lap of the orbiting scroll member and to fix it. It is necessary to provide a housing with an inner wall surface that tightly contacts the outer circumference of the lap of the scroll member, which complicates the construction. Further, the curves of the outer wall surface of the projecting portion and the inner wall surface of the housing are circular arcs, and the curves of the inner and outer wall surfaces of the wrap are involutes, and the two curves are different, making molding difficult.

An object of the present invention is to provide a scroll fluid machine that has a simple structure and is easy to mold, so that the range of about 180 degrees on the wrap end side of the wrap outer wall surface of an orbiting scroll member can serve as an operating space. It's about doing.

[Means for solving problems]

The first feature of the present invention is that the inner wall surface of the lap of the stationary scroll member is located between the end of the wrap of the stationary scroll member and the vicinity of a point opposite to the end of the wrap of the stationary scroll member and the end of the wrap of the orbiting scroll member. The inner wall surface of this extended portion smoothly extends to the end of the lap winding of the stationary scroll member and forms a curve of the same nature as the portion of the inner wall surface of the stationary scroll member excluding the extended portion. It is something that

The second feature is, in addition to the first feature,
The winding start side of the wrap in either the stationary scroll member or the orbiting scroll member is shaved off so as to satisfy the following formula compared to the wrap in the other scroll member.

λc≈α/Vr In this formula, λc: angle of scraping (radian) Vr: volume ratio (suction volume/discharge volume) α: winding angle (radian) of the lap of the stationary scroll member.

[Effect]

As mentioned above, the inner wall surface of the lap of the stationary scroll member is simply extended in a curved line from the winding end, and there is no need to add any special processing to the orbiting scroll member. The parts are curved with the same properties as the parts other than the extended parts, and are smoothly connected, so they can be easily molded.

In addition, in the second invention, since the winding start side of the wrap is shaved off, one of the pair of working spaces that is about to communicate with the port in the center communicates with the port earlier than the other. Therefore, one of the working spaces whose suction volume has been increased by the extension portion communicates with the port earlier than the other working space, and the pressures of the pair of working spaces when they communicate with the port are approximately the same. Become.

Therefore, losses caused by increased suction volume during communication between the working space and the port are eliminated.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4.

In the embodiment, parts that are the same as or correspond to the conventional ones are given the same reference numerals as in FIGS. 1 and 2, and their explanation will be omitted. The inner wall surface of the wrap 1b of the stationary scroll member 1 is extended to a point opposite the winding end 2b' of the orbiting scroll member 2. The extended portions 1b' to 1b'' smoothly extend to the winding end 2b' within a range of about 180°, and are the same involute as the wraps other than the extended portions or a curved line approximating this.

In this way, the lap 1b of the stationary scroll member 1
If the inner wall surface of the inner wall is extended, what used to be the relief 16 will now form a space that effectively contributes to compression, so the theoretical suction volume will increase by the length of the extension. At the same time, the inner wall surfaces of the extended portions 1b' to 1b'' move inward compared to when the relief 16 was formed as in the past. In addition to the diameter (size) of the hit becoming smaller, the extended part 1
Due to the movement of the inner wall surface of b′ to 1b″ inward〓〓〓
As a result, the diameter becomes even smaller, making it possible to significantly reduce the diameter.

In the case of a compressor, if the port 4 is placed close to the winding end 2b' of the orbiting scroll member 2, the working space _V3 formed outside the suction completion wrap 2b can also be Gas can also be sucked into the working space formed inside 2b under substantially the same conditions.

When the suction is completed, the volume of the working space _V3 formed outside the wrap 2b is different from the volume of the working space formed inside. just before)
When the pressure is reached, the pressures in both working spaces are different from each other. In this way, if there is a difference in the pressure discharged from each working space to port 3 and there is a failure,
Winding start 2 of wrap 2b of orbiting scroll member 2
d as shown by the dotted line, and the working space is brought into communication with the port 3 as soon as possible to make the pressures in both spaces almost equal. This will be explained in detail with reference to FIG.

The wrap 2b is formed by an inner involute 2e and an outer involute 2f.

The winding starts of both involutes 2e and 2f are e and f, respectively, but in order to prevent interference between wraps 1b and 2b and for processing problems, wrap 2 is
The winding start of the inner involute 2e of b is e', and the winding start of the outer involute 2f is f'. The angle λ ₁ radian (referred to as the winding start angle) of these curves to the start of winding is the same for both involutes 2e and 2f.

On the other hand, since the working space whose volume increases is located outside the wrap 2b of the orbiting scroll member 2, only the outer involute 2f of the wrap 2b is removed.

The scraping angle λc is inversely proportional to the volume Vr (suction volume/discharge volume).

That is, λc≈α/Vr.

α is the angle (in radians) of the extension of the port 1b of the stationary scroll member 1. Therefore, the area to be scraped is the range e', f', f'' shown by diagonal lines. Note that the winding start end e' of the inner involute 2e of the wrap 2b and the outer involute 2 of the wrap 2b are
Any curve may be used to connect the point f° of the scraping angle of f.

Note that the symbol B is the base circle.

In addition to scraping off the lap 2b of the orbiting scroll member 2 as described above, only the inner involute of the stationary scroll member 1 may be scraped off under the same conditions as described above. If there is no problem even if there is an unbalance in the pressure discharged from the working space to the port 3, there is no need to process the wrap 2b or the wrap 1b.

Although the lap 1b of the stationary scroll member 1 is extended by 180 degrees compared to the conventional one, the range of extension can be arbitrarily selected as long as it is within about 180 degrees.

In addition to extending the outer wall surface of the lap of the stationary scroll member, shortening the lap of the orbiting scroll member within a range of 180°, extending the lap of the stationary scroll member, and shortening the lap of the orbiting scroll member. It also falls within the scope of this invention to use the above methods together.

〔Effect of the invention〕

As explained above, according to the first invention,
It is possible to provide a scroll fluid machine that has a simple structure and is easy to mold so that a range of about 180° on the winding end side of the wrap outer wall surface of an orbiting scroll member can serve as an operating space. According to the second invention, in addition to the effects of the first invention, it is possible to provide a scroll fluid machine in which there is no loss caused by increased suction volume when the working space communicates with the central port. can.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional plan view of a conventional scroll fluid machine, FIG. 2 is a cross-sectional view cut along the line -- in FIG. 1, FIG. 3 is a cross-sectional plan view of an embodiment of the present invention, and FIG. 4 is a stationary It is an enlarged view of the winding start part of a scroll member. 1... Stationary scroll member, 2... Orbiting scroll member, 1a, 2a... End plate, 1b, 2b...
Rap, 3, 4...Port, 5...Frame, 6
... Crankshaft, 7, 8 ... Bearing, 9 ... Balance weight, 12 ... Rotation prevention member, 13 ... Oldham key, 14 ... Mechanical seal. 〓〓〓

Claims (1)

[Scope of Claims] 1. A stationary and orbiting scroll member having an end plate and a spiral wrap having a thickness and height that stands upright on the end plate, the ends of the wraps being approximately 180 degrees apart from each other. In cases where the laps of the stationary scroll member are engaged with each other in a shifted state, and the orbiting scroll member orbits so as not to apparently rotate relative to the stationary scroll member, the inner wall surface of the lap of the stationary scroll member is opposite to the stationary scroll member. It extends from the winding end of the wrap of the member to a position between the winding end and the vicinity of a point opposite to the winding end of the wrap of the orbiting scroll member, and the inner wall surface of this extended portion is connected to the stationary scroll member. 1. A scroll fluid machine characterized in that the scroll fluid machine has a curve that smoothly extends to the end of the wrap of the stationary scroll member and has the same characteristics as a portion of the inner wall surface of the wrap of the stationary scroll member excluding the extended portion. 2. The scroll fluid machine according to claim 1, wherein the extended portion of the stationary scroll member has a wrapping angle of 180°. 3. A stationary and orbiting scroll member having an end plate and a spiral wrap having a thickness and height that stands upright on the end plate, and the ends of the wraps are offset by approximately 180° from each other, and the ends of the scroll members are mutually lap-to-lap. In the case where the orbiting scroll member orbits in such a manner that it does not appear to rotate relative to the stationary scroll member, the inner wall surface of the lap of the stationary scroll member extends from the winding end of the wrap of the stationary scroll member. , is extended to a position between the end of the winding and a point near a point opposite to the end of the wrap of the orbiting scroll member, and the inner wall surface of this extended portion is smooth against the end of the wrap of the stationary scroll member. and has the same characteristics as the inner wall surface of the stationary scroll member's wrap excluding the extended portion, and the winding start side of the wrap of either the stationary scroll member or the orbiting scroll member is connected to the other side. A scroll fluid machine characterized in that the lap of the scroll member is shaved off so as to satisfy the following formula. λc=α/Vr Where, λc: Angle of scraping (radian) Vr: Volume ratio (suction volume/discharge volume) α: Wrapping angle of the extended portion of the lap of the stationary scroll member (radian)