JPS6332186A - Rotary blower - Google Patents

Abstract

PURPOSE:To reduce loss volume and improve efficiency by forming one rotor side of a part which forms said loss volume with an epicycloid curve while the other rotor side with a hypocycloid curve and a small arc part. CONSTITUTION:Two rotors 40 having the same configuration are provided so as to be engagedly rotated with each other in the space inside a housing 10. Each of the rotors 40 has large circular arc parts 42 on both end parts of its larger diameter line while small circular arc parts 44 on both end parts of its smaller diameter line. And, the part from the large circular arc part 42 to the small circular arc part 44 is formed into a shape consisting of an epicycloid curve 46 and a hypocycloid curve 48 in order. By this structure, since the epicycloid curve 46 approximates to a contour formed by the hypocycloid curve 48 and small arc part 44, the volume of a loss volume space part 50 is reduced, improving the efficiency of a blower.

Description

[Detailed description of the invention] [Industrial use! ? ] A: Part II relates to a rotary blower, especially a pair of rotors 1.
The present invention relates to a rotary blower that reduces the loss volume caused by the gap 111].

[Description of the Prior Art IjI] Rotary blowers used in compressors, compressors, etc. are classified into Roots-type rotary blowers and Wankel-type rotary blowers, depending on the external shape of the rotor.

Here, an example of a conventional general Roots-type rotary blower is shown in FIG. 4 as a cross-sectional view of the main part.
An internal space 16 is formed which communicates with the suction port 12 on one side and with the discharge port 114 on the other side. This internal space 16 is
The cross section of the space is such that the wall surface 18 has an external shape obtained by intersecting two circles. Inside the internal space 16, rotating shafts 20 rotated by driving means (not shown) are arranged at the center positions of six circles in the cross section of the space, and rotors 22 having the same shape are fixed to the rotating shafts 20, respectively. . Those two rotating shafts 20! I] rotate in the opposite direction. The shape of the rotor 22 is set so that the rotors 22 are always in contact with each other when the rotating shaft 20 rotates. The configuration described above is a necessary configuration for all types of rotary blowers.

Here, a feature of the rotor of the Roots type rotary blower is that the point is the maximum length from the center of rotation in the cross section of the rotor 22. That is, the roots-type rotor 22
is configured to contact the wall surface 18 of the housing 10 at a point 24 (Japanese Patent Application Laid-open No. 75793/1983). In this roots type rotor, the rotor 22 is connected to the housing 1.
Since line contact is made with the wall surface 18 of 0, there is a drawback that airtightness cannot be maintained sufficiently at the contact point.

In order to improve this drawback, a Wankel type blower (Japanese Patent Application Laid-open No. 149032/1983) as shown in FIGS. 5 and 6 has been proposed. The cross-sectional shape of the rotor of the Wankel type blower shown in FIG. 5 is symmetrical with respect to two directions perpendicular to each other around the rotation axis 20, and the rotor of the Wankel type blower shown in FIG. It has a shape that is symmetrical with respect to one direction centered on the rotation axis 20. A feature of these Wankel type blowers is that the maximum length from the center of rotation in the cross section of the rotor 26a shown in No. 51 ill and the rotor 26b shown in FIG. 6 is a circular arc 128a628b, respectively. is li
Since the Wankel type rotor 26a/Φ26b is in contact with the wall surface 18 of the housing 10 at an arcuate surface, the rotors 26a, 26b and the wall surface 18 of the housing 10 are in contact with each other.
It is possible to maintain sufficient airtightness at the point of contact.

In FIG. 5, the outer shape of the rotor in this Wankel type blower includes the large arc portion 28a for contacting the wall surface 18 of the housing 10, and the large arc portion 28a on the other side.
A small arc portion 30a for contacting with the large arc portion 2
8a and the small arc portion 30a.
2a (the side closer to the large arc portion 28a) and the second straight portion 34a (
(the side closer to the small arc portion 30a).

The outer shape of this rotor includes a large arc portion 28a and a small arc portion 30.
a is formed at two locations, and each of the first straight line 1 part 32a and the -th straight line IIIA part 34a is formed at four locations. The boundaries between each of these circular arc parts and the straight line parts and the boundaries between the straight parts are connected by smooth curves (circular arcs or cycloid curves).

In addition, the external shape of the rotor of the Wankel type blower in FIG.
A small circular arc portion 30b for contacting with b, a first linear portion 32b (the side near the large circular arc portion 28b) and a second linear portion 34b for connecting the large circular arc portion 28b and the small circular placing portion 30b.
(the side near the small 1r7 corner 30b). The outer shape of this rotor includes a large arc portion 28b and a small arc portion 3.
0b is formed at one location each, and the first straight portion 32b and the second straight portion 34b are each formed at two locations.

In these Wankel type blowers, when the rotors rotate, two points of contact between the two rotors simultaneously, and spaces 36a and 36b (Fig. 5 and 6) surrounded by the two contact points are formed. arise. This space 36aφ36b is in a sealed state, and the air inside is not sent out to the discharge side but is pushed toward the suction side. Due to the spaces 36a and 36b, a part of the air amount that should be sent out to the discharge side is pushed back to the suction side, causing a loss volume.

[Problems to be Solved by the Invention] As shown in FIGS. 5 and 6UA, the spaces 36a and 36b that cause loss volume in conventional Wankel type blowers are those in which one rotor is straight (the first straight line). Department)
and the other rotor is surrounded by a straight line (the second line part) and a small arc part. That is, the space 36a and the space 36b that cause loss volume are large and surrounded by two straight lines and one small arc. Therefore, in the conventional Wankel type blower, the loss polyme amounted to about 5% of the intake air F, X:. The larger this loss volume becomes, the worse the planting effect + becomes, and there are problems in that the temperature of the blower itself increases and noise is generated.

[Object of the Invention] The present invention has been made in view of the above points, and is intended to minimize the space that causes volume loss, thereby improving volumetric efficiency.

The present invention provides a rotary blower that can prevent temperature rise and noise generation.

[Means for Solving the Problems] In order to achieve the above object, the present invention forms an internal space in the housing, rotatably provides a plurality of rotors of the same shape in the internal space, and each The cross-sectional shape of the rotor (
i? The rotor has a large circular arc portion that slides on the wall surface of the internal space and a small circular arc portion that slides on the large circular arc portion of another rotor, and the cross-sectional external shape of the rotor lies along two orthogonal axes centered on the rotation axis. In a rotary blower with a symmetrical shape, +
A rotor cross section connecting the large circular arc portion and the small circular arc portion described in i'ij [I′i+ an epicycloid curve whose outer shape is continuous with the large circular arc portion and along a fixed circle centered on the rotation center of the rotor, One is continuous with its epicycloid curve and the other is Ii
It consists of a small circular arc portion and a continuous hypocycloid curve along a fixed circle centered on the rotation center of the rotor.

[The space that generates the working colossal volume is formed mainly in an epicycloid shape on one rotor side.

The other rotor side is formed with an outer shape consisting of a hypocycloid and a small arc portion. That is, based on the condition that the rotors can slide into contact with each other, the outer shape of one side of the space where loss volume occurs is made closer to the outer shape of the other side.

Therefore, the space that causes the loss volume is smaller than the space formed by a conventional straight line.

[Example] Next, the present invention will be explained based on the drawings.

FIG. 1 shows a cross-sectional view of a rotary blower according to the present invention.
In Fig. 1, the same reference numerals as in Figs. 4 to 6 indicate the same parts. It is an enlarged side view showing a part.

The center of rotation of the rotor 40 is the intersection of the X-axis and the Y-axis. The outer shape (quarter minus) of this rotor 40 is determined from the intersection with the X axis by Y
Each point of abcde, which will be described later, is connected to the intersection with the axis. Also.

The entire outer shape of the rotor 40 is defined by the outer shape shown in FIG.
The curve is made symmetrical about the Y axis and the intersection thereof, and is made into one loop curve as a whole. That is, the outer shape of the rotor 40 is symmetrical with respect to two axes orthogonal to the center of the rotation axis.

Here, the outer shape of the rotor 40 will be explained based on FIG. 2. First, the intersection with the X axis is defined as point a, and the distance from point a to point b, which is moved counterclockwise, is an arcuate curve with radius H. The angle α of the large circular arc portion 42 from point a to point b is 3
It may be set freely between '' and 30 degrees.On the other hand, Y
The intersection with the axis is defined as point e, and the distance from point e to point d, which is moved in a clockwise direction, is an arcuate curve (three small circles 44) with diameter r.The identification of point d will be described later. Also.

The relationship between half PI, R and "F-diameter r" is R/r = 2.0
~4.0. Furthermore, as shown in FIG. 1, the distance between the rotating shafts 20 of the two rotors 40 is R+r.

Next, the area between the above point and the zero point is an epicycloid curve 46. This epicycloid curve 46 is a curve formed by a moving circle with radius q=p/6 to p/2 rotating along a fixed circle with radius p=(R+r)/2. This 0 point is a fixed circle and an epicycloid curve 46
It is the intersection with After that, from point 0 to point d, the radius is p
Hypocycloid by a moving circle of radius q along the fixed circle of As shown in FIG. 2, four connected curves from point a to point e in FIG. 2 are connected to form one continuous curve to form the entire outer shape of the rotor.

Here, the reason for limiting the range of each numerical value in ;ij is explained in theory 1.
Follow the rules. First, 'l', diameter R and -1! , and the diameter r is defined as R/r=2, 0 to 4, 00')Q.

this is.

This is because when R/r < 2, the cross-sectional area of the rotor 40 in the internal space 16 increases and the discharge amount decreases, and when R/r > 4, the angle α of the large arc with radius R is 3° or less. There is a risk that airtightness may not be maintained.

Next, the radius q of the moving circle was set in the range of p/6 to p/2.

When q<p/6, this becomes the hypopsychotic curve 4.
This is because the connecting portion between 8 and the small arc portion 44 is hollowed out, and the space where loss volume occurs becomes large.On the other hand, when q>p/2, R/r<2. Rotor 40 disconnection tr1i Seedlings become thicker and discharge rI
This is because the knee is reduced.

Furthermore, the angle of the large arc of the toy R was set to α-3° to 30°. This is because when α is less than 3°, airtightness cannot be maintained and the rotary blower cannot be effective.
If the temperature exceeds 100°, the cross-sectional area of the rotor becomes hot and the discharge amount decreases. That is, when α is 30' or more, the discharge amount cannot be ensured unless the shape is as shown in FIG. 6 (the shape of the rotor is symmetrical about only one axis).

In addition, in order to form a cycloid, it is necessary to make a moving circle of radius q along a fixed circle of radius p reach the large circular arc part 42 of radius 't' and the small circular arc part 44 of radius r. That is, in order for the moving circle to reach the large circular arc portion 42 with radius R and the small circular arc portion 44 with radius r, q>(R−r)/4 is a necessary condition. Here, when p=(R+r)/2 is combined with the above necessary conditional expression, p/q<2 (R+ r)/
(R-r).

Further, the fixed circle radius is not limited to p=(R+r)/2, but as long as it is within the range of ±20%, it is possible to reduce the space where loss volume occurs.

A graph combining these elements is shown in Figure 3.
Those that satisfy all of the above ranges are the hatched areas surrounded by thick lines in this graph.Within the range that satisfies each element such as 0 or more, the outer shape of the rotor is defined as a large circular arc portion 42.
It is followed by an epicycloid curve 46, followed by a hypocycloid curve 48. It is composed of a small circular arc portion 44 having a diameter r and a small circular arc portion 44 following it. This results in loss in unreleased IJI.

The space section 50 (first ['4]) that generates the volume is a space surrounded by the epicycloid curve 46, the hypocycloid curve 48, and the small circular arc section 44 of {l'-diameter r.

Since this epicycloid curve 46 is a curve closer to the outer shape of the hypocycloid curve 48 and the small circular strong portion 44 with radius r, the space portion 50 can be made smaller. In reality, the loss volume in the case of unreleased air 1 could be suppressed to 1% of intake air 25.

Incidentally, in the above embodiment, the rotor is 2 (y4), but it is also applicable to a rotor of 3 (y4).

[Effects of the Invention] As described below, according to the rotary blower according to the present invention, one rotor forming the loss volume has an epicycloid curve, and the other rotor has a hypocycloid curve and a small arc portion. It was made to consist of That is, since the shapes of both sides are set so that the curve on one side forming the loss volume is closer to the curve on the other side, the loss volume can be significantly reduced compared to the conventional one. As a result, it is possible to improve the volumetric efficiency, and also to prevent temperature rise and noise generation.

Furthermore, in the case of unreleased 1!1, the ratio of the radius of the large arc portion to the radius of the small arc portion and the angle of the large arc portion can be selected as El tb within a predetermined range. Therefore, it is possible to freely set the pitch between the rotating axes of each rotor, the ratio of the longitudinal length of the rotor to the radius of the large arc, etc., and it is possible to freely set the length and size. .

[Brief explanation of the drawing]

Figure 1 is a cross section of the rotary blower related to Unexploded II, 4.
FIG. 2 is an enlarged side view showing a quarter of the side surface of the rotor used in the rotary blower of FIG. The figure is a sectional view of the main parts of a conventional general Roots-type rotary blower.
6 and 6 are sectional views of essential parts of a conventional general Wankel type rotary blower. 10...Housing, 16...
Internal space, 18...Wall surface, 20...
... Rotating shaft, 40 ... Rotor, 4
2... Large circular arc part, 44... Small circular arc part, 46... Epicycloid curve, 48...
...Hypocycloid curve. No. 40 1.5 Figure 6 Procedural Amendment (Voluntary) August 21, 1985 Commissioner of the Patent Office Kuro 1) Akio Yu 1. Display of 119 items 1 ■ Japanese Patent Application No. 171888 of 1988 2, Title of the invention: Rotary blower 3, person making the amendment/relationship with the case Patent applicant address: 6-13-11, Sotokanda, Chiyo III-ku, Tokyo Name: Mikuni Kogyo Co., Ltd. Representative: Student 1) Norihiro Mitsuru 4, Agent Person 〒10771 story 03-582-0944
Address: 903 Hosokawa Building, 1-1-17 Akasaka, Minato-ku, Tokyo
No. 6, Number of expressions increased by amendment] None 7, "Title of the invention" column of the application subject to amendment and "Detailed description of the invention IJ1" in the specification 8, ? lli Correct contents (1) Regarding the application, it is as per the attached application 8. Contents of amendment (1) Add j to r after "the two points of contact" on page 6, line 9 of the specification . (2) "α is 3 degrees or less" on page 11, line 13 of the specification is corrected to rα of 39 and y41. (3) "α is 3° or less" on page 12, line 4 of the specification is r
Correct α to less than 3° to 1. (4) Effects of the rotary blower from line 5 of page 12 of the specification to line 6 of the same page [1, “When α becomes 30° or more” are the same effects as the T rotary blower. become unable to demonstrate
If α is larger than 30", it will be corrected to 1. (5) Specification page 12, line 8 [Correct 1 "30° or more" to J larger than r30". (6) Specification No. "The number of rotors is two, but there are three or more" in the first to second lines of page 14, which means that the r rotor is two blades,
Corrected to ``3 leaves or more''. that's all

Claims (2)

[Claims] (1) An internal space is formed in the housing, a plurality of rotors of the same shape are rotatably provided in the internal space, and each rotor has a large circular arc portion in sliding contact with the wall surface of the internal space in the cross-sectional external shape of the rotor, etc. A rotary blower having a small circular arc portion in sliding contact with a large circular arc portion of the rotor, and the cross-sectional shape of the rotor is symmetrical with respect to two orthogonal axes centered on the rotation axis. The rotor cross-sectional outline connecting the circular arc part and the small circular arc part is an epicycloid curve that is continuous with the large circular arc part and follows a fixed circle centered on the rotation center of the rotor;
A rotary blower characterized in that one side is continuous with the epicycloid curve, and the other side is a hypocycloid curve along a fixed circle centered on the rotation center of the rotor, which is continuous with the small arc portion. (2) The ratio of the radius R of the large arc portion to the radius r of the small arc portion is R/r = 2.0 to 4.0, and the radius of the fixed circle of the epicycloid curve and hypocycloid curve is p. = (R + r) / 2 ± 20%, and the radius of the moving circle of the cycloid curve along the fixed circle is q = p / 6 ~ p / 2
The rotation according to claim 1, wherein the angle of the large arc is in the range of 6° to 60°, and p/q<2(R+r)/(R−r). Type blower.