阅读说明：本技术 气体压缩机 (Gas compressor ) 是由 竹差大骑 山田竜介 于 2018-01-18 设计创作，主要内容包括：在气体压缩机中,为了防止或抑制过压缩,并且防止叶片不能完全追随,在压气机(100)中,气缸(40)的内周面(41)的截面轮廓形状：(1)具有与转子50的外周面(51)最近的最接近部(部分(a)),以及距离外周面(51)最远的最远部(部分(b1))；(2)最远部偏向转子(50)的旋转方向(R)的上游侧而形成,使得压缩行程以及排出行程比吸入行程更长；(3)从最接近部到旋转方向(R)的下游侧的最远部的角度范围的部分(d,c)包括与叶片(58)的前端(58a)持续接触的椭圆形的弧(第一曲线),以及与中心轴(C)的距离(r)发生变化、平滑地连接该椭圆形的弧的端部与最远部的圆弧(第二曲线)。(In a gas compressor, in order to prevent or suppress over-compression and prevent blades from failing to follow completely, in the compressor (100), the cross-sectional profile of an inner peripheral surface (41) of a cylinder (40): (1) has a closest portion (a)) closest to the outer peripheral surface (51) of the rotor (50) and a farthest portion (b1)) farthest from the outer peripheral surface (51); (2) the farthest part is formed by being deviated to the upstream side of the rotation direction (R) of the rotor (50) so that the compression stroke and the discharge stroke are longer than the suction stroke; (3) the portion (d, C) of the angular range from the closest portion to the farthest portion on the downstream side in the rotational direction (R) includes an arc (first curve) of an ellipse that is in continuous contact with the leading end (58a) of the blade (58), and an arc (second curve) that changes in distance (R) from the central axis (C), smoothly connecting the end of the arc of the ellipse with the farthest portion.)

1. a gas compressor is provided with:

A cylinder having an inner peripheral surface;

A rotor disposed inside the inner peripheral surface, rotating around a central axis, and having an outer peripheral surface with a circular cross-sectional profile; and

A plurality of vanes provided on the rotor, protruding from the outer circumferential surface as the rotor rotates, and moving while bringing a tip edge into contact with the inner circumferential surface to form a suction stroke, a compression stroke, and a discharge stroke,

The cross-sectional profile shape of the inner peripheral surface is:

(1) having a proximal portion closest to the outer peripheral surface and a distal portion farthest from the outer peripheral surface,

(2) The farthest portion is formed so as to be offset toward an upstream side in a rotational direction of the rotor such that the compression stroke and the discharge stroke are longer than the intake stroke,

(3) The farthest portion from the closest portion corresponding to the suction stroke to the downstream side in the rotation direction includes at least a first curve in which the leading end of the vane continuously contacts due to the vane flying out as the rotor rotates, and a second curve different from the first curve in which the distance from the central axis changes and the end portion of the first curve and the farthest portion are smoothly connected, respectively.

2. The gas compressor according to claim 1,

The first curve is an arc of an ellipse different from a curve forming the cross-sectional profile shape from the farthest portion to the closest portion on a downstream side in a rotational direction of the rotor.

3. The gas compressor according to claim 1 or 2,

A curve forming the cross-sectional profile shape from the farthest portion to the closest portion corresponding to the compression stroke and the discharge stroke is defined by a specific first elliptical form having the farthest portion as a long diameter and the closest portion as a short diameter,

The first curve is formed inside the cylinder chamber with respect to a curve defined by a specific second elliptical form having the closest portion as a short diameter and the farthest portion as a long diameter, while smoothly connecting the curve defined by the specific first elliptical form from the closest portion corresponding to the suction stroke to the farthest portion in the farthest portion.

4. The gas compressor according to any one of claims 1 to 3,

The second curve is a circular arc.

5. the gas compressor according to claim 4,

The center of the arc is set on a straight line connecting the central axis and the farthest portion.

6. The gas compressor according to any one of claims 1 to 3,

The second curve is a cubic bezier curve.

Technical Field

the present invention relates to a gas compressor.

Background

A gas compressor mounted in an air conditioning system (hereinafter, simply referred to as an air conditioning system) of a vehicle or the like has a rotary vane type. The rotary vane gas compressor performs two strokes of suction, compression, and discharge of gas during one rotation of the rotor, and has a so-called two-cycle. In such a two-cycle rotary vane gas compressor, the cross-sectional contour shape of the inner circumferential surface of the cylinder is formed in an elliptical shape (see, for example, patent document 1).

Disclosure of Invention

Problems to be solved by the invention

however, in the two-cycle gas compressor, since the gas suction, compression, and discharge strokes are performed while the rotor is rotating by 180 degrees, the compression period is short, and the compression chamber is easily over-compressed at a pressure higher than a predetermined pressure. Therefore, in order to extend the compression stroke, the elliptical shape of the cross-sectional profile of the inner circumferential surface of the cylinder may be formed in a shape in which the position of the major axis of the ellipse (the farthest portion where the inner circumferential surface of the cylinder and the outer circumferential surface of the rotor are farthest from each other) is shifted toward the intake stroke side (the upstream side in the rotation direction of the rotor).

However, as the position of the major axis is shifted toward the intake stroke side, the change in the contour shape from the position of the minor axis of the ellipse (the closest portion of the inner circumferential surface of the cylinder closest to the outer circumferential surface of the rotor) to the position of the major axis on the downstream side in the rotational direction of the rotor becomes large, and the vane protruding from the rotor as the rotor rotates cannot completely follow the change in the contour shape, and the tip of the vane is easily separated from the inner circumferential surface of the cylinder. Therefore, the position of the major axis cannot be greatly deviated to the intake stroke side, and the effect of preventing or suppressing the over-compression cannot be sufficiently exhibited.

the present invention has been made in view of the above circumstances, and an object thereof is to provide a gas compressor capable of preventing or suppressing over-compression and preventing a blade from failing to follow completely.

Means for solving the problems

The present invention is a gas compressor, including:

a cylinder having an inner peripheral surface;

A rotor disposed inside the inner peripheral surface and having an outer peripheral surface having a circular cross-sectional outline shape and rotating around a central axis; and

A plurality of vanes provided on the rotor, protruding from the outer circumferential surface as the rotor rotates, and moving while bringing a tip edge into contact with the inner circumferential surface to form a suction stroke, a compression stroke, and a discharge stroke,

The cross-sectional profile shape of the inner peripheral surface:

(1) Having a proximal portion closest to the rotor and a distal portion furthest from the rotor,

(2) The farthest portion is formed so as to be offset toward an upstream side in a rotational direction of the rotor such that the compression stroke and the discharge stroke are longer than the intake stroke,

(3) A portion from the closest portion corresponding to the suction stroke to the farthest portion on the downstream side in the rotation direction includes at least a first curve in which the leading end of the vane is continuously in contact due to the vane flying out as the rotor rotates, and a second curve different from the first curve in which the distance from the central axis changes and the end portion of the first curve and the farthest portion are smoothly connected, respectively.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the gas compressor of the present invention, it is possible to prevent or suppress over-compression and to prevent the blades from failing to follow completely.

drawings

Fig. 1 is a sectional view of a compression mechanism portion in a compressor as one embodiment of the present invention.

Fig. 2 is a view showing only the cross-sectional profile shape of the inner peripheral surface of fig. 1.

Fig. 3 is a graph showing an example of the correspondence relationship between the rotation angle [ degree ] of the rotor and the protrusion length [ mm ] of the blade (without restriction of the inner peripheral surface).

Detailed Description

hereinafter, embodiments of a gas compressor according to the present invention will be described with reference to the drawings. Fig. 1 is a sectional view of a compression mechanism portion 60 in a compressor 100 as an embodiment of the present invention.

< summary >

The compressor 100 is of a rotary vane type, and the cross-sectional profile of the inner peripheral surface 41 of the cylinder 40, which the tips 58a of the vanes 58 protruding from the rotor 50 contact, is formed by two curves different from each other from the closest portion to the farthest portion on the downstream side in the rotation direction R of the rotor 50.

< gas compressor >

The compressor 100 is configured as a part of an air conditioning system (hereinafter, simply referred to as an air conditioning system) mounted on a vehicle, and is provided in a circulation path of a cooling medium together with other components of the air conditioning system, such as a condenser, an expansion valve, and an evaporator. The compressor 100 compresses a refrigerant gas G (gas) as a gaseous cooling medium drawn from an evaporator of an air conditioning system, and supplies the compressed refrigerant gas G to a condenser of the air conditioning system. The compressor 100 includes: as shown in fig. 1, the compression mechanism 60 sucks low-pressure refrigerant gas G into the casing, compresses the sucked refrigerant gas G to a high pressure, and discharges the compressed refrigerant gas G to the outside.

As shown in fig. 1, the compression mechanism 60 includes a rotary shaft 59, a rotor 50, a vane 58, a cylinder 40, and two side blocks 20 and 30. The cylinder 40 has an inner peripheral surface 41 of a contour shape (cross-sectional contour shape) in the cross section shown in fig. 1. The rotor 50 is formed in a cylindrical shape having a circular outer peripheral surface in a sectional profile shape. The rotor 50 is disposed inside the inner circumferential surface 41 of the cylinder 40. The rotor 50 rotates about the central axis C in the clockwise direction R in fig. 1 integrally with the rotating shaft 59 fitted in the center portion thereof.

The vanes 58 are protrudably provided to the rotor 50 from the outer peripheral surface 51. The plurality of blades 58 are provided at equal angular intervals around the central axis C (for example, 5 blades are provided at an interval angle of 72[ degrees ]). Each vane 58 is disposed inside a vane groove formed in the rotor 50. Each vane 58 is provided so as to protrude from the outer peripheral surface 51 of the rotor 50 along the vane groove by receiving a load outward from the outer peripheral surface 51 of the rotor 50 due to a centrifugal force generated by rotation of the rotor 50 and a hydraulic pressure acting on the back pressure chamber 52 formed at the innermost side of the vane groove.

The two side blocks 20 and 30 are disposed so as to cover the end surfaces of the cylinder 40 and the rotor 50, respectively, and rotatably support a rotary shaft 59 protruding from the end surfaces of the rotor 50. One side block (front block) 20 covers an end surface on a side close to a suction chamber (not shown) of the compressor 100, which guides low-pressure refrigerant gas G introduced from the outside, and the other side block (rear block) 30 covers an end surface on a side close to a discharge chamber (not shown), which guides high-pressure refrigerant gas G discharged to the outside.

In fig. 1, the rear block 30 is disposed on the rear side of the cylinder 40 and the rotor 50, and thus is visually recognized as a solid body. On the other hand, the front block 20 is disposed on the front side of the cylinder 40 and the rotor 50 in fig. 1, and therefore is not visually recognized as a solid body, but is indicated by a bracketed symbol to indicate the presence on the front side.

In this way, the compression mechanism 60 has two cylinder chambers 53 and 54 formed therein with a generally crescent-shaped cross-sectional profile by the inner peripheral surface 41 of the cylinder 40, the outer peripheral surface 51 of the rotor 50, and the inner side surfaces of the two side blocks 20 and 30. The two cylinder chambers 53, 54 are formed rotationally symmetrically with respect to the center axis C.

Each of the cylinder chambers 53 and 54 is partitioned into a plurality of spaces by vanes 58 protruding from the outer peripheral surface 51 of the rotor 50. That is, the leading end 58a of the protruding vane 58 is pressed and contacted to the inner circumferential surface 41 of the cylinder 40, while the rotor 50 rotates in the clockwise direction R. Each space partitioned by the vane 58 is a compression chamber 55 whose volume changes with the rotation of the rotor 50 in the clockwise direction R.

The compression chamber 55 has a volume that increases with the rotation of the rotor 50, and forms an intake stroke in which low-pressure refrigerant gas G is taken into the interior, a compression stroke in which the volume decreases to compress the refrigerant gas G to a high pressure, and a discharge stroke in which the volume further decreases to near zero and the refrigerant gas G is discharged to the exterior.

In the intake stroke, the refrigerant gas G is drawn into the compression chamber 55 through the intake port 21 formed in the front side block 20 and the intake passage 48 formed in the cylinder 40. On the other hand, the refrigerant gas G compressed to a high pressure in the compression chamber 55 is discharged to the outside through a discharge port (not shown) formed in the cylinder 40.

In this way, the compression mechanism section 60 rotates the rotor 50 by rotating the rotary shaft 59 about the central axis C in the clockwise direction R in fig. 1 using an on-vehicle engine as a power source or, if the compressor 100 itself has an electric motor as a power source. In the compression mechanism 60, the compression chamber 55 formed in the upper cylinder chamber 53 and the compression chamber 55 formed in the lower cylinder chamber 54 in fig. 1 perform a series of cycles of the intake stroke, the compression stroke, and the discharge stroke, respectively.

Therefore, each compression chamber 55 is arranged to perform a series of cycles of the intake stroke, the compression stroke, and the discharge stroke twice (once on the cylinder chamber 53 side and once on the cylinder chamber 54 side) while the rotor 50 rotates once. The two intake strokes, the two compression strokes, and the two discharge strokes are set within a rotationally symmetrical range shifted by 180[ degrees ] from the center axis C of the rotary shaft 59.

< Cross-sectional contour shape of inner peripheral surface of Cylinder >

Fig. 2 is a view showing only the cross-sectional profile shape of the inner peripheral surface 41 of fig. 1. Next, the details of the cross-sectional contour shape of the inner circumferential surface 41 of the cylinder 40 of the compressor 100 will be described with reference to fig. 2.

The cross-sectional profile shape of the inner peripheral surface 41 is set as follows. First, as shown in fig. 2, the central axis C is set to the origin O (0, 0) of the xy rectangular coordinate system, and the cross-sectional contour shape of the inner peripheral surface 41 is expressed by the distance r from the origin O in the xy rectangular coordinate system. Here, the x-axis is set as, for example, a straight line connecting the center and the central axis C along the circumferential direction in the closest portion (portion a formed within a predetermined angular range 2 × θ 1) between the inner circumferential surface 41 of the cylinder 40 and the outer circumferential surface 51 of the rotor 50.

The angle around the origin O when going from the positive direction of the x-axis to the positive direction of the y-axis (the direction opposite to the rotation direction R of the rotor 50) is defined as θ. The sectional profile shape in the positive range of the y-axis and the sectional profile shape in the negative range of the y-axis are rotationally symmetric with respect to the origin O.

As shown in fig. 2, a portion a in a predetermined angular range (0 θ [ degrees ] θ 1; θ 1 is an angle smaller than 90[ degrees ], for example, an angle of 10[ degrees ] or less) including a portion intersecting the positive direction of the x-axis (θ is 0) in the cross-sectional contour shape is a closest portion and is formed by an arc (r is P) having a radius P centered on the origin O. Similarly, a portion e in a predetermined angular range (- θ 1 ≦ θ ≦ 0) in which the angle θ is negative with respect to the positive direction of the x-axis is also the closest portion and is formed by an arc (r ═ P) having a radius P centered around the origin O.

since the cross-sectional profile shape in the positive range of the y-axis and the cross-sectional profile shape in the negative range of the y-axis are rotationally symmetrical with respect to the origin O, the portion e in the angular range (90< θ 4 ≦ θ ≦ 180; where θ 4 ≦ 180 — θ 1) that is rotationally symmetrical with respect to the portion e in the predetermined angular range (-90< - θ 1 ≦ θ 0) in which the angle θ is negative with respect to the positive direction of the x-axis is also formed by an arc (r ═ P) of a radius P centered on the origin O.

in the cross-sectional profile shape, the portion b in which the angle θ from the positive direction of the x-axis is in an angular range of the angle θ 1 or more (θ 1 θ 2) is formed by a curve defined by the distance r in the following equation (1), as an example.

r + Qsin2{ S (θ - θ 1) } (where 0< P, 0< Q, 0< S <1) (1)

The curve of the formula (1) is an elliptical formula having a short diameter P and a long diameter P + Q. Since S in equation (1) is a positive number smaller than 1, in the ellipse expressed in equation (1), the minor axis x1 is located at an angle inclined by θ 1 from the positive direction of the x axis only in the positive direction of the y axis (θ is 90 degrees), and the major axis y1 is located at an angle inclined by (θ 1+90/S-90) degrees from the positive direction of the y axis only in the negative direction of the x axis (θ is 180 degrees).

The portion a1 where the minor axis x1 intersects the inner peripheral surface 41 is a part of the aforementioned closest portion, and the portion b1 where the major axis y1 intersects the inner peripheral surface 41 is the farthest portion where the inner peripheral surface 41 of the cylinder 40 is farthest from the outer peripheral surface 51 of the rotor 50. The farthest portion is not formed within a predetermined angular range, unlike the closest portion, but is simply two points symmetrical to each other on the inner peripheral surface 41.

Here, when S <1, the angle (90/S) [ degree ] is larger than the angle 90[ degree ], and therefore the major axis y1 of the ellipse is deviated to an angular position of an angle Δ θ (═ 90/S-90) only in the negative direction of the x axis, that is, on the upstream side (suction stroke side) in the rotation direction R of the rotor 50, as compared with the direction (θ ═ θ 1+90) orthogonal to the angular position (θ ═ θ 1) of the minor axis x1 of the ellipse of formula (1). That is, the major axis y1 is not orthogonal to the minor axis x1, but is offset to the upstream side in the rotational direction R of the rotor 50. Further, the long axis y1 is offset in the negative direction of the x axis, and the farthest portion is formed offset to the upstream side in the rotational direction R of the rotor 50, so that the compression stroke and the discharge stroke are longer than the intake stroke.

The condition of S in formula (1) is not limited to S < 1. That is, in the formula (1), S <90/(90- θ 1) may be used. Even under such conditions, the major axis y1 of the ellipse of equation (1) is formed at an angular position offset to the upstream side (intake stroke side) in the rotation direction R of the rotor 50 in the negative direction of the x-axis, and the farthest part is formed offset to the upstream side in the rotation direction R of the rotor 50, so that the compression stroke and the discharge stroke are longer than the intake stroke.

The ellipse of expression (1) is set so as to smoothly connect to a portion a that forms a circular arc in the angular range (0 ≦ θ 1) at the angular position (θ ≦ θ 1) of the minor axis x1 so that the slopes of the tangents match.

The position where the angle θ 2 is at the end of the portion b in the angular range (θ 1 ≦ θ 2) is set to the angular position of the major axis y1 of the ellipse of expression (1) (θ 2 ≦ θ 1+ 90/S). Therefore, the portion b of the angular range (θ 1 ≦ θ 2) corresponds to the rotation direction R of the rotor 50, and is a cross-sectional profile of the equation (1) and a cross-sectional profile of an angular position (θ ═ θ 1) from the angular position (θ ≦ θ 2) of the major axis y1 toward the angular position (θ ═ θ) of the minor axis x1, and thus is a range in which the volume of the compression chamber 55 is reduced, and corresponds to the compression stroke and the discharge stroke of the compression chamber 55.

In the cross-sectional profile shape, the portion e of the predetermined angular range (θ 4 ≦ θ ≦ 180) from the negative direction of the x-axis toward the positive direction of the y-axis is formed by an arc (r ═ P) of a radius P centered on the origin O as described above. Therefore, the portion e is also the closest portion.

In the cross-sectional profile shape, the portion d in the predetermined angular range (θ 2< θ 3 ≦ θ 4<180) in which the angle θ from the positive direction of the x-axis is equal to or larger than the angle θ 3 of the long axis y1 of the ellipse of equation (1) than the angle position (θ ≦ θ 2) of the negative direction side of the x-axis is formed by a curve (an example of a first curve) defined by the distance r of equation (2) below, as an example.

r ═ P + Tsin2(θ + θ 4) (where Q < T) (2)

The curve of the equation (2) is an equation representing an ellipse having a short diameter P and a long diameter P + T, the short axis x2 of the ellipse is located at an angular position inclined by only an angle θ 1 (180- θ 4) from the negative direction of the x axis (θ 180) to the positive direction of the y axis (θ 90), and the long axis y2 of the ellipse of the equation (2) is located in an angular position inclined by only the angle θ 1(θ 90- θ 1) from the positive direction of the y axis to the positive direction of the x axis. Therefore, the minor axis x2 of the portion d of the angular range (θ 3. ltoreq. θ 4) is orthogonal to the major axis y 2. The portion a2 where the minor axis x2 intersects the inner peripheral surface 41 is a part of the closest portion.

Since T in expression (2) is a positive number greater than Q in expression (1), the major axis (P + T) of the elliptical shape represented by expression (2) is longer than the major axis (P + Q) of the elliptical shape represented by expression (1), but the portion d of the angular range (θ 3 ≦ θ 4) does not include the portion of the major axis y 2.

The portion d of the angular range (θ 3 ≦ θ 4) corresponds to the rotational direction R of the rotor 50, and is a range in which the volume of the compression chamber 55 increases, corresponding to the suction stroke of the compression chamber 55, because it has the cross-sectional profile of equation (2) and the cross-sectional profile from the angular position of the short axis x 2(θ ≦ θ 4) to the angular position of the long axis y 2.

The ellipse of expression (2) is set so as to smoothly connect to a portion e forming a circular arc in the angular range (θ 4 ≦ θ ≦ 180) at the angular position (θ 4) of the minor axis x2 so that the slopes of the tangents match.

In the cross-sectional profile shape, the angle θ from the positive direction of the x-axis is a portion c in a predetermined angular range (θ 2 ≦ θ 3) from the angular position (θ 2) of the major axis y1 of the elliptical portion b of expression (1) to the angular position (θ ≦ θ 3) of the end of the elliptical portion d of expression (2), and is formed by an arc (an example of the second curve). The arc has a center Oc on the major axis y1 of the ellipse of formula (1) forming the portion b of the angular range (theta 1 & lttheta & gttheta & lttheta 2), and is formed by a radius rA (< P + Q).

The arc is set to smoothly connect to the portion b forming the arc of the ellipse of expression (1) so that the slope of the tangent line coincides with the angular position (θ ═ θ 2), and to smoothly connect to the portion d forming the arc of the ellipse of expression (2) so that the slope of the tangent line coincides with the angular position (θ ═ θ 3).

As described above, the cross-sectional profile of the inner peripheral surface 41 shown in fig. 2 is defined by the following (i) to (v).

(i) The portion a of the angular range (0. ltoreq. theta. ltoreq. theta.1) is formed by an arc (r. P) of a radius P centered on the origin O. The portion a is a closest portion as a whole, and includes a portion (a portion at an angular position (θ 1)) intersecting the minor axis x1 of the ellipse of expression (1).

(ii) the portion b of the angular range (θ 1 ≦ θ 2) is formed by an arc shape of a portion b1 intersecting from a portion a1 intersecting the minor axis x1 of the ellipse represented by formula (1) to the major axis y1 formed further toward the upstream side in the rotation direction R of the rotor 50 than the y-axis. At the angular position (θ ═ θ 1), the portion a is smoothly connected.

(iii) The entire portion e of the angular range (θ 4 θ ≦ 180) is the closest portion, and is formed by an arc (r ═ P) of a radius P centered on the origin O. The portion e includes a portion (a portion at an angular position (θ 4)) a2 that intersects a minor axis x2 of an ellipse of formula (2) to be described later.

(iv) The portion C of the angular range (θ 2 θ 3) is formed by an arc (an example of a second curve) having a radius rA of the center Oc on the major axis y1 of the ellipse represented by formula (1) (on a straight line connecting the center axis C and the farthest portion (the portion b1 where the major axis y1 intersects the inner peripheral surface 41). The arc is a curve in which the distance r from the origin O (central axis C) changes, and smoothly connects to the portion b at an angular position (θ ═ θ 2) and smoothly connects to the portion d at an angular position (θ ═ θ 3).

(v) The portion d of the angular range (θ 3. ltoreq. θ 4) is formed by an arc (an example of the first curve) of a portion where the minor axis x2 of the ellipse expressed by the equation (2) intersects. And smoothly connects to the portion e at the angular position (θ 4).

The ellipse of the equation (2) in the portion d of the predetermined angular range (θ 3 θ 4) has a shape in which the tip 58a of the vane 58 is continuously in contact with the inner peripheral surface 41 as the vane 58 flies out of the rotor 50.

As described above, the vane 58 protrudes by receiving the centrifugal force generated by the rotation of the rotor 50 and the hydraulic pressure acting on the back pressure chamber 52. However, if the distance r from the origin O, which is the cross-sectional profile of the inner circumferential surface 41 of the cylinder 40, is a shape that sharply increases with respect to the rotation angle of the rotor 50, the protrusion of the vane 58 cannot sufficiently follow, and the tip 58a of the vane 58 may be separated from the inner circumferential surface 41. In particular, after the start of rotation from a state in which the rotor 50 is stopped, the centrifugal force and the hydraulic pressure acting on the back pressure chamber 52 are small, and therefore the protrusion of the vane 58 is under strict conditions.

Fig. 3 is a graph showing an example of the correspondence relationship between the rotation angle [ degrees ] of the rotor 50 and the projection length [ mm ] of the blade 58 (without restraint of the inner peripheral surface 41) under such severe conditions. The rotation angle of the rotor 50 on the horizontal axis in the graph is set to 0[ degree ] in a state where the tip 58a of the blade 58 coincides with the negative direction of the x-axis shown in fig. 2, and the rotation angle increases in the direction in which the rotation in the rotation direction R proceeds. Therefore, the rotation angle of the rotor 50 in fig. 3 is different from the angle θ shown in fig. 2 in the reference position and the increasing direction.

As shown in fig. 3, when the rotation angle of the rotor 50 is small, that is, when the vane 58 passes through the portion d of the angular range (θ 3 θ 4) of fig. 2 corresponding to the suction stroke, the projection length of the vane 58 is relatively small. Therefore, in the portion d, the tip 58a of the blade 58 tends to be easily separated from the inner peripheral surface 41. Therefore, the formula (2) is set so that the range of r of the formula (2) defining the portion d, that is, the range in which the tip 58a continuously contacts the inner circumferential surface 41 can be followed by the projection length of the blade 58 at the corresponding rotation angle of the rotor 50.

In the compressor 100 of the present embodiment, the cross-sectional contour shape of the inner peripheral surface 41 is an elliptical shape as a whole, and the short diameter (closest portion) having the shortest distance r from the origin O is formed not only in the portion a1 where the minor axis x1 of the elliptical shape defined by the expression (1) intersects with the portion a2 where the minor axis x2 of the elliptical shape defined by the expression (2) intersects, but also in a circular arc state in a predetermined angular range as in the portions a and e. On the other hand, in the compressor 100 of the present embodiment, the major axis (farthest portion) having the longest distance r from the origin O is only the portion (two points in the cross-sectional contour shape) b1 where the major axis y1 of the ellipse defined by equation (1) intersects.

In the cross-sectional profile shape of the inner peripheral surface 41, a portion ranging from the portion a2 at the end of the closest portion to the portion b1 at the farthest portion on the downstream side in the rotation direction R of the rotor 50 is formed as two curved lines including an arc (portion d) and an arc (portion c) of an ellipse of the formula (2).

According to the compressor 100 of the present embodiment configured as described above, it is possible to prevent or suppress over-compression in the compression chamber 55 and prevent the blades 58 from failing to completely follow. That is, by applying the elliptical arc of the formula (1) in which the major axis y1 is biased toward the intake stroke, the portion b corresponding to the compression stroke can be made longer than in the case where the portion b is not biased. When the compression stroke is extended, the volume change speed is relaxed, and the occurrence of over-compression can be suppressed.

when the major axis y1 of the portion b is shifted toward the suction side, if the portions d and c corresponding to the suction stroke are defined by the elliptical arc of the same expression (2) as the portion b, the protrusion of the blade 58 is difficult to follow. However, in the compressor 100 of the present embodiment, the portions d and c corresponding to the intake stroke are defined by the elliptical arcs of the other expression (2) in which the curves are different from the portion b corresponding to the compression stroke, that is, the range that the vane 58 can follow, and therefore, even if the projection of the vane 58 is under severe conditions, the separation of the tip 58a of the vane 58 from the inner circumferential surface 41 of the cylinder 40 can be prevented or suppressed.

Further, when the portions d and c corresponding to the intake stroke are set to the curves different from the portion b corresponding to the compression stroke, the arc of the ellipse of the expression (2) of the intake stroke and the arc of the ellipse of the expression (1) of the compression stroke are not smoothly connected or are difficult to smoothly connect. However, in the compressor 100 of the present embodiment, regarding the portions d and c corresponding to the intake stroke, the portion d on the side close to the short diameter is set to the arc of the ellipse of the other expression (2) in the range that the vane 58 can follow, and the portion c on the side close to the long diameter (portion b) is set to the arc of the example of the other curve (second curve) smoothly connected to the arc of the ellipse of the expression (2) and the arc of the ellipse of the expression (1), respectively, whereby the following performance of the vane 58 can be ensured, and the rapid operational change of the vane 58 can be prevented or suppressed.

In addition, according to the compressor 100 of the present embodiment, since the distances r from the origin O of the portions b and c in the cross-sectional profile of the inner peripheral surface 41 vary depending on the angle θ and only the portion b1 connected to the long axis y1 becomes the farthest portion, the portion where the tip 58a of the vane 58 contacts moves in a certain angular range including the long axis y1 regardless of the angle θ, as compared to the case where the distance r from the origin O is constant, and there is an effect of suppressing the accelerated wear due to the constant continuous contact of the constant portion.

Further, since the center Oc of the circular arc in the portion c is located on the major axis y1, the portion b and the portion c connected to the major axis y1 are smoothly connected to each other, and the radius rA of the circular arc is adjusted, whereby adjustment for smoothly connecting to the portion d is facilitated. Further, the radius rA of the circular arc in the portion c is shorter than the major axis (P + Q) of the major axis y1 (portion b), and therefore, the projection length of the blade 58 at the portion c can be prevented or suppressed from increasing sharply.

In addition, according to the compressor 100 of the present embodiment, the arc of the ellipse of the expression (2), which is one example of the first curve corresponding to the portion d of the suction stroke, is formed by the arc of another ellipse different from the ellipse of the expression (1), which forms the cross-sectional profile shape from the major axis y1 to the minor axis x1 toward the downstream side in the rotation direction R of the rotor 50, and therefore, the inner circumferential surface 41 having a shape in which the tip 58a of the vane 58 in the portion d is difficult to separate is easily selected.

In the compressor 100 of the present embodiment, an elliptical arc is applied as a first curve and an arc is applied as a second curve with respect to the cross-sectional profile shape of the inner circumferential surface 41 of the cylinder 40, but the gas compressor of the present invention is not limited to this embodiment. That is, in the contour shape of the inner peripheral surface of the cylinder in the present invention, the first curve may be a curve other than an arc of an ellipse which protrudes outward, and the second curve may be a curve other than an arc which protrudes outward.

Specifically, the curve forming the portion B of the cross-sectional profile shape from the farthest portion B1 to the closest portion a1 corresponding to the compression stroke and the discharge stroke is defined by a specific first elliptical expression (for example, an expression in which constants B1 and B2 are set to appropriate values in the following expression (3)) having the farthest portion B1 as the major diameter and the closest portion a1 as the minor diameter.

r is a + B1 × sinn { B2 × (θ - θ 1) } (where θ 1 may be 0 (zero)) (3)

At this time, the first curve may be a curve formed inside (short in size from the central axis C) the cylinder chambers 53 and 54 in the portion d as a curve defined by a specific second elliptical equation (for example, the following equation (4)) having the closest portion a2 as a short diameter and the farthest portion b1 as a long diameter, and smoothly connecting the curve defined by the specific first elliptical equation (3)) from the closest portion a2 to the farthest portion b1 corresponding to the intake stroke in the farthest portion b 1.

r is a + B1 × sinn { B3 × (θ -180+ θ 1) } (where θ 1 may be 0 (zero)) (4)

That is, in the case where the constant B1 in the elliptical equation (4) corresponding to the first curve is larger than the constant B1 in the specific second elliptical equation (4) and the constant B3 in the elliptical equation (4) corresponding to the first curve is larger than the constant B3 in the specific second elliptical equation (4) when the first curve is defined in the specific second elliptical equation (4), the first curve is formed inside the cylinder chambers 53, 54 in the portion d as compared with the curve defined by the specific second elliptical equation (4), and may be a curve closer to the graph shown in fig. 3.

In addition, in the case where the constant B1 in the elliptical equation (4) corresponding to the first curve is smaller than the constant B1 in the specific second elliptical equation (4) and the constant B3 in the elliptical equation (4) corresponding to the first curve is smaller than the constant B3 in the specific second elliptical equation (4) when the first curve is defined by the specific second elliptical equation (4), the first curve is also formed inside the cylinder chambers 53, 54 in the portion d as compared with the curve defined by the specific second elliptical equation (4), and can be closer to the curve of the graph shown in fig. 3.

As the second curve, in addition to the circular arc, for example, a cubic bezier curve protruding outward or a curve defined by a cubic equation can be applied.

in the compressor 100 of the present embodiment, the sectional contour shape of the portion of the angular range from the closest portion to the farthest portion on the downstream side in the rotation direction R of the rotor 50 is formed by two curves different from each other, but in the gas compressor of the present invention, the sectional contour shape of the portion of the angular range is not limited to being formed by 2 curves, and may be formed by 3 curves, or may be formed by 4 or more curves. However, if the inner peripheral surface 41 is formed of a plurality of curved surfaces, the manufacturing labor increases, and therefore, from the viewpoint of manufacturing cost, a small number is preferable.

in the compressor 100 of the present embodiment, the cross-sectional profile shape of the portion (compression stroke and discharge stroke) in the angular range from the farthest portion to the closest portion on the downstream side in the rotation direction R of the rotor 50 is formed by a single ellipse, but the cross-sectional profile shape of the portion in the angular range in the gas compressor of the present invention is not limited to this embodiment, and may be formed by 2 or more curves.

Cross reference to related applications

The present application claims priority based on the application of patent application No. 2017-.