JPH036356B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides a rotor having a plurality of retractable vanes arranged eccentrically within a rotating sleeve, and synchronously rotating the rotor and the rotating sleeve. The present invention relates to a rotary compressor with a rotary sleeve that compresses air by sequentially changing the volume of an air chamber partitioned by each vane.

(Prior Art) This type of rotary compressor with a rotary sleeve has a casing constructed by attaching side housings 52 and 53 to both sides of a center housing 51 having a cylindrical inner peripheral surface 51a, as shown in FIG. A cylindrical rotating sleeve 55 is rotatably fitted into the rotating sleeve 50 .
A rotor 58 in which a plate-shaped vane 56 is removably fitted in a slit-shaped vane groove 57 formed in the radial direction is arranged eccentrically within the rotor 58, and the frictional force between the vane and the rotating sleeve 55 is reduced. The rotor 58 and the rotating sleeve 55 are rotated synchronously to fluidly change the volume of the air chamber 59 surrounded by the rotating sleeve 55, the rotor 58, and the vane 56, thereby sucking air. It is configured to perform compression and discharge actions.

In this case, the compressed air discharge port 54
is usually formed only on one of the two side housings (the side housing 52 in the case shown in Fig. 6) (the suction port is also formed on the side housing on the same side as the discharge port). (often).

However, if the discharge port 54 is formed only in one side housing 52 of the two side housings, as will be described in detail later, the vane 56 will wear unevenly in a tapered shape in the longitudinal direction, and the rotating sleeve 55 and center housing 51
between each other and the vane 56 and the side housing 52,
Seizing occurs between the vanes 53 and the vanes 56
This results in the problem that pitching is likely to occur.

That is, when the vane 56 moves upward and downward within the vane groove 57 as the rotor 58 rotates, the pump is pumped in the bottom cavity S of the vane groove 57 by the lower surface 56b of the vane 56. action is taken. At this time, pressurized air flows out to the discharge port 54 side due to the pumping action of the vane 56, but the void portion S 2 located far from the discharge port 54 in the vane groove bottom void S ₂ In this case, the pressurized air cannot flow out smoothly, and therefore, in the hollow part _S2 , there is always another hollow part (the hollow part near the discharge port 54).
S ₁ ). That is, there is always P between the air pressure (vane back pressure) P ₁ in the cavity part S ₁ on the side close to the discharge port 54 and the vane back pressure P ₂ in the cavity part S ₂ on the side far from the discharge port 54. The relationship ₁ < P ₂ occurs (unequal vane back pressure). Therefore, due to the unevenness of the vane back pressure, the contact pressure between the vane 56 and the rotating sleeve 55 is higher on the side opposite to the discharge port 56B than on the side opposite to the discharge port 56B.
6A side (uneven contact pressure), and during long-term use, the vane 56 gradually becomes unevenly worn in a tapered shape in the longitudinal direction as shown by the chain line (reference numeral 56').

Therefore, the longitudinal end surface 56c of the vane 56,
56d is lower than that of each side housing 52, 53 than in the normal state where uneven wear has not occurred on the vane 56.
When the vane end faces 56c, 56d come into contact with the side housings 52, 53, seizure occurs between them, and the vane 56 protrudes from the side housings 52, 53 at its protruding corner. A problem arises in that the vane 56 causes pitting due to point contact.

Furthermore, as mentioned above, the fact that the air cannot flow out smoothly in the bottom cavity S of the vane groove means that the retracting movement of the vane 56 is inhibited and the contact pressure of the vane 56 against the rotating sleeve 55 is increased. As a result, as the rotor 58 rotates, the rotating sleeve 55 is gradually pressed from its normal rotational position to the compression side wall surface of the center housing 51 and comes into strong contact with the wall surface of the center housing 51, resulting in seizure between the two. Become.

Furthermore, although this is generally the case in a rotary compressor configured such that the lower surface 56b of the vane 56 performs a pumping action in the bottom cavity S of the vane groove 57, for example, the pumping action of a specific vane may If pressurized air flows into the suction port side, the suction efficiency of the rotary compressor will be reduced.

In other words, the air pressurized by the pumping action of the vanes is heated by the compression action of the rotary compressor, and then further raised by the pumping action of the vanes, resulting in a considerably high temperature and a large volumetric expansion. . Therefore, when such high-temperature and volume-expanding air flows into the intake port side, the volume expansion of this inflow air itself and
Due to the synergistic effect with the volumetric expansion of the original intake air, which is heated by contact with the incoming air, the intake efficiency as a rotary compressor is substantially reduced. Therefore, when taking countermeasures against the pumping effect of the vanes, it is necessary to fully consider the problem of a decrease in suction efficiency.
The reason why the air pressurized by the pumping action of the vanes in the empty space on the discharge port side easily flows into the air chamber on the suction port side is because the air chamber on the discharge port side has a high internal pressure, but the air chamber on the suction port side has a high internal pressure. The internal pressure of the side air chamber is low, and therefore the pressurized air in the space located on the discharge port side flows into the air chamber on the suction port side more easily than the air chamber on the discharge port side.

(Object of the Invention) In view of the problems pointed out in the above-mentioned section of the prior art, the present invention aims to solve the problem of increasing the back pressure of the vanes moving in and out of the vane grooves of the rotor without causing a decrease in the suction efficiency of the rotary compressor. While suppressing the back pressure, the back pressure is made as equal as possible over the entire length of the vane in the longitudinal direction, thereby preventing seizure and vane pitting between the vane and the side housing and between the rotating sleeve and the center housing. This is intended to improve the durability of the compressor as a whole.

(Means for Achieving the Object) The present invention provides, as a means for achieving the above object, an inner surface of a pair of side housings constituting a casing that does not have a discharge port, and a position in the rotational direction of the rotor. At a position corresponding to the discharge port, a buffer chamber is formed that can communicate with the space formed by the vane groove and the lower surface of the vane of the rotor, and the pumping volume on the side opposite to the discharge port is increased by the buffer chamber. This is intended to suppress the increase in vane back pressure itself, as well as to suppress unevenness in vane back pressure between the discharge port side position and the opposite position to the discharge port side.

(Function) In the present invention, the above means suppresses the increase in vane back pressure itself, and equalizes the vane back pressure as much as possible over the longitudinal direction of the vane regardless of the distance from the discharge port. This prevents tapered uneven wear in the longitudinal direction of the vane, thereby preventing seizure between the vane and the side housing and pitting of the vane, and further reducing the contact pressure between the vane and the rotating sleeve. This also prevents seizure between the rotating sleeve and the center housing since the radial displacement of the rotating sleeve is reduced.

Further, the buffer chamber can communicate with the cavity formed by the vane groove and the lower surface of the vane of the rotor on the inner surface of the side housing on the side opposite to the discharge port and at a position corresponding to the discharge port in the rotational direction of the rotor. Because of this, pressurized air due to the pumping action of the vane flows into the cavity of the other vane located on the suction port side through the buffer chamber, and from the cavity, the vane and the vane groove. This prevents the water from flowing into the suction port side through the gap between the two.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS. 1 to 3.

(a: Configuration) FIG. 1 shows a rotary compressor Z ₁ according to an embodiment of the present invention.
It is shown. This rotary compressor _Z1 is used as a supercharger for an automobile engine, and is fastened to a center housing 2 having a cylindrical inner peripheral surface 2a and both ends of the center housing 2. A pair of side housings, that is, a first side housing 3 in which a suction port (not shown) and a discharge port 15 are formed at appropriate intervals in the circumferential direction.
and a casing 1 consisting of a second side housing 4 having no suction port or discharge port.

A cylindrical rotating sleeve 5 and a rotor 6, which will be described later, are fitted into the casing 1.

The rotating sleeve 5 is attached to the center housing 2
It has an outer diameter smaller than the inner diameter dimension by an appropriate dimension, and when it is rotatably fitted concentrically in the casing 1, the inner circumferential surface 2a of the casing 1 and the outer circumferential surface 5a of the rotary sleeve 5 An air bearing chamber 14 of an appropriate size is formed between the two. The air bearing chamber 14 is connected to the first side housing 3 through an air passage 16 consisting of an air chamber 16a and an air chamber 16b formed in the center housing 2, and a communication passage 16c formed in the first side housing 3. The rotary sleeve 5 is connected to the discharge port 15, and the rotary sleeve 5 is rotatably supported in a floating state by pressurized air introduced into the air bearing chamber 14 (air bearing action).

The rotor 6 has a rotor body 11 integrally formed with a hollow cylindrical body, and a rotor shaft 10 formed at its axial center is connected to the first side housing 3 and the second side housing 3.
They are each rotatably supported by the side housing 4 and are eccentrically arranged within the rotating sleeve 5 (see FIG. 3). This rotor 6
The rotor body 11 has a vane groove 1 of an appropriate depth extending in the radial direction as shown in FIGS. 1 and 3.
2, 12... are formed at equal intervals in the circumferential direction. In each of the vane grooves 12, 12..., plate-shaped vanes 7, 7... are fitted so as to be freely retractable. When the rotor 6 rotates, each of the vanes 7, 7, .
1 and 4 air chambers divided in the circumferential direction between 1 and 1.
7A, 17B, 17C, and 17D are formed.

On the other hand, the inner surface 4a of the second side housing 4
As shown in FIGS. 1 and 2, there is formed a buffer chamber 8 consisting of a substantially fan-shaped recess of a suitable depth (in this embodiment, the depth is about 5 mm). The formation position and size of this buffer chamber 8 are determined for each vane 7,
7... sequentially reach the discharge port 15 side, each vane groove 1 corresponding to each vane 7, 7...
The bottom cavities 19 of 2, 12, . . . (that is, the portion of the vane groove 12 closer to the groove bottom than the vane bottom 7b) are appropriately set so as to successively communicate with the buffer chamber 8. That is, in this embodiment, the radius r(θ) of the outer periphery of the buffer chamber 8 is defined as r(θ)=(R ² −a ²・sin θ)−a・cos θ−H, where R: sleeve radius, a: Rotor eccentricity,
H: vane height, θ: rotor rotation angle. Radius r (θ) of the outer periphery of the buffer chamber 8
is set as above, the axial end face of each vane 7, 7... is always non-overlapping with this buffer chamber 8 (in other words, the buffer chamber 8 is connected to each vane groove 12, 1).
Polymerization communication is made only to the bottom cavities 19, 19... of 2...).

Furthermore, the angular range α of the rotor rotation direction of the buffer chamber 8
is a rotational region (i.e.,
Set the angle within 180° within the discharge zone). Therefore, the bottom cavity 19 of the vane groove 12 within the predetermined rotation angle (angle α) within the discharge zone is necessarily communicated with the buffer chamber 8.

In addition, in FIGS. 1 and 2, reference numeral 9 designates a carbon ring embedded and fixed in the side housings 3 and 4.

(-b: Operation and Effect) Next, to briefly explain the operation and effect of the rotary compressor _Z1 , when the rotor 6 is rotated by an engine or a motor, each vane groove 12 of the rotor 6 , 12... each vane 7,
7 project outward due to centrifugal force, and their upper surfaces 7a, 7a... contact the inner surface 5b of the rotating sleeve 5, so that the rotating sleeve 5 pulls the respective vanes 7, 7... by the frictional force between them. The rotor 6 is rotated synchronously with the rotor 6 through the rotor 6. As the rotor 6 and rotating sleeve 5, which are eccentrically arranged relative to each other, rotate synchronously via the vanes 7, 7..., the volume of each air chamber 17A, 17A... is sequentially changed, and the suction port ( (not shown) is pressurized and discharged from the discharge port 15. At this time, a part of the discharged air is introduced into the air bearing chamber 14 of the casing 1 through the air passage 16, and the rotating sleeve 5 is kept in a non-contact state with the inner circumferential surface 2a of the center housing 2 due to the air bearing action. It can be rotated at high speed while being held.

On the other hand, as the rotor 6 rotates, each vane 7, 7
... respectively protrude and retract within the respective vane grooves 12, 12..., and a pumping action occurs on the lower surface 7b side of each of the vanes 7, 7.... At this time, especially in the discharge zone where the vane groove 12 overlaps the discharge port 15, as explained in the prior art section, the upper surface 7a of the vane 7 is bent in the longitudinal direction due to the imbalance in the vane back pressure of the vane 7. There is a risk of uneven wear in a tapered shape.

However, in this embodiment, by applying the present invention, a buffer chamber 8 that communicates with the bottom cavity 19 of the vane groove 12 in the discharge zone is provided on the inner surface 4a of the second side housing 4 which does not have the discharge port 15. As a result, the pumping volume increases on the side opposite to the discharge port 15 by the volume of the buffer chamber 8, which suppresses the increase in vane back pressure and also increases the volume on the side opposite to the discharge port 15 during pumping action. The unevenness of the vane back pressure between the sides is reduced as much as possible compared to the case where such a buffer chamber 8 is not provided,
Tapered uneven wear in the longitudinal direction of the vanes 7 due to uneven vane back pressure is suppressed as much as possible. Incidentally, the uneven wear state of the vane 7 in the case of this example is shown by curve _L2 in Fig. 5, but according to this figure, the one of this example has a conventional structure (the one shown by curve _L1) . ), it can be seen that the uneven wear of the vanes 7 is significantly reduced.

Further, a buffer chamber 8 is formed on the inner surface 4a of the second side housing 4 on the side opposite to the discharge port and at a position corresponding to the discharge port 15 in the rotational direction of the rotor 6, so as to be able to communicate with the bottom cavity 19 of the vane 7. Because of this, the air pressurized by the pumping action of the vane 7 on the discharge port side flows into the bottom cavity 1.
9 through the buffer chamber 8 into the bottom cavity 19 of the vane on the suction port side.
9 to the suction port side through the space between the vane 7 and the vane groove 12. Therefore, it is possible to prevent the suction efficiency of the rotary compressor from decreasing due to the volumetric expansion of the inflowing air itself and the volumetric expansion of the normal intake air whose temperature is raised by the temperature of the inflowing air. It is.

(Effects of the Invention) The present invention provides a casing having a center housing having a cylindrical inner peripheral surface and a pair of side housings disposed on both sides of the center housing, and one of the pair of side housings. A discharge port formed in the side housing, a rotating sleeve rotatably fitted in the center housing, a rotor eccentrically arranged in the rotating sleeve, and a vane groove provided in the radial direction of the rotor. In a rotary compressor equipped with a plurality of vanes that are retractably fitted and in sliding contact with the inner circumferential surface of the rotary sleeve, the rotation of the rotor is performed on the inner surface of the side housing of the pair of side housings that does not have a discharge port. The present invention is characterized in that a buffer chamber is formed at a position corresponding to the discharge port in the directional position, which can communicate with the cavity formed by the vane groove and the lower surface of the vane of the rotor.

Therefore, according to the present invention, the increase in vane back pressure on the discharge zone side is suppressed and the contact pressure between the vane and the rotating sleeve is maintained appropriately, so that the contact pressure between the rotating sleeve and the center due to misalignment of the rotating sleeve is suppressed. This has the effect of suppressing contact with the housing as much as possible, and preventing seizure between the rotating sleeve and the center housing.

Furthermore, since tapered uneven wear in the longitudinal direction of the vane is suppressed as much as possible by equalizing the back pressure of the vane, contact between the longitudinal end surface of the vane and the inner surface of the side housing is prevented as much as possible. As a result, seizure between the vane and the side housing and pitting of the vane can be prevented.

In addition, the buffer chamber is formed on the inner surface of the side housing on the side opposite to the discharge port so that it can communicate with the cavity formed by the vane groove of the rotor and the lower surface of the vane. Air flows through the buffer chamber into the cavity of the vane on the other suction port side located on the suction port side, and from the cavity flows into the suction port side through the space between the vane and the vane groove, This prevents the suction efficiency of the rotary compressor from decreasing due to the volumetric expansion of the incoming air itself and the volumetric expansion of the regular intake air whose temperature is raised by the temperature of the incoming air, resulting in a high level of suction efficiency. It also has the effect of maintaining the

[Brief explanation of the drawing]

FIG. 1 is a sectional view of essential parts of a rotary compressor according to an embodiment of the present invention, FIG. 2 is a view of the second side housing shown in FIG. - Arrow view of rotor and rotating sleeve, 4th
The figure is a vertical sectional view of the main part of a rotary compressor with a conventional structure.
The figure is a comparison diagram of vane wear in the rotary compressor according to the embodiment of the present invention shown in FIG. 1 and the conventional rotary compressor shown in FIG. 4. 1... Casing, 2... Center housing, 3, 4... Side housing, 5... Rotating sleeve, 6... Rotor, 7... Vane, 8, 38
... Buffer chamber, 10 ... Rotor shaft, 12 ... Vane groove, 15 ... Discharge port.

Claims (1)

[Claims] 1. A casing having a center housing having a cylindrical inner circumferential surface and a pair of side housings disposed on both sides of the center housing;
A discharge port formed in one of the pair of side housings;
A rotary sleeve rotatably fitted in the center housing, a rotor eccentrically arranged within the rotary sleeve, and a rotor fitted in a vane groove provided in the radial direction of the rotor so as to be retractable, and a rotor sleeve rotatably fitted in the center housing; A rotary compressor equipped with a plurality of vanes in sliding contact with a surface, the inner surface of the side housing which does not have a discharge port among the pair of side housings, and a position corresponding to the discharge port in the rotational direction of the rotor. A rotary compressor, characterized in that a buffer chamber that can communicate with the cavity formed by the vane groove and the lower surface of the vane of the rotor is formed.