JPH0763177A - Scroll compressor - Google Patents

Abstract

PURPOSE:To reduce a discharge resistance due to a discharge port so as to improve efficiency when compressed gas flows out from the inside of a compression chamber by turning motion of a turning scroll in a scroll compressor. CONSTITUTION:A straight line, which passes the center 0 of a base circle of a fixed scroll and is drawn according to an involute angle, is drawn to find intersections with the base circle, and tangents are drawn on these intersections to find intersections S, L between the tangents and the inside and the outside involute curves of a lap 4b. The intersections S, L form a circular arc inside the lap 4b setting a point OL, from which the intersections S, L are positioned in the equal distance to each other on the tangent on the farther side from the lap 4, as the center and setting the distance between the central point OL and the intersection L as a radius. Then, a discharge port is formed on an end plate while being in contact with the circular arc by using the same central point and the same radius as the circular arc. In this way, the circular arc inside the lap 4b and the outer circumference of the discharge port are positioned outside beyond the inside involute curve in the tip part of the lap 4b, so that the area of the discharge port is increased greater than that of a conventional one.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor, and more particularly to reduction of discharge resistance after finishing a final compression step of a refrigerant gas.

[0002]

2. Description of the Related Art FIG. 1 shows a conventional scroll compressor.
The configuration is as shown in. That is, in the scroll compressor, the scroll compressor 2 and the motor 3 are built in the sealed container 1. The scroll compression unit 2 includes a fixed scroll 4, an orbiting scroll 5, a rotation preventing device 6, a crank shaft 7, a crank bearing 8, a frame 9, and a metal bearing 10.
And the shaft 11. In this structure, the fixed scroll 4 fixed to the frame 9 is provided with a spiral wrap 4b provided upright on the end plate 4a, and the wrap 4b is formed of an involute curve or a curve close thereto. On the other hand, the orbiting scroll 5
A spiral wrap 5b is provided upright on the end plate 5a. The shapes of the wraps 4b, 5b of the fixed scroll 4 and the orbiting scroll 5 are in a mirror-mirror-symmetrical relationship with each other, and their angles are deviated by 180 °. Further, the fixed scroll 4 and the orbiting scroll 5 are meshed with each other with the centers of the respective spirals displaced by the orbiting radius, and the two wraps 4b and 5b contact at a plurality of points, so that a plurality of compression chambers 12 are formed.
Is formed. When the shaft 11 is rotated by the rotation of the motor 3, the orbiting scroll 5 in which the crankshaft 7 is inserted into the crank bearing 8 eccentrically provided at the upper end of the shaft 11 does not rotate by the rotation preventing device 6 and does not rotate. 4. Make a turning motion with respect to 4. Due to this swirling motion, the compression chamber 12 is sequentially moved from the outer peripheral portion to the central portion,
The volume of the taken-in refrigerant gas is reduced to cause a compression action, and the compressed refrigerant gas is discharged from the discharge port 13 into the sealed container 1.

Here, the formation of the wrap tip of the scroll compression portion 2 and the formation of the discharge port 13 of the fixed scroll 4 in the conventional example will be described with reference to FIG. The shape of the wrap tips must be such that they do not touch each other, have a small top clearance, and can withstand high pressure. First, a line having a given extension angle φS is drawn through the center O of the basic circle, and a tangent line is drawn at each intersection with the basic circle. Inside the intersection S closest to the starting point of the lap side tangent and the involute curve on the outside of the lap, a point OS on the tangent that is separated by the arc radius of the wrap tip, and a tangent on the side away from the lap and the involute curve on the inside of the lap. The intersection point L closest to the starting point is calculated. Next, a line is drawn from the point OS through the center of the basic circle, and the intersection point OL is obtained on the tangent line on the side away from the lap. With this intersection as the center, a radius is set to the distance to the intersection OL to form an arc following the involute curve. The arc of the wrap tip is formed so as to contact the involute curve outside the lap and the arc inside the wrap center point OS to complete the shape of the wrap tip. As another embodiment, as shown in FIG. 4, in the shape of the wrap tip formed based on FIG. 3, the center point OS of the arc radius of the wrap tip is moved tangentially in the direction in which the arc radius becomes smaller. To form a small arc, and connect it with a common tangent to the arc formed subsequently to the inner involute curve to form the shape of the wrap tip.

Next, the discharge port 13 of the fixed scroll 4
Is the opening of the discharge port 13 which is a circle drawn with a radius smaller than the radius of the arc of the wrap from the center OL of the arc of the wrap on the tangent line on the side away from the lap through the center O of the basic circle. . By the orbiting motion of the orbiting scroll 5, the wrap 5b of the orbiting scroll 5 and the wrap 4 of the fixed scroll 4 are
When compressed gas flows out of the compression chamber formed in b through the discharge port into the high pressure chamber, if the discharge port is small, the discharge resistance of the compressed gas increases and the efficiency of the scroll compressor decreases.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention changes the shape of the wrap tips of fixed and orbiting scrolls to improve the efficiency of the scroll compressor, thereby improving the efficiency of the scroll compressor. It is an object of the present invention to provide a scroll compressor having an enlarged opening area.

[0006]

DISCLOSURE OF THE INVENTION The present invention comprises a pair of compression chambers formed by engaging a fixed scroll and a orbiting scroll in which a spiral wrap is erected on a mirror plate, and a pair of compression chambers.
In the structure in which the discharge port is formed in the central portion of the fixed scroll, the shape of the tip of each scroll passes through the center of the base circle and is tangential to the intersection with the base circle drawn by a straight line by the expansion angle. The intersection point S between the tangent line on the side away from the lap and the inner involute curve of the lap, and the intersection point L on the tangent line on the side closer to the lap with the outer involute curve of the lap are Centering on a point OL that is equidistant on the tangent on the side away from the center, the distance between the center point OL and the intersection L on the inner involute curve of the tangent is a radius RL from L to S inside the lap. An arc is formed, and the discharge port has the same center point OL and radius R as the arc on the end plate of the fixed scroll.
It is characterized in that it is formed of L.

[0007]

According to the present invention, the tangent line drawn through the center of the basic circle of the fixed scroll and the intersection point with the basic circle drawn by a straight line according to the expansion angle, the intersection point with the inner involute curve of the wrap, and the wrap The point of intersection with the outer involute curve of is centered on the point that is equidistant on the tangent on the side away from the lap, and the distance between the center point and the point of intersection with the inner involute curve is the radius and is formed inside the lap. The arc is outside the inner involute curve. Therefore,
The discharge port formed on the end plate with the same center point and the same radius as the circular arc is significantly larger than the opening area of the conventional discharge port.

[0008]

EXAMPLE An example of the present invention will be described below. The present embodiment is the same as the conventional example shown in FIG. 1 except for the shapes of the fixed scroll and the orbiting scroll, and therefore the description of the overall configuration is omitted. The same numbers are used for the same components. The formation of the tooth-shaped starting portions of the wraps 4b and 5b and the formation of the discharge port 13 of the fixed scroll 4 of this embodiment will be described mainly with reference to FIG. A line is drawn through the center O of the basic circle of the fixed scroll 4 at a given expansion angle φS, and a tangent line is drawn at each intersection with the basic circle. An intersection point S between the tangent line extending from the lap side of the base circle and the involute curve outside the lap, and an intersection point L of the tangent line extending from the intersection point distant from the lap through the center O of the base circle and the involute curve inside the lap. Ask for. A point OL having an equal distance from the intersection S and the intersection L is obtained on the tangent line from the intersection on the side away from the wrap of the basic circle. With the point OL as the center and the length from the center point OL to the intersection L as the radius,
The shape of the wrap tip is completed by forming an arc from the intersection L to the intersection S following the involute curve inside the lap. Next, the end plate 4a of the fixed scroll 4 is formed with the point OL as the center and the length from the center point OL to the intersection L as a radius, and the opening of the discharge port 13 in contact with the arc inside the wrap.

[0009]

As described above, according to the present invention,
According to the present invention, passing through the center of the base circle of the fixed scroll, tangent lines drawn respectively at the intersections with the base circle drawn by a straight line due to the expansion angle, and the closest intersection point of the inner and outer involute curves of the wrap. An arc formed inside the wrap with a radius of the distance between the center point OL and the intersection L with respect to the point OL where S and L are equidistant on the tangent on the side distant from the lap is the inner involute curve. More outside. Therefore, the discharge port formed on the end plate with the same center point and radius as the same arc is significantly larger than the opening area of the conventional discharge port, and discharge resistance can be reduced, which improves the efficiency of the scroll compressor. Contribute.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a schematic configuration of a scroll compressor.

FIG. 2 is a plan view showing the shape of the tip of the wrap of the fixed scroll according to the present embodiment.

FIG. 3 is a plan view showing a shape of a wrap tip of a fixed scroll according to a conventional example.

FIG. 4 is a plan view showing the shape of a wrap tip of a fixed scroll according to another conventional example.

[Explanation of symbols]

 1 Sealed Container 2 Scroll Compressor 3 Motor 4 Fixed Scroll 4a Fixed Scroll End Plate 4b Fixed Scroll Wrap 5 Orbiting Scroll 5a Orbiting Scroll End Plate 5b Orbiting Scroll Wrap 9 Frame 11 Shaft 12 Compression Chamber 13 Discharge Port

Claims (1)

[Claims] 1. A pair of compression chambers and a discharge port are formed in the center of the fixed scroll by meshing a fixed scroll and an orbiting scroll in which a spiral wrap is erected on an end plate. In that, the shape of the wrap tip of each scroll passes through the center of the basic circle, draws a tangent line at the intersection with the basic circle drawn by a straight line by the expansion angle, and the side away from the lap. The intersection point S between the tangent line and the inner involute curve of the lap and the intersection point L of the outer involute curve of the lap on the tangent line on the side closer to the lap are equidistant on the tangent line on the side distant from the lap. Centered on the point OL
An arc is formed from L to S inside the wrap with a distance RL between the intersection L on the inner involute curve of the tangent line and a radius RL, and the discharge port has the same center point OL as the arc on the end plate of the fixed scroll. And a radius RL.