Scroll type compressor having curved surface portions between the shaft and bearing means

Abstract

A scroll type compressor comprising: a crankshaft having an eccentric shaft portion formed thereon; an orbiting scroll which is given torque by the crankshaft through the eccentric shaft portion; and bearing means for rotatably supporting the crankshaft; wherein at least one of the eccentric shaft portion and the bearing means is constituted by a rotatably engaged bushing and a curved surface portion.

Description

BACKGROUND OF THE INVENTIONThe present invention relates to a scroll type compressor, and more particularly to a scroll type compressor which is utilized in refrigeration and air conditioning systems.A conventional scroll type compressor, which has been disclosed in e.g. Japanese Unexamined Patent Publication No. 80088 / 1988, is constructed as shown in FIG. 17. In FIG. 17, reference numeral 1 designates a fixed scroll. Reference numeral 2 designates an orbiting scroll. Reference numeral 3 designates a crankshaft. Reference numeral 4 designates a driving bushing which is rotatably mounted in a bearing part 2a formed in the orbiting scroll 2. Reference numeral 5 designates an Oldham's ring. Reference numeral 6 designates a main frame. Reference numeral 6a designates a main bearing which is formed in the main frame 6. Reference numeral 7 designates an electric motor stator. Reference numeral 8 designates an electric motor rotor. Reference numeral 9 designates a sub frame. Reference nume...

AI Technical Summary

Benefits of technology

It is an object of the present invention to solve the problem, and to provide a ,highly reliable scroll type compressor capable of preventing a bearing part from being damaged due to wear, seize or the like even if a crankshaft is flexture-deformed by a radial direction force in compressive loads which are exerted to an orbiting scroll during a compression stroke.

In the scroll type compressor according to the present invention, a radial direction force is exerted on the orbiting scroll during a compression stroke, and the force is applied to the eccentric shaft portion which is provided on top of the crankshaft. As a result, the crankshaft is subject to flexture-deformation. In accordance with the present invention, the scroll type compressor is provided with such bearing means that the eccentric shaft portion, the main shaft portion or the sub shaft portion of the crankshaft has a curved surface, or has a central portion provided with a barrel shaped band portion to present a convex surface in the entire peripheral direction. The curved surface or the band portion allows a driving bushing or a cylindrical bushing to be in touch with the curved surface or the barrel shaped surface so as to be axially rotatable and movable. Such an arrangement can drive the crankshaft in a parallel state with respect to each bearing. As a result, partial contact can be prevented from bringing about in each bearing, thereby avoiding occurrence of wear and seize. In addition, a bearing load capacity can be prevented from deteriorating, providing a highly reliable scroll type compressor capable of preventing a bearing from being damaged.

Problems solved by technology

This creates e.g. a problem in that load carrying capacities of the respective bearing parts can deteriorate to wear or seize the bearing parts.

In a low speed operating area, an oil film is difficult to be formed in the bearings.

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