JPS63272977A - Crankshaft - Google Patents

Abstract

PURPOSE:To easily produced a light weight crankshaft by forming a shaft body and crank portion respectively of pipe materials while interconnecting both these members through a balance weight for making respective ends thereof eccentric and communicate to each other. CONSTITUTION:A crankshaft used for a reciprocating type compressor or the like is provided on one end of a shaft body 21 with a crank portion 20 through a balance weight 22. Then, the shaft body 21 and the crank portion 20 are formed of pipe materials such as steel pipe respectively. And the respective ends of shaft body 21 and the crank portion 20 are interconnected through the balance weight 22 with the respective bores 23, 24 communicating to each other eccentrically. Thus the balance weight 22 is formed of a circular flat plate made of steel plate or the like provided with a plurality of fitting holes 25, 26 fitting to the respective ends of shaft body 21 and the crank portion 20 and overlapping each other. Thus, the cut working of castings is dispensed with.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a crankshaft with an improved crankshaft assembly structure.

(Prior art) No. 3 showing a reciprocating compressor used in air conditioners, etc.
In the figure, reference numeral 1 denotes a closed case, inside which a crankshaft 2 is rotatably mounted via a bearing 3. A rotor 5 surrounded by a stator 4 constituting an electric element is fitted into the crankshaft 2.

A balance weight 6 is attached to one end of this crankshaft 2.
A crank portion 7 is formed through the crank portion 7, and a rod 10 of a piston 9 that reciprocates within a cylinder 8 constituting a compression element is connected to the crank portion 7.

(Problems to be Solved by the Invention) Conventionally, the crankshaft 2 has been made of a cast metal and further subjected to cutting. For this reason, there is a problem that the enclosure is heavy, and the number of processing steps is required, and there is also a large amount of cutting waste, resulting in high costs.

Therefore, the present invention has been made in consideration of the above circumstances.
The purpose of the present invention is to provide a crankshaft that is lightweight, requires no processing steps, produces less cutting waste, and can reduce costs.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a crankshaft in which a crank portion is formed at one end of the shaft via a balance weight, in which the shaft and the crank portion are connected to each other. The shaft and the crank part are connected to each other by a balance weight having a fitting hole in which the end portions of the shaft and the crank portion are fitted eccentrically so that the shaft holes communicate with each other.

(Function) Since the shaft and crank part are formed of IN, it is lightweight, and since the ends of the shaft and crank part are connected to each other by a balance weight, no machining process is required.

Since the shaft holes of the shaft and the crank part communicate with each other, they function as oil holes.

(Example) An example of the present invention will be described below in detail based on the accompanying drawings.

In FIG. 1 showing the crankshaft of a reciprocating compressor, 20 is a balance weight 2 at one end of the shaft 21.
This is the crank part with the mounting number numbered through 2. The shaft 21 and the crank portion 20 are each formed of a pipe material such as a steel pipe. Although the crank portion 20 is formed of a tube having a smaller diameter than the shaft 21, it may have the same diameter.

The respective ends of the shaft 21 and the crank part 20 are eccentrically connected to each other via a balance weight 22 so that the shaft holes 23 and 24 communicate with each other. As shown in FIG. 2, the balance way 22 has fitting holes 25 and 26 that overlap each other so that the ends of the shaft 21 and the crank part 20 can be fitted with their respective ends shifted in the radial direction. It consists of a circular flat plate made of steel plate etc. Shaft 21 and crank part 20
Each end of the balance weight 22 has a fitting hole 25.
, 26, and the silver soldering is fixed with etc.

Since the shaft 21 and the crank part 20 of the crankshaft are formed of tubular materials in this way, weight reduction can be achieved, and the ends of the shaft 21 and the crank part 20 made of these tubular materials are fitted eccentrically to each other. hole 25.26
Since the crankshafts are connected by the balance weight 22 having the above-described structure, unlike conventional crankshafts which are formed by further cutting a cast metal, the number of machining steps is small and costs can be reduced.

Fitting hole 25 for balance weight 22 when cutting pipe material
．． Since there is only a small amount of cutting waste when drilling the holes of 26,
Its processing is also easy. Further, since the inner diameter of the crankshaft formed of a pipe material is communicated with each other, there is no need to form a separate oil hole.

[Effects of the Invention 1 In summary, the present invention exhibits the following excellent effects.

(1) Since the shaft of the crankshaft and the crank portion are made of tubular material, weight can be reduced.

■ In addition, since the ends of the shaft made of these tube materials and the crank part are eccentrically connected to each other and are connected by a balance weight that has a fitting hole that fits so that the inner diameters communicate with each other, it is possible to cut the casting. Unlike conventional crankshafts, it requires fewer machining steps, produces less cutting waste, and reduces costs.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a crankshaft showing one embodiment of the present invention, the second factor is a plan view of a balance weight, and FIG. 3 is a longitudinal sectional view of a reciprocating compressor. In the figure, 20 is a crank part, 21 is a shaft, 22 is a balance weight, 23.24 is a shaft hole, and 25.26 is a fitting hole. Agent Patent Attorney Yudo Chika
Hiroshi Uji Figure 3

Claims (1)

[Claims] In a crankshaft for a reciprocating compressor in which a crank part is formed at one end of the shaft via a balance weight, the shaft and the crank part are formed of a pipe material,
A crankshaft characterized in that the end portions of the shaft and the crank portion are eccentrically connected to each other by a balance weight having a fitting hole into which the shaft holes are fitted so that the shaft holes communicate with each other.