JPH0735794B2 - Drive shaft manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a drive shaft, and more particularly to a drive shaft manufacturing method with an improved drive shaft structure which reduces the manufacturing cost and expands the range of usable manufacturing methods.

[0002]

2. Description of the Related Art Conventionally, in a scroll type compressor in which a pair of fitting scrolls perform relative orbital motion,
One scroll is usually fixed, the other orbits. Compressed fluid, such as refrigerant gas, is introduced from one side of the spiral and is compressed as the gas moves by the orbital motion of the device. The compressed gas is discharged from the center. This process is reversed and the device is driven by introducing compressed fluid from the center and further expanding.

As described above, the scroll machine can be used as a motor, that is, an expander.

[0004]

However, in the scroll compressor described above, the revolving motion of the moving scroll is unbalanced and off-axis, so that a vibration moment is generated. The vibration moment must be properly balanced by a suitable counterweight.
In current scroll-type compressors or other scroll-type rotating devices, a counterweight is provided at a great axial distance from the orbiting scroll.
It is necessary to keep the balance with the counterweight. Although such counterweights are carried by the drive shaft, it is expensive to manufacture drive shafts with counterweights by known techniques.

Such known manufacturing methods include machining a single cast piece of gray cast iron or malleable cast iron, machining a drive shaft from a casting, and the like.

That is, in the conventional method of manufacturing a drive shaft, whichever manufacturing method is used, the drive shaft is made by machining a single, substantially uniform piece of material, There was a problem that the manufacturing cost was high.

Therefore, a first technical object of the present invention is to improve the manufacturing method of the drive shaft in view of the above-mentioned drawbacks.

A second technical object of the present invention is to improve a method of manufacturing a drive shaft having a counterweight as a part of the drive shaft.

Further, a third technical object of the present invention is to improve the manufacturability of a drive shaft used for a scroll type compressor, that is, a motor, and use the counterweight as a part of the drive shaft, or the drive shaft. It is to provide a method of manufacturing a drive shaft that can be fixed to the.

A fourth technical object of the present invention is to provide a plastic insert having an oil passage therein, which can be attached to a drive shaft.

[0011]

According to the present invention, in a method of manufacturing a drive shaft 40 used in a scroll type compressor 10, a bearing for accommodating a portion 30 of a movable scroll 26 and causing the movable scroll to orbit. Forming the cap 42, fixing the bearing cap to the tube 41 defining the rotor shaft, and inserting a plastic insert 65 having at least one oil distribution hole 66, 66a, 66b formed therein. A step, and fixing the insert to the tube,
A method of manufacturing a drive shaft, which comprises:

Further, according to the present invention, there is provided a method of manufacturing the drive shaft, characterized by including a step of further providing another hole in the tube and the insert.

Further, according to the present invention, there is provided a method of manufacturing the drive shaft, which includes the steps of forming a counterweight 50 and fixing the counterweight to the pipe. .

Further, according to the present invention, the counterweight is
The method for manufacturing the drive shaft is characterized in that it is formed integrally with the bearing cap and is fixed to the tube as one unit.

That is, in order to solve the above-mentioned objects and other objects, according to the present invention, there is provided a main bearing portion formed by metal forging, casting or powder metallurgy, and a rotor stub connected thereto. A drive shaft having a steel tube firmly fixed to the main bearing portion by press fitting, friction welding, laser pressure welding, or the like can be obtained. The steel pipe is equipped with a plastic insert. This plastic insert is molded with appropriate vents and oil holes to expel the gas refrigerant and to pump oil through the rotor stub portion along the drive shaft rotor stub portion to the desired location. ing.

[0016]

Embodiments of the present invention will now be described with reference to the drawings.

It should be noted that although the present invention may have many applications, the best mode currently available for carrying out the present invention is the drive used in a scroll compressor 10 as shown in FIG. It will be described with reference to the axis.

The scroll compressor 10 includes a fixed scroll 2 provided in a shell or housing 12.
2 and a movable scroll 26 fixed against the rotation by an Oldham coupling 32. Shell 12
Is closed by providing an upper cap 16 at the top and a lower cap 14 at the bottom. Pressure chamber 1
The gas compressed by the compressor flows into 8. This gas is sent from the center of the fixed scroll that is firmly fixed in the housing 12, and then sent from the pressurizing chamber to the high pressure side outlet, that is, the discharge port 20. The male stub or stem 30 projects downward from the orbiting scroll 26 and engages a portion of the drive shaft 40 as described below.

By using an anti-rotation device such as an Oldham ring or joint 32, the orbiting scroll 26 is fixed against rotation. With this joint, the movable scroll 26 can revolve around the center of the fixed scroll 22, that is, the axis, but does not rotate.

Within the compressor housing 12 is an eccentric motor drive for the compressor 10. In addition, the eccentric motor drive has a stator 36 having a cylindrical passage 37 therethrough for housing a rotor assembly 38 rotatably mounted within the compressor housing 12.

By providing the rotor 38 within a generally cylindrical passage 37 formed in the stator 36, a small annular gap is created therebetween. By the drive shaft 40 having the rotor 38 press-fitted on the outer surface, the fixed scroll 2
2 and the movable scroll 26 perform relative movement.

The drive shaft 40 has a generally cylindrical upper bearing cap 42 at the upper end of the drive shaft 40. The slider block 46 is accommodated in the bearing cap 42 so that the stem portion 30 of the movable scroll 26 can be accommodated.

In this way, the rotor 3 in the stator 36 is
By the rotational movement of 8, the drive shaft 40 and the slider block 46 can perform the rotational movement. The stem 30 is eccentrically arranged with respect to the central axis of the drive shaft 40 and the slider block 4
Since the drive shaft 40 is rotated, the orbiting scroll 26 moves along the orbit with respect to the fixed scroll 22. Bearing cap 42
Are attached to the upper bearing 34.

Since the orbit of the movable scroll 26 is not balanced, the drive shaft 40 has a bearing cap 42.
A counterweight 50 is provided at a position just beside when viewed from the axial direction. The counterweight 50 is arcuate in the shape of an arcuate portion of the cylinder for an arc of about 160 degrees and is preferably provided opposite the radial position of offset of the orbiting scroll 26. The counterweight 50 may be formed integrally with the bearing cap 42, or may be formed as a separate piece that is preferably secured to the bearing cap to form an integral part. A counterweight 50 is provided on the radius of the cylindrical passage 37 in the stator 36 to allow the drive shaft and rotor assembly to be mounted from below even after the stator 36 is secured in the housing 12. ing.

Referring to FIGS. 2 and 3, the drive shaft 40 and the bearing cap 42 are molded with counterweight 50 as one or a separate piece of metal forging, casting or powder metallurgy. Is preferred.

On the other hand, when molding separately, it is preferable to fix the counterweight 50 to the bearing cap 42 to form an integral unit. Shaft part or rotor stub 41
Is preferably formed into a steel pipe by performing press fitting, friction welding, or laser pressure welding on the integrated bearing cap 42 and counterweight 50.

The bearing cap 42 and counterweight 50 can also be manufactured by a near net shape powder metal process, which typically greatly reduces the time it takes to machine this portion to attach to the drive shaft.

Since the rotor stub portion 41 of the drive shaft 40 is made like a steel pipe, there is no need for machining during assembly, and the cap 42 and the counterbalanced integral therewith by the method described above. It can be easily attached to the main bearing portion defined by the weight 50.

Therefore, it is possible to eliminate the expensive machining process and the waste of time which are conventionally required.

The plastic insert 65 is injection molded from any of a number of suitable thermoset engineering plastic materials commonly used in oil / refrigerant environments such as found inside refrigeration compressors. Has been done. All vents and oil holes are insert 65
Is molded into.

However, depending on factors such as molding cost, production volume, complexity of vents and oil / oil passages, a secondary treatment of drilling holes may be performed to partially or all vents and oil holes. You may form.

Further, the injection-molded plastic insert 65 is deburred and washed to meet the specifications determined according to the final purpose of use. If desired, the insert 65 manufactured elsewhere may be packaged for use and sent to the compressor assembly site.

The bearing cap 42 and the counterweight 50 integral therewith are assembled or machined and attached to the pipe section 41, and the assembly thus obtained is cleaned and then the pipe of the drive shaft 40 is Hole 41a of part 41
Insert the insert 65 into. Normally, this is a light press fit /
The interference fit is performed by heating the drive shaft 40. The insert 65 is inserted into the heated tube section 41 and the tube 41 is contracted around the insert. It is also possible to use an adhesive instead of press-fitting.

For proper oil / lubrication flow, insert 65 must be accurately positioned with respect to bearing cap 42 during insertion. The bearing cap 42 is provided with the port 42a, and the vent port 41c and the oil supply port 4 are provided.
It is also possible to maintain such an arrangement by a fixing method such that the oil distribution hole 66 can be arranged by providing the pipe 41 with the 1b.

On the other hand, as best seen in FIG. 3, the insert 65 is molded with slots provided axially to engage corresponding upsets with slots 65a of the tube 41 such as slots and keys. Good.

When using an adhesive, a curing / heating cycle is required depending on the adhesive used. In addition, hole 6
The oil supply pipe 62 is press-fitted or adhered to the chamber 67 which is the lower end of 6 by an adhesive.

Once assembled as described above, drive shaft 40
The lower end of the is supported by the lower bearing 58. The lower bearing is for mounting the lower end of the drive shaft 40 at a position where fluid can move between an oil sump, which is a source of oil supply to various bearing surfaces, that is, a reservoir 64. Oil supply pipe 62
Extends from the chamber 67 at the lower end of the drive shaft 40 and is inserted into the sump 64.

The oil distribution hole 66 is formed by the pipe 41 and the insert 65.
The shaft 67 extends from the chamber 67 formed at the lower end of the insert 65 along the longitudinal direction of the drive shaft 40 to the opening 42a of the bearing cap 42 in a state of being displaced from the shaft. The bearing cap 42 serves as an oil receiving chamber.

The oil distribution hole 66 is inclined and displaced from the center axis of rotation of the drive shaft 40 on the side opposite to the position of the counterweight 50. Due to the beveled or offset holes 66, they act as centrifugal pumps for sucking lubricant. An appropriate number of oil distribution channels such as 66b and corresponding ports 41b and vent channels 66a and corresponding ports 41c are connected to the oil distribution holes 66 to form upper bearings and lower bearings, or as a unit. Ventilation holes and oil supply holes for other positions where oil supply is required by the centrifugal action generated when the rotor 38 and the drive shaft 40 rotate. 6
By using channels such as 6a and 66b and their corresponding ports 41b and 41c, there is no need to drill or drill holes in the drive shaft as in the prior art. Alternatively, there is also a method in which only the holes 66 and the openings 42a are initially formed, and then the channels 66a and 66b and the ports 41b and 41c are formed after the inserts 65 are provided at appropriate positions.

Although the preferred embodiments of the present invention have been described above with reference to the drawings, various modifications may be made without departing from the scope of the claims and the elements of the present invention may be replaced with their equivalents. It will be appreciated by those skilled in the art that this is possible.

Furthermore, various modifications can be made to adapt it to any situation or material without departing from the basic scope of the invention. For example, if the mass of counterweight 50 needs to be increased or decreased, it can be made of a different material than bearing cap 42.

Thus, the invention is not limited to the particular embodiments described with reference to the drawings as the most suitable form for applying it, but is covered by the appended claims. It is considered to include any other embodiments.

[0043]

As described above, according to the present invention,
There is an effect that a manufacturing method of a drive shaft having a counterweight as a part of the drive shaft can be obtained.

Further, according to the present invention, there is an effect that it is possible to provide a plastic insert which has an oil flow path inside and can be attached to the drive shaft.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a scroll type compressor including a drive shaft manufactured by using the method according to the present invention.

FIG. 2 is a vertical cross-sectional view showing a drive shaft in FIG.

3 is a perspective view showing a drive shaft in FIG. 1. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Scroll type compressor 12 ... Housing (shell) 14 ... Lower cap 16 ... Upper cap 18 ... Pressurizing chamber 20 ... Discharge port 22 ... Fixed scroll 26 ... Movable scroll 30 ... Stem 32 ... Joint 34 ... Upper bearing 36 ... Stator 37 ... passage 38 ... rotor assembly 40 ... drive shaft 41 ... rotor stub 42 ... upper bearing cap 46 ... slider block 50 ... counterweight 58 ... lower bearing 62 ... oil supply pipe 64 ... reservoir 65 ... insert 67 ... chamber

Claims (4)

[Claims] 1. A method of manufacturing a drive shaft 40 used in a scroll type compressor 10, comprising a step of accommodating a portion 30 of a movable scroll 26 and forming a bearing cap 42 for causing the movable scroll to orbit. Fixing the bearing cap to the pipe 41 defining the pipe, inserting a plastic insert 65 having at least one oil distribution hole 66, 66a, 66b into the pipe, and fixing the insert to the pipe. A method of manufacturing a drive shaft, comprising: 2. The method of manufacturing a drive shaft according to claim 1, further comprising the step of providing another hole in the tube and the insert. 3. The method of manufacturing a drive shaft according to claim 1, further comprising the steps of forming a counterweight 50 and fixing the counterweight to the pipe. 4. The method of manufacturing a drive shaft according to claim 3, wherein the counterweight is formed integrally with the bearing cap and is fixed to the pipe as one unit.