JP2000042879A - Double conical roller and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing technique for manufacturing a double conical roller with high finishing accuracy at a low cost, using a centerless grinding technique. SOLUTION: After forming material W1 in spherical shape, spherical roller material W2 is formed into both spherical surfaces of a double conical roller W by infeed grinding of a centerless grinding machine 10. A steel ball which is a bearing element for a ball bearing on sale is usable as the spherical roller material W2. The grinding wheel surface of a grinding wheel 11, the rotating support face of a regulating wheel 12, and the support face of a blade 13 of the centerless grinding machine 10 are provided with profiles corresponding to both conical surfaces of the double conical roller W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double conical roller and a method of manufacturing the same, and more particularly, to a double conical roller having a pair of conical surfaces suitably used as rolling elements such as a scroll thrust bearing of a scroll compressor. The present invention relates to a technology for manufacturing a double tapered roller.

[0002]

2. Description of the Related Art A scroll compressor is a kind of rotary compressor, in which the fluid is continuously compressed, has less torque fluctuations and vibrations, and operates at high speed as compared with conventional reciprocating compressors. In recent years, practical application has been actively promoted.

[0003] This type of compressor is provided with a thrust force support structure capable of driving the scroll. This support structure constitutes a kind of thrust bearing, and a sphere such as a steel ball is used as a rolling element. In such a sphere, since the supporting state is point contact, high-speed long-term There was a problem that the durability was poor in use.

In this regard, recently, as shown in FIG. 9A, a scroll compressor having a thrust force support structure has been proposed (for example, Japanese Utility Model Laid-Open No. 61-82086, Japanese Unexamined Patent Publication No. 62-107284, etc.).

The basic structure of this compressor is as shown in the figure.
In the housing a, a fixed scroll member c having a spiral body b is fixed, and a revolving scroll member e having a spiral body d meshing with the spiral body b is supported by a thrust force support structure f so as to be capable of turning or revolving. The orbiting scroll member e is drivingly connected to a driving source (not shown) via a crank pin g.

The support structure f is in the form of a type of thrust bearing as described above, and a plurality of recesses h and i are provided on the inner surface of the housing a and the opposing surface of the revolving scroll member e, respectively, and These recesses h, i
A bi-conical rolling element (bi-conical roller) W is interposed so as to be able to roll.

[0007] By the rotation of the crank pin g, the revolving scroll member e is turned into the stationary scroll member c.
The fluid gas sucked from the suction port j is revolved without rotating, and compressed by the compression chamber formed between the spiral bodies b and d, and then discharged from the discharge port k. Have been.

In this case, as shown in the schematic diagram of FIG. 9 (b), the outer peripheral surfaces Wa and Wb of the double tapered roller W have concave portions h and i.
The rolling motion is performed in a line contact state with the flat bottom surfaces m and n, and the durability is remarkably improved as compared with the conventional rolling element made of a sphere, and it can withstand long-term use at high speed. There is an advantage of gaining.

[0009]

In spite of having such excellent durability, the scroll type compressor having such a thrust force supporting structure f has a manufacturing technology of the double tapered roller W described above. The fact is that it has not yet been put to practical use due to its lack of establishment.

That is, the double conical roller W is an abacus spherical bearing element in which the upper and lower outer peripheral surfaces Wa and Wb have conical shapes as shown in the figure. Although high-precision finishing is required for the surfaces Wa and Wb, and it is necessary to secure mass productivity as a machine element at the same time, there is no manufacturing technology that can satisfy all of these conditions. Mass production processing of high precision double tapered roller W was not possible.

In this regard, the Applicant has conducted various tests,
Through repeated research, the following manufacturing method was developed (FIG. 10).
reference).

First, a rod-shaped or linear material o is cut into a cutting machine p.
And cut to a predetermined size to obtain a short roller material q (FIG. 10).
), And the roller material q is formed into a pair of forging dies r,
The material is formed into a substantially bicone-shaped material s by forging using r (FIG. 10). Next, the roller material s having a substantially biconical shape is subjected to a heat treatment to have a predetermined hardness (see FIG. 10), and thereafter, is subjected to infeed grinding with a surface grinder or a centerless grinder to obtain a final finished shape. The both conical surfaces of the both conical rollers W are formed (FIG. 10 or ').
Finally, a super-finishing process such as a lapping process or a barrel process is performed (in FIG. 10, a lapping process in the illustrated case).

However, in such a manufacturing method,
The following issues left room for further completion.

That is, as shown in FIG. 11, the double conical roller W manufactured as described above has upper and lower biconical surfaces Wa,
In the method of grinding into a biconical shape having Wb, that is, a so-called abacus sphere, the roller material s is formed into a substantially biconical shape by forging in advance, and the method of performing the grinding process, which is a finishing process, on the basis of this molded surface, involves forging Due to the variation of the forging dimensions due to the processing, the dimensional accuracy of the forged conical surface is low, so that the allowance distribution is different at the time of grinding the two conical surfaces Wa and Wb, and a perfect symmetrical shape is not obtained (l ₁ ≠).
l ₃ , l ₅ ≠ l ₆ , l ₂ ≠ l ₄ ).

Further, even after being ground into a so-called abacus having a biconical shape having upper and lower conical surfaces Wa and Wb,
Each corner portion Wc remains a forged surface formed by forging in advance, and the dimensional difference of each corner portion Wc after finishing is large due to the variation in forging dimensions due to forging (l ₁ ≠ l ₂ , l ₃ ≠ l ₄ or l ₁ , l ₂ ,
l ₃ and l ₄ do not have the same size for each lot).

As a result, with the above-described manufacturing method, a high-precision finished surface cannot be obtained, and further improvement has been demanded in order to obtain a double-tapered roller that is sufficiently satisfactory for practical use.

The present invention has been made in view of the conventional problems as described above, as well as the problems of the manufacturing technology in the prior tests and research stages of the present applicant. By utilizing the centerless grinding technology with high machining efficiency, a double tapered roller manufacturing technology that can manufacture a double tapered roller that is a short rotating body with a non-cylindrical outer diameter surface with high finishing accuracy at low cost Is to provide.

[0018]

In order to achieve the above object, a method for manufacturing a double tapered roller according to the present invention comprises forming a roller material into a spherical shape, and then subjecting the spherical roller material to in-feed grinding of a centerless grinding machine. In a preferred embodiment, after forming the roller material into a spherical shape, the spherical roller material is subjected to a heat treatment to a predetermined hardness. As the spherical roller material, a steel ball which is a bearing element for a commercially available ball bearing can be used.

Preferably, when the centerless grinding machine is subjected to in-feed grinding to form the conical surfaces of the conical rollers, the spherical roller material is formed with the conical surfaces while leaving a part of the surface thereof. It is preferable to perform grinding so as to form crowning on both conical surfaces.

The centerless grinding machine includes a grinding wheel having a grinding wheel surface having a profile corresponding to the both conical surfaces of the tapered rollers, and an adjusting wheel having a rotation supporting surface having a profile corresponding to the both conical surfaces of the tapered rollers. A blade having a support surface that supports both conical surfaces of the tapered rollers is used so that the axis of the grinding wheel and the rotation center axis of the tapered rollers are parallel to each other. Preferably has a V-shaped profile along the ridge line of the bi-conical surface of the bi-conical roller, or has a spherical profile corresponding to the spherical surface of the spherical roller material. .

Further, in order to mass-produce the double conical rollers, the grinding wheel surface of the grinding wheel, the rotating support surface of the adjusting wheel, and the supporting surface of the blade are formed of a plurality of the double conical rollers aligned in the rotation center axis direction. It is preferred to have a profile that matches both conical surfaces.

In the present invention, after the roller material is formed into a spherical shape by forging or the like in advance, more preferably, the spherical roller material is subjected to a heat treatment so as to have a sufficient hardness as a bearing element. High finishing accuracy is achieved by forming the conical surfaces of the conical rollers by infeed grinding of a centerless grinding machine.

In other words, the shape formed from the roller material is a spherical surface on which the forging dimension is unlikely to vary due to forging, and the two conical surfaces ground based on this spherical surface have a uniform allowance for grinding. Yes, the dimensional accuracy is stable and a perfect symmetrical shape is obtained.

Further, each corner portion which remains as a forged surface in the final finished shape is also a spherical surface where variation in forging dimensions is hard to occur, and there is almost no dimensional difference between the corner portions and the surface is uniform.

The double tapered roller manufactured as described above is suitably used as a rolling element of a scroll thrust bearing used as a thrust bearing of a scroll compressor or the like.

[0026]

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

Embodiment 1 The method of manufacturing a double tapered roller according to the present invention is suitably used as a rolling element such as a scroll thrust bearing of a scroll compressor as shown in FIG. 9 (a). This is for mass production of the double tapered rollers W. This double tapered roller W
Has a pair of conical surfaces Wa and Wb as shown in FIG. 5, and has a corner portion of the double conical rollers W, that is, a vertex portion of the double conical rollers W and boundary portions Wc and Wd of the two conical surfaces Wa and Wb. Each has a spherical surface. Further, the angle between the upper and lower vertices of the double tapered rollers W, that is, the cone angle θ is 90
°, and therefore the intersection angle between the two conical surfaces Wa and Wb is also set to 90 °.

The method of manufacturing the double tapered roller is characterized in that the roller material is formed into a spherical shape in advance by forging or the like, and the spherical roller material is subjected to a heat treatment to have a sufficient hardness as a bearing element. By the in-feed grinding of the centerless grinding machine, the conical surface W of the conical roller W
a, Wb is to be formed, and the specific steps include six steps as shown in FIG. Hereinafter, each step will be described sequentially.

Step of Forming Roller Material W ₁ (FIG. 1) This step is to form the amount (volume) of the roller material W ₁ required for forming the double-cone roller W as the final product. the, from the linear or rod-shaped material W ₀ having a predetermined diameter comprising a bearing steel, the cutting machine 1 and cut into a predetermined length corresponding to the two tapered roller W, part length of the roller material W ₁ Molding.

Forming process of spherical roller material W ₂ (FIG. 1)
This process is based on the short roller material W ₁ formed in the previous process.
Is formed into a spherical shape, specifically, a spherical forming surface 2
Using a pair of forging type 3a, 3b having pressurizes the roller material W _1, to forging the spherical rollers material W _2.

Heat treatment step: (FIG. 1) In this step, the spherical roller material W ₂ formed in the previous step is heat-treated so as to obtain a predetermined hardness. Specifically, the spherical roller material W ₂ is heated to a predetermined temperature, by adjusting the cooling rate, the required tissue, the nature, to impart sufficient hardness to the spherical rollers material W ₂ as the rolling elements of the bearing.

Lapping step: (FIG. 1) This step is performed in a spherical roller blank W ₂ heat-treated in the previous step.
Specifically, a spherical roller material W having a spiral wrap groove 4 having a V-shaped cross section as shown in the figure and having relatively rotating laps 5a and 5b is provided.
₂ is passed through while rolling added wrap agent (lapping powder), and subjected to lapping the spherical surface of the spherical rollers material W _2, and true spherical surface having a uniform diameter D.

[0033] As the spherical rollers material W ₂ molded as described above, may be used a steel ball for a commercial ball bearings. By doing so, the manufacturing cost of the tapered rollers W can be significantly reduced.

Step of forming double tapered roller W: (FIG. 1) In this step, the spherical surface of the heat-treated spherical roller material W ₂ lap-finished in the previous step is combined with the double cone of the double tapered roller W which is the final shape. The molding is performed on the surfaces Wa and Wb. Specifically, this molding process is performed by in-feed (feeding) grinding of the centerless grinding machine 10 as shown in (a) and (b). The configuration of the main part of the centerless grinding machine 10 used is shown in FIGS.

Specifically, the centerless grinding machine 10 collectively rotates a plurality (three in the illustrated case) of the heat-treated spherical roller materials W ₂ lap-finished in the previous step and rotationally supports the material at the grinding position. While the grinding is performed simultaneously by the in-feed grinding method, the conical surfaces Wa and Wb of the conical roller W shown in FIG.
The adjusting wheel 12 and the blade 13 are configured as main parts.

The grinding wheel 11 grinds the outer surface of a workpiece W, W,... (Spherical roller material W ₂ → double conical roller W), and its rotary spindle 15 has a conventionally known general basic structure. Although not shown, it is rotatably mounted on a grinding wheel platform provided on the apparatus bed, and is linked to a drive source such as a drive motor. Further, the grinding wheel 11 can be reciprocated in the cutting feed direction X.

The adjusting wheel 12 rotatably supports the outer diameter surfaces of the workpieces W, W,..., And the rotating main shaft 16 has a conventionally well-known general basic structure like the grinding wheel 11 described above.
Although not shown, it is rotatably mounted on an adjustment chassis provided on the device bed, and is linked to a drive source such as a drive motor. The adjustment wheel 12 is capable of reciprocating in the cutting feed direction X.

The feed angle (inclination angle) of the adjusting wheel 12, that is, the inclination angle of the rotary main shaft 16 can be adjusted, but this angle is set to substantially 0 °. Are configured so that no axial thrust acts on the workpieces W, W,.

The blade 13 supports the lower part of the outer diameter surface of the works W, W,... And is fixed on a work rest 17 provided on the apparatus bed.

The grinding wheel surface 11a of the grinding wheel 11, the rotating support surface 12a of the adjusting wheel 12, and the support surface 13a of the blade 13
Has a profile corresponding to both conical surfaces Wa, Wb, Wa, Wb, Wa, Wb of three works W, W, W aligned in the axial direction.

More specifically, as shown in FIG. 3, the grinding wheel surface 11a of the grinding wheel 11 is composed of three grinding surfaces 20, 20, 20 arranged at regular intervals. , V-shaped profile (cross-sectional contour shape) corresponding to the finished shape dimensions of both conical surfaces Wa and Wb of the workpiece W
Having.

The size of the V-shaped ground surface is set so that the whole of the two conical surfaces Wa and Wb can be ground. In other words, V constituting the grinding surface 20
The U-shaped groove has both side walls forming an intersection angle θ of 90 ° similarly to the above-mentioned both conical surfaces Wa and Wb of the work W, and the depth dimension H is the maximum finish radius of the work W,
That is, the radius is set to be larger than the radius of the bottom position of both conical surfaces Wa and Wb.

The rotation support surface 12a of the adjusting wheel 12 is
The grinding wheel 11 is composed of three rotation supporting portions 21, 21, 21 arranged opposite to the grinding surfaces 20, 20, 20, respectively.
a, a profile for rotatably supporting a part of Wb.

Specifically, as shown in FIG.
.. Are integrally formed in a stacked manner with four adjustment disks 22, 22... Via a spacer disk 23, and the above-described rotation is performed by the edge surfaces 22a, 22b of the adjacent adjustment disks 22, 22. The support portion 21 is configured. These two edge surfaces 2
2a and 22b are configured to form a part of an annular groove having the same profile as the grinding surface 20 of the opposed grinding wheel 11. The outer diameter of the spacer disk 23 between the both end surfaces 22a and 22b is determined by the outer peripheral surface of the spacer disk 23.
It is set so as not to come into contact with the work W supported by 2a and 22b. With such a configuration, even if the conical surfaces Wa and Wb of the work W are deformed as the grinding process proceeds, the both end surfaces 22a and 22b are always stable and the conical surfaces Wa and Wb of the work W are always stable. Wb is rotatably supported.

The support surface 13a of the blade 13 has three support surfaces 24, 24 which are respectively opposed to the grinding surfaces 20, 20, 20 of the grinding wheel 11 and the rotary support portions 21, 21, 21 of the adjusting wheel 12. , 24, each supporting surface 24 has a profile corresponding to a part of the two conical surfaces Wa, Wb of the work W, and the two conical surfaces Wa, Wb of the work W.
Is supported so that its rotation center axis is parallel to the axis of the rotating main shaft 15 of the grinding wheel 11.

More specifically, as shown in FIG. 4, the blade 13 is composed of three blade members 25, 25, 25 mounted on the work rest 17 in an upright manner. The supporting surface 24 has a profile corresponding to the conical surfaces Wa and Wb.

That is, the support surface 24 has a V-shaped profile corresponding to the finished shape of the conical surfaces Wa and Wb of the work W, that is, along the ridge line of the conical surfaces Wa and Wb. V that supports the lower part of the conical surfaces Wa and Wb
It is in the form of an inclined groove. Accordingly, even if the two conical surfaces Wa and Wb of the work W are deformed with the progress of the grinding, the support surface 24 keeps the two conical surfaces Wa and Wb stable at all times, and the rotation center axis of the work W is shifted. The grinding wheel 11 is supported so as to be parallel to the axis of the rotating spindle 15.

Further, above the three works W, W, W rotatably supported by the blade 13, these works W, W, W, W
An upper blade 26 (see FIG. 2) for supporting the upper portions of the W conical surfaces Wa, Wb,... From above is provided. Although the specific configuration of the support surface of the upper blade 26 is not shown, the configuration is the same as that of the support surface 13a of the blade 13, and the two conical surfaces Wa, W of the workpieces W, W, W are simply provided.
b,... A flat surface or the like that presses the upper portion is also employed. In short, the structure is such that the work W can be effectively prevented from floating during grinding.

Although not shown, a rotary dresser for dressing both the grinding wheel surface 11a of the grinding wheel 11 and the rotation support surface 12a of the adjusting wheel 12 is provided. This rotary dresser is provided with the above-mentioned grinding wheel surface 11a. And a profile corresponding to the rotation support surface 12a, that is, a cross-sectional contour shape which is fitted closely to the grinding wheel surface 11a and the rotation support surface 12a, and while rotating, the grinding wheel surface 11a of the grinding wheel 11 and the adjustment wheel 12 Rotation support surface 1
2a is simultaneously or individually dressed.

In the centerless grinding machine 10 configured as described above, the three works W, W, W, W, W,
With the upper blade 26 supported from above with respect to W, the grinding wheel 11 and the adjustment wheel 12 are rotationally driven, and the grinding wheel 11 is cut into the workpieces W, W, and W relatively, Grinding is performed on the outer diameter surface of the work W.

In this case, the workpieces W, W, W of the grinding wheel 11
The relative depth of cut for the surface clogging spherical portion of the spherical roller material W ₂ (Wc, Wd), leaving the two conical surfaces W
a and Wb are set.

The center axes of rotation of the workpieces W, W, W are supported so as to be parallel to the axis of the grinding wheel 11, and the feed angle of the adjusting wheel 12 is 0 °.
No axial thrust acts on W. Also, in this case, the cutting wheel of the grinding wheel 11 is cut and fed with the position of the grinding wheel 11 and the blade 13 constant, or the wheel of the adjusting wheel 12 is fixed and the position of the blade 13 and the adjusting wheel 12 is constant. The car 11 is cut and fed.

When the above-mentioned grinding step is repeated,
Since the grinding surface 11a of the grinding wheel 11 and the rotating support surface 12a of the adjusting wheel 12 are crushed, clogged or worn, the dressing process by the rotary dresser is performed at predetermined intervals.
a and the rotating support surface 12a of the adjusting wheel 12 are simultaneously or sequentially separately dressed. In particular, when the grinding wheel 11 and the adjustment wheel 12 are dressed at the same time, clogging of the rotary dresser is effectively prevented, and efficient dressing is performed.
As a result of tests and research conducted by the inventors, the results have been found.

Super-finishing step (FIG. 1) This step is to final-finish both conical surfaces Wa and Wb of the double-cone roller W ground to the final shape in the previous step by super-finishing. Specifically, the same lap finish as in the above process is applied.

That is, a lapping agent is added to the conical rollers W to pass between the laps 31a and 31b which have a straight wrap groove 30 having a right-angle V-shaped cross section as shown in the figure and which reciprocate relatively. , The double conical surfaces Wa, Wb of the double conical rollers W
Lapping to improve finishing accuracy.

Although not shown, other super finishing such as barrel processing may be performed instead of the lap finishing.

Thus, a series of these steps (the step of forming the roller material W ₁ → the step of forming the spherical roller material W ₂ →
Through the heat treatment step, the lapping step, the forming step of the double tapered roller W, and the super-finishing step), the double tapered roller W shown in FIG. 5 is completed.

[0058] As described above, the roller is formed into a spherical shape in advance by forging material W _1, after a sufficient hardness as the bearing element is subjected to a heat treatment to the spherical rollers material W _2, the spherical rollers material W ₂ By forming the conical surfaces Wa and Wb of the conical rollers W by in-feed grinding of the centerless grinding machine 10, high finishing accuracy can be realized.

That is, the shape formed from the roller material W ₁ is a spherical surface on which forging does not easily vary in forging dimensions, and the two conical surfaces Wa ground on the basis of this spherical surface are set aside during grinding. Are uniform, the dimensional accuracy is stable, and a perfect symmetrical shape is obtained.
_{1 = l 3, l 5 =} l 6, l 2 = l 4).

Also, each of the corner portions Wc and Wd, which remain the forged surface in the final finished shape, is also a spherical surface where variation in the forging dimensions is hard to occur, and there is almost no dimensional difference between the corner portions. l ₁ = l ₂ , l ₃
= L ₄ ).

In the grinding step (FIG. 1) in the manufacturing method according to the present embodiment, the grinding wheel surface 11a (grinding surfaces 20, 20, 20) of the grinding wheel 11 and the adjusting wheel 1
2 rotation support surfaces 12a (rotation support portions 21, 21, 21)
Are the three conical surfaces W of three aligned works W, W, W
a, Wb,... and a support surface 13a of the blade 13 (support surfaces 24, 2).
4, 24), so that the center axes of rotation of the workpieces W, W, W are parallel to the axis of the grinding wheel 11, and the two conical surfaces Wa,
.. Wb,... And the adjusting wheel 12 is not provided with a feed angle, so that in the above-mentioned grinding process, the workpieces W, W, W may fall even though they are relatively short. Therefore, the grinding is always performed with a stable alignment state.

As a result, the three double tapered rollers W, W, W are ground simultaneously and with high machining accuracy, and a large number of works W, W,. Mass production processing is also possible, and a large reduction in manufacturing cost is realized by a large amount of processing of the double tapered roller W, which has been impossible in the past.

The double tapered roller W manufactured as described above
9 is suitably applied, for example, as a rolling element of a scroll thrust bearing used as a thrust bearing of a scroll compressor as shown in FIG. 9 (a), and the outer peripheral surfaces Wa and Wb of the double tapered roller W are formed as shown in FIG. As shown in FIG.
Rolling motion is performed in a line contact state with respect to the flat bottom surfaces m and n. As a result, the durability is remarkably improved as compared with the conventional scroll type compressor using a spherical rolling element as the above-mentioned scroll thrust bearing. The operation of the scroll-type compression machine that can fully operate the compressor can be realized.

When the spherical roller material W ₂ is subjected to in-feed grinding of the centerless grinding machine 10 to form the conical surfaces Wa and Wb of the conical rollers W, the conical surfaces Wa and Wb are crowned. It is also possible to grind to provide (crawning). That is, as shown by the two-dot chain line in FIG. 5, both conical surfaces Wa and Wb and spherical surfaces Wc and Wd
By providing the crowning 30 at the boundary portions between the two conical surfaces Wa and Wb, it is possible to effectively prevent the generation of the edge load due to the load at both end portions of the two conical surfaces Wa and Wb.

[0065] Embodiment specific steps of the two tapered roller manufacturing method according to the two embodiments is shown in FIG. 6, the roller step of forming material W _1, the molding process of the spherical rollers material W _2, spherical grinding It consists of six steps: a step, a heat treatment step, a forming step of the double tapered roller W, and a super finishing step. Hereinafter, each step will be described sequentially.

Step of Forming Roller Material W ₁ (FIG. 6) This step is to cut the linear or rod-shaped material W ₀ into a predetermined size to form a short roller material W _1. Are the same as the steps in the first embodiment.

Step of Forming Spherical Roller Material W ₂ (FIG. 6)
This process is based on the short roller material W ₁ formed in the previous process.
Is formed into a spherical shape by forging, and is specifically the same as the process in the first embodiment.

Spherical grinding step (FIG. 6) This step is performed in a spherical roller blank W forged in the previous step.
The spherical surface material ₂ is subjected to a rough grinding process. Specifically, the spherical roller material W is formed by infeed grinding of a centerless grinding machine 110 having a main part configuration as shown in FIGS.
Rough grinding of the spherical surface of ₂ .

In this case, the grinding surface 11a of the grinding wheel 11, the rotating support surface 12a of the adjusting wheel 12 and the support surface 13a of the blade 13 in the centerless grinding machine 110 are not shown, but are arranged in three axially aligned works ( Spherical roller material) W ₂ , W ₂ , and W ₂ are provided with profiles corresponding to the forged spherical surfaces. Other configurations and operations are the same as those of the first embodiment.
This is the same as the case of the grinding by the centerless grinding machine 10 in.

[0070] a heat treatment step (6) in this step, before the spherical rollers material W ₂ formed into a true sphere in which a heat treatment so as to obtain a predetermined hardness at step, the first embodiment is specifically It is the same as the process.

Forming step of double tapered roller W: (FIG. 6) This step is performed in the spherical roller material W ₂ heat-treated in the previous step.
Of the conical surface W of the conical roller W which is the final shape
a, Wb, which is the same as the process in the first embodiment.

Super-finishing step: (FIG. 6) This step is to final-finish both conical surfaces Wa and Wb of the double-conical roller W ground to the final shape in the previous step by super-finishing. Specifically, it is the same as the process in the first embodiment.

[0073] Thus, these series of steps (around the molding process of the material W ₁ → spherical roller material W ₂ of the molding process →
Through the spherical grinding process → the heat treatment process → the forming process of the double tapered roller W → the superfinishing process), the double tapered roller W shown in FIG. 5 is completed. Other configurations and operations are the same as those of the first embodiment.

Embodiment 3 Specific steps of the method for manufacturing a double tapered roller according to the present embodiment are shown in FIG. 7, wherein a forming step of a roller material W _1, a forming step of a spherical roller material W ₂ , and a double tapered roller Rough forming process of W, heat treatment process,
It consists of six steps: a finish forming step of the double tapered roller W and a super finishing step. Hereinafter, each step will be described sequentially.

Step of Forming Roller Material W ₁ (FIG. 7) This step is to cut a linear or rod-shaped material W ₀ into a predetermined size to form a short roller material W _1. Are the same as the steps in the first embodiment.

Step of Forming Spherical Roller Material W ₂ (FIG. 7)
This process is based on the short roller material W ₁ formed in the previous process.
Is formed into a spherical shape by forging, and is specifically the same as the process in the first embodiment.

Rough Forming Step of Double Conical Roller W: (FIG. 7) This step is performed by forming the spherical roller material W forged in the previous step.
₂ spherical surface, the bi-conical surface W of the conical roller W which is the final shape
a and Wb are roughly formed, specifically, as shown in FIGS.
Centerless grinding machine 21 having the main components shown in FIG.
0 infeed grinding, and the spherical roller material W ₂
Is roughly ground to the conical surfaces Wa and Wb of the conical rollers W.

In this case, the grinding wheel surface 11a of the grinding wheel 11 and the rotation supporting surface 1 of the adjusting wheel 12 in the centerless grinding machine 10 in this case.
2a and the support surface 13a of the blade 13 are shown in FIGS.
As shown in FIG. 3, the three conical surfaces Wa, Wb, Wa, Wb, W of the three workpieces W, W, W aligned in the axial direction.
a, Wb. Other configurations and operations are the same as those in the case of the grinding by the centerless grinding machine 10 in the first embodiment.

[0079] a heat treatment step (7) in this step, before the spherical rollers material W ₂ formed into a true sphere in which a heat treatment so as to obtain a predetermined hardness at step, the first embodiment is specifically It is the same as the process.

Forming Step of Double Conical Roller W: (FIG. 7) This step is performed in the spherical roller material W ₂ heat-treated in the previous step.
Of the conical surface W of the conical roller W which is the final shape
a, Wb, which is the same as the process in the first embodiment.

Super-finishing Step: (FIG. 7) This step is to final-finish both conical surfaces Wa and Wb of the double-cone roller W ground to the final shape in the previous step by super-finishing. Specifically, it is the same as the process in the first embodiment.

[0082] Thus, these series of steps (around the molding process of the material W ₁ → spherical roller material W ₂ of the molding process →
The double conical roller W shown in FIG. 5 is completed through the rough forming step of the double tapered roller W → the heat treatment step → the finish forming step of the double tapered roller W → the superfinishing step). Other configurations and operations are the same as those of the first embodiment.

The above-described embodiments merely show preferred embodiments of the present invention, and the present invention is not limited to these embodiments, and various design changes can be made within the scope. As an example, the following modifications can be considered.

[0084] (1) Specific processes of both tapered rollers producing method according to the present invention is not limited to those shown in the first to third embodiments, the roller is formed into spherical shape by preliminarily forging or the like material W _1, after a sufficient hardness as the bearing element is subjected to a heat treatment to the spherical rollers material W _2, the infeed grinding of the spherical rollers material W ₂ centerless grinding machine 10, both conical surfaces of the tapered roller W which is the final product Other steps can be adopted as long as the Wa and Wb are formed.

(2) The specific structure of the centerless grinding machine 10 is not limited to those shown in FIGS. 2 to 4, and other structures can be adopted as long as they have the same function.

For example, as shown in FIG. 8, the specific configuration of the blade 13 is such that its support surface 13a (24, 24, 2)
4) may be set to include the profile of the spherical shape corresponding to the spherical surface of the spherical rollers material W _2. Thus, even if the two conical surfaces Wa and Wb of the work W are deformed with the progress of the grinding, the support surface 24 is kept on the spherical surface W of the work W.
In a state where d is always stable, the work W is supported such that the rotation center axis of the work W is parallel to the axis of the rotation spindle 15 of the grinding wheel 11.

In the illustrated embodiment, the three workpieces W, W, W are structured to be collectively ground. However, the number of workpieces W to be processed can be appropriately increased or decreased according to the purpose. Of course there is.

[0088]

As described above, according to the present invention,
After the roller material is formed into a spherical shape, the spherical roller material is shaped into a conical surface of the conical roller by infeed grinding of a centerless grinder, realizing high finishing accuracy in the production of the conical roller. .

In other words, the shape formed from the roller material is a spherical surface on which the forging dimension is not likely to vary due to the forging, and the two conical surfaces ground on this spherical surface have a uniform allowance for grinding. Yes, the dimensional accuracy is stable and a perfect symmetrical shape can be obtained, and each corner portion that remains the forged surface in the final finished shape also becomes a spherical surface where variation in forging dimensions does not easily occur, and the dimensions of each corner portion There is almost no difference and it can be made uniform.

Further, as a centerless grinding machine used in the manufacturing method of the present invention, a grinding wheel having a grinding wheel surface having a profile corresponding to the both conical surfaces of the tapered rollers, and a rotating support of a profile matching the both conical surfaces of the tapered rollers are provided. By adopting a configuration having a blade having a support surface that supports both conical surfaces of the tapered rollers, so that the adjustment wheel having the surface and the rotation center axis of the tapered rollers are parallel to the axis of the grinding wheel. The tapered rollers are short (the length in the axial direction is relatively small with respect to the outer diameter). It will be ground. As a result,
A large number of double tapered rollers can be mass-produced continuously and automatically, and the production cost by mass production can be significantly reduced.

Therefore, the centerless grinding technology can be applied to the double tapered roller, which is a typical work having high finishing accuracy (surface roughness, roundness, etc.) and mass productivity, and has a high processing accuracy. And high-efficiency grinding.
A large number of double tapered rollers can be mass-produced continuously and automatically.

As a result, by combining with the manufacturing process of forming the bi-conical rollers of the bi-conical rollers from the spherical roller material, the production cost can be greatly reduced by the large-scale processing of the bi-conical rollers, which has been impossible in the past. Is realized.

Therefore, it is possible to commercialize a scroll thrust bearing having a double tapered roller as a component, and a scroll type compressor having the thrust bearing structure and having much improved durability as compared with the conventional one. It became.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing a method for manufacturing a double tapered roller according to a first embodiment of the present invention.

FIG. 2 is a front view showing a main part of a centerless grinding machine used in the manufacturing method.

FIG. 3 is a plan view showing a main part of the centerless grinding machine.

FIG. 4 is a side view showing a main part of the centerless grinding machine, viewed from the side of an adjustment wheel.

FIG. 5 is a front view showing a double tapered roller manufactured by the manufacturing method.

FIG. 6 is a schematic explanatory view showing a method for manufacturing a double tapered roller that is Embodiment 2 of the present invention.

FIG. 7 is a schematic explanatory view showing a method for manufacturing a double tapered roller according to Embodiment 3 of the present invention.

FIG. 8 is a view showing a modification of a main part of a centerless grinding machine used in the method of manufacturing a double tapered roller according to the present invention. FIG. 8 (a) is a front view, and FIG. It is the side view seen.

FIG. 9 (a) is a front sectional view showing a scroll type compressor having the double conical rollers as a component, and FIG. 9 (b) is a rolling motion state of the double conical rollers in the scroll type compressor. FIG.

FIG. 10 is a schematic explanatory view showing a method of manufacturing a double tapered roller developed by a test and a research conducted in advance in an intermediate stage leading to the present invention.

FIG. 11 is a front view showing a double conical roller manufactured by the same manufacturing method.

[Explanation of symbols]

W Double conical roller Wa, Wb Double conical surface of double conical roller W ₀ Linear or rod-shaped material W ₁ roller material W ₂ Spherical roller material 1 Cutting machine 3a, 3b Forging die 10 Centerless grinding machine 11 Grinding wheel 11a Grinding wheel of grinding wheel Surface 12 Adjustment wheel 12a Rotation support surface of adjustment wheel 13 Blade 13a Blade support surface 30 Crowning

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Mototsugu Watanabe 2-34, Minamiuematsucho, Yao-shi, Osaka Mitsuhiro Machinery Co., Ltd. F-term (reference) 3C043 AA08 AC04 CC03 3J101 AA12 AA42 AA53 AA62 BA02 BA10 DA01 DA09 DA11 DA12 EA03 FA44 FA60 GA29

Claims (11)

[Claims] 1. A method for manufacturing a double tapered roller, comprising: forming a roller material into a spherical shape; and forming the spherical roller material into a conical surface of the double tapered roller by infeed grinding of a centerless grinding machine. 2. The method for producing double tapered rollers according to claim 1, comprising the following steps. (1) A step of cutting the linear or rod-shaped material into a predetermined size to form the roller material (2) A step of forming the roller material into a spherical shape by forging (3) A heat treatment is performed on the spherical roller material to a predetermined shape. (4) Step of lapping the spherical roller material after heat treatment (5) Applying infeed grinding of a centerless grinding machine to this spherical roller material to form both conical surfaces of both conical rollers (6) The step of superfinishing the conical surfaces of these conical rollers 3. The method for producing a double tapered roller according to claim 1, comprising the following steps. (1) A step of cutting the linear or rod-shaped material into a predetermined size to form the roller material (2) A step of forming the roller material into a spherical shape by forging (3) The spherical roller material is subjected to a centerless grinding machine. Step of performing rough grinding by in-feed grinding (4) Step of subjecting this spherical roller material to heat treatment to obtain a predetermined hardness (5) Applying in-feed grinding of a centerless grinding machine to the spherical roller material after this heat treatment (6) The step of super-finishing the conical surfaces of both conical rollers 4. The method for producing double tapered rollers according to claim 1, comprising the following steps. (1) a step of forming the roller material by cutting a linear or rod-shaped material into a predetermined size; (2) a step of forming the roller material into a spherical shape by forging; (3) a step of forming the forged spherical roller material; A step of performing rough grinding by in-feed grinding of a centerless grinding machine to form a bi-conical surface of the bi-conical roller (4) A step of applying heat treatment to the bi-conical rollers to a predetermined hardness (5) A step of finishing grinding both conical faces of both conical rollers by infeed grinding of a centerless grinder. (6) A step of super-finishing both conical faces of these conical rollers. 5. When forming the conical surfaces of the conical rollers by subjecting the spherical roller material to infeed grinding of a centerless grinder, the conical surfaces are removed while leaving a part of the surface of the spherical roller material. The method for producing a double tapered roller according to any one of claims 1 to 4, wherein the method is performed. 6. The method according to claim 1, wherein the spherical roller material is subjected to in-feed grinding of a centerless grinding machine to form the conical surfaces of the bi-conical rollers, so that the conical surfaces are provided with crowning. The method for producing a double tapered roller according to any one of claims 1 to 5. 7. A grinding wheel having a grinding wheel surface having a profile corresponding to the both conical surfaces of the tapered rollers, an adjusting wheel having a rotation supporting surface having a profile matching the both conical surfaces of the tapered rollers, 7. A blade having a support surface for supporting both conical surfaces of the tapered rollers so that the axis of the grinding wheel and the rotation center axis of the tapered rollers are parallel to each other. The method for producing a double tapered roller according to any one of the first to third aspects. 8. The method according to claim 1, wherein the conical surfaces of the conical rollers rotatably supported at the grinding position are centerlessly ground by infeed without setting a feed angle of the adjusting wheel. 8. The method for producing a double tapered roller according to 7. 9. A double tapered roller manufactured by the method according to claim 1. Description: 10. The double tapered roller according to claim 9, wherein the double tapered roller is used as a rolling element of a scroll thrust bearing. 11. The double tapered roller according to claim 10, wherein the scroll thrust bearing is used as a thrust bearing of a scroll compressor.