JP2011241942A - Device for mounting rotor to rotary shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce outbreaks of a bend of a mounting shaft to be caused by a machining error of a stepped surface in a mounting device wherein a mounting shaft 12, which is formed with a stepped 15 small-diameter, is integrally formed with an end of a rotary shaft 11 and a rotor 13 fitted on the mounting shaft is fastened in the axial direction of the mounting shaft by a fastener 14, which is screwed to the front end of the mounting shaft, so that a side surface 13a of the rotor abuts on the step surface 15.SOLUTION: The step surface 15 is formed into a spherical surface protruding toward the rotor 13 or into a conical surface protruding toward the rotor 13.

Description

  The present invention relates to an apparatus for attaching a rotating body such as an impeller or a gear to a rotating shaft.

  Conventionally, when a rotating body such as an impeller is attached to a rotating shaft, for example, as described in Patent Documents 1 and 2 and the like, as shown in FIGS. A mounting shaft 2 having a smaller shaft diameter in a stepped shape is integrally provided, and the rotating body 3 is fitted on the mounting shaft 2, and the rotating body 3 is screwed onto the tip of the mounting shaft 2. 4 (FIG. 7) or a screw type fastening body of a bolt 4 ′ (FIG. 8), one side surface 3a of the rotating body 3 becomes a stepped surface 5 from the rotating shaft 1 to the small-diameter mounting shaft 2. The structure of tightening in the axial direction of the mounting shaft 2 is employed so as to contact.

JP 10-339331 A JP 2006009634 A

  However, the conventional rotating body mounting apparatus has a problem that the mounting shaft is bent and deformed with respect to the rotating shaft, as described below.

  That is, when the rotating shaft 1 integrally provided with the mounting shaft 2 is manufactured, the stepped surface 5 from the rotating shaft 1 to the mounting shaft 2 has an axis line of the rotating shaft 1 as shown in FIG. There may be a case where a machining error of tilting by a minute angle Δθ with respect to a plane perpendicular to 1a occurs.

  When such a tilting processing error occurs, one side of the rotating body 3 fitted on the mounting shaft 2 and the stepped surface 5 is sandwiched between one side surface 3a and the stepped surface 5 on one side. In other words, the gap δ can be formed only in the portion with the low inclination.

  In this state, the rotating body 3 is tightened in the axial direction by a fastening body such as a nut 4 (or bolt 4 '), so that the mounting shaft 2 is fitted to the rotating body. Since a bending moment is generated in the direction in which the gap δ on one side between the side surface 3a of the body 3 and the stepped surface 5 is eliminated, the mounting shaft 2 is shown by a two-dot chain line in FIG. As shown, the axis 1a of the rotary shaft 1 is bent and deformed.

  This invention makes it a technical subject to reduce reliably this problem, ie, the bending resulting from the processing error of the said stepped surface in the said attachment shaft.

In order to achieve this technical problem, claim 1
“With one end of the rotating shaft integrally provided with a mounting shaft having a stepped small diameter from the rotating shaft, a rotating body fitted on the mounting shaft is screwed to the tip of the mounting shaft, In the mounting device configured to be tightened in the axial direction of the mounting shaft so that one side surface of the rotating body contacts the stepped surface,
The stepped surface is formed as a spherical surface that is convex toward the rotating body, or is formed as a conical surface that is convex toward the rotating body. "
It is characterized by that.

Claim 2
“A part of one of the side surfaces of the rotating body that contacts the stepped surface is formed as a concave spherical surface with respect to the rotating body, and a radius of the concave spherical surface is defined. Is made larger than the radius of the convex spherical surface on the stepped surface, or a concave conical surface is formed with respect to the rotating body, and the conical angle of the concave conical surface is made convex on the stepped surface. Make it larger than the cone angle of the conical surface. "
It is characterized by that.

  A small clearance is provided between the shaft diameter of the mounting shaft integrated with the rotating shaft and the hole diameter of the rotating body fitted on the mounting shaft to facilitate fitting of the rotating body onto the mounting shaft. As is well known, according to this, the rotating body fitted on the mounting shaft can be displaced in the direction perpendicular to the axis by the clearance between the hole diameter and the shaft diameter of the mounting shaft. it can.

  Therefore, in the present invention, on the assumption of this, the configuration described in claim 1 is adopted.

  According to this configuration, when there is a machining error in the stepped surface from the rotating shaft to the mounting shaft that the stepped surface is inclined by a minute angle with respect to the surface perpendicular to the axis of the rotating shaft, Even if a gap is formed on one side of the rotating body between the one side surface of the rotating body and the stepped surface, ie, a portion having a low inclination, due to an inclination machining error, By shifting the rotating body in a direction perpendicular to the axis by the clearance between the hole diameter and the shaft diameter of the mounting shaft, a highly inclined portion of the convex spherical surface or conical stepped surface is rotated. Since it fits in the hole diameter in a body, it aligns so that the clearance gap in the said one side may become narrow.

  Thus, the mounting shaft of the rotating shaft can be reliably reduced from being bent and deformed with respect to the rotating shaft when the rotating body fitted on the rotating shaft is fastened in the direction of the axis by the fastening body.

  According to a second aspect of the present invention, the concave spherical surface or the conical surface on the side surface of the rotating body is a part of the stepped surface that forms the convex spherical surface or the conical shape within the hole diameter of the rotating body. Since it is guided to the alignment to be fitted, the labor required for mounting the rotating body can be further reduced.

It is a vertical front view which shows 1st Embodiment in this invention. It is a vertical front view which shows the state before fastening in 1st Embodiment. It is an exploded view in a 1st embodiment. It is an enlarged view of the principal part in 1st Embodiment. It is an enlarged view of the principal part in 2nd Embodiment. It is an enlarged view of the principal part in 3rd Embodiment. It is a vertical front view which shows a prior art example. It is a vertical front view which shows another prior art example. It is an enlarged view of the principal part in a prior art example.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  1 to 4 show a first embodiment.

  In these drawings, reference numeral 11 denotes a rotating shaft that directly connects the exhaust turbine and the compression blower in the exhaust turbocharger.

  One end of the rotary shaft 11 is integrally provided with a mounting shaft 12 having a shaft diameter D smaller than the shaft diameter D0 of the rotating shaft 11, and the exhaust turbocharger is attached to the mounting shaft 12. The impeller 13 in the compression blower is fitted, and the impeller 13 is screwed into the tip of the mounting shaft 12 with a nut 14 or a fastening member such as a screw type screw, etc., on one side surface of the impeller 13. The impeller 13 is attached to the rotary shaft 11 by tightening in the axial direction of the mounting shaft 12 so that 13a contacts the stepped surface 15 from the rotary shaft 11 to the mounting shaft 12.

  In order to facilitate the fitting of the impeller 13 to the mounting shaft 12, the hole diameter d of the impeller 13 and the shaft diameter D of the mounting shaft 12 to which the impeller 13 is fitted are small. Clearance is provided.

  A stepped surface 15 from the rotary shaft 11 to the mounting shaft 12 having a small shaft diameter D is formed into a spherical surface having a radius R having a center point O on the axis 11 a of the rotary shaft 11. The surface is convex toward the impeller 13.

  According to this configuration, the center point O ′ on the spherical surface of the stepped surface 15 from the rotating shaft 11 to the mounting shaft 12 is very small from the axis 11 a of the rotating shaft 11 as shown in FIG. When there is a machining error that the stepped surface 15 is inclined by a minute angle Δθ with respect to a plane perpendicular to the axis 11a of the rotary shaft 11 due to the deviation by the dimension E, the processing error of this inclination is As a result, a minute gap δ is formed on one side of the impeller 13 between the one side surface 13a and the stepped surface 15 with the axis 11a of the rotating shaft 11 interposed therebetween, that is, a portion with a low inclination.

  Therefore, as shown in FIG. 4B, the impeller 13 is displaced in a direction perpendicular to the axis 11a by the clearance between the hole diameter d and the shaft diameter D of the mounting shaft 13, thereby making the convex type Of the stepped surface 15 having a spherical surface, a highly inclined portion is fitted into the hole diameter d of the impeller 13, and therefore the centering is performed so that the gap δ on one side is narrowed.

  As a result, the mounting shaft 12 of the rotating shaft 11 is bent and deformed with respect to the rotating shaft 11 when the impeller 13 fitted to the rotating shaft 11 is tightened in the direction of the axis 11a with a fastening body such as a nut 14 or a bolt. Can be reliably reduced.

  When the impeller 13 is tightened in the axial direction by a screw-type fastening body such as a nut 14 (or bolt), the opening corner 13b of the impeller 13 to the side surface 13a of the hole diameter d is shown in FIG. As described above, it is preferable to partially plastically deform (permanently deform), thereby reducing looseness in the screw-type fastening body (the same applies to the following embodiments).

  Next, FIG. 5 shows a second embodiment.

  In this second embodiment, instead of forming the stepped surface 15 from the rotating shaft 11 to the mounting shaft 12 into a spherical surface, as shown in FIG. The other configuration is the same as that of the first embodiment.

  As described above, even when the stepped surface 15 is formed as a convex conical surface, as shown in FIG. 5 (B), the step 15 is minute with respect to a surface perpendicular to the axis 11a of the rotating shaft 11. There may be a processing error of tilting by a certain angle Δθ.

  Also in this case, the stepped surface having the convex conical shape is formed by shifting the impeller 13 in the direction perpendicular to the axis 11a by the clearance of the hole diameter d and the shaft diameter D of the mounting shaft 13. 15, a portion with a high inclination is fitted into a hole diameter d in the impeller 13, and the gap on the one side is aligned so that the gap is narrowed. Therefore, the impeller 13 is fastened with a nut 14 or a bolt. When the body is tightened in the direction of the axis 11a, the mounting shaft 12 can be reliably reduced from being bent and deformed with respect to the rotating shaft 11.

  6A and 6B show a third embodiment.

  In the third embodiment, a portion of one side surface 13a of the impeller 13 that comes into contact with the stepped surface 15 has a concave spherical shape with respect to the impeller 13, as shown in FIG. The concave spherical surface 16 is formed on the surface 16 so that the radius R0 of the concave spherical surface 16 is larger than the radius R of the convex spherical surface of the stepped surface 15. The other configurations are the same as those of the first embodiment. It is the same.

  According to this configuration, the concave spherical surface 16 on the side surface 13a of the impeller 13 is a stepped surface in which the impeller 13 is formed into the convex spherical surface within the hole diameter d as shown in FIG. Since it is guided to the alignment that a part of 15 is fitted, the labor required for mounting the impeller 13 can be further reduced.

  In the third embodiment, the concave spherical surface 16 on the side surface 13a of the impeller 13 can be formed as a concave conical surface. In this case, the conical surface of the concave conical surface is made larger than the conical angle θ of the convex conical surface of the stepped surface 15, so that the concave conical surface is similar to the concave spherical surface 16. The impeller 13 is guided to an alignment in which a part of the stepped surface 15 having the convex conical surface is fitted in the hole diameter d.

  In each of the above-described embodiments, in the exhaust turbocharger, the impeller in the compression blower is attached to the rotating shaft of the exhaust turbocharger. However, the present invention is not limited to this. Of course, the present invention can also be applied to a case where a rotating body such as a power transmission ring body such as a gear is mounted.

11 Rotating shaft 11a Axis of rotating shaft 12 Mounting shaft 13 Impeller (Rotating body)
13a Side surface of impeller 14 Nut 15 Stepped surface 16 Concave spherical surface

Claims (2)

An attachment shaft having a stepped diameter smaller than that of the rotation shaft is integrally provided at one end of the rotation shaft, and the rotating body fitted on the attachment shaft is screwed to the tip of the attachment shaft by the fastening body. In the mounting device configured to be tightened in the axial direction of the mounting shaft so that one side surface of the rotating body contacts the stepped surface,
The stepped surface is formed as a spherical surface that is convex toward the rotating body, or is formed as a conical surface that is convex toward the rotating body. Mounting equipment.   The portion of one of the side surfaces of the rotating body that contacts the stepped surface is formed as a concave spherical surface with respect to the rotating body, and a radius of the concave spherical surface is set. It is larger than the radius of the convex spherical surface on the stepped surface, or is formed in a concave conical surface with respect to the rotating body, and the conical angle of the concave conical surface is set to a convex cone on the stepped surface. An apparatus for attaching a rotating body to a rotating shaft, wherein the rotating body is larger than a cone angle of a surface.

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