JPH06159378A - Shaft fitting portion - Google Patents

Abstract

PURPOSE:To realize easy fitting by giving desired surface pressure and also realize simple opening. CONSTITUTION:This portion is equipped with inside wedge materials 5 whose inner peripheral surface come into contact with a rotary shaft 2 and whose outer peripheral surfaces are formed into inclination surfaces inclined axially; an outside wedge material 6 of a cylindrical outer surface at whose inner peripheral surface an inclination surface contacting the inclination surfaces of these inside wedge materials 5 is formed; a rotary body boss portion 3 which has an inner peripheral surface contacting the cylindrical outer surface of the outside wedge material 6 and where an end surface to catch the end surface of the inside wedge materials 5 is formed; and tightening means 7 to conduct tightening by drawing the outside wedge material 6 into the inner peripheral surface inside of the rotary body boss portion 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure in which a boss portion of a rotating body that rotates with a rotating shaft such as a pump impeller or a turbine rotor is fitted to the rotating shaft.

[0002]

2. Description of the Related Art FIG. 5 shows a shaft fitting portion of a conventional straight shaft, (B) a hollow shaft, (C) a stepped shaft, and (D) an overhang shaft. At the fitting portion between the rotating shaft 2 and the rotating body boss portion 3, the inner diameter of the rotating body boss portion 3 is precisely formed to a diameter smaller than the outer diameter of the rotating shaft 2 by a predetermined minute dimension, and press fitting and shrink fitting are performed. , Fix it with a tight fit by a means such as a cold fit. There are also fitting means such as keys and serrations, but if cutting the groove or the like on the rotary shaft 2 is unfavorable in terms of strength, etc., the fitting means by means of the aforementioned interference fit is used.

[0003]

Although the conventional shaft fitting portion is as described above, it is extremely difficult to open the interference fit once it is fitted. Further, it is very difficult to press-fit, shrink fit, or cool fit by precisely forming the inner diameter of the rotating body boss portion 3 smaller than the outer diameter of the rotating shaft 2 by a predetermined minute dimension. And quick work is required. Further, since it is impossible to form the rotating shaft 2 and the rotating body boss portion 3 into a completely ideal shape, the fitting surface pressure often does not reach an appropriate value, and the value of the fitting surface pressure is known. Is also difficult. If the fitting surface pressure is insufficient, slippage occurs, and if the fitting surface pressure is excessive, internal stress, strain, cracks, etc. occur. Further, there is a problem that the fitting surface pressure distribution of the finished product is non-uniform, and a tightly fitted portion and a loosely fitted portion are generated, and as shown in FIG. 4, minute cracks (fretting) occur. there were.

The present invention has been made to solve the above-mentioned problems, and the shaft fitting portion can be easily fitted by adjusting the fitting surface pressure arbitrarily and the fitting portion can be easily opened. Aim to get.

[0005]

In the shaft fitting portion according to the present invention, an inner wedge member having an inner peripheral surface in contact with a rotation shaft and an outer peripheral surface formed as an inclined surface inclined in the axial direction, and the inner wedge member. An outer wedge member having a cylindrical outer surface whose inclined surface in contact with the inclined surface is formed on the inner peripheral surface, and an end surface having an inner peripheral surface in contact with the cylindrical outer surface of the outer wedge member and receiving the end surface of the inner wedge member And a fastening means for drawing in and tightening the outer wedge member in the inner peripheral surface of the rotor boss portion.

[0006]

According to the present invention, the rotary shaft is passed through the rotary body boss portion, and the inner wedge material is applied to the outer peripheral surface of the rotary shaft and the end surface for receiving the end surface of the inner wedge material of the rotary body boss portion, and the inner wedge material and the rotary body boss portion. Insert the outer wedge material between the
When the outer wedge is pulled into the boss of the rotating body by the fastening means, the inclined surfaces of both wedges come into contact with each other, and the force is the ratio of the cotangent of the inclination angle of the inclined surface to the axial force. Occurs in the radial direction, and the rotary body boss portion is fitted to the rotary shaft via the outer wedge member and the inner wedge member. Therefore, by adjusting and setting the force applied to the fastening means,
The fitting can be performed with a desired fitting surface pressure. Further, by loosening and removing the fastening means, both wedge members can be easily removed and opened.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 2 is a rotary shaft, and 3 is a boss portion of a rotating body such as a pump impeller or a turbine rotor to be fitted on the rotary shaft 2. Further, 5 is an inner wedge member, 6 is an outer wedge member, and 7 is a tightening bolt. The inner diameter portion of the rotary body boss portion 3 into which the rotary shaft 2 is fitted is formed so as to have a slight gap on the outer surface of the rotary shaft 2 in the left portion of FIG. It is formed into a shape.
Further, in the figure, four bolt holes are formed in the rotary body boss portion 3, and a portion for receiving the head of the bolt is also formed. Further, an end face for receiving the inner wedge member 5 is formed at the right end portion of the left portion in the drawing of the inner diameter portion of the rotating body boss portion 3 near the rotation shaft 2.

In FIG. 1, the inner wedge member 5 is formed in such a shape that its inner peripheral surface is in contact with the outer peripheral surface of the rotary shaft 2, and the outer peripheral surface of the inner wedge member 5 is slanted in the axial direction in a laterally conical shape. It is formed on the inclined surface 5s. The inner wedge member 5 is divided by a dividing line in the axial direction, and is divided into three in the figure.
As shown in FIG. 1 (B), the inner wedge member 5 is in the mounted state.
It is formed so that a slight gap remains between the divided surfaces. The outer wedge member 6 is formed on the inclined surface 6s having the same inclination angle, the inner peripheral surface of which is in contact with the inclined surface 5s of the outer peripheral surface of the inner wedge member 5, and the outer peripheral surface of the outer wedge member 6 is on the right side of the rotary body boss portion 3. The portion is formed in a shape in contact with a cylindrical inner surface having a large inner diameter. Although the outer wedge member 6 is integrated in the figure,
If it is integrated, it may be difficult to insert it unless it is precisely formed, or it may rattle, so that it may be divided by an axial dividing line in order to facilitate manufacturing. Further, the outer wedge member 6 is formed with a screw hole into which the tightening bolt 7 is screwed in the axial direction. The screw hole of the outer wedge member 6 and the bolt hole of the rotary body boss portion 3 are formed on the same line. The tightening bolt 7 is made of the outer wedge material 6
Have a shape and strength sufficient to draw the into the boss portion 3 of the rotating body. The materials of the inner wedge member 5 and the outer wedge member 6 can be arbitrarily selected, and, for example, a tough material having good elastic deformation can be adopted so as not to cause fretting wear on the rotary shaft 2.

Next, the operation of the embodiment shown in FIG. 1 will be described. In order to fit and fix the rotary body boss portion 3 to the rotary shaft 2, first, the rotary shaft 2 is passed through the rotary body boss portion 3, and the relative position between the rotary body boss portion 3 and the rotary shaft 2 is temporarily fixed as a predetermined position. To do. Next, insert the inner wedge member 5 into the outer peripheral surface of the rotating shaft 2 by inserting the inner wedge member 5 from the cylindrical portion having the larger inner diameter of the rotary body boss portion 3 first, with the end portion having the larger wall thickness of the inner wedge member 5 inserted. Also, the inner wedge member at the inner side of the rotary body boss portion 3 is temporarily fixed by being applied to the end face that receives the end face. next,
The inclined surface 5s on the outer peripheral surface of the inner wedge member 5 and the rotary body boss portion 3
The outer wedge member 6 is inserted between the inner peripheral surface and the cylindrical inner peripheral surface of the inner peripheral surface. Next, the tightening bolt 7 is inserted into the bolt hole of the rotary body boss portion 3 from the opposite side of the rotary body boss portion 3 (the left side in FIG. 1A), and the tightening bolt 7 is screwed into the screw hole of the outer wedge member 6. . When the head of the tightening bolt 7 hits the hole end of the rotary body boss portion 3, the tightening bolt 7 is screwed to pull the outer wedge member 6 into the large-diameter cylindrical portion of the rotary body boss portion 3. When the outer wedge member 6 advances to the left in the figure, and the inclined surface 6s of the inner peripheral surface of the outer wedge member 6 comes into contact with the inclined surface 5s of the outer peripheral surface of the inner wedge member 5, the left side of the outer wedge member 6 The slanted surface 6s of the outer wedge member 6 presses the slanted surface 5s of the inner wedge member 5 toward the inner diameter side, and the outer wedge member 6 is pushed toward the outer diameter side from the inner wedge member 5 by its reaction. Due to the contact pressure, the rotary body boss portion 3 is fixed to the rotary shaft 2 via the outer wedge member 6 and the inner wedge member 5.

In contrast to the force applied in the axial direction by screwing in the tightening bolt 7, the force generated in the radial direction by the wedge action is the ratio of the cotangent of the inclination angles of the inclined surfaces 5s and 6s. Becomes For example, when the inclination angles of the inclined surfaces 5s and 6s are 8 degrees, the cotangent is about 7, and a force about 7 times the axial force acts in the radial direction. That is, in this example, the rotating body boss portion 3 has a fitting pressure that is about seven times the tightening force of the tightening bolt 7, and the rotating shaft 2
Will be fitted to. The screwdriver force applied to the tightening bolt 7 can be arbitrarily adjusted and set with a torque wrench, and the pulling force of the tightening bolt 7 is immediately known from the value, which means that a fitting pressure 7 times that force is applied. Therefore, the fitting pressure can be easily adjusted and set easily. It should be noted that if the inclination angle of the inclined surfaces 5s and 6s is made small, the cotangent of that angle will suddenly increase, so that a very large fitting surface pressure can be obtained.

When the shaft fitting portion is opened, if the tightening bolt 7 is unscrewed and removed, the outer wedge member 6 can be immediately withdrawn and the inner wedge member 5 can be removed. It can be easily extracted from 3 and opened.

Next, a second embodiment shown in FIG. 2 will be described. In FIG. 2, the tightening bolt 7 is a bolt having an ordinary shape, and the nut 8 is screwed in to be tightened. Therefore, although the screw holes are formed in the holes of the outer wedge member 6 in FIG. 1, the holes of the outer wedge member 6 through which the tightening bolts 7 are passed may be simple holes in FIG. With this structure, the number of parts is increased, but the shape of the hole formed in the outer wedge member 6 and the rotary body boss portion 3 is simplified, and the shapes of the tightening bolt 7 and nut 8 are also ordinary shapes, which facilitates manufacturing. . Further, the fitting area can be made larger than that in FIG. However, there is a disadvantage that the head of the bolt 7 and the nut 8 project.

Next, a third embodiment shown in FIG. 3 will be described. In the above embodiment, the wedge material is a set of the inner wedge material 5 and the outer wedge material 6, but in FIG. 3, only the wedge material 5 is used. The wedge member 5 has a cylindrical shape whose inner peripheral surface is in contact with the outer surface of the rotary shaft 2 and whose outer peripheral surface is an inclined surface 5s inclined in the axial direction. An inclined surface 3s corresponding to the inclined surface 5s of the wedge member 5 is formed on the inner peripheral surface of the rotary body boss portion 3. The wedge member 5 is appropriately divided by a dividing line in the axial direction. The tightening bolt 7 and nut 8 are shown in FIG.
Although it is similar to that shown in FIG. 1, it may be shown in FIG. This embodiment has the advantage that the structure is simple.

In the embodiment shown in FIG. 1, four tightening bolts 7 are provided, but six or eight tightening bolts may be provided as required. Further, the outer wedge member 6 is not integrated so that it is divided by an axial dividing line or the outer wedge member 6 is integrated so as not to require accuracy in manufacturing dimensions.
It is also possible to cut an axial slit at a position to facilitate the radial deformation of the outer wedge member 6. Further, although the inner wedge member 5 is divided into three, it may be divided into two or four.

[0015]

As described above, according to the present invention, a wedge member is inserted between the rotary shaft and the boss portion of the rotary body and tightened in the axial direction, and the wedge action generates a fitting surface pressure in the radial direction. Since this is done, the fitting can be carried out very easily, and a desired fitting surface pressure can be generated. Further, the shaft fitting portion can be easily opened.

[Brief description of drawings]

FIG. 1 shows a shaft fitting portion according to an embodiment of the present invention,
(A) is a longitudinal sectional view and (B) is a right end view of (A).

FIG. 2 is a semi-longitudinal sectional view of a shaft fitting portion according to a second embodiment of the present invention.

FIG. 3 is a semi-longitudinal sectional view of a shaft fitting portion according to a third embodiment of the present invention.

FIG. 4 is a diagram showing a crack generation state of a shaft fitting portion.

[FIG. 5] Conventional (A) is a straight shaft, (B) is a hollow shaft,
(C) is a stepped shaft, (D) is a longitudinal cross-sectional view showing a shaft fitting portion of the overhang shaft.

[Explanation of symbols]

2: rotating shaft, 3: boss of rotating body, 5: inner wedge material,
5s: inclined surface, 6: outer wedge material, 6s: inclined surface,
7: Tightening bolt, 8: Nut.

Claims (2)

[Claims] 1. An inner wedge member having an inner peripheral surface in contact with a rotating shaft and an outer peripheral surface having an inclined surface inclined in an axial direction, and an inclined surface in contact with the inclined surface of the inner wedge member formed in the inner peripheral surface. An outer wedge member having a cylindrical outer surface, an inner peripheral surface contacting the outer cylindrical member of the outer wedge member, and an end face for receiving the end face of the inner wedge member, and a rotor boss. And a fastening means for pulling in and tightening the outer wedge member in the inner peripheral surface of the shaft fitting portion. 2. A wedge member, the inner peripheral surface of which is in contact with the rotating shaft, and the outer peripheral surface of which is formed into an inclined surface that is inclined in the axial direction, and an inclined surface which is in contact with the inclined surface of the wedge member is formed into the inner peripheral surface. A shaft fitting portion, comprising: a rotary body boss portion; and a fastening means for pulling and tightening the wedge member in the inner peripheral surface of the rotary body boss portion.