JPS6376915A - Bearing box of rotating machinery - Google Patents

Abstract

PURPOSE:To prevent the movement of a bearing by interposing a pre- pressurizing spring between a bearing cover on one side and a bearing housing, so that the difference in expansion between a turning shaft and a motor housing is enabled to be absorbed, and further holding the outer ring of the bearing between two bearing covers. CONSTITUTION:A bearing box is comprised of the first box part 7 which holds the first bearing 5 provided on the load side of a turning shaft 1, and the second box part 8 which holds the second bearing 8 provided on the counterload side of the turning shaft 1. In this case, the second box part 6 is comprised of a bearing housing 81, two bearing covers 82, 83, a fixing means 84 for covers, and a pre-pressurizing spring 85. And when the difference in expansion between the turning shaft 1 and e motor housing 3 is caused, the difference in expansion between 1 and 3 is absorbed by the elastic force of the pre-pressurizing spring 85. Further, the outer ring of the second bearing 6 is held by respective bearing covers 82, 83 in the axial direction, and the movement of the bearing 6 in the radial direction is prevented.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a bearing box for a rotating machine, and more specifically, to a bearing box for holding a first and a second bearing that support a rotating shaft in a rotating machine. This concerns improvements to the box.

[Conventional technology]

A general rotating machine, for example, an electric motor, as shown in Fig. 3,
The rotating shaft 1 is configured to rotate by a rotor 2 attached to the rotating shaft 1 and a stator 4 attached to the inside of a rotating machine housing 3. Both ends of the rotating shaft 1 are rotatably supported by respective bearings 5 and 6, and the respective bearings 5 and 6 are held by a bearing box having first and second box parts 7 and 8.

The first box part 7, as shown in FIGS. 3 and 4,
A bearing housing 71 provided in the rotating machine housing 3 and a bearing cover 72 attached to the bearing housing 71 with bolts 73 are provided. The bearing housing 71 holds the outer ring of the bearing 5 in the axial direction, and the bearing housing 71 fits with the outer ring of the bearing 5, so that the bearing 5
is configured to be fixed in the axial and radial directions.

On the other hand, as shown in FIGS. 3 and 5, the second joint portion 8 is a bearing that is provided in the rotating machine housing 3 and that fits into the outer ring of the bearing 6 on the other end side, which is the anti-load side of the rotating shaft 1. It is composed of a housing, and a gap 12 is formed between it and the bearing 6 along the axial direction. When the rotating shaft 1 and the rotating machine housing expand and extend in the axial direction due to temperature rise due to the operation of the electric motor, a difference occurs in the extension of the two, so the gap 12 provided between the bearing 6 and the rotating shaft 1 causes a difference in the extension. We try to absorb the differences between the two.

Alternatively, as shown in FIG. 5, the second joint portion 8 includes a bearing housing 8a having a ring 8b fitted to the outer periphery of the bearing 6, and a bearing cover 8d attached to the bearing housing 8a with bolts 8c. and a preload spring 8e interposed along the axial direction in the gap 12 between the bearing housing 8a and the outer ring of the bearing 6. The elastic force of the preload spring 8e absorbs the difference in elongation, and the bearing 6 I am trying to suppress the movement of.

Incidentally, a related known example of this type is Utility Model Application No. 52-
Publication No. 39127 and the like can be mentioned.

[Problem that the invention seeks to solve]

As described above, in the prior art shown in FIGS. 3 and 4, the gap 12 is provided in order to absorb the difference in length between the rotating shaft 1 and the rotating machine housing 3.

However, if there is a gap 12, in addition to this gap, the second
Since there is also a gap due to the fitting tolerance between the joint 8 and the second bearing 6, the bearing 6 vibrates within the second joint 8, which causes the second joint 8 and the bearing 6 to wear out. There is.

Furthermore, in the prior art shown in FIG. 5, although the movement of the bearing 6 and the bearing housing 8a is suppressed by the preload spring 8e, the movement cannot be completely suppressed, and therefore the spring force of the preload spring 8e is When tightened, the bearing housing 8
There is a risk that the load applied to a and the bearing 6 will be excessive, and the lifespan of both will be shortened.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a bearing box for a rotating machine that can prevent vibration and wear and extend its life.

[Means for solving problems]

In the present invention, the first . The first bearing holds the second bearing.
．． In a bearing box having a second joint, the first joint fixing the first bearing in the axial and radial directions, the second joint is fitted into the outer ring of the second bearing. a second bearing housing disposed on both sides of the bearing housing;
two bearing covers capable of holding the outer ring of the bearing along the axial direction, fixing means for inserting the bearing housing and attaching the bearing cover to the bearing housing, one of the two bearing covers and the bearing housing. The rotating shaft 1 and the rotating machine housing extend in the axial direction due to the heat generated by the operation of the right-handed rotating machine.
Although there is a difference in elongation between the two, since a preload spring is interposed between one of the bearing covers and the bearing housing, the elastic force of the preload spring can absorb the difference in elongation between the rotating shaft and the motor housing.

In addition, since the outer ring of the bearing is directly sandwiched between the two bearing covers along the axial direction, it is possible to prevent the bearing from moving in the radial direction even if there is a gap due to the fitting tolerance between the bearing and the bearing housing. can.

Therefore, as a result of the vibration of the bearing being eliminated, it is possible to prevent the bearing box from being worn out by the bearing, thereby extending the life of the bearing box and increasing its reliability.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a sectional view of an electric motor showing an embodiment to which the present invention is applied, and FIG. 2 is an enlarged view of section A in FIG.

In the electric motor shown in FIG. 1, both ends of the rotating shaft 1 have first and second
is supported by bearings 5 and 6, and the first. A second bearing 6 is held in a bearing box (not numbered).

The bearing box holds a first joint 7 that holds a first bearing 5 provided on the load side of the rotating shaft 1, and a second bearing 6 provided on the opposite load side of the rotating shaft 1. It is configured to include a first box part 8.

The first box part 7 includes a bearing bracket 71 attached to one end of the motor housing 3 and fitted with the outer ring of the first bearing 5, and a bearing cover 12 attached to the bearing bracket 71 with bolts 73. The first bearing 5 is fixed in the radial and axial directions by sandwiching the outer ring of the first bearing 5 between the bearing cover 72 and the bearing bracket 71 in the axial direction.

On the other hand, as shown in an enlarged view in FIG. 2, the second box part 8 includes a bearing housing 81 and two bearing covers 82.
83, a cover fixing means 84, and a preload spring 85.

The bearing housing 81 is attached to the other end of the motor housing 3 and has a ridge 81 formed in the circumferential direction on the inside.
a, and a ring 81b whose outer peripheral side is fitted into the arm 81a and which has an inner diameter approximately the same size as the outer ring diameter of the second bearing 6 and approximately the same width as the width of the second bearing 6. The outer ring of the bearing 6 is fitted inside the ring 81b.

The two bearing covers 82 and 83 are attached to the bearing housing 8.
1, and an inner cover 83, which is provided with a seal member 86 through which the rotating shaft 1 is inserted and is located inside the bearing housing 81, and is arranged on both sides of the bearing housing 81. ing.

Clamping protrusions 82a and 83a are formed on each of the outer and inner covers 82 and 83 at positions corresponding to the outer ring of the second bearing 6. It is designed so that it can be held.

The fixing means 84 for the cover is composed of a bolt, and its tip end is screwed from the outer cover 82 to the inner cover 83, so that the cover is inserted through the bearing housing 81 and attached to the outer cover 82, the inner cover 82. 83 is installed.

Although the preload spring 85 is interposed between the outer cover 82 and the bearing housing 81 in the illustrated example, it may be interposed between the bearing housing 81 and the inner cover, and in any case, the preload spring 85 has an elastic force in the axial direction. There is.

Next, the function of the bearing box of the embodiment will be described. 4 The rotating shaft 1 and motor housing 3 are damaged due to heat generated by the operation of the electric motor.
extends in the axial direction, and there is a difference in extension between the two. However, since the preload spring 85 is interposed between the bearing cover 82 and the bearing housing 81, the difference in elongation between the rotating shaft 1 and the motor housing 3 can be absorbed by the elastic force of the preload spring 85.

Furthermore, since the outer ring of the second bearing 6 is directly sandwiched between the bearing covers 82 and 83 along the axial direction, even if there is a gap due to the fitting tolerance between the bearing 6 and the bearing housing 81, the bearing 6 can be radial movement can be prevented.

[Effects of the Invention] As described above, the present invention is configured to not only absorb the difference in elongation between the rotating shaft 1 and the motor housing, but also to prevent the bearing from moving in the radial direction. Therefore, as a result of the bearing not vibrating, the bearing box can be prevented from being worn out, which has the effect of prolonging its life and improving reliability.

[Brief explanation of the drawing]

Fig. 1 is an upper half sectional view of an embodiment in which the present invention is applied to an electric motor, Fig. 2 is an enlarged view of part A in Fig. 1, and Fig. 3 is an upper half sectional view showing an electric motor using a conventional bearing box. FIG. 4 is an enlarged view showing a conventional example of a bearing box, and FIG. 5 is an enlarged view showing another example of a conventional bearing box. 5... First bearing, 6... Second bearing, 7... First box part, 8... Second box part, 81... Bearing housing, 82° 83... - Bearing cover, 84...fixing means for cover, 85...preload spring. Agent Patent Attorney Tadashi Akimoto Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. First and second bearings that respectively hold the first and second bearings of the rotating machine
In the bearing box, the first box part is attached to the rotary machine housing and the second bearing box is attached to the rotating machine housing. a bearing housing that fits into the outer ring of the second bearing; two bearing covers that are placed on both sides of the bearing housing and can axially sandwich the outer ring of the second bearing; and a preload spring interposed between one of the at least two bearing covers and the bearing housing and having an elastic force in the axial direction. Bearing box for rotating machines.