JPH04171315A - Automatic aligning type journal bearing - Google Patents

Abstract

PURPOSE:To reduce frictional resistance moment by a large margin by providing a supporting seat that stretches out in a direction perpendicular to a shaft and having a cylindrical section on both side faces nearby the center of the axial length of a bearing shell, and a bearing stand that supports the supporting seat. CONSTITUTION:In an automatic aligning type journal bearing, a supporting seat 5 that stretches out horizontally and in a direction perpendicular to a shaft 1 on both side faces nearby the center of the axial length of a bearing shell 2 composed of an upper half part 2a and a lower half part 2b when divided into two parts and having a cylindrical section, and a bearing stand 6 that supports this supporting seat 5 are provided. At the time of machining the supporting seat 5, after the supporting seat is machined to a cylindrical shape keeping the bearing shell 2 in a body, the bearing shell is divided into upper and lower two parts. Since bearing load is supported by the cylindrical supporting seat having a short turning radius, frictional resistance moment that acts on the bearing when it is in motion is reduced by a large margin. Therefore, the supporting seat is forced to follow up vertical axial eccentricity to perform automatic aligning by means of this cylindrical supporting seat.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a self-aligning journal bearing that supports a rotating electrical machine with a horizontal shaft and has a self-aligning function.

[Conventional technology]

Bearings that support a rotating shaft through sliding friction are called journal bearings, and bearings that have a self-aligning structure for reasons of rigidity on the bearing stand during installation or operation are called self-aligning journal bearings. Self-aligning journal bearings are used in horizontal-shaft water turbine generators, etc., where the shaft twist is large. FIG. 5 is a perspective view showing a part of a conventional self-aligning journal bearing. In Fig. 5, the self-aligning journal bearing has an upper and lower half structure consisting of an upper half 2a and a lower half 2b, and contacts the shaft 1, and has a spherical surface on the outer diameter side near the center of the axial length. It consists of a bearing shell 2 having a support seat 3 and a bearing stand 4 supporting the support seat 3. When the shaft is eccentric in the vertical direction during operation, the spherical support seat 3 slides on the surface of the bearing stand 4 to follow the eccentricity of the shaft l for alignment.

[Problem to be solved by the invention]

The sixth circle is an explanatory diagram showing the frictional resistance moment of the self-aligning journal bearing of FIG. 5. In the self-aligning type journal bearing of the suspension shown in Fig. 5, the position of the bearing pedestal 4 is determined at the time of installation without any load being applied to the bearing, and then the shaft 1 is gently moved to the upper half 2b of the bearing shell 2. , the frictional resistance moment Mo applied to the support seat is dominated by the weight of the bearing shell 2 and is extremely small. The load during installation is P. , the load during operation is Pl, the weight of the bearing shaft is WQ, the weight of the shaft is W, the low frictional resistance moment M at Pg acting on the bearing pedestal (1:00), the frictional resistance during operation acting on the bearing pedestal. The moment is M. If the radius of rotation acting on the bearing stand is Ro, then Po = W
o M,=W6 xR. PI −wo +w M,= (we 7w
） Therefore, the frictional resistance moment M1 increases significantly. As a result, the journal bearing is operated without its self-aligning function being fulfilled, and there is a risk that the bearing will eventually burn out. F is a frictional force acting on the contact surface between the support seat 3 and the bearing stand 4. SUMMARY OF THE INVENTION An object of the present invention is to provide a self-aligning journal bearing that reliably exhibits a self-aligning function even under a bearing load.

[Means to solve the problem]

According to the invention of claim 1, the above object is achieved by providing a bearing shell having an upper and lower halves, which contacts the shaft and having a curved support seat on the outer diameter side near the center of the length in the axial direction; A self-aligning journal bearing comprising a bearing stand supporting the bearing shell, a support seat having a cylindrical cross section and extending in a direction perpendicular to the axis on both sides near the center of the axial length of the bearing shell;
This is achieved by providing a bearing stand that supports this support seat. According to the invention of claim 2, the above-mentioned object is to provide a bearing shell having an upper and lower half-split structure that contacts the shaft and has a curved support seat on the outer diameter side near the center of the axial length; In a self-aligning journal bearing consisting of a bearing stand that supports the
The bearing is provided with a support seat that extends in a direction perpendicular to the axis on both sides near the center of the axial length of the upper half of the shell and has a semi-cylindrical cross section, and a bearing stand that supports the support seat. achieved by

[For use]

According to claim 1, the present invention is provided with a support seat that extends in a direction perpendicular to the axis on both sides of a bearing shell and has a cylindrical cross section, and a bearing stand that supports this support seat, so that the bearing load is reduced to a radius of rotation. Since the bearing is supported by a short cylindrical support seat, the moment of frictional resistance acting on the bearing during operation is significantly reduced. Therefore, this cylindrical support seat allows the support seat to follow up and down eccentricity in the axial direction for automatic alignment. According to a second aspect of the present invention, a support seat having a semi-cylindrical cross section and extending in a direction perpendicular to the axis is provided on both sides near the center of the axial length of the lower half of the bearing shell; Since a bearing pedestal is provided to support this support seat, and the bearing load is supported by the cylindrical support seat with a short rotation radius, the moment of frictional resistance acting on the bearing pedestal during operation is significantly reduced. Therefore, this cylindrical support seat allows the support seat to follow up and down eccentricity in the axial direction for automatic alignment.

【Example】

The present invention will be described in detail below based on the drawings. FIG. 1 is a perspective view showing a part of a self-aligning journal bearing according to an embodiment of claim 1 of the present invention, and FIG. 2 is an explanatory diagram showing the frictional resistance moment of the self-aligning journal bearing of FIG. 1. It is. In FIG. 1, the self-aligning journal bearing according to the embodiment of the present invention is horizontally attached to both sides near the center of the axial length of the bearing shell 2, which is divided into two halves and consists of an upper half 2a and a lower half 2b. A support seat 5 extending in a direction perpendicular to the shaft 1 and having a cylindrical cross section and a bearing stand 6 for supporting the support seat 5 are provided. When machining the support seat 5, the bearing shell 2 is integrated and the support seat is machined into a cylindrical shape, and then the upper and lower bearing shells are
Split into two. In Figure 2, the load during installation is Po, the load during operation is P I + the weight of the bearing shell is wt, the weight of the shaft is W, the moment of frictional resistance during installation that acts on the bearing pedestal is Mo, and the moment of frictional resistance on the bearing pedestal is Mo. The frictional resistance moment during operation that is applied is M2. If the radius of rotation acting on the bearing stand is R1, then P(+ "vW+ Me = w, XR. PI = W, +w M+ = (wt +w)XR
. Therefore, since R1 is much shorter than Ro in Figure 6,
The frictional resistance moment acting on the bearing pedestal 6 during operation of the self-aligning journal bearing in FIG. 2 is greater than the frictional resistance moment acting on the bearing pedestal 4 during operation of the self-aligning journal bearing in FIG. significantly reduced. F is a frictional force acting on the contact surface between the support seat 5 and the bearing stand 6. FIG. 3 is a perspective view of a self-aligning journal bearing according to an embodiment of claim 2 of the present invention, and FIG. 4 is an explanatory diagram showing the N friction resistance moment of the self-aligning journal bearing of FIG. 3. In the embodiment shown in FIG. 3, a support seat 5 having a semi-cylindrical cross section and a support seat 5 extending in a direction perpendicular to the shaft 1 on both sides near the center of the axial length of the lower half 2b of the bearing shell 2; A bearing stand 6 for supporting the seat 5 is provided. When processing the support seat 5, the bearing shell 2 is integrated, the support seat 5 is processed into a cylindrical shape, the bearing shell is divided into upper and lower halves, and the support seat of the upper half of the shell is cut off. In Figure 4, the load during installation is Po, and the load during operation is P.
I + The weight of the bearing shell is wt, the weight of the shaft is W, and the frictional resistance moment acting on the bearing stand during installation is M6. The frictional resistance moment acting on the bearing stand during operation is M9. If the radius of rotation acting on the bearing stand is R, then P o ”i WZ MO= Wz X R
+P, =w2+w MI= (w, +W)XR. Therefore, since R1 is much shorter than R8 in Fig. 6,
The frictional resistance moment acting on the bearing pedestal 6 during operation of the self-aligning journal bearing in FIG. 4 is greater than the frictional resistance moment acting on the bearing pedestal 4 during operation of the self-aligning journal bearing in FIG. 6. significantly reduced.

【Effect of the invention】

According to claim 1, the present invention includes a support seat that extends in a direction perpendicular to the axis on both sides near the center of the axial length of the bearing shell and has a cylindrical cross section, and a bearing stand that supports the support seat. The bearing load is supported by a cylindrical support seat with a short rotation radius, and the frictional resistance moment acting on the bearing stand during operation is significantly reduced compared to conventional self-aligning journal bearings. Therefore, according to the self-aligning journal bearing of the present invention, the self-aligning function can be fully exhibited under a bearing load. According to a second aspect of the present invention, there is provided a support seat that extends in a direction perpendicular to the axis on both sides near the center of the axial length of the lower half of the bearing shell and has a semi-cylindrical cross section; The bearing load is supported by a cylindrical support seat with a short rotation radius, and the frictional resistance moment that acts on the bearing pedestal during operation is significantly reduced compared to conventional self-aligning journal bearings. reduce Therefore, according to the self-aligning journal bearing of the present invention, the self-aligning function can be fully exhibited under a bearing load.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a part of a self-aligning journal bearing according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the frictional resistance moment of the self-aligning journal bearing of FIG. 1, and FIG. 3 is a perspective view showing a part of a self-aligning journal bearing according to another embodiment of the present invention; FIG. 4 is an explanatory diagram showing the frictional resistance moment of the self-aligning journal bearing of FIG. 3;
FIG. 5 is a perspective view showing a part of a conventional self-aligning journal bearing, and FIG. 6 is an explanatory diagram showing the frictional resistance moment of the self-aligning journal bearing of FIG. 1: shaft, 2: bearing shell, 2a: upper half, 2b: lower half, 3, 5: support seat, 4, 6: bearing stand.

Claims (1)

[Scope of Claims] 1) A bearing shell with a top and bottom split structure that contacts the shaft and has a curved support seat on the outer diameter side near the center of the axial length, and a bearing stand that supports the support seat. A self-aligning journal bearing comprising: a support seat having a cylindrical cross section that extends from both sides near the center of the axial length of the bearing shell in a direction perpendicular to the axis; and a support seat that supports the support seat. A self-aligning journal bearing characterized by being provided with a bearing stand. 2) A self-aligning bearing shell with a top and bottom split structure that contacts the shaft and has a curved support seat on the outer diameter side near the center of the axial length, and a bearing stand that supports the support seat. type journal bearing, a support seat with a semi-cylindrical cross section that extends in a direction perpendicular to the axis on both sides near the center of the axial length of the lower half of the bearing shell, and a bearing that supports the support seat. A self-aligning journal bearing characterized by having a stand.