JP2000266058A - Ceramic bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To support a rotating shaft stably by preventing a ceramic bearing member from being broken caused by reduction or loss in/of a cushioning function and preventing sliding properties from becoming worse caused by making the ceramic bearing member catch the rotating shaft or a shaft sleeve the ceramic even if the frequency of dry operation under a non-lubricant condition become high or dry operation time is continued for a long time. SOLUTION: A cushion 2 is disposed between a metallic shell 3 engaging and retaining a ceramic annular bearing member 1 and the outmost peripheral metallic shell 3. The cushion 2 is provided with a metallic sleeve 6 which is elastically deformable in a radial direction, four metallic supports 71-74 weldedly-fixed onto the inner peripheral of the sleeve 6 at even intervals circumferentially, and four metallic supports 75-78 weldedly-fixed onto the outer periphery of the sleeve 6 at even intervals circumferentially being displaced circumferentially to the four metallic supports 71-74.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic bearing particularly suitable for supporting a main shaft of a vertical shaft pump or a horizontal shaft mixed flow pump.

[0002]

2. Description of the Related Art In a radial bearing used for a shaft support of a main shaft such as a vertical shaft pump and a horizontal shaft mixed flow pump, lubrication and cooling are performed by self-pumping water during normal pumping operation, and lubrication and cooling by self-pumping water are cut off. As a bearing that allows dry operation for a short time during initial operation, etc., as shown in FIG.
As shown in FIG. 6, the ceramic bearing members 1, 1... Divided into segments are made of stainless steel or the like via a cushioning member 2 made of an elastic body such as hard rubber at equal intervals in the circumferential direction. There is known a ceramic bearing in which a metal shell 3 is held by a metal shell 3 and the metal shell 3 is fitted into a metal housing 4 made of stainless steel or the like and integrally joined thereto.

When the main shaft 5 such as a vertical shaft pump or a horizontal mixed flow pump is supported by a ceramic bearing having such a structure, a part of the self-pumping water is fitted to the outer peripheral surface of the main shaft 5 or the main shaft 5 during the pumping operation. Shaft sleeve (not shown)
Lubrication and cooling of the outer peripheral surface of the ceramic bearing members 1, 1..., And the cooling of the ceramic bearing members 1, 1. Can be supported.
Also, even in a dry operation in a non-lubricated state in which the above-described lubrication and cooling by self-pumping can not be expected, the main shaft 5 is stabilized without burning or burning due to the heat resistance of the ceramic bearing members 1, 1... Can be supported.

Further, a radial load is applied to the ceramic bearing members 1, 1...
When the ceramic bearing members 1, 1, ... are displaced in the radial direction, the displacement is absorbed by the elastic deformation of the cushioning member 2, and the damping function is exhibited. Can be prevented.

[0005]

However, the frictional heat generated by the friction between the ceramic bearing members 1, 1,... And the shaft sleeve or the main shaft 5 causes the ceramic bearing members 1, 1,.
When the temperature of the... Rises, the buffer member 2 made of an elastic body such as hard rubber having a low thermal conductivity accumulates heat and rises in temperature. For this reason, thermal degradation occurs and the buffer function is reduced or lost, and the ceramic bearing members 1, 1,... Are damaged, and the thermal expansion of the buffer member 2 urges the ceramic bearing members 1, 1,. As a result, the slidability is deteriorated by being held by the main shaft 5 or the shaft sleeve,
There is a possibility that the stable support of the above is hindered. Therefore, the spindle 5 is stably supported under the use condition in which the dry operation for a short time is repeatedly performed or the use condition in which the aerial operation (dry operation) in a non-lubricated state is continued for a long time, such as a preceding standby operation pump. I can't expect to do that.

Therefore, the present invention can prevent the ceramic bearing member from being damaged due to a reduction or loss of the buffer function even under a use condition in which the dry operation is frequently performed for a short time or under a use condition in which the dry operation is continued for a long time. As well as
An object of the present invention is to provide a ceramic bearing that can stably support a rotating shaft by avoiding that a ceramic bearing member is urged inward in a radial direction and is hung on a rotating shaft or a shaft sleeve to deteriorate slidability. And

[0007]

In order to achieve the above object, a ceramic bearing according to the present invention slides on the outer periphery of a rotating shaft 5 or an outer periphery of a shaft sleeve attached to the rotating shaft 5 so as to be able to rotate simultaneously. An annular bearing member 1 made of ceramics which comes into contact, a metal shell 3 which fits and holds the annular bearing member 1 made of ceramics, and a cushioning member 2 arranged on the outer periphery of the metal shell 3; A metal housing 4 arranged on the outer periphery of the buffer member 2,
The cushioning member 2 has at least one metallic sleeve 6 elastically deformable in the radial direction provided between the shell 3 and the housing 4, and has a circumferential space on both inner and outer circumferences of the sleeve 6. In addition, a plurality of inner and outer peripheral sides are provided so as to be inconsistent with each other in the circumferential direction, and a displacement of the ceramic bearing member 1 and the metal shell 3 in the radial direction due to the shaft runout of the rotary shaft 5 is prevented. And a plurality of metal supports 71, 72,... Which are displaced following and urge the sleeve 6 in the radial direction to be elastically deformed.

According to the present invention, when a radial load acts on the ceramic annular bearing member due to the inclination or bending of the rotating shaft and the annular bearing member and the shell are displaced in one radial direction, the displacement follows the displacement. At least one metal support provided on the inner peripheral side of the metal sleeve is displaced in the anti-axial direction on the displacement side in the anti-axial direction in the one direction, and the sleeve is displaced in the outer peripheral side of the sleeve. The two metal supports provided in the same direction are urged in the anti-axial direction to elastically deform, and are provided on the inner peripheral side of the metal sleeve on the axially displaced side in the one direction. At least one metal support is axially displaced, and the sleeve is elastically deformed by axially urging the sleeve between two metal supports provided on the outer peripheral side of the sleeve. By absorbs displacement in the radial direction of the ceramic annular bearing member and the shell, by exhibiting a pH buffer function, it is possible to prevent damage to the ceramic annular bearing member. In addition, even if the frequency of the short-time dry operation is increased or the dry operation is continued for a long time, even if the temperature of the annular bearing member made of ceramics becomes high, the cushioning member is made of an elastic body such as a conventional hard rubber. Compared to the cushioning member, it is composed of a metal sleeve having a high heat conductivity and excellent heat resistance and a plurality of metal supports provided on both the inner and outer circumferences of the metal sleeve. The buffer function is not reduced or lost due to the deterioration. Further, since the ceramic bearing member is formed in an annular shape, it is not hugged by the main shaft or the shaft sleeve.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. 1 is a longitudinal sectional side view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, and the same or corresponding parts as those in the conventional example in FIGS. The description will be made with reference to FIG. 1 and 2
, The ceramic bearing is fitted around the main shaft 5 of the vertical pump so as to be rotatable at the same time.
A, a ceramic annular bearing member 1 that comes into sliding contact with the outer periphery of A, a metal shell 3 that fits and holds the ceramic annular bearing member 1, and a metal shell 3
And a metal housing 4 disposed on the outer periphery of the buffer member 2 and fixed to a pumping pipe (not shown) of a vertical shaft pump via a bearing base 8. Thus, the main shaft 5 is rotatably supported. The shaft sleeve 5A is made of a cemented carbide such as tungsten carbide.

The cushioning member 2 is a metal sleeve 6 elastically deformable in the radial direction provided between the shell 3 and the housing 4 and is welded to the inner periphery of the sleeve 6 at equal circumferential intervals. And four metal supports 71, 72, 73, and 74 fixed at the same time on the outer circumference of the sleeve 6 at equal intervals in the circumferential direction.
Four metal supports 75, 76, 77, 78 fixed by welding in a circumferential direction with respect to the metal supports 3, 74, and the inner surfaces of the metal supports 71, 72, 73, 74 are made of metal. The outer surface of each of the metal supports 75, 76, 77, 78 is in contact with the inner circumference of the metal housing 4. The shell 3, the housing 4, the sleeve 6, and the supports 71 to 7
8 is made of stainless steel, and the metal sleeve 6 is made of a thin spring steel plate. In FIG. 1, reference numeral 9 denotes a key, and a shaft sleeve 5A is connected to the main shaft 5 so as to be simultaneously rotatable.

If the main shaft 5 such as a vertical shaft pump or a horizontal shaft mixed flow pump is supported by the ceramic bearing configured as described above, at the time of pumping operation, a part of the self pumping water is externally fitted to the main shaft 5 to simultaneously pump the pump. It lubricates and cools the outer peripheral surface of the rotatable shaft sleeve 5A and the sliding surface of the ceramic annular bearing member 1, and also cools the entire ceramic bearing to stably support the main shaft 5.

On the other hand, even during a dry operation such as an initial operation in which lubrication and cooling of the sliding surface by the self-pumping water and cooling of the entire ceramic bearing cannot be expected, due to the excellent heat resistance of the annular bearing member 1 made of ceramics, seizure and burning are caused. And the main shaft 5 can be stably supported.

A radial load acts on the annular bearing member 1 made of ceramics due to the inclination or bending of the main shaft 5, and the annular bearing member 1 and the shell 3 are tentatively moved to the axis O of the main shaft 5 in FIG.
Is displaced in a radial direction indicated by an arrow X passing through the metal support 6 on the inner peripheral side of the metal sleeve 6 on the displacement side in the direction of the anti-axial center O in the direction of the arrow X following this displacement. 3 is displaced in the direction of the anti-axial center O from the solid line position in FIG. 3 to the position of the two-dot chain line, and the sleeve 6 is moved in the anti-axial direction between the two metal supports 75 and 78 provided on the outer peripheral side thereof. The metallic support 73 provided on the inner peripheral side of the metallic sleeve 6 is biased to be elastically deformed as shown by a two-dot chain line, and a metallic support 73 provided on the inner peripheral side of the metallic sleeve 6 on the displacement side in the direction of the axis O in the direction of the arrow X. Displaced in the O direction, the sleeve 6
The two metal supports 7 provided on the outer peripheral side
By urging in the direction of the axis O between 6, 77 and elastically deforming as shown by the two-dot chain line, the displacement of the annular bearing member 1 and the shell 3 made of ceramics in the direction of arrow X is absorbed, By exhibiting the cushioning function, breakage of the ceramic annular bearing member 1 can be prevented, and the main shaft 5 can be stably supported. Such a buffering function is not limited to the radial displacement indicated by the arrow X passing through the axis O of the main shaft 5 in FIG. It also exerts a damping function by absorbing all radial displacements passing through the axis O of the main shaft 5 to prevent the annular bearing member 1 made of ceramics from being damaged. 5 can be stably supported.

Further, the frequency of the short-time dry operation increases, or the dry operation is continued for a long time.
Are provided on both the inner and outer peripheral sides of the metal sleeve 6 having high thermal conductivity and excellent heat resistance as compared with the buffer member 2 made of an elastic body such as a conventional hard rubber. Therefore, the buffer function is not reduced or lost due to thermal deterioration. For this reason, the ceramic annular bearing member 1 can be used under a condition in which a dry operation in a short time is repeatedly performed or a condition in which a dry operation in a non-lubricated state is continued for a long time, such as a preceding standby operation pump.
Can be stably supported without damaging the main shaft 5. Furthermore, since the ceramic bearing member 1 is formed in an annular shape, it does not cling to the shaft sleeve 6A. As a result, the slidability is prevented from deteriorating, and
Can be stably supported.

Further, one elastically deformable metal sleeve 6 having the cushioning member 2 interposed between the shell 3 and the housing 4 is provided on both inner and outer peripheral sides of the metal sleeve 6 with circumferential intervals. And eight metal supports 71 to 78 provided on both sides of the inner and outer circumferences so as to be inconsistent in the circumferential direction. As shown in FIG.
Two elastically deformable metal sleeves 6 and 6 interposed between the metal sleeves 6, and the metal sleeve 6 has a circumferential interval on both the inner and outer circumferences, and the inner and outer circumferences are circular. The shock-absorbing member 2 may be constituted by twelve metal supports 71 to 82 which are provided in a circumferentially misaligned manner. In addition, there are circumferential intervals on both the inner and outer circumferences of the elastically deformable metal sleeve 6, and the inner and outer circumferences are misaligned in the circumferential direction, so that four inner and outer circumferences are respectively provided. Although metal supports are provided, four or more (for example, 6
To 8) metal supports may be provided. Further, the fixing is not limited to the fixing by welding, but may be fixing by an adhesive or fixing by fastening using a bolt or a rivet.

Further, a configuration is described in which the ceramic annular bearing member 1 is brought into sliding contact with the outer periphery of a shaft sleeve 5A which is fitted around the main shaft 5 so as to be rotatable at the same time. May be omitted and the ceramic annular bearing member 1 may be brought into sliding contact with the outer periphery of the main shaft 5.

[0017]

As described above, according to the present invention, even if the frequency of the short-time dry operation is increased or the dry operation is continued for a long time, even if the temperature of the ceramic annular bearing member becomes high, the cushioning effect is obtained. The member is made of a metal sleeve having high heat conductivity and excellent heat resistance as compared with a conventional buffer member made of an elastic body such as hard rubber, and a plurality of metal sleeves provided on both inner and outer circumferences of the metal sleeve. Since it is constituted by individual metal supports, the buffer function is not reduced or lost due to thermal deterioration. For this reason, the ceramic annular bearing member may be damaged even under the operating conditions in which the dry operation for a short time is repeatedly performed, or the operating condition in which the dry operation in an unlubricated state is continued for a long time, such as in the case of a preceding standby operation pump. Without rotating, the rotating shaft can be stably supported. Further, since the ceramic bearing member is formed in an annular shape, the bearing member is not hugged by the rotating shaft or a shaft sleeve externally fitted to the rotating shaft. This allows
The rotation shaft can be stably supported while the slidability is not deteriorated.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is an explanatory view showing a partially enlarged example of a buffer operation of a buffer member.

FIG. 4 is a diagram corresponding to FIG. 2, showing another embodiment of the cushioning member.

FIG. 5 is a longitudinal sectional side view of a conventional example.

FIG. 6 is a sectional view taken along line BB of FIG. 5;

[Explanation of symbols]

 Reference Signs List 1 annular bearing member made of ceramics 2 cushioning member 3 metal shell 4 metal housing 5 main shaft (rotating shaft) 5A shaft sleeve 6 metal sleeve elastically deformable in radial direction 7 metal support 71-78 metal support

Claims (1)

[Claims] An annular bearing member made of ceramics, which comes into sliding contact with the outer periphery of a rotating shaft or the outer periphery of a shaft sleeve attached to the rotating shaft so as to be rotatable at the same time, is fitted with the annular bearing member made of ceramics. A metal shell to be held; a cushioning member arranged on the outer periphery of the metal shell; and a metal housing arranged on the outer periphery of the cushioning member, wherein the cushioning member is disposed between the shell and the housing. At least one metal sleeve that is elastically deformable in the radial direction and has a circumferential interval on both the inner and outer circumferences of the sleeve, and both inner and outer circumferences have circumferentially misaligned plural pieces. And the sleeve is displaced following the radial displacement of the ceramic bearing member and the metal shell accompanying the shaft runout of the rotating shaft, and the sleeve is displaced in the radial direction. And a plurality of metal supports that are elastically deformed by being urged against the ceramic bearing.