JP2806573B2 - Ceramic bearing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a ceramic bearing device, and more particularly to a ceramic bearing device suitable for dry operation without lubrication.

[Prior Art] Conventional ceramic bearing devices are disclosed in, for example,
As described in Japanese Unexamined Patent Publication No. 822, in the sliding state, it is assumed that water is interposed between the cemented carbide sleeve and the ceramic piece (ceramic bearing). The frictional heat generated between the sleeve and the ceramic piece could cause the carbide sleeve to crack. Therefore, it cannot be applied to bearings that are used without lubrication during operation, such as bearings for pumps that are operated on standby in preparation for recent urban floods.

[Problems to be Solved by the Invention] The above prior art does not consider the reliability of the ceramic bearing during dry operation, and has a problem that the ceramic bearing cannot be applied to a pump or the like that is operated for a long time in dry operation. Was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and has as its object to provide a highly reliable ceramic bearing device capable of performing a long-time dry operation.

[Means for Solving the Problems] In order to achieve the above object, a first aspect of the ceramic bearing device according to the present invention comprises at least a carbide sleeve to be fitted on the rotating shaft side and a cemented carbide sleeve. In a ceramic bearing device including a ceramic bearing fitted to a sleeve to form a sliding portion, and an elastic body supporting the ceramic bearing, means for detecting a temperature of a member near the sliding portion; A means for supplying a coolant for cooling and lubrication to the sliding portion in conjunction therewith is provided.

Further, the configuration of the second invention according to the ceramic bearing device of the present invention includes at least a carbide sleeve to be fitted on the rotating shaft side, a ceramic bearing fitted to the carbide sleeve to form a sliding portion, In a ceramic bearing device provided with an elastic body supporting the ceramic bearing, a rotary shaft is formed as a vertical hollow shaft in which a hollow portion is previously filled with cooling water, and a rotary shaft is bored near the sliding portion of the hollow shaft. 1
And a valve body provided in the first small hole portion so as to be openable and closable via an elastic member. When the shaft rotates, the valve body opens the first small hole to supply the cooling water in the hollow portion to the sliding portion.

Further, the configuration of the third invention according to the ceramic bearing device of the present invention includes at least a carbide sleeve to be fitted on the rotating shaft side, a ceramic bearing fitted to the carbide sleeve to form a sliding portion, A ceramic bearing device comprising an elastic body supporting the ceramic bearing, wherein a cooling and lubricating medium that melts due to a rise in temperature of the sliding portion is brought into contact with a member near the sliding portion via an elastic member. It is.

Still further, the fourth aspect according to the ceramic bearing device of the present invention.
The invention has at least a carbide sleeve to be fitted on the rotating shaft side, a ceramic bearing fitted to the carbide sleeve to form a sliding portion, and an elastic body supporting the ceramic bearing. In a ceramic bearing device, a shape memory alloy brought into contact with a member near the sliding portion, a valve body connected to the shape memory alloy, and a supply path for a cooling and lubricating medium that opens and closes by the movement of the valve body. It is provided.

[Operation] The concept of developing the present invention and the basic functions of the above technical means are as follows.

In the ceramic bearing during the dry operation, the temperature of the cemented carbide sleeve rises due to frictional heat generated by sliding the cemented carbide sleeve and the ceramic without lubrication. Since the linear expansion coefficient of the carbide sleeve is smaller than that of general shaft materials,
A problem arises in that thermal stress is generated in the cemented carbide sleeve and cracks occur in the cemented carbide sleeve.

Cooling, sliding on the sliding surface between the carbide sleeve and the ceramic bearing
When a medium for lubrication is supplied, the medium exchanges heat with the cemented carbide sleeve to suppress the temperature of the cemented carbide sleeve, reduce the coefficient of friction of the sliding portion, and suppress the generation of heat. Thereby, the bearing temperature can be maintained at a temperature equal to or lower than the temperature at which the crack occurs, and furthermore, even if the bearing is rapidly cooled by pumping after the dry operation, the occurrence of the crack due to the thermal shock can be suppressed.

Embodiments Embodiments of the present invention will be described below with reference to FIGS. 1 to 8.

First, an embodiment of the first invention will be described with reference to FIG.

FIG. 1 is a configuration diagram of a ceramic bearing device according to one embodiment of the present invention, and FIG. 2 is a sectional view of a general ceramic bearing device.

In FIG. 2, reference numeral 1 denotes a rotating shaft of a pump or the like;
Is a ceramic sleeve fitted to the rotating shaft 1, 3 is a ceramic bearing which is fitted to the carbide sleeve 2 to form a sliding portion (sliding surface), and 4 is an elastic material such as hard rubber. The formed elastic body, 5 is a back metal, and 10 is a bearing housing.

As described above, the general ceramic bearing device has a structure in which the ceramic bearing 3 is supported by the bearing housing 10 via the back metal 5 and the elastic body 4 and can follow the inclination of the rotating shaft 1.

FIG. 1 shows an embodiment of a ceramic bearing device employing the most basic first invention of the present invention. In the figure, the second
The same reference numerals as those in the drawings denote the same parts as those of the conventional general ceramic bearing device.

In FIG. 1, reference numeral 6 denotes a temperature sensor relating to a means for detecting a temperature of a member near the sliding portion, 7 denotes a valve control device, 8
Is a medium for cooling and lubricating the sliding portion (hereinafter simply referred to as cooling and lubricating medium), for example, using cooling water or lubricating oil. Reference numeral 9 denotes a supply valve provided in a flow path for supplying the cooling and lubricating medium 8 to the sliding portion. These constitute a means for supplying a medium for cooling and lubrication to the sliding portion in conjunction with the detected temperature.

During a dry operation of a pump or the like employing a ceramic bearing device, the temperature of the carbide sleeve 2 rises due to frictional heat generated on the sliding surface between the carbide sleeve 2 and the ceramic bearing 3. This temperature rise is sensed by the temperature sensor 6 and its output is input to the valve control device 7, and when a certain temperature is reached,
The supply valve 9 is opened to supply the cooling and lubricating medium 8 to the sliding portions of the carbide sleeve 2 and the ceramic bearing 3. By doing so, the heating of the carbide sleeve 2 can be prevented, and the occurrence of heat cracks can be prevented.

If the valve control device 7 is set so that the supply valve 9 is closed when the temperature further decreases, the temperature of the bearing can be kept at a certain temperature or less regardless of operating conditions, and the carbide sleeve due to thermal stress can be maintained. 2 can be prevented, and even when the operation is switched to the wet operation, the occurrence of cracks in the carbide sleeve 2 due to the thermal shock can be prevented.

Next, an embodiment of the second invention will be described with reference to FIG.

FIG. 3 is a sectional view of a ceramic bearing device according to another embodiment of the present invention. In the drawings, those having the same reference numerals as those in FIGS. 1 and 2 are the same as those in the previous embodiment or the general ceramic bearing device, and the description thereof will be omitted.

In the embodiment shown in FIG. 3, a hollow shaft is used as means for cooling and supplying a lubricating medium to a sliding portion.

In FIG. 3, 1A is a hollow shaft, 11 is a first small hole drilled in the vicinity of the fitting portion (near the sliding portion) of the carbide sleeve 2 of the hollow shaft 1A, and 12 is a first small hole 11 13 that opens and closes the
The spring according to the elastic member supporting the valve body 12, 14 is a hollow shaft 1A
The water 15 for cooling the sliding portion filled in the hollow portion is a second small hole perforated above the first small hole 11, and the cover 20 prevents the water 14 from being lost.

In the apparatus of the embodiment shown in FIG. 3, the hollow portion inside the hollow shaft 1A is filled with water 14 before starting. After the start, when the hollow shaft 1A starts to rotate, centrifugal force acts on the valve body 12, the tension of the spring 13 overcomes, and a gap is formed between the first small hole 11 and the valve body 12,
Water 14 is supplied to the sliding portion between the carbide sleeve 2 and the ceramic bearing 3 from the gap, thereby suppressing an increase in bearing temperature. Further, heat exchange between the cemented carbide sleeve 2 and the water 14 through the hollow shaft 1A prevents the cemented carbide sleeve 2 from being heated.

Although not shown, the ceramic bearing device shown in FIG.
If the rotary shaft is attached to a vertical shaft pump having a hollow shaft, and the second small hole 15 is made to communicate with the inside of the pump, after pumping starts,
The water 14 in the hollow portion can be automatically supplied.

Similarly, although not shown, if the second small hole 15 is disposed near the pump shaft sealing portion, the water 14 can be automatically replenished by the initial water supply or the ground leaking liquid.

Although not particularly shown, as a resilient member for opening and closing the valve body 12, using a shape memory alloy or bimetal,
If it is mounted so as to be linked to the temperature of the members near the sliding portion such as the carbide sleeve 2 and the ceramic bearing 3, the same operation and effect as the embodiment of FIG. 3 can be expected.

Next, an embodiment of the third invention will be described with reference to FIG. 4 and FIG.

FIG. 4 is a sectional view of a ceramic bearing device according to still another embodiment of the present invention, and FIG. 5 is a view taken in the direction of arrow A in FIG.

In the figure, reference numeral 16 denotes a solvent relating to a cooling and lubricating medium which melts when the temperature of the sliding portion rises, reference numeral 17 denotes a spring relating to an elastic member for supporting the solvent 16 on the back metal 5, and
As shown in FIG. 5, a plurality (three in FIG. 5) of carbide sleeves 2 are in contact with each other.

In other words, in the embodiment shown in FIGS. 4 and 5, the spring 17 supports a solvent 16 that dissolves at a temperature lower than the temperature at which a heat crack occurs in the carbide sleeve 2 near the sliding portion of the carbide sleeve 2 and the ceramic bearing 3. It is a structure of contact.

When the temperature of the cemented carbide sleeve 2 is increased by a dry operation or the like, the solvent 16 in contact with the cemented carbide sleeve 2 is dissolved by the spring 17 due to the temperature increase of the cemented carbide sleeve 2.
Solvent 2 is made of carbide sleeve 2 and ceramic bearing 3
This cools and lubricates the sliding part, thereby suppressing the temperature rise of the sliding part.

In the present embodiment, a shape memory alloy or bimetal is used in place of the spring 17 and only when the temperature reaches a predetermined temperature in conjunction with the temperature rise of members near the sliding portion such as the carbide sleeve 2 and the ceramic bearing 3. With a structure in which the solvent 16 is brought into contact with the carbide sleeve 2, it is possible to prevent the solvent from being worn during normal operation.

Next, an embodiment of the fourth invention will be described with reference to FIG. 6 to FIG.

FIG. 6 is a sectional view of a ceramic bearing device according to still another embodiment of the present invention, and FIGS. 7 and 8 are detailed views of FIG. In the figure, components having the same reference numerals as those in FIG. 1 are the same as those in the previous embodiment, and the description thereof will be omitted.

In the figure, reference numeral 18 denotes a shape memory alloy that is brought into contact with a member near the sliding portion, and 19 denotes a valve body connected to the shape memory alloy 18. That is, one end of the shape memory alloy 18 is connected near the sliding portion between the ceramic bearing 3 and the carbide sleeve 2. A valve body 19 is connected to one end. Shape memory alloy for temperature rise of sliding part between carbide sleeve 2 and ceramic bearing 3
Detect by 18 The shape memory alloy 18 contracts when the temperature is normal temperature, and expands when the temperature rises.

At the start of the dry operation or the like, since the temperature of the sliding portion between the carbide sleeve 2 and the ceramic bearing 3 is low, the shape memory alloy 18 is in a contracted state as shown in FIG. It is closed. Therefore, the cooling and lubricating medium 8 is not supplied to the sliding portion. Dry operation for a long time,
When the temperature of the sliding portion between the carbide sleeve 2 and the ceramic bearing 3 rises due to frictional heat, as shown in FIG. 8, the shape memory alloy 18 expands and the valve element 19 is opened. Therefore, the cooling and lubricating medium 8 is supplied to the sliding portion, so that the temperature rise in the sliding portion can be suppressed, and the occurrence of heat cracks in the carbide sleeve 2 can be prevented. On the other hand, when the temperature of the sliding portion suddenly drops, for example, when the operation is changed from the dry operation to the wet operation, as shown in FIG.
Contracts, the valve element 19 closes, and the supply of the cooling and lubricating medium 8 is stopped.

According to each of the above embodiments, a ceramic bearing which could not be dry-operated conventionally can be dry-operated for a long time. High ceramic bearings can be applied.

[Effects of the Invention] As described above in detail, according to the present invention, it is possible to provide a highly reliable ceramic bearing device capable of performing dry operation for a long time.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a ceramic bearing device according to one embodiment of the present invention, FIG. 2 is a cross-sectional view of a general ceramic bearing device, and FIG. 3 is a ceramic bearing device according to another embodiment of the present invention. FIG. 4 is a sectional view of a bearing device, FIG. 4 is a sectional view of a ceramic bearing device according to still another embodiment of the present invention, and FIG.
FIG. 6 is a sectional view of a ceramic bearing device according to still another embodiment of the present invention, and FIGS. 7 and 8 are detailed views of FIG. 1 ... rotating shaft, 1A ... hollow shaft, 2 ... carbide sleeve, 3
... ceramic bearing, 4 ... elastic body, 6 ... temperature sensor, 7 ... valve control device, 8 ... cooling, lubricating medium, 9 ...
Supply valve, 11: first small hole, 12: valve body, 13: spring,
14 ... water, 15 ... second small hole, 16 ... solvent, 17 ... spring, 18 ... shape memory alloy, 19 ... valve body.

────────────────────────────────────────────────── ─── Continued on the front page (72) Akira Nemoto, Inventor 603, Kandamachi, Tsuchiura-shi, Ibaraki Pref. Hitachi, Ltd. Tsuchiura Plant (56) References JP-A-63-88319 (JP, A) (58) Investigated Field (Int.Cl. ⁶ , DB name) F16C 37/00 F16C 33/24

Claims (4)

(57) [Claims] A ceramic comprising at least a carbide sleeve to be fitted on the rotating shaft side, a ceramic bearing fitted to the carbide sleeve to form a sliding portion, and an elastic body supporting the ceramic bearing. In the bearing device, there is provided a means for detecting a temperature of a member near the sliding portion, and a means for supplying a coolant for cooling and lubrication to the sliding portion in conjunction with the detected temperature. Ceramic bearing device. 2. A ceramic comprising at least a carbide sleeve to be fitted on the rotating shaft side, a ceramic bearing fitted to the carbide sleeve to form a sliding portion, and an elastic body supporting the ceramic bearing. In the bearing device, a rotary shaft is a vertical hollow shaft in which a hollow portion is filled with cooling water in advance, a first small hole drilled near the sliding portion of the hollow shaft, It has a second small hole drilled in the upper part, and a valve body provided in the first small hole portion so as to be openable and closable via an elastic member, and when the hollow shaft rotates, the valve body is the first small hole. A ceramic bearing device, characterized in that the small hole is opened to supply cooling water in the hollow portion to the sliding portion. 3. A ceramic comprising at least a carbide sleeve to be fitted on the rotating shaft side, a ceramic bearing fitted to the carbide sleeve to form a sliding portion, and an elastic body supporting the ceramic bearing. A ceramic bearing device, wherein a cooling and lubricating medium that melts when the temperature of the sliding portion rises is brought into contact with a member near the sliding portion via an elastic body. 4. A ceramic comprising at least a carbide sleeve to be fitted on the rotating shaft side, a ceramic bearing fitted to the carbide sleeve to form a sliding portion, and an elastic body supporting the ceramic bearing. In a bearing device, a shape memory alloy contacted with a member near the sliding portion, a valve body connected to the shape memory alloy, and a supply path for a cooling and lubricating medium that opens and closes by the movement of the valve body are provided. A ceramic bearing device.