JPH066205Y2 - Bearing structure for heat exchanger drive shaft of gas turbine engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a bearing structure of a drive shaft for rotationally driving a heat storage body of a rotary heat storage heat exchanger in a gas turbine engine.

[Conventional technology]

As a prior art related to the present invention, Japanese Utility Model Publication No. 56-84156 is known. In the heat storage body drive gear device of the rotary heat storage heat exchanger disclosed in the present publication, a small gear storage portion for rotating the heat storage body is configured as an independent housing, and a function of adjusting the heat storage body drive portion by the small gears. While maintaining the above, the sealing property of high pressure air and the assembling property are improved.

FIG. 2 shows a bearing structure that supports a drive shaft for rotating a heat storage body in a conventional gas turbine engine. In the figure, the heat storage body 1 of the heat exchanger is supported by a support 3 attached to a casing 2, and a gear 4 is provided on the outer circumference of the heat storage body 1. A drive shaft 5 for rotating the heat storage body 1 is arranged in the hollow portion of the casing 2, and the drive shaft 5 is rotatably supported by two bearings 6 housed in the casing 2.

One of the drive shafts 5 is provided with a gear 7 that meshes with a gear 4 provided on the outer peripheral surface of the heat storage body 1, and the other is provided with a bevel gear 8. The bevel gear 8 is meshed with a bevel gear 10 attached to the input shaft 9, and the input shaft 9 is connected to a rotary drive source (not shown). A dust seal 10 is provided in the vicinity of the bearing 6 that supports the drive shaft 5 so that dust and the like mixed in during high-pressure ventilation do not enter the bearing 6. A grease 11 for lubricating the bearing 6 is filled between the two bearings 6 and between the bearing 6 on the gear 7 side and the dust seal 10.

[Problems to be solved by the invention]

However, in the bearing structure shown in FIG. 2, since the bearing 6 is in a high temperature atmosphere, the grease 11 that lubricates the bearing 6 is thermally deteriorated, and the lubrication effect of the bearing 6 becomes insufficient. Moreover, the filled grease 6 is blown off by the high-pressure air flowing in from the flow passage 12 in the engine, so a sufficient lubricating effect cannot be expected.

Therefore, it is conceivable to use a ceramic bearing in which the rolling element having better lubricity in a high temperature atmosphere than a general metal bearing is made of ceramic. However, even though it is a ceramic bearing having good lubricity, it cannot be completely lubricated in a high temperature atmosphere, and therefore lubrication with a powdered solid lubricant such as molybdenum disulfide is necessary. However, even with this structure, there is a problem that the encapsulated solid lubricant is blown off by the high pressure air in a short time as in the above, and a sufficient lubricating effect cannot be expected.

The present invention can eliminate the thermal deterioration of the lubricant due to the high temperature atmosphere, and can sufficiently lubricate the bearing that supports the drive shaft for rotationally driving the heat storage body for a long period of time, thereby significantly improving the durability of the bearing. An object of the present invention is to provide a bearing structure for a heat exchanger drive shaft of a gas turbine engine that can be improved.

[Means for solving problems]

A bearing structure for a heat exchange drive shaft of a gas turbine engine according to the present invention, which meets this purpose, has a drive shaft supported by a bearing, and a gear attached to the drive shaft is provided on an outer circumference of a heat storage body of a rotary heat storage heat exchanger. In a gas turbine engine in which the heat storage body is rotated by the rotation of the drive shaft by meshing with a gear formed by the drive shaft, a bearing for supporting the drive shaft is formed by a ceramic bearing whose rolling element is made of ceramic. At a position adjacent to the bearing, solid carbon which is slidably contactable with the drive shaft and one of which faces the ceramic bearing and the other of which faces a flow path through which high-temperature, high-pressure air flows is arranged.

[Action]

In the bearing structure for the heat exchange drive shaft of the gas turbine engine configured as described above, since the bearing that supports the drive shaft is composed of the ceramic bearing, the rolling element is in a higher temperature atmosphere than the conventional bearing made of metal. Lubricity is improved. Moreover, solid carbon, which is in sliding contact with the drive shaft side and is not thermally deteriorated by the high temperature atmosphere, is arranged at a position adjacent to the ceramic bearing, so that carbon abrasion powder generated by sliding contact between the drive shaft and carbon is high in temperature. , Adhered to the ceramic bearing by the flow of high pressure air. The abrasion powder of carbon acts as a solid lubricant, and the solid carbon serves as a supply source of the solid lubricant, so that this lubricating action is maintained for a long period of time.

Further, since the ceramic bearing faces the flow path of the high temperature / high pressure air through the solid carbon, the ceramic bearing does not come into direct contact with the high temperature / high pressure air. Therefore, dust mixed in the high temperature / high pressure air is prevented from entering the ceramic bearing.

〔Example〕

Hereinafter, a preferred embodiment of a bearing structure for a heat exchanger drive shaft of a gas turbine engine according to the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 21 in the drawing denotes a heat storage body of the rotary heat storage type heat exchanger of the gas turbine engine 20. A gear 22 extending in the circumferential direction is provided on the outer peripheral surface of the heat storage body 21, and the tooth width of the gear 22 is half the width of the heat storage body 21 or less. The outer peripheral surface of the heat storage body 21 is rotatably supported by a support 24 adjacent to the gear 22 and held by a casing 23. The casing 23 is provided with the support 24 on one side and is fitted on the housing 25 of the gas turbine engine 20 on the other side. The casing 23 is formed of a substantially tubular member, and is fixed to the housing 25 by a bolt 26 inserted in a flange portion 23a that bulges outward in the radial direction.

A drive shaft 27 extending in parallel with the rotation center axis of the heat storage body 21 is disposed in the hollow portion of the casing 23. Drive shaft 27,
It is rotatably supported by two ceramic bearings 28 arranged in the casing 23. In the ceramic bearing 28, balls 29 as rolling elements are made of ceramics, and an outer ring 30, an inner ring 31, and a retainer (not shown) for holding the balls 29 are made of metal similarly to a normal bearing. One outer ring 30 of the two ceramic bearings 28 is in contact with the stepped portion 23b in the casing 23, and the outer ring 30 of the other ceramic bearing 28 is attached to a retaining ring 33 mounted on the other end of the casing 23. Abutted. A spacer 34 is provided between the outer ring 30 of one of the two ceramic bearings 28 and the outer ring 30 of the other bearing to maintain the two ceramic bearings 28 at a predetermined distance. Similarly, the inner ring 31 of one of the two ceramic bearings 28
A spacer 35 is provided between the inner ring 31 and the inner ring 31 of the other bearing.

A gear 36 that meshes with the gear 22 provided on the outer peripheral surface of the heat storage body 21 is provided on one side of the drive shaft 27.
It is fixed by a nut 37 screwed into a threaded portion at one end of 27. A spacer 38 is interposed between the gear 36 and the inner ring 31 of the ceramic bearing 28 adjacent to the gear 36 so as to maintain a constant gap therebetween.

A bevel gear 39 is provided on the other side of the drive shaft 27,
The bevel gear 39 is fixed by a nut 40 screwed to the threaded portion at the other end of the drive shaft 27. Bevel gear 39
It meshes with a bevel gear 42 attached to an input shaft 41 extending in a direction orthogonal to the axis of the drive shaft 27. Bevel gear
42 is fixed by a nut 43 screwed to the input shaft 41, and the input shaft 41 is a bearing 4 provided in a casing 44.
It is rotatably supported by 5, 46. Casing 44
Are fixed to the engine housing 25 by bolts 47. A rotary drive source (not shown) is connected to the input shaft 41, and by rotating the input shaft 41, the heat storage body
The gear 36 of the drive shaft 27 that meshes with the gear 22 on the 21 side is rotated, and the heat storage body 21 is rotationally driven at a predetermined speed.

Solid carbon 48 is provided between the two ceramic bearings 28. That is, carbon 48
Is formed into a cylindrical shape as a carbon bearing, the outer peripheral surface of which is fitted into the spacer 34 and the inner peripheral surface of which is in contact with the spacer 35. Similarly, on the ceramic bearing 28 side adjacent to the gear 36, the inner peripheral surface contacts the spacer 38 and the outer peripheral surface is the casing.
Solid carbon 49 fitted to 23 is provided.
The carbon 49 has one end in contact with the outer ring 30 of the ceramic bearing 28 and the other end in contact with a retaining ring 50 mounted on one end of the casing 23.

One of the solid carbons 49 faces the flow path 51 through which the high temperature, high pressure air flowing out from the compression outlet flows. As a result, one of the ceramic bearings 28 faces the flow path 51 through which the high-temperature, high-pressure air flows via the solid carbon 49, and the ceramic bearing 28 is prevented from directly contacting the high-temperature, high-pressure air. There is.

Next, the operation of the bearing structure for the heat exchanger drive shaft of the gas turbine engine will be described.

First, when the input shaft 41 is rotationally driven by a rotary drive source (not shown), the bevel gear 39 meshing with the bevel gear 42 on the input shaft 41 side is rotated, and the drive shaft 27 is rotated. As the drive shaft 27 rotates, the gear 22 on the heat storage body 21 side that meshes with the gear 36 on the drive shaft 27 side is driven, and the heat storage body 21 rotates in a certain direction at a predetermined rotation speed. When the heat storage body 21 rotates, the flow path 51
The high-temperature, high-pressure air that passes through is exchanged with the heat stored in the heat storage body 21, and the temperature of the air is further increased.

In this case, when the drive shaft 27 rotates, the spacers 35 and 38 located on the outer periphery of the drive shaft 27 rotate together with the drive shaft 27, and the inner peripheral surface of the carbon 48 and the outer peripheral surface of the spacer 35, and the carbon
The inner peripheral surface of 49 and the outer peripheral surface of the spacer 38 are in sliding contact with each other. As a result, the inner surfaces of the carbons 48, 49 are abraded, and the carbon fines produced by the abrasion are attached to the respective ceramic bearings 28 by the pressure of the high temperature and high-pressure air passing through the flow path 51. In other words, due to the pressure in the flow path 51, the fine powder of carbon 49 that plays the role of the solid lubricant is supplied to the side of the ceramic bearing 28 that is used without lubrication. This fine carbon powder is carbon 4
It is supplied as much as 8 and 49 are worn, so that it is continuously supplied as long as the drive shaft 27 rotates, without worrying about being blown off by high pressure air in a short time unlike general solid lubricants. Therefore, the lubrication of the ceramic bearing 28 is sufficiently ensured, and its durability is significantly improved.

Further, since the carbons 48 and 49 are provided adjacent to the ceramic bearings 28, the high temperature and high pressure air passing through the flow path 51 does not come into direct contact with the ceramic bearings 28. That is, the solid carbons 48 and 49 have the effect of dust sealing, and prevent foreign matter from entering the ceramic bearing 28.

Furthermore, the solid carbons 48, 49 also function as a general slide bearing in the present embodiment, and partly bear the load of the ceramic bearing 28, so the load bearing of the ceramic bearing 28 is reduced, Ceramic bearing 28
The life of is extended.

In this embodiment, solid carbon is used as the slide bearing that supports the drive shaft, but it may be used as a dust seal that prevents foreign matter from entering as described above.

[Effect of device]

According to the bearing structure for the heat exchanger drive shaft of the gas turbine engine of the present invention, the bearing for supporting the drive shaft is composed of the ceramic bearing whose rolling element is made of ceramic, and the drive shaft side is provided adjacent to the ceramic bearing. The solid carbon is arranged so that it can be slidably contacted with one side and the other side is opposed to the ceramic bearing and the other side is opposed to the flow path through which high temperature and high pressure air flows. It becomes possible to supply the worn fine powder of carbon to the ceramic bearing for a long period of time, and it is possible to greatly improve the durability of the ceramic bearing in a high temperature atmosphere.

Further, since the ceramic bearing faces the flow path through which the high-temperature, high-pressure air flows via the solid carbon, the ceramic bearing does not come into direct contact with the high-temperature, high-pressure air. Therefore, it is possible to reliably prevent dust mixed in the high temperature / high pressure air from entering the ceramic bearing.

[Brief description of drawings]

1 is a sectional view of a bearing structure for a heat exchanger drive shaft of a gas turbine engine according to an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional bearing structure for a heat exchanger drive shaft of a gas turbine engine, Is. 20 …… Gas turbine engine 21 …… Heat storage element 22 …… Gear 27 …… Drive shaft 28 …… Ceramic bearing 29 …… Rolling element (ball) 36 …… Gear 48, 49 …… Solid carbon 51 …… High temperature・ High-pressure air flow path

Claims (1)

[Scope of utility model registration request] 1. A drive shaft is supported by a bearing, a gear attached to the drive shaft is meshed with a gear provided on the outer circumference of a heat storage body of a rotary heat storage heat exchanger, and the heat storage is performed by rotation of the drive shaft. In a gas turbine engine configured to rotate a body, a bearing that supports the drive shaft is formed of a ceramic bearing in which a rolling element is made of ceramic, and a position adjacent to the ceramic bearing can be slidably contacted with the drive shaft side. A bearing structure for a heat exchanger drive shaft of a gas turbine engine, in which solid carbon is arranged, one of which faces a ceramic bearing and the other of which faces a flow path through which high-temperature, high-pressure air flows.