JPH0451213Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is designed to reduce the heat generated from the shaft sealing device and bearings of a main engine such as a compressor that is rotated by a prime mover.
The present invention relates to a cooling mechanism that uses a flexible shaft joint that connects the shaft end of a prime mover shaft and the shaft end of a main engine shaft to cool the shaft end.

[Conventional technology]

Conventionally, the purpose is to prevent the shaft seals and bearings installed on the rotating shaft of the main engine such as the compressor from shortening their lifespan and damaging other peripheral equipment due to the heat generated from the shaft seals and bearings. in,
It is widely known to provide a cooling liquid supply (circulation) device or the like outside the device.

[The problem that the idea attempts to solve]

However, according to the above-mentioned conventional technology, power is required to drive the coolant supply (circulation) device, etc., and the device also becomes large in size.

In view of these problems, the present invention has developed a cooling mechanism that does not require any power for cooling by using a flexible shaft joint that transmits the output torque of the prime mover shaft to the main engine shaft as a cooling means. This is what we intend to provide.

[Means to solve the problem]

In order to achieve the above object, the cooling mechanism using the flexible shaft joint according to the present invention is provided between the shaft ends of the prime mover shafts facing each other in the axial direction and the shaft ends of the main engine shaft on which the shaft sealing device and the bearing are installed. are connected by a flexible shaft joint consisting of bellows at both ends and a tapered cylindrical body formed between the bellows and having a larger diameter on the main shaft side,
An appropriate amount of low boiling point coolant is sealed in a sealed space surrounded by the inner periphery of the shaft joint and both shaft ends, and the shaft end of the main engine shaft is formed into a cylindrical shape in contact with the refrigerant liquid. With this structure, the heat conducted to the shaft end of the main engine shaft is efficiently removed by absorbing and releasing latent heat accompanying the phase transformation of the low-boiling refrigerant liquid.

[Effect]

The flexible shaft joint transmits output torque from the prime mover shaft to the main machine shaft, and absorbs misalignment, vibration, etc. between the two shafts using bellows at both ends. In addition, when the heat generated in the shaft sealing device and bearing attached to the shaft end of the main engine shaft is conducted to the shaft end,
Since the shaft ends are cylindrical and have a large heat dissipation area, the refrigerant liquid in the closed space between the shaft ends absorbs a large amount of the heat as vaporization energy and evaporates, and the vapor is evaporated into the closed space. Due to the convection generated in the space, it moves toward the end of the motor shaft where it is at a low temperature, becomes saturated, and condenses while actively releasing the heat absorbed during evaporation as latent heat of condensation. That is, heat from the main engine side is efficiently radiated to the outside through a thermal cycle formed by phase transformation and convection of the low-boiling refrigerant. The low boiling point refrigerant that condenses into a liquid phase on the shaft end side of the prime mover shaft is compressed along the tapered cylindrical inner circumferential surface of the shaft joint due to the centrifugal force that accompanies the rotation of the shaft joint. It circulates toward the radial side, that is, the main engine side.

〔Example〕

Next, the present invention will be explained based on an embodiment shown in FIG.

In the figure, 1 is a prime mover shaft, and 2 is a main shaft of a compressor or the like that rotates in response to the output torque from the shaft 1. On the outer periphery of the shaft end of the main engine shaft 2 are a stationary ring 5 that is airtightly fitted to the main engine housing 3 and a rotating ring 6 that is airtightly supported on the main engine shaft 2 via a bellows 7. , 6, and a mechanical seal 4 as a shaft sealing device that seals zero bearing oil on the mutual sliding surfaces of the
A bearing 8 is mounted to rotatably support the.

Reference numeral 9 denotes a hollow flexible shaft joint that connects the shaft ends of the two shafts 1 and 2 facing each other in the axial direction, and includes bellows 10 and 11 at both ends;
It consists of a tapered cylindrical body 12 which has a larger diameter on the main shaft 2 side and is welded between 11 and 11. The main shaft 2
A cylindrical portion 13 is formed at the shaft end of the shaft, and is surrounded by the flexible shaft joint 9 and the shaft ends of both shafts 1 and 2, that is, the inner peripheral space of the shaft joint 9 and the inside of the cylindrical portion 13. A suitable amount of a refrigerant liquid 15, which is a low boiling point liquid such as ethyl alcohol, is sealed in a closed space 14 consisting of a surrounding space. 16 and 17 are the bellows 10, respectively.
A liquid absorbing member such as a sponge is fixed to the inner surface of 11, and 18 is a check valve provided at the refrigerant liquid inlet of the flexible shaft joint 9.

When both shafts 1 and 2 and the flexible shaft coupling 9 that connects them rotate, the refrigerant liquid 1 in the closed space 14
5 is the shaft joint 9 as shown in the figure due to centrifugal force.
The refrigerant 15 is unevenly distributed on the inner periphery of the bellows 11 on the large diameter side (main engine shaft 2 side) and is retained in the liquid absorbing member 17, and a part of the refrigerant 15 is stored in the cylindrical portion 1 of the main engine shaft 2.
3 Flows into the inner circumference. As the main engine shaft 2 rotates, heat generated on the sliding surfaces of both rings 5 and 6 of the mechanical seal 4 and the bearing 8 is conducted to the main engine shaft 2, but the shaft end of the shaft 2 is shaped like a cylinder as described above. Since the cylindrical portion 13 has a large heat radiation area, the refrigerant liquid 15 in contact with the cylindrical portion 13 absorbs a large amount of the heat as vaporization heat and evaporates actively. Then, as shown by arrow A in the figure, this refrigerant vapor flows toward the low-temperature motor shaft 1 side by convection in the closed space 14, where it condenses and becomes a liquid phase while releasing a large amount of latent heat. Return, bellows 1 on the motor shaft 1 side
The liquid is absorbed and accumulated by the liquid absorbing member 16 provided on the inner surface. The refrigerant liquid 15 overflowing from the liquid absorbing member 16 is caused by the centrifugal force caused by the rotation to cause the inner circumferential surface of the tapered cylinder 12 of the flexible shaft joint 9 to move as shown by arrow B in the figure. It flows toward the larger diameter side and is collected on the cylindrical portion 13 side of the main engine shaft 2.

Note that the refrigerant liquid 15 is not limited to ethyl alcohol, and can be appropriately selected depending on the operating temperature conditions, and the amount of the refrigerant to be filled depends on the volume inside the bellows 10, 11 where the liquid accumulates and It is determined by considering the inner diameter of the cylindrical portion 13 of the main shaft 2, etc.

[Effect of idea]

As explained above, the present invention seals an appropriate amount of refrigerant liquid in the sealed space formed by the prime mover shaft end, the main engine shaft end, and the hollow flexible shaft joint that connects the two shaft ends. By forming a thermal cycle due to phase transformation, it is possible to remove heat from the shaft sealing device and bearings installed on the main engine shaft without using an external cooling device. Since the shaft end is formed into a cylindrical shape to increase the heat dissipation area, an excellent cooling effect can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of essential parts showing an embodiment of the cooling mechanism of the present invention. 1... Prime mover shaft, 2... Main machine shaft, 3... Main machine housing, 4... Mechanical seal, 8... Bearing, 9... Flexible shaft coupling, 10, 11... Bellows, 12... Tapered shape Cylindrical body, 13...Cylindrical part, 1
4... Closed space, 15... Refrigerant liquid.

Claims (1)

[Scope of utility model registration request] The shaft end of the prime mover shaft that extends in the axial direction and the shaft end of the main engine shaft on which the shaft sealing device and the bearing are attached are connected by bellows at both ends and the main engine shaft side formed between the two bellows has a large diameter. The main engine A cooling mechanism using a flexible shaft joint, characterized in that the shaft end of the shaft is formed into a cylindrical shape that contacts the refrigerant liquid.