JPS62262632A - Rotary electric machine - Google Patents

Abstract

PURPOSE:To cool a bearing and to lengthen the life of the bearing, by a method wherein a heat pipe is embedded in a bearing housing to support the bearing of the rotary electric machine. CONSTITUTION:A heat pipe 13 is embedded in a bearing housing 9 to support a bearing 8 of a rotary electric machine at operation side and anti-operation side. That is, an evaporation portion 13a of the heat pipe 13 is embedded in a hole of the bearing housing 9 in parallel to the rotary shaft 7, and a condensation portion 13b is projected to outside of a frame 3 of the rotary electric machine 2 and a plurality of cooling fins 13c are installed and heat is radiated to the atmosphere. A heat insulating material 13d covers portion between the evaporation portion 13a and the condensation portion 13b so as to prevent heat conduction from surroundings. In this constitution, the bearing 8 is cooled and the life of the bearing 8 is lengthened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field to which the Invention Pertains] The present invention relates to a cooling structure for a bearing in a rotating electrical machine K operated at high temperatures and high speeds (for example, a generator operated directly connected to a steam turbine).

[Prior art and its problems]

Power generators that operate at high speed and are directly connected to steam turbines that use steam or gas turbines that utilize waste heat as prime movers are often used in steel or chemical plants. A typical longitudinal section of this type of rotating electrical machine is shown in Figure 1. In the figure, 1 is the prime mover, and this prime mover IK
A frame 3 of a rotating electric machine 2 is directly connected to a 7-lung portion 4, and a stator 5 is housed in the inner periphery of the frame 3.

A rotating shaft 7 of a rotor 6 corresponding to the stator 5 is integrated with a rotating shaft of a prime mover 1, and is supported by a bearing 8. The bearing 8 is usually a roller bearing made of alloy steel, and is supported by a bearing housing 9 provided on the inner periphery of the frame 3.The life of such a rolling bearing depends on the bearing load and the circumferential speed of the rotating shaft. In addition to this, it is greatly affected by the temperature of the bearing and its surroundings. The environment in which roller bearings can be used is normally limited to an ambient temperature of 100-100 degrees Celsius, and at higher temperatures, the wear resistance, fatigue resistance, creep resistance, etc. of the constituent materials of rolling bearings deteriorate. It cannot be used because it deteriorates. As a countermeasure against this high temperature, in order to keep the ambient temperature of the rolling bearing as low as possible, a labyrinth part 10 is provided on the prime mover side to prevent high-temperature steam or gas from being conducted to the rotating electrical machine side, and a heat insulating plate is installed on the rotating electrical machine side. 11 was installed to block radiant heat from the prime mover side. Furthermore, in order to reduce the amount of heat transferred from the shaft, the rotating shaft 7 is made thinner and longer to increase thermal resistance. Furthermore, the oil supply device 12 that supplies lubricating oil to the roller bearing 8 not only lubricates the bearing 8 but also cools it. Among these measures against high temperatures, the installation of a heat insulating plate 11 is recommended on the rotating electric machine side. This has the disadvantage of complicating the structure and making the axial dimension narrower. Making the rotating shaft elongated to reduce the amount of heat transfer reduces the critical speed of the shaft system, so there are some modes where the rotational speed is below the rated speed. As a result, there is a problem in that the design of rotating electrical machines becomes difficult due to the dangerous speeds involved. In addition, if the rollers are oil-lubricated, which also serves as cooling for the bearing, a complicated oil supply system equipped with a cooling function is required, and the structure of the bearing is also complicated, which increases manufacturing costs. [Objective of the present invention] In view of the above-mentioned circumstances, it is an object of the present invention to provide a rotating electric machine having a bearing structure that can withstand use even at high temperatures and high speeds and that does not require an oil temperature type lubrication device that also serves as a cooling device. purpose.

[Key points of the invention]

In a rotating electric machine that is directly connected to a prime mover that operates under high temperatures, one end of the bearing is located in a portion corresponding to the heat source of the bearing.
Provide a heat pipe exposed outside the other end or 7 frames,
[Embodiment of the Invention] Fig. 1 shows an embodiment of this invention, and Fig. 2 shows an embodiment of the invention.
4 is a diagram showing details of the bearing portion shown in the figure, and the same parts as in FIG. 3 are denoted by the same reference numerals, and explanations thereof will be omitted. FIG.

In this invention, the heat pipe 13 is embedded in the bearing housing 9 that supports the bearings 8 on the driving side and the non-driving side of the rotating electric machine 2. The details of this heat pipe 13 embedding are explained in the second section.
This will be explained based on the diagram. That is, the evaporating part 13a of the heat pipe 13 is embedded in the hole of the bearing housing 9 parallel to the rotating shaft 7, the condensing part 13b is made to protrude outside the frame 3 of the rotating electric machine 2, and a plurality of cooling fins 13c are provided. radiates heat to the atmosphere. Further, the space between the evaporating section 13a and the condensing section 13b was covered with a heat insulating material 13d to prevent heat conduction from the surroundings.

L is a working fluid 0 [Effects of the Invention] According to the present invention, a bearing that supports the bearing of a rotating electric machine operated at high speed and high temperature is cooled by cooling the bearing by embedding a heat pipe in the housing. This has resulted in a longer bearing life. In addition, there is no need for a lubrication device such as an oil lubrication system that also serves as cooling, which simplifies the overall structure and reduces manufacturing costs.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of a rotating 'wL machine which is an embodiment of the present invention, Fig. 2 is a detailed view of the bearing section in Fig. 1, and Fig. 3 is a longitudinal cross-sectional view of a rotating electrical machine with a conventional structure. 0

Claims (1)

[Claims] 1) In a rotating electrical machine that is directly connected to a prime mover that operates at high temperatures, a hydraulic fluid is sealed in a pipe whose one end is located in the area corresponding to the heat source of the bearing and whose other end is exposed outside the frame. 1. A rotating electric machine, characterized in that a heat pipe is provided, one end of which acts as an evaporator and the other end acts as a condenser, so that heat generated from a heat generating source is radiated to the atmosphere through the heat pipe.