JPH02303340A - Claw-pole type synchronous generator - Google Patents

Abstract

PURPOSE:To prevent the mixture of dust and heat into the exhaust gas of the title generator and improve the cooling performance by supplying a low-temperature sealing gas from the space between a turbine and thrust bearing and cooling principal internal constituents with a gas discharged from a compressor. CONSTITUTION:A gas which is supplied to the sealing gas supplying hole 25b in the housing 25 of a thrust bearing 20 from the discharge pipe 27 of a compressor 12 through a sealing gas supplying pipe 28 and absorbs heat from the housing 25 tends to flow to a turbine 11 side and into this generator, but the flow rate of the gas flowing into the generator is suppressed to an extremely small quantity, since the gas receives a very strong flow resistance due the very narrow gap between a thrust bearing 20 adjacently provided on the generator side and inner thrust plate 22 and the gas from the thrust bearing 20 flows toward the inner periphery from the outer periphery, the flow rate of the gas to the inside of the generator being very small. Accordingly, most of the gas which becomes high in temperature due to the absorbed heat is made to flow to the turbine 11. Therefore, conduction of the heat to the generator can be reduced and, at the same time, the mixture of dust into the exhaust gas can be prevented.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a claw-pole generator equipped with a turbine and a compressor at both ends of a rotating shaft, and particularly relates to a claw-pole generator equipped with a turbine and a compressor at both ends of a rotating shaft. This invention relates to a claw-pole synchronous generator that aims to prevent dust from entering the inside of the bearing and to improve cooling performance inside the generator.

(Prior Art) FIG. 2 is a longitudinal cross-sectional view showing the principle structure of a conventional claw-pole generator, and FIG. 3 is a cross-sectional view taken along line A-A.

The generator rotor 1 is supported by rolling bearings 2 and bearing brackets 3 provided at both shaft ends. Bearing bracket 3
is fixed to the stator frame 4, a stator core 6 is fitted in the center of the stator frame 4, and an electric machine pre-winding m5 is housed inside the stator core 6.

The rotor 1 of the claw-ball type synchronous generator is divided into two parts in the axial direction, and as shown in FIG. Manufactured by welding etc.

The rotor 1 having such two-pole permanent magnets becomes a mechanically rigid rotating shaft and is suitable for an ultra-high speed rotating body.

On the other hand, the field winding 8 is housed within both ends of the stator frame 4 so as to form a magnetic path 9, and direct current is passed therethrough to generate electric power.

If a low-ball synchronous generator is used in a Playton cycle power generation system as shown above.

The turbine and compressor are mounted on the generator rotor shaft. For example, in the Preyton cycle power generation system for space thermal power generation, the generator is required to be ultra-compact, lightweight, highly efficient, and long-term reliable, and active magnetic bearings or gas bearings are the most popular bearings that meet these requirements. It will be done.

FIG. 4 shows a longitudinal cross-sectional view of a Preyton cycle claw-pole synchronous generator using current gas bearing technology.

Next, this configuration will be explained.

A turbine 11 and a compressor 12 are installed at both ends of the generator rotor lO. Armature winding frame 1
3 is fitted with an iron core 14, and an armature winding 5 is fitted inside this core 14.
is stored. A field winding frame 15 is fixed to each end of the armature winding frame 13, and a magnetic field member s8 is housed inside the field winding frame 15.

A bearing housing 16 is attached to the end face of the magnetic field winding frame 15 on the turbine side 11, and a tilting pad radial bearing device consisting of a pad 17, a pivot 18, and a fixing nut 19 is mounted on the inner peripheral side of the bearing housing 16. is set up.

On the other hand, the field winding frame 15 on the side of the compressor 12
As shown in Fig. 5, on the end face of the
It is equipped with a thrust bearing device consisting of two parts. Furthermore, a turbine 11 is disposed on the side of the compressor 12 of the spacing piece 21.
The same tailing pad radial bearing device as on the side is installed. Also, turbine 11 and compressor 1
A labyrinth seal 23 is installed between each of the two tailing pad radial bearing devices.

(Problems to be Solved by the Invention) When the low-ball type synchronous generator as described above is employed in a Preyton cycle type generator system, the problems are listed below.

(1) The exhaust gas that drives the turbine has a temperature of several hundred degrees ('C).
), there is a large amount of heat infiltration into the bearing and the generator, resulting in large thermal deformation and expansion of the bearing.
Gas bearing performance deteriorates. Further, due to an abnormal temperature rise in the armature winding and field winding of the generator, an electrical accident is likely to occur due to large burnout or deterioration of one winding.

■ Dust is mixed in the exhaust gas that drives the turbine, and when it enters the generator, the sliding clearance of the gas bearing is extremely small, causing damage to the bearing and a major seizure accident.

■ Normal labyrinth seals have low flow resistance in the axial direction, so the amount of exhaust gas leaking into the generator is always large due to the internal pressure difference between the back of the turbine and the generator.

2) At ultra-high speeds, the loss generated in the generator rotor and bearings is large, so if only the natural convection inside the generator is used, heat dissipation to the outside of the generator is poor, and the temperature of various parts inside the generator becomes abnormally high.

The present invention was developed in view of the problems of the prior art as shown in (ω) above, and specifically prevents heat from entering from the turbine side and dust from entering, and further improves the cooling performance inside the generator. The object of the present invention is to provide an improved claw-ball type synchronous generator.

[Structure of the invention]

(Means for solving the problem) As a means to solve the problem described in item 1, the shaft end has a turbine and a compressor, the radial bearing uses a tilting pad type gas bearing, and the thrust bearing has a spiral groove. Claw pole type rule 9 using gas bearing! In an electric machine, a thrust bearing is installed between a turbine and a radial bearing. Further, a cooling seal groove and a seal air supply hole are provided in the thrust housing provided between the turbine and the thrust bearing, and the air supply hole and the discharge pipe of the compressor are connected by a seal air supply pipe. Furthermore, a cooling gas supply hole is provided in the labyrinth seal provided on the compressor side, a ventilation hole is provided in the field frame, an axial ventilation hole is provided in the core support outer cylinder, and a radial duct is provided in the center of the core.

The exhaust hole provided in the thrust bearing housing and the inlet of the compressor may be connected by an exhaust pipe.

(Function) Since the present invention is configured as described above, it suppresses the mixture of exhaust gas from the turbine and heat intrusion into the generator, and
In addition, the amount of gas used for sealing and cooling leaking into the generator is suppressed, improving the cooling performance inside the generator, making it possible to provide a low-pole synchronous generator that is highly reliable and can be made smaller and lighter. .

(Example) Hereinafter, an example of the present invention will be described with reference to FIG.

Note that the same reference numerals are given to the parts described in the prior art in FIGS. 2 to 5, and the description thereof will be omitted.

In FIG. 1, pads 17 are arranged by spherical pivots 24 on the inner peripheral surfaces of circumferential field winding frames 15 on the turbine and compressor sides. Further, the thrust bearing 20 is installed on the turbine side. A thrust bearing housing 25 supporting the thrust bearing 20 is directly fixed to the field frame 15 on the turbine 11 side.

This thrust bearing housing 25 has a cooling seal groove 25.
a is processed, and a seal air supply hole 25b is further provided,
A seal air supply pipe 28 is connected between the seal air supply hole 25b and the discharge pipe 27 of the compressor casing 26, and a seal amount adjustment valve 29 is provided in the middle. Also, the thrust bearing 2 of this thrust bearing housing 25
An exhaust hole 25c is machined in the installation part of 0, and this exhaust hole 25c and the inlet of the compressor casing 26 are connected by an exhaust pipe 30, and a cooling amount adjustment valve 31 is installed in the middle. On the other hand, a labyrinth seal 32 is connected and fixed to the field frame 15 on the compressor 12 side. This labyrinth seal 32 has cooling gas supply holes 32.
0 and field frame 1 in which a is provided in large numbers on the circumference
A ventilation hole 15a is machined in the turbine 11.
A large number of radial ventilation grooves 15b are provided on the surface of the thrust bearing 20 of the field frame 15 on the side.

A large number of axial ventilation grooves 33a are machined on the outer peripheral surface of the core support cylinder 33.

In addition, a radial duct 14a is provided in the middle of the stack of iron cores 14.
will be established.

Next, the effect will be explained.

First, by incorporating the pad 17 inside the field frame 15, the structure of the tailing pad radial bearing device is greatly simplified compared to the prior art.

The discharged gas from the compressor 12 has a slightly higher discharge pressure than the gas from the turbine 11, and its temperature is extremely low.

For this reason, the air is supplied from the discharge pipe 27 of the compressor 12 through the seal air supply pipe 28 to the seal air supply hole 25b of the thrust bearing housing 25. This low temperature gas is ejected onto the shaft surface of the generator rotor 10 through the cooling seal groove 25a. At this time, the turbine 11 is extremely hot, and the thrust bearing housing, gear 25 and generator rotor 1
Heat is transferred from 0 to the generator side, but the cooling seal groove 25
Since a is provided, the thermal resistance in the axial direction is large, and since low-temperature gas is supplied therein, the amount of heat transferred to the generator side can be reduced.

Furthermore, since low-temperature gas is also ejected to the generator rotor 10, the amount of heat transferred from the generator rotor 10 to the inside of the generator can be reduced. The heated gas supplied from the seal air supply hole 25b tries to flow into the turbine 11 side and the inside of the generator, but the thrust bearing 20 is adjacent to the generator side. Since the gap between the inner plate 22 is very small at about 10/ffi, the flow resistance is very large, and the gas flow of the thrust bearing 20 with the spiral groove is structured to flow from the outer circumference 1 toward the inner circumference. For this reason, the flow rate of gas into the interior of the stain machine is extremely small, and most of the high temperature gas flows out of the turbine 11.

Therefore, heat infiltration into the inside of the generator can be reduced, and dust can be prevented from entering the exhaust gas.

The supply amount of this seal is controlled by a seal amount m regulating valve 29.

Further, cold gas is supplied from the cooling bus air supply hole 32a provided in the labyrinth seal 32 due to the pressure difference between the inlet and outlet of the compressor 12. 20 Gas flows as shown by the arrow in Figure 1. Tailing pad radial bearing 17 on compressor 12 side → armature winding 5, field winding 8 → axial ventilation groove 33a of iron core j holding outer cylinder 33, radial duct 14a of iron core 14 → turbine 1
1 side armature winding 5 field winding 8 → turbine it side tailing gear radial bearing 17 → thrust bearing 2
0 bottom surface, Todomari) 1 After cooling the element that becomes the temperature,
The air is returned to the inlet of the compressor casing 26 from the exhaust hole 25c provided in the thrust 1 to the bearing housing convex ring 26 via the exhaust pipe 3o.

Note that this cooling amount is controlled by a cooling amount adjustment valve 31.

〔Effect of the invention〕

As explained above, gas bearings are used to support the generator rotor, and a thrust bearing device is installed on the turbine side.
Cool sealing gas is supplied from between the turbine and the thrust bearing device, and the main elements inside the generator are cooled by the discharged gas from the compressor, thereby eliminating the dust in the exhaust gas and the inside of the generator. It is possible to prevent contamination and heat contamination and improve the cooling performance inside the generator.

This makes it possible to provide an ultra-high-speed claw-pole synchronous generator that is highly efficient, compact, lightweight, and has excellent long-term reliability.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view of a claw-pole synchronous generator showing an embodiment of the present invention, Figs. 2 and 3 are principle diagrams of a claw-pole synchronous generator according to the prior art, and Fig. 4 is a gas bearing. FIG. 5 is a longitudinal cross-sectional view of a conventional claw-pole synchronous generator when the generator is adopted, and FIG. 5 is a front view of the spiral grooved thrust bearing installed in FIG. 4. 4... Stator frame 10... Generator rotor 1
1... Turbine 12... Compressor 13... Armature winding frame 14a... Radial duct 15... Field winding frame 17... Pad 19... Thrust bearing 28... Seal Air supply pipe 32a...Cooling gas supply hole 33a...Axial ventilation groove Representative Patent attorney Noriyuki Chika Ken Yudo Daishimaru Ken Figure 2 Figure 3

Claims (1)

[Claims] In a claw-pole synchronous generator having a turbine and a compressor at the shaft end, using a tilting pad type gas bearing as the radial bearing, and using a spiral grooved gas bearing as the thrust bearing, ) A claw-pole synchronous generator characterized by a thrust bearing installed between a turbine and a radial bearing. (2) A cooling seal groove and a seal air supply hole are provided in the thrust housing provided between the turbine and the thrust bearing,
This claw-pole synchronous generator is characterized in that the air supply hole and the discharge pipe of the compressor are connected by a sealed air supply pipe. (3) Provide a cooling gas supply hole in the labyrinth seal provided on the compressor side, provide a ventilation hole in the field frame, provide an axial ventilation hole in the core support outer cylinder, provide a radial duct in the center of the core, A claw-pole synchronous generator characterized by an exhaust pipe connecting the exhaust hole provided in the thrust bearing housing and the compressor inlet.