JPS60190151A - Brushless synchronous machine - Google Patents

Abstract

PURPOSE:To preferably hold a shaft balance and to readily disassemble a brushless synchronous machine at a stopping time by coupling the machine body, a rotary rectifier and an AC exciter by the deformation due to the centrifugal force of a holding ring at a high speed rotating time. CONSTITUTION:A rotary rectifier 3 group provided between the flange 31 of the rotational shaft of a synchronous machine body and the flange 32 of the rotational shaft to an AC exciter side is coupled mechanically through a holding ring 33 with rotational shafts 2a, 2b. The flanges 31, 32 and the ring 33 vary by the centrifugal force due to the rise of the rotating speed, but the elongation of the ring 33 is large, the engagement of the ring 33 with the flanges 31, 32 varies from a loose fit to shrink fit upon rising of the rotating speed, and the centers of the shafts completely coincide with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a brushless 7171 machine that facilitates maintenance and inspection of a rotary rectifier.

[Technical background of the invention and its problems]

Recently, brushless synchronous motors have become common in order to reduce maintenance and inspection. Moreover, the number of large-capacity, high-speed machines such as turbo compressors is increasing as load machines, and synchronous motors that rotate at a high speed of 3000 rpm or more are required.

In order to achieve a brushless design, a semiconductor such as a silicon rectifying element is mounted on the rotor, but one major technical problem is how to use this mechanically relatively weak element with high reliability for a long period of time.

As mentioned above, semiconductor rectifying elements with relatively weak mechanical strength are
When mounted on a rotor that is subject to high centrifugal force, it is necessary to lower the mounting radius of the element in order to alleviate the centrifugal force. Therefore, Japanese Patent Application Laid-Open No. 133152/1983 proposes a structure in which a rotating rectifier is provided at an intermediate portion connecting the rotating shafts of the synchronous machine body and the AC exciter. This structure has difficulties in replacing the rectifying elements. That is, in order to replace the rectifying element, it is necessary to make it easy to disassemble the AC exciter. However, in order to combine the high-speed rotating synchronous machine, rotating rectifier, and AC exciter in a well-balanced manner, each rotation must be 1 liter! It is required that the fit between the two be strong. A strong fit (tight fit) is disadvantageous in terms of disassembly.

[Purpose of the invention]

The purpose of the present invention is to easily disassemble the retaining ring of the rotary rectifier provided between the synchronous machine main body and each rotating shaft of the AC exciter, when the machine is stopped, and to maintain good shaft balance during high-speed operation. The purpose of this invention is to provide a brushless synchronous machine with a structure that allows for

[Summary of the invention]

In the present invention, the rotating shaft on the synchronous machine main body side and the rotating shaft on the AC exciter side are opposed to each other at their respective flanges, and a rotating rectifier having a rectifying element housed in an annular retaining ring is arranged between them. However, in a brushless synchronous machine that combines both flanges and a retaining ring, at least the flange on the AC exciter side is externally fitted to the end of the retaining ring, so that it is a loose fit when stopped and a tight fit when in operation. By fitting them together, it is easy to disassemble because it is a loose fit when stopped, and it is a tight fit that prevents vibration from occurring during operation.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

The flange (31) of the rotating shaft (2a) on the side of the synchronous machine body (1)
) and the flange (32) of the rotating shaft (2b) on the side of the AC exciter (4). Said flange (31)
, (32) is the annular retaining ring (3) of the rotating rectifier (3).
33), the outer diameter side has a protrusion (31a) extending in the axial direction.
), (32a), and the inner diameter side of the protrusion and the axial protrusion (33a), (33b) of the retaining ring (33) are formed.
) is fitted with the so-called flange side, which is fitted as a fitting portion (34), to be fitted outwardly. By this fitting, the parts are assembled so that their central axes coincide with each other. The fitting portion (34) is a loose fit when stopped and a tight fit during operation. In other words, the fit tolerance of this fitting part (34) in a stationary state is, for example, H7 according to Japanese Industrial Standards (hereinafter referred to as JIS) on the flange side, and f6 according to JIS on the retaining ring side, so that so-called clearance fit is possible. It is being

For reference, the explanation using specific numerical values is as follows.

In case of 400φ Note that the unit of these numerical values is III Ill.

Furthermore, flanges (31), (32) and retaining ring (33)
are integrated by a bolt (35) fastened in the axial direction.

The alternating current from the alternating current exciter (7I) is guided to the mounting block (6) by a conductor (6a) passing through the flange (32) on the rotating shaft (2b) on the alternating current exciter side.

The inner diameter surface of the rotating rectifier retaining ring (33) has an absolute g
A block (6) is provided for removing the rectifying element, which is insulated from the retaining ring (33) by the block (6).
) is screwed and fixed to the rectifying element (5). This block (6) is attached with accessory elements such as a fuse and a capacitor for surge suppression as necessary, and also has the function of a fin to dissipate heat generated by the rectifying element (5). The rotary rectifier (3) converts the alternating current into direct current, and the output is transmitted through the conductor (9) built into the center hole (11) of the rotating shaft (2a) on the synchronous machine main body side. ) will be excited with direct current. The retaining ring (33) of the rotating rectifier section provided between both flanges (31) and (32) has a hole (
10) are provided, so that the cooling medium inside the retaining ring (33) can be vented. In FIG. 2, the cooling medium is supplied from the center hole (11) of the rotating shaft (2a) on the AC exciter side. With such a structure and configuration, the rotary rectifier is installed so that it can be cooled.

Next, the effect will be explained.

The rotary rectifier (3) part installed between the flange part (31) of the rotating shaft of the synchronous machine main body and the flange part (32) of the rotating shaft of the AC exciter side is mechanically connected to the retaining ring (33). It is connected to both rotating shafts (2a) and (2b). As mentioned above, the retaining ring (33) is fitted in the structure shown in FIG. 2.

In such a configuration, the flanges (31), (3
2), (The retention ring (33) etc. change due to the centrifugal force caused by the increase in rotational speed, but the annular retaining ring (3) is more disc-shaped than the disc-shaped flange (31),
Compared to the section (32), the elongation against centrifugal force is larger, and the fit between the retaining ring (33), the flange (31), and the section (32) changes from a tight fit to an interference fit as the rotational speed increases. , the centers of each axis will coincide completely.

On the other hand, in a stopped state or a state where the rotation speed is extremely low, the fitting part (34) of the flange (3+), (32) part and the retaining link (33) has a high fitting tolerance, and there is a very small gap. become a state. In this relationship, the horizontal axis represents the rotation speed, and the vertical axis represents the fitting diameter of the retaining ring and the flange portion 10: distance.
Figure 3 is an illustration of this method. In the 31st edition, the retaining ring (33) has flanges (3], ), (
If not constrained by In this case, the retaining ring (33) is completely integrated with the flanges (31) and (32), and its diameter changes as shown by the solid line under deformation stress due to centrifugal force.

In other words, by integrating the two, the rigidity of the rotating body increases and stable rotating clay motion with less vibration can be maintained.

In the extreme case of low rotational speed rotation, in the stopped state, there is a gap between the flanges (31), (32) and the retaining ring (33), so it can be easily distinguished.

The rotary rectifier (3) has a built-in semiconductor rectifying element (5), but its electrical performance may deteriorate due to factors such as overcurrent and overvoltage, and it may need to be replaced. Flange (31) in the stopped state.

If there is a slight gap between (32) and retaining ring (33), the flange (31), (32) and retaining ring (
33) If you remove (35) from the pole 1 that connects the gap, you can simply move one of the flanges (31) and (32) in the axial direction, without using a special direct tool. Flange (3]).

There is no need to check the (32) part and unfit the flange (
31), (32) and the retaining ring (33) can be disassembled.

Therefore, it is the same as brushless! II] When the machine is used as an electric motor, this means that the rectifying element (5) etc. can be replaced in a short time at the site where the motor is installed, and reassembly after replacement can be completed in a short time because the fit is loose. In other words, the time required for disassembly and reassembly for replacement (motor stop time) can be shortened, and conversely, the operating time of the motor and, by extension, the operating rate of the entire plant can be increased. Needless to say, this will lead to improvements in plant productivity and reliability.

Another effect is that the retaining ring (33
) completely adheres to and integrates the flanges (31) and (32), increasing the rigidity of the rotating body, allowing stable rotation with less vibration, and improving reliability during operation. connected to.

In another embodiment shown in FIG. 4, the fitting part (34) is provided on the rotary rectifier (3) and AC exciter (4) sides, and the synchronous machine body (1) side of the rotary rectifier (3) is Retaining ring (33
) and a flange (31) are formed into one body.

In this way, the fitting of the AC exciter (4), which is lighter and easier to disassemble and move than the synchronous machine body (1), can be made looser, so that the rectifying element (5) can be easily replaced, disassembled, and reassembled. , in addition to having the same effects as the above embodiment, the fitting part (3
]), it has the advantage of being easier to work with than the previous embodiment.

〔Effect of the invention〕

As explained above, according to the present invention, the rotary rectifier is attached to the retaining ring outer diameter surface on the inner diameter surface of the protrusion provided on the outer periphery of the flange portion between the synchronous machine main body connecting them and both rotating shafts of the AC exciter. When rotated at high speed, the retaining ring deforms due to centrifugal force, creating an interference fit that integrates with the flange, allowing stable high-speed rotation. Furthermore, since there is a slight gap between the fittings in the stopped state, the following effects can be obtained particularly when replacing a damaged rectifying element of a rotary rectifier.

( ], ) The retaining ring and flange can be unfitted in a short time without heating or using special tools. In particular, the thermal type TP is applied to a thermally weak rectifying element without causing deterioration of a healthy rectifying element.

(2) Disassembly and reassembly for replacing rectifying elements etc. is short 11,
What can be done between T is to shorten the stop time of the brushless synchronous machine,
In other words, this will lead to improvements in operating time and overall plant utilization rate.

(3) During high-speed operation, the retaining ring rotates in alignment with the center of rotation, so high-speed rotation can be performed stably, and the rectifying element, which is vulnerable to vibration, does not suffer mechanical deterioration, and the entire machine This leads to improved reliability.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional elevational view of the main part showing one embodiment of the brushless synchronous machine of the present invention, Fig. 2 is an enlarged vertical sectional elevational view of the upper half showing the vicinity of the rotating rectifier in Fig. A curve diagram showing the relationship between joint radius dimension and rotation speed. FIG. 4 is a vertical sectional elevational view of the upper half showing the main parts of another embodiment. 1...Synchronous machine main body 2a...Synchronous machine main body side rotating shaft 2b
... AC exciter side rotating shaft 3 ... Rotating rectifier 31.32 ... Flange 33 ... Retaining ring 34 ... Fitting part 35 ... Bolt 4 ...
・AC exciter 5... Rectifying element Figure 1 Figure 2

Claims (1)

[Claims] A rotating shaft on the synchronous machine main body side and a rotating shaft on the AC exciter side are opposed to each other at respective flanges provided on both sides, and a rotating rectifier having a rectifying element housed in an annular retaining ring is disposed between them.
In a brushless synchronous machine that combines both flanges and a retaining ring, at least the flange on the AC exciter side is externally fitted to the end of the retaining ring, so that it is a snug fit when stopped and an interference fit when operating. A brushless synchronous machine characterized by mating.