JP2006214341A - Turbo rotating equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a turbo rotating equipment in which problems that the fitting of a turbo blade to a rotating shaft is worsened by centrifugal force due to high speed rotation and repetition of temperature difference such as high temperature and normal temperature, and malfunction is caused by the dislocation at a contact surface of the turbo blade with the rotating shaft are solved. <P>SOLUTION: A coupling 14 is secured to the upper step in the rotating shaft 4. The coupling 14 has an annular part with two different diameters in cross section. The rotating shaft 4 is fitted into an inner hole with minor diameter. An inner peripheral surface 7S of an axial end (lower part) of the turbo blade 7 is fitted into the annular part of major diameter. The fitting is a tight fit. The turbo blade 7 does not cause a contact dislocation, etc., for the coupling 14 owing to the structure. The coupling 14 is fitted in a central hole 8H of a seal member 8. Thereby, a minor diameter outer peripheral surface 14F of the coupling 14 is in proximity and faces the central hole 8H of the seal member 8, so that a seal mechanism is formed between both. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a turbo rotating device applicable to, for example, a blower as an electric compressor for gas circulation in a gas laser oscillator device.

  For example, in the case of a flow type carbon dioxide gas laser oscillator device, it is compressed while flowing a mixed gas of carbon dioxide gas and other gas and supplied to the laser oscillator to resonate, and a gas circulation circuit is configured in the device. Yes. As a blower as one element in the configuration of the circulation circuit, a turbo rotating device that rotates a turbo blade at high speed to compress gas and supplies the gas to a laser oscillator is used.

  In this type of turbo rotating device, a turbo blade is rotatably disposed above a housing, a mechanism for compressing and discharging gas is provided, and a motor for rotating the turbo blade at a high speed is disposed below. It is installed. The rotating body including the rotor of the motor, the turbo blade, the rotating shaft, and the like is pivotally supported by a mechanical bearing and is provided with lubricating means using oil. Therefore, although oil mist is generated, a method of exhausting with a vacuum pump is employed so that the oil mist is not discharged together with gas compression (see Patent Document 1).

  The configuration of this turbo rotating device is as shown in FIG. FIG. 5 is a longitudinal sectional view schematically showing that a turbo blade 7 is rotatably disposed on the inside of the housing 1 and a motor 2 for rotating the turbo blade 7 at a high speed is disposed below the housing 1. Both are connected by the rotating shaft 4. The motor 2 is composed of an electrode coil 2K fixed on the housing 1 side and a rotor 2M fixed to the rotary shaft 4 corresponding to the electrode coil 2K. Electric energy is supplied to the electrode coil 2K from the inverter 3. Is supplied.

The rotary shaft 4 is rotatably held with respect to the housing 1 via an upper bearing 5 and a lower bearing 6. A turbo blade 7 is fixed to a mounting shaft 4 </ b> S formed above the rotary shaft 4. Yes. A rotating body including the motor 2, the rotor 2M, and the rotating shaft 4 is held by an upper bearing 5 and a lower bearing 6 that constitute a bearing mechanism. The upper bearing 5 and the lower bearing 6 are disposed in the motor chamber M. When the turbo blade 7 is driven to rotate at high speed by the motor 2, the gas is sucked from the inlet 1K, compressed, and exhausted 1H. More discharged. The gas compression chamber C is formed from the intake port 1K to the exhaust port 1H. The gas from the exhaust port 1H is supplied to a laser oscillator (not shown) through a gas circulation circuit (not shown) as described above.

  As shown in FIG. 5, the rotary shaft 4 has a hollow hole 4H formed on the shaft center. The lower part of the hollow hole 4H has a tapered shape with the inner hole expanding upward, and the lower part is It is immersed in the oil L for lubrication. Accordingly, the lubricating oil L entering the lower region of the hollow hole 4H moves upward in the hollow hole 4H under the action of the centrifugal force caused by the rotation of the rotary shaft 4, and this action causes the hollow hole 4H to move upward. 4H causes the pump function. Thus, the lubricating oil L is sequentially sent upward and discharged outward from the injection hole 4T to cool the motor 2 and lubricate the upper bearing 5 and the lower bearing 6. The lubricating oil L that has been lubricated and cooled is again stored in the lower oil tank 1Y, sucked up again, and circulated.

  In this way, the lubricating oil L circulates to lubricate the upper bearing 5 and the lower bearing 6. By this lubrication, especially in the motor chamber M, sprayed oil L (oil mist) exists and floats. It will be. The presence of the spray-like oil L in the motor chamber M improves the lubrication in the upper bearing 5 and the lower bearing 6, but when this oil mist flows into the gas compression chamber C, it flows into a laser oscillator or the like, causing laser oscillation. Reduce functionality.

  Therefore, the gas compression chamber C and the motor chamber M are blocked by the seal portion S in the partition wall portion made of a member integral with the housing 1 or the housing 1. That is, the housing 1 is provided with a penetrating portion in a range in which the rotating shaft 4 can pass through without contact at a position above the upper bearing 5, and a seal portion S is formed in cooperation with the rotating shaft 4. For example, a labyrinth seal shown in the illustrated example is applied to the seal portion S. In the seal portion S by the labyrinth seal, the gap between the rotating shaft 4 and the penetrating portion is usually set to several tens of microns. In addition to the labyrinth seal, a gas seal set to a small parallel gap of several tens of microns is also employed.

  On the other hand, the motor chamber M is evacuated to vacuum by an externally provided vacuum pump (not shown) via an exhaust pipe R. This is to prevent the motor chamber M from being filled with the mist of the lubricating oil L and leaking into the gas compression chamber C from the small gap in the seal portion S as described above.

  As described above, in the turbo rotating device used for the laser oscillator, the presence and countermeasure of the oil L mist are important, but the presence of the oil L that is the source of the mist cannot be ignored. In particular, it is necessary to prevent the oil L discharged from the injection hole 4T of the rotating shaft 4 from reaching the upper seal portion S as much as possible. Therefore, the device which installs a partition board above the upper bearing 5 so that it may mention later is proposed.

  That is, FIG. 4 is a longitudinal sectional view schematically showing the configuration of the turbo rotating device in FIG. 5, particularly the configuration of the coupling relationship between the rotating shaft 4 and the turbo blade 7. The configuration of FIG. 4 is different from the configuration of FIG. 5 in that the upper bearing 5 is held and the seal member 8 constituting the seal portion S is placed on the upper surface of the bearing holding member 9. is there. 8A is a through hole drilled for the rotating shaft 4 penetrating the seal member 8, and 9H is a through hole drilled in the central portion of the bearing holding member 9. The seal member 8 and the bearing holding member 9 are fixed to the housing 1 via bolts 11 shown in FIG. Reference numeral 16 denotes the partition board described above. The partition 16 is fitted on the rotary shaft 4 and is disposed between the upper bearing 5 and the seal member 8. 4 that have the same reference numerals as those in FIG. 5 have the same functions as those in FIG. 5, and a detailed description thereof will be omitted.

In such a configuration, the seal member 8 is provided with a through hole 8 </ b> A and has a certain gap with the rotary shaft 4. By reducing this gap, it is possible to reduce the oil L supplied to the upper bearing 5 from flowing into the seal portion S.
Japanese Unexamined Patent Publication No. 2000-209815 (page 1-3, FIGS. 1-8)

  The blower that requires high compression flow rate performance will be described with reference to FIG. 4. Since the turbo blade 7 has a large diameter and is operated at a higher speed, the turbo blade 7 has a centrifugal force during rotation. Considering the stress generated inside and the weight reduction to increase the rigidity of the rotating body and the high temperature of the turbo blade 7 due to gas compression and motor loss, etc., the material selection of the turbo blade 7 is important and essential first of all. Matters. Therefore, materials such as lightweight and high-strength titanium or aluminum alloy forgings are generally used. Further, the turbo blade 7 and the rotary shaft 4 are coupled to each other in the center of the turbo blade 7 with a hole through which the rotary shaft 4 passes, and the rotary shaft 4 side corresponds to the end face of the turbo blade 7 during assembly. Thus, the rotary shaft 4 is provided with a different diameter portion, the mounting shaft 4S at the upper end of the rotary shaft 4 is provided with a screw, and the upper surface of the turbo blade 7 is held and fixed with a nut or the like.

  When titanium material is used for the turbo blade 7, the material cost and processing cost are high, and in the case of aluminum material, the difference in linear expansion coefficient from the material of the rotating shaft 4 (usually steel material) is large. Due to the temperature difference, the contact surface between the turbo blade 7 and the rotating shaft 4 is displaced, and the center of the turbo blade 7 is deviated from the core of the rotating shaft 4 by long-term operation in such a state. May be ranked. In addition, when the turbo blade 7 has a large diameter due to a large elastic coefficient, if the contact surface of the rotating shaft 4 is deformed slightly unevenly, it is relatively displaced as described above by repeated start and stop. There are things to do. The misalignment between the turbo blade 7 and the rotating shaft 4 causes an increase in the unbalance of the rotating body, leading to excessive vibration and bearing failure. For this reason, in order to achieve a blower that requires a high compression ratio, a plurality of stages of small-diameter turbo blades 7 must be provided.

  On the other hand, with respect to the seal mechanism that seals between the rotary shaft 4 and the seal member 8 serving as a partition wall partitioning the gas compression chamber C and the motor chamber M, a through-hole in the seal member 8 is caused by vibration of the rotating body during operation. In order to prevent the contact between the 8A side and the rotating shaft 4, the concentricity of the through hole 8A with the rotating shaft 4 side is strongly demanded and severe. For this reason, it is easy to check and adjust the concentricity when assembling the turbo rotating device. is not. In addition, when determining by fitting accuracy between parts, the required values of concentricity and machining accuracy of a plurality of parts concerned become severe, and on the other hand, a limit is set for reducing the gap.

  Therefore, when the gap is widened, the amount of vacuuming of the seal portion S in operation increases, and when used as a blower of a laser oscillator, the amount of laser gas consumed increases and the running cost increases. Further, when this seal mechanism is constituted by a labyrinth seal, the machining is complicated, and machining a part of the rotating shaft 4 is a problem in terms of cost and operation, and must be a separate part. It is a fact.

In order to solve the above problems, a turbo rotating device provided by the present invention has an annular portion into which an outer peripheral surface on one end side in the axial direction of a turbo blade can be inserted, and is inserted into the rotating shaft through a central through hole. A coupling that includes a fixed coupling, and that connects the turbo blade to the rotating shaft by fitting and fixing the coupling to the rotating shaft, and inserting the one end of the turbo blade into the annular portion of the coupling. It is.
In the present invention, the coupling material is a material having a linear expansion coefficient comparable to that of the rotating shaft or the partition board.

  In the turbo rotating device provided by the second aspect of the present invention, a sealing mechanism provided between the compression member and the sealing member as a partition wall that partitions the motor chamber is provided between the coupling and the sealing member. Is. Specifically, the seal mechanism is provided between the outer peripheral surface of the coupling and the seal member, and the seal mechanism is configured by a labyrinth. Therefore, the coupling tag can suppress deformation in the vicinity of the inner diameter at one axial end (base) of the turbo blade, and the center of the turbo blade is deviated from the center of the rotating shaft even if the start and stop cycles are repeated. This can be suppressed.

  Further, by using the same coupling material as that of the rotating shaft or the like, it is possible to suppress a shift in relative position due to a temperature rise. The assembly adjustment work of the centering with respect to the rotating shaft on the stationary side of the seal portion is facilitated without the coupling and the turbo blade being assembled. Further, when the labyrinth seal structure is adopted, the coupling can have two functions, which is effective in reducing the number of parts.

A single-stage blower provided with a large-diameter turbo blade, and the highly reliable high-compression turbo rotating device can be provided without causing the shaft center of the turbo blade to be displaced from the shaft center of the rotating shaft.
Moreover, the sealing function of the partition part between the compression chamber and the motor chamber is improved, and the running cost can be suppressed.

The first feature of the present invention is that, in the configuration in which the turbo blade is attached to the rotating shaft, the outer peripheral surface of the axial end portion of the turbo blade is surrounded (enclosed) by the coupling, so that a temperature difference due to rotation / stop occurs. However, there is no deviation at the contact surface between the turbo blade and the rotating shaft.
Furthermore, the second feature of the present invention is that a seal mechanism is provided between a seal member, which is a partition wall partitioning the compression chamber and the motor chamber, and the coupling.
Further, the third feature of the present invention is that the coupling and the material such as the rotating shaft to which the coupling is fixed have the same or the same linear expansion coefficient, thereby causing a deviation between the two due to expansion during temperature rise. It is a point that I did not let you.
Therefore, the best mode of the present invention is a turbo rotating device having both of these three characteristics. That is, a turbo blade is attached by a coupling, and a sealing mechanism is formed between the outer peripheral portion of the coupling and a sealing member. Moreover, the seal mechanism is a labyrinth seal structure that can be sealed in a non-contact manner, and the linear expansion coefficients of the coupling and the rotating shaft are the same or the same.

This embodiment is shown in FIG. FIG. 1 is an enlarged cross-sectional view particularly showing only the connecting portion between the turbo blade 7 and the rotating shaft 4. FIG. 1 also shows a bearing mechanism for the rotating shaft 4 and a sealing mechanism for the rotating shaft 4 and the seal member 8.
That is, as shown in FIG. 1, the turbo blade 7 is provided with a central hole 7H at the center thereof, and the mounting shaft 4S of the rotating shaft 4 is penetrated through the central hole 7H. A nut 13 is screwed onto the upper end of the mounting shaft 4S via a washer 12, and the turbo blade 7 is fixed. As shown in the figure, the turbo blade 7 is fixed to the step portion of the rotating shaft 4 and the mounting shaft 4S having a smaller diameter than the rotating shaft 4 with a certain distance in the axial direction.

  In the configuration as described above, the coupling 14 is fixed to the rotary shaft 4 at the position of the upper step. This coupling 14 has two different-diameter annular portions in cross-sectional shape, and the rotary shaft 4 extends through a small-diameter inner hole. The large-diameter annular portion has an axial end (downward) of the turbo blade 7. The outer peripheral surface 7S is inserted. This insertion is an interference fit. With such a configuration, the turbo blade 7 does not cause contact displacement with respect to the coupling 14 or the like. In FIG. 1, the seal member 8 is mounted on the bearing holding member 9 in the form of surface bonding, and a coupling 14 is provided through the central hole 8H. Moreover, the material of the coupling 14 and the material of the rotary shaft 4 are set to have the same or similar linear expansion coefficients, and therefore, even if the coupling 14 and the rotary shaft 4 expand due to a temperature rise, they are displaced. As a result, the turbo blade 7 and the rotating shaft 4 are not displaced, and the relationship between the two is guaranteed.

Accordingly, the small-diameter outer peripheral surface 14F of the coupling 14 is close to and opposed to the central hole 8H of the seal member 8, and a seal mechanism is formed therebetween. When the coupling 14 and the turbo blade 7 are fastened to the rotating shaft 4 in the assembly work of the turbo type rotating device, the center hole 8H of the seal member 8 is positioned so that the axial deviation can be suppressed to a minute with respect to the rotating shaft 4. The seal member 8 is fixed to the bearing holding member 9. At this time, the outer periphery of the coupling 14 becomes a small-diameter outer peripheral surface 14F of the seal gap, and the coupling 14 can be secured sufficiently before the positioning of the center hole 8H on the stationary side of the seal portion S before the coupling 14 is assembled. It can be adjusted with high accuracy. Specifically, as shown in FIG. 2, a labyrinth groove 8M is formed on the inner peripheral surface of the center hole 8H of the seal member 8 that is close to and opposed to the small-diameter outer peripheral surface 14F of the coupling 14, and the coupling 14 and the seal member 8 A labyrinth-type seal mechanism is formed between the two. It is non-contact and exhibits a sealing mechanism with a high-speed rotating body.
In the embodiment shown in FIG. 1, the divider 16 is interposed between the coupling 14 and the upper bearing 5. The above is an example in which the coupling 14 is not fixed to the rotating shaft 4, the partition plate 16 is fixed to the rotating shaft 4, and the partition plate 16 and the coupling 14 are joined. As a method of joining, there is a method in which the coupling 14 and the partition 16 are fixedly joined by fastening a nut 13 screwed into the upper end of the mounting shaft 4S. In this case, the linear expansion coefficients of both materials are set to be the same or approximately the same in order not to cause a shift between the two due to expansion during temperature rise.
As yet another modification, there is a method in which the upper portion of the rotary shaft 4 is an enlarged-diameter rotary shaft that expands to the outer diameter of the coupling 14, and the coupling 14 is fixed to the upper end of the enlarged-diameter rotary shaft. it can. Further, the divider 16 may be omitted. In this case, by making the linear expansion coefficients of the materials of the coupling 14 and the rotary shaft 4 equal, no deviation occurs between them. The present invention includes these.
1 and 2, parts indicated by the same reference numerals as those shown in FIGS. 5 and 4 have the same or similar functions as those in FIGS. 5 and 4, and detailed description thereof is omitted. The labyrinth groove 8M in FIG. 2 may be provided on the coupling 14 side.

  This embodiment is shown in FIG. FIG. 3 is an enlarged longitudinal sectional view showing a joint portion between the turbo blade 7 and the rotating shaft 4 as in FIG. As shown in FIG. 3, the present embodiment is an example in which the coupling between the coupling 15 and the end in the axial direction (downward) of the turbo blade 7 is performed by a taper mechanism. A tapered portion 7T is formed at the axial center end (the lower end in the figure) of the turbo blade 7, and a coupling shaft 4S formed above the rotary shaft 4 has a V-shaped coupling on the inner peripheral surface of the annular portion. 15 is inserted and fixed. The inner peripheral surface of the annular portion of the V-shaped coupling 15 forms an upwardly open tapered surface 15T, and the tapered portion 7T of the turbo blade 7 is press-fitted into the tapered surface 15T.

Then, by fastening the nut 13 screwed into the upper end of the mounting shaft 4S, the turbo blade 7 is pressed downward, and the tapered portion 7T is press-fitted into the tapered surface 15T of the coupling 15. In this way, the turbo blade 7 is free from contact misalignment. 3, parts indicated by the same reference numerals as those shown in FIGS. 5 and 4 have the same or similar functions as those shown in FIGS. 5 and 4, and detailed description thereof will be omitted.
Further, in this embodiment, the coupling 15 and the rotating shaft 4 are connected by fixing the partition 16 to the rotating shaft 4 and fixing the partition 16 and the coupling 15 together. Further, the upper part of the rotating shaft 4 can be enlarged in diameter so that the coupling 15 can be fixed above it. Further, the divider 16 may be omitted. Also in the embodiment of FIG. 3 including these, the material of the coupling 15 and the material of the rotary shaft 4 or the partition 16 are set to have the same or the same linear expansion coefficient.

  The features of the turbo rotating device provided by the present invention are as described in detail above, but are not limited to the above and illustrated examples. In particular, for the couplings 14 and 15, the embodiment of the annular shape having two inner peripheral surfaces with different inner diameters has been shown. However, a circumferential rib is formed on the outer periphery of the large-diameter annular portion to be reinforced. You can also. In the illustrated example, the partition plate 16 is welded to the rotating shaft 4, but a screwing method or a spline connection may be used. Or it can also be made detachable by screwing. The couplings 14 and 15 can also be fixed to the rotary shaft 4 via the partition board 16. In this case, the partition plate 16 is fixed to the rotating shaft 4 and the coupling 14 is placed so that the bottom surface thereof is joined to the top surface of the partition plate 16. In such a configuration, the linear expansion coefficients of the coupling 14 and the divider 16 are set to the same level. As a result, no deviation occurs between the two even when the temperature rises. The present invention includes such an embodiment. The material of the couplings 14 and 15 can also be a material having a strength other than those described above, and is not limited to the above materials. Furthermore, the present invention can also be applied to a turbo-type rotating device having the same total length of the rotating shaft.

It is a longitudinal cross-sectional view which shows the structure of the principal part of the turbo type rotating apparatus which this invention provides. It is a longitudinal cross-sectional view which expands and shows the principal part of the turbo type | mold rotary apparatus which this invention provides. It is a figure which shows the structure of the conventional turbo type | mold rotary apparatus. It is a figure which shows the structure of the attachment part of the turbo blade of the conventional turbo type | mold rotary apparatus. It is a figure which shows schematically the structure of the conventional turbo type | mold rotary apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing 1K Intake port 1H Exhaust port 1Y Oil tank 2 Motor 2K Electrode coil 2M Rotor 3 Inverter 4 Rotating shaft 4H Hollow hole 4S Mounting shaft 4T Injection hole 5 Upper bearing 6 Lower bearing 7 Turbo blade 7H Central hole 7S Outer surface 7T Taper Part 8 Seal member 8A Through hole 8H Center hole 8M Labyrinth groove 9 Bearing holding member 9H Through hole 11 Bolt 12 Washer 13 Nut 14 Coupling 14F Small-diameter outer peripheral surface 15 Coupling 15T Tapered surface 16 Partition plate C Gas compression chamber L Oil M Motor Chamber S Seal part R Exhaust pipe

Claims (7)

  In a turbo type rotary device provided with a turbo mechanism that has a turbo mechanism attached to a rotary shaft that is rotationally driven by a rotary drive source and performs a pump function by the rotation of the turbo blade, an outer peripheral surface on one end side in the axial direction of the turbo blade And a coupling that is fitted and fixed to the rotary shaft through a central through hole. The coupling is fitted and fixed to the rotary shaft, and the one end side of the turbo blade A turbo-type rotating device characterized in that a turbo wing and a rotating shaft are connected by inserting a ring into an annular portion of the coupling.   The turbo rotating device according to claim 1, wherein the insertion of the turbo blade into the coupling is an interference fit.   The outer peripheral surface of the turbo blade is formed in a tapered shape, and the inner peripheral surface in the annular portion of the coupling is formed in a conical shape corresponding to the tapered shape, and the outer peripheral surface of the turbo blade and the conical inner peripheral surface of the coupling are joined. 2. The turbo rotating device according to claim 1, wherein the turbo blade and the rotating shaft are coupled together.   4. The turbo rotating device according to claim 1, wherein the coupling is made of a material having a linear expansion coefficient that is the same as or similar to that of the rotating shaft.   4. The turbo rotating device according to claim 1, wherein the coupling is made of a material having a linear expansion coefficient that is the same as or similar to that of the partition board.   A turbo blade is attached to a rotary shaft that is driven to rotate by a rotational drive source, a turbo mechanism that performs a pump function by the rotation of the turbo blade and a partition that separates the rotary drive source from the turbo mechanism are provided. A turbo-type rotating device in which the rotating shaft passes through a portion, and includes a coupling attached to the rotating shaft having an annular portion that engages with an outer peripheral surface on one axial end side of the turbo blade. 2. The turbo rotating device according to claim 1, wherein the turbo rotating device is disposed at a position of the partition wall and a seal mechanism is formed between the outer peripheral surface of the coupling and the partition wall.   The turbo rotating device according to claim 6, wherein a labyrinth structure is provided for a sealing function between the coupling and the partition wall.

Images