JP2006233816A - Manufacturing method of screw rotor - Google Patents

Manufacturing method of screw rotor Download PDF

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Publication number
JP2006233816A
JP2006233816A JP2005047620A JP2005047620A JP2006233816A JP 2006233816 A JP2006233816 A JP 2006233816A JP 2005047620 A JP2005047620 A JP 2005047620A JP 2005047620 A JP2005047620 A JP 2005047620A JP 2006233816 A JP2006233816 A JP 2006233816A
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Prior art keywords
screw rotor
shaped
pipe
mold
female
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JP2005047620A
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JP4504836B2 (en
Inventor
Masakazu Aoki
Tatsutomo Nishihara
Kouji Wada
皇二 和田
達知 西原
優和 青木
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Hitachi Industrial Equipment Systems Co Ltd
株式会社日立産機システム
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Abstract

Provided is a screw rotor manufacturing method capable of easily plastically processing even a high-strength pipe-shaped material and improving productivity.
In a method of manufacturing a screw rotor 1 having a helical tooth portion 2 and a hollow portion 3, a female die 6 having a torsion rotating mechanism 9 in which the rotation angle around the axis gradually increases in the axial direction is used. The pipe-shaped material 5 is shortened by applying pressure to the inside of the pipe-shaped material 5 disposed in the female mold 6 and the axially contracted side, and the pipe-shaped material 5 is twisted by the torsional rotation mechanism 9 of the female mold 6. The helical tooth portion 2 is formed while being deformed.
[Selection] Figure 5

Description

  The present invention relates to a screw rotor used in a screw fluid machine, and more particularly, to a method for manufacturing a hollow screw rotor having spiral teeth.

  A screw compressor, which is an example of a screw fluid machine, includes a male rotor and a female rotor that rotate in parallel so that their rotational axes are parallel and mesh with helical teeth, and a casing that houses these male and female rotors. The working chamber for compressing the fluid to be compressed is formed by the tooth grooves of the male rotor and the female rotor and the inner wall of the casing. Since the male rotor and the female rotor (hereinafter collectively referred to as a screw rotor) and the like increase in temperature due to adiabatic compression of the fluid to be compressed and thermally expand, the clearance between the screw rotors and the clearance between the screw rotor and the casing Is increased with a margin of thermal expansion to prevent contact and damage of each member during operation. At this time, the rising temperature of the screw rotor and the accompanying thermal expansion are not uniform or constant, and the gap is increased in consideration of the maximum thermal expansion, which causes the performance of the compressor to deteriorate. In addition, when the screw rotor has a solid structure, since the moment of inertia is large, a large starting torque is required, which makes starting control difficult, and for example, rotational speed control for the purpose of energy saving becomes difficult.

  Therefore, in order to cope with this, a screw rotor having a hollow structure capable of circulating a cooling medium in the hollow portion has been proposed. As an example of a screw rotor having a hollow structure, conventionally, a hollow rotor body in which a meshing portion and a bottom portion are integrally formed with a plate material, and a hollow rotor that is fitted on the inner peripheral side of the bottom portion of the rotor body and joined by, for example, spot welding or the like. The structure provided with the rotor shaft is disclosed (for example, refer patent document 1). The rotor body manufacturing method in this prior art uses a split mold having the outer peripheral shape of the rotor body, and a pipe-shaped material having an appropriate pressability (ductility) is arranged inside the split mold. The pipe-shaped material is pressurized with a high-pressure fluid from the inside, and thereby the pipe-shaped material is expanded and pressed against the mold to form the meshing portion and the bottom portion.

JP-A-8-284856

However, the following problems exist in the above-described conventional technology.
That is, in the above rotor body manufacturing method, the pipe-shaped material is pressed and expanded from the inside and pressed against the mold, and the valley of the pipe-shaped material hardly extends, and the thickness of the meshing portion Molding is performed so that the dimensions gradually decrease from the tooth base toward the tooth tip. Such a plastic deformation method for a pipe-shaped material cannot be easily performed unless a plastic material having a relatively low strength is used. In other words, a high-strength pipe-shaped material required for a screw fluid machine or the like is plastically deformed. It was difficult.

  An object of the present invention is to provide a method of manufacturing a screw rotor that can be easily plastically processed even with a high-strength pipe-shaped material and can improve productivity.

  (1) In order to achieve the above object, the present invention has a torsional rotation mechanism in which the rotation angle about the axis gradually increases in the axial direction in the method of manufacturing a hollow screw rotor having spiral teeth. Using a female mold, pressure is applied to the inside of the pipe-shaped material arranged in the female mold and to the axially shortened side, so that the pipe-shaped material is contracted and the pipe-shaped material is reduced by the female torsion rotating mechanism. The helical teeth are formed while twisting and deforming.

  In the present invention, the screw rotor is manufactured using a female die having a torsional rotation mechanism in which the rotation angle around the axis gradually increases in the axial direction. Specifically, when pressure is applied to the axially shortened side of the pipe-shaped material placed in the female mold, the pipe-shaped material is contracted (buckled), and the component force of the axially contracted side pressure acts as a rotational force. The female torsion rotating mechanism operates (for example, by a rotational force applied to the pipe-shaped material), and the pipe-shaped material is torsionally deformed by the torsion rotating mechanism. At the same time, when a compressed fluid (such as high-temperature or high-pressure water) is circulated inside the pipe-shaped material, the pipe-shaped material is pressed against the female mold by the internal pressure to form a helical tooth. As described above, in the present embodiment, by using a female die having a torsion rotating mechanism, a helical tooth can be formed while shortening and twisting the pipe-shaped material. As a result, plastic processing can be performed so that the thickness dimension of the pipe-shaped material is substantially uniform, and even a high-strength pipe-shaped material can be easily plastic-processed. In addition, since plastic processing can be performed into a near net shape, the number of processing steps such as cutting can be reduced, and the cost can be reduced. Therefore, the productivity of the screw rotor can be improved.

  (2) In order to achieve the above object, the present invention also provides a method for producing a hollow screw rotor having spiral teeth, wherein a torsion rotating mechanism in which the rotation angle about the axis gradually increases in the axial direction. The pipe-shaped material is shortened by applying pressure to the inside and the axially shortened side of the pipe-shaped material disposed in the female mold, and torsional rotation mechanism of the female-type Thus, the helical teeth are formed while twisting and deforming the pipe-shaped material.

  (3) In the above (1) or (2), preferably, the female die is stacked in the axial direction in the die container and in the die container, and has the same shape as the radial cross section of the teeth of the screw rotor. A plurality of mold plates having grooves, and the female torsional rotation mechanism includes rotation angle limiting means for limiting the rotation angles of the plurality of template plates with respect to the mold container.

  (4) In the above (3), preferably, the rotation angle limiting means is configured such that the protrusion extending in the axial direction on the inner peripheral side of the mold container and the protrusion of the mold container are loosely fitted. It is comprised with the groove part each formed in the outer peripheral side of the said some template.

  (5) In the above (3), preferably, the rotation angle limiting means is configured such that the protrusions provided on the outer peripheral sides of the plurality of template plates and the protrusions of the plurality of template plates are loosely fitted. And a groove formed on the inner peripheral side of the mold container.

  According to the present invention, since plastic processing can be performed so that the thickness dimension of the pipe-shaped material is substantially uniform, even a high-strength pipe-shaped material can be easily plastic-processed. Therefore, the productivity of the screw rotor can be improved.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is an axial sectional view showing the structure of a screw rotor manufactured by the screw rotor manufacturing method of the present embodiment.

  In FIG. 1, a screw rotor 1 is a male rotor used in a screw compressor or the like, a helical tooth portion 2 formed on the outer peripheral side, a hollow portion 3 having a shape substantially similar to the tooth portion 2, Cylindrical shaft portions 4A and 4B formed on both ends in the axial direction of the tooth portion 2 (upper and lower sides in FIG. 1). A substantially cylindrical shaft member (not shown) is joined to the outside in the axial direction of the shaft portions 4A and 4B.

  For example, when the cooling medium is circulated through the hollow portion 2, the screw rotor 1 having such a hollow structure moves along the spiral hollow portion 2 as the screw rotor 1 rotates, thereby efficiently cooling. Therefore, the thermal expansion of the screw rotor 1 is reduced. As a result, the performance and reliability of the screw compressor are improved. Further, since the weight is reduced as compared with a solid structure screw rotor, the moment of inertia is reduced, the starting torque is reduced, the starting control is improved, and the responsiveness of the rotational speed control is also improved.

  Next, the manufacturing method of the screw rotor according to the present embodiment will be described. FIG. 2 is an axial sectional view showing the overall structure of the female die used for manufacturing the screw rotor 1, and shows a state before the pipe-shaped material is plastically processed. FIG. 3 shows a template of the female die. FIG. 4 is a perspective view showing a detailed structure, and FIG. 4 is a plan view as seen from an arrow IV direction in FIG. FIG. 5 is an axial sectional view showing the overall structure of the female mold, showing a state after plastic processing of the pipe-shaped material, and FIG. 6 is a plan view as seen from the direction of arrow VI in FIG. is there. 4 and 6, for convenience, the pipe-shaped material is not shown, and three of the template plates are representatively shown.

  2 to 6, for example, a female mold 6 for plastic processing of a pipe-shaped material 5 made of stainless steel has a cylindrical mold container 7 and an axial direction in the mold container 7 (in FIGS. 2 and 5). And a plurality of disk-shaped template plates 8 stacked in the vertical direction, and in the axial direction (in this embodiment, toward the lower side in FIGS. 2 and 5) There is provided a torsional rotation mechanism 9 in which the rotation angle gradually increases.

  In the mold container 7, for example, a cylindrical side wall 7a and a disk-shaped bottom plate 7b are integrally formed, and a circular opening 10 through which the pipe-shaped material 5 can be inserted is formed at the center of the bottom plate 7b. ing. Further, a projection 11 having the same radial cross-sectional shape and extending in the axial direction is formed on the inner peripheral side of the side wall 7 a of the mold container 7.

  A hole groove 12 having the same shape as the outer peripheral side shape of the radial section of the tooth portion 2 of the screw rotor 1 is formed in the center portion of the template 8. Then, by shifting the rotational positions of the plurality of template plates 8 laminated in the axial direction, the overall shape of the plurality of hole grooves 12 is made substantially the same as the outer peripheral side shape of the tooth portion 2 of the screw rotor 1. Is possible. Further, the thickness of the template 8 is a thickness dimension designed so that the overall shape of the plurality of hole grooves 12 described above is smooth and the strength of the template 8 itself can be sufficiently secured. The center of the hole groove 12 of the plurality of mold plates 8 and the center of the opening 10 of the bottom plate 7b of the mold container 7 are disposed on the same axis.

  Further, on the outer peripheral side of the plurality of template 8, a groove portion 13 is formed in which the circumferential groove width dimension gradually increases in the axial direction. Specifically, as shown in FIG. 4, the groove width dimension of the groove portion 13A of the template 8 <the groove width dimension of the groove portion 13B of the lower mold plate 8 <the groove width of the groove portion 13C of the lower mold plate 8 Dimensions ... And the protrusion part 11 of the type | mold container 7 is loosely fitted by the groove part 13 of all the template 8, and according to the groove width dimension of the groove part 13, the rotation angle of the template 8 is each restrict | limited. Yes. Thus, the torsion rotating mechanism 9 is provided in which the rotational angle around the axis of the template 8 gradually increases toward the axial direction.

  Then, as shown in FIG. 4, the circumferential side wall (on the left side in FIG. 4) of the groove 13 (only 13A, 13B and 13C are shown in FIG. In a state where the side wall in the circumferential direction of the portion 11 (the counterclockwise side in FIG. 4) is in contact, the hole grooves 12 (only 12A, 12B, and 12C are shown in FIG. 4) of all the mold plates 8 are aligned. ing. Further, as shown in FIG. 5, the side wall of the groove portion 13 (only 13A, 13B, 13C is shown in FIG. 5) of all the mold plates 8 (the clockwise side in FIG. 5) and the protrusion of the mold container 7 In a state in which the side wall on the other side in the circumferential direction of the portion 11 (clockwise side in FIG. 5) is in contact, the plurality of template plates 8 are rotated at a rotation angle corresponding to the groove width dimension of the groove portion 13. The overall shape of the hole groove 12 (only 12A, 12B, and 12C are shown in FIG. 5) is substantially the same as the outer peripheral side shape of the tooth portion 2 of the screw rotor 1.

  In the above description, the protrusions 11 of the mold container 7 and the grooves 13 of the plurality of mold plates 8 constitute rotation angle limiting means for limiting the rotation angles of the plurality of template plates with respect to the mold container described in the claims. .

  And the manufacturing method of the screw rotor 1 by this embodiment is the state which aligned the hole groove | channel 12 of all the template 8 laminated | stacked in the type | mold container 7, as shown in above-mentioned FIG.2 and FIG.4 first, For example, a stainless steel pipe-shaped material 5 is inserted into the hole groove 12 of the mold plate 8 and the opening 10 of the mold container 7. Next, one end (the lower side in FIG. 2) of the pipe-shaped material 5 is fixed, and the other end (the upper side in FIG. 2) of the pipe-shaped material 5 is axially shortened (the figure). When pressure is applied to the lower part of 2, the pipe-shaped material 5 contracts (buckles), and the component of the axial contraction side pressure acts as a rotational force to operate the torsional rotation mechanism 9 of the female mold 6 ( Specifically, the pipe-shaped material 5 is torsionally deformed by this torsional rotation mechanism 9, which rotates from the side to which the axially reduced pressure is applied to the angle at which the template 8 can rotate. At the same time, when a compressed fluid (high pressure, high temperature water, etc.) is circulated inside the pipe-shaped material 5, the pipe-shaped material 5 is pressed against the hole groove 12 of the template 8 by the internal pressure, and the helical teeth 2 are moved. Molding is performed (see FIGS. 5 and 6).

  As described above, in the present embodiment, by using the female die 6 having the torsion rotating mechanism 9, the helical tooth portion 2 can be formed while the pipe-shaped material 5 is shortened and twisted. As a result, plastic processing can be performed so that the thickness dimension of the pipe-shaped material 5 is substantially uniform, and even a high-strength pipe-shaped material 5 made of stainless steel can be easily plastic-processed. In addition, since plastic processing can be performed into a near net shape, the number of processing steps such as cutting can be reduced, and the cost can be reduced. Therefore, the productivity of the screw rotor 1 can be improved.

  In the above-described embodiment, the case where pressure is applied to the inside of the pipe-shaped material 5 and the axially shortened side has been described as an example, but in addition to this, for example, the pipe-shaped material 5 (or the template 8) A rotational force may be applied. In this case, the same effect as described above can be obtained.

  Further, in the above-described embodiment, the rotation angle limiting means is provided on the inner peripheral side of the mold container 7, and has a projection 11 having the same radial cross-sectional shape and extending in the axial direction, and An example has been described in which the groove portion 13 is formed on the outer peripheral side of the plurality of template 8 so that the portion 11 is loosely fitted and the groove width dimension in the circumferential direction gradually increases toward the axial direction. However, it is not limited to this. That is, for example, the protrusion 11 ′ of the mold container 7 is provided so that the radial cross-sectional shape gradually decreases in the axial direction, and the groove portions 13 ′ of the plurality of mold plates 8 have the same groove width dimension in the circumferential direction. Each may be formed as described above. Even in such a case, the above-described torsional rotation mechanism can be provided, and the same effect as in the above-described embodiment can be obtained. Further, for example, by providing protrusions on the outer peripheral sides of the plurality of mold plates 8 and forming grooves on the inner peripheral side of the mold container 7 so that these protrusions are loosely fitted, the twist rotation mechanism is provided. Also good. Even in such a case, the same effect as the above-described embodiment can be obtained.

  In the above description, the male rotor of the screw compressor has been described as an example of the screw rotor. However, the present invention is not limited to this, and is applicable to, for example, a female rotor of a screw compressor, a rotor of a screw pump, a torsion rotor of a roots blower, and a worm gear. Needless to say.

It is an axial direction sectional view showing the structure of the screw rotor manufactured by one embodiment of the manufacturing method of the screw rotor of the present invention. It is an axial sectional view showing the whole female mold structure in one embodiment of the manufacturing method of the screw rotor of the present invention, and represents the state before plastic processing of a pipe-shaped material. It is a perspective view showing the detailed structure of the template which comprises the female type | mold in one Embodiment of the manufacturing method of the screw rotor of this invention. It is the arrow view top view of the female type seen from the arrow IV direction in FIG. It is an axial direction sectional view showing the whole female mold structure in one embodiment of the manufacturing method of the screw rotor of the present invention, and represents the state after plastic processing of a pipe-shaped material. FIG. 6 is a plan view of a female mold as seen from the direction of arrow VI in FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Screw rotor 2 Tooth part 3 Hollow part 5 Pipe-shaped raw material 6 Female type | mold 7 Type | mold container 8 Template 9 Torsion rotation mechanism 11 Protrusion part 12 Groove | groove (rotation angle limiting means)
13 Groove (Rotation angle limiting means)

Claims (5)

  1. In a method for producing a hollow screw rotor having helical teeth,
    By using a female mold having a torsional rotation mechanism in which the rotation angle around the axis gradually increases in the axial direction, by applying pressure to the inside of the pipe-shaped material arranged in the female mold and the axially shortened side, A method of manufacturing a screw rotor, comprising: shortening a pipe-shaped material and forming the helical teeth while twisting and deforming the pipe-shaped material by the female torsion rotating mechanism.
  2. In a method for producing a hollow screw rotor having helical teeth,
    Using a female mold having a torsional rotation mechanism in which the rotation angle around the axis gradually increases in the axial direction, pressure is applied to the inside of the pipe-shaped material arranged in this female mold and the axially shortened side, and rotational force is applied. A method of manufacturing a screw rotor, wherein the helical teeth are formed while the pipe-shaped material is shortened and the pipe-shaped material is torsionally deformed by the female torsion rotating mechanism.
  3.   3. The screw rotor manufacturing method according to claim 1, wherein the female die is laminated in a mold container and an axial direction in the mold container, and has a hole groove having the same shape as a radial cross section of the tooth of the screw rotor. A screw rotor, wherein the female torsional rotation mechanism is provided with rotation angle limiting means for limiting the rotation angles of the plurality of mold plates with respect to the mold container. Manufacturing method.
  4.   4. The screw rotor manufacturing method according to claim 3, wherein the rotation angle limiting means is configured such that the protrusion extending in the axial direction on the inner peripheral side of the mold container and the protrusion of the mold container are loosely fitted. A method for manufacturing a screw rotor, comprising: groove portions formed on the outer peripheral sides of the plurality of template plates.
  5.   The screw rotor manufacturing method according to claim 3, wherein the rotation angle limiting means is configured such that the protrusions provided on the outer peripheral sides of the plurality of template plates and the protrusions of the plurality of template plates are loosely fitted. A method for manufacturing a screw rotor, comprising: a groove formed on an inner peripheral side of the mold container.
JP2005047620A 2005-02-23 2005-02-23 Screw rotor manufacturing method Expired - Fee Related JP4504836B2 (en)

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JP2005047620A JP4504836B2 (en) 2005-02-23 2005-02-23 Screw rotor manufacturing method

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JP4504836B2 JP4504836B2 (en) 2010-07-14

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015138557A1 (en) * 2014-03-12 2015-09-17 Eaton Corporation Methods for making a low inertia laminated rotor
US9932983B2 (en) 2013-03-15 2018-04-03 Eaton Intelligent Power Limited Low inertia laminated rotor
US10208656B2 (en) 2012-11-20 2019-02-19 Eaton Intelligent Power Limited Composite supercharger rotors and methods of construction thereof

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS49110810U (en) * 1973-01-19 1974-09-21
JPS5770985A (en) * 1980-10-22 1982-05-01 Hitachi Ltd Screw rotor and its manufacturing method
JPS6263190A (en) * 1985-09-13 1987-03-19 Jidosha Kiki Co Ltd Production of screw rotor
JPH02235525A (en) * 1989-03-06 1990-09-18 Honda Motor Co Ltd Manufacture of screw rotor
JPH05195701A (en) * 1991-10-17 1993-08-03 Ebara Corp Screw rotor and its manufacturing method
JPH06101671A (en) * 1992-09-21 1994-04-12 Kobe Steel Ltd Screw rotor
JPH08284856A (en) * 1995-04-07 1996-10-29 Tochigi Fuji Ind Co Ltd Rotor and formation thereof

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS49110810U (en) * 1973-01-19 1974-09-21
JPS5770985A (en) * 1980-10-22 1982-05-01 Hitachi Ltd Screw rotor and its manufacturing method
JPS6263190A (en) * 1985-09-13 1987-03-19 Jidosha Kiki Co Ltd Production of screw rotor
JPH02235525A (en) * 1989-03-06 1990-09-18 Honda Motor Co Ltd Manufacture of screw rotor
JPH05195701A (en) * 1991-10-17 1993-08-03 Ebara Corp Screw rotor and its manufacturing method
JPH06101671A (en) * 1992-09-21 1994-04-12 Kobe Steel Ltd Screw rotor
JPH08284856A (en) * 1995-04-07 1996-10-29 Tochigi Fuji Ind Co Ltd Rotor and formation thereof

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10208656B2 (en) 2012-11-20 2019-02-19 Eaton Intelligent Power Limited Composite supercharger rotors and methods of construction thereof
US9932983B2 (en) 2013-03-15 2018-04-03 Eaton Intelligent Power Limited Low inertia laminated rotor
WO2015138557A1 (en) * 2014-03-12 2015-09-17 Eaton Corporation Methods for making a low inertia laminated rotor

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