JPH07103855B2 - Vane compressor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vane compressor, and more particularly to a vane compressor having a rotor composed of an aluminum alloy rotor and a steel shaft.

[0002]

2. Description of the Related Art As is well known for compressors, turbo type (blade rotation type) such as axial flow type, centrifugal type, or rotary type
Although there are various types such as reciprocating type and positive displacement type, among these compressors, the vane type compressor (moving vane compressor) has a small size, high compression efficiency, and low vibration and noise. In addition, it has advantages such as small discharge pulsation, and has been a typical one of rotary compressors.

By the way, generally, in a rotor constituting a compressor, that is, a shaft and a rotor provided on the shaft, the both of them are conventionally coupled by a well-known means, that is, by shrink fitting, cooling fitting, press fitting, or the like. It is normal. However, it is not possible to expect more than a certain degree of bonding force by these conventional general means, and especially when the rotor is made of a metal having a large coefficient of thermal expansion such as an aluminum alloy, it may be satisfied by shrink fitting. There is a problem that the bond strength to be obtained cannot be obtained. Therefore, the following proposals have already been made to solve such problems.

For example, Japanese Unexamined Patent Publication No. 63-134134 discloses a method (structure) shown in FIGS. 10 and 11 for connecting a steel shaft and a cylindrical member made of an aluminum alloy. This is because four stages of fitting portions 2, 3, 4, 5 having different outer diameters are sequentially formed on the steel shaft 1, and these four stages of fitting portions 2 to 5 are formed into the inner diameter of the cylindrical member 6 made of aluminum alloy. Different fitting portions 7, 8, 9 and 10 respectively, and the inner fitting portions 3 and 4 of the steel shaft 1 are formed with serrations 3a and 4a, while the outer fitting portion 2 is formed. , 5 are smooth surfaces. Then, the inner two-stage fitting portions 3 and 4 of the steel shaft 1 are coupled with the cylindrical member 6 in a biting interference fitting state, and the outer two-stage fitting portions 2 and 5 are coupled by press fitting. It is a thing.

Further, Japanese Patent Laid-Open No. 63-158306 discloses a shaft 11 and a cylindrical member 1 as shown in FIGS.
When connecting with 4, the fitting parts 12, 13, 15, 16 are formed on the shaft 11 and the cylindrical member 14, respectively, and one fitting part 12, 15 is fitted to the other fitting part 13, 16. Eccentricity and both fitting portions 12, 15, 13, 16 are joined by interference fitting.

Further, although not shown, a recess is formed in the joining surface of the material to be joined, and the other member to be joined to the material to be joined is deformed under pressure to part of the member to be joined. Method of joining by making plastic flow into the concave part of
(JP-A-57-146444 and JP-A-59-14)
No. 1341) and the like are provided.

[0007]

However, each of the above-mentioned coupling means also has the following disadvantages. That is, in the coupling structure shown in FIGS. 10 and 11, although the serrations 3a and 4a certainly provide a strong coupling force, the fitting portions are formed in four steps, and the serrations 3a and 4a are formed in two of the steps. It takes a lot of time to form 4a, and the serrations 3a and 4a and the cylindrical member 6 are formed.
There is a possibility that a gap may be formed between the fitting portions 8 and 9, and if such a gap occurs, there arises a problem that stress concentration is caused in the serration portion.

Further, according to the method shown in FIGS. 12 and 13, it is possible to surely realize stronger coupling than the usual simple interference fit, and it is applied to the case where a large torque is applied. Although it is possible to form the fitting portions 12 and 15 which are eccentric to both the shaft 11 and the cylindrical member 14 in the interference fitting coupling which originally requires strict dimension setting, it is a very costly operation. Not only is it economical, but residual stress that is unevenly generated in both members 11 and 14 after joining causes anxiety in terms of durability and the like.

Further, in the method of plastically flowing one of the members into the concave portion by the pressure deformation, when the plastic deformation due to the pressure is surely achieved, a strong joint can be expected, but when the plastic flow is generated, The fluidity of the member is low because only a pressing force in the uniaxial direction is applied between the two members, so an extremely large pressure force is required to generate the plastic flow, and the part where the plastic flow occurs enters. However, there is a problem that the shape of the recess is limited. That is, since a pressing force in only one axial direction is applied between the two members, the stress generated by the pressing force also becomes unidirectional, and the flow of the members occurs only in a fixed direction. Therefore, it is difficult to completely fill the flow part with a complicatedly shaped recess (groove), and there is a risk that voids will be created, and this void causes stress concentration. The problem is that the recesses need to be specially processed in order to obtain the desired bonding strength such as rotation resistance and pullout resistance, in addition to being extremely simple materials into which metal can easily enter. Will occur. Further, for example, when the rotor 17 and the shaft 18 are coupled as shown in FIG. 14, when the thickness (axial dimension) T of the coupling portion of the rotor 17 is small, a satisfactory plastic flow is generated even by the above-mentioned conventional method. However, when the thickness T of the rotor 17 is large as shown in FIG. 15, it is difficult to transmit sufficient stress to cause plastic flow to the inside, and thus sufficient coupling strength is achieved. However, there is a problem that it is difficult to connect the rotor and the shaft in the vane type compressor having a relatively large axial dimension as described above.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vane type compression having a rotor composed of a rotor made of an aluminum alloy and a shaft made of steel. (EN) Provided is a vane compressor capable of realizing an extremely strong coupling between the rotor and the shaft by a simple means.

[0011]

According to the present invention, there is provided a rotor made of an aluminum alloy having one or more movable blades on its outer peripheral portion, and a steel shaft fitted to the central portion of the shaft of the rotor. A rotor composed of and is provided eccentrically with respect to the casing cylinder, and compresses gas by a volume change corresponding to the eccentric separation of the working chamber formed by the movable blades and the casing cylinder inner peripheral surface and the rotor outer peripheral surface. In the vane type compressor configured to perform, after inserting the rotor into a fitting hole formed in the shaft center portion of the rotor, the thickness of the rotor near the coupling portion of the rotor It is characterized in that it is coupled with the shaft by applying a rotational force in the direction around the axis while pressing in the direction, and causing plastic flow in the vicinity of the fitting hole of the rotor by these pressing force and rotational force. .

[0012]

By applying a rotational force to the rotor while pressing the aluminum alloy rotor, a composite stress is generated in the rotor by the pressing force and the rotational force. As a result, sufficient plastic flow can be generated in the rotor joint with an extremely small load, and thus extremely good joining work and excellent joining force can be realized, and the axial dimension It also ensures that a large rotor can be connected to the shaft.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a vane type compressor according to the present invention. This vane type compressor 20 is a rotating body made of an aluminum alloy having a plurality of movable vanes (vanes) 22, 22, ... A rotor 60 including a child 30 and a steel shaft 40 provided at a central portion of the rotor 30 is provided eccentrically with respect to the casing cylinder 21, and when the rotor 60 rotates, Movable wings 22,2
, And the working chambers 23, 23, ... Formed by the casing cylinder inner peripheral surface 21a and the rotor outer peripheral surface 30a.
The gas is compressed by the volume change corresponding to the eccentric separation.

FIG. 2 shows the rotor 60. Grooves 31, 31, ... Are formed on the rotor 30 from the outer peripheral surface 30a of the rotor 30 toward the center of the shaft. , 22, ... Are provided so as to be slidable in the radial direction. That is, while the rotor 60 is rotating, as shown in FIG. 1, the movable blades 22, 22, ... Are projected to the outside of the rotor 30 by the centrifugal force or the biasing force of a spring or the like, and the tips of the movable blades 22. The portion 22a abuts and slides on the inner peripheral surface 21a of the casing cylinder 21 and constitutes the working chambers 23, 23, .... In this case, the rotor 30 is made of a high silicon aluminum alloy and the shaft 40 is made of manganese steel, and both are joined as follows.

In FIG. 3, reference numeral 50 designates the rotor 30.
Is a jig used to connect the rotor 30 with the shaft 40.
Is formed with a set cross-section 51 having a circular cross-section for holding it horizontally such that its axial direction is oriented in the vertical direction. Set hole 51
The inner peripheral surface 51a of the rotor is in full contact with the outer peripheral surface 30a of the rotor 30 (excluding the groove 31) to restrain the rotor 30 in the radial direction. The rotor 30 has a bottom surface 51b of the set hole 51.
It is set in the state of being in contact with. A shaft insertion hole 52 for inserting the protruding end of the shaft 40 inserted into the fitting hole 32 of the rotor 30 is fitted in the central portion of the bottom surface 51b of the set hole 51.
It is formed coaxially with the dowel 32 . This shaft insertion hole 52
Is closed by the movable bottom portion 53, and the depth (depth) can be freely set. Further, although not shown, the jig 50 has fixing means for firmly restraining the shaft 40 both in the axial direction and in the axial rotation direction, and The entire portion for restraining 40 is configured to be rotatable around the axis together with the rotor 30.

The inner diameter of the center portion of the fitting hole 32 of the rotor 30 in the lengthwise direction is made larger than the inner diameters of both ends to form a recess 33. Inner diameters d ₁ and d ₂ at both ends of the fitting hole 32
Are set to be slightly larger (0.01 to 0.03 mm in the embodiment) with respect to the outer diameters d ₃ and d _{4 of} the shaft 40 corresponding thereto.
Thus , a clearance is formed between the rod-shaped member and the rod-shaped member.

Reference numeral 71 presses the rotor 30 in its thickness direction, that is, in the axial direction of the fitting hole 32, and
It is an operator of a pressure twisting device 70 (not shown in its entirety) for imparting rotation about an axis to the rotor 30. The operator 71 has a shaft 4 that is inserted into the fitting hole 32 as shown in the drawing.
An escape hole 72 for crossing 0 is formed at the center of the shaft.

In connecting the rotor 30 and the shaft 40, in this embodiment, the connecting portion of the rotor 30, that is, the periphery of the fitting hole 32 is preliminarily 100 ° C. to 300 ° C., preferably 150 ° C. Heat to a temperature range of 250 ° C. The temperature range here is a temperature range close to the warm forming temperature of the aluminum alloy forming the rotor 30 in this embodiment. The heating temperature of the rotor 30 made of aluminum alloy is preferably in the vicinity of the warm forming temperature of the aluminum alloy constituting the rotor 30 as described above,
It is not always necessary to use the warm forming temperature. That is, it is possible to see a decrease in deformation resistance due to a temperature rise even if the heating temperature does not reach the warm forming temperature range as in this embodiment.

The rotor 30 whose joint is heated as described above
3 is mounted in the setting hole 51 of the jig 50 as shown in FIG. 3 , the shaft 40 is then inserted into the fitting hole 32 of the rotor 30. At this time, since the clearance is provided between the fitting hole 32 and the shaft 40, the shaft 40 can be smoothly inserted. After the shaft 40 is inserted into the fitting hole 32, the movable bottom portion 53 is moved, and the rotor 30 is adjusted and fixed so as to correspond to a predetermined position in the length direction of the shaft 40.
Of course, the fixed position of the movable bottom portion 53 may be set in advance before inserting the shaft 40. Further, the fixing means of the shaft 40 can be configured in the pressure twisting device 70.

When the shaft 40 is set on the rotor 30 as described above, the operator 71 of the pressure twisting device 70 is located near the center of the upper surface 30b of the rotor 30, that is, the opening of the fitting hole 32, as shown in the figure. Apply in the vicinity. And after this,
The pressing and twisting device 70 is driven to pressurize the operator 71 strongly downward, and twists around the axis of the fitting hole 32, that is, around the axis 40. That is, at this time, both the pressing force and the twisting force (rotational force) are applied to the rotor 30. Since the outer peripheral surface 30a of the rotor 30 is constrained by the inner peripheral surface 51a of the jig 50,
The axial direction (thickness direction) pressing force causes a plastic flow toward the center of the shaft, and the center of the rotor 30 near the center, that is, the fitting hole 32.
The diameter of the portion in the vicinity of is reduced, and the shaft 40 is strongly crimped.

Here, the reason why the vicinity of the central portion of the rotor 30 is reduced to the shaft 40 side by the pressing operation as described above is theorized from the "Tresca yielding condition" in the theory of plasticity. That is, according to the yield condition of Tresca, when the deformation resistance of a material is Kf, the maximum principal stress generated in the material when an external force is applied to the material is σ ₁ , and the minimum principal stress σ ₃ is When the condition shown, (σ ₁ −σ ₃ ) >> Kf, is satisfied, the material deforms in the direction of the minimum principal stress σ ₃ . Therefore, in the above case, the operator 7
It can be understood that by pressing (compressing) the vicinity of the central portion of the rotor 30 with No. 1, the vicinity of the fitting hole 32 of the rotor 30 plastically flows toward the central portion of the shaft.

Further, in this case, since a twisting force is applied in addition to the above pressing force, a composite stress is generated inside the rotor 30, which is a combination of the stress due to the pressing force and the stress due to the torsional force. As a result, the plastic flow becomes extremely easy, that is, a sufficient plastic flow can be generated with a small load. Moreover, in this embodiment, since the joint portion of the rotor 30 which applies the pressing / rotating force is heated to the warm forming temperature as described above, the deformation resistance of the joint portion is at room temperature (cold forming temperature). ) It is significantly reduced over time, and the plastic fluidity is exceptionally excellent. However, the work of connecting the rotor 30 and the shaft 40 does not necessarily have to heat the rotor 30 as described above, and can be performed at room temperature. Even in that case, the composite stress generated by the pressing force and the rotating force can easily cause the plastic flow of the joint portion of the rotor 30, so that the rotor 3 made of aluminum alloy is used.
0 and the steel shaft 40 can be firmly connected.

As described above, if the rotor 30 and the shaft 40 are connected by the above means, the vane type compressor 2 according to the present invention.
0, or the rotor 30 as shown in FIG.
Even if the axial dimension T is large, it is possible to easily cause plastic flow over the entire joint portion, and it is possible to easily obtain sufficient joint strength. Further, since the rotor 30 made of an aluminum alloy has a large coefficient of thermal expansion, it has conventionally been difficult to be joined by shrink fitting or the like. However, in the present invention, it is rather good plastic working provided by the aluminum alloy. It can be said that it is an extremely effective coupling means that positively utilizes sex.

In carrying out the above-mentioned connection, as shown in FIG. 4 or 5, the ridge 42 is formed on the connecting portion of the shaft 40.
Alternatively, it is of course possible to arbitrarily form the serration portion by the knurling 43 or the like to enhance the binding force. By the way, FIG. 6 shows the torsional torque when the present invention is applied to both the case where the knurl 43 as shown in FIG. 5 is formed at the joint portion of the shaft 40 and the case where the knurl is not formed and the surface is smooth. It is a comparison of resistance. The horizontal axis is the diameter of the shaft 40. In this figure, for example, when the diameter of the shaft 40 is 60 mm, it can be seen that even without the knurling, the resistance to the torque of about 200 kg · m is obtained and an extremely high coupling force is obtained. When 43 is formed, the resistance shows a value of 300 Kg · m or more, and the coupling force against torsion torque is 50 compared to that without knurls.
You can see that it has improved by more than%.

FIG. 7 shows an example in which a concave groove 44 is formed in the shaft 40. In this case, the concave groove 44 is formed in a spiral shape as shown. The combining operation is similar to that described above. When the recessed groove 44 is formed in such a shape, when the rotor 30 and the shaft 40 are coupled, it is possible to exhibit an excellent low effect on both the torsion torque and the pulling torque. According to the example, it is possible to easily and sufficiently fill the concave groove 44 having such a shape with the fluid metal. Further, particularly in the case of this example, when the rotor 30 is rotated while being pressed, the rotor 30 is rotated in the same direction as the spiral forming direction of the concave groove 44 to further enhance the filling property of the fluid metal. You can Further, according to the above-mentioned coupling means, the plastic deformation of the coupling portion of the rotor 30 can be easily generated with a small load as described above, and therefore, it is impossible to achieve the conventional technique as shown in FIGS. 8 and 9, for example. It is possible to sufficiently fill the fluidized portion even in the recessed groove 44 and the like formed with the undercut, and it is possible to realize extremely high coupling.

Further, in particular, when a pressing / rotating force is applied to the rotor 30, if the entire circumference of the outer peripheral surface 30a of the rotor 30 is constrained and the vicinity of the center is uniformly pressed as in this embodiment, the rotor 3
Since the residual stress inside 0 is distributed uniformly and has high reliability against external force, this embodiment is correctly applied to the rotor 60 of the vane compressor 20 as described above, and is extremely effective.

[0027]

As described above, according to the present invention, in a vane type compressor having a rotor made of an aluminum alloy rotor and a steel shaft, the aluminum alloy rotor and the steel are provided. The coupling with the shaft is such that a pressing force and a rotating force are applied to the rotor, and the compound stress generated by these pressing and rotating forces causes a plastic flow in the vicinity of the fitting part of the rotor to couple with the shaft. Therefore, the plastic flow can be sufficiently generated with a small load, and thus the rotor and the shaft can be reliably and extremely firmly coupled by a simple means. Further, since it is possible to easily generate sufficient plastic flow in this way, it is possible to reliably realize the connection between the aluminum alloy rotor and the steel shaft, which have a large axial dimension, that is, a long fitting portion length. In addition, even when a recess or serration is provided on the steel shaft to allow the plastic flow part of the aluminum alloy rotor to flow in, the degree of freedom in setting the shape of these recesses increases, which further increases the bonding strength. It is possible to obtain excellent effects such as improvement of

[Brief description of drawings]

FIG. 1 is a side sectional view schematically showing a vane compressor according to the present invention.

FIG. 2 is a perspective view showing a rotor of a vane type compressor together with movable blades.

FIG. 3 is a longitudinal sectional view showing an aluminum alloy rotor and a steel shaft together with a jig.

FIG. 4 is a partial front view showing a steel shaft.

FIG. 5 is a partial front view showing a steel shaft.

FIG. 6 is a graph comparing the relationship between the diameter of the steel shaft and the resistance to the torsion torque with and without the knurls of the steel shaft.

FIG. 7 is a perspective view showing a modified example of the present embodiment, in which a part of an aluminum alloy rotor and a steel shaft is cut away.

FIG. 8 is a vertical sectional view showing a rotor and a shaft.

FIG. 9 is a vertical sectional view showing a rotor and a shaft.

FIG. 10 is a vertical cross-sectional view for explaining a conventional technique according to the present invention and showing a coupled state of a steel shaft and a cylindrical member.

FIG. 11 is an elevational view of a steel shaft for explaining the prior art according to the present invention.

FIG. 12 is a vertical cross-sectional view of a cylindrical member for explaining the conventional technique according to the present invention.

FIG. 13 is an elevational view of a shaft for explaining the related art according to the present invention.

FIG. 14 is a front view showing a rotor and a shaft joined to each other in a partial cross section, for explaining the conventional technique according to the present invention.

FIG. 15 is an elevational view for explaining the related art according to the present invention and showing a coupled rotor and shaft in a partial cross section.

[Explanation of symbols]

 20 vane type compressor 21 casing cylinder 21a inner peripheral surface 22 movable blade 23 working chamber 30 rotor 30a outer peripheral surface 32 fitting hole 40 shaft 60 rotor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shuji Yamane 4-3-1 Yashiki, Narashino-shi, Chiba Seiko Seiki Co., Ltd. (72) Inventor Takeshi Kobayashi 4-3-1 Yashiki, Narashino-shi, Chiba Seiko Seiki Co., Ltd. (56) Reference JP-A-3-52741 (JP, A)

Claims (1)

[Claims] 1. A casing cylinder is provided with a rotor composed of an aluminum alloy rotor having one or more movable blades on its outer peripheral portion and a steel shaft fitted in the shaft center portion of the rotor. Vane-type compression provided eccentrically with respect to each other and configured to compress gas by a volume change corresponding to eccentric separation of an action chamber formed by the movable blade, the inner peripheral surface of the casing cylinder, and the outer peripheral surface of the rotor. In the machine, the rotor rotates in the axial direction while inserting the shaft into a fitting hole formed in the center of the rotor, and pressing the vicinity of the coupling part of the rotor in the thickness direction of the rotor. The vane type compressor is characterized in that the vane type compressor is connected to the shaft by applying the rotational force of the above, and causing a plastic flow in the vicinity of the fitting hole of the rotor by the pressing force and the rotational force.