JPS6059816B2 - Rotating shaft of vehicle alternator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotating shaft of a vehicle alternator, and more particularly to a rotating shaft of a vehicle alternator suitable for being mounted on a diesel engine vehicle or a gasoline engine vehicle.

Generally, a vehicle AC generator directly connected to a vacuum pump is mounted on a diesel engine vehicle, and serves as a generator for charging and as a vacuum pump as a negative pressure generating device.

In this case, it is disclosed in Japanese Patent Application Laid-Open No. 53-1145,
As shown in FIG. 16, the rotating shaft 101 consists of an alternating current generator section IOIA and a vacuum pump drive section IOIB, which are integrally machined.

The vacuum pump is directly connected and driven by a vacuum pump drive unit 101B of the rotating shaft 101, and is connected to the engine crankshaft via a belt by a pulley fixed to the rotating shaft 101. On the other hand, vehicular alternators installed in gasoline engine vehicles do not require a vacuum pump.

Therefore, as shown in FIG. 17, the rotating shaft 102 is composed only of the alternating current generator section 102A. Note that a gasoline engine does not require a vacuum pump because it utilizes the negative pressure generated by the engine itself. Now, in the conventional technology as described above, the rotor of the vehicle alternator for a gasoline engine vehicle has a short rotating shaft 102;
On the other hand, the rotor of a vehicle alternator for a diesel engine vehicle has a long rotating shaft 101 consisting of an alternator section 101A and a vacuum pump drive section 101B, and two types of rotors are required.

As is well known, gasoline engine cars and diesel engine cars both have their own characteristics and are produced at the same time, so it is impossible for them to be integrated into one.

Therefore, the rotor and rotating shaft of a vehicle alternator are
It becomes necessary to produce two types. However, the rotor is an important component in the alternator, and requires many processing facilities for production (parts press-fitting, varnishing, drying, cutting finishing).
Requires. Furthermore, the rotating shaft 101 for diesel engine vehicles, which is long in the axial direction and has serrations at the tip, not only requires machining processes such as serration processing and induction hardening of the oil seal sliding part, but also suffers from bending of the shaft. etc. are likely to occur.

Therefore, it is not economical to provide equipment that can process two types of rotors and rotating shafts. Against this background, let's compare it to a gasoline engine car. Rotors and rotating shafts for diesel engine vehicles, which are produced in small quantities, are produced on separate processing lines and processing equipment.

Therefore, the productivity was inferior to that for gasoline engine vehicles, the yield of materials was poor, and the cost was high. SUMMARY OF THE INVENTION An object of the present invention is to provide a rotating shaft for a vehicle alternator that can share the rotating shaft for a gasoline engine vehicle as the rotating shaft of an alternator section for a diesel engine vehicle.
The present invention is characterized in that a shaft engaging recess is provided at the end of a first rotating shaft for a gasoline engine vehicle, and the engaging recess is made of a material having higher deformation resistance than the first rotating shaft. A second rotating shaft is formed by forming intermittent protrusions that protrude from the reference circle and extend in the longitudinal direction, and has a device drive part, and is plastically press-fitted into the second rotating shaft, and only the protrusions of the second rotating shaft and the vicinity thereof are connected to the first rotating shaft. The rotating shaft of the alternator for a vehicle is such that the first rotating shaft and the second rotating shaft are brought into close contact with each other and are coupled by the tensile force generated at the close contact portion and the shearing force of the projection of the second rotating shaft.

An embodiment of the present invention will be described based on the drawings. FIG. 1 shows a vehicle alternator directly connected to a vacuum pump mounted on a diesel engine vehicle to which the rotating shaft of the present invention is applied. The rotor 1 is mounted on the alternator section 7A of the rotating shaft 7, with magnetic poles 1a1 windings 1b1 slip rings 1
c, and constitutes the rotor magnetic pole.

A stator 2 is arranged around the outer periphery of the rotor 1, and is composed of an armature iron core 2a and a winding 2b, and outputs an alternating current output via a rectifier 8. Two brackets 3 and 4 are provided surrounding the rotor 1 and stator 2.

The bracket 3 is arranged on the pulley 5 side, and the bracket 4 is arranged on the side opposite to the pulley 5. Pulley 5 fixed to rotating shaft 7
is driven by a belt (not shown). Rotating shaft 7
A vacuum pump 6 is arranged on the vacuum pump driving section 7B.

This vacuum pump 6 is directly connected and driven by a rotating shaft 7, and is connected to the engine crankshaft via a pulley 5 via a belt. The vacuum pump 6 is a vane-shaped eccentric pump consisting of vanes 6a1 and a pump rotor 6b. The vacuum pump 6 is supplied with oil through the oil supply port 6c, sucks air through the suction port 6d, and discharges oil and air through the discharge port 6e. A brush 16 is disposed on the slip ring 1c of the rotor 1, and an oil seal 17 is disposed between the rotor 1 and the vacuum pump 6 on the rotating shaft 7.

The structure of the rotating shaft 7, which is a feature of the present invention, will be described in detail below.

The rotating shaft 7 is press-fitted into the rotor 1, extends long in the axial direction, and is composed of an alternating current generator section 7A and a vacuum pump drive section 7B having a serration section 10d. As shown in FIG. 3, the rotating shaft 7
and the shaft 10 that constitutes the vacuum pump drive section 7B, that is, the press-fit shaft 10 and the press-fit shaft 20. The rotating shaft of the alternator installed in the gasoline engine vehicle is composed of only the shaft 20 of the rotating shaft 7 of the diesel engine vehicle, which has an engagement hole 20a for the shaft 10 at the end opposite to the pulley. use.

In other words, as mentioned above, in the case of a gasoline engine car,
It uses the negative pressure generated in the engine itself, so there is no need for a vacuum pump. Therefore, the rotating shaft includes up to the alternator section, and the vacuum pump drive section is unnecessary, and the configuration is such that the vacuum pump 6, oil seal 22, and vacuum pump drive section 7B are removed from FIG. The rotating shaft 7 of the alternator for a diesel engine vehicle according to the above-described embodiment of the present invention is inserted into the engagement hole 20a of the shaft 20, which is the rotating shaft of the alternator section for the gasoline engine vehicle described above. Further, a separately molded shaft 10 constituting the vacuum pump drive section 7B is directly connected in the longitudinal direction.

In other words, the rotating shaft for gasoline engine vehicles is commonly used as the rotating shaft for the alternating current generator section for diesel engine vehicles.

Here, the shaft 10, which is a press-fitted shaft having a solid cylindrical shape, is made of steel and is formed by extrusion molding and sawing process.

This shaft 10 includes a first cylindrical portion 10a1 and a plurality of protrusions 10b.
1, a second cylindrical portion 10c and a serration portion 10d. The second cylindrical portion 10c on which the oil seal 17 slides is subjected to induction hardening. The diameter of the first cylindrical portion 10a is 8Tr0n1. The diameter of the second cylindrical portion 10c is slightly larger than the diameter of the first cylindrical portion 10a8.
It is 4Trrm. Here, the protrusion 10b will be explained in detail.

As shown in FIGS. 6 and 7, the protrusion 11 is located at the first
It is formed to protrude from the outer peripheral part of the cylindrical part 10a. In this case, the protrusion 11 of the protrusion 10b is provided on a cylindrical portion having the same diameter as the outer circumference (circular cross section) of the first cylindrical portion 10a. A first cylindrical portion 10 from which this protrusion 11 protrudes.
The circle on the outer periphery of a will be referred to as the reference circle of the protrusion 11. The projections 11 extend linearly in the longitudinal direction on the shaft 10, and are provided parallel to each other at equal intervals (n=12).

The specifications of this protrusion 11 are as follows: length in the longitudinal direction, which is the press-fitting length, l=12WrIn, protrusion height h=0.27 m, protrusion base length S=0.4WrIn, and protrusion angle 0=600. The cross-sectional shape of the protrusion 11 is bilaterally symmetrical, and the top portion 12 thereof has an arc shape.

Further, the entrance portion of the protrusion 11 is located on the inclined plane 1 at an angle γ=30.
3 is formed. The protrusion 11 has flat surfaces 14, 1 on both sides.
5 is formed.

Further, the second cylindrical portion 10c and the terminal end of the protrusion 11 are continuous. Between the adjacent protrusions 11 at the terminal ends of the protrusions 11, a second
An inclined plane is formed at the tip of the cylindrical portion 10c.
As described above, regarding the protrusion 10b, the diameter of the reference circle is 8 mm, the height of the protrusion h is 0.27 m, and the top 12 is at the height of the second cylindrical portion 10c (diameter 8 mm).
4 ugliness) is located on the same plane. Further, the shaft 20, which is a press-fitted shaft into which the shaft 10 is press-fitted, has a hole 20a at its end into which the projection 10b of the shaft 10 is press-fitted.

The diameter DO of the outer peripheral portion of the shaft 20 is 12wn, and the diameter D of the wall portion 20b formed by the hole 20a of the shaft 20 is 8wn, and the diameter DO of the first cylindrical portion 10a of the shaft 10 is 8wn. is the same as Here, the wall 20 of the hole 20a of the shaft 20
The diameter D of b is called the reference circle of the axis 20.

In this case, the reference circle of the shaft 20 has the same size as the reference circle of the protrusion 11 of the shaft 10. The material of the shaft 20 is soft steel, which has a lower deformation resistance (softer material) than the material of the shaft 10.

Next, a process of coupling the shaft 10 and the shaft 2''0 having the above-described configuration will be explained.

First, the shaft 20 is placed on a shaft mounting table that prevents the shaft 20 from moving in the left-right direction and downward direction.

On the other hand, the shaft 10 is held by a claw of a hydraulic cylinder device. This shaft 10 and the shaft 20 of the mounting table are set so that their centers are aligned in the upward and downward directions. The shaft 10 is then moved downward by a hydraulic cylinder device with a pressing force of about 300 to 400 kg. First, the first cylindrical portion 10a of the shaft 10 is inserted into the hole 20a of the shaft 20. At this time, the first
There is no contact between the cylindrical portion 10)a and the wall 20b of the hole 20a of the shaft 20. The entrance portion of the protrusion 11 of the shaft 10 is then inserted into the shaft 20.

Here, the inclined plane 13 of the protrusion 11 performs its function.
That is, since the inclination angle γ is set to 30, the subsequent protrusion 11 that is subsequently inserted can smoothly come into contact with the wall 20b of the hole 20a of the shaft 20 and come into close contact with it.
The smooth guiding action of the inclined plane 13 at the entrance of the protrusion 11 and the fact that the reference circles of the shafts 10 and 20 are the same combine to provide high centripetal accuracy between the shafts 10 and 20. Further, the shaft 10 starts contacting the shaft 20 from the middle of the entrance of the protrusion 11 of the shaft 10.

Then, as the shaft 10 moves downward, the protrusion 1 of the shaft 10
The inlet portion of 1 is inserted into a shaft 20 made of a material with low deformation resistance. Finally, the top of the protrusion 11 of the shaft 10 is connected to the shaft 2.
0, and thereafter the protrusion 11 of the shaft 10 is wedged into the shaft 20. The portion of the shaft 20 that is pressurized and pushed outward by the projection 11 of the shaft 10 undergoes plastic deformation as the material around the projection 11 of the shaft 10 flows out.

In this way, the shaft 10 plastically deforms the shaft 20, and the protrusion 11 of the shaft 10 and its surroundings are in close contact with the shaft 20.
It is press-fitted into the At this time, the material between adjacent protrusions 11 of the shaft 10 of the shaft 20 is heaped up in the direction in which the diameter increases from the reference circle of the shaft 20, in other words, outward from the reference circle of the protrusions 11 of the shaft 10. It will be done.

The resulting gap δ between shafts 10 and 20 is approximately 0
．． 02wr! It was hot. Note that the time required for these series of joining processes is approximately 1 second after the shafts 10 and 20 are set, and the joining operation is completed.

Through the above bonding process, the rotating shaft 7, which is a metal bonding structure of the shaft 10 and the shaft 20 as shown in FIGS. 3 and 4, is completed.

The state in which the shafts 10 and 20 are tightly coupled will be considered. This can be seen in the (a) magnified photograph in Figure 8 and the 100x magnified photograph in Figure 9, which show the condition around the joint. In addition, the shafts 10 and 20 exhibit a characteristic coupling state. That is, the wall portion 20b of the shaft 10 and the shaft 20 is defined by the protrusion 11 of the shaft 10 excluding the inclined plane 13, the top portion 12,
Of course, the side surfaces 14 and 15 are in close contact with the reference internal portion 18a around the protrusion 11.

The shaft 10 and the shaft 20 are part of the reference inner portion 18b that is located between the adjacent protrusions 11, and are separated from each other and do not contact each other. To further explain this bonding state using FIG. 10,
The shaft 10 and the shaft 20 are in perfect contact with each other at the peripheral portion including the shaft 10 and the protrusion 11, but in the intermediate region between the adjacent projections 11, the reference inner portion 18b of the shaft 10 and the shaft 20 are in close contact with each other. There is a gap between them.

The distance δ between the shafts 10 and 20 is approximately 0.02? , and the distance h between the top 12 of the protrusion 11 of the shaft 10 and the shaft 20 is approximately 0.
．． 2Tn1n.

Such a unique bonding state around the coupling portion of the rotating shaft 7 is as follows.
Since the shaft 10 has higher deformation resistance than the shaft 20, the shaft 20
This can be said to occur as a result of plastic deformation of the shaft 20, which has low deformation resistance, whereas the external shape does not change even if the shaft is press-fitted into the shaft.

In the rotating shaft 7 described above, as shown in FIG.
A tension force P1 is acting on the inside of the close contact portion.

This tightening force P1 firmly presses and expands the top 12, side surface 14, side surface 15 of the protrusion 11 of the shaft 10, and the portion 18a that is in contact with the shaft 20 at the reference circle of the shaft 10. Also axis 10
An extremely large shearing force P2, which is the product of the shear strength of the material of the projection 11 of the shaft 10 and the shear area, is generated between the shaft 20 that is in close contact with the top 12, side surface 14, and side surface 15 of the projection 11 of the shaft 10. ing.

In this manner, in this embodiment, the alternating current generator for a diesel engine is constructed by integrating the rotating shaft and incorporating various parts into the rotating shaft.

The above embodiments of the present invention have the following effects.

(1) Intermittent 8 that protrudes from the reference circle and extends in the longitudinal direction
The shaft 10 on which the projections 11 are formed is press-fitted into the shaft 20 having a hole 20a of the same size as the reference circle of the shaft 10, and the shaft 20 is plastically deformed to make the shaft 10 and the shaft 20 mechanically strong. A rotating shaft 7 was obtained. In this way, according to the above-mentioned embodiment of the present invention, it is 4.3k9·m and, for example, the knurling press-fitting method is
A rotary shaft 7 having a rotational torque more than twice as high is obtained, and this rotational torque is equal to or exceeds the rotational torque obtained by a fitting connection.

Therefore, the rotary shaft 7 obtained by joining the two shafts 10 and 20 has a mechanically strong joint part compared to a conventional rotary shaft for mounting a diesel engine, which has an integral structure. It was confirmed that it can be used practically.

(2) The shaft 10 and the gear shaft are the top 1 of the protrusion 11 of the shaft 10.
2. Axis 20 on the reference circle of side 1 male side 15 and axis 10
At the part 18a that is in close contact with the shaft 20, a tension force P1 is applied inside the contact part of the shaft 20, and the contact part of the shaft 10 is firmly pushed and expanded, so that the required tension force P1 can be applied.
A rotating shaft 7 having a mechanically stable and strong bonding force between the shafts 10 and 20 was obtained.

(3) The protrusion 11 of the shaft 10 is in close contact with the shaft 20 and the top 12, the side surface 14, and the side surface 15 of the protrusion 11 of the shaft 10.
An extremely large shearing force P2, which is the product of the shearing stress of the material and the shearing area, is generated, and a rotating shaft 7 having a mechanically stable and strong bonding force between the shafts 10 and 20 is obtained. Furthermore, a rotating shaft 7 that generates a large twisting force even when there is a twisting action was obtained.

(4) Since the inclination angle γ of the inclined plane 13 of the protrusion 11 of the shaft 10 is set to 301, the subsequent protrusion 11 can smoothly come into contact with the wall 20b of the hole 20a of the shaft 20 and be brought into close contact with it. .

Furthermore, the centripetal accuracy between the shafts 10 and 20 could be improved.

Since this centripetal precision is improved, there is no wobbling between the shafts 10 and 20, and a rotating shaft 7 with high durability can be obtained. (5) Since the reference circle of the shaft 10 and the reference circle of the shaft 20 are the same and the accuracy of this reference circle is high, the centripetal precision is maintained high between the reference circles, so that the reference circle of the shaft 10 and the shaft 20 is A rotating shaft 7 with high centripetal accuracy was obtained.

(6) Shaft 10 has greater deformation resistance (harder) than axis 20
Because of the material, the shaft 10 is not distorted by pressurization and plastic flow, and high precision is maintained.

(7) By providing the above-mentioned reference circle on the rotating shaft 7 of the shaft 10 and the gear 20, it is possible to prevent the shaft from bending and improve assembly accuracy.

(8) First cylindrical part 10a1 protrusion 10b1 second cylindrical part 1
0c and a serration portion 10d.
0 can be finished in one step of plastic working, resulting in good material yield and improved productivity.

(9) Although induction hardening is applied to the second cylindrical portion 10c of the shaft 10 on which the oil seal 17 slides, since the axial length of the shaft 10 is short, almost no bending occurs due to hardening.

(11 Since the rotating shaft 7 was constructed by combining two shafts, the shaft 20 and the shaft 10, a high material yield and high productivity were obtained.

(11) Since the shaft 20, which is the rotational shaft for a gasoline engine, can be shared as the rotational shaft of the alternator section for a diesel engine, the material yield and productivity are good, and the productivity of the processing line for the rotor 1 is also high. was gotten.

Next, regarding the press-fit connection by plastic deformation between the shafts,
In order to find the optimal rotating shaft and coupling method, the inventors investigated the relationship between shaft members and their optimal specifications from various angles.

The results of this study will be explained below. First, we will discuss the test materials.

As shown in FIGS. 11 and 12, the shaft A, which is a press-fitting member, is made of steel. Further, the shaft B, which is a press-fitted member, is made of mild steel. On the axis A, n protrusions p are provided at regular intervals on a reference circle having a diameter Da.

The specifications of the protrusion p are as shown in Fig. 12, where the press-fit length is E.
The height of the al protrusion and the angle of the Hal protrusion are θ. , the protrusion base length is S
Represented by a. Further, as shown in FIG. 11, the outer diameter of the shaft B is D. Let the inner diameter be D1. First, the influence of the size of the protrusion angle 0a of the protrusion p on the axis A was studied.

That is, an experiment regarding the magnitude of the press force P required to press fit the shaft A to the shaft B, and the magnitude of the rotational torque (transmission torque) T possessed by the rotating shaft that is the coupling structure of the shafts A and B. The results were as shown in FIG.

In this case, the reference circle diameter Da of axis A = 8Tfn1 the outer diameter D of axis B.

=12 order, inner diameter D, =8wn was selected. protrusion p
The specifications are: number of protrusions n = 8, press-fit length 11 = 12 mm, protrusion height H3 = 0.2 length, and protrusion base length Sa = 0.477
! 77! The one was adopted. In Figure 13, the protrusion p
The curve X1
indicates the magnitude of the rotational torque T, and curve X2 indicates the magnitude of the press force P, respectively. Based on this experimental result, the protrusion angle θ1 of the protrusion p provided on the reference circle of the axis A is approximately 4
It has been found that a range of 0 to 70 is preferable.

Furthermore, an experiment was conducted to examine the influence of the number n of protrusions p provided on the axis A.

Figure 14 shows the relationship between axis A and axis B depending on the number n of protrusions p on axis A.
It shows the magnitude of the rotational torque T possessed by the rotating shaft that is the coupling structure with the .

That is, in FIG. 14, the curve X3 represents the rotational torque T.
represents the size of.

In this case, the reference circle diameter d1 of axis A is 8Tf0n1, the outer diameter D3 of axis B is 12Tf0f11, and the inner diameter D is 8wun.

Further, the specifications of the protrusion p are: press-fit length Ea = 12 types, protrusion height H. =0.2w$t, protrusion angle θ. =60 protrusion base length S
The one with a=0.4TfUn was adopted. According to the results of this experiment, when the number n of protrusions p was 16 or more, the rotational torque T became constant because the shaft A was damaged or deformed, making it unusable. From this experimental result,
Considering the magnitude of the rotational torque T obtained, the protrusion p
The number of protrusions n: 8 to 16 (an integer of 7) was found to be an appropriate numerical range.

In addition, in this case, when comparing the number n of protrusions p and the reference circle diameter D3 (unit: Wn) of the axis A, it is 213 to 111.
A range of 3 is preferred. In addition, the influence of the height Ha of the protrusion p provided on the reference circle of the axis A was investigated. In Fig. 15, curve X4 corresponds to protrusion height H8.
The figure shows the magnitude of the rotational torque T of the rotational shaft of the coupling structure of the shafts A and B according to the above.

In this case, the reference circle diameter Da of axis A = 8TWL1 the outer diameter D of axis B.

=12TWL, inner diameter D1=8Wr! I selected n. In addition, the specifications of the protrusion p are as follows: number of protrusions n=8, press-fit length Ea
=12Trr! n, protrusion angle θ1 = 600, protrusion base length Sa = 1.5F1a and protrusion height Ha
The following parameters were adopted. According to this experimental result, the protrusion height Ha of the protrusion p is 0.55Tfr! It has been found that if the size is larger than n, the shaft A will be damaged or deformed and cannot be put to practical use.

From this experimental result, considering the magnitude of the rotational torque T obtained, the protrusion height Ha is Ha=0.1
A range of 5 to 0.55 wrm has been found to be preferred.
Furthermore, as shown in FIG. 14, it has been found that the protrusion height Ha of the protrusion p has a great effect on the magnitude of the rotational torque T.

The protrusion height h1 of the protrusion p can be determined according to the required rotational torque T. Note that when the protrusion height Ha of the protrusion p was 0.55 mm, the distance δ between the axis A and the axis B was about 0.04 mm.

Also, considering the above results, the protrusion base length Sa of the protrusion p
is preferably in a range of 1.3 to 3 times the protrusion height Ha. Taking all the above study results into consideration, it is recommended that the following rotation shaft be selected as the optimal joint structure.

In other words, the specifications of the protrusions provided on the shaft member with high deformation resistance are such that the number of protrusions is within the appropriate range of 8 to 16S, considering the magnitude of the rotational torque obtained, and the standard circle of the shaft member with high deformation resistance. In terms of diameter (unit: WOn) ratio, a range of 213 to 11'3 is preferable. Moreover, the protrusion angle of the protrusion of the shaft member is preferably in the range of about 40 to 700, considering the magnitude of the rotational torque and pressing force that can be obtained. Also, considering the magnitude of rotational torque, the protrusion height is 0.1
5~0.55T! r! It has been found that a range of n is preferable, and that this protrusion height has a large effect on the magnitude of the rotational torque that can be obtained.

Further, the length of the protrusion base of the protrusion is preferably within a range of 1.3 to 3 times the protrusion height.

In addition, when we examined the size of the reference circle of the shaft member that forms the protrusion and the reference circle of the shaft member that undergoes plastic deformation, we found that the reference circle of the latter shaft member is the same as the reference circle of the former shaft member. , or the reference circle needs to be slightly larger.

According to experiments, it has been found that the gap between the reference circle of the latter shaft member and the reference circle of the former shaft member having a protrusion is preferably 0 to 0.1 in size.

Furthermore, if the inlet of the protrusion of the shaft having the protrusion is made into an inclined plane and the inclination angle is about 15 to 45, the shaft can be smoothly inserted into the press-fitted shaft.

In the present invention, the material of the second rotating shaft that forms the protrusion is required to be harder and have greater rigidity than the material of the second metal member that undergoes plastic deformation.

This is because, while the first rotating shaft is pressurized and undergoes plastic flow, the second rotating shaft must not be deformed and must be sufficiently rigid. In other words, the first axis of rotation is the second
The material must have a lower deformation resistance (softer material) than the rotating shaft.

For example, when the second rotating shaft is made of steel, the first rotating shaft is
Preferably, aluminum, brass, copper, mild steel, etc. are used. In the example, an alternator for a diesel engine vehicle was constructed by assembling the various parts after the shaft was integrated. It goes without saying that it is also possible to press-fit a single unit to form a rotating shaft for a diesel engine vehicle, and then assemble various parts of the vacuum pump section to construct an alternator for a diesel engine vehicle.

As described above, according to the present invention, a shaft engagement recess is provided at the end of the first rotating shaft for a gasoline engine vehicle, and an intermittent protrusion that protrudes from the reference circle and extends in the longitudinal direction is provided in the engagement recess. The second rotating shaft having a device drive part is plastically press-fitted, and the first rotating shaft and the second rotating shaft are connected by tension force and shearing force. A rotating shaft of a vehicle alternator which can be used commonly as the rotating shaft of an alternator section for a diesel engine vehicle was obtained.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view of an alternator for a diesel engine vehicle showing an embodiment of the present invention, and Fig. 2 shows only the vacuum pump portion of the alternator for a diesel engine car shown in Fig. 1. A side view seen from the right side, Fig. 3 is a plan view of the rotating shaft of the alternator for diesel engine vehicles, and Fig. 4 is an enlarged partial cross-section of the connecting part of the rotating shaft for diesel engine vehicles shown in Fig. 3. Figure 5 is a perspective view of the rotating shaft for a vacuum pump drive unit for a diesel engine vehicle, Figure 6 is a partially enlarged perspective view of the protrusion in Figure 5, and Figure 7 is a perspective view of the rotating shaft in Figure 5. An enlarged explanatory diagram of the protrusion, FIG. 8 is a 5-dimensional enlarged microscopic photograph showing the state of connection around the protrusion of a rotating shaft for a diesel engine vehicle,
FIG. 9 is a 1 (1) times magnified micrograph showing the connection state around the protrusion, FIG. 10 is an enlarged explanatory view showing the connection state of the rotating shaft for a diesel engine vehicle, and FIG. 11 is a diesel engine of the present invention. A partial cross-sectional explanatory diagram of a test shaft for determining the specifications of a rotating shaft for an engine vehicle. Figure 12 is a schematic diagram of a shaft that is a press-fit member. Figure 13 is a diagram showing the protrusion angle θ of the shaft that is a press-fit member. A comparative study diagram showing the magnitude of the rotational torque T and the magnitude of the press force P when used as a parameter, and Fig. 14 shows the magnitude of the rotational torque T when the number n of protrusions on the shaft, which is a press-fitting member, is used as a parameter. Figure 15 is a comparative diagram of the magnitude of rotational torque T when the height h of the protrusion of the shaft, which is a press-fitted member, is taken as a parameter. FIG. 17 is a plan view of a conventional rotating shaft for a gasoline engine vehicle. 1... Rotor, 2... Stator, 3, 4... Bracket, 5... Pulley, 6... Vacuum pump, 7...
・Rotating shaft, 7A... Alternating current generator part, 7B... Vacuum pump drive part, 10... Axis, 10b... Protrusion part, 20
...shaft, 20a...hole.

Claims (1)

[Scope of Claims] 1. A first rotating shaft, a rotor attached to the first rotating shaft, a stator provided on the outer periphery of the rotor, and a bracket arranged to surround the rotor and stator; In a vehicle alternator comprising a pulley attached to one end of the first rotation shaft, the first a second rotating shaft, which is made of a material with greater deformation resistance than the first rotating shaft, has intermittent protrusions that protrude from the reference circle and extend in the longitudinal direction, and has an equipment drive unit that is directly connected to and driven by the alternator; Only the protrusion of the second rotation shaft and its vicinity are brought into close contact with the first rotation shaft, and the tension force generated at the close contact portion and the shearing force of the protrusion of the second rotation shaft cause the first rotation shaft and the second rotation shaft to A rotating shaft of a vehicle alternator, characterized in that: 2. In the item described in claim 1, the device is a rotating shaft of a vehicle alternator, which is a vacuum pump. 3 In the item described in claim 1, the specifications of the protrusion of the second rotating shaft are such that the number n of protrusions is (2/3 to 11/3).
) D (here, D is the diameter of the second rotating shaft in mm; the number of protrusions n is an integer), the protrusion angle θ is 40 to 70°, the protrusion height h is 0.15 to 0.55 mm, and the protrusion A rotating shaft of an alternator for a vehicle, characterized in that an original length s is (1.3 to 3) h. 4. In the item described in claim 1, the entrance portion of the protrusion of the second rotating shaft is an inclined plane, and the inclination angle is approximately 1.
A rotating shaft of an alternator for a vehicle, characterized in that the angle is 5 to 45 degrees. 5. In the device described in claim 1, the gap between the reference circle of the first rotating shaft and the reference circle of the second rotating shaft is 0 to 0.
The rotating shaft of a vehicle alternator is 1mm in size.