JP2767542B2 - Processing method of rotor shaft with lead screw - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for machining a rotor shaft with a lead screw, which is used, for example, for a rotor shaft of a lead screw type stepping motor.

[0002]

2. Description of the Related Art Conventionally, for example, a lead screw type stepping motor (hereinafter simply referred to as a motor) used for a head feed of a floppy disk drive device is configured as shown in FIG. 4, for example. That is, the motor 1 has a stator 2 and a rotor 3, and the main part of the stator 2 is constituted by a pair of stator yokes 4, 5 surrounding the rotor 3. Each of the stator yokes 4 and 5 is a combination of two sheet metal parts. A donut-shaped space for accommodating the exciting coils 6 and 7 is formed, and a portion facing the outer side surface of the rotor 3 is formed. , A pole tooth row (not shown) of a claw pole structure is formed.

The rotor 3 is formed of a cylindrical permanent magnet whose magnetic poles are magnetized at a predetermined pitch in the circumferential direction, and a metal rotor shaft 8 is fixed at the center thereof. The rotor shaft 8 is supported by a bearing 9 at a substantially central portion thereof, abuts against a leaf spring 11 via a ball 10 at a rear end, and is supported by a ball bearing 13 via a ball 12 at a distal end. . Thus, the rotor 3 is rotatably disposed in the stator 2 while the rotor shaft 8 receives a compressive force in the axial direction by the leaf spring 11. The bearing 9 is fixed to a front flange 14 fixed to the stator yoke 4,
And the ball bearing 13 include the stator yoke 5 and the front flange 1.
4 are fixed to the inner surface of the rear end and the inner surface of the distal end of the motor frame 15, respectively.

A lead screw 16 is engraved on the outer periphery of the tip end side of the rotor shaft 8.
Head of floppy disk drive (not shown)
Is connected to the moving body 17. Then, by the rotation of the lead screw 16 caused by the rotation of the rotor 3, the moving body 17 moves linearly along the axial direction of the rotor shaft 8. In order to prevent the rotor 3 from rotating relative to the rotor 3 at the rear end side of the rotor shaft 8 to which the rotor 3 is fixed, a D-cut rotation preventing portion 18 as shown in FIG. A detent portion 19 for the traverse cut is formed. Then, the rotor 3 is fixed to the outer periphery of the detent portions 18 and 19 via the resin 20.

[0005]

However, the rotor shaft 8 has a problem that the number of processing steps is increased and the product cost is increased. That is, since the detent portions 18 and 19 have a D-cut or twill cut shape different from that of the lead screw 16, the processing of the lead screw 16 and the detent portions 18 and 19 are performed by different processing machines. Need to be processed. As a result, the processing is performed in a separate step, the number of processing steps is increased, and the product cost is increased.

[0006] The present invention has such has been made in view of the circumstances, and an object, by processing continuously with the same machine the lead screw and the detent portion, to reduce the number of processing steps by product Cost reduction and low
A reliable detent effect on the rotor shaft of the rotor
An object of the present invention is to provide a method of processing a rotor shaft with a lead screw.

[0007]

In order to achieve the above object, according to the present invention , a lead screw capable of converting a rotary motion of a rotor into a linear motion is machined at one end of a shaft main body. In the method of processing a rotor shaft with a lead screw for processing a detent part for preventing relative rotation with the rotor on the other end side of the main body, after setting the shaft main body in a processing machine, at least the lead screw , the screw, and the screw one
The non-rotating portion formed of a deep groove provided on the end side is continuously processed by the same processing machine. The invention according to claim 2 is characterized in that one end side of the shaft main body is provided with a rotational movement of the rotor.
Processing a lead screw that can convert motion into linear motion,
Around the other end of the shaft body to prevent relative rotation with the rotor
Machining of rotor shaft with lead screw for machining stop
In the method, after setting the shaft body to the processing machine,
The screw and the detent part consisting of cross screws are the same
It is characterized by processing continuously with a processing machine .

[0008]

First, according to the first aspect of the present invention , the shaft body is set in the processing machine, and for example, a lead screw is machined on one end side while the other end side of the shaft body is chucked. Next, with the same processing machine, chuck the lead screw,
Screw on the other end of the shaft body and at least one end of this screw
The detent part consisting of the provided deep groove is processed. Since the lead screw and the detent are continuously processed by the same processing machine, the number of processing steps is reduced and the detent is prevented.
Is formed by the screw and the deep groove.
The rotation of the attached rotor against the shaft
You. According to the invention of claim 2 , according to claim 1,
Like the invention of the above, the lead screw and the detent are attached to the shaft body.
Part is formed, and the detent part is formed with a cross screw
The rotation of the rotor with respect to the shaft
Become.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a side view of a rotor shaft with a lead screw according to the present invention. This rotor shaft 2
2 is applied to the motor 1 shown in FIG. 4, for example.

The rotor shaft 22 has a shaft main body 22a made of, for example, stainless steel (SUS303 or the like). A lead screw 23 is formed on the outer periphery of one end (tip side) of the shaft main body 22a, and the other end is formed. On the (rear end side), a rotation preventing portion 24 for preventing rotation of the rotor 3 and movement in the axial direction is formed. The anti-rotation part 24 includes a single screw 24a and deep grooves 2 formed at both ends of the screw 24a.
4b and 24c, and the shape of the screw 24a, such as the twist direction and the screw pitch, is formed to be the same as a part of the shape of the lead screw 23. The deep grooves 24b and 24c are formed at both ends of the screw 24a in the entire circumferential direction.
It is formed slightly deeper than the valley diameter of a.

The rotor 3 is fixed to the outer periphery of the rotation preventing portion 24 via the resin 20 in the rotor shaft 22 as in the conventional example shown in FIG. A concave portion 25 and a concave portion 26 for accommodating the balls 12 and 10 (see FIG. 4) are formed on one end surface and the other end surface of the rotor shaft 22.

Next, an example of a method of processing the rotor shaft 22 will be described with reference to the process chart of FIG. This step shows a case in which an NC turning lathe (not shown) that has a work reversing device and cuts a work with a cutting tool or a drill is used as a processing machine. First, a shaft main body 22a cut to a predetermined length is prepared, and the other end side of the shaft main body 22a, that is, the detent portion 24 side is chucked to a chuck of a processing machine (K100). When the shaft body 22a is chucked, the cutting tool is set at a predetermined position,
The shaft body 22a is moved in the axial direction while rotating. Thus, the lead screw 23 is cut by the cutting tool on the outer peripheral surface on one end side of the shaft main body 22a (K10).
1).

When the machining of the lead screw 23 is completed, the cutting tool is separated from the shaft main body 22a, and the drill is brought into contact with the end face of one end of the lead screw 23 so that the recess 2 is formed.
5 is processed (K102). Then, the processed lead screw 23 is chucked by the work reversing device,
For example, the shaft main body 22a is rotated 180 degrees in a vertical plane to invert (K103). When the shaft main body 22a is inverted, the lead screw 23 at one end is chucked (K10
4) Yes. In this state, the cutting tool is set at a predetermined position, the shaft body 22a is rotated, and the deep groove 24b is cut by the cutting tool (K105). At this time, the shaft main body 22a
Do not move in the axial direction.

Thereafter, the shaft body 22a is moved in the axial direction while rotating, and the screw 24a of the rotation preventing portion 24 is cut by a cutting tool (K106). At this time, the cutting tool is set under substantially the same conditions as those for processing the lead screw 23. Then, the movement of the shaft main body 22a is stopped,
On the other end side of the screw 24a, a deep groove 24c is machined in the same manner as the deep groove 24b (K107). After that, similarly to the processing of the concave portion 25, the concave portion 26 is processed (K108) on the other end side end surface of the shaft main body 22a by a drill. After the processing of the concave portion 26 is completed, the chuck on one end side of the shaft main body 22a is released, whereby the processing of the rotor shaft 22 by the processing machine is completed.

Steps K100 to K108 are automatically executed by the NC unit of the processing machine.
If the cutting of the shaft main body 22a, the setting to and removal from the processing machine, and the like are automated, the processing of the rotor shaft 22 can be fully automated. Further, for example, the steps of setting, removing, and inverting the shaft main body 22a to the processing machine may be performed manually, or the processing of the recesses 25 and 26 may be performed by another processing machine. Further, the lead screw 23 may be processed after the rotation preventing portion 24 has been processed. In this case, the lead screw 23 is prevented from being damaged by the chuck.

The processing of the rotor shaft 22 is not limited to cutting with a cutting tool. For example, the lead screw 23 and the detent portion 24 are continuously processed by grinding with a grindstone. The type of processing machine, such as supporting the other end surface on the processing side of the core extrusion center,
It goes without saying that various processing methods according to the performance and the like can be applied.

As described above, in the above embodiment, the lead screw 23 and the detent portion 24 of the rotor shaft 22 are continuously processed by one processing machine. However, the number of steps such as the step of moving from one processing machine to another processing machine and the step of attaching and detaching the shaft main body 22a to and from each processing machine can be reduced, thereby reducing the number of processing steps. Especially,
Since the rotation preventing portion 24 has a screw portion 24a having the same torsion direction, screw pitch, and the like as the lead screw 23, the processing conditions of the rotation preventing portion 24 are set to the lead screw 2
3, and can be set in the processing machine, for example,
The number of steps for adjusting the position of the cutting tool can be reduced, and the number of processing steps can be further reduced. Thus, the manufacturing cost is reduced, and the cost of the motor 1 can be reduced.

The rotation preventing portion 24 includes a screw 24a and deep grooves 24b and 24c formed at both ends of the screw 24a.
, The rotor 3
Is prevented from moving in the rotation direction with respect to the deep grooves 24b and 24.
The movement in the axial direction, that is, the detachment is prevented by c.
And the like, with respect to the shaft body 22a of the rotor shaft 22 of the rotor 3
A real detent effect can be obtained.

In particular, the resin 20 may be provided with a screw 24a or a deep groove 24.
Since the rotor shaft 22 and the rotor 3 are firmly adhered to each other by being interposed in the b and 24c, the rotor 3 rotates with respect to the rotor shaft 22 due to cracks in the resin 20 caused by an external temperature change or the like. Occurrence can be reliably prevented. Furthermore, during processing, substantially the same weight is applied to both ends of the rotor shaft 22, and this weight can be reduced, so that occurrence of troubles such as bending of the rotor shaft 22 can be prevented. As a result, the quality and reliability of the rotor shaft 22 can be improved, and a high-quality rotor shaft 22 can be obtained.

FIG. 3 is a side view showing another embodiment of the rotor shaft 32 with a lead screw according to the present invention. This embodiment is characterized in that a rotation preventing portion 34 formed of a cross screw is formed on the other end of the shaft main body 32a of the rotor shaft 32. That is, the rotation preventing portion 34 is a single screw 3 having the same twist direction as the screw of the lead screw 33.
4a and one screw 34b intersecting the screw 34a. The screw pitch between the screw 34a and the lead screw 33 is different, but may be the same. Also in this embodiment, the screw 34a and the screw 34b prevent the rotor 3 from rotating and coming off, so that the rotor 3 is reliably prevented from rotating with respect to the rotor shaft 32.
The same operation and effects as those of the above embodiment can be obtained, such as effects.

In each of the above embodiments, the rotor is fixed to the rotation preventing portion of the rotor shaft via the resin. However, for example, the rotor is formed by integrally molding a plastic magnet resin on the outer periphery of the rotor shaft. Is also good. Also,
In the above embodiment, the rotor shaft is applied to a stepping motor for a floppy disk drive device, but may be applied to a stepping motor for an autofocus camera or a mini disk. Further, the shape of the detent portion is not limited to the above embodiments, and it goes without saying that various changes can be made without departing from the spirit of the present invention.

[0022]

As described above in detail, in the method of machining a rotor shaft with a lead screw according to the present invention, since the lead screw and the detent portion are continuously machined, the number of machining steps can be greatly reduced. , Figure the cost of the product
Screw and deep groove or cross screw
Of the rotor with respect to the rotor shaft
A reliable detent effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a side view showing a rotor shaft with a lead screw according to the present invention.

FIG. 2 is a process chart showing an example of the processing method.

FIG. 3 is a side view showing another embodiment of the rotor shaft with a lead screw according to the present invention.

FIG. 4 is a sectional view of a lead screw type stepping motor common to the present invention and a conventional example.

FIG. 5 is a sectional view of a rotor using a conventional rotor shaft with a lead screw.

FIG. 6 is a sectional view of a main part of a rotor showing another conventional example.

[Explanation of symbols]

 1 ··· Motor 2 ··· Stator 3 ··· Rotor 8 ···· ····· Rotor shafts 18 and 19 ····· Detent part 20 ··· Resin 22 and 32 ······ Rotor shafts 22a and 32a ····· Shaft main body 23, 33 ······ Lead screw 24, 34 ······ Detent part 24a, 34a, 34b ··· Screw 24b, 24c ··· ..Deep grooves

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B23B 5/48 B23G 1/00 H02K 7/06 H02K 37/24 F16H 25/20

Claims (2)

(57) [Claims] 1. A lead screw capable of converting a rotary motion of a rotor into a linear motion is machined at one end of a shaft main body, and a detent portion for preventing relative rotation with the rotor is formed at the other end of the shaft main body. In the method for processing a rotor shaft with a lead screw to be processed, after setting the shaft main body in a processing machine, the lead screw , a screw, and at least one end of the screw
A method for processing a rotor shaft with a lead screw, comprising: continuously processing a detent portion formed of a deep groove provided on a rotor with the same processing machine. 2. A rotary motion of a rotor is directly applied to one end of a shaft body.
Process lead screw that can be converted to linear motion
The other end of the rotation stop that prevents relative rotation with the rotor
Of the rotor shaft with lead screw for machining the female part
In the method, after setting the shaft body in a processing machine,
A detent part consisting of a lead screw and a cross screw
Are continuously machined by the same machine .