JPH0648371U - Motor pulley - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a pulley for a motor that is inexpensive and excellent in accuracy, rigidity, and conductivity. [Structure] A pulley of a motor, which is fixed to a rotor portion 4 facing a stator portion and rotates integrally with a rotating shaft 2, and which drives a belt 2 by the pulley, has two pulleys.
It is composed of two members, and at least one of them is a plate made by pressing a metal plate.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a motor pulley applicable to, for example, a capstan motor of a video tape recorder.

[0002]

[Prior art]

 For example, there is a brushless capstan motor as a motor for driving a tape of a video tape recorder or the like. FIG. 11 shows a conventional example of such a brushless capstan motor. In FIG. 11, the bearing housing 31 has a through hole 31a in the center, and a stator core 33 is attached to the outer peripheral surface. The stator core 33 has a plurality of salient poles on its outer circumference, and a coil 34 is wound around each salient pole. Bearings Inside the through hole 31a formed in the central portion of the housing 31, two upper and lower bearings 38, 38 are mounted. A rotary shaft 32 is inserted into a through hole at the center of the bearings 38, 38, and the rotary shaft 32 is rotatable with respect to the bearing housing 31 by the bearings 38, 38. A rotor case 36 is attached to the upper end of the rotary shaft 32. The rotor case 36 has a flat cup shape, and a rotor magnet 35 is attached to the inner side of the peripheral wall, and a pulley 37 is attached to the protruding portion of the central portion of the bottom plate. The inner side of the rotor magnet 35 faces the salient poles of the stator core 33 with a gap. For this reason, when the coil 34 wound around each salient pole of the stator core 33 is energized, the rotor magnet 35 is energized, and the rotor 36, the pulley 37, and the rotary shaft 32 are driven to rotate. A peripheral groove 37 a is formed on the outer peripheral surface of the pulley 37, on which the belt is hooked.

As the pulley 37 used in the capstan motor having the above-described structure, aluminum or brass is formed by cutting, a central boss portion is formed by using a sintered member, and conductive material is provided on the outer peripheral portion. There is a resin resin pulley fitted and a resin case formed by resin outsert molding.

[0004]

[Problems to be solved by the device]

 In the conventional motor as described above, when the rotary shaft 32 rotates, the pulley 37 integrated with the rotary shaft 32 is rotationally driven, and the belt (not shown) wound around the circumferential groove 37a is driven. When the belt is driven, static electricity is generated by the frictional resistance between the pulley 37 and the belt. When the pulley 37 is made of a conductor such as metal, there is no problem because the generated static electricity can be released to other parts. However, when the pulley 37 is made of an insulator such as resin, Since static electricity cannot be released, dust or the like scattered in the air may adhere to the surface of the pulley 37, which may hinder belt driving.

When the pulley 37 is formed by cutting a conductive member such as aluminum or brass, the pulley 37 of sufficient quality is formed because the pulley 37 has excellent processing accuracy, rigidity, and conductivity. be able to. However, cutting is expensive and it is difficult to form an inexpensive pulley 37.

On the other hand, the one in which the central boss portion is formed by using a sintered member and the conductive resin pulley is fitted on the outer peripheral portion is inexpensive, but it is difficult to obtain the precision of the component, and the component component If the precision is not further increased, the pulley 37 will swing and the wow and flutter characteristics will deteriorate. The conductive resin applied to the outer periphery of the boss is mixed with a conductive agent such as carbon in order to increase the conductivity, but if such a conductive agent is mixed, the hardness of the pulley increases, Since the boss member is also made of a sintered material, there are variations in outer diameter accuracy, and the pulley easily cracks when the pulley is press-fitted. Easy to crack. Therefore, such pulleys are not of sufficient quality.

The present invention has been made to solve the above problems, and an object thereof is to provide a motor pulley that is inexpensive and excellent in accuracy, rigidity, and conductivity.

[0008]

Means for Solving the Problems The present invention includes a pulley that is fixed to a rotor portion facing a stator portion and rotates integrally with a rotation shaft, and a pulley of a motor that drives a belt by the pulley has two pulleys. It is characterized in that it is composed of two members, and at least one of them is a plate made by pressing a metal plate.

[0009]

[Action]

 At least one of the two members forming the pulley is a plate-shaped metal plate, and the peripheral groove is formed with the other member forming the pulley. The belt can be driven by mounting the belt on the circumferential groove and rotating the pulley together with the rotor.

[0010]

【Example】

 An embodiment of a motor pulley according to the present invention will be described below with reference to the drawings. 1 to 3, the central portion of the metallic rotor case 4 is a protruding portion 4d protruding upward in a pyramid shape, and a cylindrical boss portion 4c is formed at the center of the protruding portion 4d. Has been done. The rotary shaft 2 is press-fitted in the center of the boss portion 4c, and the rotary shaft 2 and the rotor case 4 are integrated. A plurality of through holes 4a are formed on the protrusion 4d around the boss 4c. The protrusion 4d forms a lower member of the pulley.

An upper member 5 of a pulley formed in a dish shape is attached to an upper portion of the protruding portion 4d of the rotor case 4. The central portion of the upper member 5 is a protruding portion 5d protruding downward in a conical shape, and the portion other than the protruding portion 5d is a flat flange portion 5c. A through hole is formed at the center of the protruding portion 5d, and the boss portion 4c of the rotor case 4 is inserted inside the through hole. A plurality of convex portions 5a corresponding to the through holes 4a of the rotor case 4 are formed around the through holes on the lower surface of the projecting portion 5d, and the respective convex portions 5a are press-fitted into the through holes 4a. .

By attaching and fixing the upper member 5 to the protruding portion 4d of the rotor case 4, the two members of the rotor case 4 and the upper member 5 form a pulley of the motor. The outer periphery of the pulley is a peripheral groove 3 having a cross-sectional angular shape due to the oblique portions of the protruding portions 5d and the protruding portions 4d which are present above and below, and the angular belt 20 is attached to the peripheral groove 3. Can be hung. The belt 20 hung on the circumferential groove 3 of the pulley has two inner surfaces that are adjacent to each other across the inner corner and are in contact with the conical surfaces of the protrusions 4d and 5d that form the circumferential groove 3. . In the circumferential groove 3, a gap 6 is formed outside the portion where the surfaces of the protruding portion 5d and the protruding portion 4d are in contact with each other in order to allow the corner portion of the belt 20 to escape inside. When the rotary shaft 2 rotates, the pulley constituted by the upper member 5 and the rotor case 4 which are integral with the rotary shaft also rotates, and the belt 20 hung on the circumferential groove 3 of the pulley is driven accordingly.

The above-mentioned motor pulley is formed by the following procedure. A flat metal plate is punched by a general-purpose press machine or the like to form a flat circular upper member 5. The upper member 5 is perforated or coated as necessary. The central portion of the upper member 5 is pressed to form a protruding portion 5d protruding downward. Pressing is performed from the bottom surface side of the protrusion 5d to form a plurality of protrusions 5a on the lower surface side of the protrusion 5d. A through hole is formed by punching the center of the protrusion 5d with a press. The protrusion 5a of the upper member 5 is fixed by press-fitting or caulking it into the through hole 4a in the upper surface of the rotor case 4 made of metal, and the pulley of the motor is completed.

Since the upper member 5 and the rotor case 4 forming the pulley are both made of metal, the pulley of the motor having the above-described structure has good conductivity, and static electricity is not generated by friction with the belt 20. , Even if it occurs in the example, you can dissipate static electricity. Therefore, dust or the like scattered in the air is not adsorbed on the pulley or the belt. Since the upper member 5 can be formed by a general-purpose press working machine, it can be formed accurately even at low cost. Since the upper member 5 is made of metal, sufficient strength can be ensured, and a pulley of a good quality motor without cracks can be formed. Moreover, since the upper member 5 is a pressed part, the contact resistance can be increased or decreased by post-treatment, and one part can be used for general purposes.

Next, another example of the motor pulley will be described. In FIG. 4, a central portion of the metallic rotor case 14 is a protrusion 14d, and a cylindrical boss portion 14c is formed at the center of the protrusion 14d. The rotary shaft 12 is press-fitted in the center of the boss portion 14c, and the rotor case 14 and the rotary shaft 12 are integrated. A plurality of through holes 14a are formed on the protruding portion 14d around the boss portion 14c. An upper member 15 and a lower member 16 formed in a dish shape are attached to the upper portion of the protruding portion 14d of the rotor case 14. The two upper members 15 and the lower member 16 are stacked so that the cross-sectional shape is a lateral X-shape to form a motor pulley.

The upper member 15 forming the upper half of the pulley has a protruding portion 15d protruding downward in a conical shape, and a portion other than the protruding portion 15d is a flat flange portion 15c. A through hole is formed in the central surface of the protruding portion 15d, and the boss portion 14c of the rotor case 14 is inserted into this through hole. On the lower surface of the protrusion 15d, a plurality of protrusions 15a corresponding to the recesses 16b formed in the lower member 16 described later are formed.

The lower member 16 constituting the lower half of the pulley has a protruding portion 16d protruding upward in a conical shape, and a portion other than the protruding portion 16d is a flat flange portion 16c. A through hole is formed in the center surface of the protruding portion 16d, and this through hole is connected to the through hole of the upper member 15, and like the upper member 15, the boss portion 14c of the rotor case 14 is inserted. There is. A plurality of concave portions 16b are formed in a circular shape on the plane portion of the protrusion 16d with the rotating shaft 12 as the center. The opposite side of the concave portion 16b is a convex portion 16a protruding downward as shown in FIG. In FIG. 4, the concave portion 16b of the lower member 16 corresponds to the convex portion 15a of the upper member 15 described above, and the convex portion 15a is inserted into the concave portion 16b by a method such as press fitting, caulking, or spotting. The convex portion 16a on the opposite side of the concave portion 16b is fixed in the through hole 14a formed in the rotor case 14 by a method such as press fitting or caulking.

Next, a procedure for forming the pulley of the motor as described above will be described. As shown in FIGS. 6 and 7, a flat metal plate 21 is pressed, and a downward projection 22 that becomes the upper half of the pulley in the subsequent step and the lower half of the pulley in the latter step are formed on the same plate. The upward projections 23 are alternately formed. A plurality of protrusions are formed by pressing the mold against the bottom surfaces of the protrusions 22 and 23 formed in the same metal plate in opposite directions. The protrusion 22 in the upper half of the pulley has a protrusion in the same direction as the protrusion direction, and the protrusion 23 in the lower half of the pulley has a protrusion in the opposite direction to the protrusion direction. Further, a through hole is formed in the central portion of the bottom surface of these two protrusions 22, 23. Of the protrusions 22 and 23 processed as described above, the protrusion 23, which is the lower half of the pulley, is punched out to form the lower member 16, and the lower member 16 is held below the plate 21. After that, the protrusion 22 is punched out to become the upper member 15, and the upper member 15 is the upper portion of the lower member 16 held below, as shown in FIG. 8, and the convex portion 15a faces the concave portion 16b of the lower member 16. Are superposed in this way. The upper member 15 and the lower member 16 that are overlapped with each other are pressed to fix the convex portion 15a into the concave portion 16b, thereby forming a pulley of the motor. After that, the pulley of the motor is attached to the upper part of the rotor by press-fitting the convex portion 16a formed on the lower member 16 into the through hole 14a formed on the rotor case 14.

Since the rotor of the motor having the above-described structure is also made of metal as in the above-described embodiment, it has good conductivity and does not generate static electricity due to friction with the belt. Can be missed. Therefore, dust and the like scattered in the air will not be adsorbed. Further, since the upper member 15 and the lower member 16 which form the pulley are formed by a general-purpose press machine, they can be formed at low cost and with high accuracy. In addition, since it is made of metal, it has sufficient strength, is unlikely to cause cracks, etc., and does not cause variations in the shape after formation, which is good in quality. Further, since the upper members 15 and 16 constituting the pulley are press parts, the contact resistance can be increased or decreased by post-treatment, and the parts can be used for general purposes.

As shown in FIG. 9, the diameter d1 of the rising start position of the conical protruding surface of the upper member 15 constituting the upper half of the pulley is set to the conical protruding surface of the lower member 16 constituting the lower half of the pulley. If the diameter is larger than the diameter d2 at the falling start position of the belt, the difference between the diameters d1 and d2 can be used as a gap for escaping the corner of the belt, so a gap for escaping the corner is formed. It is not necessary and leads to further cost reduction. The relationship between d1 and d2 may be reversed such that d1 <d2.

The pulley of the motor according to the present invention is not limited to a capstan motor such as a video tape recorder, but is effective for AV (audio and visual) equipment and equipment that requires conductivity for the pulley. Is.

In each of the embodiments described above, the rotary shaft has a shape penetrating the lower member and the upper member of the pulley. However, as shown in FIG. 10, the rotary shaft penetrates the central hole of the lower member 27 of the pulley. The tip end of the rotary shaft 28 of the motor press-fitted may be brought into contact with the central portion of the upper member 26 of the pulley.

[0023]

[Effect of device]

 According to the present invention, the pulley is composed of two members, and at least one of these members is a metal plate formed into a plate shape by pressing, so that it is inexpensive and excellent in accuracy, rigidity, and conductivity. It is possible to provide a pulley of a motor. Moreover, it is highly versatile because it can increase or decrease the contact resistance by post-treatment.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a pulley of a motor according to the present invention.

FIG. 2 is an exploded perspective view of the same as above.

FIG. 3 is a perspective view of the same.

FIG. 4 is a sectional view showing another embodiment of the pulley of the motor according to the present invention.

FIG. 5 is an enlarged sectional view showing a main part of a pulley of the same motor.

FIG. 6 is a plan view showing an example immediately after punching in the pulley of the same motor.

FIG. 7 is a sectional view of the same.

FIG. 8 is an exploded cross-sectional view showing another embodiment of the same motor pulley.

FIG. 9 is an enlarged sectional view of an essential part showing still another example of the pulley of the motor according to the present invention.

FIG. 10 is an enlarged sectional view of an essential part showing still another example of the pulley of the motor according to the present invention.

FIG. 11 is a cross-sectional view showing an example of a conventional motor pulley.

[Explanation of symbols]

 4 14 rotor part 2 12 rotating shaft 20 belt

Claims (1)

[Scope of utility model registration request] 1. A pulley of a motor, comprising a pulley fixed to a rotor portion facing a stator portion and rotating integrally with a rotating shaft, wherein the pulley drives a belt. The pulley is composed of two members. A pulley for a motor, wherein at least one of the members is a plate formed by pressing a metal plate.