JPH09149587A - motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent oil from entering the part which is brought into contact with the tape-like recording medium of a shaft by applying an oil repellent treatment between the part which is brought into contact with the tape-like recording medium of a shaft and an oil retaining bearing. SOLUTION: Volatile treatment parts 190, 190 are applied to the regions 170, 180 between the part 150 brought into contact with a video tape and two oil retaining bearings 114, 115, respectively. The volatile treatment parts 190, 190 can be formed by applying a material to repel the oil which is contained in the oil retaining bearings 114, 115, for instance, a solution or the like such as a fluorine series solution. Therefore, even when the oil leaked from the oil retaining bearings 114, 115 leaks on the part 150 side which is brought into contact with the video tape, the two volatile treatment parts 190, 190 repel the respective oil, so that the oil of the oil retaining bearings may be completely prevented from reaching the part 150 brought into contact with the video tape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor such as a capstan motor which is optimal for use in a video tape recorder (VTR) or the like.

[0002]

2. Description of the Related Art As an apparatus using a tape-shaped recording medium, there is a video tape recorder. This video tape recorder has a capstan motor for feeding a magnetic tape. The capstan motor has a capstan shaft that transmits the driving force of the motor to the magnetic tape, and the capstan shaft causes the tape-shaped recording medium to move in a predetermined direction by friction with the tape-shaped recording medium together with the capstan roller. It is designed to be pulled and sent to. FIG. 2 shows a conventional capstan motor. The capstan shaft 1 of the capstan motor is rotatably supported by oil-impregnated bearings 2 and 2.

[0003]

However, the oil-impregnated bearing 2
As shown by the arrow T, oil oozes out,
It is transmitted in the axial direction of the capstan shaft 1. That is,
Oil adheres to the portion (tape running portion) 1a where the capstan shaft 1 contacts the tape-shaped recording medium. As a result, not only the oil adheres to the tape-shaped recording medium, but also the adhered oil adversely affects the running system of the tape-shaped recording medium. Therefore, as shown in the conventional capstan motor of FIG. 3, washers 3, 3 are provided at both end portions of the portion 1a of the capstan shaft 1 which is in contact with the tape-shaped recording medium.
There is an attempt to prevent the oil from the oil-impregnated bearings 2 and 2 from entering the portion 1a in contact with the tape-shaped recording medium by press-fitting.

However, even if a labyrinth structure is formed by press-fitting and mounting the washers 3 and 3 onto the capstan shaft 1, the oil leaking from the oil-impregnated bearing 2 gets over the washer 3 and forms a tape-like shape as shown by an arrow S. The oil leaking from the oil-impregnated bearing 2 passes through between the washer 3 and the capstan shaft 1 as shown by the arrow U and reaches the portion 1a in contact with the tape-shaped recording medium. There is a drawback that it will penetrate, it is not possible to completely prevent oil from entering, and furthermore, the washer 3,
Since 3 is required, there is a drawback that the number of parts increases. Therefore, the present invention has been made to solve the above problems, and a motor capable of preventing oil leaking from an oil-impregnated bearing from infiltrating into a portion in contact with a tape-shaped recording medium without increasing the number of parts. Is intended to provide.

[0005]

According to the present invention, there is provided a motor in which a shaft for feeding a tape-shaped recording medium by using a frictional force is rotatably supported via an oil-impregnated bearing. This is achieved by a motor that is oil-repellent treated between the portion of the shaft that contacts the tape-shaped recording medium and the oil-impregnated bearing. In the present invention, the oil repellent treatment is applied between the portion of the shaft that contacts the tape-shaped recording medium and the oil-impregnated bearing. As a result, the oil that leaks from the oil-impregnated bearing is repelled at the oil-repellent portion, so that the oil does not enter the portion of the shaft that contacts the tape-shaped recording medium. Moreover, since the oil repellent treatment is only applied to the shaft, the number of parts does not increase.

[0006]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are preferred specific examples of the present invention,
Although various technically preferable limitations are given, the scope of the present invention is not limited to these modes unless otherwise specified to limit the present invention. FIG. 1 shows a capstan motor for a video tape recorder (VTR) which is a preferred embodiment of the motor of the present invention. In FIG. 1, this motor is used to convey a video tape, and conveys the video tape by friction together with a capstan roller (not shown). A rotor (rotor) R of this capstan motor has a boss 102, a rotor yoke 108, a resin magnet 109, a rotor magnet 112, a capstan shaft 110, and the like.

The rotor yoke 108 is fixed to the boss 102 by caulking, and is made of a magnetic material such as a galvanized steel plate in order to serve also as a back yoke of the rotor magnet 112. Resin magnet (FG
The magnet) 109 is also called a frequency generating magnet or a frequency generating magnet, and is a rotor yoke 108.
It is arranged on the outer peripheral portion by adhesion or integral molding. The resin magnet 109 is made of, for example, polyamide (nylon) or polyphenylene sulfide (PPS).
It is a magnet based on resin such as. The resin magnet 109 is a magnet in which N-poles and S-poles are alternately magnetized on the peripheral surface in multiple pitches at equal pitches. The rotor magnet 112 is a magnet for driving the rotor R, and is fixed to the inner surface of the rotor yoke 108 by adhesion or the like. The rotor magnet 112 is magnetized to have N poles and S poles alternately in multiple poles.

Next, the stator (stator) S has a motor substrate 101, a coil 107, a housing 113 and the like. The housing 113 rotatably supports one end and the other end of the capstan shaft 110 with oil-impregnated bearings 114 and 115. The other end of the capstan shaft 110 is supported by a thrust receiver 116 in the thrust direction. One end of the capstan shaft 110 is fixed to the boss 102 by press fitting. The housing 113 is fastened or fixed to the motor board 101 by screws, caulking, or adhesion. On the motor board 101 of the stator S, a connector, a speed detection element, a driving IC, chip parts such as resistors and capacitors,
A plurality of coils 107 for driving are attached.

The oil-impregnated bearings 114, 115 described above are cylindrical slide bearings, and are made of a porous material, for example, a metal containing copper as a main component. The oil-impregnated metal portion of the cylindrical oil-impregnated bearings 114, 115 contains a predetermined content of oil. As this oil, for example, machine oil can be adopted. The capstan shaft 110 is a portion that is in contact with the video tape (also called a tape running portion) 15
It has 0. The part that contacts this video tape 150
Therefore, it is necessary to prevent the oil of the oil-impregnated bearings 114 and 115 from adhering. This is because it is necessary to prevent oil from adhering to the video tape and prevent the oil from adhering to the drive of the running system of the video tape.

Therefore, in the embodiment of the present invention, the portion 150 in contact with the video tape and the two oil-impregnated bearings 114, 1 are provided.
Regions 170 and 180 between 15 are provided with oil repellent treated portions 190 and 190, respectively. The oil-repellent treated portions 190, 190 can be formed by applying a material that repels the oil contained in the oil-impregnated bearings 114, 115, for example, a solution such as a fluorine-based solution.

By doing so, the oil-impregnated bearing 114,
Oil leaking from 115 contacts the video tape 15
Even when it tries to leak to the 0 side, the two oil-repellent treated portions 190, 190 repel those oils, so that the oil of the oil-impregnated bearing completely reaches the portion 150 in contact with the video tape. You can This motor is connected to each coil 1 from a drive circuit (not shown) through a connector.
Current is sequentially supplied to 07 in a predetermined energization pattern. Thereby, each coil 107 generates a magnetic field, and the magnetic field causes the rotor R including the rotor magnet 112 to rotate with respect to the stator S. This rotor R
When rotating, the capstan shaft 110 is rotatably supported by the bearings 114 and 115 of the housing 113 of the stator S. Since the resin magnet 109 is rotated by the rotation of the rotor R, the N pole and the S pole alternately pass through the sensing surface of the speed detecting element. Therefore, the speed detecting element can convert a change in the magnetic flux of the resin magnet 109, which has N and S poles alternately magnetized, into an electric signal for detecting the motor speed.

As the rotor R rotates with respect to the stator S in this manner, the portion 150 of the capstan shaft 110 that contacts the video tape sandwiches the video tape together with a capstan roller (not shown), and the video tape is rubbed by a predetermined amount. Send in the direction. In this case, the oil-impregnated bearing 11
Even if oil leaks from 4,115, the oil-repellent treated portion 19
Since 0 repels the leaked oil, it will not penetrate into the portion 150 where it contacts the video tape. As a result, the oil does not adhere to the video tape to be contaminated and the oil does not adhere to the video tape, so that the oil does not adversely affect the tape running system. Since it is not necessary to use a washer as in the conventional case, the number of parts can be reduced. In the embodiment of the present invention, the entire housing 113 or the oil-impregnated bearing 11 is used.
Oil repellent treatment may be applied to the regions supporting 4,115. The oil repellent treatment is performed, for example, by applying an oil repellent solution.

The present invention is not limited to the above embodiment. In the embodiment described above, the capstan shaft 11
Zero is rotatably supported by two oil-impregnated bearings 114 and 115. However, not limited to this, the capstan shaft 1
10 can be supported by one oil-impregnated bearing and the other, for example, a ball bearing. In this case,
In the capstan shaft 110, the oil-repellent treated portion 1 is provided only between the one oil-impregnated bearing and the portion 150 in contact with the video tape.
It is enough to form 90. The oil repellent treatment is not limited to the case of applying the oil repellent solution, and other treatment methods are possible. The capstan motor according to the embodiment of the present invention is applied to a video tape recorder, but the present invention is not limited to this, and can be applied to other devices such as a digital audio tape recorder (DAT). Further, the motor of the present invention can be applied to a motor for transportation other than the capstan motor.

[0014]

As described above, according to the present invention,
It is possible to prevent the oil leaking from the oil-impregnated bearing from entering the portion in contact with the tape-shaped recording medium without increasing the number of parts.

[Brief description of the drawings]

FIG. 1 is an axial cross-sectional view showing a capstan motor according to an embodiment of the present invention.

FIG. 2 is an axial sectional view showing a conventional capstan motor.

FIG. 3 is an axial sectional view showing another conventional capstan motor.

[Explanation of symbols]

 110 Capstan Shaft (Shaft) 113 Housing (Housing Member) 114, 115 Oil Bearing 150

Claims (4)

[Claims] 1. A motor for rotatably supporting a shaft for feeding a tape-shaped recording medium using frictional force via an oil-impregnated bearing, a portion of the shaft contacting the tape-shaped recording medium, and an oil-impregnated bearing. An oil repellent treatment is applied between the motors. 2. The one end of the shaft is supported by a first oil-impregnated bearing arranged in the housing member, and the other end of the shaft is supported by a second oil-impregnated bearing arranged in the housing member. The motor described in. 3. The motor according to claim 2, wherein the housing member is also oil-repellent treated. 4. The motor according to claim 1, wherein the oil repellent treatment is performed by applying an oil repellent solution.