JPS6237003Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a thrust force applying device for a rotating shaft that is most suitable for application to guide shafts, capstans, etc. of various recording and reproducing devices, for example.

[Background technology and its problems]

BACKGROUND ART In various recording and reproducing devices, there are devices in which a guide shaft, a capstan, etc. are arranged horizontally.
Unlike the vertical rotation shafts, which are always thrust downward by gravity, these horizontal rotation shafts must be thrust-energized by some method. Conventionally, the following methods have been adopted for this purpose. First, a thrust receiver consisting of a thrust screw or a thrust spring provided on the chassis is brought into contact with both ends of the rotating shaft. However, with this method, the frictional resistance of the rotating shaft increases depending on the tightening of the screws and the strength of the spring, and the rotating shaft becomes unstable, making the thrust force unstable. It had the disadvantage that it was extremely troublesome and took a lot of time to assemble. When a thrust bearing cannot be provided at one end of a capstan or the like, a flange or the like is provided on the capstan shaft, and this flange is brought into contact with the side surface of the bearing via a polywasher or the like. In addition to the above-mentioned drawbacks, this method also has the disadvantage that the frictional resistance at the contact surface is extremely large and that wow and flutter increase due to uneven rotation.

[Purpose of invention]

The present invention aims to provide a thrust force energizing device for a rotating shaft that can correct the above-mentioned drawbacks.

[Summary of the idea]

The present invention includes a first pulley fixed to a rotating shaft;
A second pulley fixed to the drive shaft is arranged at a twisted position substantially perpendicular to the rotation axis, and an elastic belt is wound between the first and second pulleys. , the winding side of the belt from the second pulley to the first pulley is perpendicular to the axial direction of the rotating shaft, and the winding side of the belt from the first pulley to the second pulley is as described above. The belt is tilted at a predetermined angle with respect to the axial direction of the rotating shaft, and the first
A thrust force is applied to the rotating shaft by a component of the pulling force of the pulley to thrust the rotating shaft in one direction in the axial direction, and a thrust receiver is provided at one end of the rotating shaft to receive the thrust force. This is a thrust force energizing device for a rotating shaft, which can always obtain a constant thrust force as the rotating shaft rotates, and can extremely stably apply thrust to the thrust receiving side of the rotating shaft. Additionally, since no special parts are required for thrust energization, assembly is extremely easy due to the reduced number of parts, and there is no need for any troublesome adjustments.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

First, FIGS. 1 to 6 show a first embodiment in which the present invention is applied to a magnetic disk recording/reproducing apparatus. First, as shown in FIGS. 1 to 3, a motor 3 is provided on a chassis 2 of a main body 1 of a magnetic disk recording/reproducing apparatus. This motor 3 directly rotates a magnetic disk 4 shown in phantom lines in FIG. 1, and has a rotating table 6 fixedly attached to its drive shaft 5. Note that 7 and 8 are a rotation drive pin and a ring-shaped magnet provided on the rotary table 6, respectively.

Next, the chassis 2 is provided with a head moving table 10. As shown in FIG. 4, this head moving table 10 consists of a bobbin 11 at the center, a head support section 12 at the front, and a bearing section 13 at the rear. The bobbin 11 has a hollow flat shape, and a coil 14 is formed on the outer periphery.
Further, a magnetic head 15 is fixed to the head support portion 12. Further, the bearing portion 13 is provided with a pair of bearings 16a and 16b. Note that metal bearings, oil-impregnated bearings, or the like are used for these bearings 16a and 16b. The head support portion 12 and the bearing portion 13 are connected to the left and right flanges 11 of the bobbin 11.
It is fixed to the portions a and 11b with screws or the like. As shown in FIGS. 1 and 2, the head moving table 10 is guided by a guide shaft 18 inserted through bearings 16a and 16b so as to be able to reciprocate, and the magnetic head 15 is moved by a motor. It is configured to reciprocate in the radial direction of the drive shaft 5 of No. 3.

Next, the guide shaft 18 is moved by bearings 20a, 20b provided on a pair of support parts 19a, 19b integrally formed with the chassis 2, as shown in detail in FIGS. 1, 2, and 5. It is rotatable around its axis and is also supported slidably in its axial direction. Note that these bearings 20a, 20
A metal bearing or the like is used for b. A first pulley 21 is fixed to one end 18a of the guide shaft 18, and the other end 18b is processed into a spherical shape and abuts a thrust receiver 23 screwed into a support portion 22 formed integrally with the chassis 2. being touched.

However, this guide shaft 18 is a rotating shaft in the present invention, and is configured to be constantly rotated by the motor 3. That is, as shown in FIGS. 1 to 3, a second pulley 24 is fixed to the drive shaft 5 of the motor 3 at a lower position of the rotary table 6. As shown in FIGS. Note that the guide shaft 18 and the drive shaft 5 of the motor 3 are arranged in twisted positions that are substantially perpendicular to each other. And the first pulley 2 of the guide shaft 18
A belt 25 made of an elastic rectangular belt is wound between the drive shaft 1 and the second pulley 24 of the drive shaft 5. By the way, as shown in FIG. 5, this belt 25 has a winding side 25a from the second pulley 24 to the first pulley 21 at right angles to the axial direction of the guide shaft 18, and a winding side 25a from the first pulley 21 to the second pulley 2.
The unwinding side 25b to 4 is inclined at a predetermined angle θ with respect to the axial direction of the guide shaft 18. The unwinding side 25b is wound around the second pulley 24 at right angles to the axial direction of the drive shaft 5.

Next, as shown in FIGS. 2 and 6, the head moving table 10 constitutes a part of a linear motor, and the head moving table 10 is moved by this linear motor.
is reciprocated. That is, three flat yokes 27, 28, 29 are arranged on the chassis 2, with a pair of magnets 30a, 30b and 31a, 31b sandwiched therebetween. The head moving table 10 is configured to reciprocate between the yokes 27, 28 and 28, 29, with the central yoke 28 inserted into the hollow portion 11c of the bobbin 11 in which the coil 14 is formed. ing. The head support portion 12 of the head moving table 10 is supported from below by a freely rolling steel ball 33 within a groove 32 provided in the chassis 2. The head moving table 10 is reciprocated in parallel with the chassis 2 by the guide shaft 18 and steel balls 33.

According to the magnetic disk recording and reproducing apparatus configured as described above, first, the motor 3 is rotated in the direction of arrow a in FIG. 1, and the magnetic disk 4 is rotationally driven. The head movable base 10 is reciprocated by a current flowing through a coil 14 formed in the bobbin 11 of the head movable base 10, so that the magnetic head 15 performs desired recording or reproduction.

When the motor 3 is rotated, the belt 25
The guide shaft 18 is rotated at high speed. Since the guide shaft 18 is rotated at high speed, the frictional resistance between the guide shaft 18 and the bearings 16a, 16b of the head moving table 10 is extremely small. That is, when the guide shaft 18 is rotated at high speed, the bearings 16a,
If a metal bearing is used for 16b, bearing 1
A negative pressure is generated between the inner circumferential surfaces of the guide shafts 6a and 16b and the guide shaft 18, and an air film is formed. Further, when oil-impregnated bearings are used as the bearings 16a and 16b, the oil impregnated in the oil-impregnated bearings oozes out due to the same negative pressure as described above, and an oil film is formed. As a result, the bearings 16a, 16b are lifted from the guide shaft 18, and the bearings 16a, 16b and the guide shaft 18 are lifted up.
8 will be drastically reduced. Therefore, the driving force required to slide the head moving table 10 is extremely small. Also, bearings 16a, 1
6b and the guide shaft 18 are always in a state of dynamic frictional resistance, so there is no nonlinear change in frictional resistance when the head moving table 10 is slid. That is, since there is no sudden change from static frictional resistance to dynamic frictional resistance when the head moving table 10 is slid from a stationary state, position servo of the head moving table 10 is extremely easy to apply. Therefore, minute movement of the head moving table 10 from a stationary state and accurate position control can be performed extremely easily.

Next, as the guide shaft 18 is rotated, the guide shaft 18 is always thrust in one axial direction, that is, in the direction of the arrow b in Fig. 5. That is, the winding side 25a of the belt 25 from the second pulley 24 to the first pulley 21 is perpendicular to the axial direction of the guide shaft 18, and the unwinding side 25b of the belt 25 from the first pulley 21 to the second pulley 24 is inclined at a predetermined angle θ to the axial direction of the guide shaft 18. Therefore, when the belt 25 is driven to rotate, the belt 25 contacts the contact portion 2 of the first pulley 21 as shown in Fig. 3.
In the pulley 1a, a gripping action occurs in the inclined direction in the range of 180°-α (α varies depending on the pulley diameter, inclination angle, etc.). As shown in FIG. 5, the pulling force P
is resolved into a rotational force _P1 of the first pulley 21, i.e., the guide shaft 18, and a thrust force _P2 of the guide shaft 18. As a result, when the guide shaft 18 is rotated, it is always thrust in one direction of the axial line, that is, the direction of the arrow b. This thrust force is always constant as the guide shaft 18 rotates, and the guide shaft 18 is supported by the thrust bearing 29 in an extremely stable manner.
In addition, since no special parts are required for thrust application,
The reduced number of parts makes assembly easy and eliminates the need for any troublesome adjustments.

Next, FIGS. 7 and 8 show a second embodiment in which the present invention is applied to a magnetic tape recording/reproducing apparatus.

Capstan 3 of this magnetic tape recording/reproducing device
7 is arranged horizontally, and chassis 3
It is supported by a bearing 39 provided at 8 so as to be rotatable around its axis and also slidable in its axial direction. Then, the magnetic tape 40 is attached to the pinch roller 4 on the tip 37a side of the capstan 37.
1. Further, the base end 37b of the capstan 37 is in contact with a thrust receiver 43 provided on a support portion 42 integral with the chassis 38. Note that this capstan 37 is the rotating shaft in the present invention. And the capstan 37 has the first pulley 4.
4 is integrally formed with a large diameter flywheel 45.
is fixed.

On the other hand, the chassis 38 is provided with a motor 46, and a second pulley 48 is fixed to a drive shaft 47 of the motor 46. Furthermore, the capstan 37 and motor 46
and the drive shaft 47 are arranged in twisted positions substantially perpendicular to each other. And the first of Capstan 37
Between the pulley 44 and the second pulley 48 of the drive shaft 47 is a belt 49 made of an elastic square belt.
is wrapped around it. By the way, this belt 49
The winding side 49a from the second pulley 48 to the first pulley 44 is perpendicular to the axial direction of the capstan 37, and the winding side 49a from the first pulley 44 to the second pulley 48 is made perpendicular to the axial direction of the capstan 37.
The unwinding side 49b is inclined at a predetermined angle θ' with respect to the axial direction of the capstan 37. Note that the unwinding side 49b is wound around the second pulley 48 at right angles to the axial direction of the drive shaft 47.

According to the magnetic tape recording and reproducing apparatus constructed as described above, when the motor 46 is rotated in the direction of the arrow α' in FIG. 7, the capstan 37 is rotated by the belt 49. Therefore, the unwinding side 49 of the belt 49 from the first pulley 44 to the second pulley 48
By tilting b at a predetermined angle θ' with respect to the axial direction of the capstan 37, the belt 49 is tilted within a range of 180°-α' (α ′ changes depending on the pulley diameter, inclination angle, etc.), and a biting action occurs in the inclined direction. As shown in FIG. 7, the tensile force P' exerted by the unwinding side 25b of the belt 49 is divided into a rotational force P' ₁ of the first pulley 44, that is, the capstan 37, and a thrust force P' ₂ of the capstan 37. Decomposed. As a result, when the capstan 37 is rotated, it is always thrust-energized in the direction of arrow b', which is one direction along the side line. This thrust force is always constant as the capstan 37 rotates, and the thrust force of the capstan 37 can be extremely stably applied to the thrust receiver 43 side. In particular, even when the tip end 37a side of the capstan 37 cannot be used for thrust energization, the thrust direction can be restricted only on the base end 37b side. Therefore, the frictional resistance is small, and no wow or flutter occurs due to uneven rotation.

Note that although the rotating shafts shown in the embodiments are all arranged horizontally, the arrangement of the rotating shafts is not limited to being horizontal, but may be arranged vertically to provide more stable thrust energization. Thrust energization is also possible with other arrangements.

[Application example]

Although the embodiments of the present invention have been described above, the present invention is not limited to the recording/reproducing apparatus shown in the embodiments, but can be applied as a thrust force energizing device for a rotating shaft in various types of equipment.

[Effects of the invention] As described above, the present invention has a first pulley fixed to the rotating shaft, and a second pulley fixed to the drive shaft arranged at a twisted position substantially perpendicular to the rotating shaft. and an elastic belt wound between the first and second pulleys, the winding side of the belt from the second pulley to the first pulley being oriented in the axial direction of the rotating shaft. the unwinding side of the belt from the first pulley to the second pulley is inclined at a predetermined angle with respect to the axial direction of the rotating shaft, and the belt on the unwinding side A thrust force is applied to the rotating shaft by a component of the tensile force to thrust the rotating shaft in one direction in the axial direction, and a thrust receiver is provided at one end of the rotating shaft to receive the thrust force. This is a shaft thrust force energizing device. According to the present invention, the rotating shaft can always obtain a constant thrust force as it rotates, and the rotating shaft can be extremely stably thrust-energized toward the thrust receiving side. Additionally, since no special parts are required for thrust energization, assembly is extremely easy due to the reduced number of parts, and there is no need for any troublesome adjustments.

[Brief explanation of the drawing]

1 to 6 show a first embodiment in which the present invention is applied to a magnetic disk recording/reproducing device, in which FIG. 1 is a plan view of the main body of the device, FIG. 2 is a perspective view of the main parts, FIG. 3 is an enlarged side view of FIG. 1 as viewed from the - line, FIG. 4 is an exploded perspective view of the head moving table,
FIG. 5 is an enlarged plan view showing a guide shaft and related parts in cross section, and FIG. 6 is an enlarged sectional view taken along the line - in FIG. 7 and 8 show a second embodiment in which the present invention is applied to a magnetic tape recording/reproducing device, in which FIG. 7 is a plan view of the main part, and FIG.
The figure is a front view. In addition, in the symbols used in the drawings, 3...Motor, 5...Drive shaft, 18...Guide shaft which is a rotating shaft, 21...First pulley, 23...Thrust receiver, 24...Second pulley, 25...Belt, 25
a... winding side, 25b... unwinding side.

Claims (1)

[Scope of utility model registration request] a first pulley fixed to the rotating shaft; a second pulley fixed to the drive shaft disposed at a torsion position substantially perpendicular to the rotating shaft; and the first and second pulleys.
an elastic belt wound between pulleys, the winding side of the belt from the second pulley to the first pulley is perpendicular to the axial direction of the rotating shaft, and The unwinding side of the belt from the first pulley to the second pulley is inclined at a predetermined angle with respect to the axial direction of the rotating shaft, and a component of the pulling force of the belt on the unwinding side of the first pulley is applied. A thrust force applying device for a rotating shaft, which applies a thrust force to the rotating shaft to thrust the rotating shaft in one direction in the axial direction, and includes a thrust receiver provided at one end of the rotating shaft to receive the thrust force. .