JPS6298061A - Rotation transmission mechanism - Google Patents

Abstract

PURPOSE:To reduce a loss in the torque of a rotary shaft, by applying a side pressure to a motor shaft, which acts in the direction opposite to the direction of a side pressure applied by a transmitting member. CONSTITUTION:The rotating center of a counter pulley 15 is located at a position opposite to the direction of a tension P1 applied to a pulley 12 by a transmission belt 14, across a rotary shaft 9 positioned therebetween. The diameter of the counter pulley 15 is relatively larger than that of a pulley 13 of a pulley body 11. Further, a counter belt 17 is stretched between the pulley 13 of the pulley body 11 and the counter pulley 15. Accordingly, it is possible to reduce a loss in torque due to a side pressure exerted to the rotary shaft.

Description

[Detailed Description of the Invention] The rotation transmission mechanism of the present invention will be explained according to the following items - A. Field of industrial application B6 Overview of the invention C0 Prior art [Figures 7 and 8] D9 Problems to be solved by the invention Problems [Figures 7 and 8] E9 Means for solving problem F, Example F-1, First example [Figures 1 and 2] a, Configuration, Counter belt Tension on the rotating shaft and its effect C, Advantages of providing a counter belt c-1, General formula % formula % F-2, Second embodiment [Figure 3, Figure 4 Core a, Configuration, Idler Effects of the tire C, Advantages of providing an idler tire F-3, Third embodiment [Figures 5 and 6] G1 Effects of the invention (A, Industrial application field) The present invention provides a novel rotational Regarding the transmission mechanism. Specifically, it relates to a rotation transmission mechanism that transmits the rotational force of a motor to a capstan in a video tape recorder, an audio tape recorder, etc. via a transmission member such as a transmission belt or a rotating tire. It is an object of the present invention to provide a novel rotation transmission mechanism that can reduce the rotational force loss of the rotating shaft caused by the side pressure applied by the transmission member by relatively simple means.

(B. Summary of the Invention) The present invention transmits the rotational force of a motor to a transmission member such as a transmission belt wound around an output pulley fixed to the rotation shaft of the motor or a rotating tire rotated in contact with the rotation shaft. In a rotation transmission mechanism that transmits the rotation to a predetermined rotated member via This is designed to reduce the loss of rotational force of the rotating shaft due to the transmission member.

(C9 Prior Art) [Figures 7 and 8] For example, in a tape recorder such as a video tape recorder or an audio tape recorder, a magnetic tape is rotated with a pinch roller sandwiching the magnetic tape. A capstan is provided to run the tape at a constant speed.

Such a capstan normally transfers the rotational force of a predetermined motor to a transmission belt wrapped around an output pulley fixed to the rotational shaft of the motor, or to a rotating tire or the like that is rotated by contacting the rotational shaft. It is configured to rotate by being transmitted via a transmission member.

Figures 7 and 8 show a conventional capstan rotation mechanism in which the rotational force of a motor is transmitted via a transmission belt.
This shows the number a.

In the figure, b is a flywheel having a predetermined size, and the flywheel b has a capstan C protruding from its axial center, and a pulley groove d on its outer peripheral surface.
is formed and rotatably supported by the bearing member e. f is a motor, with bearings g1 at both ends of its shaft center.
, g2 are provided. h is a rotating shaft of the motor f, and one end and a portion near the other end of the rotating shaft in the axial direction are rotatably supported by the bearings g1 and g2, and the other end is supported by the motor case. The output pulley i is fixed to the projected portion. j is an endless transmission belt, and the transmission belt j spans a pulley groove d formed in the flywheel b and an output pulley i with a predetermined tension.

When the motor f is driven, its rotation axis and the output pulley i are rotated together in a predetermined direction, so the transmission bell 2 is moved in a predetermined direction, which causes the flywheel to fly. Wheel b and capstan C are rotated in a predetermined direction.

(D. Problem to be solved by the invention) [Figures 7 and 8
By the way, the above-mentioned transmission belt j needs to be in contact with the output pulley i and flywheel b with an appropriate frictional force, so that the belt tension is applied to the output pulley i and flywheel b. On the other hand, it is wound under tension so that it is applied with a predetermined strength from the direction perpendicular to these axial directions, that is, from the sides.

Therefore, in such a capstan rotation mechanism a, a loss of rotational force (hereinafter referred to as "rotation loss") occurs around the rotation axis of the motor f due to the tension of the transmission belt j.

That is, tension forces P1 and P2 due to the transmission belt j are applied to the output pulley i and the flywheel b,
Of these tensions P1 and P2, the tension P1 applied to the output pulley i causes a force to be applied to the output pulley i to tilt it about the rotation axis. Due to such force, the portion of the rotating shaft supported by bearings g1 and g2 is biased and pressed against a portion of these bearings g1 and g2, so that the reaction caused by bearings g1 and g2 is Power,
In other words, relative lateral pressures Pa and Pb are applied. These side pressures Pa and Pb cause rotation loss around the rotation axis.

Incidentally, such rotation loss that occurs around the rotation axis can be avoided by bringing the outer peripheral surface of the rotary tire, on which the capstan etc. is erected, into contact with the rotation shaft of the motor from the side with a predetermined contact pressure. A similar problem occurs in a rotation transmission mechanism that rotates the stun.

(E. Means for Solving the Problems) In order to solve the above-mentioned problems, the rotation transmission mechanism of the present invention transmits the rotational force of a motor by winding it around an output pulley fixed to the rotating shaft of the motor. In a rotation transmission mechanism in which the belt or its outer circumferential surface is transmitted to a predetermined rotated member via a transmission member such as a rotating tire in which the belt or its outer peripheral surface contacts the rotating shaft from the radial direction with a predetermined contact pressure, the tension caused by the transmission belt A counter pulley or an idler tire is provided to apply tension or pressing force to the rotating shaft in the direction opposite to the direction of the pressing force by the rotating tires.

Therefore, according to the present invention, the lateral pressure on the rotating shaft due to the bearing due to the tension by the transmission belt or the pressing force by the rotating tires applied to the rotating shaft of the motor is
Since the tension or pressing force acting in the opposite direction to the tension or pressing force is substantially canceled out, rotation loss caused by side pressure on the rotating shaft can be significantly reduced.

(F. Embodiments) Details of the rotation transmission mechanism of the present invention will be described below according to embodiments shown in the accompanying drawings.

In each of the embodiments shown in the drawings, the rotation transmission mechanism of the present invention is applied to a capstan rotation mechanism in a tape recorder.

(F-1, First Embodiment) [Figures 1 and 2] Figures 1 and 2 show the first embodiment of the rotation transmission mechanism of the present invention.

(a, configuration) 1 is a capstan rotation mechanism.

Reference numeral 2 denotes a flywheel formed in a substantially disc shape with a predetermined diameter, and the flywheel 2 has a capstan 3 protruding from the axial center of its upper surface, and a pulley groove 4 on its outer peripheral surface. is formed and is rotatably supported by a bearing member 4 fixed to a chassis (not shown).

In the first factor, the outer circumference of the flywheel 2 is expressed by the diameter of the trough of the pulley groove 4.

Reference numeral 6 denotes a motor disposed a predetermined distance la# from the flywheel 2, and a rotary shaft 9 is supported in the motor by bearings 7.8 disposed vertically apart.

The upper end of the rotating shaft 9 is positioned so as to protrude upward from the motor case 10.

Illustrations of other elements in the motor 6 are omitted.

Reference numeral 11 denotes an integral pulley fixed to the upper end of the rotating shaft 9, and the integral pulley 11 is formed by integrally forming a first pulley 12 and a second pulley 13 having a smaller diameter than the first pulley 12. .

Reference numeral 14 denotes an endless transmission belt that is stretched between the first pulley 12 of the pulley assembly 11 and the pulley groove 4 formed in the flywheel 2 with a predetermined tension.

Note that the symbol P1 in the figure indicates the tension applied to the first pulley 12 by the transmission belt 14, and the direction of this tension P1 is the direction of the tension applied to the first pulley 1 of the transmission belt 14.
This is the direction of the composite tension that is created by the two tensions that occur at both ends of the part that is wrapped around 2.

Reference numeral 15 denotes a counter pulley, and the counter pulley 15 is arranged to sandwich the rotating shaft 9 so that its center of rotation is located on the opposite side to the direction of the tension P1 applied to the first pulley 12 by the transmission belt 14. , its diameter is considerably larger than the diameter of the second pulley 13 of the pulley assembly 11. The counter pulley 15 is located at approximately the same height as the second pulley 13, and is rotatably supported by a support shaft 16 that stands up from a chassis (not shown). Note that this support shaft 16 has a diameter considerably smaller than the diameter of the counter pulley 15.

17 is an endless counter belt, and the counter belt 17 is stretched between the second pulley 13 of the pulley unit 11 and the counter pulley 15 while maintaining a predetermined tension. .

Px is connected to the second pulley 1 by the counter belt 17
3, and the direction of this tension Px is opposite to the direction of the tension P1.

When the rotating shaft 9 is rotated, the pulley assembly 11 is rotated, so that the transmission belt 14 and the counter belt 17 are run, thereby rotating the flywheel 2 and the capstan 3, and the counter pulley 11 is also rotated. 15 will be rotated.

(b. Tension on the rotating shaft of the counter belt and its effect) The tension Px on the rotating shaft 9 of the motor 6 due to the counter belt 17 has the following strength.

That is, this tension Px has a strength that cancels out the relative lateral pressures Pa and Pb caused by the bearings 7.8 that are applied to the rotating shaft 9 when the tension P1 by the transmission belt 14 is applied to the rotating shaft 9. For example, it can be calculated using the following formula.

Note that the distance between the upper bearing 7 and the lower bearing 8 is a, and the distance between the upper bearing 7 and the first pulley 12 is b.
and the first pulley 12 and the second pulley 13
Let C be the distance between the two.

Therefore, first, the tension P1 of the transmission belt 14 and the side pressure Pa that the rotating shaft 9 receives from the bearing 7.8 due to this,
The following two relational expressions are obtained from the balance between Pb and the tension Px of the counter belt 17.

as Pa+(a+b+c)Px-(a+b)Pl
e a * ■Formula as Pb+(b+
c) Px-b 6 P 1 m
m a ■Formula...0 formula% formula%.

Therefore, the side pressures Pa and P that the rotating shaft 9 receives from the bearing 7.8 are
Find Px that minimizes the sum with b.

The fact that the absolute value of the sum of these two lateral pressures Pa and pb is the smallest can be expressed by the following differential equation.

Therefore, If we expand this equation as follows, we get Must The required Px can be obtained.

That is, Then, Furthermore, becomes.

Therefore.

becomes.

Therefore, if the tension Px due to the counter belt 17 is I1 determined by the above equation 0, then the transmission belt 14
The lateral pressure Pa due to the bearing 7.8 caused by the tension P1 of
Since Pb can be approximately O, the rotation loss of the rotating shaft 9 caused by the tension P1 of the transmission belt 14 is significantly reduced.

(C. Advantages of Providing a Counter Belt) By the way, if the counter belt 17 is provided, the rotating shaft 9
A part of the rotational force is used to rotate the counter pulley 15. That is, counter belt 1
7, the rotation loss caused by the tension P1 of the transmission belt 14 is significantly reduced, but in exchange, it is necessary to rotate the counter pulley 15, so the rotating shaft 9 is rotated accordingly. A loss will occur.

However, the rotation loss incurred in rotating the counter pulley 5 is much smaller than the rotation loss caused by the tension P1 of the transmission belt 14 in the case where the counter belt 17 is not provided.

This will be verified by the following calculation.

(c-1, general formula) Note that the rotation loss that occurs in the rotating shaft 9 to rotate the counter pulley 15 can be regarded as a rotation loss in the counter pulley 15, so this rotation loss and the rotation caused by the transmission belt 14 can be considered as rotation loss in the counter pulley 15. We will calculate this separately from loss.

Therefore, first, the rotation loss (L I M) of the rotating shaft 9 due to the tension P1 of the transmission belt 14 is determined by the following formula.

LIM Korea IPa*Pbl・r t'Pt...0 Formula Then, the rotation loss (L t c) occurring in the counter pulley 15 is determined by the following formula.

In addition, in the above ■ and the formula, rl is the radius of the rotating shaft 9, ru1 is the coefficient of friction between the rotating shaft 9 and the bearing 7.8, and rC is the radius of the support shaft 16 that supports the counter pulley 15. , PC is the coefficient of friction between the counter pulley 15 and its support shaft 16, RC is the radius of the counter pulley 15, and RM is the radius of the second pulley 13.

In addition, if the counter bell) 17 is not provided, the rotating shaft 9
The lateral pressures Pa and Pb that are applied to the cylindrical body can be obtained by rearranging the equations (1) and (2) by setting "PX" and rcJ in these equations to be O.

Therefore, it becomes, and the lateral pressure Pa and P according to this θ) formula and 0 formula
b can be regarded as the rotation loss L1 according to the above equation 0.

(c-2, specific calculation) Therefore, by substituting the following values into the above-mentioned equations 0 and 0, each rotation loss LIM, L'IC1 tension Px, lateral pressure Pa
, Pb.

a=5mm b=2.4n+m c=1.2m+a r1=Q, 075mm rc=0.06mm RM=1.5mm Rc=10mm gc depth 0.12 p,=43. o(g) The results of calculations using the above numerical values are as shown in the following table.

That is, if the counter belt 17 is not provided, the rotating shaft 9 will receive a lateral pressure of 63.6 g from the upper bearing 7 and a lateral pressure of 20.6 g from the lower bearing 8, resulting in rotation. Loss L and M are 0, 76 g @
It becomes C11.

However, when the counter belt 17 is provided, the rotating shaft 9
receives a lateral pressure of 2.1 g from the upper bearing 7 and a lateral pressure of -5.1 g from the lower bearing 8, and the resulting rotation loss LIM is suppressed to 0.06 g・C11l. The rotation loss LIC for rotating the counter pulley 5 is 0,04 g @cm
will occur. That is, when the counter belt 17 is provided, the rotation loss occurring in the rotating shaft 9 is 0.1 g/cm.

In this way, for example, when the counter belt 17 according to the above-mentioned specific values is provided, the rotation loss occurring in the rotating shaft 9 can be reduced to about one-eighth of the rotation loss when the counter belt 17 is not provided. become.

(F-2, Second Embodiment) [Figs. 3 and 4] Figs. 3 and 4 show a second embodiment IA of the rotation transmission mechanism of the present invention.

The difference between this second embodiment and the first embodiment is that there is a means for transmitting the rotational force of the motor to the capstan and a bearing that supports the rotary shaft of the motor. It is only a means to cancel out the lateral pressure received from the Therefore, in the explanation of the configuration, only the different parts will be explained, and the explanation of the same parts will be omitted by giving the same reference numerals as used in the first embodiment. Furthermore, the relationship between the use of symbols and the omission of explanations is the same in the third embodiment described later.

(a, Configuration) Reference numeral 18 denotes a flywheel that is formed into a substantially disk shape and has a capstan 3 erected from the center thereof. It is rotatably supported by the bearing member 5 while being in contact with a drive roller 19 fixed to the upper end of the bearing member 9 from the radial direction with a predetermined contact pressure.

20 is an idler tire. The idler tire 2
0 is formed into a substantially disk shape having a diameter substantially equal to the diameter of the flywheel 18, and its rotation center is located on the substantially opposite side to the rotation center of the flywheel 18 with the rotation shaft 9 of the motor 6 interposed therebetween. It is rotatably supported by a support shaft 21 having a fairly small diameter. A part of the outer peripheral surface of the idler tire 20 is connected to the rotating shaft 9.
Of the drive rollers 19 provided in the flywheel 1
The flywheel 18 is in contact with the portion opposite to the contact portion with a predetermined contact pressure, that is, with a contact pressure substantially equal to the contact pressure with which the flywheel 18 contacts the drive roller 19 .

Thus, when the rotating shaft 9 is rotated, the drive roller 19 is rotated, so that the flywheel 18 and the capstan 3 are rotated, and the idler tire 20 is also rotated.

(b. Effect of Idler Tire) According to such a capstan rotation mechanism IA, the rotation shaft 9 is hardly subjected to side pressure by the bearing 7.8.

That is, if the idler tire 20 were not provided, a force would be applied to the rotating shaft 9 to tilt it due to the pressing force P1 by the flywheel 18 applied to the upper end of the rotating shaft 9, and this force would cause the rotary shaft 9 to tilt. , the portion of the rotating shaft 9 supported by the bearings 7.8 is biased against some of these bearings 7, 8, so that the relative side pressures Pa, Pb from the bearings 7.8 are reduced.
will be added.

However, in this capstan rotation mechanism IA,
An idler tire 18 and an idler tire 20 are brought into contact with a drive roller 19 fixed to a rotating shaft 9 from opposite sides, that is, in a manner such that they sandwich the drive roller 19, and with substantially the same contact strength. Since it has been
The pressing force P1 by which the flywheel 18 presses the rotating shaft 9 from the radial direction is canceled by the pressing force P2 which presses the rotating shaft 9 from the eyeler tire 20. Therefore, the portion of the rotating shaft 9 that is supported by the bearings 7.8 is not biased and pressed against a portion of these bearings 7.8, so that lateral pressure by the bearings 7.8 is applied to the rotating shaft 9. There are almost no such things.

Therefore, if the idler tire 20 is not provided, rotation loss will occur in the rotating shaft 9 due to the lateral pressure caused by the bearing 7.8, but this rotation loss will be significantly reduced by providing the idler tire 20.

(C. Advantages of Providing an Idler Tire) By the way, by providing the idler tire 20, the rotating shaft 9 is hardly subjected to lateral pressure, but instead, a part of the rotational force of the rotating shaft 9 is transferred to the idler tire 20.
In order to make it rotate, it will be eaten.

However, the rotation loss incurred in rotating the idler tire 20 can be kept as small as possible, especially by appropriately selecting the ratio between the diameter of the drive roller 19 and the diameter of the idler tire 20.

This will be verified using the following calculation formula. Note that the distance between the bearings 7 and 8 is a, and the distance between the upper bearing 7 and the drive roller 1 is
Let b be the distance from the center of 9.

First, the bearing 7 when the idler tire 20 is not provided.
8, the relative side pressures Pa and Pb applied by 8 are obtained as follows: (a+b) ・P Pa=□ ...0 formula pb-□ ... [phase] formula, where P is the drive of the flywheel 18 This is the pressing force against the roller 19 (same as P1 above).

Therefore, the rotation loss LM of the rotating shaft 9 due to these side pressures Pa and Pb is: L M snow (p6 + pl)) * rM # gM
* * @Formula Note that rM is the radius of the rotating shaft 9, and pM is the coefficient of friction between the rotating shaft 9 and the bearing 7.8.

In addition, when the idler tire 20 is provided, the lateral pressure Pa
, Pb are considered to be O, so the rotation loss in this case is considered as the rotation loss in the idler tire 20. The rotation loss LA of this idler tire 20 is as follows.

Note that rA is a support shaft 21 that supports the idler tire 20.
, ^ is the friction coefficient between the idler tire 2o and the support shaft 21, RM is the radius of the drive roller 19, and RA is the radius of the idler tire 20.

Here, if we express the gate using P, (a+2b)
・PLM Tomi □ ・R Gate ・Use Gate
Therefore, in order to see the relationship between the rotation loss LM when the idler tire 20 is not provided and the rotation loss LA when the idler tire 20 is provided, for convenience, let rM=rA=r, Also, μM”J
If LA=use, (a 12 b) LM 腅 - 11P 11r・p... Life [stock] formula %
Formula % From this formula 0, the rotation loss LA for rotating the idler tire 20 can be kept as small as possible by making the radius RA of the idler tire 20 larger than the radius RM of the drive roller 19. I understand.

If the dimensions of each part are selected so that this L^ is smaller than LM, even if rotation loss Lp occurs due to the provision of the idler tire 20, the idler tire 2
This is advantageous in that the rotation loss can be suppressed to a smaller value than in the case where zero is not provided.

(F-3, Third Embodiment) [FIGS. 5 and 6] FIGS. 5 and 6 show a third embodiment IB of the rotation transmission mechanism of the present invention.

The only difference between this N43 embodiment and the first embodiment is the means for canceling the tension on the rotating shaft due to the transmission belt.

22 is an idler tire. Saitochi Tire 2
2 is formed into a substantially disk shape having a diameter considerably larger than the diameter of the rotating shaft 9, and its rotation center is on the flywheel 2 side of the rotating shaft 9, and the tension P1 applied to the rotating shaft 9 by the transmission belt 14 is It is located so that it is located in the direction of.

It is rotatably supported by a support shaft 23 having a fairly small diameter. Then, a part of the outer circumferential surface of the idler tire 22 is applied with a predetermined pressing force, that is, a force slightly weaker than the above-mentioned tension by the transmission belt 14, to a position of the rotating shaft 9 in the immediate vicinity of the part to which the pulley assembly 11 is fixed. They are in contact with pressure Py.

Therefore, although tension P1 is applied to the rotating shaft 9 by the transmission belt 14, this tension P1 is substantially canceled by the pressing force Py by the idler tire 22 acting on the rotating shaft 9 from the direction opposite to the direction of the tension P1. become.

Therefore, since the rotating shaft 9 is not tilted, the portion of the rotating shaft 9 supported by the bearings 7.8 is not biased and pressed against a part of these bearings 7.8, and therefore the bearing It hardly receives any relative lateral pressure from 7.8.

In this case as well, a part of the rotational force of the rotating shaft 9 is used to rotate the idler tire 22.
The rotation loss caused by this can be kept as small as possible, especially by making the diameter of the idler tire 22 as large as possible relative to the diameter of the rotating shaft 9.

(G. Effect of the invention) As is clear from the above description, the first rotation transmission mechanism of the present invention transmits the rotational force of the motor to an output pulley fixed to the rotation shaft of the motor. In a rotation transmission mechanism in which transmission is transmitted to a predetermined rotated member via a transmission belt, a counter output pulley is provided on the rotation shaft, and the rotation shaft is held in a position opposite to the direction of tension by the transmission belt. Accordingly, the first invention is characterized in that a counter pulley having a diameter larger than the diameter of the counter output pulley is arranged, and a counter belt is stretched between the counter pulley and the counter output pulley. According to , the tension by the counter belt acts in the opposite direction to the tension by the transmission belt, so the lateral pressure applied to the rotating shaft by the tension by the transmission belt is almost canceled out by the force applied to the rotating shaft by the tension of the counter belt. As a result, the loss of rotational force due to the side pressure applied to the rotating shaft can be further suppressed.

Moreover, since the counter output pulley is smaller in diameter than the counter pulley rotated by it, the rotational force exerted by the rotating shaft to rotate the counter pulley can be kept extremely small.

The second rotation transmission mechanism of the present invention is as follows.

A rotation transmission mechanism configured to transmit the rotational force of a motor to a predetermined rotated member via a transmission rotation member whose outer peripheral surface partially contacts the rotation shaft of the motor from a radial direction with a predetermined contact pressure. characterized in that an idler tire is provided whose rotation center is located opposite to the rotation center of the transmission rotating member across the rotation shaft, and the outer peripheral surface of the idler tire is brought into contact with the rotation shaft with a predetermined contact pressure. shall be.

Therefore, according to this second invention, the contact pressure on the rotating shaft by the idler tire is applied in the direction opposite to the direction of the contact pressure on the rotating shaft by the transmitting rotating member, so that the pressure on the rotating shaft by the rotation transmitting member is reduced. is substantially canceled out by the pressure exerted on the rotating shaft by the idler tire, thereby making it possible to further suppress the loss of rotational force due to the contact pressure applied to the rotating shaft.

In the second embodiment of the second invention, an idler tire whose outer circumferential diameter is considerably larger than the diameter of the portion of the rotating shaft with which the idler tire contacts is used. By doing so, the rotational force exerted on the rotating shaft to rotate the idler tire can be extremely reduced.

A third rotation transmission mechanism of the present invention transmits the rotational force of the motor to a predetermined rotated member via a transmission belt wrapped around an output pulley fixed to the rotation shaft of the motor. In the rotation transmission mechanism, an idler tire whose rotation center is on the rotating shaft side of the rotated member and located in the direction of tension by the transmission belt is provided, and the outer peripheral surface of the idler tire is applied to the rotating shaft with a predetermined contact pressure. It is characterized by being brought into contact.

Therefore, according to the third aspect of the invention, the contact pressure on the rotating shaft is applied by the idler tire in the direction opposite to the direction of the tension applied to the rotating shaft by the transmission belt. The pressure applied to the rotating shaft is substantially canceled out by the pressure applied to the rotating shaft by the idler tire, so that the loss of rotational force due to the tension applied to the rotating shaft can be further suppressed.

In the third embodiment of the third invention, an idler tire whose outer circumferential diameter is considerably larger than the diameter of the rotating shaft is used. The rotational force required to rotate the idler tire can be made extremely small.

In each of the embodiments described above, the rotation transmission mechanism of the present invention is applied to a capstan rotation mechanism, but the present invention is not limited to such application examples, and the rotational force of the motor is applied to a transmission belt. The present invention can be applied to various rotation transmission mechanisms that transmit the rotation to a predetermined member to be rotated via a transmission member that is brought into contact with the rotation shaft of the motor while applying side pressure, such as a rotary tire or a rotary tire.

[Brief explanation of drawings]

1 and 2 show a first embodiment in which the rotation transmission mechanism of the present invention is applied to a capstan rotation mechanism in a tape recorder. FIG. 1 is a plan view, and FIG. 2 is a partially cutaway 3 and 4 show a second embodiment in which the rotation transmission mechanism of the present invention is applied to a capstan rotation mechanism in a tape recorder; FIG. 3 is a plan view, and FIG. is a front view, FIGS. 5 and 6 show a third embodiment in which the rotation transmission mechanism of the present invention is applied to a capstan rotation mechanism in a tape recorder, FIG. 5 is a plan view, and FIG. A front view, FIG. 7, and FIG. 8 show an example of a conventional capstan rotation mechanism in a tape recorder, with FIG. 7 being a plan view and FIG. 8 being a front view. Explanation of symbols 1: Rotation transmission mechanism. 3φ... Rotated member, 611... Motor, 9. Fist.
Rotating shaft, 12-Φ output pulley, 13...output pulley for counter, 14-O-transmission belt, 1511a fist counter pulley, F-1 counter belt, IA...rotation transmission mechanism, 18-fist-transmission Rotating member, 20... Idler tire, 1B... Rotation transmission mechanism, 22... Idler tire - "Ouko0)?+-1-Go111/1A 7-' Plan view (L east (I column) Figure 7 Plus 50 (I L Song example p Figure 8

Claims (3)

[Claims] (1) In a rotation transmission mechanism that transmits the rotational force of a motor to a predetermined rotated member via a transmission belt wrapped around an output pulley fixed to the rotation shaft of the motor, a counter output is provided on the rotation shaft. A pulley is provided, and a counter pulley having a diameter larger than the diameter of the counter output pulley is disposed at a position opposite to the direction of tension by the transmission belt across the rotating shaft, and the counter pulley and the counter output pulley are arranged. A rotation transmission mechanism characterized by a counter belt spanning between (2) The rotational force of the motor is transmitted to a predetermined rotated member via a transmission rotating member whose outer peripheral surface is partially in contact with the rotating shaft of the motor with a predetermined contact pressure from the radial direction. In the rotation transmission mechanism, an idler tire is provided whose rotation center is located on the opposite side of the rotation center of the transmission rotating member with the rotation shaft in between, and the outer peripheral surface of the idler tire is brought into contact with the rotation shaft with a predetermined contact pressure. A rotation transmission mechanism characterized by (3) In a rotation transmission mechanism that transmits the rotational force of a motor to a predetermined rotated member via a transmission belt wrapped around an output pulley fixed to a rotation shaft of the motor, the rotation center is the transmission belt. A rotation transmission mechanism comprising: an idler tire positioned in the direction of tension, and an outer circumferential surface of the idler tire being brought into contact with a rotating shaft with a predetermined contact pressure.