JP2012097819A - Driving force switching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent increase of impact noise generated by a one-way clutch when a reversible drive motor starts or a driving force is switched for the rotational direction of the drive motor.SOLUTION: This driving force switching device 30A includes: the reversible drive motor 51; first and second rotating shafts 31A and 41A rotatably connected to the drive motor 51 through a transmission mechanism; a first one-way clutch 52 which transmits the rotational force of the drive motor 51 to rotationally drive the first rotating shaft 31A only when the drive motor 51 rotates forwardly; and a second one-way clutch 58 which transmits the rotational force of the drive motor 51 to rotationally drive the second rotating shaft 41A only when the drive motor 51 rotates reversely. In the driving force switching device 30A, the first and second one-way clutches 52 and 58 are fitted into the motor shaft 51a of the drive motor 51 which is axially shorter than the first and second rotating shafts 31A and 41A.

Description

  The present invention relates to a driving force for driving at least one or more rotary shafts connected to a drive motor capable of forward / reverse rotation via a transmission mechanism by switching the driving force using a one-way clutch in the rotation direction of the drive motor. The present invention relates to a switching device.

  Generally, a one-way clutch (one-way clutch), which is one of the drive mechanism component parts, has a function of transmitting driving force (rotational force) only in one direction and free in the other direction. It is widely used in various driving force switching devices.

  As an example to which this type of driving force switching device is applied, there is a photographic paper feeding device in a photographic processor (see, for example, Patent Document 1).

  In the photographic paper feeding device in the photographic processing machine disclosed in Patent Document 1, although illustration is omitted here, one photographic paper and the other photographic paper are selected by the driving force of a drive motor capable of forward and reverse rotation. It is configured to be able to pay out automatically.

  Specifically, the rotational force from the drive motor is rotated by a rotation shaft of a first feeding roller for feeding one photographic paper through a plurality of rings and a timing belt, and a second for feeding the other photographic paper. It is selectively transmitted to the rotation shaft of the feeding roller.

  At this time, the first feeding roller is driven by the drive motor with the first one-way clutch fitted to the rotating shaft, and the first one-way clutch is transmitted with the driving force during the forward rotation of the drive motor. Thus, the rotational directions of the power transmission side and the non-transmission side are set.

  On the other hand, the second feed roller is driven by a drive motor with the second one-way clutch fitted on the rotating shaft, and the second one-way clutch is transmitted with a driving force when the drive motor rotates in the reverse direction. Thus, the rotational directions of the power transmission side and the non-transmission side are set.

  Accordingly, since the driving force is transmitted in a state where the first feeding roller and the second feeding roller are in opposite directions with respect to the rotation direction of the driving motor, one photographic paper and the other photographic paper are It is described that the apparatus can be selectively delivered by the driving force of a single driving motor that rotates forward and backward, thereby reducing the number of parts and reducing the size and weight of the apparatus.

JP 2000-206624 A

  By the way, in the photographic paper feeding device in the photographic processing machine disclosed in Patent Document 1 described above, the first and second one-way clutches fitted to the respective rotation shafts of the first and second feeding rollers are provided by the drive motor. An impact sound is generated at the time of start-up or when the driving force is switched with respect to the rotational direction of the drive motor, and this impact sound is propagated to the respective rotation shafts of the first and second feeding rollers. Since both the shafts are long, each impact sound from each one-way clutch propagated to each rotating shaft is increased. Therefore, the first and second feeding rollers are selectively driven to rotate in a quiet room. In such a case, each of the increased impact sounds is a problem for the user.

  Therefore, the present invention rotates at least one or more rotating shafts connected to a drive motor capable of forward / reverse rotation via a transmission mechanism by switching the driving force using a one-way clutch in the rotation direction of the drive motor. At this time, an object of the present invention is to provide a driving force switching device configured so that the impact sound generated from the one-way clutch does not increase when the driving motor is started or when the driving force is switched in the rotation direction of the driving motor.

The present invention has been made in view of the above problems, and the invention according to claim 1 includes a drive motor capable of forward and reverse rotation,
At least one rotating shaft rotatably connected to the drive motor via a transmission mechanism;
A one-way clutch that transmits the rotational force of the drive motor only during rotation of either one of the forward rotation and the reverse rotation of the drive motor to drive the rotation shaft;
In the driving force switching device provided with
The one-way clutch is fitted to a motor shaft of the drive motor having a shorter shaft length than the rotating shaft or an intermediate shaft provided in the transmission mechanism and having a shorter shaft length than the rotating shaft. The driving force switching device characterized by the above.

The invention according to claim 2 is a drive motor capable of forward and reverse rotation,
First and second rotating shafts rotatably connected to the drive motor via a transmission mechanism;
A first one-way clutch that transmits the rotational force of the drive motor only during the forward rotation of the drive motor to drive the first rotary shaft to rotate;
A second one-way clutch that transmits the rotational force of the drive motor only during the reverse rotation of the drive motor and drives the second rotary shaft to rotate;
In the driving force switching device provided with
The first and second one-way clutches are provided in the motor shaft of the drive motor having a shorter shaft length than the first and second rotating shafts or in the transmission mechanism and the first and second The driving force switching device is characterized in that it is fitted to an intermediate shaft having a shaft length shorter than that of the rotary shaft.

  According to the driving force switching device according to claim 1, at least one or more rotary shafts rotatably connected via a drive motor capable of forward / reverse rotation and a transmission mechanism are used during forward rotation and reverse rotation of the drive motor. When rotating using a one-way clutch that transmits the rotational force of the drive motor only during either rotation, the one-way clutch is provided in the motor shaft of the drive motor whose shaft length is shorter than the rotation shaft or in the transmission mechanism Since the impact sound generated from the one-way clutch does not increase on the motor shaft or the intermediate shaft by being fitted to the intermediate shaft that is shorter than the rotating shaft, the drive force switching device is installed in a quiet room. Even if it is operated, the user does not hear it, and the quality of the driving force switching device can be improved.

  According to the driving force switching device of the second aspect, the first rotation shaft that is rotatably coupled to the forward / reverse driving motor and the transmission mechanism is used to rotate the driving motor only during the forward rotation of the driving motor. The second rotary shaft that is rotationally driven using the first one-way clutch that transmits force and that is rotatably connected to the forward and reverse drive motor via the transmission mechanism is used only when the drive motor is reversely rotated. When the second one-way clutch that transmits the rotational force of the drive motor is driven to rotate, the first and second one-way clutches have a shorter motor length than the first and second rotary shafts. Each impact sound generated from the first and second one-way clutches by being fitted to a shaft or an intermediate shaft provided in the transmission mechanism and having a shorter shaft length than the first and second rotating shafts. On the motor shaft Since not increased on the intermediate shaft, it is operated in a quiet room the driving force switching device does not become harsh to the user, thereby improving the quality of the driving force switching device.

It is the side view typically shown in order to demonstrate the paper feeder which applied the driving force switching apparatus which concerns on this invention. It is the block diagram which showed typically the driving force switching apparatus of Example 1 which concerns on this invention. It is the block diagram which showed typically the driving force switching apparatus of Example 2 which concerns on this invention.

  Hereinafter, an embodiment of a driving force switching device according to the present invention will be described in detail in the order of Embodiment 1 and Embodiment 2 with reference to FIGS.

  Before describing the driving force switching device according to the present invention, a paper feeding device to which the driving force switching device is applied will be described with reference to FIG.

  A sheet feeding device 10 shown in FIG. 1 has an image forming unit (printing unit) that forms (prints) an image on a sheet by an inkjet printing method, a stencil printing method, a laser beam printing method, a thermal transfer printing method, or the like. And an image forming apparatus (not shown) having an image forming unit (copying unit) for copying an image.

  In the sheet feeding device 10 described above, for example, a first sheet feeding tray 11 for A4 size (297 mm × 210 mm) and a second sheet feeding tray 21 for A3 size (420 mm × 297 mm) are installed separately in the upper and lower sides. Yes.

  On the bottom plate 11a in the first paper feed tray 11, the first paper mounting plate 12 is provided so as to be movable up and down by the urging force of the first compression spring 14 via the pin 13 as a fulcrum. A plurality of A4 size papers P1 are stacked on the first paper mounting plate 12.

  The first paper feed roller 15 is brought into contact with the uppermost paper P1 among the plurality of papers P1 stacked on the first paper mounting plate 12, and the front plate 11b of the first paper feed tray 11 is used. The first rolling roller 16 and the first friction plate 17 are disposed opposite to each other on the outer side of the driving force switching device according to the present invention downstream of the first rolling roller 16 and the first friction plate 17. A first driving roller 31 and a first driven roller 32 for paper conveyance provided in 30 are installed opposite to each other, and communicate with an image forming unit (printing unit or copying unit) downstream of these rollers 31 and 32. A paper transport path HR is installed.

  The first paper feed roller 15 and the first paper roller 16 are connected to a first drive motor 18 that can rotate in one direction via a transmission mechanism (not shown), and a first drive roller 31 for paper conveyance. Is connected to a drive motor 51 provided in the drive force switching device 30 and capable of forward and reverse rotation via a transmission mechanism (not shown).

  On the other hand, the second paper mounting plate 22 is also provided on the bottom plate 21a in the second paper feed tray 21 so as to be movable up and down by the urging force of the second compression spring 24 via the pin 23 serving as a fulcrum. A plurality of A3 size sheets P2 are stacked on the second sheet mounting plate 22.

  The second paper feed roller 25 is brought into contact with the uppermost paper P2 among the plurality of papers P2 stacked on the second paper mounting plate 22 and the front side plate 21b of the second paper feed tray 21 is used. The second rolling roller 26 and the second friction plate 27 are disposed opposite to each other on the outer side of the driving force switching device 30 in the downstream of the second winding roller 26 and the second friction plate 27. A second driving roller 41 and a second driven roller 42 for conveying the sheet are installed opposite to each other, and the downstream of these rollers 41 and 42 merges with the sheet conveying path HR described above and passes through the sheet conveying path HR. It is designed to be shared.

  The second paper feed roller 25 and the second roller 26 are connected to a second drive motor 28 that can rotate in one direction via a transmission mechanism (not shown), and the second drive roller 41 for paper conveyance. Is connected to a drive motor 51 provided in the drive force switching device 30 and capable of forward and reverse rotation via a transmission mechanism (not shown).

  In the paper feeding device 10 configured as described above, when feeding A4 size paper P1, the first driving motor 18 is driven to simultaneously turn the first paper feeding roller 15 and the first paper roller 16 counterclockwise. The uppermost sheet P1 is fed in the direction of the arrow by the first sheet feeding roller 15, and then the sheet P1 is nipped and conveyed between the first sheeting roller 16 and the first friction plate 17. By separating the sheets one by one and preventing double feeding, the first driving roller 31 is rotated in the clockwise direction by rotating the driving motor 51 provided in the driving force switching device 30 in the forward and reverse directions. The fed paper P1 is conveyed to the image forming unit while being sandwiched between the first drive roller 31 and the first driven roller 32.

  On the other hand, when the A3 size paper P2 is fed, the uppermost layer paper P2 is fed by the second paper feed roller 25 driven by the second drive motor 28 as in the case of the A4 size. By passing between the second roller 26 and the second friction plate 27, and then rotating the drive motor 51 provided in the driving force switching device 30 in the forward / reverse direction reversely differently from the above. The second driving roller 41 is rotated in the clockwise direction, and the fed paper P2 is conveyed to the image forming unit while being sandwiched between the second driving roller 41 and the second driven roller 42. Yes.

  At this time, in the driving force switching device 30, the first driving roller 31 that is driven at the time of forward rotation of the drive motor 51 that can be rotated forward and backward, and the second driving roller 41 that is driven at the time of reverse rotation of the driving motor 51 are: Since the rotation direction of the drive motor 51 is different, the drive motor 51 is not driven at the same time, and one of the first and second drive rollers 31 and 41 is rotated by the drive motor 51. Sometimes, the other roller 41, (31) is not transmitted with the rotational force of the drive motor 51, and the drive force using two one-way clutches (one-way clutch) with respect to the rotational direction of the drive motor 51. This is described in detail in Examples 1 and 2 below.

  The driving force switching device according to the first embodiment of the present invention is configured to be applicable to, for example, the paper feeding device 10 described above with reference to FIG.

  In the driving force switching device according to the first embodiment, one of the total two rotating shafts that are rotationally driven via the drive motor capable of forward and reverse rotation and the transmission mechanism is connected to the other rotating shaft during the forward rotation of the driving motor. When the rotary shaft is selectively switched during the reverse rotation of the drive motor and driven to rotate, the motor shaft of the drive motor having a shorter shaft length than the two rotary shafts is used for the forward rotation drive and the reverse rotation drive. By fitting two one-way clutches, improvements are made so that the impact noise generated in each one-way clutch does not increase when the drive motor is started or when the drive force is switched in the rotational direction of the drive motor.

  That is, as shown in FIG. 2, in the driving force switching device 30A (30) according to the first embodiment of the present invention, a motor shaft 51a having a short shaft length L1 projects in front of a drive motor 51 capable of forward and reverse rotation. A first timing pulley 53 with a first one-way clutch 52 fitted to the motor shaft 51a and a first gear 59 with a second one-way clutch 58 fitted are attached.

  At this time, the first one-way clutch 52 fitted between the motor shaft 51a of the drive motor 51 and the first timing pulley 53 rotates the drive motor 51 forward, for example, clockwise, for example. When the first timing pulley 53 can rotate forward clockwise integrally with the motor shaft 51a and the drive motor 51 rotates counterclockwise, the rotational force of the drive motor 51 is transmitted. The direction in which the first one-way clutch 52 is attached is preset so that the first timing pulley 53 is free with respect to the motor shaft 51a without being transmitted.

  On the other hand, the second one-way clutch 58 fitted between the motor shaft 51a of the drive motor 51 and the first gear 59 is rotated when the drive motor 51 is rotated in the counterclockwise direction, for example. When the rotational force is transmitted, the first gear 59 can rotate counterclockwise integrally with the motor shaft 51a, and the rotational force of the drive motor 51 is transmitted when the drive motor 51 is rotated forward clockwise. The mounting direction of the second one-way clutch 58 is set in advance so that the first gear 59 is free with respect to the motor shaft 51a.

  Further, between the first timing pulley 53 attached to the motor shaft 51a of the drive motor 51 via the first one-way clutch 52 and the second timing pulley 55 fixed to one end of the rotation shaft 31A of the first drive roller 31. A timing belt 54 is stretched over.

  At this time, the first drive roller 31 is integrally fixed to the rotary shaft 31A having a longer shaft length L2 than the motor shaft 51a of the drive motor 51 by baking or the like. The first driven roller 32 driven by the first drive roller 31 also has a rubber roller 32B integrally fixed to the rotary shaft 32A in the same manner as described above.

  The right end side of the rotation shaft 31A of the first drive roller 31 is rotatably supported by a bearing 57 attached to the bearing support member 56. The bearing support member and the bearing that support the left end side of the rotation shaft 31A are illustrated. The illustration of the bearing support members and the bearings that support both ends of the rotation shaft 32A of the first driven roller 32 is also omitted.

  From the above, the first transmission mechanism on the first drive roller 31 side includes the first timing pulley 53, the timing belt 54, and the second timing pulley 55.

  On the other hand, the first gear 59 attached to the motor shaft 51a of the drive motor 51 via the second one-way clutch 58 meshes with the second gear 60 fixed to one end of the rotation shaft 41A of the second drive roller 41. .

  At this time, the second drive roller 41 is also integrally fixed to the rotary shaft 41A having a longer shaft length L3 than the motor shaft 51a of the drive motor 51 by baking or the like, as in the first drive roller 31. ing. The second driven roller 42 driven by the second drive roller 41 also has a rubber roller 42B integrally fixed to the rotary shaft 42A in the same manner as described above.

  Further, the right end side of the rotation shaft 41A of the second drive roller 41 is rotatably supported by a bearing 62 attached to the bearing support member 61, but the bearing support member and the bearing that support the left end side of the rotation shaft 41A are illustrated. The illustration of the bearing support members and the bearings that support both ends of the rotating shaft 42A of the second driven roller 42 is also omitted.

  From the above, the second transmission mechanism on the second drive roller 41 side is composed of the first gear 59 and the second gear 60.

  Here, the operation of the driving force switching device 30A according to the first embodiment configured as described above will be described.

  First, when the drive motor 51 is rotated clockwise in the clockwise direction, the first one-way clutch 52 fitted between the motor shaft 51a of the drive motor 51 and the first timing pulley 53 is driven as described above. Since the second one-way clutch 58 set in the transmission direction and fitted between the motor shaft 51a and the first gear 59 is set in the non-driving force transmission direction, the first one-way clutch 52 is fitted. The attached first timing pulley 53 rotates in the clockwise direction integrally with the motor shaft 51a, and this rotation is applied to the second timing pulley 55 fixed to the rotating shaft 31A of the first drive roller 31 via the timing belt 54. As a result, the first driving roller 31 rotates in the clockwise direction and the first driven roller 32 rotates in the counterclockwise direction.

  On the other hand, when the drive motor 51 rotates forward, the second one-way clutch 58 is free with respect to the motor shaft 51a of the drive motor 51, so the first gear 59 fitted with the second one-way clutch 58 does not rotate. Therefore, the second drive roller 41 to which the second gear 60 meshed with the first gear 59 is fixed does not rotate.

  Next, when the drive motor 51 is rotated counterclockwise, the second one-way clutch 58 fitted between the motor shaft 51a of the drive motor 51 and the first gear 59 is driven as described above. Since the first one-way clutch 52 set in the force transmission direction and fitted between the motor shaft 51a and the first timing pulley 53 is set in the non-driving force transmission direction, the second one-way clutch 58 is set. The first gear 59 fitted with the motor rotates counterclockwise integrally with the motor shaft 51a, and the rotation shaft 41A of the second drive roller 41 to which the second gear 60 meshed with the first gear 59 is fixed is provided. The second driven roller 32 rotates in the clockwise direction and the second driven roller 32 rotates in the counterclockwise direction.

  On the other hand, when the drive motor 51 rotates in the reverse direction, the first one-way clutch 52 is free with respect to the motor shaft 51a of the drive motor 51, so the first timing pulley 53 with the first one-way clutch 52 attached rotates. Therefore, the first driving roller 31 connected via the first timing pulley 53 and the timing belt 54 also does not rotate.

  Accordingly, the first one-way clutch 52 for rotating the rotation shaft 31A of the first drive roller 31 when the drive motor 51 is rotated forward, and the second drive roller 41 when the drive motor 51 is rotated reversely. Since the second one-way clutch 58 for rotating the rotation shaft 41A is fitted to the motor shaft 51a having a shorter shaft length than the rotation shafts 31A and 41A of the first and second drive rollers 41, the drive motor Since each impact sound generated from the first and second one-way clutches 52, 58 does not increase on the motor shaft 51a at the time of starting 51 or switching the driving force in the rotation direction of the driving motor 51, the driving force switching of the first embodiment is performed. Even if the device 30A is operated in a quiet room, the user does not hear it and the quality of the driving force switching device 30A of the first embodiment is improved. It can be.

  The driving force switching device according to the second embodiment of the present invention is also configured to be applicable to, for example, the paper feeding device 10 described above with reference to FIG.

  In the driving force switching device according to the second embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals, and the components described above are appropriately described as necessary. The components different from those in the first embodiment will be described with new reference numerals.

  In the driving force switching device of the second embodiment, one of the total two rotating shafts that are rotationally driven via a drive motor capable of forward and reverse rotation and a transmission mechanism is connected to the other rotating shaft during the forward rotation of the driving motor. When the rotary shaft is selectively switched during the reverse rotation of the drive motor and driven to rotate, the intermediate shaft in the transmission mechanism having a shorter shaft length than the two rotary shafts is used for forward rotation drive and reverse rotation drive. By fitting the two one-way clutches, improvement is made so that the impact sound generated in each one-way clutch does not increase when the drive motor is started or when the driving force is switched in the rotational direction of the drive motor.

  That is, as shown in FIG. 3, in the driving force switching device 30B (30) according to the second embodiment of the present invention, the motor shaft 51a protrudes in front of the drive motor 51 capable of forward and reverse rotation. The first gear 71 is fixed.

  Further, in the transmission mechanism provided between the drive motor 51 and the first drive roller 31, the intermediate shaft 72 includes a bearing 74 in which both ends are attached to the lower portion of the left bearing support member 73, and a right bearing. A bearing 77 attached to the support member 76 is rotatably supported.

  At this time, the shaft length L4 of the intermediate shaft 72 provided in the transmission mechanism is greater than the shaft length L2 of the rotation shaft 31A of the first drive roller 31 and the shaft length L3 of the rotation shaft 41A of the second drive roller 41. Is also set short.

  The second gear 78 fixed to the right end side of the intermediate shaft 72 meshes with the first gear 71 fixed to the motor shaft 51 a of the drive motor 51, and the first gear 71 and the second gear 78 are engaged. Since the first transmission mechanism is configured, the intermediate shaft 72 rotates in the opposite direction with respect to the rotation direction of the drive motor 51.

  Further, a third gear 80 having a first one-way clutch 79 fitted to the left end side of the intermediate shaft 72 is attached, and a first timing at which a second one-way clutch 82 is fitted to the central portion of the intermediate shaft 72 is attached. A pulley 83 is attached.

  At this time, the first one-way clutch 79 fitted between the intermediate shaft 72 and the third gear 80 in the transmission mechanism rotates the drive motor 51 forward, for example, clockwise. When the rotational force is transmitted and the third gear 80 can rotate counterclockwise integrally with the intermediate shaft 72, and when the drive motor 51 is rotated counterclockwise, the rotational force of the drive motor 51 is transmitted. Instead, the mounting direction of the first one-way clutch 79 is set in advance so that the third gear 80 is free with respect to the intermediate shaft 72.

  On the other hand, the second one-way clutch 82 fitted between the intermediate shaft 72 in the transmission mechanism and the first timing pulley 83 rotates the drive motor 51, for example, when it rotates counterclockwise. When the first timing pulley 83 can rotate in the clockwise direction integrally with the intermediate shaft 72 and the drive motor 51 is rotated in the clockwise direction, the rotational force of the drive motor 51 is transmitted. Instead, the mounting direction of the second one-way clutch 82 is set in advance so that the first timing pulley 83 is free with respect to the intermediate shaft 72.

  The third gear 80 attached to the intermediate shaft 72 via the first one-way clutch 79 meshes with a fourth gear 81 fixed to one end of the rotating shaft 31A of the first drive roller 31.

  At this time, the first drive roller 31 is integrally fixed to the rotary shaft 31A having a longer shaft length L2 than the intermediate shaft 72 by baking or the like. The first driven roller 32 driven by the first drive roller 31 also has a rubber roller 32B integrally fixed to the rotary shaft 32A in the same manner as described above.

  Further, the right end side of the rotation shaft 31A of the first drive roller 31 is rotatably supported by the bearing 75 attached to the upper portion of the bearing support member 73. The bearing support member and the bearing that support the left end side of the rotation shaft 31A. The illustrations of the bearing support members and the bearings that support both ends of the rotating shaft 32A of the first driven roller 32 are also omitted.

  From the above, the second transmission mechanism on the first drive roller 31 side includes the third gear 80 and the fourth gear 81.

  On the other hand, the timing belt 84 is interposed between the first timing pulley 83 attached to the intermediate shaft 72 via the second one-way clutch 82 and the second timing pulley 85 fixed to one end of the rotating shaft 41A of the second drive roller 41. Is over.

  At this time, the second driving roller 41 is also integrally fixed to the rotating shaft 41A having a longer shaft length L3 than the intermediate shaft 72 by baking or the like, as in the first driving roller 31. The second driven roller 42 driven by the second drive roller 41 also has a rubber roller 42B integrally fixed to the rotary shaft 42A in the same manner as described above.

  Further, the right end side of the rotation shaft 41A of the second drive roller 41 is rotatably supported by a bearing 87 attached to the bearing support member 86, but the bearing support member and the bearing that support the left end side of the rotation shaft 41A are illustrated. The illustration of the bearing support members and the bearings that support both ends of the rotating shaft 42A of the second driven roller 42 is also omitted.

  From the above, the third transmission mechanism on the second drive roller 41 side includes the first timing pulley 83, the timing belt 84, and the second timing pulley 85.

  Here, the operation of the driving force switching device 30B according to the second embodiment configured as described above will be described.

  First, when the drive motor 51 is rotated clockwise in the clockwise direction, the intermediate shaft 72 to which the second gear 78 meshed with the first gear 71 fixed to the motor shaft 51a of the drive motor 51 is fixed counterclockwise. Rotate.

  Here, as described above, the first one-way clutch 79 fitted between the intermediate shaft 72 and the third gear 80 during the forward rotation of the drive motor 51 is set in the driving force transmission direction, and the intermediate shaft Since the second one-way clutch 82 fitted between the first timing pulley 83 and the first timing pulley 83 is set in the non-driving force transmitting direction, the third gear 80 fitted with the first one-way clutch 79 is intermediate. The rotating shaft 31A of the first driving roller 31 that rotates counterclockwise integrally with the shaft 72 and fixes the fourth gear 81 meshed with the third gear 80 rotates clockwise, and the second driven roller 32 rotates. Rotates counterclockwise.

  On the other hand, since the second one-way clutch 82 is free with respect to the intermediate shaft 72 during the forward rotation of the drive motor 51, the first timing pulley 83 fitted with the second one-way clutch 82 does not rotate. The second drive roller 41 connected via the first timing pulley 83, the timing belt 84, and the second timing pulley 85 also does not rotate.

  Next, when the drive motor 51 is rotated counterclockwise, the intermediate shaft 72 to which the second gear 78 meshed with the first gear 71 fixed to the motor shaft 51a of the drive motor 51 is fixed is clockwise. Rotate to.

  Here, as described above, when the drive motor 51 rotates in the reverse direction, the second one-way clutch 82 fitted between the intermediate shaft 72 and the first timing pulley 83 is set in the driving force transmission direction, and the intermediate Since the first one-way clutch 79 fitted between the shaft 72 and the third gear 80 is set in the non-driving force transmitting direction, the first timing pulley 83 fitted with the second one-way clutch 82 is The rotation rotates in the clockwise direction integrally with the intermediate shaft 72, and this rotation is transmitted to the second timing pulley 85 fixed to the rotation shaft 41 </ b> A of the second drive roller 41 via the timing belt 84. The second driven roller 42 rotates clockwise and the second driven roller 42 rotates counterclockwise.

  On the other hand, since the first one-way clutch 79 is free with respect to the intermediate shaft 72 during the reverse rotation of the drive motor 51, the third gear 80 fitted with the first one-way clutch 79 does not rotate. The first drive roller 31 to which the fourth gear 81 meshed with the third gear 80 is also not rotated.

  Therefore, the first one-way clutch 79 for rotating the rotation shaft 31A of the first drive roller 31 when the drive motor 51 is rotated forward, and the second drive roller 41 when the drive motor 51 is rotated reversely. The second one-way clutch 82 for rotationally driving the rotary shaft 41A is fitted to the intermediate shaft 72 in the transmission mechanism having a shorter shaft length than the rotary shafts 31A and 41A of the first and second drive rollers 31 and 41. Therefore, the impact noise generated from the first and second one-way clutches 79 and 82 does not increase on the intermediate shaft 72 when the drive motor 51 is started or when the driving force is switched in the rotational direction of the drive motor 51. Even if the driving force switching device 30B of Example 2 is operated in a quiet room, the user does not hear it and the quality of the driving force switching device 30B of Example 2 is improved. It can be.

  As described above in detail, the technical ideas of the first and second embodiments are not used in order to prevent the impact sound generated from the one-way clutch from being increased when the drive motor capable of forward / reverse rotation is started or when the driving force is switched in the rotational direction of the drive motor 51. If applied, at least one or more rotary shafts are rotatably connected via a drive motor capable of forward / reverse rotation and a transmission mechanism, and in one direction when the drive motor rotates either forwardly or reversely In a driving force switching device that drives at least one or more rotating shafts using a one-way clutch that transmits driving force only in the other direction or only in the other direction, the motor shaft of the driving motor whose shaft length is shorter than the rotating shaft. Alternatively, it may be fitted to an intermediate shaft provided in the transmission mechanism and having a shorter shaft length than the rotation shaft.

10: Paper feeding device,
11: First paper feed tray, 15: First paper feed roller,
21 ... second paper feed tray, 25 ... second paper feed roller,
30 ... Driving force switching device,
30A ... Driving force switching device of Example 1,
30B ... Driving force switching device of Example 2,
31 ... 1st driving roller, 31A ... Rotating shaft, 32 ... 1st driven roller,
41 ... second driving roller, 41A ... rotating shaft, 42 ... second driven roller,
51: Drive motor capable of forward / reverse rotation, 51a: Motor shaft,
52 ... the first one-way clutch in the first embodiment,
53. First timing pulley in the first embodiment,
58 ... the second one-way clutch in the first embodiment,
59 ... 1st gear in Example 1,
71 ... 1st gear in Example 2, 72 ... Intermediate shaft,
78 ... the second gear in the second embodiment,
79 ... the first one-way clutch in the second embodiment,
80 ... the third gear in the second embodiment,
82 ... the second one-way clutch in the second embodiment,
83 ... the first timing pulley in the second embodiment,
P1, P2 ... paper.

Claims (2)

A drive motor capable of forward and reverse rotation;
At least one rotating shaft rotatably connected to the drive motor via a transmission mechanism;
A one-way clutch that transmits the rotational force of the drive motor only during rotation of either one of the forward rotation and the reverse rotation of the drive motor to drive the rotation shaft;
In the driving force switching device provided with
The one-way clutch is fitted to a motor shaft of the drive motor having a shorter shaft length than the rotating shaft or an intermediate shaft provided in the transmission mechanism and having a shorter shaft length than the rotating shaft. A driving force switching device characterized by A drive motor capable of forward and reverse rotation;
First and second rotating shafts rotatably connected to the drive motor via a transmission mechanism;
A first one-way clutch that transmits the rotational force of the drive motor only during the forward rotation of the drive motor to drive the first rotary shaft to rotate;
A second one-way clutch that transmits the rotational force of the drive motor only during the reverse rotation of the drive motor and drives the second rotary shaft to rotate;
In the driving force switching device provided with
The first and second one-way clutches are provided in the motor shaft of the drive motor having a shorter shaft length than the first and second rotating shafts or in the transmission mechanism and the first and second A driving force switching device characterized by being fitted to an intermediate shaft having a shaft length shorter than that of the rotating shaft.

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