JP2009299812A - Gear device and disk device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gear device of simple and compact structure reduced in the number of parts items and capable of restricting backlash to zero in normal and reverse operation without changing an original mechanism large. <P>SOLUTION: This gear device for transmitting driving force of a driving gear fitted to a driving shaft to a driven gear is structured by fitting an auxiliary gear, of which plate thickness is smaller than that of the driving gear and in which the number of tooth is smaller by one than that of the driving gear, to the driving shaft by friction fitting to the driving gear, and engaging both the driving gear and the auxiliary gear with the driven gear. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a gear device and a disk device using the gear device, and more particularly to a gear device capable of suppressing backlash between a drive gear and a driven gear and a disk device using the gear device.

  2. Description of the Related Art Conventionally, a gear device is used to transmit the rotational motion of a rotational shaft to another rotational shaft by decelerating or accelerating it, or to convert the rotational motion of the rotational shaft into linear motion or the like. In such a gear device, when the rotational motion of the rotating shaft is reduced or accelerated, a driving gear and a driven gear meshing with the driving gear are used. In addition, when converting rotational motion into linear motion, the rack is meshed with the pinion gear.

  In general, when a pair of gears smoothly and smoothly rotate, a backlash is required between the gears. Backlash is a play (gap) between gears when a pair of gears are engaged. The backlash between the pair of gears A and B depends on the direction to be measured, as in the example of the rack B and the pinion gear A shown in FIG. 1, the circumferential backlash jt, the normal backlash jn, the center distance backlash jr, Although it is classified into a rotational angle backlash jθ (°), the most commonly known backlash is a backlash jn in the normal direction.

  On the other hand, the demand for gears with small backlash is increasing due to the higher precision of machines. There are a static method and a dynamic method for reducing the backlash. The static method is a method in which the backlash of the gear pair is adjusted to be small and the gear is fixed at the position, and the dynamic method is by applying an urging force for removing the backlash, This is a method of always maintaining zero backlash.

  The static method (adjustment / fixation method) includes a method of adjusting and fixing the gear and a method of adjusting and fixing the center distance, and there are three methods depending on the combination of these methods. As a structure in which the gear can be adjusted without adjusting the center distance, a method of fixing the gear after adjusting the gear so as to reduce the backlash after meshing the gear at a fixed center distance is often used. In particular, for a spur gear, a method is used in which two gears are overlapped and one side is shifted in the rotational direction for adjustment.

  The dynamic method (backlash forced removal method) is a method that forcibly performs the static method described above, and uses a biasing force such as a spring. An example in which a backlash forced removal method is applied to a spur gear is disclosed in Patent Document 1. The device disclosed in Patent Document 1 relates to a pickup feeding device of an optical disk device, and for back-up of a meshing portion of a power transmission gear (gear is synonymous with a gear) for high-precision feeding of an optical pickup. It is eliminated by the aforementioned backlash forced removal method.

  More specifically, in the pickup feeding device of the optical disc player described in Patent Document 1, two of the three gears constituting the pinion gear are driven by the force of the spring in the reverse direction. Are engaged with each other without causing backlash, and one of the two gears is engaged with the other gear without causing backlash by the biasing force of the spring in the reverse direction.

Japanese Utility Model Publication No. 5-21717 (FIGS. 2, 3, and 4)

However, the method for forcibly removing backlash disclosed in Patent Document 1 has the following problems.
(1) Due to the bias in one direction by the spring, in the forward / reverse rotation mechanism, the driving force is transmitted through the gear biased with respect to either rotation. In this case, the backlash is zero. (Actually only works in one direction of rotation).
(2) To accommodate both forward and reverse rotations, another set of gears biased in opposite directions is required.
(3) Since a bias mechanism and a bias gear are required, to apply this mechanism to all meshing gears, at least two parts are required for each meshing position, which complicates, increases costs, and deteriorates assembly. Invite.

  Therefore, the present invention can reduce the backlash in both forward and reverse rotations of the gear without greatly changing the original gear mechanism, has a simple structure, is compact, has a small number of parts, and can be easily installed. It is an object of the present invention to provide a gear device capable of achieving the above and a disk device using the gear device.

  A first embodiment of the gear device of the present invention that achieves the above object is a gear device that transmits a driving force of a driving gear attached to a driving shaft to a driven gear, wherein the number of teeth is larger than the number of teeth of the driving gear. One sub gear is rotatably attached to the drive shaft and frictionally coupled to the drive gear, and both the drive gear and the sub gear are meshed with the driven gear.

  A second form of the gear device of the present invention that achieves the above object is a gear device that transmits the driving force of the drive gear to the driven gear attached to the driven shaft, and the number of teeth is larger than the number of teeth of the driven gear. The auxiliary gear having a larger number is attached to the driven shaft so as to be rotatable and frictionally coupled to the driven gear, and both the driven gear and the auxiliary gear are engaged with the drive gear.

  Furthermore, the disc device of the present invention that achieves the above object is a gear device that transmits power of the disc transport mechanism, the turntable, and the pickup device in the disc device including the disc transport mechanism, the turntable, and the pickup device. The gear device of the first embodiment or the second embodiment of the gear device of the present invention is used.

  According to the present invention, the backlash can be reduced to 0 in both forward and reverse rotations without largely changing the original mechanism of the gear device, the structure is simple, compact, the number of parts is small, and the gear can be easily installed. An apparatus can be provided. In the following description, the gear may be referred to as a gear, but the gear and the gear are synonymous.

  Hereinafter, embodiments of the present invention will be described in detail based on specific examples with reference to the accompanying drawings. Before describing embodiments of the present invention, backlash in a spur gear of a conventional gear device will be described. Will be described with reference to FIGS. 2A to 2D for comparison with the gear device of the present invention.

  FIG. 2A is a perspective view showing a configuration of a gear device 9 using a conventional spur gear. In this figure, the drive gear 1 is attached to the drive shaft 3 and the driven shaft 4 is engaged with the drive gear 1. The driven gear 2 is shown. (B) is a top view of the gear apparatus 9 shown to (a), (c) is a front view of the gear apparatus 9 shown to (a). And (d) expands the broken-line part of (c) partially.

  In the conventional gear device 9 configured as described above, when the driving gear 1 rotates in the direction indicated by the arrow R and the driven gear 2 meshing with the rotating gear rotates in the direction indicated by the arrow L, as shown in FIG. In addition, a backlash J occurs between the tooth surface 1T2 of the drive gear 1 and the tooth surface 2T2 of the driven gear 2. That is, when the drive gear 1 rotates in the direction indicated by the arrow R and the tooth surface 1T1 of the drive gear 1 contacts the tooth surface 2T1 of the driven gear 2, the drive gear 1 and the driven gear 2 are adjacent to each other on the opposite side of the rotation direction. The backlash J is generated between the tooth surface 1T2 of the driving gear 1 and the tooth surface 2T2 of the driven gear 2. When such a backlash J is present, problems such as a collision noise being generated when the drive gear 1 is reversed and a delay in the operation of the driven gear 2 occur.

  FIGS. 3A to 3D show the configuration of a gear device 10 using a spur gear according to an embodiment of the present invention. FIG. 3A is a perspective view of the gear device 10 and FIG. ) Is a plan view of the gear device 10, (c) is a front view of the gear device 10 of (a), and (d) is a partially enlarged view of the broken line portion of (c). In addition, in the structure of the gear apparatus 10 of this invention, the same code | symbol is attached | subjected about the same member as the member used for the conventional gear apparatus 9. FIG.

  As shown in FIGS. 3 (a) and 3 (b), in the gear device 10 of this embodiment, the configuration of the drive shaft 3 and the driven shaft 4 is exactly the same as in the prior art. 2 is rotatably mounted. On the other hand, a friction gear 5 is attached to the drive shaft 3 as an auxiliary gear with a small plate thickness so as to be rotatable with respect to the drive shaft 3 and meshed with the driven gear 2. Further, the same drive gear 1 as the drive gear 1 used in the conventional gear device 9 is attached to the drive shaft 3 in a state where it is frictionally coupled to the friction gear 5 and meshed with the driven gear 2. .

  As shown in FIGS. 4A to 4C, the friction gear 5 can be formed of a material having a small plate thickness and a large friction coefficient. Such a friction gear 5 can be formed, for example, by punching a plate material of a spring with a press. In this embodiment, three protrusions 6 having the same height are provided on the concentric circles of the surface of the friction gear 5 facing the drive gear 1. The number of protrusions 6 is the same as that of the friction gear 5 and the drive gear 1. It is only necessary to obtain friction between them, and the number is not limited to three. Furthermore, in this embodiment, when the number of teeth of the drive gear 1 is N, the number of teeth of the friction gear 5 of this embodiment is (N-1). For example, when the number of teeth of the drive gear 1 is 28, the number of teeth of the friction gear 5 is 27.

  As shown by a broken line in FIG. 4E, the friction gear 5 is attached to the drive shaft 3 in a state of being meshed with a driven gear (not shown), and the drive gear 1 is fitted and fixed to the drive shaft 3. As shown in FIG. 4D, the friction gear 5 is curved as shown by a broken line in FIG. 4E when the friction gear 5 is slightly overlapped when fastened by the E-ring 7. . As a result, the friction gear 5 is installed so as to be biased with respect to the drive gear 1, and the frictional force indicated by the white arrow between the friction gear 5 and the drive gear 1 as shown in FIG. Occurs.

  When the gear device 10 configured as described above is viewed from the front, the drive gear 1 has N teeth (N = 28 in this embodiment) and the friction gear 5 has (N-1) teeth (this embodiment). In the case of N-1 = 27 in the example, as shown in FIG. 3C, the drive gear 1 and the friction gear 5 are engaged with the driven gear 2 and the teeth of the drive gear 1 are engaged. The teeth of the friction gear 5 gradually shift. This is because the tooth width of the friction gear 5 having a smaller number of teeth is larger than the tooth width of the drive gear 1. FIG. 3D is a partially enlarged view of the broken line portion of FIG.

  Here, the operation of the gear device 10 configured as described above will be described. When the drive gear 1 rotates in the direction indicated by the arrow R, the friction gear 5 also rotates in the direction indicated by the arrow R by the frictional force with the drive gear 1. As the drive gear 1 and the friction gear 5 rotate, the friction gear 5 has fewer teeth than the drive gear 1, so that the teeth appear to rotate slowly. That is, the rotation angle at which one tooth moves in the drive gear 1 is 360 ° / N, whereas the rotation angle at which one tooth moves is as large as 360 ° / (N−1).

  As a result, as shown in FIG. 3 (d), the tooth surface 5T2 of the friction gear 5 is delayed with respect to the backlash J generated between the drive gear 1 and the driven gear 2, thereby causing the drive gear 1 and the driven gear 2 to move. The clearance corresponding to the backlash J is zeroed by the friction gear 5.

  Here, for example, consider a case where the rotation of the driven gear 2 that rotates in the direction indicated by the arrow L becomes faster than the rotation of the drive gear 1. Before the rotation of the driven gear 2 becomes faster than the rotation of the drive gear 1, both the tooth surface 1T1 of the drive gear 1 and the tooth surface 25T1 of the friction gear 25 contact the tooth surface 2T1 of the driven gear 2 at a point H. ing.

  When the rotation of the driven gear 2 becomes faster than the rotation of the drive gear 1, the tooth surface 2T2 of the driven gear 2 tries to push the tooth surface 1T1 of the drive gear 1. In this state, the tooth surface 5T2 of the friction gear 5 Since it contacts the tooth surface 2T2 of the driven gear 2, the tooth surface 5T2 of the friction gear 5 is pushed by the tooth surface 2T2 of the driven gear 2 and rotates. At this time, since the friction gear 5 is coupled to the drive gear 1 by a frictional force, the frictional force counteracts the rotation of the driven gear 2 and suppresses the occurrence of backlash. Due to this action, it is possible to reduce the operating noise due to backlash. The operation of the friction gear 5 is the same when the rotation of the drive gear 1 is reversed. The same applies when the driven gear 2 is a rack.

  FIGS. 5A to 5C show another embodiment of the friction gear 5. As shown in FIGS. 5 (a) to 5 (c), the friction gear 5 can be processed into a curved friction gear 5A from the beginning by punching a thin plate material of a spring with a press. In this embodiment, a mounting auxiliary hole 8A having a diameter larger than that of the mounting hole 8 is provided beside the mounting hole 8 provided in the friction gear 5A.

  In this embodiment, when the friction gear 5A is attached to the drive shaft 3, as shown in FIGS. 5D and 5E, first, the drive gear 1 is fixed to the drive shaft 3, and then the friction gear is fixed. 5A is inserted through the drive shaft 3 through the auxiliary hole 8A so that the concave surface is on the drive gear 1 side. Next, the mounting hole 8 is fitted into the circumferential groove 3 </ b> A provided at the tip of the drive shaft 3 by sliding the friction gear 5 </ b> A while pushing the center. Then, the friction gear 5A is frictionally coupled by pressing the outer peripheral portion of the friction gear 5A against the drive gear 1 as shown in FIG. The operation of the friction gear 5A is the same as that of the friction gear 5 described above.

In order to generate a frictional force between the friction gear 5 and the drive gear 1, the following method can be considered in addition to using the spring material for the friction gear 5 as described above.
(1) Use adhesive grease between the friction gear 5 and the drive gear 1 (2) Make the friction gear 5 and the drive gear 1 with a material having a large coefficient of friction (3) Use sheet material (If soft material is used, it is possible to reduce the impact noise caused by backlash and control the sound quality of the impact sound)

  The gear device 10 configured as described above can be used, for example, in a drive mechanism 12 of a pickup device 11 of a disk device as shown in FIG. The pickup device 11 includes a turntable 14 for rotating a disk (not shown) at the tip of a swing arm 13 and a pickup 15 for irradiating the disk with a laser beam. The pickup 15 is driven by a drive mechanism 12. A rotating drive shaft 16 moves on the guide shaft 17.

  An enlarged perspective view of the drive mechanism 12 of the pickup device 11 is shown in FIG. 6B, and an enlarged plan view is shown in FIG. 6B. The drive mechanism 12 includes the above-described gear device 10 including the drive gear 1, the friction gear 5, and the driven gear 2. When the driving force from a motor (not shown) is transmitted to the gear device 10, the driven gear 2 is driven. Then, the drive shaft 16 is driven by the subsequent gear train.

  FIG. 7 (a) shows a configuration of a gear device 20 using a spur gear according to another embodiment of the present invention, and FIG. 7 (b) shows a partially broken line portion of the gear device 20 shown in FIG. It is an enlarged one. In the above-described embodiment, the power is transmitted from the drive gear 1 having a large number of teeth to the driven gear 2 having a small number of teeth. However, this embodiment is a drive having a small number of teeth attached to the drive shaft 24. Power is transmitted from the gear 21 to the driven gear 22 having a small number of teeth attached to the driven shaft 23, and the friction gear 25 is attached in a state of being frictionally coupled to the driven gear 22. In this case, the number of teeth of the friction gear 25 is one more than the number of teeth of the driven gear 22.

  When the gear device 20 of this embodiment is viewed from the front, the number of teeth of the driven gear 22 is N (N = 27 in this embodiment), and the number of teeth of the friction gear 25 is (N + 1) (N + 1 = 28 in this embodiment). 7), as shown in FIG. 7A, the teeth of the friction gear 25 are compared to the teeth of the driven gear 22 in a state where the driven gear 22 and the friction gear 25 are both engaged with the drive gear 21. It gradually shifts. This is because the tooth width of the driven gear 22 having a smaller number of teeth is larger than the tooth width of the friction gear 25.

  Here, operation | movement of the gear apparatus 20 comprised as mentioned above is demonstrated. When the drive gear 21 rotates in the direction indicated by the arrow L, the driven gear 22 rotates in the direction indicated by the arrow R, and the friction gear 25 also rotates in the direction indicated by the arrow R by the frictional force with the driven gear 22. As the driven gear 22 and the friction gear 25 rotate, the friction gear 25 has one more tooth than the driven gear 22, so that the teeth rotate apparently faster. That is, the rotation angle of the driven gear 22 at which one tooth moves is 360 degrees / N, whereas the rotation angle of the friction gear 25 at which one tooth moves is as small as 360 degrees / (N + 1).

  As a result, as shown in FIG. 7B, the tooth surface 25T2 of the friction gear 25 advances with respect to the backlash J generated between the drive gear 21 and the driven gear 22, whereby the drive gear 21 and the driven gear 22 are moved. The clearance corresponding to the backlash J is zeroed by the friction gear 25.

  Here, for example, consider a case where the rotation of the driven gear 22 that rotates in the direction indicated by the arrow R becomes faster than the rotation of the drive gear 21. Before the driven gear 22 rotates faster than the drive gear 21, the tooth surface 21T1 of the drive gear 21 contacts both the tooth surface 22T1 of the driven gear 22 and the tooth surface 25T1 of the friction gear 25 at point H. ing.

  When the rotation of the driven gear 22 becomes faster than the rotation of the driving gear 21, the tooth surface 22T2 of the driven gear 22 tries to push the tooth surface 21T2 of the driving gear 21. In this state, the tooth surface 25T2 of the friction gear 25 Is in contact with the tooth surface 21T2 of the drive gear 21, the tooth surface 25T2 of the friction gear 25 is pushed by the tooth surface 21T2 of the drive gear 21 to rotate. At this time, since the friction gear 25 is coupled to the driven gear 22 by a frictional force, the frictional force counteracts the rotation of the drive gear 21 and suppresses the occurrence of backlash. Due to this action, it is possible to reduce the operating noise due to backlash. The operation of the friction gear 25 is the same when the rotation of the drive gear 21 is reversed. The same applies when the drive gear 21 or the driven gear 2 is a rack.

  In the first embodiment described above, the number of teeth of the friction gear 5 superimposed on the drive gear 1 is 27, which is one less than the number of teeth 28 of the drive gear 1, and in the next embodiment, The case where the number of teeth of the friction gear 25 superimposed on the driven gear 22 with respect to the number of teeth 27 of the driven gear 22 is one more than this has been described. However, the difference in the number of teeth from the drive gear of the friction gear superimposed on the drive gear or the difference in the number of teeth from the driven gear of the friction gear superimposed on the driven gear is caused by the backlash caused by the meshing of the drive gear and the driven gear. What is necessary is just to change suitably according to a magnitude | size, and the difference in the number of teeth is not limited to one.

  FIG. 8A shows a configuration of a disk device 40 including a disk changer to which the gear device of the present invention can be applied, and shows a state where no disk is accommodated. FIG. 8B shows the internal configuration of the disk device 40 shown in FIG. A disk device 40 to which the present invention is applied includes a stocker 41 that can house a plurality of disks inside the device main body and can move up and down in the device, take out the disk from the stocker 41, reproduce the removed disk, and A swing arm 43 for returning the reproduced disc to the stocker 41, a drive device 47 for the swing arm 43, a linear position sensor (not shown) for detecting the position of the stocker 41, and the linear position sensor An elevating mechanism 45 that elevates and lowers the stocker 41 based on the output is provided.

  The swing arm 43 is rotated by a driving device 47 and is roughly composed of a frame 30 and a clamp arm 33. A turntable 32 for rotating the disk is provided at the tip of the frame 30, and an optical head 36 and a moving path 35 through which the optical head 36 moves are provided at the center of the frame 30. The base of the clamp arm 33 is attached to the frame 30 by a rotary shaft, and a clamper 34 is rotatably provided at the tip of the clamp arm 33. The tip of the clamp arm 33 rotates to the frame 30 side, and the disk placed on the turntable 32 is clamped by the clamper 34 and fixed.

  The position of the swing arm 3 in the vertical direction remains constant. Therefore, in order for the swing arm 43 to clamp a desired one of the disks stored in the stocker 41, the stocker 41 is divided and moved in the vertical direction of the apparatus. The stocker 41 includes a single stocker base and a plurality of movable stockers mounted thereon, and each movable stocker can store one disk. The stocker 41 is moved up and down in the apparatus by a lifting mechanism 45 of the stocker. Further, in order to take out a desired single disk held by the stocker 41 by the swing arm 43, the movable stocker constituting the stocker 41 can be divided vertically at a desired position by the separation mechanism 46 of the stocker. ing.

  A disk pushing mechanism 90 for pushing out one disk stored in the stocker 41 is provided in the housing of the disk device 40 on the back side of the stocker 41 having a plurality of movable stockers. The height of the disc pushing mechanism 90 from the bottom surface of the disc device 40 is fixed, and the disc in the movable stocker at a predetermined position is moved by the disc pushing mechanism 90 to the disc ejection position by moving the stocker 41 in the vertical direction. To extrude. The disc pushed to the disc ejection position is ejected from the disc insertion / ejection port 42 of the disc device 40 by the disc insertion / ejection mechanism 44 (details are not shown). The disk guide device used in the disk device 40 is a device that reliably guides the disk to the disk insertion / ejection mechanism when the disk is pushed out to the disk ejection position by the pushing mechanism. / It is provided in a part adjacent to the discharge port 42.

  Next, the operation of the disk when the disk is ejected in the disk device 40 will be described with reference to FIG. 8B together with the disk 27 in the disk device 40, the stocker 41 that houses the disk 27, and the drive mechanism 80 of the operation lever 70. . FIG. 8B shows the state of the disk device 40 during the start of the pushing operation, and the disk 27 is pushed out by the disk pushing mechanism 90. The drive mechanism 80 of the operation lever 70 includes a drive motor 81 and a gear device 82.

  The disk push-out mechanism 90 of this embodiment is composed of a first lever part 50 and a second lever part 60, and the first lever part 50 is located in the vicinity of the rotation axis of the second lever part 60. Thus, the operation lever 70 starts to rotate before the second lever portion 60 is operated. The first lever portion 50 has a tapered wedge-shaped lever 54. The disc pushing mechanism 90 does not have to include both the first and second lever portions 50 and 60 as described above, and the second lever portion 60 is sufficient.

  The operation lever 70 that operates the disk push-out mechanism 90 includes a main body portion 71, an operation input portion 72, an operation output portion 73, and a guide groove 74. The operation input unit 72 of the operation lever 70 is connected to the drive mechanism 80, and the operation lever 70 is pulled in the direction of the arrow A in the drawing by the operation of the drive mechanism 80, or is returned in the direction opposite to the arrow A. Or When the operating lever 70 moves in the direction of the arrow A, the pushing lever 64 of the second lever portion 60 rotates following the wedge-shaped lever 54 of the first lever portion 50, and the above-described movable movement secured by the wedge-shaped lever 54. The disc 27 inserted in the space between the stocker and the movable stocker and held by the upper movable stocker is pushed out. The pushing lever 64 of the second lever portion 60 rotates together with the wedge-shaped lever 54 when it catches up with the wedge-shaped lever 54 of the first lever portion 50.

  When the disk 27 held by the stocker 41 is pushed out by the rotation of the pushing lever 64 and reaches the disk ejection position, the disk 27 is ejected from the disk device 40 by the disk insertion / ejection mechanism 44. A rotating roller for moving the disk 27 is provided inside the disk insertion / ejection mechanism 44. Inside the insertion / ejection mechanism 44 is a motor and a gear device for rotating the roller.

  The gear device of the present invention is a gear device for transmitting the driving force of a motor, such as a disc insertion / ejection mechanism, a turntable, a swing arm drive mechanism having a pickup device, a drive lever drive mechanism, etc. as described above. Can be used for the gear device.

It is explanatory drawing which shows the kind and direction of backlash in a pair of gear which meshed | engaged. (A) is a perspective view showing a configuration of a conventional gear device using a spur gear, (b) is a plan view of the gear device shown in (a), and (c) is a front view of the gear device shown in (a). FIG. 4D is a partially enlarged view of the broken line part of FIG. (A) is a perspective view which shows the structure of the gear apparatus using the spur gear of one Example of this invention, (b) is a top view of the gear apparatus shown to (a), (c) is shown to (a). The front view of a gear apparatus, (d) is the elements on larger scale of the broken-line part of (c). (A) is the perspective view which shows the structure of one Example of the friction gear used for the gear apparatus using the spur gear of one Example of this invention shown in FIG. 3, (b) was shown to (a). The side view of a friction gear, (c) is a front view of the friction gear shown in (a), (d) is the perspective view of the drive gear which attached the friction gear of the composition shown in (a)-(c), (e) ) Is a plan view of (d). (A) is a perspective view which shows the structure of another Example of the friction gear used for the gear apparatus using the spur gear of one Example of this invention shown in FIG. 3, (b) is shown to (a). (C) is a front view of the friction gear shown in (a), (d) is a perspective view of a drive gear to which the friction gear having the configuration shown in (a) to (c) is attached, e) is a plan view of (d). (A) is a perspective view of the optical pick-up apparatus in which the gear apparatus of this invention is used, (b) is the elements on larger scale of the broken-line part of (a), (c) is a top view of (b). (A) is a front view which shows the structure of the gear apparatus using the spur gear of another Example of this invention, (b) is the elements on larger scale of the broken-line part of the gear apparatus shown to (a). (A) is a perspective view which shows the structure of the disc apparatus which can use the gear apparatus of this invention, (b) is a top view which shows the internal structure of the disc apparatus shown to (a).

Explanation of symbols

1, 21 Drive gear 2, 22 Drive gear 3, 23 Drive shaft 4, 24 Drive shaft 5, 25 Friction gear 6 Projection 10, 20 Gear device of the present invention 11 Pickup device 27 Disc 44 Insertion / ejection mechanism 81 Motor 82 Gear device

Claims (9)

A gear device for transmitting a driving force of a driving gear attached to a driving shaft to a driven gear,
A sub gear having one tooth number smaller than the number of teeth of the drive gear is attached to the drive shaft so as to be rotatable and frictionally coupled to the drive gear;
A gear device characterized in that both the drive gear and the auxiliary gear mesh with the driven gear.   The side surface of the auxiliary gear on the drive gear side is provided with a protrusion, and the auxiliary gear is attached to the drive gear in a state where the protrusion is in contact with the auxiliary gear. Gear device.   The auxiliary gear is formed in a curved shape using a spring material, and the auxiliary gear is attached in a biased state with the concave side of the curved shape facing the drive gear. The gear device according to claim 1. A gear device for transmitting a driving force of a driving gear to a driven gear attached to a driven shaft,
An auxiliary gear having one tooth number larger than the number of teeth of the driven gear is attached to the driven shaft so as to be rotatable and frictionally coupled to the driven gear;
A gear device characterized in that both the driven gear and the auxiliary gear mesh with the drive gear.   5. A projection is provided on a side surface of the auxiliary gear on the driven gear side, and the auxiliary gear is attached to the driven gear with the projection in contact therewith. Gear device.   The auxiliary gear is formed in a curved shape using a spring material, and the auxiliary gear is attached in a biased state with the concave side of the curved shape facing the driven gear. The gear device according to claim 4.   The gear device according to any one of claims 1 to 6, wherein the auxiliary gear is formed of a material having a large friction coefficient.   The gear device according to any one of claims 1 to 7, wherein the driving gear or the driven gear is a rack. A disk device comprising a disk transport mechanism, a turntable, and a pickup device,
A disk device using the gear device according to any one of claims 1 to 8 as a gear device for transmitting power of the disk transport mechanism, the turntable, and the pickup device.

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