JP5728792B2 - Gear mechanism - Google Patents

Description

The present invention relates to a gear mechanism of a gear transmission device of a machine tool.

  2. Description of the Related Art Conventionally, with the progress of composite machine tools, a rotary table for placing or fixing a workpiece or a tool spindle to which a tool is attached has an indexing function in addition to rotation. Such machine tools require indexing accuracy. Since the indexing is transmitted from the drive shaft to the rotary table shaft and the tool spindle through a plurality of gears, the indexing accuracy is reduced due to backlash by the gears.

  Therefore, in order to reduce the backlash, the cited reference 1 (FIG. 3) uses a backlash adjusting device 81 as shown in FIG. This backlash adjusting device is for driving the turning table 2, and the driving drive is provided with a helical gear 91 on the drive shaft 90. The driving is a first helical gear 92 meshing with the helical gear, The first helical gear coaxially with the first helical gear is provided with a second helical gear 94 whose helical direction is reverse (reverse twist), and the first intermediate shaft 85 To do.

  In addition to the first helical gear 92, the driving helical gear 91, the third helical gear 95 that meshes with the third helical gear 92, and the third helical gear coaxially with the third helical gear. A fourth helical gear 97 having a reverse helical direction is provided as a second intermediate shaft 86. The second and fourth helical gears 94 and 97 are simultaneously meshed with the helical gear 18 driven by the table rotating shaft 6c. Further, the backlash between the driven helical gear 18 and the driven helical gear 91 is adjusted by moving at least one of the first or second intermediate shafts 85 and 86 in the axial direction.

  Further, in Patent Document 2 (FIG. 1), as shown in FIG. 7, the gear meshing with the drive gear 91 is a spur gear instead of a helical gear, and the drive shaft 90 is moved in the axial direction, thereby indexing. And being able to switch between high-speed rotation. In addition, the same code | symbol is attached | subjected to the structure similar to patent document 1, and description is abbreviate | omitted. Further, there is no particular disclosure regarding the adjustment mechanism or method.

  However, in such a conventional one, the moving second or fourth helical gears 94 and 97 and the driven helical gear 18 move in the axial direction and the tooth surfaces contact each other in the tooth width direction. Since a non-contact portion occurs, uneven wear and vibration may occur. Further, since the driven gear is generally large, fine adjustment and accuracy are required.

  On the other hand, in the turning table 2 of Patent Document 3 (FIG. 4), the drive shaft 87 is moved without moving the first and second intermediate shafts 85 and 86, as shown in FIG. In the backlash adjusting device 81 of Patent Document 3, a set of helical drive gears 91 and 93 having a reverse twisting direction are provided on the drive shaft 87, and the lower drive meshes with the helical gear 91 as seen in the figure. The helical gear 92 and the first helical gear coaxially with the first helical gear include a second helical gear 94 whose helical direction is opposite (reverse twist). The first intermediate shaft 85 is provided.

  In addition to the first helical gear 92, as shown in the figure, a third helical gear 94 that engages with the upper helical gear 93 and a third helical gear 94 that engages with the third helical gear are arranged coaxially. The third helical gear is provided as a second intermediate shaft 86 by providing a fourth helical gear 97 having the same helical direction. The second and fourth helical gears 94 and 97 are engaged with the helical gear 18 at the same time as the follower of the table rotation shaft. Further, the backlash between the driven helical gear and the drive gear is adjusted by moving the drive shaft 87 in the axial direction. A drive gear 98 is provided on the drive shaft 87 so as to mesh with the gear 99 of the output shaft 90 of the drive motor 8.

JP 2008-106894 A JP-A-8-90377 JP-A-8-197366

However, in the case of Patent Document 3, there is no axial movement of the tooth surface by the helical gear 18, but the drive motor 8 and the drive shaft 87 are connected by the gears 99, 98. Backlash between the shafts 87 occurs. For this reason, when the rotation direction of the drive motor is reversed, there is a problem that backlash occurs and indexing accuracy is lowered. Further, even if the drive shaft 87 and the drive motor shaft 90 are integrated, there is a problem that the structure becomes complicated. In addition, there is a problem that the number of gears in the axial direction is as large as four and the height in the axial direction is increased. In view of such a problem, the object of the present invention is to avoid the axial movement of the gear meshing with the driven helical gear, and there is no backlash even if the drive motor is reversed, the number of axial steps is small, and the structure is simple. It is to provide a small gear mechanism .

According to the present invention, in the gear drive device for the rotary shaft of the machine tool , the first helical gear meshes with the servomotor and the drive helical gear provided on the drive shaft of the servomotor, and the drive is one of the helical gears. A helical gear, a first intermediate shaft provided with a second helical gear that is reversely twisted with the first helical gear, coaxially with the first helical gear, and the second helical gear. A first intermediate helical gear meshing with a helical gear; a second intermediate helical gear meshing with the other helical gear; and a second intermediate meshing with a helical gear. A helical gear, and a second intermediate shaft provided with the third helical gear and a fourth helical gear, which is reversely twisted, coaxially with the third helical gear. The first intermediate helical gear and the fourth helical gear mesh with the driven helical gear provided on the rotating shaft at the same time. Been further by moving the first intermediate shaft in the axial direction, the driven the drive is a helical gear indexing consists backlash adjusting device capable adjust backlash between helical gear A gear drive device, and a spindle motor and a drive gear shaft separate from the output shaft of the spindle motor are flat belted between the output shaft and the drive gear shaft opposite to the flat belt. The high-speed drive provided is a helical gear, the high-speed drive is a first reduction helical gear meshing with the helical gear, and the first reduction helical gear is opposite in twisting direction. A first small helical gear provided on the upper side of the coaxial axis, a second reduction helical gear meshing with the first small helical gear, and the second reduction gear. The helical gear and twist direction are opposite A second small helical gear provided on the lower side of the coaxial axis; a third reduction helical gear meshing with the second small helical gear; and the third reduction helical gear. A gear mechanism comprising a high-speed rotating gear driving device comprising a multi-stage gear device having a helical gear for high-speed rotation provided on the upper side of the same axis and having a reverse twisting direction to that of the gear. A clutch mechanism capable of connecting or disconnecting the drive shaft of the helical gear and the servo motor shaft is provided between the helical gear and the servo motor, and the driven gear of the helical gear is provided. The rotating shaft is a rotating shaft for a work table on which a workpiece is placed, and the driven helical gear meshes with the helical gear for high-speed rotation as described above by providing a gear mechanism . Solved the problem.

That is, the intermediate shaft that moves in the axial direction that adjusts the backlash between the driving helical gear and the driven helical gear is the first intermediate shaft that meshes with the driving helical gear, and the first intermediate shaft and the driven helical gear. A first intermediate helical gear was provided between the gears. As a result, even if the first intermediate shaft moves in the axial direction, the driven helical gear does not come into contact with the second helical gear that moves, and therefore, wear and extra uneven load are less likely to occur. The second intermediate helical gear matches the number of gears between the driving gear and the driven helical gear. Also, the number of gears in the axial direction can be made two. Since the gear mechanism using the helical gear is suitable for a table that needs to be indexed with high accuracy, such as a table for attaching a workpiece, the driven shaft of the gear mechanism is mounted on the rotating shaft of the helical gear. A rotating shaft for worktable was used. Further, in order to be able to be used at high speed rotation instead of indexing, the driven helical gear is meshed with the high speed rotation shaft, and the drive is connected to or disconnected from the drive shaft of the helical gear. A possible clutch mechanism was provided.

Since the second intermediate helical gear matches the number of gears between the driving helical gear and the driven helical gear, the driving intermediate gear is replaced between the helical gear and the second intermediate shaft. The second intermediate shaft and the driven member may be provided between the helical gears. Therefore, according to the second aspect of the present invention, in the gear drive device for the rotary shaft of the machine tool, the servomotor and the drive helical gear provided on the drive shaft of the servomotor and the drive is one of the helical gears. A first helical gear meshing with the first helical gear, a first intermediate shaft provided with a second helical gear coaxially and reversely twisted with the first helical gear, and the second helical gear. A first intermediate helical gear meshing with the gear, a fifth helical gear meshing with the other helical gear, and a sixth helical gear that is reversely twisted coaxially with the fifth helical gear. A third intermediate shaft provided with a helical gear, and a third intermediate helical gear meshing with the sixth helical gear, wherein the first intermediate helical gear and the first intermediate gear The intermediate gear 3 is configured such that a helical gear provided on the rotary shaft is simultaneously meshed with the helical gear, and the first gear By moving between shaft in the axial direction, the driven the drive is a helical gear is adjustable and the backlash adjusting device indexing gear drive consists of a backlash between the helical gear, and, the spindle motor and A drive gear shaft separate from the output shaft of the spindle motor is hung with a flat belt between the output shaft and the high-speed drive provided on the opposite side of the drive gear shaft from the flat belt is a subwoofer. The first reduction helical gear that meshes with the gear, the high-speed drive helical gear, and the first reduction helical gear are opposite to each other in twisting direction, and are provided on the coaxial upper side. The first small helical gear, the second reduction helical gear meshing with the first small helical gear, and the second reduction helical gear are opposite in twisting direction. Yes, the second provided coaxially The small helical gear, the third reduction helical gear meshing with the second small helical gear, and the third reduction helical gear are opposite in twisting direction. A gear mechanism having a high-speed rotating gear drive device comprising a multi-stage gear device having a high-speed rotating helical gear provided on the upper side of the coaxial shaft, wherein the driving is performed between the helical gear and the servo motor. A clutch mechanism capable of connecting or disconnecting the drive shaft of the helical gear and the servo motor shaft is provided in between, and the rotation shaft of the driven helical gear is a work table on which a work is placed. The gear mechanism is characterized in that the driven helical gear meshes with the high-speed rotating helical gear .

  Further, in order to make the entire meshing smooth, all are helical gears, but functionally, the driven gear may be a spur gear if it is not directly related to the helical gear. Therefore, in the invention described in claim 3, the driving helical gear, the first helical gear, the second intermediate helical gear, and the third helical gear are spur gears. The second helical gear and the fourth helical gear have opposite twisting directions, and the fourth helical gear meshes with the driven gear.

  In the invention described in claim 4, the driving helical gear, the first helical gear, and the fifth helical gear are spur gears. The second helical gear and the third intermediate helical gear have opposite torsional directions, and the third intermediate helical gear meshes with the driven gear.

In the present invention, the first intermediate helical gear without axial movement is provided between the first intermediate shaft moving in the axial direction and the driven helical gear of the rotary shaft. As a result, even if the first intermediate shaft moves in the axial direction, the driven helical gear and the second helical gear that moves in the axial direction do not directly mesh with each other, thus causing wear and excessive offset load. The structure is simple by separating the drive shaft and the axial movement shaft. Further, since the number of stages in the axial direction of the gear can two stages, can be a small low height (claim 1乃optimum 4). Furthermore, since all are helical gears, the meshing is smooth and high indexing accuracy can be obtained. In addition, a simple work table with a structure with low backlash and high work indexing accuracy is provided, and the indexing motor can be separated by the clutch mechanism and connected to the motor for high speed rotation. It can be applied to multi-task machine tools. (Claims 1 and 2).

In the invention described in claim 3, the driving helical gear, the first helical gear, the second intermediate helical gear, and the third helical gear are spur gears, In the invention described in claim 4, since the driving helical gear, the first helical gear, and the fifth helical gear are spur gears, the axial load of the driving shaft can be reduced. Simple .

It is a model perspective view of the gear mechanism which shows 1st embodiment of this invention. It is a plane schematic diagram of the work table showing the first embodiment of the present invention. It is the sectional view on the AA line of FIG. It is a model perspective view of the gear mechanism which shows 2nd embodiment of this invention. It is a model perspective view of the gear mechanism which shows 3rd embodiment of this invention. It is a model perspective view of the conventional helical gear mechanism. FIG. 6 is a schematic perspective view of a conventional helical gear mechanism. It is a model perspective view of the conventional helical gear mechanism.

A first embodiment of the present invention will be described with reference to the drawings. In the first embodiment, a case where helical gears are used for all the gears of the backlash adjusting device constituting the gear mechanism is shown. As shown in FIGS. 1 to 3, the gear mechanism of the present invention is used for an indexing gear drive device 3 of a work table 2 on which a work (not shown) is placed. The work table 2 is selectively driven with an indexing gear driving device 3 and a high-speed rotating gear driving device 4, and has two types of high-precision indexing and high-speed rotation (generally 300 rpm or less for a table). Rotation can be obtained.

The work table 2 is rotatable around a fixed shaft 6 via a cross roller bearing 7 on a fixed shaft 6 provided on a base 5. The work (rotation) table upper surface 2 a is a disk plane, and a right-handed driven helical gear 18 is provided concentrically with the fixed shaft 6 on the outer periphery 5 b of the lower surface. The indexing gear driving device 3 includes a servo motor 8 and a backlash adjusting device 1 that have high rotational indexing accuracy for indexing. A servo motor 8 is mounted downward on the base 5, is decelerated via a planetary reduction gear, and is further connected to a drive shaft 10 via a clutch mechanism 9 that is disconnected or connected by magnetism.

The drive shaft 10 is provided with a helical gear 11 for right-twist drive and is connected to a backlash adjusting device. The right-handed drive is such that one of the helical gears 11 and the first helically-twisted helical gear 12 are engaged. As shown in the figure, the first helical gear 12 is provided below the first intermediate shaft 21. On the upper side of the first intermediate shaft, a second helical gear 13 having a right-handed twist, which is reversely twisted from the first helical gear, is provided. Further, a first intermediate helical gear 14 is provided so as to mesh with the second helical gear 13, and the first intermediate helical gear 14 is driven by a right helical screw 18. To be engaged.

On the other hand, the right-handed drive is such that the second intermediate helical gear 15 is meshed with the left-handed second helical gear 15 on the other side of the helical gear 11, and the second intermediate helical gear 15 is further connected to the third right-twisted third gear. The helical gear 16 is engaged with the helical gear 16. As shown in the figure, the third helical gear 16 is fixed to the lower side of the second intermediate shaft 22, and the upper side of the second intermediate shaft is twisted counterclockwise to the third helical gear of right-handed twist. A fourth helical gear 17 having a left-hand twist is provided. Further, the left helical fourth helical gear 17 meshes with the helical gear 18 in the right helical follower. Note that the rotation shaft of each gear is parallel to the fixed shaft 6 (the same applies hereinafter).

  The first intermediate helical gear 14 and the fourth helical gear 17 are engaged with the driven helical gear 18 at the same time. Further, the first intermediate shaft 21 is provided with a hydraulic cylinder 24 so that the first intermediate shaft 21 can be moved in the axial direction. For example, when the first intermediate shaft is shifted in the direction of the arrow (downward) as seen in the figure, the first intermediate helical gear 12 receives a force in the clockwise direction. At the same time, the drive receives a force in the left rotation direction of the helical gear 11, and the driven can push back the tooth surfaces of the helical gear 18 to the opposite sides to eliminate or reduce backlash.

Thereby, high-precision indexing without backlash of the work table 2 by the servo motor 8 can be performed. Further, since being provided separately from the intermediate shaft 21 is helical gear 11 is driven servo motor 8 and clutch mechanism 9 is connected to move in the axial direction for backlash adjustment, the structure is simple. Further, the number of gears in the axial direction is two and the height dimension can be reduced.

On the other hand, the driven helical gear 18 further meshes with the helical gear 67 for high speed rotation. The high-speed rotating gear driving device 4 provided with the high-speed rotating helical gear 67 includes a high-speed rotating spindle motor 60 and a multi-stage gear device. The output shaft 60a of the spindle motor and the drive gear shaft 71 installed on the base 5 with the output shaft facing upward are transmitted by a flat belt 72 hook. The drive gear shaft 71 is supported by a bearing 74, and a high-speed drive helical gear 61 is provided on the opposite side (lower side in FIG. 3) of the flat belt pulley 73.

  The high speed drive helical gear 61 is engaged with the first reduction helical gear 62 having a higher number of teeth than the high speed drive helical gear. The first small helical gear 63 having the opposite twisting direction to the first reduction helical gear 62 and having a small number of teeth is coaxially aligned with the first reduction helical gear and the first high-speed intermediate shaft. 75 (as viewed in FIG. 3).

  The first small helical gear 63 is further engaged with a second reduction helical gear 64 having more teeth than the first small helical gear. The second small helical gear 65 having the opposite twisting direction to the second reduction helical gear 64 and having a small number of teeth is coaxially aligned with the second reduction helical gear, and the second high-speed intermediate shaft. 76 (as viewed in FIG. 3).

  The second small helical gear 65 is further engaged with a third reduction helical gear 66 having more teeth than the second small helical gear. A third high-speed intermediate shaft 77 is coaxially connected to the third reduction helical gear 67 so that the helical gear 67 for high-speed rotation with a reverse twist direction and a smaller number of teeth than the third reduction helical gear 66 is coaxial. It is provided on the upper side (as viewed in FIG. 3). The helical gear 67 for high speed rotation meshes with the driven helical gear 18 to rotate the work table 2 at high speed. A helical gear having an opposite torsional direction is disposed on the intermediate shaft to eliminate the generation of an axial load, and the size of the gears of the adjacent intermediate shafts is disposed in the reverse position to reduce the gear space.

According to the work table apparatus, in the case of indexing operations, connect the clutch mechanism 9, indexing of the work table 2 by the servo motor 8 via a backlash adjusting device 1 backlash-free indexing gear drive according to 3 Is performed with high accuracy. In this case, the high-speed rotating gear driving device 4 and the spindle motor 60 are rotated together, but at the time of indexing, the rotational speed (rotational speed) of the work table 2 is small, so that torque loss and vibration are small.

On the other hand, in the high speed rotation operation to release the clutch mechanism 9, by the action of the hydraulic cylinder 24 of the backlash adjusting device 1 in the opposite direction to move the first intermediate shaft 21 upward, giving a backlash. In this state, the spindle motor 60 is rotated, and the work table 2 is rotated at a desired rotational speed. The indexing gear driving device 3 is rotated with rotation, but the rotation of the work table is about 300 rpm, and the influence of vibration and torque loss is small. Further, since the backlash is applied, the frictional force for adjusting the backlash is reduced, and since it is separated from the servo motor, smooth rotation is possible. The first intermediate helical gear 14, the fourth helical gear 17, and the high-speed rotating helical gear 67 that mesh with the helical gear 18 of the driven table 2 for both indexing and high-speed rotation. Since there is no difference in the axial direction, the entire tooth surface is rotated uniformly, so that smooth indexing and rotation are ensured.

Next, a second embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 4, the backlash adjusting device according to the second embodiment of the present invention is obtained by changing the arrangement of the intermediate shaft. Note that parts similar to those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 4, the drive of the drive shaft 10 is engaged with the first helical gear 12, the first intermediate shaft 21, the second helical gear 13, and the first intermediate helical gear that mesh with the helical gear 11. The first intermediate helical gear 14 meshes with the driven helical gear 18. Further, the first intermediate shaft 21 is movable in the axial direction by a hydraulic cylinder 24. This is the same as in the first embodiment described above.

  In the second embodiment, the right-handed drive is engaged with the left-handed fifth helical gear 35 on the other side of the helical gear 11. In the figure, the left helical fifth helical gear 35 is fixed to the lower side of the third intermediate shaft 23, and the upper left side of the third intermediate shaft is a fifth helical gear having a left twist. A sixth helical gear 36 having a right-handed twist and a reverse twist is provided. Further, the sixth helical gear 36 that is right-hand-twisted is adapted to mesh with a third intermediate gear 37 that is left-hand-twisted. Further, the third intermediate helical gear 37 of left-handed twist is adapted to mesh with the helical gear 18 of right-handed follower.

  The first intermediate helical gear 14 and the third intermediate helical helical gear 37 are adapted to mesh with the driven helical gear 18 simultaneously. As described above, the backlash can be adjusted by shifting the first intermediate shaft 21 in the axial direction.

Next, a third embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 5, in the backlash adjusting device of the third embodiment of the present invention, the helical gear on the drive shaft side is a spur gear. Note that parts similar to those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 5, a drive spur gear 41 is provided on the drive shaft, and is connected to a backlash adjusting device. One of the drive spur gears 41 and the first spur gear 42 are engaged with each other. As seen in the figure, the first spur gear 42 is provided below the first intermediate shaft 51. A second helical gear 13 having a right twist is provided on the upper side of the first intermediate shaft.

  Further, as described above, a left-handed first intermediate helical gear 14 is provided so as to mesh with the right-handed second helical gear 13, and further, the first intermediate helical gear 14 is provided. The right-handed follower meshes with the helical gear 18.

  On the other hand, the second intermediate spur gear 45 is engaged with the other side of the drive spur gear 41, and the second intermediate spur gear 45 is further engaged with the third spur gear 46. As shown in the figure, the third spur gear 46 is fixed to the lower side of the second intermediate shaft 52, and the fourth helical gear 17 having a left-hand twist is provided on the upper side of the second intermediate shaft 52. Yes. Further, as described above, the left helical fourth helical gear 17 meshes with the helical gear 18 whose right helical follower.

  Even if the first intermediate helical gear 14 and the left helical fourth helical gear 17 are engaged with the driven helical gear 18 at the same time, and the drive side is a spur gear, the same as described above. Backlash can be eliminated or reduced by shifting one intermediate shaft.

Further, when the first intermediate helical gear 14 and the third intermediate helical gear 37 in FIG. 4 are engaged with both sides of the driven helical gear 18, the driving is the helical gear 11 and the first helical gear 11. If the helical gear 12 and the third helical gear 35 are respectively spur gears, it is possible to do so, and the description is omitted.

1 Backlash adjusting device 2 Work table 3 Indexing gear drive
4 high speed rotating gear drive
6 Fixed shaft 8 Servo motor 9 Clutch mechanism 10 Drive shaft 11 Drive helical gear 12 First helical gear 13 Second helical gear 14 First intermediate helical gear 15 Second intermediate helical Helical gear 16 third helical gear 17 fourth helical gear 18 driven helical gear 21 first intermediate shaft 22 second intermediate shaft 23 third intermediate shaft 35 fifth helical gear 36 sixth helical gear 37 third intermediate helical gear 41 drive spur gear 42 first spur gear 45 second intermediate spur gear 46 third spur gear
60 spindle motor
60a output shaft
61 High-speed drive helical gear
62 First reduction helical gear
63 1st small helical gear
64 Second reduction helical gear
65 second small helical gear
66 Third reduction helical gear
67 Helical gear for high speed rotation
71 drive gear shaft
72 flat belt

Claims (4)

In a gear drive device for a rotating shaft of a machine tool, a servomotor and a drive helical gear provided on the drive shaft of the servomotor, a first helical gear engaged with one of the helical gears, and A first intermediate shaft provided with a second helical gear coaxially with the first helical gear and reversely twisted with the first helical gear; and the second helical gear. A first intermediate gear that meshes with the helical gear; a second intermediate helical gear that meshes with the other helical gear; and a third helical gear that meshes with the second intermediate helical gear. And a second intermediate shaft provided with a fourth helical gear coaxially with the third helical gear and reversely twisted with the third helical gear. The intermediate helical gear 1 and the fourth helical gear are engaged with the driven helical gear provided on the rotary shaft at the same time. The by moving the first intermediate shaft in the axial direction, the drive is adjustable with the indexing gear drive consists of backlash adjusting device backlash between the driven helical gear with the helical gear, In addition, a spindle gear and a drive gear shaft that is separate from the spindle motor output shaft are hung with a flat belt between the output shaft and the drive gear shaft is provided on the opposite side of the flat belt. The high-speed drive is a helical gear, the high-speed drive is a first reduction helical gear meshing with the helical gear, and the first reduction helical gear is opposite in twist direction and is coaxially A first small helical gear, a second reduction helical gear meshing with the first small helical gear, and the second helical reduction gear. Twisting direction is reversed and installed on the coaxial lower side The second small helical gear, the third reduction helical gear meshing with the second small helical gear, and the third reduction helical gear are twisted. A gear mechanism having a high-speed rotation gear drive device comprising a multi-stage gear device having a reverse direction and a helical gear for high-speed rotation provided on the coaxial upper side, wherein the drive is a helical gear A clutch mechanism capable of connecting or disconnecting the drive shaft of the helical gear and the servo motor shaft is provided between the servo motor and the rotary shaft of the driven helical gear. A rotating shaft for a work table to be mounted, wherein the driven helical gear meshes with the high-speed rotating helical gear. In a gear drive device for a rotating shaft of a machine tool, a servomotor and a drive helical gear provided on the drive shaft of the servomotor, a first helical gear engaged with one of the helical gears, and A first intermediate shaft provided with a second helical gear coaxially with the first helical gear and reversely twisted with the first helical gear; and the second helical gear. A first intermeshing helical gear, a fifth helical gear meshing with the other helical gear, and the fifth helical gear coaxially with the fifth helical gear. A third intermediate shaft provided with a sixth helical gear having a reverse twist and a third intermediate helical gear meshing with the sixth helical gear, and the first intermediate gear. The intermediate helical gear and the third intermediate helical gear are simultaneously meshed with the helical gear provided on the rotary shaft. The by moving the first intermediate shaft in the axial direction, the drive is adjustable with the indexing gear drive consists of backlash adjusting device backlash between the driven helical gear with the helical gear, In addition, a spindle gear and a drive gear shaft that is separate from the spindle motor output shaft are hung with a flat belt between the output shaft and the drive gear shaft is provided on the opposite side of the flat belt. The high-speed drive is a helical gear, the high-speed drive is a first reduction helical gear meshing with the helical gear, and the first reduction helical gear is opposite in twist direction and is coaxially A first small helical gear, a second reduction helical gear meshing with the first small helical gear, and the second helical reduction gear. Twisting direction is reversed and installed on the coaxial lower side The second small helical gear, the third reduction helical gear meshing with the second small helical gear, and the third reduction helical gear are twisted. A gear mechanism having a high-speed rotation gear drive device comprising a multi-stage gear device having a reverse direction and a helical gear for high-speed rotation provided on the coaxial upper side, wherein the drive is a helical gear A clutch mechanism capable of connecting or disconnecting the drive shaft of the helical gear and the servo motor shaft is provided between the servo motor and the rotary shaft of the driven helical gear. A rotating shaft for a work table to be mounted, wherein the driven helical gear meshes with the high-speed rotating helical gear. In a gear drive for a rotating shaft of a machine tool, a servo spur, a drive spur gear provided on the drive shaft of the servo motor, a first spur gear meshing with one of the drive spur gears, and the first spur gear a first intermediate shaft second is given the helical gear is provided coaxially with the first intermediate helical gear meshing with the second of helical gear, the other of said drive Dohiraha vehicle A second intermediate shaft in which a second intermediate spur gear meshing, a third spur gear meshing with the second intermediate spur gear, and a fourth helical gear coaxially with the third spur gear Wherein the first intermediate helical gear and the fourth helical gear mesh with the driven helical gear provided on the rotating shaft at the same time, and By moving the intermediate shaft in the axial direction, backlash between the drive spur gear and the driven helical gear is reduced. Sei possible and the backlash adjustment index gear drive consists of device, as well as, the output shaft of the spindle motor and the spindle motor being flat belt hanging between the separate drive gear shaft and the output shaft, A high-speed driving helical gear provided on the drive gear shaft opposite to the flat belt, a high-speed driving helical gear meshing with a helical gear, the first reduction helical gear, The first helical gear is provided in the upper side of the same axis, and the second small reduction gear meshes with the first small helical gear. A helical gear, a second small helical gear provided in the lower side of the coaxial axis, and a second small helical gear, the torsion direction being opposite to those of the second reduction helical gear. A third reduction helical gear meshing with the gear; The gear mechanism is provided with a high-speed rotating gear drive device composed of a multi-stage gear device having a high-speed rotating helical gear provided on the upper side of the same axis and having a twist direction opposite to that of the high-speed helical gear. A clutch mechanism capable of connecting or disconnecting the drive shaft of the drive spur gear and the servo motor shaft is provided between the drive spur gear and the servo motor, and the driven helical gear is A rotating shaft is a rotating shaft for a work table on which a workpiece is placed, and the driven helical gear meshes with the helical gear for high-speed rotation. In a gear drive for a rotating shaft of a machine tool, a servo spur, a drive spur gear provided on the drive shaft of the servo motor, a first spur gear meshing with one of the drive spur gears, and the first spur gear a first intermediate shaft second is given the helical gear is provided coaxially with the first intermediate helical gear meshing with the second of helical gear, the other of said drive Dohiraha vehicle A fifth intermediate gear meshing with the fifth helical gear; a third intermediate shaft provided with a sixth helical gear coaxially with the fifth spur gear; and a third intermediate gear engaging with the sixth helical gear. A helical gear, wherein the first intermediate helical gear and the third intermediate helical gear are simultaneously meshed with the helical gear provided on the rotary shaft; By moving the first intermediate shaft in the axial direction, a backlash between the drive spur gear and the driven helical gear is achieved. Tsu Shi adjustable and the backlash adjustment index gear drive consists of device, as well as, separate drive gear shaft is flat belt hanging between the output shaft and the output shaft of the spindle motor and the spindle motor A high-speed driving helical gear provided on the drive gear shaft on the opposite side of the flat belt, and the high-speed driving helical gear meshing with the helical gear; The first reduction helical gear has a reverse twisting direction, and is engaged with the first small helical gear provided on the coaxial upper side and the first small helical gear. A helical gear for speed reduction, a second small helical gear provided on the lower side of the coaxial axis, and a second small helical gear having a reverse twist direction to that of the second reduction helical gear. A third reduction helical gear meshing with the helical gear and the front A gear provided with a high-speed rotating gear drive device comprising a multi-stage gear device having a helical gear for high-speed rotation provided on the upper side of the same axis and having a twisting direction opposite to that of the third reduction helical gear A clutch mechanism capable of connecting or disconnecting the drive shaft of the drive spur gear and the servo motor shaft is provided between the drive spur gear and the servo motor; The gear mechanism is characterized in that a rotation shaft of a gear is a rotation shaft for a work table on which a work is placed, and the driven helical gear meshes with the helical gear for high-speed rotation.