JP2808455B2 - Backlashless gear transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a gear transmission in which backlash is removed from among gear transmissions that transmit rotational driving force by gears.

[Conventional technology]

For example, various types of backlash removing mechanisms have been used in the meshing portion between a pinion and a gear, such as a reduction gear of a precision machine. 4 and 5 show a conventional example of the backlash removing mechanism. In both figures, reference numeral 102 denotes a main pinion, and screw holes 102a are drilled at two substantially axially symmetric locations, and fitted to the drive shaft 101. 103 is an adjustment pinion, and the above screw hole 102a
A slit-shaped bolt hole 103a is formed in two places corresponding to the above, and is rotatably fitted to the boss portion 102b of the main pinion 102. Then, both the main pinion 102 and the adjust pinion 103 are fastened by an adjust bolt 104 to form a split pinion 100.
The split pinion 100 meshes with the gear 106,
The rotation of 101 is transmitted to a driven shaft (not shown) via gear 106. To remove the backlash between the split pinion 100 and the gear 106, the adjusting bolt 104 is loosened, and as shown in FIG. 4, the adjusting pinion 103 is slightly rotated to increase the tooth thickness of the split pinion 100, Adjust the bite of.

When the meshing portion between the split pinion 100 and the gear 106 wears and the backlash exceeds an allowable value, the adjusting bolt 104 is loosened to increase the tooth thickness of the split pinion 100 again, and adjust the meshing condition of both. Further, as another backlash removing mechanism, there is a mechanism that urges a main pinion and an adjustment pinion of a split pinion with a spring to increase the tooth thickness, and the tooth surface always contacts the tooth surface of a gear.

[Problems to be solved by the invention]

The above conventional backlash removing device has the following problems to be solved.

That is, in the conventional backlash removing device, since the backlash removing and adjusting means are provided directly on the pinion and the gear, the backlash removing device is built in the power transmission device. There is a disadvantage that a large amount of work time is required for lash removal.

[Means for solving the problem]

The present invention provides, as a means for solving the above-mentioned problem, a gear transmission for transmitting rotational force from a drive shaft to a driven shaft by a gear, wherein the drive shaft and the driven shaft have different twist angles and the same pitch circle diameter. A bearing in which two sets of torsional gears that directly mesh with the gears are arranged in the axial direction and the drive shaft or the driven shaft is supported so as to be movable in the axial direction;
It is an object of the present invention to provide a backlash-less gear transmission, characterized in that one of the drive shaft and the driven shaft is provided with a movement adjusting device for moving and adjusting the coaxial movement in the axial direction.

[Action]

The present invention has the following effects because it is configured as described above.

That is, when the drive shaft or the driven shaft is to be moved in the axial direction by the movement adjusting device, first, the meshing portions of the two torsion gears having a small torsion angle come into contact with each other, and the torsion gear of the drive shaft or the driven shaft to be moved. Is guided by the torsional gear of the fixed driven shaft or the drive shaft, and moves while rotating like a screw according to the torsion angle.

Due to the movement of the drive shaft or the driven shaft, the meshing portions of the two torsion gears having large torsion angles come into contact with each other, and the movement in the axial direction stops.

At this time, the mesh surface of the meshing portion of the torsion gear having a small torsion angle and the tooth surface of the meshing portion of the torsion gear having a large torsion angle are in contact with each other, and the backlash is removed. Therefore, according to the means of the present invention, one of the two sets of torsion gears is only axially moved and adjusted by a movement adjusting device on one of the drive shaft or the driven shaft to which one side of the two sets of torsion gears are mounted, and thus the two sets of gears are provided. Backlash can be removed at the same time.

〔Example〕

 A first embodiment of the present invention will be described with reference to FIG.

FIG. 1 is a vertical cross-sectional view of a power transmission device according to the present invention, which is resistant to occurrence of backlash, such as an arm pivot of a robot or a speed reducer of an intermittent feeding device of a precision press.

In the figure, reference numeral 1 denotes a drive shaft, on which a helical pinion 2 having a large torsion angle θ _{1 and} a helical guide pinion 3 having a small torsion angle θ ₂ are fitted, and supported on a casing 10 via a roller bearing 4. Inner ring 4a of roller bearing 4
However, 4b slides in the axial direction, and the drive shaft 1 is movable in the axial direction. Reference numeral 5 denotes a driven shaft, which is arranged in parallel (different center) with the drive shaft 1 and meshes with the helical pinion 2;
A helical guide gear 7 meshing with the helical guide pinion 3 is fitted in parallel with the helical pinion 2 and the helical gear 6 in the axial direction, respectively, and is supported by a casing 10 via a roller bearing 8. As is clear from FIG. 1, the helical gear 6 and the helical guide gear 7 have the same pitch circle diameter, and the helical pinion 2 and the helical guide pinion 3 have the same pitch circle diameter. Numeral 11 denotes a nut fixed to the outer surface of the casing 10, and numeral 13 denotes an adjuster screwed to the nut 11.
The working side (left side in the figure) is supported by the adjuster 13 and the nut 11 via the thrust bearing 9. Nut 11
The lever 12 is pivotally attached to the groove engraved on the outer peripheral end of
A number of stoppers 13a are provided around the outer circumference of the adjuster 13,
The levers 12 are protruded at intervals at which the levers 12 can be inserted. Reference numeral 14 denotes a lid, which is a rotating hole into which a handle (not shown) is inserted to rotate.
14a is formed in a cross shape and is fixed to the end face of the adjuster 13. In removing the backlash between the helical pinion 2 and the helical gear 6, the drive shaft 1 is brought into an idle state, and the lever 12 is rotated as shown by a two-dot chain line to be pulled out from between the stoppers 13a. When the is rotated, the adjuster 13 moves rightward in the figure by screwing with the nut 11, and moves the drive shaft 1 to the drive side (rightward in the figure) via the thrust bearing 9. Now, temporarily,
If the twist angle theta ₁ of the helical pinion 2 and the twist angle theta ₂ of the helical guide pinion 3 and are the same,
Guided by the fixed helical gear 6 and the helical guide gear 7, the meshing portions slide, and the drive shaft 1, the helical pinion 2, and the helical guide pinion 3 are screw-like in accordance with the twist angles θ ₁ and θ _2. It continuously moves to the drive side while rotating. However, greater than the twist angle theta ₁ of the helical pinion 2 twist angle theta ₂ of the helical guide pinion 3, and helical pinion 2 and the helical guide pinion 3, as well as a helical gear 6 and the helical guide gear 7, the respective pitch circle Therefore, when the meshing portion between the helical pinion 2 and the helical gear 6 comes into immediate contact and the gap becomes zero, the rotation and the movement to the driving side are stopped, and the helical pinion 2 and the helical gear 6 are stopped.
Backlash with is eliminated. At this time, since the meshing portion between the helical guide pinion 3 and the helical guide gear 7 is in contact and sliding, the gap is zero, and the backlash is eliminated. Then the lever
The adjuster 13 is fixed by rotating the pivot 12 and inserted between the stoppers 13a as shown in the figure, and the engaging portion is fixed.

FIG. 2 is a longitudinal sectional view showing a main part of a power transmission device according to a second embodiment of the present invention. Parts other than those shown in the drawing and members denoted by the same reference numerals as those in the first embodiment are the same as those in FIG. This is the same as in the first embodiment.

In FIG. 2, reference numeral 21 denotes a cylinder fixed to the outer surface of the housing 10, and 22 denotes a lid fixed to an end face of the cylinder 21, and a spring is provided between the lid 22 and the thrust bearing 9.
23 are interposed. In the second embodiment, the drive shaft 1 is constantly pressed rightward in the figure by a spring 23, and backlash is removed by the same operation as in the first embodiment.

FIG. 3 is a longitudinal sectional view of a drum shear according to a third embodiment of the present invention, in which the backlash removing mechanism of the first embodiment is used for a drum shear.

In FIG. 3, reference numeral 51 denotes a drive shaft, on which a lower drum 51a having a lower knife 51b is fitted, and further, a torsion angle θ _{11 is provided.}
Helical mecha tie gear 52 with large torsion angle θ ₁₂
And a lower helical distribution gear 53 having a small diameter, which is fitted to a bearing stand 60 via a roller bearing 54. As with the roller bearings 4 of the first and second embodiments, the roller bearing 54 is slidable in the axial direction with respect to the inner rings 54a and 54b.

55 is a driven shaft, and an upper drum 55a having an upper knife 55b
Are fitted and further mesh with the lower helical mechanical tie gear 52, and the lower helical distribution gear 53
And the upper helical distribution gear 57 that meshes with
It is supported on a bearing stand 60 via a roller bearing 58.

61 is a nut fixed to the outer surface of the bearing stand 60, 63 is an adjuster screwed to the nut 61, and the working side of the drive shaft 51 is supported by the adjuster 63 and the nut 61 via a thrust bearing 59. I have. A lever 62 is pivotally mounted on the nut 61, and a number of stoppers 63a are provided on the outer periphery of the adjuster 63.
However, they are protruded at intervals at which the lever 62 can be inserted.

Reference numeral 64 denotes a lid, which is formed with a cross-shaped hole 64a for inserting a handle (not shown) in a cross shape, and is fixed to the end face of the adjuster 63.

Lower helical tie gear 52 and upper helical tie gear
In removing backlash of the meshing portion between the lower helical distribution gear 53 and the upper helical distribution gear 57, first, the driven shaft 55 and the upper drum 55a are fixed at the position of the lower dead center of the upper knife 55b, and the lower knife 51b From the lower drum 51a.

Next, the lever 62 is removed from the stopper 63a, the lid 64 and the adjuster 63 are rotated to move the inside of the nut 61 to the drive side (right side in the drawing), and the drive shaft 51 is moved to the drive side via the thrust bearing 59. Then, the backlash is removed by the same operation as in the first embodiment.

Next, the lower knife 51b is mounted on the lower drum 51a, and the gap between the lower knife 51b and the upper knife 55b is adjusted to a predetermined size by a shim or the like.

In each of the first, second, and third embodiments, an axial movement device such as a screw rotation and a spring is provided on the working side of the drive shaft. It may be provided on the driving side of the shaft, in the third embodiment on the driving side or the working side of the driven shaft.

As described above, according to the first, second, and third embodiments, the torsional angles of the two sets of torsional gears having different torsional angles provided on the drive shaft and the driven shaft are different. Is moved, the torsional angles of each set of gears are different, so, for example, while one set of teeth and the other set of teeth form tapered grooves with different phases, Similar to the effect when a wedge with a different inclination angle enters, the wedge first contacts one side of the groove, and as the approach proceeds, the opposite side abuts on the opposite side of the groove, and the phase stops in the same manner as the approach stops. A pair of different surfaces enter and stop on both sides of the groove, i.e., each tooth having a different twist angle. Therefore, a gear transmission in which the backlash from the left and right, that is, the backlash is completely removed when viewed in the approach direction is obtained.

Note that, depending on the deviation of the pitch of both teeth on the pitch circle of the gear when viewed in the entry direction (axial direction), the pair of teeth that enter firstly contacts the other tooth regardless of the magnitude of the twist angle. Although there may be no case, the effect described above is obtained in the result.

Further, as is clear from the description of the above embodiments and FIGS. 1 and 3, since the movement adjusting device is provided at the end of the drive shaft (or the end of the driven shaft), its assembly, adjustment, maintenance and inspection are easy. It also has the advantage that it can be performed.

〔The invention's effect〕

The present invention has the following effects because it is configured as described above.

That is, by providing two sets of torsional gears having different torsion angles on the drive shaft and the driven shaft, only one of the drive shaft and the driven shaft is moved in the axial direction, and the intermediate shaft and the intermediate gear are used. With a simple and low-cost structure that does not require any, the backlash of the two sets of torsional gears connecting both shafts can be easily eliminated.

Also, the provision of the axial movement adjusting device outside the gear transmission facilitates its assembly, adjustment, maintenance and inspection work, and backlash removal operation.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a gear transmission according to a first embodiment of the present invention, FIG. 2 is a longitudinal sectional view showing a main part of a gear transmission according to a second embodiment of the present invention, and FIG. 4 is a longitudinal sectional view of a drum shear provided with a gear transmission according to a third embodiment of the present invention, FIG.
FIG. 5 is a front view of a split pinion and a gear as an example of a conventional backlash removing mechanism, and FIG.
It is V arrow sectional drawing. DESCRIPTION OF SYMBOLS 1 ... Drive shaft, 2 ... Helical pinion, 3 ... Helical guide pinion, 4 ... Roller bearing, 5 ... Driven shaft, 6 ... Helical gear, 7 ... Helical guide gear, 9 ... Thrust bearing, 10 ... Casing, 11 ... Nut, 13 ... Adjuster, 21 ... Cylinder, 22 ... Lid, 23 ... Spring, 51 ... Drive shaft, 52 ... Lower helical mechanical tie gear, 53 ... Lower helical distribution Gears, 54: Roller bearings, 55: Driven shaft, 56: Upper helical mecha tie gear, 57: Upper helical distribution gear, 59: Thrust bearing, 60: Bearing stand, 61: Nut, 63 ... ... _{adjuster, θ 1 · θ 2 · θ} 11 · θ 12 ...... twist angle.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16H 57/12 F16H 1/26 F16H 55/18

Claims (1)

(57) [Claims] 1. A gear transmission for transmitting a rotational force from a drive shaft to a driven shaft disposed in parallel with the drive shaft by a gear, wherein the drive shaft and the driven shaft have different twist angles and a pitch circle diameter. The same, two sets of torsional gears that directly mesh with the mating gear are arranged side by side in the axial direction, and a bearing that supports the drive shaft or the driven shaft so as to be movable in the axial direction;
A backlash-less gear transmission, characterized in that one of the drive shaft and the driven shaft is provided with a movement adjusting device that moves and adjusts coaxially in the axial direction.