JPS61105367A - Back gap removal device - Google Patents

Abstract

PURPOSE:To aim at compactification in a backlash eliminator, by coupling and locking either of a main shaft or a subshaft to a gear in a state of being given the torsional deformation required. CONSTITUTION:A gear 16 is coupled and locked to a subshaft 25 in a state of being added to the torsional deformation required, in advance. With restorating force of the torsional deformation, a driving gear 14 and a first subgear 16 as well as driven gear 17 and a second subgear 22 all come into contact with one side tooth surface all the time. Likewise, through the driving gear 14 and the driven gear 17, the restoring force is also transmitted to a first main gear 15 and a second main gear 21 whereby these gears also come into contact with one side tooth surface.With this constitution, two sets of backlash eliminators are required in the past but now it gets off with one set, thus compactification come to fruition.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a back gap removing device for removing back gaps in gear mechanisms of machine tools, automatic machines, etc.

Structure of the conventional example and its problems A conventional back gap removing device has a specific structure as shown in FIGS.

A first main gear 2 and a first sub-gear 3 mesh with the drive gear 1, and a second main gear 5 and a second sub-gear 6 mesh with the driven gear 4. The first main gear 2 and the second main gear 5 are connected by a main shaft 7 and transmit driving force, and are connected to a housing 9 by a bearing 8.
is rotatably supported. Second secondary gear 6 and secondary shaft 10
It is fixed coaxially with the housing 9 and is rotatably supported by the housing 9 through a bearing 11. The first auxiliary gear 3 and the auxiliary shaft 1o are rotatably fitted coaxially, and are coupled by a spring 13 mounted between the flange portion 12 of the auxiliary shaft 1o. By applying initial tension to the spring 13, a relative rotational force is generated between the first auxiliary gear 3 and the auxiliary shaft 10, and each gear is pressed against one tooth surface due to this rotational force. For this reason, when the driving gear 1 is fixed, each gear is always in contact with one tooth surface, so the back clearance is virtually eliminated, and the driven gear 4 is positioned in the only position with no play. .

However, the above configuration has the disadvantage that the back gap removing device as a whole becomes large because there are two gear trains of the main shaft 7 and the sub shaft 10 corresponding to the intermediate shaft.

OBJECTS OF THE INVENTION In view of the above drawbacks, the present invention provides a back gap removing device that can remove back gaps and has a compact structure.

Composition of the Invention The present invention provides a driving gear, a driven gear, a second main gear connected to a first main gear meshing with the driving gear by a main shaft, a second main gear meshing with the driven gear, and a first auxiliary gear meshing with the driving gear. and a second auxiliary gear that meshes with the driven gear, which is connected by a auxiliary shaft, and the first main teeth T1, i2 main gears, the first auxiliary gear, the second auxiliary gear, the main shaft, and the auxiliary shaft are provided concentrically. By fixing one of the main shaft or the sub-shaft to the gear while being torsionally deformed, it has the unique effect of being compact and eliminating back gaps.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows the main structure of the back gap removing device in the first embodiment of the present invention. In FIG. 3, 14 is a drive square gear, and 15 is a first main gear that meshes with the drive gear 14. 16 is a first auxiliary gear that meshes with the drive gear 14;
It has the same number of teeth as the main gear 16 and is provided concentrically. Reference numeral 17 denotes a driven gear, which is fixed to the output shaft 18 and rotatably supported by the housing 2o via the output shaft 1BFi bearing 19.

21 is a second main gear, which meshes with the driven gear 17. 2
2 is a second auxiliary gear which meshes with the driven gear 17, has the same number of teeth as the second main gear, and is supported concentrically.

23 is a main shaft, the first main gear 15 and the second main gear 21
It is a hollow shaft concentrically connected to the housing 2o, and is rotatably supported by a bearing 24 with respect to the housing 2o. In this embodiment, the main shaft 23 is formed integrally with the second main gear 21, and the main shaft 23 is integrally formed with the second main gear 21.
It is contracted and fastened to the main gear 15. Reference numeral 25 denotes a subshaft, which concentrically connects the first sub-gear 16 and the second sub-gear 22. The countershaft 26 is rotatably and concentrically supported on the main shaft 23 by bearings 26,27. Subshaft 25 and the first
The secondary gear 16 and the secondary gear 16 are fixedly connected to each other with a required torsional deformation applied to the secondary shaft 25. At this time, the other shafts and gears are already fixed.

The operation of the back gap removing device configured as above will be explained below. Since the gears are fixed to the secondary shaft 25 with the required torsional deformation applied in advance, the driving gear 14 and the first secondary gear 16, and the driven gear 17 and the second secondary gear 22 are always in one direction due to the restoring force of the torsional deformation. The tooth surface will be in contact with the tooth surface. Similarly, the restoring force is also transmitted to the first main gear 16 and the second main gear 21 through the drive gear 14 and the driven gear 17, and these gears also contact each other at one tooth surface.

Due to these actions, there is virtually no back gap between the driving gear 14 and the driven gear 17 when the gear is stopped, resulting in positioning without backlash. Furthermore, when there is a sudden change in load torque such as during acceleration or deceleration, the impact is absorbed by the applied screw deformation. Furthermore, in this embodiment, the main shaft and the sub-shaft are coaxial, and one is housed in the hollow part of the other, so the overall size is small. In addition, in a method such as this example in which a rotational force is always applied to the gear in one direction and the back clearance is removed, the clearance between the tooth surfaces in the assembled state, the so-called back clearance amount, is the required initial value. It is closely related to the amount of torsional deformation, and it is necessary to strictly control the amount of back clearance during assembly. For this reason, it is necessary to selectively assemble gears or combine a back gap adjustment mechanism.

However, by making them coaxial as in this embodiment, only one set of back gap adjustment mechanisms is required compared to two sets in the conventional example, and there are also effects such as improved assembly efficiency and cost reduction.

In addition, since torsional deformation is applied to the sub-shaft with a small outer diameter and a long shaft length, the amount of torsional rotation relative to the required setting torque becomes large, and at the same time, the allowable range of the setting value is also wide, which reduces manufacturing variations. It becomes less. Since the main shaft and sub-shaft are still fitted coaxially, the screw loads are different, but the bending moment is borne by the outer main shaft 23 which has high bending rigidity, so as in the conventional example, each shaft is There is no need to design it to withstand bending moment, which allows for a more rational design.

The second embodiment of the present invention will be described below with reference to FIG. 4(a).

This will be explained with reference to (b). Figure 4 (-), (
b) is an enlarged view of a main part of a back gap removing device according to a second embodiment of the present invention, which is different from the first embodiment. This example is the first
What differs from the embodiment shown in FIG. 16 as secondary axis 2
However, in this example, a mechanism was provided to adjust the amount of twist after assembly. 25a is subshaft 2
16a is a protrusion provided on the first auxiliary gear 16.

The protrusion 16a is threaded and an adjustment bolt 28 is inserted therein. The protrusions 25a and 16a fit together, and the adjustment bolt 2
8 can change the rotational angular position between the protrusions 25a and 16a, and this operation can provide the required amount of torsional deformation.

As described above, by providing the fixed position adjustment mechanism between the shaft and the gear and in the rotation angle direction, there is an advantage that assembly and adjustment are facilitated.

In the present embodiment, the subshaft is housed in the hollow part of the main shaft, but the reverse may be used, and the subshaft is used as the shaft that provides the required torsional deformation, but it may be the main shaft or both. Although the shaft and gears are still connected by shrinkage fastening, this method is not limited to this method. Any convenient connection method such as keying, splining, bolting, etc. may be used. In short, it is sufficient if the shaft can be fixed on the gear while giving the required amount of torsional deformation. Further, although a bearing is used between the main shaft and the sub-shaft, a simple fit may be used, as long as a certain degree of relative rotation is possible. Further, although a straight tooth spur gear is used as the gear, it goes without saying that a helical tooth spur gear can also be used. In addition to spur gears, bevel gears can also be used. Further, the rotation angle direction fixed position adjusting device shown in the second embodiment is not particularly limited to this method, and it is sufficient that the position between the shaft and the gear in the rotation angle direction can be adjusted and fixed.

Effects of the Invention As described above, the present invention provides a driving gear, a driven gear, a second main gear connected to the first main gear meshing with the driving gear by a main shaft, and a second main gear meshing with the driven gear, and a second main gear meshing with the driving gear. a second auxiliary gear connected to a first auxiliary gear by a countershaft and meshing with a driven gear;
The secondary gear, main shaft, and secondary shaft are provided concentrically, and by fixing one of the main shaft or secondary shaft to the gear with the required torsional deformation, a compact structure can be achieved, and the back gap can be reduced. can be removed, and the effect is similar to that of a dog.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional front view showing an outline of a conventional back gap removing device, FIG. 2 is a side view of the main part of FIG. 1, and FIG. 3 is a back gap removing device according to the first embodiment of the present invention. 4(d) and (b) are a front view and a side view of a main part of a back gap removing device according to a second embodiment of the present invention. 14... Drive gear, 16... First main gear, 16... First auxiliary gear, 17... Driven gear, 21...・Second main gear, 22...
・Second secondary gear, 23...Main shaft, 26...
・Secondary axis. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4rg (a) Do8 16a-

Claims (2)

[Claims] (1) a drive gear, a driven gear, a first main gear that meshes with the drive gear, and a first auxiliary gear that is arranged concentrically with the first main gear and meshes with the drive gear that has the same number of teeth; a second main gear that meshes with the driven gear; a second auxiliary gear that is arranged concentrically with the second main gear and meshes with the driven gear that has the same number of teeth;
A main shaft that fixedly connects the first main gear and the second main gear and rotatably supports the gear; and a subshaft that firmly connects the first sub gear and the second sub gear and rotatably supports the gear. , at least one of the main shaft and the sub-shaft is a hollow shaft, and the other shaft is provided concentrically in the hollow part, and each Back gap removal device with fixed gears and each shaft. (2) The back gap removing device according to claim 1, wherein the main shaft or the sub-shaft is provided with a mechanism for adjusting the fixing position in the rotation angle direction of the gear coupled to the main shaft.