JPH09152015A - Scissors gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance reliability by reducing the wear of locking pins exerted with the torque of a torsion ring and that of the torsion ring. SOLUTION: This scissors gear has a main gear 11 with a first locking pin 11d with which one end of a torsion ring 13 is locked, and has a subsidiary gear 12 with a second locking pin 12b locked with the outer end of the torsion ring. The subsidiary gear 12 is provided on the same axis as the rotation axis of the main gear 11 and on one side of the main gear 11 via the torsion ring 13 in such a way to be rotatable relative to the main gear 11. The torsion ring 13 is designed to produce torque with which the subsidiary gear 12 is circumferentially twisted with respect to the main gear 11 by the first and second locking pins 11d, 12b. Tubular carburized bushes 14, 14 are fitted around the first and second locking pins 11d, 12b, and the ends of the torsion ring are locked to the first and second lock pins 11d, 12b via the bushes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scissors gear which prevents gear rattling noise caused by backlash which is a clearance between tooth surfaces between a mating mating gear and a main gear.

[0002]

2. Description of the Related Art Conventionally, a sub gear in a scissors gear is provided on the same axis as a rotation axis of a main gear meshing with a counterpart gear, and is provided on one side surface of the main gear so as to be rotatable relative to the main gear. Mesh with
In addition, it is known that a torsion ring is housed between the sub gear and the main gear. The main gear is provided with a first locking pin that locks one end of the torsion ring, and the sub gear is provided with a second locking pin that locks the other end of the torsion ring. One end of the torsion ring is locked to the first locking pin and the other end is locked to the second locking pin, and a torsional force for twisting the sub gear in the circumferential direction with respect to the main gear is generated. Therefore, the elastic force of the torsion ring causes the sub gear to sandwich the teeth of the mating gear together with the teeth of the main gear to eliminate backlash and prevent rattling noise.

[0003]

However, in the conventional scissors gear, the rattling of the torsion ring while the scissors gear is driven causes the torsion ring and the first and second locking pins to be worn and to receive the torsion force of the torsion ring. There is a problem that the areas of the first and second locking pins are reduced due to the wear. This reduction of the area has a drawback that the wear of the locking portion of the torsion ring and the respective locking pins are further accelerated to shorten the life. In order to eliminate this point, it is conceivable to increase the diameter of the first and second locking pins to increase the contact area. However, the main gear and the sub gear are usually carburized in order to improve wear resistance, and the first locking pin and the second locking pin that lock the torsion ring are press-fitted after the main gear and the sub gear are carburized. ing. For this reason, there is a problem that the hardness of the press-fitting operation of the first and second locking pins into the carburized main gear and sub gear is difficult. An object of the present invention is to provide a scissors gear that reduces the wear of each locking pin and the torsion ring that receive the torsional force of the torsion ring and improves the reliability thereof.

[0004]

A configuration of the present invention for achieving the above object will be described with reference to FIG. 1 corresponding to an embodiment. The invention according to claim 1 is, as shown in FIG. 1, a first locking pin 11d with which one end of the torsion ring 13 is locked.
And a sub gear 12 having a second locking pin 12b that locks to the other end of the torsion ring 13.
The sub gear 12 is provided on the same axis as the rotation axis of the main gear 11, and is provided on one side surface of the main gear 11 via a torsion ring 13 so as to be rotatable relative to the main gear 11. Reference numeral 13 denotes the main gear 1 by means of the first and second locking pins 11d and 12b.
It is an improvement of the scissors gear configured to generate a twisting force for twisting the sub gear 12 in the circumferential direction with respect to 1. The characteristic configuration is that the first and second locking pins 11d and 12 are
The carburized tubular bushes 14 and 14 are fitted in b, and one end and the other end of the torsion ring 13 are inserted into the first and second locking pins 11 via the bushes 14 and 14, respectively.
d and 12b respectively.

The carburizing treatment is generally called carbon stripping,
It is a treatment method carried out to increase the carbon content of the steel for improving the wear resistance. The treatment method is heating in a suitable medium. That is, low carbon steel, low nickel steel, or low nickel-chromium steel is placed in the carburizing agent and heated to 850 to 900 ° C for 8 hours.
After heating for 10 hours, the surface of the rope is carburized to a depth of about 2 mm. The carburizing agent is a solid carburizing agent such as wood and coke, a gas carburizing agent such as coal gas containing carbon monoxide and hydrocarbons or light gas, and a liquid generally called a bluing method such as potassium cyanide and soda blue. Three types of carburizing agents are known, and any carburizing agent may be used. After the carburizing treatment, it is preferable to perform a heat treatment to harden the carburized portion. In this scissors gear, the bush 14 is fitted to increase the outer diameters of the first and second locking pins 11d and 12b, and the bushes are carburized to improve wear resistance. First and second locking pin 11
By increasing the outer diameters of d and 12b, the area where one end and the other end of the torsion ring contact the bush 14 is enlarged. By increasing this area, the load applied per unit area is reduced, and the wear of the torsion ring and the locking pin is reduced.

According to the second aspect of the invention, as shown in FIG. 6, the main gear 21 to which one end of the torsion ring 23 is locked, and one side surface of the main gear 21 provided on the same axis as the rotation axis of the main gear 21. The torsion gear 23 has a sub gear 22 that is provided so as to be rotatable relative to the main gear 21 and locked to the other end of the torsion ring 23. The torsion ring 23 twists the sub gear 22 in the circumferential direction with respect to the main gear 21. It is an improvement of a scissors gear configured to generate a twisting force. The characteristic configuration is that the one end of the torsion ring 23 has a carburized first locking pin 23.
a is projected toward the main gear 21, a second locking pin 23b carburized at the other end of the torsion ring 23 is projected toward the sub gear 22, and the first locking pin 23a can be inserted into the main gear 21. A second hole 22a into which the second locking pin 23b can be inserted is provided in the sub gear 22, and the first locking pin 23a is inserted into the first hole 2a.
One end and the other end of the torsion ring 23 are locked to the main gear 21 and the sub gear 22, respectively, by inserting the second locking pin 23b into the first hole 1a and inserting the second locking pin 23b into the second hole 22a. In this scissors gear, the first and second locking pins 23a and 23b are inserted into the first and second holes 21a and 22a, and the sub gear 22 is fitted into the main gear 21. The first and second locking pins 23a, 23b have holes 21a, 22a.
The one end and the other end of the torsion ring 23 are engaged with the main gear 21 and the sub gear 22, respectively. Since the first and second locking pins 23a, 23b are carburized, the first and second locking pins 23a, 23b are
The wear of each is reduced.

[0007]

Next, a first embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 to 5, the scissors gear 10 includes a main gear 11, a sub gear 12 having the same number of teeth and the same tooth profile as the main gear 11,
And a torsion ring 13. The main gear 11 is provided with a fitting hole 11a at the center for fitting into a shaft (not shown),
Around the fitting hole 11a, there is a step portion 11b into which the sub gear 12 is fitted. Further, the mounting portion 11c on which the torsion ring 13 is mounted is attached to the side surface of the main gear 11 on the side of the step
(FIG. 1) is provided, and the mounting portion 11c is fixed by press-fitting a cylindrical first locking pin 11d with which one end of the torsion ring 13 is locked. The mounting portion to which the torsion ring is mounted may be provided in the sub gear instead of the main gear.

The sub gear 12 is provided with a through hole 12a which is fitted into the stepped portion 11b of the main gear 11, and a second cylindrical column with which the other end of the torsion ring 13 is engaged with the surface of the sub gear 12 facing the main gear 11. The locking pin 12b is fixed by being press-fitted. With the through hole 12a of the sub gear 12 fitted in the step portion 11b of the main gear 11, the outer shape of the sub gear 12 matches the outer shape of the main gear 11, so that the sub gear 12 can rotate relative to the main gear 11. Has become.

The torsion ring 13 is mounted on the mounting portion 11c of the main gear 11 so as to be sandwiched between the main gear 11 and the sub gear 12. As shown in FIG. 4, the torsion ring 13 is formed by cutting out a part of the ring,
Semi-circular first and second locking portions 1 are provided on both end surfaces of the cutout portion.
3a and 13b are provided, respectively. The first and second locking portions 13a and 13b are the first and second locking pins 11d and 12 respectively.
Lock to b respectively. When the torsion ring 13 is locked and the sub gear 12 is twisted with respect to the main gear 11 in the direction shown by the solid line arrow in FIG. 1, the locking pin 12b opens the torsion ring 13 as shown in FIG. . In this state, when meshed with a mating gear (not shown), the torsion force of the torsion ring 13 urges the sub gear 12 in the circumferential direction with respect to the main gear 11, and the sub gear 12
The teeth of the other gear sandwich the teeth of the mating gear together with the teeth of the main gear 11. As a result, the scissors gear 10 can eliminate backlash and prevent rattling noise.
Main gear 11, sub gear 12, and torsion ring 1
5, the rings 3 are assembled by fitting the rings 15 into the recesses 11h provided in the step portion 11b via the disc springs 16 as shown in FIG.

The characteristic structure of this embodiment is shown in FIGS.
As shown in FIG. 1, the carburized tubular bushes 14, 14 are fitted into the first and second locking pins 11d, 12b, respectively, and the first and second engaging members provided at one end and the other end of the torsion ring 13 are engaged. The stoppers 13a and 13b are connected to the first and second locking pins 11d via the bushes 14 and 14,
12b are each locked. Bush 14
Has an inner diameter that can be fitted into the first and second locking pins 11d and 12b, and is machined to have an outer diameter that allows surface contact with the first and second locking portions 13a and 13b. Further, the height of the bush 14 is processed to have a dimension slightly lower than the height of the mounting portion 11c, and carburizing is performed.

The operation of the scissors gear 10 thus constructed will be described. With the sub gear 12 fitted in the main gear 11, the first and second locking pins 11d and 12b are in surface contact with the first and second locking portions 13a and 13b of the torsion ring via the bushes 14 and 14, respectively. First and second locking pins 11d, 1 into which the bush 14 is fitted
2b has a large outer diameter, and the first and second locking portions 13
The area in contact with a and 13b is enlarged. By increasing this area, the load applied per unit area is reduced, and the wear of the torsion ring and the locking pin is reduced.

6 to 8 show a second embodiment of the present invention. Among the reference numerals in the drawings, the same reference numerals as those in the first embodiment indicate the same parts. As shown in FIG. 6, the scissors gear 20 includes a main gear 21 and a sub gear which is provided on the same axis as the rotation axis of the main gear 21 and is rotatable on one side surface of the main gear 21 with respect to the main gear 21. 22 and. Both the main gear 21 and the sub gear 22 are carburized to improve their wear resistance. One end of the torsion ring 23 is locked to the main gear 21, and the sub gear 22 is locked to the other end of the torsion ring 23. When the sub gear 22 is twisted with respect to the main gear 21 in the direction shown by the solid line arrow in FIG. 6, the torsion ring 23 opens and the torsion ring 23
Is configured to generate a twisting force for twisting the sub gear 22 in the circumferential direction with respect to the main gear 21.

The characteristic configuration of this embodiment is shown in FIGS.
As shown in FIG. 5, a carburized first locking pin 23 a is projectingly provided at one end of the torsion ring 23 toward the main gear 21, and a carburized second locking pin 23 b is provided at the other end of the torsion ring 23 as a sub gear. It is located where it is projected toward 22. The first locking pin 2 is attached to the main gear 21.
A first hole 21a into which 3a can be inserted is provided, and the sub gear 2
2 is provided with a second hole 22a into which the second locking pin 23b can be inserted. By inserting the first locking pin 23a into the first hole 21a and inserting the second locking pin 23b into the second hole 22a, one end and the other end of the torsion ring 23 are inserted into the main gear 2.
1 and the sub gear 22 respectively.

In the scissors gear 20 having such a structure, the first and second locking pins 23a and 23b have the first and second holes 2 when the sub gear 22 is fitted in the main gear 21.
It is inserted into 1a, 22a and abuts on the peripheral edges of the holes 21a, 22a. Since the first and second locking pins 23a and 23b, the main gear 21 and the sub gear 22 are carburized, the peripheral edges of the first and second locking pins 23a and 23b and the first and second holes 21a and 22a are Scissors gear 20
The wear due to the rattling of the torsion ring 23 during the driving of is reduced.

[0015]

As described above, according to the present invention, the carburized tubular bushes are fitted into the first and second locking pins, respectively, and one end and the other end of the torsion ring are inserted through the bushes. Since the first and second locking pins are configured to be respectively locked, the outer diameters of the first and second locking pins can be increased, and the area of surface contact with the bush can be increased. As a result, the load applied per unit area of the bush is reduced, and the wear of the torsion ring and the locking pin is reduced.

Further, carburized first and second locking pins are provided at one end and the other end of the torsion ring so that the first and second locking pins can be inserted into the main gear and the sub gear. If two holes are provided and the first and second locking pins are inserted into the first and second holes so that one end and the other end of the torsion ring are respectively locked to the main gear and the sub gear, carburizing Because of being
The respective wear of the first and second locking pins and the peripheral edges of the respective holes is reduced. As a result, it is possible to reduce the wear of the first and second locking pins and improve the reliability of the scissors gear.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a scissors gear according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the scissors gear taken along the line AA of FIG.

3 is an enlarged view of part B in FIG.

FIG. 4 is a front view in which a torsion ring is attached to a main gear of the scissors gear.

FIG. 5 is a sectional view taken along line CC of FIG. 4;

FIG. 6 is a view corresponding to FIG. 1 showing a scissors gear according to a second embodiment of the present invention.

FIG. 7 is a view corresponding to FIG. 2 showing the scissors gear.

FIG. 8 is a view corresponding to FIG. 3 showing the scissors gear.

[Explanation of symbols]

 10,20 Scissors gear 11,21 Main gear 11d, 23a First locking pin 12,22 Sub gear 12b, 23b Second locking pin 13,23 Torsion ring 14 Bush 21a First hole 22a Second hole

Claims (2)

[Claims] 1. A main gear (11) having a first locking pin (11d) with which one end of the torsion ring (13) is locked, and a second locking pin with which the other end of the torsion ring (13) is locked. (12
b) having a sub gear (12), the sub gear (12) is provided on the same axis as the rotation axis of the main gear (11), and the main gear (11) is provided on one side surface of the main gear (11).
The torsion ring (13) is rotatable relative to
And the torsion ring (13) is connected to the main gear (1) by the first and second locking pins (11d, 12b).
In a scissors gear configured to generate a torsional force that twists the sub gear (12) in the circumferential direction with respect to 1), the first and second locking pins (11d, 12b) having a tubular shape carburized Bushings (14, 14) are fitted respectively, and one end and the other end of the torsion ring (13) are provided with the first and second locking pins (11d, 12b) via the bushes (14, 14).
Scissors gear characterized by being locked to each. 2. A main gear (21) with which one end of a torsion ring (23) is locked, and a main gear (21) provided on the same axis as the rotation axis of the main gear (21) on one side surface of the main gear (21). 21) and a sub gear (22) provided so as to be rotatable relative to the other end of the torsion ring (23), the torsion ring (23) being the main gear (21). A scissors gear configured to generate a torsional force that twists the sub gear (22) in the circumferential direction, the first carburized first end of the torsion ring (23)
The locking pin (23a) is projected toward the main gear (21), and the other end of the torsion ring (23) is carburized second.
The locking pin (23b) is provided so as to project toward the sub gear (22), and the main gear (21) is provided with a first hole (21a) into which the first locking pin (23a) can be inserted. The (22) is provided with a second hole (22a) into which the second locking pin (23b) can be inserted, and the first locking pin (23a) is inserted into the first hole (21a) and By inserting the locking pin (23b) into the second hole (22a), one end and the other end of the torsion ring (23) are locked to the main gear (21) and the sub gear (22), respectively. And scissors gear.