JP2010247987A - Driving device of rack & pinion gear applicable even to curve and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent abrasion and an abnormal sound of a curved rack gear and a curved pinion gear caused by the occurrence of dislocation in a meshing reference with the curved rack gear by a phenomenon that a reference pitch circle of the curved pinion gear vertically causes pitching, in a driving device used for a lifting machine for curved stairs. <P>SOLUTION: The manufacturing method of this driving device manufactures the curved rack gear 1 by twisting in a curved shape after performing double helical cutting by an angle and a pitch of adding a correction corresponding to twisting in the curved shape to a straight line-shaped raw material, instead of manufacturing the curved rack gear 1 by cutting a curved-shaped raw material, and manufactures the corresponding curved pinion gear by performing helical gear cutting by an angle and a pitch of respectively doubling the angle and the pitch. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a rack gear and a pinion gear drive device that are also used in curved stair lifts and the like, and that corresponds to a curved line, and a method of manufacturing the same.

Conventionally, a linear rack gear that conforms to JIS standards is used for curved racks, and a spur gear that is a standard gear conforming to JIS standards is used. However, because their structure is simply a straight rack gear bent in a left-right curve, the pitch and angle in the curve are different, so these structures are simply a function of driving a spur gear, It does not have a function of smoothly driving the spur gear.

In addition, the following patent document 1 and the patent document 2 can be mentioned as a well-known technique relevant to this invention.

JP-A-6-286961 JP 2008-127202 A

Problems to be solved by the invention

This has the following drawbacks. The rack gear and pinion gear in the curve according to the prior art uses a rack gear that is simply bent in the left-right direction, and therefore has a function of driving the pinion gear and a function of smoothly driving the pinion gear. Therefore, in a rack gear with a curved shape, vibrations occur because the pinion gear always makes excessive contact with the left and right teeth inside the rack gear. At this time, the reference pitch circle of the pinion gear causes a shift in the meshing reference with the rack gear due to a phenomenon in which the reference pitch circle is pitched up and down. Therefore, the meshing with the spur gear is not smooth, and wear and noise are generated in the rack gear and the pinion gear. The reason is that the rack gear on the curve is different from the pitch of the rack gear on the straight line. It is necessary to change the pitch at the angle of the curve by the rack gear and the pinion gear. Also, since it varies depending on the angle of the curve and the size of the gear, the following manufacturing method should be used to maintain normal meshing so that unnecessary wear and vibration can be reduced in the rack gear and pinion gear. Is to do. Therefore, the present invention was invented to solve the above drawbacks.

Means for solving the problem

As means for achieving the above object, there is provided a manufacturing method of a rack gear and pinion gear drive device formed by double helical cutting. In addition, it is necessary to combine the gears produced by the manufacturing method. First, with rack gears that support curves, it is virtually impossible to perform rack gear cutting on a product with a curve in the left-right direction. Double helical rack gear cutting that can handle a product with a straight line as before is practically impossible. By providing it, the best curved rack is created when it is bent left and right after cutting. Along with this, a pinion gear that can handle a rack gear on a curve will also be provided.

The invention's effect

As described above, by combining a rack gear manufactured by a curved rack manufacturing method that can be applied to a curved line according to the present invention and a pinion gear manufactured by a curved pinion gear manufacturing method corresponding to the curved rack gear, the conventional method is used. Since the deviation of the meshing reference is eliminated and the rack gear and pinion gear in the curve can obtain the same effect as driving the rack gear on a straight line, the pinion gear can transmit normally, and the true value can be exhibited. Therefore, in addition to being able to reduce unnecessary wear on the rack gear and pinion gear, it was proved by trial that noise and vibration were reduced.

It is a perspective view on the appearance of the curve rack gear made into the curve concerning the 1st actual condition of the present invention. It is an external appearance perspective view of the curve rack gear which concerns on the 1st actual condition of this invention. It is an external appearance perspective view of the pinion gear corresponding to the curve which concerns on the 2nd actual condition of this invention. It is a meshing side view of the rack gear and the pinion gear in the curve concerning the 3rd actual condition of the present invention. It is an external appearance perspective view of the 1st cutting process in the straight line of the curve rack gear shown in FIG. It is an external appearance perspective view of the 2nd cutting process in the straight line of the curved rack gear shown in FIG. It is an external appearance perspective view after the cutting process in the straight line of the curved rack gear shown in FIG. It is an external appearance perspective view of the 1st cutting process in the pinion gear corresponding to the curve shown in FIG. It is an external appearance perspective view of the 2nd cutting process in the pinion gear corresponding to the curve shown in FIG.

Detailed Description of the Invention

When producing excellent gears, the design drawings and work drawings of gears are created by accurately performing various kinds of complicated calculations so that power can be transmitted without difficulty in the design. Next, based on this, in order to make sure that the on-site engineer designed the gears, we calculated the machine settings and then moved on to machining. Also, on-site workers can not only machine mechanically according to the posted drawings, but if they understand the overall characteristics and functions of the gears and engage in production work, excellent gears will be produced. .

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

1 to 2 relate to the first embodiment of the present invention, FIG. 1 is a perspective view of the completed appearance, and FIGS. 5 to 7 are perspective views of the manufacturing process.

First, in the curved rack gear manufacturing method according to the first embodiment, as shown in FIG. 1, the angle per tooth on the curve calculated with the calculated value must be corrected by the angle corresponding to the numerical value. Don't be. Here, the angle correction 1b is to twist the teeth. By performing the angle correction 1b, the reference pitch 1d needs to be changed to the pitch in the angle correction 1b. The reference pitch 1d is referred to as a reference pitch 1d (m · π) as a reference for the size of the gear teeth. The pitch for twisting the teeth is (m · π / cos β). Moreover, the calculated value differs depending on the size of the module (m) even at the angle 1e on the same curve.
A module is a value obtained by dividing the reference pitch by the circumference, which is called a module, and determines the size of the teeth. In general, it is expressed in millimeters, and in the inch size, it is expressed as a diamond pitch (DP25.4 / module).

The straight line product shown in FIG. 5 is processed by helical rack cutting (left direction) with the angle and pitch calculated by the calculated values. Thereafter, on the same tooth surface, the opposite helical rack cutting (right direction) shown in FIG. At that time, the reference tooth thickness 1a at the center of the rack gear tooth width 1c (the length in the tooth axial section is referred to as the tooth width) is not different from the reference tooth thickness 1a of the linear rack gear according to the JIS standard. With the reference tooth thickness 1a, the tooth thickness is referred to as tooth thickness and is represented by (m · π / 2).

Therefore, when the double helical rack gear cutting by the combination processing shown in FIG. 7 is performed, the tooth profile is corrected (the tooth profile is a diamond shape), so that when the rack gear in the linear shape shown in FIG. By making the left and right teeth parallel to the center of the curve, an ideal tooth shape is formed, and the teeth of the pinion gear reduce the excessive contact with the left and right teeth inside the rack gear.

FIG. 3 relates to the second embodiment of the present invention, FIG. 3 is a perspective view of the completed appearance, and FIGS. 8 to 9 are perspective views of the manufacturing process.

There is no conventional curve pinion gear manufacturing method in the second embodiment, and the angle 1b and pitch 1d calculated by the curve rack gear manufacturing method are used. However, the tooth width 2e of the spur gear used is driven by a rack gear on a curve, so that the rack gear 1 is compared with the tooth width 1c of the curve rack gear 1 with respect to the pinion gear 2. For this reason, the pitch 2b and the angle 2d of the curved pinion gear 2 are set to ½ of the numerical values used in the rack gear manufacturing method.

First, the pitch 2b and the angle 2d calculated above are processed by helical gear cutting (right direction) shown in FIG. After that, similar to the curved rack gear manufacturing method, the opposite helical rack cutting (left direction) shown in FIG. At that time, the reference tooth thickness 2c at the center of the tooth width 2e of the curved pinion gear is not different from the reference tooth thickness 2c of the spur gear according to the JIS standard.

Therefore, by carrying out double helical gear cutting by the combination processing shown in FIG. 3, the tooth shape is corrected (the tooth shape is a diamond shape), so that an ideal tooth shape is realized, and the curve shown in FIG. The teeth of the curved pinion gear reduce the excessive contact with the left and right teeth inside the rack gear. The diamond shape here is similar to the normal crowning shape, but is completely different. Crowning is called crowning to provide an appropriate bulge in the direction of tooth stripes.

FIG. 4 relates to a third embodiment of the present invention, and FIG. 4 is a side view in combination with FIG. 1 and FIG.

There is no gear alone. No matter what kind of gears you have, there is no point in having them. This third actual form is a technical method for enabling the mutual gears to be transmitted effectively and smoothly.

By combining the rack gear 1 manufactured by the curved rack gear manufacturing method described above and the pinion gear 2 manufactured by the curved pinion gear manufacturing method, the reference pitch circle 2a of the pinion gear and the reference pitch line 1f of the rack gear are centered. Since they intersect, there is no deviation in the meshing pitch circle shown in FIG. 4, and the same distance as the center distance of the standard gear can be maintained. As a result, it is possible to achieve the best engagement only by correcting the deviation based on the minimum engagement standard for making the gear look like a gear. The reference pitch circle 2a is a circle having a circumference that is a multiple of the number of teeth of the reference pitch 2b. The reference pitch circle 2a is a reference pitch line 1f. The thickness of the rack teeth is ½ the pitch. This is a specific pitch line. In order to change only the center distance, a dislocation gear is used, but even if it is used in such a curve, it does not make much sense. The shift gear is a gear in which the reference pitch line 1f of the reference rack is not in contact with the reference pitch circle 2a of the gear. Those shifted in the direction away from the gear are referred to as ten dislocations, and those shifted in the approaching direction are referred to as one dislocation. In addition, according to normal helical cutting, if the pinion gear is cut to the right, the rack gear must be cut to the opposite left, which causes thrust in the rotational direction. Thrust by rotation direction becomes uniform by cutting.
With the above description, the pinion gear can be normally transmitted to the rack gear and driven.

By the combination in this manufacturing method, the rack gear 1 and the pinion gear 2 in a curve are standardized as a preferable manufacturing method. As a result, the wear of the opposite gear is reduced, and abnormal noise and vibration are suppressed. When the sound is low, it means that it rotates more smoothly. Even if only one of the rack gear and the pinion gear is manufactured by this manufacturing method, an effect can be obtained, but it is halved compared to the effect obtained by the combination of the two. In addition to the effects on gear accuracy, there are various factors that cause gear noise, but the size of the meshing ratio is also greatly related. In addition, as described in the embodiment of the present invention, since it varies depending on the size of the gear, this manufacturing method can cope with the angle 1e of various curves and also supports both curves such as S-shape. As a result, the rack gear can be cut with a single product, so that the work at the time of assembling is easy and effective. Further, since the example of the helical cutting direction described in the embodiment for carrying out the invention is shown, the cutting may be performed from either direction.

Since the present invention relates to a curved rack gear, it can be used in the field of manufacturing L-shaped stairs, U-shaped stairs such as curved stair lifts, and inner and outer rack gears and pinion gears.

1 curved rack 2 curved pinion gear 1a reference tooth thickness 2a reference pitch circle 1b angle correction 2b reference pitch 1c tooth width 2c reference tooth thickness 1d reference pitch 2d angle correction 1e curve angle 2e tooth width 1f reference pitch line

Claims (2)

A drive device characterized by comprising a rack gear having a structure formed by cutting a double helical rack and / or a pinion gear having a structure formed by cutting a double helical gear so as to correspond to a curved line. A rack gear characterized by double helical cutting, in which helical cutting is performed in one of the left and right directions so as to correspond to the curve, and then helical cutting is performed on the same tooth surface in the other direction of the left and right. Or the manufacturing method of the drive device which manufactures a pinion gear.

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