JP2018062997A - Axis crossing gear device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gear device that has a simple mechanism and a wide range of axis crossing angles.SOLUTION: A device of this invention is a combination engaging gears 8, 9 comprising at least one pair of spur gears. A corner part 9a where a tooth tip circumferential surface of at least one gear 9 crosses with a side surface or side face is formed in a chamfering shape by applying R. The corner part 9a with R is engaged with the other gear 8, and thereby an axis center of the pair of gears 8, 9 is formed by crossing O, Oon the same plane. The corner parts 8a, 9a where the tooth tip circumferential surface of a pair of both respective gears 8, 9 crosses with a side surface or side face can be formed in the chamfering shape by applying R, and the corner parts 8a, 9a formed in the chamfering shape of the pair of gears 8, 9 can also be engaged with each other.SELECTED DRAWING: Figure 3

Description

  The present invention mainly relates to a cross-axis gear device suitable for light loads.

  Conventionally, bevel gear mechanisms, helical gears, worm gear mechanisms, etc. are known as gear transmissions with crossed shafts, but these all require their own gear machining as general machine parts, and machining costs Becomes too large. For this reason, for example, a low-cost gear transmission mechanism has been sought for a gear for counters of instruments used for light loads, gears for operating devices, transmission gears for light-weight items, and the like. Moreover, what is shown by patent documents 1 and 2 is proposed as a cross-axis type gear apparatus suitable for these.

JP 2009-150524 A (FIGS. 7 and 22) JP-A-5-123922 (FIG. 1)

  In the invention of the above-mentioned Patent Document 1, one of the peripheral surfaces of the pair of gears is formed into a drum shape by curving an intermediate portion in a valley shape, and the other is formed into a drum shape by curving into a chevron shape that matches the curve. The outer peripheral surfaces are engaged with each other between a mountain shape and a valley shape. In addition, as shown in FIGS. 7A to 7C of the document 1, the gear shafts are shown in a case where they intersect on the same plane in addition to a parallel case. Further, FIG. 22 of the same document shows a case where the gears are helical gears and intersect three-dimensionally.

  The pair of gears according to the invention of Patent Document 1 has a shape in which one of the outer peripheral surfaces is a mountain-shaped arc in the width direction and the other is a valley-shaped arc, and the arcs of both teeth overlap each other. However, in a normal gear, the module is determined by the diameter of the gear and the number of teeth, but if the diameter changes in the axial direction with a single gear, the module changes at the center and end face in the width direction, and the drum-shaped gear And the drum-shaped gear, the modules do not match at the center position in the width direction, and the pitches of the tooth tips and the tooth roots (bottoms) to be engaged with each other are different. In this case, normal meshing of the gears becomes impossible.

  7 (a) and 7 (c) of the same document, the gear diameters at the meshing positions can be matched or the modules can be matched, but in order to make them coincide, precise control of the crossing angle of the shafts is possible. In addition, gears of specific specifications that have already been geared or honed can only be applied at a predetermined crossing angle corresponding to a gear circumferential angle chevron or valley arc, and at least 90 ° There is a restriction that it cannot be used at close axis crossing angles. In addition, such a gear has a drawback that a special hob and a processing method are indispensable, and it is not practical.

  Next, in the invention of Patent Document 2, one of a pair of gears is a spur gear, and the other is geared to the outer periphery of the disc-shaped gear body and the outer periphery of both side surfaces. The crossing angle is 0 ° (parallel) to 90 °, but also in this invention, the gear on the outer peripheral surface side of the gear is similar to the above in the one gear that has been geared on both sides. The gear diameter is different for the teeth on the center side of the side surface (Note: The teeth on the side surface of the gear body 2 are formed in a sector shape or a radial shape from the axial center in the side view), so the modules are different at both positions. Proper meshing of both gears at all positions in the range is difficult or impossible.

  If the meshing in the above range is realized, it is necessary to set the pitch of the spur gear and the pitch of the other gear in a range that does not contradict each other, which is practically impossible or extremely difficult. Is not understood. Further, as is apparent from the drawings, there is a drawback that special gear cutting (hob) is required to perform gear cutting on the peripheral surface and the outer peripheral edge of the gear.

The apparatus of the present invention for solving the above-mentioned problem is a combination of firstly engaging gears 8 and 9 comprising at least a pair of spur gears, and the tooth peripheral surface and side surface of at least one gear 9 or A corner portion 9a intersecting with the end surface is rounded to form a chamfered shape, and the corner portion 9a having the rounded portion is meshed with the other gear 8 so that the axes of the pair of gears 8 and 9 are O _1. , O ₂ intersect with each other on the same plane.

  Secondly, the corner portions 8a and 9a where the tooth tip circumferential surfaces and the side surfaces or end surfaces of the pair of gears 8 and 9 intersect each other are formed in a chamfered shape with a rounded shape. .

  Third, the corner portions 8a and 9a formed in a chamfered shape of the pair of gears 8 and 9 are engaged with each other.

Fourthly, when the gears 8 and 9 are engaged, the teeth C ₁ and C ₂ of the gears are brought into contact with each other at a pitch point P ₀ on the pitch circles P ₁ and P ₂ .

  Fifth, it is characterized by chamfering the end surfaces or side surface side corner portions 8b, 9b of the tooth bottoms of the gears 8, 9.

According to the gear device of the present invention configured as described above, the following effects can be obtained.
(1) Standard spur gears are sufficient for all the gears of the cross-gear type gear device, so gear cutting and honing can be easily performed at low cost, and the outer periphery and end face of the gear cross section Or by attaching a radius to the corner part with the side surface, even if meshed in a crossed state, the toothed part of one gear angle does not contact the toothed surface of the other gear, and the other toothed surface is damaged. The gear life can be maintained.

(2) Since the spur gears mesh with each other while maintaining the same module, gear transmission is smooth, and even for small loads, it is easy to withstand relatively high torque, and over a wide range of crossing angles including 90 °. Combinations are possible.

(3) By forming the cross-sectional corner portions of both of the pair of gears in a rounded shape, the corner portions can be engaged with each other, and the crossing can be performed in a wide range of the crossing angle of 0 ° to 180 °. Further, the meshing of the two gears is such that the arc-shaped surfaces mesh with each other at a pitch point, thereby enabling efficient and smooth gear transmission.

(4) Also, by chamfering the corner portion between the side surface or end surface of the gear and the end portion of the tooth bottom surface, the end corner of the tooth bottom surface when engaged with the shaft intersecting with each other interferes with the tooth tip of the other gear. This is advantageous in that the selection range of the crossing angle and crossing position of the gear shafts is widened.

It is a whole front view at the time of carrying out a trial manufacture experiment of the gear apparatus of this invention. It is a right view of the gear apparatus of this invention. It is a plane sectional view showing the gear meshing state of the gear device of the present invention. It is an expanded plane sectional view which shows the meshing state of a gearwheel. It is VV sectional drawing of FIG. (A)-(E) is a top view which shows the combination state of the gearwheel which makes an axis crossing angle 0 degree (parallel), 45 degrees, 90 degrees, 135 degrees, 180 degrees (parallel).

  The drawings show an embodiment of a trial production of the gear device of the present invention. The device has a plate-like base 1 and a pair of block-like bearing portions 2 and 3 in the orthogonal direction in plan view by bolts 4 or the like. Gears 8 and 9 made of spur gears have the same height and can rotate freely in the direction orthogonal to each other in a plan view by shafts 6 and 7 It is supported and is prevented from coming off by a snap ring (C ring) 5 or the like.

In the gears 8 and 9, the corner portions of the end surfaces (or side surfaces) and the peripheral surfaces (tooth surface) of the teeth mesh with each other, and the corner portions 9a and 8a of the gears 8 and 9 are For example, it is chamfered to a radius with a radius equal to or greater than the tooth height when viewed from the outer circumferential direction, and when engaged with each other, the end corner of one gear is the tooth surface of the other gear. It is formed in a shape that does not damage by contacting (interfering) with the tooth bottom surface. Further, the meshing between the gears 8 and 9 is similar to that of a normal gear, with the pitch point P ₀ (see FIGS. 4 and 5) at which the tooth surfaces corresponding to the maximum torque intersect the pitch circles P ₁ and P _{2 of the} gear. ), It is desirable to make point contact with each other arcuate chevron surfaces.

In the example shown in FIGS. 1 and 2, a large-diameter operation wheel 11 for rotationally driving the gear 8 is disposed behind the gear 8 on the shaft 6 having a longitudinal axis O _{1 serving} as a driving side gear. A shaft is mounted so as to rotate integrally with the motor 8. In this example, the driven side gear 9 is rotationally driven by the driving side gear 8 by rotating the operation wheel 11 manually or by belt transmission. The corner portions 8a of the case both gears 8,9, because 9a is formed in the round shape, even meshes intersect is and gears crossed axes angle theta ₁ is secured in a wide range including 90 ° Since they mesh with each other smoothly and do not interfere with the tooth surfaces and bottoms of other gears, they are not damaged.

In the gear having the cylindrical shape remaining at the base end portion shown in this embodiment and forming the teeth C ₁ and C ₂ only on the tip end side, an axis crossing angle θ ₁ is obtained up to 90 ° as shown in FIG. adjustment range theta ₂ of the crossing angle theta ₁ towards obtain near 80 °. The case where full width gear cutting is performed will be described in detail in FIG.

4 and 5 show an enlarged plan sectional view and a VV sectional view when the gears 8 and 9 of FIGS. 1 to 3 are engaged with each other at right angles, and the teeth C ₁ and C as described above. ₂ corners 8a, meshing contact of the maximum torque at 9a is the pitch point _{P 0.}

Further although not necessary in engagement this, as in the case of axial crossing angle theta ₁ is shown in FIG. 6 (B), (D) , for example with respect to the drive gear 8, when tilting the driven gear 9 45 ° before and after each other Since there is a case where the tooth bottom end portion of the gear and the corner portion of the tooth tip side end interfere with each other, it is desirable to chamfer or chamfer so that the corner portions 8b and 9b are rounded.

Figure 6 is the case of crossing in a range of axial crossing angle theta ₁ is 0 ° when engaging the gear 8,9 gear teeth are formed on the entire peripheral surface (parallel) to 180 ° (parallel to the butted allowed direction) Is shown. In each of the drawings shown in FIGS. 9A to 9E, the corner portions 8a and 9a of both gears 8 and 9 are engaged with each other. It is also possible to mesh the corner portion 9a of the gear 9. When the axis crossing angle θ _{1 at} that time is around 45 ° or 135 °, the tooth tip of the gear 8 may interfere with the tooth bottom surface of the gear 9. The chamfering can avoid the interference. Further, when the tooth tip corner portion 8a of the gear 8 is meshed in the middle of the peripheral surface of the other gear 9, the corner portion 8b at the bottom end of the gear 8 may be chamfered in a round shape.

  The corner portions 8b and 9b on the tooth bottom side are arranged at the corners of the side ends of the gears 8 and 9 by NC control or the like at the end of gear cutting (hobbing) on the side surfaces of the gears 8 and 9. Can be rounded and chamfered according to the arc, and no special hobbing or hobbing is required. In terms of processing, it is more convenient that the corners 8b, 9b on the tooth bottom side are concentric with those on the corners 8a, 9a on the tooth tip side.

  Further, the gear teeth on the side surfaces of the gear corners 8b and 9b can be cut only at a very limited depth at the periphery with respect to the gear shaft center. When it is close to, other teeth adjacent to the hob blade are cut and removed.

  In addition, in the above example, an example in which a rounded chamfer is formed on only one side surface of the spur gears 8 and 9 is shown. However, both corners 8a, 9a, 8b, and 9b on both the tooth tip side and the root side end are shown. It is also possible to chamfer the gears, and the gear itself is not necessarily gear-cut and can be formed by cold forging, sintering molding, plastic molding, or the like.

8,9 gear 8a, 9a tooth tip surface or side surface of the corner portion 8b, the corner portion C ₁ of 9b tooth bottom end, _{C 2} teeth O _{1, O 2} axis P ₀ pitch point P _{1, P 2} pitch circle θ _1- axis crossing angle θ _2- axis crossing angle adjustment range

Claims (5)

A corner portion (9a) that is a combination of at least one pair of spur gears (8) and (9) meshed with each other, and the tooth peripheral surface and the side surface or end surface of at least one gear (9) intersect. Is formed into a chamfered shape, and the corners (9a) with the above-mentioned radius are meshed with the other gear (8), whereby the axes of the pair of gears (8) and (9) are (O ₁ ) A cross-axis gear device obtained by crossing (O ₂ ) on the same plane.   The corner portions (8a) and (9a) where the tooth tip circumferential surface and the side surface or end surface of each of the pair of gears (8) and (9) intersect are rounded and formed into a chamfered shape. Item 3. The cross-axis gear device according to item 1 or 2.   The cross-axis gear device according to claim 2, wherein corner portions (8a) and (9a) formed in a chamfered shape of the pair of gears (8) and (9) are meshed with each other. When the gears (8) and (9) are engaged, the gear teeth (C ₁ ) and (C ₂ ) are brought into contact with each other at a pitch point (P ₀ ) on the pitch circles (P ₁ ) and (P ₂ ). The cross-axis gear device according to any one of claims 1 to 3.   The cross-axis gear device according to any one of claims 1 to 4, wherein the end surfaces of the tooth bottoms or the side surface side corner portions (8b), (9b) of the gears (8), (9) are chamfered.

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