JPH04300119A - Surface gear generation device - Google Patents

Abstract

PURPOSE:To obtain a generating device capable of generating gear teeth of a surface gear successively by reciprocating a tapered rotating tool and bringing the surface of a work close to a tool line while giving a rotational and swing movements equivalent to those of the surface gear of a surface gear mechanism in which a work is assembled. CONSTITUTION:A surface gear type cradle unit 7 to which a work 10 is fixed is provided on a back swing table for a rotating gear 5 which can be fixed at a fixed position and a surface gear 6 which is fixed to an inclined shaft 12 through roller bearings. Then gear grooves in the same number as the surface gear 6 or even-divided number of gear grooves are generated in the work 10 with a cutter 11 by driving the inclined shaft 12. Also an involute curve tooth which is formed by generating the section of teeth at right angle relative to the gear by a rack type tool can be obtained. By generating the gear teeth repeatedly while changing meshed phase of the gear 5 relative to the tool line, the width of the grooves can be unified into the maximum pitch of a master gear and gear teeth with small pitch error can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial application field The present invention mainly relates to the gear cutting of a face gear of a face screw gear mechanism in which the cross section perpendicular to the meshing teeth is created into a convex involute tooth profile by a rack-shaped tool, and the continuity of the tooth profile. It is related to the creation device.

(B) Conventional technology A gear with teeth on a convex conical inclined surface is called a bevel gear, and a gear with a pitch cone angle of 90° is called a front gear or a crown gear. Since gears other than internal gears were rarely put into practical use, they were treated as special deformed gears. Conical gears are also similar to bevel gears, and their tooth profile was created using a bevel gear generating gear cutting machine.

However, now that surface screw gear mechanisms have begun to be put into practical use, it has become necessary to define a conical gear.

A face gear has gear teeth on a conical slope (A) with a pitch cone angle (hereinafter abbreviated as P1A1) of 60
(B) Those with P1A1 of 60° or more but less than 75° are considered convex face gears. (C) Those with P1A1 of 75° or more and less than 90° are simply called face gears.

(D) Also, only those with P1A1 of 90 degrees are defined as front gears or crown gears as before. (E) Those with P1A1 of 90 degrees or more are defined as concave face gears.

This type of conical gear has straight (or oblique) bevel gears with gradually increasing gears radially extending from the apex of the cone. Normally, an indexing device is used to coarsely cut the teeth, and then the cutter line is oscillated to reach one tooth. The method used was to create one or both sides of the mountain.

However, the tooth profile of a bevel gear provided on a two-dimensional conical curved surface cannot achieve accurate meshing unless the cross section perpendicular to the tooth is a two-dimensional or spherical tooth profile, but due to the shape and structure of the tool, conventionally this type of tooth profile is not possible. Tooth profiles had not been put to practical use.

For this purpose, a rack-shaped tool is used to create a gradually increasing tooth profile or a conically curved tooth profile (called a CONIFLEX tooth profile under the Gleason company name) whose cross section perpendicular to the tooth is an involute curve in one dimension. The method used was to give the teeth an appropriate amount of contact by applying a sanding finish.

Conventionally, there has been no method of creating straight (beveled) tooth flank gears, especially offset flank gears, that does not use an index, other than a continuous generation finishing device using a base lap.

References - Shinkle gear technical data, time S56-15
Note No. 6366: A deviation plane gear is a plane gear with a progressive tooth profile in which the pitch cone apex is different from the apex of the conical inclined surface (CONICALFACEAPPEX), and the pitch cone apex is inside the conical apex. is defined as a positive (+) deviation.

The amount of deviation is expressed by the diameter or radius of the circle formed by the respective intersection points.

(c) Problems to be solved by the invention In a surface gear mechanism, surface gears with a small difference in the number of teeth are tilted and meshed until their respective pitch lines coincide, and the surface gears are meshed to form a surface gear, and the rotation ratio of each gear is utilized. It is.

In order to align the pitch cone apex of two face gears with equal tooth sizes (called modules) and different numbers of teeth with the center of swing, concave and convex face gears must be used. In this case, the tooth profile is a non-commutable face gear with a rack and a convex or convex tooth profile curve.

In particular, in a facing gear mechanism (called a sinkle gear) that has two sets of surface meshing parts on the same axis, if this type of offset surface gear is not used, the load on the surface gear bearing will be large, and a stronger one is not advantageous. I can't do it.

In addition, the surface gear of a surface helical gear mechanism uses a method like the conventional bevel gear, in which the division of the tooth space is determined by an index and then created individually for each tooth. A model gear with a permissible index where the surfaces are in point contact (
MASTERGEAR) pitch and tooth profile errors are reproduced on the gear teeth of the machined gear.

However, this pitch error has no wear-in reduction property, and the elastic deformation of the mechanism and the play value accumulate, concentrating on one tooth, and increasing the width. There is also a method of modifying the tooth contact surface by lapping, which can correct the adjacent pitch error to some extent, but on the other hand, the cumulative pitch error cannot be reduced because the tooth profile collapses. For this reason, surface spiral gear mechanisms and sinkle gears that use the pseudo tooth profile of bevel gears have large noise, vibration, and angular velocity fluctuations, are difficult to manufacture, and are inefficient, so they have many characteristics compared to other gear mechanisms. However, it has hardly been put into practical use except for special purposes.

(d) Means for solving the problem A surface gear tooth profile with a radially increasing tooth profile on a conical surface must be created using a tool with a crown tooth profile, but it is difficult to move a multi-blade rotary tool in the tooth trace direction.

For this reason, in the present invention, a tapered rotary tool with a constant pressure angle is reciprocated, and the surface of the workpiece is given the same rotation and oscillation motion as the surface gear of the surface gear mechanism in which the workpiece is installed, relative to the tool line. By moving the tool closer to the tool line, the tooth of the face gear can be created continuously. The cradle unit that attaches the workpiece is the same as the surface gear mechanism into which the workpiece is installed, and the tooth profile of the master gear is reproduced on the workpiece, but if the generating motion is repeated while changing the meshing phase of the surface gear with respect to the tool line, The pitch errors of the master gear are unified to the maximum value. When the pitch error of the tooth profile created on the workpiece surface is reduced, it can be used again as a master gear to obtain a face gear with higher precision. By relatively moving the tool and workpiece positions, the root line deleted by the tool line can be used as a free-form convex curve to modify the tooth profile in the direction of the tooth root to a convex conical curved tooth profile, or to change the root cone angle. It can be changed arbitrarily. Furthermore, by changing the axis of the cradle perpendicular to the tool line around the pitch point of the tool, the tip of the tooth can also be modified.

(e) In order to have the same oscillation motion as the surface gear of the surface spiral gear mechanism in which the workpiece is incorporated, the oblique shaft (12) of the cradle unit is required.
The synclinal angle Σ° must be twice the complementary angle of the pitch cone, but in consideration of the elastic deformation of the tooth profile, it is set as the complementary angle of the root cone (half apex angle of the back cone). The rotating surface gear (5), which can be fixed at any position, is meshed with the surface sliding gear (6), which is attached to the oblique shaft (12) via a rolling bearing, and the workpiece (10) is mounted on the rocking table on the back side. Fix it so that the center of swing (0) is at the fixed position. Let the number of teeth of the workpiece to be created now be Z1, the number of teeth of the mating gear that meshes with it be Z2, the module at reference points P, C, and D be m, and the synclinal angle of the oblique axis be Σ°. (a) The distance from the swing center (0) to the tool line at the maximum depth of cut is (Z1-Z2) m/2sinΣ゜ (mm) (b) The workpiece (10) is installed in the plane gear mechanism. The center of oscillation of the workpiece when the workpiece is a plane gear, that is, Z1>
When Z2, it coincides with the center of oscillation (0) of the plane gear (6). When the workpiece is a rotating surface gear, that is, when Z1<Z2, it is on the opposite side, but in this case, the tool becomes the tooth of the mating surface gear, so it must be in the same position as when Z1>Z2.

(c) If the number of teeth of the rotating plane gear (5) attached to the rocking table (7) is N5, and the number of teeth of the plane gear (6) is N6, the rotating plane gear (5) swings from the conical apex P5. Distance to center (0)■〓■5=(N6-N5)m/2sinΣ゜plane gear (
In order to mount the workpiece (10) on the back side of the workpiece (10) so that the swing center (0) is in the fixed position, the number of teeth N5 and N6 must be set to Z1.
, it is necessary to increase the interval by making it an integer multiple of Z2 or by increasing m. Here, when the autorotating plane gear is fixed and the oblique shaft (12) is rotated, the plane gear (6) swings once per rotation of the oblique axis and rotates at a ratio of N6-N5/N6. Mechanically, N6>N5 must be satisfied, so the surface gear (5
) is in the same direction as the rotation of the oblique axis. On the other hand, the tool should have a tapered rack shape that is equal to the pressure angle of the tooth profile to be created, and should be given reciprocating motion in a direction perpendicular to the axis X-X (if it is a rotary tool, the spindle should be reciprocated). The line is called a tool line.

When the workpiece (10) attached to the back surface of the surface gear (6) is brought close to the tool line, grooves are carved on the workpiece surface by the tool at a jump of the number of teeth (Z1-Z2). The meshing right-angled tooth profile curve of the tooth formed between these grooves becomes an accurate involute curve created by a rack-shaped tool.

By moving the rotating surface gear (5), the groove width is expanded to a predetermined tooth width. The tooth profile of the face gear created by this rack-shaped tool is an exchangeable convex involute curve. ) can mesh with the mating face gear Z2 and rotate about the center of oscillation, or can rotate about its axis.

When creating a shifted surface gear, a convex multidimensional involute tooth profile with the same shape can be created by shifting the tool line by equal positive and negative amounts.

By appropriately shifting the tool position upward or downward from the center line XX, a bevel gear can be obtained.

A surface spiral gear mechanism using an involute tooth profile has a feature that a back gap can be eliminated because it can achieve negative displacement and preload engagement (fixed position or constant pressure). For this reason, the surface gear (6
) No vibration damage occurs even when heavy cutting is performed directly on the workpiece attached to the back of the machine. It is efficient because reciprocating cutting (UP & DOWNCUTTING) can be performed using milling cutters rotating in the same direction, and two grooves can be created per swing using parallel spindles. Note that cutting can be performed using a reciprocating tool or a milling cutter, or finishing can be performed using a grindstone or lap base after heat treatment.

In this mechanism, the number of teeth N5, N6 and the difference in the number of teeth (N6-
N5) is the workpiece tooth number Z1, Z2 and the difference in the number of teeth (Z1-Z
Since there is a constraint that it must be equal to 2) or an integral multiple thereof, it is incompatible and has the disadvantage that it is difficult to design a powerful one. In addition, when generating processing is performed with the rotating surface gear (5) fixed, the pitch of the teeth of the generated workpiece (10) is The pitch of the surface gear (6) is reproduced. This pitch error cannot be reduced even if generation is repeated, so the oblique axis 1
During rotation, the rotational surface gear (5) must be reversed by a fixed amount so that the rotation ratio of the surface gear (6) becomes the difference in the number of teeth/the number of teeth.

(F) Embodiment Figure 1 shows the oblique shaft (2) of the reversible sinkle gear connected to the rocking table (7).
) and the driven surface gear (4) of the surface gear mechanism are connected to the rotating surface gear (5), respectively. ) Cross-section of the single gear type cradle unit that drives the (
FIG.

The number of teeth of the rotation surface gear (1) of the sinkle gear part is N1, the number of teeth of the surface gear (3) is N2, N3, the number of teeth of the driven surface gear (4) is N4, and the rotation surface of the rocking table (7). The number of teeth of gear (5) is N
5. If the number of teeth of the plane gear (6) is N6, the oblique shaft (2) (
In this case, the rotation ratio between 12) and the surface gear (6) is the number of teeth of the surface gear part N5, N6 is the number of teeth of the workpiece Z
1, can be determined freely regardless of Z2.

N6=60, N5=60 to lengthen O-P5 interval
If -4=56, then N5/N6=56/60=14/1
5, so in order to obtain 1/R=difference in number of teeth/number of protruding teeth=(N2-N1)/N2, set N3/N4=N6/N5.

If N4=N5/2=56/2=28 N3=N6/2=60/2=30, the number of index teeth Z1
=67 When tooth number difference Z1-Z2=67-65=2, N2=Z1=
67 N1=67-2=65.

The workpiece (10) rotates by 2/67=1/36.5 for each swing. The tooth groove is carved into one tooth jump, 67 x 2 = 134
67 teeth are created by rocking.

In this case, the surface gear (3) of the sinkle gear is the rotating surface gear (
1) When fixed, N2-N1/N2=67-65/67=
2/67 same rotation. This is the rotation ratio of the workpiece (10) 2/6
Same as 7. In this case, the pitch error of the workpiece gear is N
Affected by pitch error of 2 teeth. However, in a surface gear mechanism, the pitch error of each surface gear appears as an adjacent pitch error, but does not become a cumulative pitch error. Due to this property, in this mechanism, the meshing errors of N1 and N2 parts are N3 and N3.
This is compensated by the surface sliding engagement of the parts 4, N5, and N6. That is, when the generating motion is repeated, the resulting groove width is unified to the maximum error of the meshing teeth. Therefore, the pitch error of the generated tooth ridge approaches zero value as generation is repeated. Although this method is necessary when making a model gear (master gear) for a machine tool, it is inefficient. In order to obtain high-precision gears by reducing the number of repetitive machining operations possible, it is possible to increase the pitch accuracy of the master gear, or to sequentially shift the meshing phase with respect to the tool line. We must avoid creating them.

In the previous example Change as follows.

If N1 is fixed and a generating motion is applied, the meshing phase of each face gear with respect to the workpiece gear can be deviated to a fixed amount, but it is not possible to generalize because the tooth of the full face gear must be changed according to the set number of divisions. hard.

Furthermore, since the rotating surface gear (1) must be fixed during generation, a constant tooth on the opposite side to the tool line serves as a reference, so it cannot be used except in special cases. Example(
2) Figure 2 shows the oscillating joints (17) and (18) on the surface gear (3) of the sinkle gear section (reference document, patent application S59-04878).
No. 4), and the outer periphery of the swing joint (18) and the rotating surface gear (1) can be fixed at any position using the brakes (19) and (20).

The operation will be described assuming that the number of teeth N1 to N6 of each face gear is the same as in the previous embodiment.

When the rotating surface gear (1) is fixed with the brake (20) and the brake (19) of the swing joint (18) is released and driven, the workpiece (10) swings 67 x 2 = 134 and moves 67 times. A groove is carved. Before and after this, the swing joint (18) is fixed by the brake (19), and when the brake (20) is released and the rotating face gear (1) is idled, the workpiece (10) only swings but does not rotate. From this, the tool (11) creates the same tooth surface of the workpiece, and the rotating surface gear idles. When the rotating surface gear (1) idles at a fixed angle, the brake (19) is released, and when the rotating surface gear (1) is fixed by the brake (20), the rotational component is again given to the workpiece, and the master gear is shifted to a different phase. The creation will continue with this as the standard. The groove width increases during machining, brake (19), (
20) at the same time to allow the rotating surface gear (1) to idle as appropriate. To create a tooth, the tooth surface in the direction of rotation of the workpiece engages with the tool, and the opposite side is removed and removed, but in the case of a radially increasing tooth profile of a face gear, the workpiece is reversed and the opposite side of the tooth is created. Must.

Automation can be easily achieved by adjusting the groove width at the time of this reversal.

Face gears are usually made of alloyed copper, and their teeth are elastically deformed by surface pressure during power transmission, so interference will occur if the tooth profile curve is not corrected. In the case of face gears, it is especially necessary to crown the teeth in the tooth trace direction.

In each embodiment of the present mechanism, the modification in the tooth profile direction increases the oblique angle Σ° of the oblique axis to the complementary angle of the root cone. For large, high-capacity models, a tool with a large taper angle is used to modify the tooth tip.

For modification in the direction of the tooth trace, by relatively moving the positions of the tool and the workpiece, the bottom line of the tooth can be made into a convex curve to form a conically curved tooth profile. In the case of offset surface gears, since the pressure angle of the inner gear gradually increases, the inner width of the tooth groove can also be increased by shifting the tool position with respect to the center of the workpiece.

(G) Effects of the Invention The workpiece (10) is mounted at a fixed position from the center of oscillation (0) of the cradle unit, and the gear generating surface of the workpiece is given a motion equal to that of the surface gear in which the workpiece is incorporated. When approaching the tapered tooth tool line with a constant pressure angle, a division number of tooth ridges equal to the denominator of the rotation ratio is created for each number of molecules and one groove for each oscillation. The meshing right-angled tooth profile of a regular face gear created when the tool line is aligned with the center of oscillation (0) is a convex involute quadratic curve created by a rack-shaped tool, but for a shifted face gear, each The conical apex of is offset from the conical apex of the mating face gear by (number of teeth difference) × (module), so the side of the face gear with fewer teeth is positive.
The meshing right-angled tooth profile of the face gear, which is created using a rack-shaped tool with a constant pressure angle, is created by a rack-shaped tool with a constant pressure angle in order to deviate the face gear side with a large number of teeth by an equal amount and match the pitch cone angle. This results in a convex involute curve that is equal to the pressure angle of the tool, but
The pressure angles of the meshing cross-section tooth profiles at fixed points in the tooth trace direction that mesh at the same position from the swing center (0) are different. In other words, the tooth profile becomes a so-called convex involute multidimensional tooth profile, which is a convex conically curved surface in the direction of the tooth trace. There is no need to analyze this kind of tooth profile here, but in short, a shifted plane gear must be used in a plane gear mechanism in which identical convex involute tooth profiles mesh with each other, and this shifted plane gear is created. For this purpose, a method is suitable in which the tooth profile is created continuously by applying rotation and oscillation to the workpiece using a surface spiral gear mechanism.

However, with this method of creating face gears using a cradle unit, the number of teeth and tooth profile created on the workpiece surface differs due to the difference in the number of teeth between the master gear gear and the mating gear, so it is less compatible and versatile. There is.

However, all cradle units are composed of face gears, and since face gears can be created using cradle units, there are advantages to improved precision through repeated machining and mass production. Next, the surface spiral gear mechanism has the characteristic that no cumulative pitch error occurs.

In particular, in the case of a continuous generation method such as the book cradle unit, in which the groove width is expanded by reversibility while finishing both sides of the tooth, no cumulative pitch error occurs. By displacing the meshing phase with respect to the tool line, the adjacent pitch error of the master gear is also reduced as machining is repeated.

The meshing between identical convex involute tooth profiles created by a rack-shaped tool is achieved by rotating the meshing double-sided gears by the same amount in the forward direction, as the meshing progresses at the same angular velocity even if the meshing pitch point changes, allowing for constant rotation. The surface can be bent by applying preload. Therefore, the meshing back gap can be eliminated and the wear of the gears can be compensated for (Reference document, Quantum Pressure Type Surface Screw Gear Mechanism, Patent Application No. 59-048783). Even if the workpiece (10) is subjected to heavy cutting with a multi-blade tool, no vibration or impact damage will occur, so efficient machining can be performed.

In a face gear mechanism, the pitch error of the face gear causes noise, vibration, angular velocity, and fluctuation, which adversely affects performance, but this pitch error is unavoidable in the conventional independent generation method using an index. Adjacent pitch errors can be corrected by lapping, but on the other hand, the tooth profile collapses and the angular velocity fluctuates. However, since adjacent pitch errors accumulate on one tooth surface, a highly accurate surface screw gear mechanism cannot be obtained.

On the other hand, in this continuous generation method of face gears using this cradle unit, as long as the workpiece (10) oscillates around the oscillation point (0), the adjacent pitch error is affected by the master gear, but no cumulative pitch error occurs. . That is, the workpiece (10) reliably rotates once with the reciprocal rotation ratio of the oblique shaft (12). Adjacent pitch errors can be reduced by repeating the generation while changing the phase of the master gear relative to the tool phase.

If tooth profile modification is necessary, the tooth profile involute curve can be easily modified by changing the distance between the swing center and the tool line, and the tooth tip curve can be modified by changing the tool pressure angle.

Further, the tooth profile in the tooth trace direction can easily be made into a conical curved tooth profile by controlling the relative position of the cradle axis XX and the tool to N, C, according to the curved coordinates.

This cradle unit can be used not only to create gradually increasing deviation straight face gears for face slope gears, but also to create bevel gears, bevel gears, concave involute face gears, and face gears. There are many.

[Brief explanation of the drawing]

Figure 1 is a longitudinal cross-sectional view of the single gear type cradle unit when each face gear is in mesh at its maximum meshing position. Figure 2 is a vertical cross-sectional view of the single gear type cradle unit when each face gear is in mesh with the maximum engagement position. FIG. 2 is a structural diagram in which a set of brakes that can restrain the outer circumference of the joint at an arbitrary position are installed. Figure 3 is a plan cross-sectional view of the workpiece relative to the tool line;
The figure is a front view of the same.

Claims (3)

[Claims] Claim 1: A workpiece (10) is mounted on the back rocking platform of a rotating surface gear (5) that can be fixed in a fixed position and a surface sliding gear (6) that is attached to an inclined shaft (12) via a rolling bearing. The surface gear type cradle unit (7) fixed with the rotating surface gear (5)
is fixed and the oblique shaft (12) is driven, while the unit axis
-On the tool line Y-Y perpendicular to X, there is a plane gear (6).
A tooth groove with the same or equal number of divisions as the gear is carved. When the groove width is expanded by deflecting the rotating surface gear (5) in the radial direction, the cross-section perpendicular to the tooth of the gear formed by these grooves becomes a convex involute curve created by a rack-shaped tool. It becomes a tooth shape. By repeating gear creation while changing the meshing phase of the rotating surface gear (5) with respect to the tool line, the groove width is unified with the maximum pitch of the master gear, making use of the characteristic of obtaining gears with small pitch errors. Continuously generating gear cutting and finishing method for face gear tooth profile using a face gear type cradle unit. [Claim 2] A diagonal shaft (2) of a reversible single gear that is capable of fixing an autorotating surface gear (1) at an arbitrary position to the surface gear type cradle unit according to claim 1.
) to the output shaft of the drive reducer (13) and the oblique shaft (12) of the cradle unit (7), and the driven plane gear (4) to the rotation plane gear (5), respectively, to create a oscillating table. (6
) and the number of teeth N5 of the rotating surface gear (5) in the workpiece (
10), the number of teeth Z, and the difference in the number of teeth of the mating gear (Z1
- For creating a face gear, which is characterized in that an appropriate number of teeth and a difference in the number of teeth can be obtained regardless of Z2), and the meshing phase of each face gear is sequentially deviated with respect to the tool line Y-Y during operation. Single gear type cradle unit. [Claim 3] Rotatable rocking joints (17) and (18) are provided on the outer periphery of the surface gear (3) of the single gear type cradle unit according to claim 2, and the drum portion (
Brakes (19) and (20) that can fix the outer periphery of the surface gear (18) and the rotating surface gear (1) at arbitrary positions are installed, and the surface gears (3), (6) and the workpiece are attached during operation. (10)
The rotation component of the brake is stopped by the brake, the rotation plane gear (1) is idled, and the meshing phase of the master gears (1) and (2) is deviated by a fixed amount, and the brakes (19 and 20) are simultaneously stopped. A sinkle gear type cradle unit for creating a face gear, which can adjust the groove width created on a workpiece (10) by opening it.