JPH06297243A - Cylindrical grinding worm for roll grinding of spurgear - Google Patents

Abstract

PURPOSE: To simplify the balancing of a grinding worm. CONSTITUTION: A grinding worm has worm teeth 4 terminated at the radial fronts 7, 8 on both sides without using a taper ring. A space (b) between both fronts 7, 8 is odd integer times as large as the half of a lead (t) of the worm. Since the grinding work is formed in such a manner, the rebalancing of the worm when used later is remarkably simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical grinding worm for roll grinding of spur gears.

[0002]

2. Description of the Prior Art Cylindrical grinding worms for spur gear roll grinding are, in their new state, statically and dynamically balanced in special balancing machines. In use, the grinding worm is subsequently regularly dressed, usually on a grinder, for dressing. After dressing, or at least after multiple dressings, the grinding worm must be newly balanced.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to simplify the balancing of such grinding worms.

[0004]

This problem is solved by the combination of the features of the claims.

The present invention is partly due to the unbalanced changes in dressing in the new condition of the worm teeth in order to avoid the risk of injury and damage during transport in the grinding worms used conventionally. It is based on the finding that a taper portion is provided at the front end portion. In this case, the entry and exit portions of the thread are shaved in the front face to remove the sharp-edged end.

These taper portions mean to reduce the mass of the worm teeth, and cause imbalance at both front end portions of the worm. The angular positions of the taper portions on both sides are offset from each other depending on the width and the lead of the grinding worm. Offset of these taper parts is 0 °
In the case of, static imbalance occurs, in the case of 180 °, dynamic imbalance occurs, and at other angles, not only static imbalance but also dynamic imbalance occurs.

In the new state, these unbalanced components are balanced with other unbalances in the grinding worm. However, when the grinding worm is subsequently dressed during use, these tapered portions are not post-processed, and therefore these tapered portions gradually disappear. This causes both imbalance vectors on both fronts of the worm to change in magnitude and direction, which requires rebalancing.

The method according to the invention as claimed in the claims eliminates these customary and conventional tapers at the thread entry and exit parts and thus requires rebalancing after dressing. It removes the primary factor.

The grinding worm is made of a cylindrical material.
These cylindrical grinding wheels are delivered in different widths in stages. In the case of conventional conventional grinding worms, the entire width of these materials is utilized for the worm threads.

The present invention is based on the supplementary finding that by reducing the grinding worm width to a specific dimension, the imbalance caused by the thread geometry can be eliminated in a targeted manner.

That is, the static imbalance caused by the thread geometry in the absence of a taper is zero when the grinding worm width is an integral multiple of the worm's lead, unlike a worm with a taper. know. On the other hand, the dynamic imbalance is minimized when the grinding worm width is an odd integer multiple of 1/2 of the lead.

The present invention, by contrast with conventional grinding worms, does not deliberately use the full blank width, but by selecting the grinding worm width to minimize the dynamic imbalance introduced by the thread geometry. It utilizes the above findings.

The result is a static imbalance caused by the geometry. The static imbalance changes resulting from dressing can be eliminated by balancing in one plane by a balancer inside the machine.

On the other hand, the dynamic imbalance caused by the geometry is minimal, so that even with dressing, the change in dynamic imbalance caused by this geometry is significantly smaller than in the case of conventional grinding worms. As a result of using the method according to the invention, the static imbalance must be corrected (retouched) after every dressing, but the correction interval is much longer than before. Static imbalance corrections can be quickly made while still attached to the grinder itself, thus substantially eliminating substantial downtime of the grinder. When rebalancing the dynamic balance, the grinding worm must be removed from the grinder and mounted on a special equilibrium testing machine, but in principle this rebalancing is not necessary in the case of the method according to the invention.

As a result, the rebalancing can be performed very quickly. Although the grinding worm according to the invention certainly has to be better protected than the conventional grinding worm for transport, this grinding worm can be used substantially more reasonably later in use.

Embodiments of the present invention will be described below with reference to the drawings.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENT The grinding worm shown in FIGS. 1 and 2 is made from a cylindrical grinding wheel blank of a corresponding diameter and a predetermined width a. First, on one side of the blank, the width of the blank is shortened in the outer region to the dimension b, so that for example the cylindrical hub 2 is left only in the inner region which is not subsequently used for grinding. Subsequently, the worm screw thread 3 is rolled or cut to form a single spiral worm tooth 4. The sharp edges 5 of the outlet part 6 on both front faces 7, 8 are left unmachined as usual and are slightly rounded or rounded to prevent injury in either case. The width b is chosen such that the outlet portions 6 on both front faces 7, 8 are offset by 180 ° from each other. The width b is determined by the following formula b≈mπ (GZ + 0.5) ≦ a, where m is the module (mm) and GZ is an integer.

In FIG. 3, the width a of the grinding wheel material is 104 mm.
FIG. 7 is a diagram for quickly obtaining the optimum width b in the case of

FIG. 2 shows both unbalance vectors Uv and Uh at the front front face 7 or rear front face 8 of the grinding worm 1 for an arbitrarily selected width b of the grinding worm 1. As an example, we will calculate both of these imbalance vectors when the worm tooth 4 has a trapezoidal profile. The results of these calculations are shown in FIG. In this case, FIG. 4A shows that both unbalance vectors U
Static imbalance Ustat formed by v and Uh
4 (b) shows the formed dynamic imbalance Udyn,
Further, FIG. 4 (c) shows both unbalance vectors Uv and U.
The angle ΔPhi between h is shown as a function of the number of threads of the grinding worm 1, respectively.

As is clear from the figure, the static imbalance Ustat is exactly 0 when the number of threads is an integer. Static unbalance Ustat when the number of threads is an odd integer multiple of 1/2
Is the maximum. On the other hand, when the number of threads is an odd integer multiple of 1/2, the dynamic imbalance Udyn becomes the minimum. In the case of very small integers that have no meaning in practice, the optimum value will be small, but small.

[Brief description of drawings]

FIG. 1 is a side view of a grinding worm.

FIG. 2 is a front view of one half of the grinding worm shown in FIG.

FIG. 3 is a diagram for obtaining an optimum grinding worm width.

4 is a diagram showing the unbalance and the angle between both unbalance vectors as a function of the number of threads, FIG.
4A shows the static unbalance Ustat, FIG. 4B shows the dynamic unbalance Udyn, and FIG. 4C shows the angle ΔPhi between both unbalance vectors.

[Explanation of symbols]

 1 grinding worm 2 hub 3 screw thread 4 worm tooth 7,8 front face b gap between both front faces GZ integer m module t lead

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Rolf Jankowski Germany Day – 7880 Bad Zeckingen Trotker-Strasse 2

Claims (3)

[Claims] 1. A cylindrical grinding worm for roll grinding of spur gears, comprising worm teeth (4) terminating without tapering on the radial front faces (7, 8) on both sides, between both front faces (7, 8). The distance (b) between the worm leads (t) over at least a portion of the diameter of the grinding worm.
Cylindrical grinding worm for roll grinding of spur gears, which is approximately an odd integer multiple of half of. 2. The distance (b) between the two front faces (7, 8) is calculated by the following formula: b≈mπ (GZ + 0.5), where m is a module (mm) and GZ is an integer. Item 1. The grinding worm according to item 1. 3. The grinding worm according to claim 1, wherein the hub (2) is integrally formed on the front surface of at least one side of the grinding worm (1).