UA66399C2 - Method for repair of gearings - Google Patents

Abstract

Invention relates to the methods for restoration and repairing the articles and it can be used for repairing predominantly large-module gearings, in particular, gearings of ore crushing and coal pulverizers and rolling mills, gear rings and gears of mechanisms of turning of excavators and excavatingcomplexes. The method of repairing the gearings includes machining of cog-wheel and gear. In this case in the gear from each involute tooth is made a concave tooth of round-screw point gearing, and gear is made with convex teeth of round-screw point gearing from the new billet combinable with the profile of the teeth of gear or from deposited existing gear. Invention ensures simplification in the technology of repair of gearings, increase of their service life, reduction in man-hours and power intensity of their repair.

Description

Description of the invention

The invention relates to the restoration and repair of products and can be used to repair mainly 2 large-module gears, in particular gears of ore-grinding and coal-grinding mills and rolling mills, toothed crowns and gears of turning mechanisms of excavators and earthmoving complexes.

There is a known method of restoring gear wheels (see USSR copyright certificate Mo1682109 IPC 5823RB/00 dated 09.11.89, published on 10.07.91), which includes mechanical processing of gear wheels. The method also includes making 70 through holes in the teeth of the gear wheel, the subsequent sequential placement of each tooth of the gear wheel in a closed volume, equidistant profile of the tooth, inserting the electrode into the hole of the tooth to the base of the closed volume, melting the electrode and the tooth by electric arc melting with molten filling closed volume with metal and solidification of the metal. After welding all the teeth of the gear wheel, the teeth are machined. Gear teeth are restored in the same way. 19 This method allows you to restore the teeth of only spur gears with a relatively small width of the gear wheel and gear, that is, with a relatively small length of the teeth, because drilling through holes in the teeth with a length of 300-800 mm is time-consuming and requires the use of special drills for deep drilling.

The disadvantage of this method is also that it does not allow to restore the teeth of helical and chevron wheels, since their teeth are not straight.

The disadvantage of this method is that even when restoring spur gears with a relatively short length of teeth, but which have 200-300 teeth, this method is time-consuming and energy-intensive.

A method of restoring large-module gear wheels is also known (see the author's certificate of the USSR

Mo1691043 IPC 5823RB/0О dated 10/23/89, published 11/15/91), which includes mechanical processing of gears with 29 wheels. The method also includes making along the teeth along the axis of their symmetry grooves corresponding to the height of the teeth, subsequent heating of the crowns of the gear wheels to a temperature of 1000-10507C and distributing the teeth in the stamp to the required thickness, placing sintered powder porous inserts in the grooves of the teeth, reheating the crowns to a temperature of 1000-1050" and pressing of the teeth in a stamp and subsequent mechanical processing of the teeth. If necessary, after mechanical processing of the teeth, their chemical and thermal processing is performed. o

This method of restoring gear wheels in comparison with the method of restoring gear wheels according to Ge"! the author's certificate of the USSR Mo1682109 allows to restore helical and chevron gears with any length of teeth, because they have an open longitudinal groove along the axis, which can be done by milling. Gee)

However, the disadvantage of this method is the high complexity of making longitudinal grooves in the teeth of 3o gear wheels if they have 200-300 teeth and a tooth length of 300-800mm. eh

The disadvantage of this method is also the fact that its implementation requires two heating of the crowns of gear wheels to a temperature of 1000-1050 and the need to use special stamps and appropriate press equipment for distributing the teeth and their subsequent pressing, which makes it energy-intensive. "

The disadvantage of this method is the need to use sintered powder porous inserts, which makes Z 50 this method expensive. c To determine the level of technology, patent information from class 7823Rb6/00 and scientific and technical information were studied

From" for the period 1986-2000. including those related to the methods of restoration and repair of gear wheels.

The invention is based on the task of creating a fundamentally different method of repairing gears, which is not based on restoring the involute profile of the teeth to their original size and allows to significantly increase the durability of gears and reduce the labor and energy consumption of their repair. b In order to achieve this technical result when performing a method of repairing gears, which

Gee! is claimed, which includes the mechanical processing of the teeth of the gear wheel and the gear, in the gear wheel, a concave tooth of helical point engagement is made from each involute tooth, and the gear is made with convex teeth of helical point engagement, which are connected to the profile of the teeth of the gear wheel, from (Те) 20 of a new workpiece or from welded existing gear.

There is a cause-and-effect relationship between the distinguishing features of the claimed invention and the technical result achieved. The peculiarity of the claimed method of gear repair is that when it is carried out in the gear wheel, the worn involute teeth are not restored to their original dimensions with the same profile, but new ones, equal in strength to the original involute teeth or 29 prevailing ones, are cut from these teeth, taking into account their wear their strength, concave teeth of helical point engagement. At the same time, the gear is performed

ГФ) with convex teeth of a helical point engagement that are connected to the profile of the teeth of the gear wheel from a new workpiece or from a welded-on existing gear. This significantly simplifies the gear repair technology, and reduces the labor and energy consumption of their repair. To achieve this technical result, the following new set of distinguishing features is necessary: 60 executions from each involute tooth of a gear wheel of a concave tooth of a helical point engagement; production of a gear with convex teeth of a helical point engagement, which are connected to the profile of the teeth of the gear wheel, from a new workpiece or from a welded-on existing gear.

The exclusion of at least one feature from the specified new set of distinctive features does not ensure the achievement of the technical result: a significant simplification of the gear repair technology, a reduction in the labor-intensiveness and energy-intensiveness of their repair.

Therefore, the specified distinguishing features are essential, since each of them, taken separately, is necessary, and all of them, taken together, are sufficient to distinguish this object of the invention from all other objects of the same purpose and to obtain a technical result.

The claimed invention is not part of the prior art, so it is novel.

The claimed invention has an inventive level, because its implementation with the set of essential features specified in the claims, for a specialist, clearly does not follow from the existing state of the art.

The claimed invention is industrially applicable. A methodology was developed for calculating the profile of concave teeth of 7/0 Helical point engagement, which are cut in the gear wheel from worn involute teeth, as well as the profile of the convex teeth of the circular helical point engagement, which are connected to the profile of the gear teeth, for the gear, which is made from a new workpiece or from a welded existing gear . The appropriate technology for gear repair has been developed.

In the toothed wheel and in the gear of the gear that is being repaired, any /5 Round screw point engagement, including the Novikov engagement, can be made.

Figure 1 shows a diagram of the method of gear repair when repairing a gear wheel of a non-reversible gear with one-sided tooth wear; Fig. 2 is a diagram of the implementation of the repair method for the repair of the gear wheel of the reverse transmission with bilateral wear of the teeth; in fig. - tooth profile of a gear wheel with concave teeth of a helical point engagement after repair.

The drawing shows: 1 - profile of involute gear teeth; 2 - the profile of the concave teeth of the helical point engagement of the gear wheel; C - worn layer of involute teeth.

The method of repairing gears is carried out with the following sequence of operations: measure the teeth of the gear wheel to determine the degree of wear of the teeth; based on the results of measuring the teeth of the gear wheel, the geometry of the concave teeth of the circular screw point engagement is calculated for it, which should ensure that the strength of these teeth is not less than the strength of the new involute teeth; i) calculate the geometry of the convex teeth of the helical point engagement for the gear with the condition of their combination with the profile of the teeth of the gear wheel; if the involute teeth of the gear wheel have high hardness, then to improve their machinability Ge! zo gear wheel is annealed; if the gear is made from a new blank when repairing the gear, this blank is made; If, during the repair of the gear, the existing worn gear is used, metal surfacing is made along its rim to the required dimensions; make a gear wheel and a gear with helical point engagement teeth; ise) if necessary, they perform chemical and thermal treatment of the teeth of the gear wheel and gear. co

Below is an example of the method of gear repair when repairing an open helical involute non-reversible drive gear of an ore grinding mill.

Example.

Output Data: "- engagement module: та-20mm s number of gear teeth: 2-43:з" angle of inclination of the tooth line: р-5'3802" dividing diameter of the wheel: а-4899.17mm diameter of the tops of the teeth of the gear wheel: yes- 4939.17mm (o) the diameter of the cavities of the teeth of the gear wheel: ag4849.17mm, the width of the gear wheel: b-800mm, the transmission ratio: i-5.67442 o, the material of the wheel: steel 4OHL DST 977-75

Ge) 20 hardness of the rim and gear teeth: nVv-174-220 degree of accuracy: 9-X DST 1643-81 iChe)

We calculate the endurance of involute teeth during bending according to /1, p. 110-116/,

In open gears, the factor that determines their durability is the endurance of the teeth when bending when worn to the point of sharpening the tips of the teeth. Since in such gears the gears are made of cast steels, which have lower mechanical properties compared to gear materials made of rolled steel or forgings of structural and alloy steels, below is only a calculation of the bending strength of the concave teeth of a helical point engagement for the gear wheel as the weaker link of the gear transmission. 60 We calculate the permissible torque that can be transmitted by a gear wheel with new involute teeth, using the formula /1, p. 116/; (g 1- Eva Te sk vh vet "N.mm cheh vh de: sgr - allowable stress when calculating the endurance of the teeth during bending, MPa; is equal to /1, p. 115, 62 table. 7.11/:

cER-135 MPa;

b - gear wheel width, mm; a - dividing diameter of the gear wheel, mm; tp - engagement module, mm;

Me- tooth shape coefficient;

Uv - tooth inclination coefficient;

Ke is the bending load factor.

The tooth shape factor is chosen depending on the equivalent number of teeth of the gear wheel, equal to 70.1, p. 113/; in EE - n - 347 soye? in (sovbv33ver

Hence: Me-3.75 /1, p. 113, tab. 7.10/.

The tooth inclination coefficient is equal to /1, p. 116/:

UrV-1-r/1407-1-5.63397/1407-0.96

The bending load coefficient is equal to /1, p. 111/:

Ke-KeeOKeEVOKeU where: Ker: - coefficient that takes into account the load distribution between the teeth;

Kev - a coefficient that takes into account the uneven distribution of the load along the length of the tooth;

Kehu - coefficient of dynamism when calculating teeth for bending.

Keo-1 /1, p. 112/; KeV-1 /1, p. 112, tab. 7.77;

Keh-ZKnu-2 /p. 113, tab. 7.8/, where Kuru is the coefficient of dynamism when calculating teeth for contact strength; is equal to /1, p. 113, tab. 7.8/:

Then: Keuch1,1-2-1,3. with

Ke-1x1x1.3-1.3. heh)

Thus: 135 x 800 x 41 x 20

Pe» uatvkhovvit - 1130600000 N.mm-1130600 N.m

We make a geometric calculation of the concave teeth of the helical point engagement, performed in the Ф 3о gear wheel instead of the involute teeth. When calculating, we proceed from the fact that in the gear wheel F) the teeth of the Novikov cross-pole engagement with one line of engagement are performed. We calculate according to /2, p. 27-32. at

The number of teeth and the angle of inclination of the tooth line remain the same as in a gear wheel with involute teeth, (Ce) and equal: 39 two; d-5.6339".

We accept the engagement module: tu-20mm.

The dividing diameter of the gear wheel is /2, p. 317; shal 20 x 244 - 4899 17mm « 20 sor o so55,63399 -v s The pitch diameter of a gear wheel with concave teeth of a helical point engagement is equal to . to the pitch diameter of a gear wheel with involute teeth, so the gear ratio does not "" change.

The diameter of the tops of the teeth of a gear wheel with concave teeth of a helical point engagement is: (22) i - 5-02 - 489917 -0.2x 20 - 489517 MM

Ge") The height of the concave teeth of the helical point engagement is /2, p. 29/: p-1.3t0-1.3x20-26bmm. o The diameter of the depressions of the concave teeth of the helical point engagement is /2, p. 327: с 0720 ф-,-2- 489517 - 2x 26 - 4843 17MM (Че) The amount of additional cutting into the edge of the gear wheel when cutting the concave teeth of the helical point engagement on it is equal to: в- ау - 9, - 18497 - 484317 zm 2 2 o, which is 0.15tu.

The coordinates of the center of curvature of the concave surface of the gear teeth are equal to /2, p. 29/; ko Chi0.552339t 4-0.5523391120-11.047mm;

Me0.075ty-0.075020-1.5mm. 60 The radius of curvature of the concave surface of the gear teeth is /2, p. 29/: mouths -1.55020-31mm.

We calculate the endurance during bending of the concave teeth of a helical point engagement, using /2, p. 25; with. 57-80/.

The permissible torque is /2, p. 78/: b5

ItI- Prhdh eh Eh SE

KdhKikh shk de: tu-20mm - engagement module; 727-244 - the number of gear teeth; is - coefficient of axial overlap;

Me- tooth shape factor; svgr-135 MPa - allowable stress when calculating the endurance of the teeth during bending /1, p. 115, tab. 7.11/;

Kd - coefficient of dynamism;

Ku - a coefficient that takes into account the influence of the angle of inclination of the teeth on the breaking strength; shk 7" marginal coefficient.

The coefficients are equal: врх зипр /2, s. 25 - 800 x vipbBZ Bo - 2125; LPH T ZY YH 20

Me1.6 /2 s. 75, fig. 26/; Kd-1,2 /2, p. 130, tab. 3/;

Kd-0.13 /2, p. 57, fig. 20/; uk-1.85 /2 s. 57, fig. 20/

So:

Z y pkr- I insects m xx y, x1Vx13 o Mv43800000 Nmme 1643600 NM pah 01 Zx 185

The concave teeth of the helical point engagement in the repaired gear wheel provide, in comparison with the involute teeth, the transmission of a greater torque: (ITkI-1643600НОm2 | Te1-1130600НОm, or: (ТКиI: (Те!й-1643600:1130600-1,454, с 29 i.e. |Tki more (Ti in 1.454 times. Ge)

From the calculation of the geometric dimensions of the concave teeth of the helical point engagement, performed in the gear wheel instead of worn involute teeth, it follows that such teeth are feasible even with involute teeth worn to the point of sharpening, because the diameter of the tops of these teeth is smaller than the diameter of the pitch circle, while the diameter of the pitch circle of the gear wheel remains unchanged, which means that Ф the gear ratio of the gear remains unchanged. Gee)

In addition, since the concave teeth of the helical point engagement have a height that does not exceed 1.1-1.3 of the value of the engagement module, the amount of cutting into the edge of the gear wheel in the considered example of Shk implementation of the method is Zmm, i.e. 0.15 of the engagement module. Given the fact that for cast gears (Ce), the thickness of the rim is equal to 3-4 engagement modules, this notch does not affect the strength of the teeth and the entire toothed 32 wheel as a whole. ish

From a comparative analysis of the calculation of new involute teeth and concave helical point engagement teeth, manufactured in the gear wheel instead of worn involute teeth, it follows that the latter exceed the strength of the former. "

Due to the fact that during the implementation of the gear repair method, which includes mechanical processing of the teeth Z 70 of the gear wheel and the gear, in the gear wheel, a concave tooth with a helical point engagement is made from each involute tooth, and the gear is made with convex teeth that match the profile of the gear teeth "from the wheel helical point engagement teeth from a new workpiece or from a welded existing gear, the durability of gears is significantly increased and the labor and energy-intensiveness of their repair is reduced, because this method does not use complex and energy-consuming equipment. 75 At the same time, the implementation of concave helical point teeth almost no engagement

F reduces the strength of the gear rim, because these teeth have a height equal to 1.1-1.3 of the engagement module, and when

Ge"), their cutting reduces the thickness of the rim by an insignificant amount.

The proposed method of repairing gears is especially effective when repairing large-module and massive large-sized gears. (Se) 50 Thus, the claimed method of repairing gears ensures the achievement of a technical result, which consists in increasing the durability of gears and reducing the labor and energy consumption of their repair.

Therefore, the method of gear repair, which is claimed as an invention, is new, has an inventive level, is industrially suitable and ensures the achievement of a technical result. Thus, it meets the conditions of 59 patentability and can be granted legal protection.

GF) Sources of information: t 1. Calculation of parts and components of metallurgical machines: Reference book, Svystunov E.A., Chichenev N.A., M:

Metallurgy, 1985. 2. Gear transmission with engagement Novikova, Pavlenko A.V., Fedyakin R.V., Chesnokov V.A., Kyiv: Technika,

Claims (1)

60 41978. The formula of the invention is the Method of repairing gears, which includes mechanical processing of the gear wheel and gear, which differs in that in the gear wheel a concave helical point engagement tooth is made from each involute tooth, and the gear is made with convex helical point engagement teeth matching the profile of the gear teeth, from a new workpiece or from a welded existing gear. 70 s with o Ge) Ge) so (se) (Se) - a Ge) Ge) (95) (se) (Che) ko 6o 65