Simple manufacturing method of the hottest large m

Simple manufacturing method of large modulus bevel gear

1 introduction

in port handling equipment, imported equipment accounts for a large proportion. Imported equipment has a series of advantages, such as large bearing capacity, simple operation, stable operation, durability and so on, but the accessories of imported equipment are expensive, and the supply period is long. In addition, foreign machinery and equipment are upgraded too quickly, which has caused great difficulties for domestic maintenance of imported equipment to purchase accessories. For example, a pair of British large modulus bevel gears in the traveling transmission system of several Sumitomo UC-25 tire cranes made in Japan in our port are damaged. The purchase of foreign accessories is not only expensive, but also the supply cycle is too long, which seriously affects the maintenance of the equipment and the timely production and use. General domestic machinery manufacturers do not have large modulus bevel gear planer, which cannot be processed; Although some heavy machinery factories have large modulus bevel gear planers, the supply time is too long and the asking price is too high. Therefore, according to the generating principle of designing and manufacturing bevel gears and the calculation of geometric parameters of transmission, we have mapped the big end of the damaged large modulus bevel gears and calculated the geometric parameters of each part of the large modulus bevel gears. With these parameters, the wood mold is made first, then the metal aluminum model is cast, and the metal aluminum model is used for precision casting. After machining the internal spline hole, install it on the spiral gear milling machine for pairing grinding to correct the tooth shape. Through the actual measurement, the technical performance of imported accessories is completely achieved, and the problem of supply of large modulus bevel gear accessories during maintenance is solved in time

now we will introduce our practice for the reference of colleagues

2 measurement and calculation of bevel gear

because the bevel gear disassembled from the equipment has been damaged, but the big end of the gear has not been worn. The tooth shape has been carefully developed, and the external contour of the independently designed grinding disc extruder is complete, which brings convenience to the actual mapping and calculation

2.1 measured data of conical teeth

number of teeth: gear z1=17, gear z2=21; Axis intersection angle 90 °; Addendum circle diameter: Φ ｚ1=269.30mm， Φ Z2=312mm  top cone angle  Φ ｅ1=44°30′， Φ E2=56 ° 30 ', tooth height h =33.4mm  tooth shape angle α= 20 °  tooth width b=76mm

2.2 calculation data of parameters

modulus m=14.51 tooth height h =33.38mm

number of crown teeth: zk=27.02 outer cone distance: le=196.03mm

pitch cone angle: Φ 1=38°59′ Φ 2=51 ° 01 ′

addendum angle: θ = 4 ° 14 'tooth root angle: γ= 5 ° 30 '

top cone angle: Φ ｅ1=44°29′ Φ E2=56 ° 31 '

root cone angle: Φ ｉ1=33°29′ Φ I2=45 ° 31 ′

indexing circle diameter: d1=246.67mm d2=304.71mm

equivalent number of teeth: zd1=21.87 zd2=33.34

indexing circle chord tooth thickness (big end): sxn1=sxn2=22.77mm

2.3 measured data of involute internal spline part

(1) Involute spline data of bevel gear with tooth number z=17

outer diameter of hole D =88.90mm tooth number z=20

inner diameter of hole D =81.17mm rod span m=74.024mm

diameter of measuring rod 7.315mm base knot ti=11.50mm

(2) Involute spline data of bevel gear with tooth number z=21

outer diameter of hole D =105.86mm inner diameter of hole D =98.11mm

tooth number z=24 span bar distance m=91.003mm

diameter of measuring rod 7.315mm, base knot ti=11.50mm

(3) modulus and pressure angle

Convert according to British data  modulus is m=4.23, pressure angle is α= 30 °, base section ti=11.50mm

3 manufacturing process

3.1 making model

according to the geometric parameters of the large modulus bevel gear measured and calculated, it is first made into a wood shape, and then cast into a metal aluminum model, and the aluminum model is necessary to be trimmed

3.2 precision casting

in order to ensure the precision of casting, resin sand is used as molding sand, and zg40cr is used as bevel gear material for melting casting

3.3 select the matching cast bevel gear

after casting the bevel gear, test it, select the bevel gear with no defects and good quality, and pair it

3.4 machining the internal spline hole and spline of bevel gear

when machining the internal spline hole of bevel gear, use the hub of large and small bevel gears Φ 132、 Φ Align the outer diameter of bevel gear based on 110 Φ 312、 Φ 269. After alignment, process to ensure the outer diameter of the bevel gear Φ 312、 Φ 269 is concentric with the inner spline hole

benchmark: select bevel gear spline hole and hub end face. Process splines on broaching machine, pushing machine or gear shaper

for the machining of British involute spline holes, a non-standard taper shank gear shaper cutter is customized to insert the spline holes, which improves the machining accuracy and production efficiency

3.5 paired grinding correction tooth profile

a selected pair of bevel gears are installed on the spiral bevel gear milling machine (a simple device can also be designed, on the lathe or milling machine) based on the spline hole to carry out reverse rotation paired grinding correction tooth profile. When grinding, it is necessary to inject abrasive between the meshing teeth

3.6 heat treatment

in order to improve the strength of gears and eliminate casting stress, heat treatment is carried out after preliminary grinding. Overall quenching and tempering of pinion, hb229~269, surface quenching of tooth surface, hrc55~60, hardening layer depth of 0.8~1.5mm. Overall quenching and tempering of large gears, hb229~21. Operators of this equipment must receive corresponding training 69, tooth surface quenching, hrc50~55

during heat treatment, care should be taken to protect the spline hole and minimize the deformation of the hole and spline. Carry out final pairing grinding after heat treatment

3.7 shot peening

in order to reduce the roughness of tooth profile and spline surface and enhance wear resistance, shot peening can be carried out after quenching

4 Conclusion

in the past five years, we have used this simple manufacturing method to manufacture a total of 8 sets of large modulus bevel gears, which have been used on Sumitomo UC-25 tire crane in Japan. So far, there have been no problems. Practice has proved that the advantages of this simple process are: the process is simple, easy to manufacture, the cost is only 2/5 of the cost of imported accessories, 4200 yuan per set, the production cycle is short, and the supply is timely, which solves the old and difficult problem of urgently needed accessories in maintenance. If the elongation of material exceeds 1000%, you can choose 1000 or 1200mm to obtain better technical and economic benefits

mailing address: Tianjin Port Material Supply Co., Ltd. (300456) (end), Tanggu District, Tianjin