Steel steelmaking operation of no. 3 converter maintenance cleaning thin oil terminal screen, it found that a large number of metal filaments and sheet metal, open the second box observation hole and take out 1 a box, check 4 a box output gear and the second box big gear tooth surface, large gear tooth surface gear tooth type found serious agglutination phenomenon, gear has been here all the steps of the 0.5 1.0 mm. 

 

By tilting device of converter drive system torque monitoring data, the lubrication condition, operating status, technical data and gear tooth reducer assembly accuracy is analyzed, ruled out factors such as operation, overload, lubrication and assembly, the big gear tooth surface hardness is low is a major cause of tooth root joints of agglutination phenomenon. 

The torsion bar suspension balance type and 4 point meshing the tilting of flexible drive device is by far the most common, the most mature technology of converter tilting mechanism. For low speed and overloading reducer, usually adopt bevel gear transmission design. Steel steelmaking operation department 5 converter tilting device of a reducer adopts helical gear transmission. For secondary reducer, 1, no. 2 converter tilting adopt bevel gear transmission, can improve the overlap ratio, stable transmission, but there is a certain axial force; 3-5 of converter tilting used straight tooth transmission, no axial force. 

In terms of gear material selection, bearing high and huge impact for gear transmission, general selection of carburizing and quenching steel. Steel steelmaking operation of converter tilting device of a reducer all pinion gear and secondary reducer adopts carburizing and quenching treatment, the heart of the gear department has good toughness, surface residual compressive stress after hardening, have stronger resistance to pitting corrosion and wear resistance properties. 3-5 large gear is made of high quality quenched and tempered steel converter tilting, suitable for low speed gear transmission, low manufacturing cost, has good strength and toughness, tooth surface hardness is low, ease of gears running-in, but cannot give full play to the carrying capacity of the materials; 1, no. 2 converter tilting big gear is made of high quality quenched and tempered steel surface hardening treatment, the manufacturing cost is high, the heart of the gear department has good toughness, surface residual compressive stress after hardening, have stronger resistance to pitting corrosion and wear resistance, improve the bearing capacity. 

In normal work tilting torque, rated working tilting moment and accident cases, the tilting torque and according to the motor rated power and speed, the school is tilting device transmission system safety factor of the contact strength and bending strength safety factor. In the case of not to make any correction, calculation and check of tilting four transmission, data can be seen from the school, working in normal circumstances, in accordance with the work of tilting torque, rotating speed of the motor rated power and rated school calculate tilting device transmission system, the contact strength safety factor and the bending strength and safety coefficients. Work in accident cases, the tilting torque tilting device transmission system meets the requirements, the bending strength safety coefficient of contact strength safety coefficient is low, but on the appropriate revisions can also meet the requirements. In general, all tilting device of converter design school is qualified. 

To be sure, adopt bevel gear transmission and hard tooth surface contact with four levels of transmission, whether it is in working status, the rated condition, or the accident situation, the contact strength safety coefficient and safety factor of the bending strength meet the requirements, and higher than in the straight tooth, the safety factor of the hard tooth face four transmission. In low speed, the overloading of converter tilting transmission, using hard tooth surface helical gear transmission shall be the preferred solution. 

Actual usage of converter tilting reducer 

And the analysis of on-site testing 

For further analysis of converter tilting secondary cases of big gear tooth surface agglutination, the cause of the converter steelmaking process, including the steel before startup, tilting to the position of steel, steel front brake midpoint, tapping, tapping process after the start and process, such as rotary reset selected part of the actual operation data. Filter data covering each tapping process, as far as possible in the process of motor power near and near the big run data as the representative, based on the operating data of a screen, and in the process of actual operation of converter motor voltage, current and rotating speed respectively calculate the motor power of the converter in the actual runtime and tilting device torque transmission system of the practical work, and in order to calculate tilting device transmission system safety factor of the contact strength and bending strength safety factor. Known from the analysis of the practical and the school is run data, the converter in the steel, slag and the normal tilting process such as the scrap steel, motor power and the practical work of moment in the normal range, converter tilting device transmission system safety factor of the contact strength and bending strength safety factor were higher, driving school is unqualified, converter tilting device transmission system working properly. 

1, 2, 18 in the tapping process of converter in practical running status after only five school running state is safety coefficient is low, the motor power, the actual work properly beyond the rated torque, tilting device transmission system still school is qualified. But 3-5 to 20 in the tapping process of converter in practical working condition only four running state schools qualified safety coefficient, low safety factor of running status of the remaining 16. 1, no. 2 converter tilting device, therefore, the bearing capacity of strong, more than 3-5, converter tilting device can meet the demand of actual working condition. 

Big bond cause analysis of the gear tooth surface 

By comparing the design of converter tilting device and the school is use case analysis, the actual working condition of the school is analyzed and the actual test results of numerical analysis, major cause of gear tooth surface agglutination can be grouped into the following four aspects: 

1) relative to the straight tooth, the hard tooth face drive, helical, hard tooth surface drive bearing capacity is strong, high contact strength safety factor and the bending strength safety factor, more can satisfy the low speed and overloading of actual working condition of demand of converter tilting device. 

2) titled actual manufacturing precision of the gear transmission system, including tooth accuracy and precision of the heat treatment process meet performance, for the tilting device carrying capacity and the ability to meet the demand of actual working condition. 

3) the actual working conditions of quick start, rapid braking and dynamic and rapid changes in the rotational speed of the motor power and will form a larger working torque, impact of tilting device transmission system at the same time, the carrying capacity for the tilting device put forward higher requirements. 

4) based on the tilting of the hard tooth face gear drive system, combined with the actual conditions of quick start, fast hard tooth surface of brake and point of impact, caused the damage of the gear surface, form the metal filaments and sheet metal. 

According to the analysis of the tilting device of converter drive system, in as much as possible not sharp quick start and rapid braking and minimize the dynamic case, such as to improve the big gear no.3 converter tilting. Based on the current situation of converter tilting, the improved scheme still USES the straight tooth gear, its basic parameters are almost the same with the original design, form a complete set of spare parts and the tilting device and used interchangeably. 

Plan 1 still use of modified treatment weeken the hard tooth face, by changing the quenching and tempering temperature and time, improve the comprehensive mechanics performance of the big gear, to increase the large gear tooth surface hardness to HB320-340. Big gear tooth surface hardness is improved, in the case of rated torque, big gear contact strength safety factor and obviously improve the bending strength safety factor. Using this scheme, the gear blank forging and conditioning treatment after rough machining, need a big gear overall welding and annealing, after processing and roll teeth directly, relatively short manufacture cycle, cost is relatively low. 

Scheme 2 USES the hard tooth face, first of all to the big gear overall conditioning treatment to the hardness HB320, made the heart of the gear has good toughness, and then to quench hardening on the surface treatment, make tooth surface residual compressive stress, improve the tooth face hardness and pitting corrosion resistance and wear resistance properties. Improve the tooth surface hardness, after working in the rated torque, big gear contact strength safety coefficient and bending strength safety factor than in the hard tooth face have improved. Using this scheme, first of all need to gear blank forging and tempering treatment, rough machining of big gear after the overall welding and annealing, and then to the whole of big gear machining and roll teeth, and then to surface hardening treatment, in order to improve the tooth surface hardness. Because of the big gear diameter is larger, so late to shave tooth processing. The scheme of manufacturing cycle is relatively long, the cost is relatively high, but the big gear contact strength safety factor and the bending strength safety coefficient is higher, the heart of better comprehensive mechanical properties, tooth surface hardness is relative taller, more suitable for low speed, overload, and have a certain impact of converter tilting device. 

Of hard tooth surface gear and hard tooth surface gear basic parameters of the comparison results show that the hard tooth face gear and hard tooth surface gear can meet the requirements of production process. Among them, the hard tooth face gear processing cycle is short, the cost is low, the general use similar equipment; Hard tooth surface gear mechanical properties compared with the hard tooth face gear has no obvious advantage, and the processing cycle is long, the cost is high, the less similar equipment application. 3 new big ring gear wheel of converter spare parts manufacturing process adopted in the hard gear tooth surface. 

To sum up, the use of new technology of manufacturing of hard tooth surface of secondary cases of big gear in no.3 converter tilting device transmission system using three years later, tooth contact is good, the normal operation condition, change the quenching and tempering temperature and time, can obviously improve the comprehensive mechanics performance of the big gear, prolong its service life. Should pay attention to improve the machining precision of the tooth at the same time, in order to satisfy the actual working condition of the converter tilting device at low speed and heavy.