Effect of Mandrel Exchange on the Precision Forging of Spur Gear

2011 ◽  
Vol 295-297 ◽  
pp. 1635-1638
Author(s):  
Cheng Yang ◽  
Sheng Dun Zhao ◽  
Jian Jun Zhang

In order to reduce the spur gear precision forging load and prevent load to rise sharply in final forging, on the basis of analysis the distribution of contact pressure of cylinder upsetting, mandrel exchange technology is put forward. As a result, the material always has free space to flow. The tool-set and experiment scheme are designed, finally, the scheme is further validated by Deform-3D, and the results show that the validity of mandrel exchange technology to reduce the load in gears precision forging.

2011 ◽  
Vol 295-297 ◽  
pp. 1631-1634
Author(s):  
Cheng Yang ◽  
Sheng Dun Zhao

According to the analysis of friction distribution on radial direction in the precision forging spur gear, the reason that the tooth corner was difficult to fill is revealed. Changing the motion mode of the floating die will change the friction condition between billet and floating die, as well as the filling situation of tooth corner. Finally, the scheme was further validated by DEFORM-3D, and the results show that the validity of floating die to tooth corner filling.


2009 ◽  
Vol 628-629 ◽  
pp. 535-540 ◽  
Author(s):  
Wei Wei Wang ◽  
Jian Li Song ◽  
Fei Han ◽  
Shou Jing Luo

Numerical simulation and test forming of the isothermal precision forging of an impeller was carried out. The forming processes were simulated with DEFORM-3D to obtain the forming characteristics and metal flow pattern. It indicated that the impeller can be forged by the method of isothermal-forging, and the deforming process can be divided into 3 stages. The forming of blades was depended on the extrusion of materials. During the forming, uneven deformation was existed in the billet, especially in the field of the blade root. The forging load was increased rapidly during the later stage of the forming process, and the maximum forging load was about 2961kN. According to the simulations, the die structure and the billet dimension were determined, the forging die was designed and manufactured, and the precision forgings of the impeller were produced successfully. Both of the simulation and the test forming indicated that the impeller forging could be performed with the assembled structure die and the isothermal extruding forming style satisfactorily. The ideal parameters to produce the precision forgings of the impeller are: a forging temperature of 450°C and a punch speed of 1mm/s. Under these conditions, the forgings of the impeller can be produced with full blades, smooth outer surface and good flow line, which can meet the requirements of the precision forging of impellers.


Author(s):  
Masashi Yamanaka ◽  
Shinji Miwa ◽  
Katsumi Inoue ◽  
Yoshiki Kawasaki

This paper deals with the evaluation of influence of the manufacturing methods precision forging and conventional hobbing on the bending fatigue strength of carburized gears. The forging has advantages in productivity and strength. The forged gear has a continuous directed fiber flow which runs along the gear profile. To clarify the effect of strength enhancement, a bending fatigue test is performed for the forged and the hobbed gears. The material of test gears is SCr420H in the JIS and all gears are carburized. The electrohydraulic servo-controlled fatigue tester is used in the constant stress-amplitude fatigue test. The strength is expressed by the fillet stress level, which is calculated by FEM. The obtained strengths of forged and hobbed gear are 1613 MPa and 1490 MPa, respectively. The strength of forged gear is increased 8% in comparison with that of the hobbed gear. The surface hardness is higher and the surface roughness is smaller in the forged gear, however, the residual stress is approximately same. The effect of improvement of the roughness by forging on the strength is small in 1%, and the main reason of the improvement of fatigue strength is considered as the continuous fiber flow.


Author(s):  
Hiroshi Mukoyama ◽  
Shigeyuki Shimachi ◽  
Yoshihide Hakozaki

Abstract Recent demands for gear couplings are to reduce the backlash and to increase the shaft angle limit. On coping with these demands, the tooth contact pressure is recognized as the trade-off problem. In the traditional estimation of tooth contact pressure, the deflection of tooth is calculated by using the formula for spur gear that has long contact bearing in the face width direction, although gear coupling has it in the tooth depth direction. And, the Hertz depression of the tooth surface is estimated as that of the infinite plane. Additionally, the traditional methods don’t consider about the edge contact on the tip or end of tooth. A successive approximation method is established to find the load distribution on the mating teeth surfaces. As for the effect of the edge contact on the tip or end of tooth, it is cleared that the contact pressure distribution deforms itself severely, but the maximum pressure is almost constant. The expressions estimating the maximum pressure and the displacement of tooth base are constructed for 6 parameters as follows; total load coefficient, relative curvature of teeth surfaces, tooth module, ratio of tooth height to face width, angle of tip contact and deviation of end contact.


2011 ◽  
Vol 189-193 ◽  
pp. 2642-2646 ◽  
Author(s):  
Qian Li ◽  
Yi Bian ◽  
Zhi Ping Zhong ◽  
Gui Hua Liu ◽  
Ying Chen

The cold forging process of large module spur gear with four modules and 59mm breadth is performed by means of numerical simulation method. Two processes to forming such spur gears were compared by the simulation method, one is with the closed-die performing and extrusion in the finish-forging, the other is with divided-flow method in the finish-forging. Especially, the divided-flow method is analyzed in detail. The necessary reference and basis to realize practical cold precision forging process of spur gear with large modulus is provided eventually.


2012 ◽  
Vol 472-475 ◽  
pp. 692-695
Author(s):  
Jian Hua Wang ◽  
Fu Xiao Chen

By analyzing the characteristics and forming technology of hypoid driving gear, it was suitable for adopting fully enclosed die forging principle to form the gear. Based on different forging methods, three kinds of blank shape and corresponding forming schemes were designed. The three dimensional models of blank and die were created by the UG software. The three forming schemes were simulated by the Deform-3D software. The simulation results of distribution of equivalent stress, distribution of equivalent strain and load-stroke curve were comparatively analyzed. Then the most reasonable scheme was chosen. At last, the rationality of numerical simulation can be further verified by the optimized scheme was proved by experiment.


2014 ◽  
Vol 622-623 ◽  
pp. 165-173 ◽  
Author(s):  
Nicholas J. Politis ◽  
Denis J. Politis ◽  
Catrin Mair Davies ◽  
Jian Guo Lin ◽  
Trevor A. Dean

A significant factor in the cost of industrial machinery for precision forging is the maximum load required to fully forge the final shape of components. Typically in a precision forging process, the required load increases greatly towards the end of the stroke. This study focuses on reducing the final sharp increase in load encountered in a typical closed die forging setup. A technique of reducing the peak load in the forging of gears is proposed, named the Peripheral Relief (PR) method. A gear forging tool set has been designed and manufactured. A number of experimental trials have been performed using model materials to investigate the force reduction technique. An efficient and simplified FE model has been developed to evaluate the effects of the PR method. The experimental load characteristics are compared to the simulated results. The method has been found, both numerically and experimentally, to significantly reduce the peak load encountered at the end of the forging stroke compared to current closed die forging techniques.


2007 ◽  
Vol 561-565 ◽  
pp. 831-834 ◽  
Author(s):  
Yu Li Liu ◽  
He Yang ◽  
Tao Gao

A blade with a damper platform, with excellent anti-vibration characteristic and high efficiency, has become one of the most important types of blades being developed in the aeronautical engines. During the precision forging process of this blade, the friction between dies and workpiece has important effects on metal flow, deformation defects, load and energy etc. So researching the effects of friction conditions on the forging process of blade with a damper platform has been a crucial problem urgent to be resolved. In this paper, the precision forging process of titanium alloy blade with a damper platform under different friction conditions has been simulated and analyzed based on the DEFORM-3D software platform. The obtained results reveal the influence laws of friction on temperature field and load-stroke curves, and provide a significant basis for determining technological parameters of the blade forging process.


2014 ◽  
Vol 1 (4) ◽  
pp. 456-462 ◽  
Author(s):  
Wangjun Cheng ◽  
Chengzhong Chi ◽  
Yongzhen Wang ◽  
Peng Lin ◽  
Wei Liang ◽  
...  

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