scholarly journals Wear load capacity of crossed helical gears with wheel made from sintered steel

2015 ◽  
Vol 47 (2) ◽  
pp. 153-163 ◽  
Author(s):  
A. Miltenovic ◽  
V. Nikolic ◽  
M. Banic

Crossed helical gears have an important position in power transmission. Important advantages of the crossed helical gears are the small design, the realization of high ratios in one stage, and the low noise characteristics. The paper presents a theoretical and experimental research of mesh efficiency, tooth friction coefficient and wear for a wheel of crossed helical gears made of Fe1.5Cr0.2Mo sintered steel with sinter-hardening treatment and without additional treatment. The calculation method is also given for the determination of wear load capacity of the worm with a helical gear made of Fe1.5Cr0.2Mo sintered steel with sinter-hardening treatment. These results provide product developers with the first important clues for indicators for calculation of the worm with a helical gear.

2011 ◽  
Vol 43 (2) ◽  
pp. 205-214 ◽  
Author(s):  
A. Miltenovic ◽  
W. Predki

Sintered steel appears to be a very effective material for wheels in crossed helical gears. High demands are set on gears made from sintered steel regarding wear, fretting, tooth fracture and pitting load capacity. This report shows results of iron-based sintered material Fe1.5Cr0.2Mo in case of crossed helical gears concerning wear resistance and other damage types under different speed, torque and lubricants. As material variants, samples with additional treatment, such as pyrohydrolysis, case hardening, shot peening, sinter-hardening, and 2% copper addition are used.


2010 ◽  
Vol 42 (2) ◽  
pp. 183-191 ◽  
Author(s):  
W. Predki ◽  
A. Miltenovic

High demands are set on gears made from sintered steel regarding wear, fretting, tooth fracture and pitting load capacity. The hardening obtained after the sinter process will affect the microstructure of the sintered steel so that the wear load capacity can increase to higher values. This report shows the influence of different hardenings methods on crossed helical gears fabricated from Fe1.5Cr0.2Mo sintered steel and the changes induced on the microstructure, the surface and the core hardness and the wear load capacity. The research presented in this paper is aimed at finding the most appropriate additional treatment which leads to higher wear load capacity as compared to the wear of sintered steel gears without any additional treatment.


2013 ◽  
Vol 633 ◽  
pp. 197-208 ◽  
Author(s):  
Aleksandar Miltenovic ◽  
Radivoje Mitrovic ◽  
Milan Banic

Crossed helical gears are used in cars and many household appliances. The trend towards increased comfort in motor vehicles has led to the utilization of more than a hundred servo-drives in luxury class automobiles. Key advantages of crossed helical gears are their simple and inexpensive design, good noise performance and high ratios that can be realized in one step. Sintered steel is a highly favorable material for wheels in crossed helical gears. They are able to satisfy high performance demands in the areas of wear, fretting, tooth fracture and pitting load capacity. This report describes the results of an examination into the use of the iron-based sintered material Fe1.5Cr0.2Mo with pyrohydrolysis in crossed helical gears, in the areas of wear resistance and other damage types under different speeds and loading conditions.


2020 ◽  
Vol 143 (4) ◽  
Author(s):  
M.R. Kang ◽  
A. Kahraman

Abstract The quasi-static behaviors of a double-helical gear pair is investigated both experimentally and theoretically with the main focus on the influence of the key design and manufacturing parameters associated with double-helical gears, including nominal right-to-left stagger angle, the stagger angle deviation (error) from the nominal stagger angle, and axial gear supporting conditions. On the experimental side, a double-helical gear test setup proposed earlier (Kang, M. R., and Kahraman, A., 2015, “An Experimental and Theoretical Study of Dynamic Behavior of Double-Helical Gear Sets,” J. Sound Vib., 350, pp. 11–29). for studying dynamics of the same system is employed that allows adjustable right-to-left stagger angles, intentional stagger errors, and axial support conditions. Specific measurement systems are developed and implemented simultaneously to measure the static motion transmission error and axial motions of the gears under low-speed conditions, as well as gear root strains to determine right-to-left load-sharing factors. A test matrix that covers wide ranges of stagger angles, intentional stagger error, and axial support conditions is executed within a range of torque transmitted to establish an extensive database. On the modeling side, the measured quasi-static behavior of double-helical gear pairs is simulated by using an existing quasi-static double-helical load distribution model (Thomas, J., and Houser, D. R., 1992, “A Procedure for Predicting the Load Distribution and Transmission Error Characteristics of Double Helical Gears,” World Congress-Gear and Power Transmission, The 3rd World Congress—Gear and Power Transmission, Paris.). Direct comparison of the measurements and predictions of loaded static transmission error, axial play, root stresses, and right-to-left load-sharing factors are used to validate the quasi-static model as well as describing the measured behavior.


Author(s):  
Cheng Wang

The research of transmission efficiency is of great significance for reducing energy consumption and improving the performance of the device. Researchers have done a lot of work on the calculation of transmission efficiency. However, in the present research work, the quantity of planetary gear/star gear is usually not considered and only a planetary gear/star gear is adopted in the gear transmission efficiency. In practice, in order to increase the stiffness and load capacity of gear train, a plurality of planetary gear/star gears is adopted. The closed differential double helical gear train has been widely used in many fields, such as the main reducer of aircraft engine, lifting mechanism, and the power transmission system of marine ships. Therefore, in this paper, the closed differential double helical gear train is taken as the research object and the effect of planetary gear/star gear on the transmission efficiency is analyzed. Firstly, according to the structure of closed differential double helical gear train, related kinematic analysis is given. Secondly, a graph representation is used to characterize the closed differential double helical gear train. According to the theory of virtual power, the power flow direction of closed differential double helical gear train is determined and the value of split power is obtained. According to the input and output values described in graph representation of closed differential double helical gear train, the formula of transmission efficiency is derived and the effects of planetary gear/star gear on transmission efficiency are analyzed. Finally, an illustrative example shows that compared with the theoretical value, the difference considering the effect of planetary gear/star gear on the transmission efficiency of closed differential double helical gear train is two percentage points.


2019 ◽  
Vol 43 (3) ◽  
pp. 283-293
Author(s):  
Dong Liang ◽  
Chuanshan Li ◽  
Chengli Hua ◽  
Tianhong Luo

In this paper, the transmission mechanism of a plastic worm meshed with a steel helical gear is applied to achieve power transmission and motion transfer. Tooth profile equations of the gear pair are derived and general meshing conditions are proposed in terms of gear geometry. A mathematical model of the tooth profiles of the gear pair is established. Contact stress analysis and general evolution law of the tooth profiles are discussed using the finite element method. Material characteristics, mesh generation, contact definition, and constraint conditions are given. For comparison, analysis results of a steel worm meshed with a steel helical gear is also provided. Through the hobbing process, injection molding, and machining center, samples of steel helical gears, plastic worm, and steel worm are completed, respectively. A characteristic test of the transmission mechanism of the plastic worm meshed with a steel helical gear is carried out based on the microtransmission experimental platform. The contrasting results show that the plastic worm has better transmission performance.


2012 ◽  
Vol 271-272 ◽  
pp. 432-436
Author(s):  
Ming Chu Hsieh ◽  
Chia Chun Lai ◽  
Chia Hung Lai ◽  
Kuo Tian Lai

Gears have been extensively employed in transmission machinery. Among the various and variant types of gears, helical gears have the characteristics of low vibration and low noise, and are especially apt for application in industrial machines. This study proposes to use mathematic geometric equations to compose the programming language via which point data are obtained and processed by Solid Works to complete the construction of the model. As for assembly error and stress analysis, the constructed model is then converted into ANSYS Workbench for implementing the stress analysis of the transmission under the condition of ideal assembly and of erroneous assembly. This study focuses on the impact of assembly error on the transmission in regard to the different pressure angles of the driver side of a helical gear with asymmetric teeth. The results show that the bigger the pressure angle of the driver side of the helical gear, the less stress during the transmission. Furthermore, the stress would increase when a minimum axial error is set. In conclusion, assembly error will cause uneven stress distribution, resulting in reduced service life and other problems.


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