Comparative Fatigue Resistance of Fiber Reinforced Nylon 6 Gears

1995 ◽  
Vol 117 (1) ◽  
pp. 193-198 ◽  
Author(s):  
G. Crippa ◽  
P. Davoli

The fatigue-life diagrams of injection-molded nylon 6 gears with different reinforcements are shown for various lubrication modes (dry, grease, splash oil lubrication) and for different meshing combinations (plastic/plastic and steel/plastic gears). Tests using a suitably designed back-to-back rig have been carried out, and the results compared with previous experiments, performed using unreinforced nylon 6 gears. 232 gears (70 in unreinforced and 162 in differently filled nylon) were tested. More than 700 · 106 cycles have been totalled. From test data, and from the “matrix” of the gear/pinion material combination, the capabilities of differently reinforced nylon 6 gears in terms of fatigue and wear resistance have been outlined. These capabilities are the basis for a proper material selection in plastic gear design.

Author(s):  
Giuseppe Crippa ◽  
Piermaria Davoli

Abstract The fatigue-life diagrams of injection-molded nylon 6 gears with different reinforcements are presented for various lubrication modes (dry, grease, splash oil lubrication) and for different meshing combinations (plastic/plastic and steel/plastic gears). Tests have been carried out with a properly designed back-to-back rig; results are compared with previous experiments, performed with unreinforced nylon 6 gears. Tested gears have been 232 (70 in unreinforced nylon and 162 in differently filled polyamides). More than 700·106 cycles have been totalised. From test data, and from the “matrix” of gear/pinion material combination, the capabilities of differently reinforced nylon 6 gears for fatigue and wear resistance have been outlined. These capabilities are the basis for a proper material selection in plastic gear design.


2008 ◽  
Vol 4 (1) ◽  
pp. 1-26
Author(s):  
Gábor Kalácska

Research was performed on the friction, wear and efficiency of plastic gears made of modern engineering polymers and their composites both in a clean environment (adhesive sliding surfaces) and in an environment contaminated with solid particles and dust (abrasive), with no lubrication at all. The purpose is to give a general view about the results of abrasive wear tests including seven soil types as abrasive media. At the first stage of the research silicious sand was applied between the meshing gears and the wear of plastic and steel gears was evaluated and analyzed from the point of different material properties (elongation at break, hardness, yield stress, modulus of elasticity) and its combinations. The different correlations between the experienced wear and material features are also introduced. At the second stage of the project the abrasive sand was replaced with different physical soil types. The abrasive wear of gears is plotted in the function of soil types. The results highlight on the considerable role of physical soil types on abrasive wear resistance and the conclusions contain the detailed wear resistance. The results offer a new tribology database for the operation and maintenance of agricultural machines with the opportunity of a better material selection according to the dominant soil type. This can finally result longer lifetime and higher reliability of wearing plastic/steel parts.


2006 ◽  
Vol 977 ◽  
Author(s):  
Toshihira Irisawa ◽  
Masatoshi Shioya ◽  
Haruki Kobayashi ◽  
Junichi Kaneko

AbstractThe wear resistance and the mechanical properties of polymer matrix composite fibers filled with inorganic fillers have been investigated in order to find out the way to increase the wear resistance of the fibers without losing tensile modulus and strength. Nylon 6 and poly(ethylene terephthalate) have been used as the matrix polymer and aluminum borate whisker and carbon nanotube have been used as the fillers. The wear resistance of the fibers has been evaluated by observing the fiber cross section after the side of the fiber was worn using a rotating drum covered with abrasive paper. The wear resistance of the nylon 6 and PET fibers was increased by the addition of these fillers without the loss of tensile modulus and strength. The effects of the addition of the fillers on the wear resistance have been compared with the effects of stretching and heat treatment of the fibers.


Author(s):  
Rod Kleiss ◽  
Frank J. Ferfecki

Much has been written about the advances in polymer gearing over the past few years. After fitful starts in toys and consumer products, the design and quality of these gears have improved dramatically. Materials advances over the past 20 years have been significant as well. This paper describes the methodology of designing a net shape PolyEtherEtherKetone (PEEK) injection molded gear for an automotive mass balance system. The case study referenced (ref 1) shows that, when compared to the high quality ground iron gears in the same system, a net shape injection molded PEEK polymer gear provides a 3db noise reduction, as much as 9% reduction in power consumption, a 69% mass reduction and meets the application durability requirements. The paper describes the design of the injection molded gear’s unique tooth profile, material selection, part design, mold design, and inspection methods. The paper focuses on the differences in gear design and inspection methods between injection molded gears and their metal counterparts.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4254
Author(s):  
Paulina A. Quiñonez ◽  
Leticia Ugarte-Sanchez ◽  
Diego Bermudez ◽  
Paulina Chinolla ◽  
Rhyan Dueck ◽  
...  

The work presented here describes a paradigm for the design of materials for additive manufacturing platforms based on taking advantage of unique physical properties imparted upon the material by the fabrication process. We sought to further investigate past work with binary shape memory polymer blends, which indicated that phase texturization caused by the fused filament fabrication (FFF) process enhanced shape memory properties. In this work, two multi-constituent shape memory polymer systems were developed where the miscibility parameter was the guide in material selection. A comparison with injection molded specimens was also carried out to further investigate the ability of the FFF process to enable enhanced shape memory characteristics as compared to other manufacturing methods. It was found that blend combinations with more closely matching miscibility parameters were more apt at yielding reliable shape memory polymer systems. However, when miscibility parameters differed, a pathway towards the creation of shape memory polymer systems capable of maintaining more than one temporary shape at a time was potentially realized. Additional aspects related to impact modifying of rigid thermoplastics as well as thermomechanical processing on induced crystallinity are also explored. Overall, this work serves as another example in the advancement of additive manufacturing via materials development.


Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1235
Author(s):  
Bidita Salahuddin ◽  
Rahim Mutlu ◽  
Tajwar A. Baigh ◽  
Mohammed N. Alghamdi ◽  
Shazed Aziz

Passive vibration control using polymer composites has been extensively investigated by the engineering community. In this paper, a new kind of vibration dampening polymer composite was developed where oriented nylon 6 fibres were used as the reinforcement, and 3D printed unoriented nylon 6 was used as the matrix material. The shape of the reinforcing fibres was modified to a coiled structure which transformed the fibres into a smart thermoresponsive actuator. This novel self-reinforced composite was of high mechanical robustness and its efficacy was demonstrated as an active dampening system for oscillatory vibration of a heated vibrating system. The blocking force generated within the reinforcing coiled actuator was responsible for dissipating vibration energy and increase the magnitude of the damping factor compared to samples made of non-reinforced nylon 6. Further study shows that the appropriate annealing of coiled actuators provides an enhanced dampening capability to the composite structure. The extent of crystallinity of the reinforcing actuators is found to directly influence the vibration dampening capacity.


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