Durability enhancement of polymer gear using compressed air cooling

Siddhartha

Proceedings of the Institution of Mechanical Engineers, Part J:

2017

The significance of polymer gears to transmit power and motion is increasing continuously due to their inherent characteristics. Polymer gears have established themselves as attractive alternatives to traditional metal gears in plethora applications. They are light in weight, have lower inertia, and run noiseless than their metal counterparts. This article presents a comprehensive review of the research on polymer spur gears operating under low (0–8 Nm) and moderate (>8 and ≤17 Nm) loading conditions. Different polymers and polymer composites used till date for the fabrication of such gears are included along with different operating conditions. Various design features of polymer gears and tooth modification techniques for the improvement of the performance and durability of these gears have also been included in this review. The aspects of the modeling and simulation studies of the polymer gears are also emphasized in this paper for completeness of the review. The concept of hybrid gears is discussed along with their tribological properties. Various methods of manufacturing of polymer gears and their failure modes are discussed so as to make the article useful for researchers.

Section: Performance Parameters Of Polymer and Polymer Composite Gearsmentioning

confidence: 98%

Polymer spur gears behaviors under different loading conditions: A review

Siddhartha

Proceedings of the Institution of Mechanical Engineers, Part J:

2017

“…Transmission efficiency of polymer gears is also improved with the inclusion of carbon nanotube. 23 Mertens and Senthilvelan 24 enhanced the transmission efficiency of polymer gears by using 2% compressed air cooling at the mating surface of master and test gears.…”

Section: Literature Reviewmentioning

confidence: 99%

Development and investigation on transmission efficiency of functionally graded material-based polybutylene terephthalate spur gears

Proceedings of the Institution of Mechanical Engineers, Part J:

Siddhartha

2019

Application of polymer composite gears is increasing due to their superior properties. They have lower inertia, less weight, and run much quieter than their metal counterparts. In the present work, functionally graded material-based glass fiber reinforced polybutylene terephthalate gears are fabricated with a novel horizontal centrifugal casting technique using an injection molding machine. Conventional technique is used to fabricate homogeneous polybutylene terephthalate gears. Polybutylene terephthalate reinforced with 15 and 30 wt% glass fibers is used to fabricate gears. Unfilled polybutylene terephthalate gear is also manufactured for comparative study. Gradation in functionally graded material gear is verified by scanning electron microscope analysis, and Shore D hardness is measured in three different locations of the fabricated functionally graded material gears. Gradation in functionally graded material gear is also verified by ignition loss test method. Continuous gradation is observed in functionally graded material gear by scanning electron microscope and confirmed by hardness test and ignition loss test. The objective of present work is to investigate and compare the transmission efficiency of homogeneous and functionally graded material gears during operation. A polymer gear test rig is used for the experimental work. Experiments are conducted at various torque and speed combinations for 0.2 million cycles. Life span of fabricated gear is also tested for 10 million cycles. The range of the torque is 0.8–2.6 N m and the range for rotational speed is 500–1400 r/min. The transmission efficiency of the fabricated gears is found to be sensitive to the operating torque.

Proceedings of the Institution of Mechanical Engineers, Part L:

“…The adhesive wear was dominant, and the wear at the tooth pitch region was low compared to root and tip regions. Mertens and Senthilvelan 43 investigated the effect of air cooling on the durability of PP gears. Gears tested without cooling exhibited severe damage compared to the gears tested with cooling.…”

Section: Performancementioning

confidence: 99%

Surface durability of injection-moulded carbon nanotube–polypropylene spur gears

Mertens

Senthilvelan

2016

Self Cite

Short fibre reinforced thermoplastics are being considered for light-and medium-duty engineering applications because of their improved mechanical strength combined with cost-effective advantages. In recent years, the carbon nanotube reinforced thermoplastics are being preferred over the short fibre reinforced thermoplastics because of the absence of directional shrinkage characteristics, directional mechanical and tribological properties. In this work, 1 wt% carbon nanotube-polypropylene material was injection-moulded to spur gears and evaluated for the durability using in-house developed power absorption gear test rig. During testing, the net surface temperature of the test gears and in-line torque available at the driver and driven shafts were continuously measured. The measured torque was used to evaluate the transmission efficiency of the test-steel gear pair. The measured net surface temperature was correlated with the gear failure mode. Test gears were run up to failure or up to 8.6 Â 10 5 cycles, whichever occurred first. Worn-out gear tooth surfaces were observed using an optical and scanning electron microscope to understand the wear mechanism. In the initial stage of service, test gears exhibited less wear near the pitch region compared to the tip and root regions. This behaviour is due to the maximum sliding velocities at the tip and root regions compared to the pitch region. The carbon nanotube-polypropylene gears exhibited lower surface temperature (5À10 C), improved service life (30%À80%) and higher transmission efficiency (1À1.5%) compared to the polypropylene gear.