In the KISSsoft shaft calculation, the proof of fatigue strength can be performed by generating an equivalent stress verification according to the FKM Guideline.
SMT's May workshops aim to give attendees the tips and tricks needed to further improve the fidelity of the MASTA model. In this workshop, SMT engineers will go through some of the tools available including:
A calculation-based study of different variants with regard to contact ratio and tooth root geometry to compare the results from the 2019 version of ISO 6336 to the previous version, released in 2006.
This article presents an analysis of asymmetric tooth gears considering the effective contact ratio that is also affected by bending and contact tooth deflections. The goal is to find an optimal solution for high performance gear drives, which would combine high load capacity and efficiency, as well as low transmission error (which affects gear noise and vibration).
Forest City Gear applies advanced gear shaping and inspection technologies to help solve difficult lead crown correction challenges half a world away. But these solutions can also benefit customers much closer to home, the company says. Here's how…
It’s a brave, new hardware-software world out there. Players in the worldwide gear industry who don’t have plenty of both run the risk of becoming irrelevant—sooner than later.
The first edition of the international calculation method for micropitting—ISO TR 15144–1:2010—was just published
last December. It is the first and only official, international calculation method established for dealing with
micropitting. Years ago, AGMA published a method for the calculation of oil film thickness containing some comments
about micropitting, and the German FVA published a calculation method based on intensive research results. The FVA and the AGMA methods are close to the ISO TR, but the calculation of micropitting safety factors is new.
In this article, the authors calculated the numerical coordinates on the tooth surfaces of spiral bevel gears and then modeled the tooth profiles using a 3-D CAD system. They then manufactured the
large-sized spiral bevel gears based on a CAM process using multi-axis control and multi-tasking machine tooling. The
real tooth surfaces were measured using a coordinate measuring machine and the tooth flank form errors were detected
using the measured coordinates. Moreover, the gears were meshed with each other and the tooth contact patterns were investigated. As a result, the validity of this manufacturing method was confirmed.
This paper deals with analysis of the load sharing percentage between teeth in mesh for different load conditions
throughout the profile for both sun and planet gears of normal and HCR gearing—using finite element analysis.
(FEA).
When you push 850 horsepower and 9,000 rpm through a racing transmission, you better hope it stands up. Transmission cases and gears strewn all over the racetrack do nothing to enhance your standing, nor that of your transmission supplier.
This paper will demonstrate that, unlike commonly used low-contact-ratio spur gears, high-contact-ratio spur gears can provide higher power-to-weight ratio, and can also achieve smoother running with lower transmission error (TE) variations.
Welcome to Revolutions, the column that brings you the latest, most up-to-date and easy-to-read information about the people and technology of the gear industry.
A major source of helicopter cabin noise (which has been measured at over 100 decibels sound pressure level) is the gearbox. Reduction of this noise is a NASA and U.S. Army goal. A requirement for the Army/NASA Advanced Rotorcraft Transmission project was a 10 dB noise reduction compared to current designs.
In some gear dynamic models, the effect of tooth flexibility is ignored when the model determines which pairs of teeth are in contact. Deflection of loaded teeth is not introduced until the equations of motion are solved. This means the zone of tooth contact and average tooth meshing stiffness are underestimated, and the individual tooth load is overstated, especially for heavily loaded gears.
This article compares the static transmission error and dynamic load of heavily loaded, low-contact-ratio spur gears when the effect of tooth flexibility has been considered and when it has been ignored. Neglecting the effect yields an underestimate of resonance speeds and an overestimate of the dynamic load.
Spur gear endurance tests were conducted to investigate the surface pitting fatigue life of noninvolute gears with low numbers of teeth and low contact ratios for the use in advanced application. The results were compared with those for a standard involute design with a low number of teeth. The gear pitch diameter was 8.89 cm (3.50 in.) with 12 teeth on both gear designs. Test conditions were an oil inlet temperature of 320 K (116 degrees F), a maximum Hertz stress of 1.49 GPa (216 ksi), and a speed of 10,000 rpm. The following results were obtained: The noninvolute gear had a surface pitting fatigue life approximately 1.6 times that of the standard involute gear of a similar design. The surface pitting fatigue life of the 3.43-pitch AISI 8620 noninvolute gear was approximately equal to the surface pitting fatigue life of an 8-pitch, 28-tooth AISI 9310 gear at the same load, but at a considerably higher maximum Hertz stress.
The use of plastic gearing is increasing steadily in new products.
This is due in part to the availability of recent design data. Fatigue
stress of plastic gears as a function of diametral pitch, pressure angle,
pitch line velocity, lubrication and life cycles are described based
on test information. Design procedures for plastic gears are presented.
Gear shaving is a free-cutting gear finishing operation which removes small amounts of metal from the working surfaces
of the gear teeth. Its purpose is to correct errors in index, helical angle, tooth profile and eccentricity.
