Power Losses in Hypoid Gears
(2014) In Diploma work MME820 20141Machine Elements
- Abstract
- The ambition of this thesis was to provide Scania with a program that can calculate power losses in hypoid gears from gear teeth mesh using the programming language Python. The program should be able to calculate power losses on different points on the gear flank to help designers and engineers in the development face of a new axle gear. Because of governmental requirement and costumers’ wish to minimize fuel costs, it is necessary to have better tools to analyze power losses.
The input to the program was output data from the Finite Element program T900. Calculations on oil film thickness were made on theory mainly based on the ISO standards. Different empirical methods for calculating the friction coefficient and two different methods... (More) - The ambition of this thesis was to provide Scania with a program that can calculate power losses in hypoid gears from gear teeth mesh using the programming language Python. The program should be able to calculate power losses on different points on the gear flank to help designers and engineers in the development face of a new axle gear. Because of governmental requirement and costumers’ wish to minimize fuel costs, it is necessary to have better tools to analyze power losses.
The input to the program was output data from the Finite Element program T900. Calculations on oil film thickness were made on theory mainly based on the ISO standards. Different empirical methods for calculating the friction coefficient and two different methods for calculating power losses were implemented. Different torques, speeds and lubrication temperatures were tested in the program and were compared to the different computation models. Some comparisons were also made with tests from Scania.
A distinguishable pattern for most friction coefficient calculation models, is a decreasing efficiency with increasing temperatures on the lubricant of the gear. This is due to sinking viscosities of the lubricant when the temperatures rise. To secure a higher efficiency it is important to have uniform and sufficiently high viscosity on the lubricant on the gear flank.
According to Scania’s sparse test result, which cannot isolate efficiency losses from gear mesh from other losses and was measured with imprecise equipment, the efficiency increases with increasing torque and speed. For almost all friction coefficient calculation models, the efficiency rises with increasing speed which was in accordance with the test results. The efficiency did not increase directly with increasing torque which might be due to the friction coefficient calculation models overestimating the load impact for the friction coefficient. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/4466889
- author
- Ahmad, Hiam
- supervisor
- organization
- course
- MME820 20141
- year
- 2014
- type
- H2 - Master's Degree (Two Years)
- subject
- publication/series
- Diploma work
- report number
- ISRN: LUTMDN/TMME—5005—SE
- ISSN
- ISRN
- language
- English
- id
- 4466889
- date added to LUP
- 2014-06-16 11:06:22
- date last changed
- 2014-06-16 11:06:22
@misc{4466889,
abstract = {{The ambition of this thesis was to provide Scania with a program that can calculate power losses in hypoid gears from gear teeth mesh using the programming language Python. The program should be able to calculate power losses on different points on the gear flank to help designers and engineers in the development face of a new axle gear. Because of governmental requirement and costumers’ wish to minimize fuel costs, it is necessary to have better tools to analyze power losses.
The input to the program was output data from the Finite Element program T900. Calculations on oil film thickness were made on theory mainly based on the ISO standards. Different empirical methods for calculating the friction coefficient and two different methods for calculating power losses were implemented. Different torques, speeds and lubrication temperatures were tested in the program and were compared to the different computation models. Some comparisons were also made with tests from Scania.
A distinguishable pattern for most friction coefficient calculation models, is a decreasing efficiency with increasing temperatures on the lubricant of the gear. This is due to sinking viscosities of the lubricant when the temperatures rise. To secure a higher efficiency it is important to have uniform and sufficiently high viscosity on the lubricant on the gear flank.
According to Scania’s sparse test result, which cannot isolate efficiency losses from gear mesh from other losses and was measured with imprecise equipment, the efficiency increases with increasing torque and speed. For almost all friction coefficient calculation models, the efficiency rises with increasing speed which was in accordance with the test results. The efficiency did not increase directly with increasing torque which might be due to the friction coefficient calculation models overestimating the load impact for the friction coefficient.}},
author = {{Ahmad, Hiam}},
issn = {{ISRN}},
language = {{eng}},
note = {{Student Paper}},
series = {{Diploma work}},
title = {{Power Losses in Hypoid Gears}},
year = {{2014}},
}