Access the full text.
Sign up today, get DeepDyve free for 14 days.
References for this paper are not available at this time. We will be adding them shortly, thank you for your patience.
TORQU E converters for commercial road vehicles are increasing in popularity and the questio n of the most suitabl e fluid to use wit h the m ha s been the subject of muc h experi men t for several years. A paper was recently presente d before the S.A.E. at Pittsburgh b y Mr. E. F . Collins of th e G.M.C. Truck & Coach Division and thi s describes current practic e in the U.S.A. Th e following is an abstrac t of tha t paper. Early Systems. Th e first torque con verter s employed a sep arat e fluid system and bot h fuel oil an d kero sen e were used. The drawback s to this syste m were cavitation, bubbling, fluid breakdown 2,000 miles, but using the additive oil, over 25,000 an d deposits. In order to avoid th e need for a separ miles have been run without any attention to these at e fluid system it was the n decided t o use engine fuel. parts . Such methods were not suitable for petrol vehicles Fluid Properties. an d therefore a separate system was again reverted to Mr. Collins concluded that the necessary character which ha d a numbe r of modifications and this system istics for torque converter fluids are as follows :— is used, fundamentally, today. It is illustrated. (1) Viscosity—An oil of 55/65 S.U.S. at 100°F. Fundamentals of Modern System. appear s to satisfy present requirements. I t will be noted tha t th e fluid from a separate tank (2) Flash Point and Volatility—Since the convertor is drawn through a filter by an engine driven pump normall y operates at 200/250°F. maximum, it an d delivered to th e turbine, it also flows through the ha s been found that if the volatility is between cooler by turbine pressure. A line from the top of 400 and 700° F. (as determined by A.S.T.M. th e cooler returns the fluid to the supply tank. In metho d D.158-41 distillation test) an adequate th e early stages of this design, and since no special margin of safety is provided. fluid was generally available, diesel fuel oil continued (.'!) Anti-Rust and Anti-Corrosion Properties—The t o be used. The difficulties with high fluid con need for these are obvious since the rusting of sumption , vaporisation, cavitation and oxidation steel turbine parts and supply tanks also corro caused a lot of trouble due to deposits in filters, sion of brass plates, must be avoided. rustin g and varnishing of turbine parts. (4) Miseability Tests—It is necessary to know I t was then found that a more viscous fluid whethe r the sample will be miseable and com eliminate d most of these difficulties and bus oper patibl e with other fluids. ator s were soon using a product known as " Mineral (5) Foam Test—Foaming can be damaging in any Seal Oil " or "30 0 Burning oil." Due to the fact, hydrauli c system. however, that the tank is the coolest point in the (0) Pour Point—Liquids having pou r poin t of—10°F. system , oxidation still occurred and the oxidation or below appear to be satisfactory. product s which were soluble in hot fluid became (7) Effect on Turbine Seals—Suggested test is to insoluble in th e supply tank and settled out. hea t the seals in the fluid for extended periods u p to 300°F. Seals which do not harden after Detergent Additives Employed. 70 hours of this treatment are generally con Havin g found a very suitable fluid system it sidered acceptable. remaine d to find the best type of fluid and experi (8) Cleanliness in Operation—It is believed tha t the ment s confirmed that a light spindle oil of Pennsyl- detergenc y and dispersancy which are provided vanian or other base containing a certain percentage b y the heavy duty additive are important. of heav y dut y engine oil additiv e filled th e bill. Pre- (9) Oxidation Stability—Since the system is inde viously it had been th e practice to drain Mineral Seal penden t and receives no continuous supply of Oil every 6/9,000 miles and to clean th e filter every new fluid, resistance to oxidation is important. Scientific LUBRICATION March. 1949
Industrial Lubrication and Tribology – Emerald Publishing
Published: Mar 1, 1949
You can share this free article with as many people as you like with the url below! We hope you enjoy this feature!
Read and print from thousands of top scholarly journals.
Already have an account? Log in
Bookmark this article. You can see your Bookmarks on your DeepDyve Library.
To save an article, log in first, or sign up for a DeepDyve account if you don’t already have one.
Copy and paste the desired citation format or use the link below to download a file formatted for EndNote
Access the full text.
Sign up today, get DeepDyve free for 14 days.
All DeepDyve websites use cookies to improve your online experience. They were placed on your computer when you launched this website. You can change your cookie settings through your browser.