摘要:

A study of the wear behavior of several classes of potential cage materials for aircraft gas turbine bearings was conducted, using a special wear-testing machine to approximate the projected service conditions of such bearings.

ISSN:0569-8197    

DOI:10.1080/05698195808972308

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

The failure mechanisms of grease lubricated ball bearings operating in the DN range from 1.0 × 106to 2.0 × 106was studied. A new rig capable of controlled operation of 20 and 25 mm ball bearings at speeds up to 100,000 rpm is described. Ball separator design seems to be a very important factor and a lightweight single piece machines outer ring controlled ball separator appeared to give the best results. In general, mechanical factors such as vibration, bearing design, bearing fit and tolerances, dynamic balance, load alignment, etc., have more influence on the performance of the bearings studied than gross grease variables. Under ideal conditions it is indicated that adequate lubrication with grease is possible for periods over 100 hours. However, under the test conditions generally in existence in the ultra high speed rigs grease lubrication was only adequate for very short periods.

ISSN:0569-8197    

DOI:10.1080/05698195808972309

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

An instrument to evaluate grease or ball bearing performance at high temperatures under actual operating conditions has been developed. Operation of the bearing in an oxygen atmosphere has considerably reduced the total testing time required. By measuring the rate of oxygen consumption during a test, data on the chemical changes taking place in the grease are obtained, and the time of grease failure can be pinpointed quite accurately and reproducibly.

ISSN:0569-8197    

DOI:10.1080/05698195808972310

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

A simple bench test for evaluating materials and lubricants under actual rolling-contact stresses is described. Stress-life relationships for mineral-oil lubricated SAE 52100 balls and AISI M-50 (MV-1) tool steel cylinders compared favorably with those obtained in full-scale bearings. Most failures originated in subsurface shear and closely resembled those obtained in bearings.

ISSN:0569-8197    

DOI:10.1080/05698195808972311

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

A series of fatigue life tests on aircraft gear box size (45 mm bore) roller bearings were conducted with various aircraft gas turbine lubricants and with specific reference to Mil-L-7808 and variations thereof. It is shown that the 7808 lubricants generally cause a marked reduction in fatigue life as compared to that obtained with a medium viscosity mineral oil. It is also shown that lubricant bulk viscosity is a major factor in life. Subsequent testing demonstrated that the addition of thickeners to 7808 lubricants and formulations of this lubricant for a high Ryder Gear Rating are not effective in raising the fatigue life. It also appears that the SOD lead corrosion test is not pertinent in bearing life. Suggestion is made that the 7808 specification be relaxed to allow of higher viscosity for heavily loaded bearings as in gear boxes.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Toronto, Canada, October, 1957.

ISSN:0569-8197    

DOI:10.1080/05698195808972312

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

This paper presents some of the results of a recent investigation on the effect of lubricants on gear tooth surface fatigue (pitting). The work described comprises the development of a laboratory test procedure for exploratory purposes, and the determination of the performance of a number of lubricants using this procedure. It was found that bulk lubricant viscosity, as measured by the conventional viscometric method, did not have a predominant effect on gear tooth surface fatigue. Examination of the development of scuffing and pitting on the gear teeth indicates that the initial incidence of scuffing and the initial incidence of pitting were unrelated. It was further noted that as pitting became advanced, severe scuffing of the pitted teeth would almost invariably result. On the other hand, there was no evidence that severe scuffing would lead to gear tooth pitting.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Toronto, Canada, October, 1957.

ISSN:0569-8197    

DOI:10.1080/05698195808972313

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

The Modified SAE EP Lubricants Testing Machine and the McKee EP Lubricants Testing Machine use two contacting cylindrical test cups which are rotated at different speeds under load to give combined rolling and rubbing action typical of gear teeth. With these machines methods were developed for evaluating the anti-wear and the load-carrying properties of turboprop lubricants. Data are presented for 31 oils tested on the above machines, and for 25 of these oils also tested for stability at high temperatures on the McKee Oil Stability Apparatus.Contributed to the American Society of Lubrication Engineers by the author. Manuscript received 1 October 1957.

ISSN:0569-8197    

DOI:10.1080/05698195808972314

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

Interest is growing concerning the influence of polymeric additives upon the viscosity of mineral oils at extremes of temperature, pressure, and shear. In this paper the author discusses the viscometry of mineral oils and mineral oil-polymer blends at moderate temperatures and high shear and at low temperatures and low shear.

ISSN:0569-8197    

DOI:10.1080/05698195808972315

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

The experimental check described proved that viscosity measurements on polymer modified oils with rotational and capillary viscometers can be successfully correlated. The rules for this are the same as those used for other non-Newtonian liquids (solutions of high polymers); namely, viscosity vs. the rate of shear at the wall, R. This is valid to at least 106sec−1.Contributed by the ASLE Technical Committee on Lubrication Fundamentals, and presented at the Annual Meeting of the American Society of Lubrication Engineers held in Detroit, Michigan, April. 1957.

ISSN:0569-8197    

DOI:10.1080/05698195808972316

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

The actual mechanism of radiation damage to materials by reactor radiation is a matter of prime importance. Radiation damage to covalent compounds such as organic lubricants by reactor radiation is due primarily to secondary ionization caused by fast neutrons, slow or thermal neutrons, and gamma rays, and is not largely due directly to the initial interaction of any of these three types of radiation with the nuclei or atoms of the organic compounds. The amount of energy absorbed by a given material from these various types of radiation can be calculated, and the actual damage incurred is a function of the energy absorbed. Based upon available experimental test data of radiation damage to various organic materials and based upon the equivalent absorbed energy-equivalent damage concept, various generalizations regarding organic lubricating materials can be made.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Atlantic City, N.J., October, 1956.

ISSN:0569-8197    

DOI:10.1080/05698195808972317

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor