SAE J1971 pdf download
SAE J1971 pdf download.Radial Lip Seal Torque-Measurement Method and Results.
This SAE Recommended Practice provides information on procedures, tools, and fixtures useful in determining frictional torque measurement of radial lip oil seals. Information on the effect of various operational environments on oil seals are discussed and a means of calculation of power consumption of seals is provided.
2. References
2.1 Applicable Publications—The followin9 publications form a part of this specification to the extent specified herein. Unless otherwise specified, the latest issue of SAE publications shall apply.
2.1.1 SAE PunucATloNs—Available from SAE, 400 Commonwealth Drive. Warrendale. PA 15096-0001.
SAE JI 10—Seals Testing of Radial Lip
SOLE J946—Application Guide to Radial Lip
SAE Ji 901 —Lip Force Measurement. Radial Lip Seals
SAE Paper 841145-—The Effect of Operating Parameters Upon Radial Lip Seal Performance, September. 1984, I… A. Hcxve, CR Industries, Elgin, IL
2.1.2 RMA PuBucATs—Available from Rubber Manufacturers Association, Washington DC.
RMA OS-i—Shaft Finishing Techniques for Rotating Shaft Seals, AMA Handbook
RMA OS-6— Radial Lip Type Shaft Seals—Radial Force Measurement, RMA Handbook
RMA OS-9—The Effect of Test Variables Upon Shaft Lip Seal Performance, AMA Technical Bulletin
AMA OS-i 5—Measunng Radial Lip Seal Torque and Power Consumption, AMA Technical Bulletin
3. RadIal Lip Oil Seal Frictional Torque—The radial lip oil seal is designed to retain lubncants and exclude contaminants, Retaining lubricants depends upon maintaining an interference fit between the shaft and the sealing lip throughout the life of the seal (Figure 1). The interference fit between the shaft and the sealing lip results in radial forces that create the sealing force. These forces also generate frictional torque when the shaft rotates. This frictional torque consumes power and reduces the efficiency of operating equipment. Frictional torque also generates heat that can be detrimental to the sealing element, the lubricant, and the beanngs contained wdhin the mechanical device, It is, thus, important to define consistent methods of measuring seal torque. The methods described and data generated in mis document pertain to a radial lip oil seal operating with oil only as the lubricant. Seals with grease as a lubricant may require different test procedures. The torque trend of seals operating in grease may not parallel the trends discussed in this document.
4.1.3 The shaft must conform to SAE standards with a surface roughness of 0.25 to 0.50 pm (10 to 20 pin) Ra, a machine lead angle of 0 mm ±3 mm and a hardness of Rockwell C30 minimum. (Reference SAE 3946 and SAE Ji 10.)
4.1.4 The dynamic runout of the shaft shall be measured with a dial indicator and should be less than 0.08 mm (0.003 in) TIR.
4.1.5 The seal lip ID and radial force (reference SAE J1901 and SAE 841145) shall be measured and recorded.
4,1.6 The test shall normafly be conducted at room temperature. If vakes at elevated temperatures are desired. then the test fixture shown in Figure 2 should be equipped with healers and controlled within ±3 VC (±5 °F). It is recommended that the hxture head be filled with a fluid to promote heat transfer and prevent hot spols
4.1.7 The seal lip should be lubricated lightly with oil (SAE 30 engine oil is recommended).
4.1.8 The seal shall be installed in the fixture.
4.1.9 A torque wrench divided into 0.01 N-rn (1.43 Oz-in) increments or smaller is placed on the end of the shaft and turned slowly (about 60 rpm). The torque required to move the shaft is recorded. This procedure will provide relative information for guidance only. It will not predict the torque of a seal operating under actual application conditions.
4.2 Torque Measurement with an Electronic Device—An electronic transducer can be placed between a drive motor and a test head (Figure 3) to provide accurate torque readings at a variety of application conditions (shaft speed, sump temperature, pressure, etc.). The test head must meet the standard SAE requirements (Reference RMA OS-i). II is recommended that air bearings be used to reduce system friction. The intrinsic friction of the spindle assembly should be held to less than 1% of the seal torque to be measured. This can be verified by measuring the spindle torque without a seal installed. The recommended test procedure is:
4.2.1 The shaft size shall be recorded and must conform to the SAE standards of Table 1 (Reference SAE 3946).
4.2.2 The shaft must conform to SAE standards with a surface roughness of 0.25 to 0.50 pm (10 to 20 pin) Ra. a machine lead angle of 0 mm ± 3 mm and a hardness of Rockwell C30 minimum (Reference SAE J946 and SAE Ji 10).
4.2.3 The dynamic runout of the shaft shall be measured with a dial indicator and recorded.
4.2.4 The seal lip ID and radial load (Reference SAE J1901 and SAE 841145) shall be measured and recorded.
4.2.5 The seal shall be installed in a suitable end plate and assembled onto the housing.
