1、 WORLDWIDE ENGINEERING STANDARDS General Specification GMW3157 Durability Test for Life Assessment of Engine Radial Shaft Lip Seals Copyright 2012 General Motors Company All Rights Reserved April 2012 Originating Department: North American Engineering Standards Page 1 of 25 1 Introduction Note: Noth
2、ing in this standard supercedes applicable laws and regulations. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Scope. 1.1.1 This group of tests establishes the requirements of gas and diesel engine radial lip seal systems. 1
3、.1.2 Criteria. Validation using GMW3157 means: Completing all relevant tests described herein without leakage. Using production-intent design parts in all of the tests. Using production-intent processes whenever possible. Even if production-intent processes are not used, the parts must conform to al
4、l engineering specifications including surface finish. 1.2 Mission/Theme. 1.2.1 This group of tests is suited to the evaluation of passenger car and light duty truck unidirectional rotating crankshaft seals, using both elastomeric and polytetrafluoroethylene (PTFE) lips that experience thermal, rota
5、tional, and environmental inputs during service. 1.2.2 Camshaft. Test camshaft seals at one-half the crankshaft speeds and other deviations as specified (see 1.2.3 and 1.2.4). Written approval of the release engineer must be given for deviations. 1.2.3 This standard is not intended for bi-rotational
6、 (i.e., axle shaft) or reciprocating sealing elements (i.e., valve guide seals, bonded piston rings, etc.) 1.2.4 The Sealrater Test is for Production Part Approval Process (PPAP) validation of multiple tool cavities and non-functional changes to the seal design, contingent on the design passing (or
7、having passed) the lifetime durability test. Changes requiring complete revalidation include, but are not limited to, changes in lip material, seal production processes, mating component surface finish and designed interference (form, fit, and function). The use of the Sealrater test only to satisfy
8、 a revalidation for process changes must be approved by the release, validation, and supplier quality engineers. 1.2.5 Certain applications may not require completion of the mud/slurry test (e.g., camshaft seals or rear crankshaft seals). Written approval of the release engineer must be given for su
9、ch deviations and recorded in the test report. 1.2.6 Representative Parts. Validation tests must use production intent design and/or manufacturing processes parts. Key characteristics of the parts must be measured and documented before the procedure is run. 1.3 Classification. Not applicable. 2 Refe
10、rences Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ASME 95 ISO 4287 ASME B46 ISO 6194-3 ASTM E18 ISO 12103-1 DIN 3761 SAE J946 ISO 2372 2.2 GM Standards/Specifications. 9985522 GMW16077 GMW3059 GMW16078 GMW14872 GMW16095
11、GMW15827 GMW16096 GMW16076 GMW16676 2.3 Additional References. 88861206 GM Service Part for Indicator Dye 88861276 GM Service Part for Indicator Dye RMA 0S6 Rubber Manufacturers Association Bulletin RMA 0S18 Technical Bulletin 3 Test Preparation and Evaluation 3.1 Resources. Copyright General Motors
12、 Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW3157 Copyright 2012 General Motors Company All Rights Reserved April 2012 Page 2 of 25 3.1.1 Calibration. The tes
13、t facilities and equipment shall be in good working order and shall have a valid calibration label. 3.1.2 Alternatives. Alternative test facilities and equipment may also be used to meet global electrical requirements. However, all measuring variables as specified in this standard shall be determine
14、d correctly with respect to their physical definition. 3.1.3 Facilities. 3.1.4 Equipment. All approved labs must have this equipment unless otherwise specified. A schematic of the test system is in Appendix A1 and Appendix A2. Minor variations from the schematic (component layout) between test labs
15、is permitted provided it does not alter test results as verified in a common part test with a qualified lab(s). 3.1.4.1 Rotary Test Unit. The machine shall have a test head for retaining test fluid and positioning the seal(s) on a rotatable shaft supported by an externally mounted spindle. In additi
16、on, the following conditions are required: 3.1.4.1.1 The test head support must be sufficiently rigid to ensure minimum vibration. 3.1.4.1.2 Equipment capable of testing up to 150 mm outer diameter (OD) seal and 100 mm OD shaft diameter. 3.1.4.1.3 It shall be suitably constructed to maintain pressur
17、e and test fluid level required for the test. 3.1.4.1.4 The head shall be equipped with a collector for leak determination. 3.1.4.1.5 It shall be vented to the atmosphere; the length and diameter of vent pipe to be agreed upon between tester and requester. Running pressure and vacuum test will requi
18、re valves to close the vent pipe. 3.1.4.1.6 Internal pressure can be applied to the head with gauging to monitor the intended level. 3.1.4.1.7 The test head shall be designed and constructed to maintain a preset seal bore alignment to the test shaft axis within 0.05mm through the operating temperatu
19、re range. 3.1.4.1.8 Maximum rotational speed up to 8000 rmin-1 (8000 RPM) 3.1.4.1.9 Test temperature range of -40 to 150 C. 3.1.4.1.10 Spindle. The spindle must be capable of cycling and/or maintaining constant shaft speeds within 50 rmin-1 (50 RPM). The spindle must be sufficiently rigid to maintai
20、n shaft run out under dynamic conditions within 0.05mm up to 8000 rmin-1 (8000 RPM). See 3.2.3.4 3.1.4.1.11 Programmable rotational test equipment with a peak shaft speed of 8000 min-1 (8000 RPM) peed accuracy of 50 min-1 (50 RPM) adjustable shaft eccentricity of 0.50 0.05 mm total indicator reading
21、 (TIR), adjustable shaft to bore alignment of 0.50 0.05 mm TIR, and shaft fore-aft reciprocation of 1.0 0.1 mm. 3.1.4.1.12 Test head may be heated electrically and/or by heat transfer fluid. 3.1.4.2 Thermal Test Chamber with Temperature Controller. Chamber internal volume sufficient to house the com
22、ponents scheduled for test which can cycle from -40 to 150 3 C (-40 to 302 5 F) at a rate of 2 h to reach temperature limits and hold it for the required cycle limits (Tables 8 and 9). Test chamber must have plumbing and wiring access hole(s). Temperature controller with programming feature must mai
23、ntain 3 C of set temperature. Unit (with temperature indicator) must have multiple thermocouple channels to monitor chamber and part temperature. Sensor input must accept designated temperature measuring device. Due to different mass and size of rotary test heads, a higher electric or fluid heat com
24、pensation may be required to comply with the test cycle requirements. 3.1.4.3 Fume Hood or Vent. Appropriate industry approved construction and performance to prevent vapors as required by regulation. 3.1.4.4 Temperature Monitor. Computer controlled data analyzer capable of measuring in -40 to 150 C
25、 range to 3 C accuracy. Accepts designated temperature measuring devices. 3.1.4.5 Part Temperature Measuring Device. Capable of measuring in -40 to 150 C range to 3 C accuracy. For example; these two thermocouples must meet these requirements: A resistive temperature differential (RTD) or, American
26、National Standards Institute (ANSI) Type J or Type T (blue), sheathed solid bare wire diameter (gauge) with wire insulation. See 4.2.3.4.3 and 4.2.3.4.4 for thermocouple locations. 3.1.4.6 Device Capable of Counting Revolutions. Count/record the total number of shaft rotations using an encoder to me
27、asure speed. Dynapar brand model number H23036010024E meets the requirements. 3.1.4.7 Thermocouple Locations. Use thermocouples to monitor, maintain and record fluid media inlet temperature to achieve the Table 6 fixture temperatures. Thermocouple (T/C) at the oil inlet to the spray ring or immersed
28、 in oil Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW3157 Copyright 2012 General Motors Company All Rights Reserved April 2012 Page 3
29、of 25 near the bottom of the rotary test unit. For test facilities heating the test head, for thermal cycle conditions (see 4.2.2.2) mount a T/C to control the band heater around the rotary test unit. 3.1.4.8 Fluid Circulatory System. 3.1.4.8.1 Reservoir. External to thermal chamber with sufficient
30、volume capacity to accommodate fluid expansion. A typical capacity is 4 to 10 L (1 to 3 gal) depending on the number and size of components tested. Reservoir is fabricated from non-reactive material to fit the requirements. The setup must be capable of maintaining test fluid temperature within 3 C.
31、Heat must be supplied so that the test fluid is warmed uniformly. Acceptable methods are immersion heaters, external electrical heaters with wall temperature controllers or circulation of externally heated fluid. Chromalox (Emerson Electric) or Mohawk units have a thermocouple for controlling/monito
32、ring fluid temperature leaving fluid pump. A high limit thermocouple to monitor reservoir fluid temperature and shutdown the system is recommended. Float level controls with alarm to prevent overfill or overflow are optional. Note: Use the minimum amount of oil needed to maintain the proper fixture
33、fluid feed rates. This promotes reservoir oil degradation by oxidation and heat. Maintain Table 1 Test Conditions. Table 1: Functional Tests and Conditions Test Type/Equipment Purpose/Description Evaluation Criteria Sealrater A General Performance gas and diesel engine/Rotary Test Unit To screen new
34、 designs and a quality control for evaluating material, new tool and process changes. The assembly, including gasket/seal, fasteners and structural interfaces is cycled thermally, while the shaft speed is held constant and the lip is exposed to a constant level of oil (see Table 7, fluid level). Oil
35、 Leak Lifetime Durability B1 Durability gas engines/Rotary Test Unit To evaluate the durability of oil seals under high speed and low lubrication. The assembly, including gasket/seal, fasteners and structural interfaces is cycled on a thermal and rotational schedule while oil is sprayed internally.
36、The effect of crankcase pressure and vacuum on seal durability is part of the test schedule. Pressure represents naturally aspirated and charged engine applications. Oil leak at shaft Oil leak around case Shaft wear Seal lip conditions: crack, hard, tear, wear, soft, debris in grooves, and coking B2
37、 Durability diesel engines/Rotary Test Unit To evaluate the durability of oil seals under moderate speed. The assembly, including gasket/seal, fasteners and structural interfaces is cycled on a thermal and rotational schedule while oil is sprayed internally. The effect of crankcase pressure and vacu
38、um on seal durability is part of the test schedule. Pressure represents naturally aspirated and charged engine applications. For all diesels except Duramax. Oil leak at shaft Oil leak around case Shaft wear Seal lip conditions: crack, hard, tear, wear, soft, debris in grooves, and coking B3 Durabili
39、ty diesel engines/Rotary Test Unit Same as B2. Duramax only Same as B2 Dust C Environmental Contamination Resistance/Rotary Test Unit To evaluate the durability of oil seals to dust. The assembly, including gasket/seal, fasteners and structural interfaces are exposed to a specified mixture of airbor
40、ne contaminants (Arizona dust) while the shaft rotates and oil is sprayed internally. It is desirable to represent the dust-exclusion function of the damper itself on this test, either using the actual damper or a test part that provides similar characteristics. Oil leak at shaft Oil leak around cas
41、e Shaft wear Seal lip conditions: crack, hard, tear, wear, soft, debris in grooves, and coking Slurry D N/mm 3 minimum Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLD
42、WIDE ENGINEERING STANDARDS GMW3157 Copyright 2012 General Motors Company All Rights Reserved April 2012 Page 4 of 25 3.1.4.8.2 Pump and Heater - Oil, Circulating. A typical capacity is 24 L per minute (6 U.S. gal/minute), 35 kPa to 105 kPa (5 psi to 15 psi) pressure range. Chromalox (Emerson Electri
43、c) or Mohawk units meet the requirements. The pump is mounted to the feed line between the reservoir and rotary test unit. 3.1.4.8.3 Secondary Pump (optional). A horsepower (HP), 110 V mounted on fluid return line from test head drain to reservoir. 3.1.4.8.4 Spray Ring (Tests B1 thru B3). A 135 mm s
44、pray ring. Provisions in the rotary test unit must permit fore to aft positioning for a proper fluid spray. The fluid entry connection to the ring may be shaped to provide ring location flexibility provided the required spray pattern is achieved and no fluid leaks from the connection. See Appendix B
45、, Figure B1 Spray Ring. 3.1.4.8.5 Delivery Lines - Supply and Return. Use compression, pipe threads or flare fittings for all connections. Use 15.7 mm (0.62 in) inner diameter (ID) 13 mm ( in) national pipe thread (NPT) minimum rated above maximum system test pressures and pulses, and 9.5 mm ( in) I
46、D 13 mm ( in) OD optional minimum for test heads of small depth. For lower pressure media systems, non-corrosive, rigid stainless steel lines with quick connect end fittings are possible. 3.1.4.8.6 Valves and Pressure Gauges. Locate solenoid valve between the reservoir and rotary test head to preven
47、t oil starvation/surging during startup and preheat conditions. Closed loop function preventing oil from getting to the test head. 3.1.4.8.7 Supply and Return Lines. These components are made from non-corrosive material(s) that withstand the fluid, temperature and pressure environment of this test.
48、Rotary test units have single fluid entry/exit accommodating up to two seals. The system design and features must maintain suitable fluid pressure to permit proper internal spray pattern with gauging and flow meters to confirm and control settings. 3.1.4.9 Data Acquisition System. A recording system
49、 to gather and store data from the measurement system sufficient to document that the test was run in conformance with the specification (i.e., that speed and temperature set points were achieved and held for the specified time). See Section 8 for list of parameters. 3.1.4.10 Changes in Test Equipment. As components are replaced, newer versions represent changes that could alter a test cell result. The GM Powertrain Technical Specialist shall
