1、GM DAEWOO Auto & Technology EDS Engineering, GM DAEWOO Auto & Technology Standards BEARINGS FOR STRUT MOUNTS Do Not Use on New Programs. Being Replaced by GMW14251 EDS-T-2517 ISSUED DATE: 1996. 07. 10 REVISED DATE: 2008. 10. 23 VERSION: 3 (Superceded) EDS-T-2517BEARINGS FOR STRUT MOUNTS PAGE: 1/3 IS
2、SUED DATE: 1996. 07. 10 REVISED DATE: 2008. 10. 23 VERSION: 3 GM DAEWOO Auto & Technology Note: This standard may be applied only for current project (incl. T255 Program). It is Superceded for all future projects and replaced by GMW14251. 1. PURPOSE Service life determination. 2. EQUIPMENT Test setu
3、p as shown in Fig. 1 and 2 using 2 air actuators DN 200 - 100 for the axial force 2 air actuators DN 125 - 100 - A for the radial force 1 feeding device to induce the steering movement X 70 - 250 - B 6 load cells to survey axial - radial force and friction torque of the bearing and test amplifier an
4、d X-Y-recorder 2 attachments test bearings various adapters, pneumatic and electric controllers 2 hot air blowers The test stand is so designed that by replacing the attachments and the adapters, any production strut mount bearing may be tested. 3. PROCEDURE 3.1. Test preparation 3.1.1. Lubricate th
5、e ungreased bearings to drawing specification. 3.1.2. Insert test bearing into hub (firm seat of outer ring) and connect to production shock absorber piston rod as specified on the drawing. 3.1.3. Bearings with fractured outer ring are to be installed in the fixture so that the radial force acts on
6、the fracture in the main direction of stress. 3.1.4. For bearings which are pretensioned in axial direction, the tightening torque is to be determined before the test and the residual torque after the test. 3.2. Test sequence 3.2.1. Bearings must be tested under axial pulsating compression load Fax=
7、 Fm Faand radial alternating load Frad = Frat a simultaniously induced angular movement = 45 until the theoretical running time is reached. EDS-T-2517BEARINGS FOR STRUT MOUNTS PAGE: 2/3 ISSUED DATE: 1996. 07. 10 REVISED DATE: 2008. 10. 23 VERSION: 3 GM DAEWOO Auto & Technology 3.2.2. Heat input duri
8、ng the entire test time (T bearing outer ring 333 K 5 K (60 5 K). 3.2.3. The friction torque is to be measured before the test and after reaching the theoretical running time. 3.2.4. Tightening torque, test frequencies, height and axial and radial force, permissible friction torque and theoretical r
9、unning time for 90% fatigue life probability and the ratio between PU = 90% running time and PU = 10% running time are to be taken from the drawing specification. The bearings have passed the test when none of the following complaints occur during the durability test: a) malfunction b) hard action o
10、r blocking c) bad noise d) stick-slip effect The test must be conducted with at least 8 samples from one supplier and one batch. Fig. 1 shows a section of the strut mount bearing test stand Air actuator for radial force Specimen (concealed) Air actuator for axial force EDS-T-2517BEARINGS FOR STRUT MOUNTS PAGE: 3/3 ISSUED DATE: 1996. 07. 10 REVISED DATE: 2008. 10. 23 VERSION: 3 GM DAEWOO Auto & Technology Fig. 2 is an overall view of the test stand including the pneumatic and electrical control unit Feeding device to induce the steering movement
