Excerpt from the report-----------------------------------------------------------------------------------------------------
1.0 ABSTRACT
1.1 Object
Investigation into failures noted by Research International of Motion Systems model 7162-0388 lift actuator.
1.2 Conclusions
Upon completion of the tests no failures of the lift actuators under normal operating conditions were evident.
2.0 UNIT(S) TESTED
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MANUFACTURER: |
Motion Systems Corp. |
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DEVICE: |
Lift Actuator |
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MODEL/PART NO.:
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7162-0388 |
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SERIAL NO.: |
New Unit : 00200, Field Unit: 04695 |
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The results of this test apply only to the units identified in this
Engineering Report by device identifier and model / part number, or serial
number. |
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3.0 TEST REQUESTED
Investigate possible failure methods for two Motion Systems lift actuators model 7162-0388. One new unit and one field service are to be subjected to simulated field operating conditions which include: 1) normal load conditions, 2) overload conditions, 3) overload conditions with non-recommended shaft grease, 4) overload conditions with collar of lift mechanism at elevated temperature.
4.0 INSTRUMENTATION, PROCEDURE AND RESULTS
4.1
Instrumentation
All instrumentation is calibrated regularly by methods directly traceable to the National Institute of Standards and Technology, and in accordance with MIL-STD-45662A, MIL-I-45208A, and ANSI/NCSL Z540-1-1994.
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Equipment Number |
Description |
Manufacturer |
Model No |
Last Calibration |
Due Calibration |
Range |
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740-054 |
Universal Testing Machine |
Instron |
1125 |
8/18/1999 |
8/18/2001 |
0 to 20,000 lbs |
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745-012 |
Load Cell Compression &
Tension |
Instron |
2511-305 |
8/18/1999 |
8/18/2001 |
0 to 20,000 lbs |
4.2
Procedure
The lift actuator units were tested by placing them into a fixture attached to a Instron Universal Testing Machine and applying a compressive load along the actuator axis (Photograph No. 1 - Test Setup of Lift Actuator). The units were tested under dynamic as well as static loading conditions. For this test “dynamic loading” mean that the lift actuator is loaded while the motor is running with the lift mechanism at full extension, while “static loading” refers to loading the lift mechanism at full extension without the lift actuator motor running.
With the Instron software graphs of load vs. displacement were constructed for several different loading conditions. Following is a list of the tests performed on a new lift actuator as well as on a lift actuator that had previously been in field service.
Tests Performed
1) Normal load conditions
The lift actuators are loaded to 1000 lbs dynamically and 3000 lbs statically
2) Overload conditions
a) Lift actuator loaded to maximum load until unit fails (new unit only)
b) Lift actuators loaded to 3000 lbs; both dynamic and static
3) Overload conditions with non-recommended shaft grease (field unit only)
a) Lift actuator operated without grease on lift mechanism
(Grease was removed with acetone)
b) Lift actuators operated with synthetic molly grease
c) Lift actuators operated with silicon grease
d) Lift actuators operated with Teflon grease (heated only)
4) Overload conditions with collar of lift mechanism at elevated temperature and Teflon grease on lift mechanism
a) Lift mechanism heated to 115 F
b) Lift mechanism heated to 140 F
c) Lift mechanism heated to 176 F
4.3 Results
The results of this test are summarized in Table 1. Graphs of each individual test as well as specific test notes are included in the appendix to this report. A test is considered successful (i.e. pass) if the test lift actuator supports the load confronting it without yielding (seen as a sudden decrease in load on the load vs. displacement graph). All of the tests performed on both the new and the old lift actuators were considered successful. In all cases tests were repeated 2 or more times to ensure repeatability.
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Environ Report # 26191-1, "Lift Actuator Compression Test" |
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Table 1: Summary of Test Results |
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Test Description |
Test Name |
Sample Id/File name |
Maximum Load (lbs) |
Pass/Fail |
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NEW MOTOR (serial # 00200) |
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Calibration Test (21 lb load) |
cal 1 |
26191-1 |
21.2 |
Pass |
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3000 lb static load |
new-static_2 |
26191-1 |
3027 |
Pass |
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1000 lb Dynamic Load |
new_dyn_1 |
26191-2 |
1016 |
Pass |
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1000 lb Dynamic Load |
new_dyn_2 |
26191-2 |
1009 |
Pass |
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1000 lb Dynamic Load |
new_dyn_3 |
26191-2 |
1002 |
Pass |
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1000 lb Dynamic Load |
new_dyn_4 |
26191-3 |
1002 |
Pass |
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1000 lb Dynamic Load |
new_dyn_5 |
26191-3 |
1002 |
Pass |
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Max Dynamic Load (5) |
new_dyn_6 |
26191-3 |
7375 |
Pass |
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Max Dynamic Load (5) |
new_dyn_7 |
26191-3 |
8200 |
Pass |
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FIELD SERVICE
MOTOR (serial # 04695) |
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1000 lb Dynamic Load |
old_dyn_1 |
26191-4 |
1009 |
Pass |
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1000 lb Dynamic Load |
old_dyn_2 |
26191-4 |
1002 |
Pass |
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1000 lb Dynamic Load |
old_dyn_3 |
26191-4 |
1002 |
Pass |
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1000 lb Dynamic Load |
old_dyn_4 |
26191-4 |
1002 |
Pass |
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1000 lb Dynamic Load |
old_dyn_5 |
26191-4 |
1002 |
Pass |
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1000 Lb Dynamic Load/ Loose gearbox bolts |
old_bolts_6 |
26191-5 |
1002 |
Pass |
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1000 Lb Dynamic Load/ Loose gearbox bolts |
old_bolts_7 |
26191-5 |
1002 |
Pass |
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1000 Lb Dynamic Load/ Loose gearbox bolts |
old_bolts_8 |
26191-5 |
1002 |
Pass |
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3000 lb Static |
old_sta_9 |
26191-6 |
3006 |
Pass |
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3000 lb Static |
old_sta_10 |
26191-6 |
3006 |
Pass |
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3000 lb Static |
old_sta_11 |
26191-6 |
3006 |
Pass |
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5000 lb Static |
old_sta_12 |
26191-6 |
5003 |
Pass |
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5000 lb Static |
old_sta_13 |
26191-6 |
5003 |
Pass |
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3000 lb Dynamic Load/ no grease |
old_grs_14 |
26191-7 |
3006 |
Pass |
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3000 lb Dynamic Load/ no grease |
old_grs_15 |
26191-7 |
3013 |
Pass? |
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3000 lb Dynamic Load/ no grease |
old_grs_16 |
26191-7 |
3006 |
Pass |
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3000 lb Dynamic Load/ no grease (1) |
old_grs_17 |
26191-7 |
296 |
Pass |
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3000 lb Dynamic Load/ no grease |
old_grs_18 |
26191-7 |
3013 |
Pass |
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3000 lb Dynamic Load/ no grease |
old_grs_19 |
26191-7 |
3006 |
Pass |
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3000 lb Dynamic Load/ no grease |
old_grs_20 |
26191-7 |
3006 |
Pass |
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3000 lb Dynamic Load/ no grease |
old_grs_21 |
26191-7 |
3006 |
Pass |
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3000 lb Dynamic Load/ Molly grease (2) |
old_moly_23 |
26191-8 |
3013 |
Pass |
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3000 lb Dynamic Load/ Molly grease |
old_moly_24 |
26191-8 |
3013 |
Pass |
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3000 lb Dynamic Load/ Molly grease (1) |
old_moly_25 |
26191-8 |
7 |
Pass |
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3000 lb Dynamic Load/ Molly grease |
old_moly_26 |
26191-8 |
3013 |
Pass |
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3000 lb Dynamic Load/ Silicon grease (3) |
old_sili_27 |
26191-9 |
3006 |
Pass |
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3000 lb Dynamic Load/ Silicon grease |
old_sili_28 |
26191-9 |
3006 |
Pass |
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3000 lb Dynamic Load/ Silicon grease |
old_sili_29 |
26191-9 |
3006 |
Pass |
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3000 lb Dynamic/Teflon grease (4) / Heated Collar 115 F |
ht_115_30 |
26191-10 |
3013 |
Pass |
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3000 lb Dynamic/Teflon grease/ Heated Collar 115 F |
ht_115_31 |
26191-10 |
3006 |
Pass |
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3000 lb Dynamic/Teflon grease/ Heated Collar 115 F |
ht_115_32 |
26191-10 |
3013 |
Pass |
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3000 lb Dynamic/ Teflon grease/Heated Collar 140 F |
ht_140_33 |
26191-10 |
3006 |
Pass |
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3000 lb Dynamic/ Teflon grease/Heated Collar 140 F |
ht_140_33 |
26191-10 |
3006 |
Pass |
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3000 lb Dynamic/ Teflon grease/Heated Collar 140 F |
ht_140_33 |
26191-10 |
3006 |
Pass |
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3000 lb Dynamic/ Teflon grease Heated Collar 176 F |
ht_176_36 |
26191-10 |
30013 |
Pass |
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3000 lb Dynamic/ Teflon grease Heated Collar 176 F |
ht_176_37 |
26191-10 |
3006 |
Pass |
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3000 lb Dynamic/ Teflon grease Heated Collar 176 F |
ht_176_38 |
26191-10 |
3006 |
Pass |
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Test Notes |
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1) Test Stopped Before Completion |
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2) Shell Aero Shell synthetic diester molly 17 grease |
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3) 3M Silicon Paste |
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4) Magna Lube-G Teflon Grease |
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5) Tested was stopped because of shaft deflection (not yielding) |
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