Char-Lynn Motor Failure Analysis PDF

Char-Lynn Motor Failure Analysis 1 Slide 1 Drive Wear OK to use again Normal The teeth and finished surface of the drive show no signs of wear, nicks, burrs or scratches. The critical areas to inspect...

Char-Lynn Motor Failure Analysis 1 Slide 1 Drive Wear OK to use again Normal The teeth and finished surface of the drive show no signs of wear, nicks, burrs or scratches. The critical areas to inspect are the gear teeth and ends of the drive. Slide 2 Chipped Do not use again Chipped, damaged gear teeth. The wear is probably caused because of lack of lubrication. Slide 3 Wear Do not use again Gear tooth wear The lines on the face of the drive are normal machining marks and don’t cause any problem for the drive. There is excessive wear on one side of the gear teeth indicating it was ran in only one direction. The chipping was probably caused by lack of lubrication or poor fluid viscosity. The burning mark on the face of the drive is called burnishing, this can happen if the driv moves forward, the forward movemen can be caused by drive tooth wear. 2 Slide 4 Burnishing Do not use again Severe gear teeth wear and burnishing. This shows signs of severe chipping which was probably caused by lack of lubrication or poor fluid viscosity. The burnishing was probably a result of the severe wear on the gear teeth which allows the drive to move forward. Slide 5 Wear Do not use again Gear tooth crown wear The corner of the crown is worn indicating there was corner loading. The corner loading can be caused by excessive wear or lack of lubrication. 3 Slide 6 Drive Spline Wear OK to use again The critical surface areas as shown here on this drive is smooth, free of any nicks, burrs and scratches. This shows very light signs of wear and could be used again. Slide 7 Wear Do not use again Light wear on the gear teeth and chipping on the corners of the drive. The rust stain is on the shaft of the drive and not on the gear teeth which means it should not cause a problem, however, it is an indication water was present in the fluid. The wear in the middle of the gear teeth doesn’t appear to be enough to cause poor performance, however, the chipping on the corners indicate corner loading. This could mean the motor was under a heavy load. Slide 8 Wear Do not use again Crown wear This drive shows signs of wear on the crown of the drive which was probably caused by lack of lubrication. The marks on the top of the drive are machining marks and are probably caused by bad tooling. There is no contact on the top of splines so this in not a problem. 4 Slide 9 Wear Do not use again Gear tooth Wear This is caused by normal wear, probably because of lack of lubrication or poor fluid viscosity. Slide 10 Wear Do not use again Gear tooth Wear This is normal wear, probably caused by lack of lubrication or poor fluid viscosity. Slide 11 Wear Do not use again Severe Gear tooth Wear Normally wear caused by lack of lubrication or improper fluid Viscosity.. 5 Slide 12 Wear & Chipping Do not use again Severe wear Improper run in or start up. It’s best to run in a new motor at low pressure, flow and torque for a period of time. That information is in our catalogs. To assure best motor life, run motor for approximately one hour at 30% of rated pressure before application to full load. Be sure motor is filled with fluid prior to any load applications Slide 13 Wear Do not use again Severe wear Severe wear caused by lack of lubrication or poor fluid viscosity. Slide 14 Wear Do not use again Severe wear Normal wear in the center of the drive. Probably caused by lack of lubrication. 6 Slide 15 Spool Valve ok to use again The critical surface area as shown here on this output shaft is smooth, flat and free of any scratches. No defect is shown. The seal and bearing areas show no sign of wear.. Slide 16 Scored Do not use again Trust loading. Excessive outward thrust loading of the output shaft could create this condition by forcing the shaft into the thrust bearing. Excessive case pressure or back pressure can cause this type of wear. Slide 17 Scored Do not use again Uneven wear between the top of the shaft and bottom of the shaft could be caused by side loading. The scratching and wear marks on the shaft are caused by contamination. There is also wear in the shaft seal area. 7 Slide 18 Scored Do not use again Shaft Seal and Bearing Journal Wear Wear in seal area and bearing area is caused by contamination. This usually indicates the motor was operated with abrasive contamination suspended in the hydraulic fluid. The scratches and grooves as shown on the bearing journal indicates the motor was operated with possible lack of/or improper lubrication and abrasive contamination suspended in the hydraulic fluid. Slide 19 Scored Do not use again Wear in the needle bearing area is caused by contamination. The shaft also shows signs of severe wear which is also caused by contamination. 8 Slide 20 Smeared Do not use again Smearing or wear as shown on the output part of the shaft but not on the bottom of the shaft indicates side loading. This could be caused by a pulley or chain drive that is too tight. Slide 21 Galled Do not use again Severe wear in the seal area and face of the shaft which is caused by contamination. There is more wear on output end of the shaft surface then at the top of the shaft indicating possible side loading. Slide 22 Galling Do not use again The damage on the needle bearing side of the shaft indicates thrust load, pulling force, high case pressure or high back pressure could cause this. 9 Slide 23 Scored Do not use again Severe wear The wear is even and caused by contamination. Slide 24 Scored, Smeared Do not use again The damaged key way is generally caused by improper cup link fit. The scoring noted by the fine scratches around this output shaft seal area and bearing area usually indicates the motor was operated with abrasive contamination suspended in the hydraulic fluid. Slide 25 Galled Do not use again Severe wear The galling as shown is noted by the material removal or grooves around this output shaft. This indicates the motror was operated with possible lack of/or improper lubrication and abrasive contamination suspended in the hydraulic fluid. 10 Slide 26 Galled Do not use again Galling is usually an indication that there was a presence of material that has been removed from one surface, normally caused by friction and adhered to its mating component surface. The galling noted around the shaft indicates it was subjected to a lack of/ or insufficient lubrication. This could have also been caused by high back pressure or thrust loading which could causes heat to up in the bearing area. Slide 27 Scored Do not use again Seal wear The scoring is shown by the fine scratches around this output shaft seal area. This usually indicates the motor was operated with abrasive contamination around the shaft seal and possibly suspended in the hydraulic fluid. Slide 28 Galled Do not use again Inward Thrust Load The galling shown around the output shaft is usually caused by external forces pushing the shaft inward toward the housing. It could also be a sign that there was a lack of or improper lubrication. 11 Slide 29 Scoring Do not use again Burr or contamination The lines on the end cap are caused by a burrs on the running surface of the Gerotor or Geroler star. The could also be caused by contamination suspended in the hydraulic fluid. Slide 30 Disc Valve Ok to use again No signs of wear on the surface. The critical surface area on the running surface, and spline contact area is and free of any nicks, burrs and scratches. Slide 31 Scoring Do not use again The disc valve surface can become scored due to a number of factors, including contamination. There is on notable sign of wear on the drive spline area but there is signs of scoring around the face of the valve indicating abrasive wear was suspending in the hydraulic fluid. 12 Slide 32 Scored Do Not Use Again The scoring marks noted on this disc valve surface indicates it was subject to an abrasive contamination condition. This contamination most likely was suspended in the system high pressure hydraulic fluid or possibly was intro-duced from the unit case hydraulic fluid. Slide 33 Disc Valve Ok to use again No signs of wear on the surface. The critical surface area on this disc valve is free of any nicks, burrs and scratches. Slide 34 Wear Do Not Use Again The wear pattern noted around the surface of this disc valve indicates that it possibly was subject to some very fine abrasive contamination. This contamination may have been suspended in the unit case hydraulic fluid. 13 Slide 35 Wear Chipping in the valve drive area There is excessive wear on one side of the valve drive teeth area indicating it was ran in only one direction. The chipping was probably caused by lack of lubrication or poor fluid viscosity. It could have happened because of lack of lubrication on start up. Wear on the drive area affects timing which allows some of the hydraulic fluid to cross port from the high pressure side to the low pressure side causing poor performance. Slide 36 Valve Drive OK to Use Again The disc motor valve drive surfaces shown here is smooth, flat, and free of any nicks, burrs, and scratches. The critical area is the gear splines and they show no sign of wear or damage. Slide 37 OK to use again The teeth and finished surface of the drive show no signs of wear, nicks, burrs or scratches. The critical areas to inspect are the gear teeth and ends of the drive. 14 Slide 38 Bearing OK to Use Again The shaft bearing mating surfaces as shown here is free of any nicks, burrs or scratches. Slide 39 Spalling Do not use again This bearing shows signs of Spalling which is the damage of the running surfaces and subsequent removal of small particles of material. It is progressive and will spread as a result of continued operation. Contamination is the leading cause of hydraulic component failure which includes bearings. Slide 40 Output Shaft Keyway Chipping No not use again The severe wear (chipping) noted on the coupling end of this shaft indicates an improper fit of its mating coupling. This condition usually is the result of a loose mating coupling. 15 Slide 41 Gerotor or Geroler Smeared and Erosion (pitting) Do Not Use Again The smearing noted across this Geroler star face and roller ends indicates that is was subject to a possible lack of/or improper lubrication. This condition usually is the result of insufficient hydraulic fluid film thickness required to properly lubricate mating component part surfaces. An overrunning load condition could cause this type of condition. An overrunning condition is caused when the hydraulic motor turns so fast it begins to suck fluid faster then the pump can send fluid into it, the motor sends out fluid so fast it causes the pump to turn into a hydraulic motor. The pitting or erosion indicates the motor cavitated which means it was not receiving fluid in sufficient to make up for the need. Slide 42 Scoring Wear in Gerolor roller area is caused by contamination. This usually indicates the motor was operated with abrasive contamination suspended in the hydraulic fluid. The scratches and grooves indicate the motor was operated with possible lack of/or improper lubrication and abrasive contamination suspended in the hydraulic fluid. This kind of damage could also be caused by an overrunning load. 16 Slide 43 Erosion (pitting) Do not use again The erosion (pitting) noted on this valve plate indicates the motor cavitated. It is generally caused by an overrunning load. Cavitation occurs in motors when the motor turns so fast fluid can’t enter the motor in sufficient quantities to make up for the need. Vapor bubbles form due to excessively low inlet pressure (an excessive vacuum) for the fluid being used. The bubbles collapse violently at the outlet causing component erosion and heat. Slide 44 Scoring & Erosion (pitting) Do not use again Erosion noted on the valve plate where the Geroler rolls contacted the valve plate indicate the failure was due an overrunning load condition. The scoring marks noted on this valve plate may have been caused by shifting the motor back and forth too fast. 17 Slide 45 Galling Overrunning load. The galling, chipping and scoring indicate the motor may have been shifting back and forth too fast. It’s also possible the Geroler star was warn causing it to move back and forth causing the wear. 18