All Member Open Forum

Hello everyone,

Hoping to get some thoughts/suggestions on two recent failures I've investigated. Both are electric motors that failed due to oil ingression - in both cases, the motor was C-face mounted to a gear reducer and the reducer output shaft seal failed allowing oil to leak into the motor. Operating context is packaging conveyors, running indoors, unconditioned environment. Small motors with "lubed-for-life" gear reducers (no oil level ports). Regular visual, temperature, and vibration inspections are already being performed.

Here is where I am getting hung up on determining an effective way of dealing with the failure mode - based on the information I have from my technicians, in both cases there were:

• no external signs of an oil leak
• no noticeable change in temperature or vibration readings on motor/reducer

The lack of temperature/vibration response is confusing to me - has anyone else dealt with this before and found an effective way to monitor the seal condition and/or detect a leak? Hoping I'm overlooking an obvious solution.

Hello everyone,

Hoping to get some thoughts/suggestions on two recent failures I've investigated. Both are electric motors that failed due to oil ingression - in both cases, the motor was C-face mounted to a gear reducer and the reducer output shaft seal failed allowing oil to leak into the motor. Operating context is packaging conveyors, running indoors, unconditioned environment. Small motors with "lubed-for-life" gear reducers (no oil level ports). Regular visual, temperature, and vibration inspections are already being performed.

Here is where I am getting hung up on determining an effective way of dealing with the failure mode - based on the information I have from my technicians, in both cases there were:

• no external signs of an oil leak
• no noticeable change in temperature or vibration readings on motor/reducer

The lack of temperature/vibration response is confusing to me - has anyone else dealt with this before and found an effective way to monitor the seal condition and/or detect a leak? Hoping I'm overlooking an obvious solution.

Hello everyone,

Hoping to get some thoughts/suggestions on two recent failures I've investigated. Both are electric motors that failed due to oil ingression - in both cases, the motor was C-face mounted to a gear reducer and the reducer output shaft seal failed allowing oil to leak into the motor. Operating context is packaging conveyors, running indoors, unconditioned environment. Small motors with "lubed-for-life" gear reducers (no oil level ports). Regular visual, temperature, and vibration inspections are already being performed.

Here is where I am getting hung up on determining an effective way of dealing with the failure mode - based on the information I have from my technicians, in both cases there were:

• no external signs of an oil leak
• no noticeable change in temperature or vibration readings on motor/reducer

The lack of temperature/vibration response is confusing to me - has anyone else dealt with this before and found an effective way to monitor the seal condition and/or detect a leak? Hoping I'm overlooking an obvious solution.

I have seen this failure mode quite often in conveyor application and it is very challenging to detect the leak or monitor the seal condition as it is all internal component. A deeper vibration analysis could detect it  but it would need a detailed trend and a carefully filtered resonance.

Few things that could potentially cause the problem that you might want to look into if not done already.

1. Motor install orientation ( Breather/weep hole)

• All motors generally have a breather/weep hole that prevent any accumulation of condensate inside the enclosure. By doing so, the breather allow the motor to let air in and out and if it is plugged it could cause seal's premature failure.
• The location of the breather or weep hole depends on the orientation of the motor ( Vertical vs Horizontal ) . On the vertical mount , it is impossible to detect the leak; the oil will drip down the motor and by the time it leaks out at the end , it is too late. On Some Horizontal mount, you might be able to detect the leak early.

       2. Motor install ( Shaft alignment)

             Is the Shaft align properly to prevent any axial movement ?

        3. A motor circuit anlalyzer can help you diagnoze the winding of the motor when it is indeed contaminated with oil and it has very good timing from failure detection to catastrophic failure ( 4 months to one 1 year in some cases). 

Hello everyone,

Hoping to get some thoughts/suggestions on two recent failures I've investigated. Both are electric motors that failed due to oil ingression - in both cases, the motor was C-face mounted to a gear reducer and the reducer output shaft seal failed allowing oil to leak into the motor. Operating context is packaging conveyors, running indoors, unconditioned environment. Small motors with "lubed-for-life" gear reducers (no oil level ports). Regular visual, temperature, and vibration inspections are already being performed.

Here is where I am getting hung up on determining an effective way of dealing with the failure mode - based on the information I have from my technicians, in both cases there were:

• no external signs of an oil leak
• no noticeable change in temperature or vibration readings on motor/reducer

The lack of temperature/vibration response is confusing to me - has anyone else dealt with this before and found an effective way to monitor the seal condition and/or detect a leak? Hoping I'm overlooking an obvious solution.

Hello everyone,

Hoping to get some thoughts/suggestions on two recent failures I've investigated. Both are electric motors that failed due to oil ingression - in both cases, the motor was C-face mounted to a gear reducer and the reducer output shaft seal failed allowing oil to leak into the motor. Operating context is packaging conveyors, running indoors, unconditioned environment. Small motors with "lubed-for-life" gear reducers (no oil level ports). Regular visual, temperature, and vibration inspections are already being performed.

Here is where I am getting hung up on determining an effective way of dealing with the failure mode - based on the information I have from my technicians, in both cases there were:

• no external signs of an oil leak
• no noticeable change in temperature or vibration readings on motor/reducer

The lack of temperature/vibration response is confusing to me - has anyone else dealt with this before and found an effective way to monitor the seal condition and/or detect a leak? Hoping I'm overlooking an obvious solution.

Thanks for the responses so far - I'm going to try to address all the questions in one post so apologies if this gets long.

There have been two failures in the last month - one the motor was about 1 year in-service, reducer about four years; on the other failure the components were in service about seven years. Anecdotally I have seen four or five of these failures a year, all in the same packaging/conveying section. Motor and reducer manufacturers vary, but the orientation/mounting arrangement and drive type (timing belt) is the same.

Howard, since these are "lubed for life" reducers I hadn't considered the seal/lubricant compatibility but it is probably worth a look. As far as assembly goes, I was wondering if uneven or improper torque on the C-face bolts would contribute to premature seal failure?

Rick, the motors are rated for the orientation and mounting. The gearbox mounting will vary - based on the photos I attached maybe you can tell me whether what you are describing needs to be investigated further.

Cheick, I'm glad you mentioned MCA - the motors are smaller and a lower criticality than what I would typically apply that to, but I had thought about that as a way to detect contamination if other prevention/detection isn't effective. What would you recommend for an initial test frequency?

I have attached some photos showing the failed components on the most recent failure and a couple photos of the application on the last two.

Hello everyone,

Hoping to get some thoughts/suggestions on two recent failures I've investigated. Both are electric motors that failed due to oil ingression - in both cases, the motor was C-face mounted to a gear reducer and the reducer output shaft seal failed allowing oil to leak into the motor. Operating context is packaging conveyors, running indoors, unconditioned environment. Small motors with "lubed-for-life" gear reducers (no oil level ports). Regular visual, temperature, and vibration inspections are already being performed.

Here is where I am getting hung up on determining an effective way of dealing with the failure mode - based on the information I have from my technicians, in both cases there were:

• no external signs of an oil leak
• no noticeable change in temperature or vibration readings on motor/reducer

The lack of temperature/vibration response is confusing to me - has anyone else dealt with this before and found an effective way to monitor the seal condition and/or detect a leak? Hoping I'm overlooking an obvious solution.

Thanks for the responses so far - I'm going to try to address all the questions in one post so apologies if this gets long.

There have been two failures in the last month - one the motor was about 1 year in-service, reducer about four years; on the other failure the components were in service about seven years. Anecdotally I have seen four or five of these failures a year, all in the same packaging/conveying section. Motor and reducer manufacturers vary, but the orientation/mounting arrangement and drive type (timing belt) is the same.

Howard, since these are "lubed for life" reducers I hadn't considered the seal/lubricant compatibility but it is probably worth a look. As far as assembly goes, I was wondering if uneven or improper torque on the C-face bolts would contribute to premature seal failure?

Rick, the motors are rated for the orientation and mounting. The gearbox mounting will vary - based on the photos I attached maybe you can tell me whether what you are describing needs to be investigated further.

Cheick, I'm glad you mentioned MCA - the motors are smaller and a lower criticality than what I would typically apply that to, but I had thought about that as a way to detect contamination if other prevention/detection isn't effective. What would you recommend for an initial test frequency?

I have attached some photos showing the failed components on the most recent failure and a couple photos of the application on the last two.

Hello everyone,

Hoping to get some thoughts/suggestions on two recent failures I've investigated. Both are electric motors that failed due to oil ingression - in both cases, the motor was C-face mounted to a gear reducer and the reducer output shaft seal failed allowing oil to leak into the motor. Operating context is packaging conveyors, running indoors, unconditioned environment. Small motors with "lubed-for-life" gear reducers (no oil level ports). Regular visual, temperature, and vibration inspections are already being performed.

Here is where I am getting hung up on determining an effective way of dealing with the failure mode - based on the information I have from my technicians, in both cases there were:

• no external signs of an oil leak
• no noticeable change in temperature or vibration readings on motor/reducer

The lack of temperature/vibration response is confusing to me - has anyone else dealt with this before and found an effective way to monitor the seal condition and/or detect a leak? Hoping I'm overlooking an obvious solution.

Thanks for the responses so far - I'm going to try to address all the questions in one post so apologies if this gets long.

There have been two failures in the last month - one the motor was about 1 year in-service, reducer about four years; on the other failure the components were in service about seven years. Anecdotally I have seen four or five of these failures a year, all in the same packaging/conveying section. Motor and reducer manufacturers vary, but the orientation/mounting arrangement and drive type (timing belt) is the same.

Howard, since these are "lubed for life" reducers I hadn't considered the seal/lubricant compatibility but it is probably worth a look. As far as assembly goes, I was wondering if uneven or improper torque on the C-face bolts would contribute to premature seal failure?

Rick, the motors are rated for the orientation and mounting. The gearbox mounting will vary - based on the photos I attached maybe you can tell me whether what you are describing needs to be investigated further.

Cheick, I'm glad you mentioned MCA - the motors are smaller and a lower criticality than what I would typically apply that to, but I had thought about that as a way to detect contamination if other prevention/detection isn't effective. What would you recommend for an initial test frequency?

I have attached some photos showing the failed components on the most recent failure and a couple photos of the application on the last two.

Hello everyone,

Hoping to get some thoughts/suggestions on two recent failures I've investigated. Both are electric motors that failed due to oil ingression - in both cases, the motor was C-face mounted to a gear reducer and the reducer output shaft seal failed allowing oil to leak into the motor. Operating context is packaging conveyors, running indoors, unconditioned environment. Small motors with "lubed-for-life" gear reducers (no oil level ports). Regular visual, temperature, and vibration inspections are already being performed.

Here is where I am getting hung up on determining an effective way of dealing with the failure mode - based on the information I have from my technicians, in both cases there were:

• no external signs of an oil leak
• no noticeable change in temperature or vibration readings on motor/reducer

The lack of temperature/vibration response is confusing to me - has anyone else dealt with this before and found an effective way to monitor the seal condition and/or detect a leak? Hoping I'm overlooking an obvious solution.