DQ03DR090 High Pressure Coolant Pump Failure

VQ Crankshaft Machining

Concerns• 6 failures/yr = $47,484.00 in pump

replacement costs

• 72 hours production loss / 216 man hours of maintenance labor during the last year Sumitomo was used.

• 12 month average rate of failure was 1 pump every 2 months.

• Excessive motor / pump noise.

Inadequate Filtration

MaterialMan

MethodMachine

Tight Tolerance Pump

Pump

Failure

Filter Changes Coolant Type

FTL Type Operation

Coolant Temperature

Cause & Effect Diagram:

Filter Replacement Frequency

Why #1 Why did we have pump failures?

• The coolant system was filtered to 25 microns and used a non-repairable Sumitomo Gear Pump.

• Due to the tight tolerance of the gear pump Sumitomo suggested 10 micron filtration to guarantee long-term reliability.

Why #2?Why didn’t we replace the 25 micron filters with 10 micron filters?

The flow rate needed for the high pressure system was too large to use 10 micron filters without excessive size and cost increase.

Therefore the only improvement alternative was to replace the pump.

Improvement # 1

• Replace the Sumitomo gear pump with a Knoll screw pump.

Improved reliabilityToyota currently uses Knoll pumps

with zero failures in 5+ years.

Improvement # 2

• Original • New Style

• Motor horsepower reduced from 50hp to 40hp.• Noise reduced by 10+ decibels.• Need for a sound reduction shroud eliminated, reducing the

amount of time to access the motor.

Replace the loud pump motor with a quiet, efficient motor.

Pump Comparison

• Sumitomo requires 10 micron filtration. Filter upgrade required.

• Sumitomo cost $7,914.0

• Sumitomo is non-repairable

• Sumitomo lead time is 60 days

• Knoll is capable of handling contamination up to 50 microns. No filter upgrades needed.

• Knoll cost $6,924.00

• Knoll is easily repairable.

• Knoll lead time is 48 hours.

• Knoll designed and manufactured a complete drop in assembly for safe/easy installation.

• The cost was $10,700 each for a total initial investment of $21,400.

• At a failure rate of 6 pumps/year the Return On Investment was 2.7 months.

Complete drop in Assembly

Additional benefits of this activity

• $26,084 replacement savings the first year.

• $47,484 each of the following years.

5 year projection

• Replacement cost savings

$216,020

• Labor cost savings

$50,350

Knowledge Sharing

Facts and knowledge of this improvement will be shared with other Nissan Machining Facilities through

Horizontal Deployment via GMR.

Questions / Comments