Download Reduce setup time for torque stand

Lightnin SPX
High Torque Test Stand
Aditya
-
Oriana - Don
-
Jesse - Ron
05413
-
Dana
-
Geoff
Team Members

Aditya Sanghi, IE - Project Leader

Dana Harris, IE
Ron Mendolera, EE
Jesse Warner, EE

Dr. William Scarbrough,
Project Coordinator






5
Geoff Cusano, ME
Oriana Starr, ME
Don Strong, ME
Dr. Alan Nye,
Mentor
Project
Project Overview





Sponsor: Lightnin SPX
Manufacture pumps, mixers, etc.
Gear reducer production moved to
Rochester, NY from Wytheville, VA
Evaluate final assembly & testing processes
Identify & solve inefficiencies
6
700/800 Series Overview



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Sizes
Configurations
Hollow & Solid shafts
Weight
Assembly process
Mixer
Gear Reducer
7
Assembly Stand
Side
Front
8
Assembly Rotation
Rotated 90° - back
Rotated 90° - front
9
Spin Test & Assembly Area
10
Torque Stand
Front
Side
11
Project Mission Statement

Identify and eliminate process inefficiencies



Propose process flow improvements
Adhere to constraints


Redesign & relocate the torque test stand
time, cost, footprint & height
Avoid hazardous workstations
12
Initial Improvement Ideas

Obvious

Reduce long travel distance to torque test


Reduce travel time between stands


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Fork truck
Crane
Fork truck
“Homerun”  3-in-1 stand

Assembly, spin test, torque test
13
Time Studies - Plan

Identified largest areas for improvement
1) Torque test stand setup: 135 min
2) Spin Test Stand setup: 25 min
3) Walk time during large assembly: 20 min
4) Transportation to torque test : 12 min

Justify discontinuing development of 3-in-1 concept

Torque test stand setup: examine further
14
Eliminate 3-in-1 Concept

Impossible to meet yearly production volume



Projected costs were prohibitive
Much more risk




497 min. of build time per reducer, only 1 stand
Brand new, unique design
If the all-in-one stand breaks down, entire process halted
Customer visits interrupt production
Can only build one unit at a time
15
Input from Lightnin

Meeting with Management: December 2004





100% torque testing – Warranty issues
Remove waste
Relocate torque stand – reclaim dock
Ultimately: accomplish torque AND spin test in the
time it currently takes just to spin
This would further encourage 100% torque testing
16
Final Improvement Ideas

Perform spin test on torque stand

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Reduce setup time for torque stand

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

Eliminate spin test stand & transport time
Adjustable input motor
Universalized couplers with splines
Oil tanks with heater
Simplified operator controls
Reunite small & large assembly areas
17
Final Design Concept



Current large assembly
area
Use current assembly stand
Redesign the torque test
stand




Reduce height & footprint
Torque AND spin test
capacity
Make the process more
efficient
Standardize controls: direct
labor NOT technician
18
CURRENT

Align shafts: motor output to reducer input



Measure, bolt
Heat the oils


Bolt input shaft
Couple the reducer’s output shaft to the slave unit


Manually adjust reducer height
Spacer plates
Adjust distance: motor output to reducer input


Torque Test Stand Setup
Cannot begin until setup is complete
Manually adjust air pressure regulator for torque
control
19
NEW

Torque Test Stand Setup
Align shafts: motor output to reducer input
Automatically adjust input motor height
 Universal mounting plate
 Scissor lift with elevation control
Adjust distance: motor output to reducer input
 Rail, keyed couples
Couple the reducer’s output shaft to the slave unit
 Splined couples
Heat the oils
 Can begin before the reducer is craned onto the stand
 Automatic electronic control
Adjust air pressure regulator for torque control
 Automatic electronic control

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


20
Inline Input Motor


Same arrangement as current
Components
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25 HP motor
40:1 Reducer
Clutch
60 HP motor
Torque Sensor
Existing Mount
21
Horizontal Movement

Function


Profile Rail
Guides
Rails

Specs



SKF
Allow input motor
assembly to slide
accommodate 8 different
input configurations
Weight Capacity
Moment Capacity
UNI-LIFT
Actuator

M1
Specs

Linear Actuator
Overcome Friction
Forces
22
Vertical Movement

Function


Allow input motor
assembly to adjust to 8
different input heights
Hydraulic Lift

Specs




Weight Capacity
Transverse Load Capacity
3’ X 7’ Platform
Mounting Substructure
23
LK Goodwin
Tandem Hydraulic Lift
Input Couple

Function


Connects Input Motor to
Input Shaft of Testing
Reducer
Improvements


Two Keyways reduces
alignment.
No Bolting reduces
setup time.
24
Output Couple

Function


Connect output shaft of
tested reducer to slave
Design

Time Savings



Indexing
No Height Adjustments
Specs

800 Series Spline
700 Series Spline
Universal Female
Female Spline
25
Coupling Analysis

Stress Analysis

782/882 Coupling

Tmax = 310,000 in-lb
ssy  .577s y Shear Strength
 all  .75ssy Allowable Shear Stress
 K
Tr

2
 K

32
Unit
780/880
781/881
782/882
783/883
ID
(in)
2.125
2.250
2.750
3.500
Shear Stress Solid Shaf
D4
Tr
Shear Stress Hollow Shaft
(D4  d 4 )
OD
(in)
3.175
3.300
4.000
4.900
T
(in - lb)
10620
14160
21500
18010
Kd 2
Kt3
Km4
1.05
1
1.2
1.3
5.20
5.20
5.20
5.20
1.2
1.2
1.2
1.2

F.S.
(psi)
9271
3.8
10892
3.2
11342
3.1
6107
5.7
26
Fatigue Analysis
 
N  
a
Se  Se' KaKbKcKe
0.9 S ut
a
Se
Fatigue Failure Analysis:
Surface Factor
1
b
2
2
0.9 S ut
1
b  log(
)
3
Se
Size Factor
Machined Surface
a
b
Ka
2.7
-0.265
0.81
Kb
Load Factor
0.75
For d > 2" In Torsion
Stress Concentration
For Torsion
Kc
0.577
Ke
1
Stress Concentrations taken into account in Stress Anylysis
Sut
Se'
Se
a
b
95
kpsi
47.88
kpsi
16.73625 kpsi
436.7913
-0.2361
Minimum Tensile Strength
Unit
Endurance Limit =.504Sut
780/880
781/881
782/882
783/883
1. Number of Cycles in millions of cycles
27
load
(kpsi)
9
11
11
6
N1
12
6
5
72
# of Test
in life
4
2
2
24
Spline Development

o
30 Flat root profile
Size restriction
6/12 Pitch



Analysis
Ss 
S2 
16TDre K a
Sh 
 Dre4  Dh4 K f

Sp 
Sc 
4TK a K m
DNLetK f
2TK m K a
9 DNLe hK f
T tan 
S1 
Dt w L


1.656  rpm  Doi2  0.212 Dri2
2
16TK a
Dre3 K f
S3 
Stress

1000000
St 
4T
D 2 LeY
K a K m S1  S3   S2 
Factor of
Safety
Calculated Allowable *
Kf
Description
Ss1
2035.0
20000
psi
9.83
Shear Stress under root of external tooth of solid shaft
Sh
1
2918.0
20000
psi
6.85
Shear Stress under root of external tooth of hollow shaft
Sp
1
5239.7
20000
psi
3.82
Shear Stress at Pitch Diameter of Tooth
Sc2
301.6
1500
psi
4.97
Compressive Stress on side of Spline
St3
7049.1
22000
psi
3.12
Bursting Stress on Spline
28
Overall Structure

Function


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Support loads
Set height for slave and
new couplers
Universal mounting plate
Actuator mount
Design


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Two tier design
Footprint: 9’ x 19’
Clearance
29
Stand Analysis

Member Analysis

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Critical members
Size Recommendations
Mount Requirements
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Actuator Assembly
Universal Plate
Loads


Weights
Output Torque
30
Controls


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Oil temperatures
Elevation of input motor
Torque
31
Oil Temperature Control




Heat oils up to operating
temperature before test unit is
place on stand
Tanks are insulated and
temperature-controlled
80-gallon tank for lube oil
50-gallon tank for brake
transmission oil
32
Elevation Control

Eliminates the need to make manual height
adjustments with spacer plates.

Uses a programmed PLC with a position
sensor in the feedback loop to control the
hydraulic pump motor.
33
Elevation Control Algorithm
Select Model:
1) 750/880
2) 781/881
3) 782/882
4) 783/883
Select Reduction:
A) Double
B) Triple
Position Sensor
D/A Conversion
Input:
Output:
1A
0V
1B
3.363V
2A
.457V
2B
4.521V
3A
1.219V
3B
5.903V
4A
2.474V
4B
7.838V
X
Y
Compare
Y, X
Y<X
Position
Sensor
(20mV/mm)
Close
Relay
Hydraulic
Pump
Motor
Position
Y >= X
Open
Relay
Model
780/880
780/880
781/881
781/881
782/882
782/882
783/883
783/883
Reduction
Double
Triple
Double
Triple
Double
Triple
Double
Triple
Height relative to 780/880 Position sensor output
double reduction (mm)
voltage at this height (V)
0.00
0.000
168.00
3.363
22.86
0.457
226.06
4.521
60.96
1.219
295.15
5.903
123.70
2.474
391.90
7.838
D/A Conversion Table
34
Torque Control

Eliminates the need to make manual adjustments
of air pressure regulator to control brake pressure
which determines torque.

Uses a programmed PLC with a torque sensor in
the feedback loop to control an electronic air
pressure regulator.
35
Torque Control Algorithm
Operator
Personnel
Start
Start/Stop
Process
Stop
Digital Input of
Desired Torque.
Enter
D/A Conversion
(250 uV/in. lb)
X
0V
Compare
Y, X
Electronic Air Pressure Regulator
Y=X
Y>X
Y<X
Y
Increase
85mV
Decrease
85mV
No Change
Voltage
Source
Torque Sensor
250 uA/in.lb
V1
V1 > 5.3
Compare V1, 5.3V
(~65 psi)
V1 < 5.3
Voltage-Controlled Air Pressure
Regulator (85.5 mV/psi)
Pneumatic-Controlled Brake
Torque Sensor
Applied Torque
36
Initialize to
0V
(3 psi)
Electronic Database


Eliminates the need to search through hard
copies for previous test data.
Visual basic used to create a user-friendly
Microsoft Access database
37
Old vs. New Process Comparison

Estimated time saved: over 1.5 hours!
Old
Equipment
Times
(min)
New
Equipment
Times
(min)
Time Saved
(min)
Height
Spacer plates
16
Adjustable lift
0.50
7.50
Distance
Flanged input
shaft
10
Rail & couple
6.25
11.75
Couple
Flanged
couples
21
Spline
0.33
20.67
Oil
After setup
60
During setup
0.50
59.50
7.58
99.42
Task
107
38
Final Layout Options
Two locations



Current large assembly
“Back bay” area
Options

1)
2)
Just replace spin stand with torque stand
Move ALL final assembly operations to the back
bay area
39
Layout Option 1



Easiest to implement, less change
Rearrange assembly stand
Still have wasted transport time from having
small & large assembly separated
40
Current Large Assembly
41
Redesigned Large Assembly
42
Layout Option 2





Requires greater willingness to change
Move all to back bay, reunites small & large
assembly areas, eliminates wasted transportation
time
Slight downtime, but current production
volumes/build times indicate that it could be done
during off-times without delaying shipments
More room to work, both for reducer assembly, and
the areas near current large assembly
Flow
43
Back Bay Layout
44
Simulation


Results of simulation, given the new design
Greatly reduced torque test time, not enough
to accomplish ultimate goal


Still takes 20-30 minutes longer to do torque &
spin vs. just spin
May still be worthwhile to implement the
design


Reclaim dock, improve flow, save time
Future Lean activities may make up the remaining
time

Standardization, kaizen, etc.
45
Cost of Implementation

BOM

Cost to Build the stand - $10,000
Sum total = 35,368

46
Incremental Revenue/Savings

Incremental Revenues



Revenue by selling extra torque testing as a
service (20 units @ $2k/unit)
Revenue by marketing selling extra units due to
improved reliability (10@$30k)
Incremental Savings



Warranty Costs saved due to the 100% testing
(25k in Yr2 and 50k thereafter)
Labor Savings (3 hrs @$75/hr /torque tested unit)
Moving from the shipping dock ($10/sq ft)
47
Final Recommendations


Build stand
Lean, kaizen, process improvements
activities
“It is very difficult early on to turn the flywheel of
improvement, especially from a dead stop, or
worse yet a negative rotation.”
Good to Great by Jim Collins
48
Acknowledgments








SPX Process Equipment, Lightnin Division
Dave Engel, Lightnin SPX
Al Aponte, Lightnin SPX
Jeff Flint, Lightnin SPX
Production staff at Lightnin
Dr. Hany Ghoneim, ME Department
Dr. Elizabeth DeBartolo, ME Department
Bob Thomas, Rochester Gear
49
Questions
?
Initial Concept Development

Transportation


Slave unit


Rail system, wheels, rotary arm, trolley, etc.
Pump, two gears, electric generator, etc.
Attachment of test unit to stand

Clamps, magnets, pins, bolts, etc.
51
Needs Assessment

Order Qualifiers & Winners






Cost to build SHALL NOT exceed $200,000
Return On Investment
Labor savings
Design software to be compatible with Autodesk
Inventor
Utilize existing equipment
Scope
52
Simulation Model
Proposed
Option 1
Proposed
Option 2
Value added
time
Non Value added
Other
Transfer
Wait
Total
Value added
time
Non Value added
Other
Transfer
Wait
Total
780
781
782
783
221.97
26.91
25.47
6.47
384.32
665.15
223.83
27.23
25.92
6.49
400.74
684.23
230.3
40.27
43.08
5.66
427.22
746.54
222.85
40.84
40.52
5.27
398.36
707.86
780
781
782
783
297.49
33.98
0
12.03
452.3
795.81
297.57
33.99
0
11.97
464.8
808.33
304.19
28.95
4
14.04
469.68
820.86
303.29
29.1
3.97
13.81
503.56
853.73
780
781
782
783
297.29
34.03
0
11.02
442.61
784.96
297.49
34.03
0
11.01
460.97
803.51
303.63
29.04
0
10.97
473.1
816.75
304.5
28.91
0
10.98
473.68
818.07
Compare total times across all options
Tota Time (Min)
Current
Value added
time
Non Value added
Other
Transfer
Wait
Total
900
800
700
600
500
400
300
200
100
0
Current
Option 1
Option 2
780
781
782
Reducer Type
53
783
Slave & Braking

Reuse current slave,



Replacements small enough didn’t meet spec
Reduce cost of project
Current brake


Works well
Reduce cost
54
Process Flow
Torque
Test
Assembly
Stand
100%
20%
Distance ~ 500 ft
20%
Spin
Test
80%
55
Shipping
Initial Concept Development

Level 0: Station Setup Options
Three Stations
Two Stations
One Station
56