systems level design review ul vibration test apparatus january 11, 2013 kgcoe room # 2255...

Systems Level Design ReviewUL Vibration Test Apparatus

January 11, 2013KGCOE Room # 2255

10:00AM-12:00PM Est.

UL Vibration Test Apparatus 2

Project & Team InformationProject: UL Vibration Test ApparatusProject Number: 13471

Customer: Eaton Corporation (previously Cooper Crouse-Hinds Industries)Customer Contact: Joe Manahan

RIT Faculty Guide: Dr. Benjamin Varela

Project Team: Walter BergstromSean CootsSpencer CrandellMark Ellison

January 11, 2013


Project Background• Cooper Crouse-Hinds develops luminaires that are used in hazardous

environments where ignition or explosion can have catastrophic consequences.• To pass safety requirements for certification the luminaires must meet a series of

Underwriters Laboratories Inc. Standards.• A Vibration Test Stand is currently being used by Cooper Crouse-Hinds to test

pendant mount luminaires according to section 33 of the UL844 Standard. • The Current Vibration Test Stand is outdated, has multiple design flaws, and design

documentation and drawings are non-existent.• Cooper Crouse-Hinds would like a new Modernized Vibration Test Stand to be

developed that addresses some of the design flaws of the current system while maintaining UL844 Test Standards. This new Design must also have a LabView interface and control capability integrated into the system.

January 11, 2013


Design Goals over Winter/Spring MSD

Note: It has been decided that this apparatus will be developed in multiple Senior Design Sequences.

• Provide customer with two design concepts for vibration mechanism– One of the two designs must be an eccentric shaft mechanism while the customer is open to

considering other design alternatives.– After discussing benefits and costs of the designs in this Systems Level Design Review, the

Customer will decide on the vibration mechanism to be developed further.

• Develop a final design of the vibration mechanism.• Design a steel test frame that will support the vibration mechanism and the

vertical conduit.• Design but do not develop steel frame for entire vibration test machine.• Develop a full set of engineering drawings.• Calculate and select the required drive train system components.• Purchase materials, machine components, and assemble the vibration mechanism

and test frame.• Test the mechanism to ensure that it meets 1/32” deflection requirement

January 11, 2013


Summary of UL844 Vibration Test Standard

LUMINAIRES FOR USE IN HAZARDOUS (CLASSIFIED) LOCATIONS – UL 844Section 33 – Vibration Test Standards

• Luminaire is to be subjected to 35 hours of vibration testing.• Luminaire assembly is to be attached to a 26-1/2” long conduit via NPT threading.

The other end of the NPT threaded pipe is to be secured to the hub of a rigid mounting frame so that the conduit hangs vertically. The conduit should correspond to the smallest size of threaded conduit hub that is designed to attach to the Luminaire being tested.

• The horizontal force to be applied to the system in order to obtain the deflection must me located 4” above the location of the conduit where the Luminaire attaches.

• The deflection must be 1/32” with 1/16” total deflection per cycle.• The system must run at 2000 cycles/min.

January 11, 2013

Force Applied to Deflect Luminaire

Equations of relative motion were applied to derive the acceleration of the desired deflection assuming a constant angular velocity of the primary shaft. The moment of inertia was than approximated for the conduit with 100lbf cylinder at its end. Assuming the system acted as a pendulum and using the moment of inertia and acceleration we acquired a force. This was then superimposed with the force needed to bend the conduit (cantilever pipe) to the proper deflection.

The calculated force was approximately 400lbf.January 11, 2013 UL Vibration Test Apparatus 6


UL844 Vibration Test Standard

January 11, 2013


Design Flaws Associated with Current Design

January 11, 2013

• Difficult for one technician to set up test• Lubricant not contained• Machine components exposed to contaminants• Belts used (slipping)• Uses single speed motor with a speed reducer• Frequency adjustment dial held in place with rope• No displacement adjustment • Attachment collar may experience minor buckling• Does not accounted for part wear and tolerance stack

up

Customer Design Needs

Need # ImportanceHigh 3 – 2 – 1 Low

Design Criteria Measure of Effectiveness

CN1 3 Obtain vibration frequency of 2000 cycles/min Stroboscope

CN2 3 Create displacement of 1/32” at 22.5” bellow pipe flange Dial Gauge

CN3 2 Adjustment of attachment collar position for perpendicularity ___

CN4 2 240 V electrical input ___

CN5 2 System envelope size is maintained or decreased from original system ___

CN6 1 Mounts to current anchor points in floor ___

CN7 3 Capability to adjust for different pipe sizes ___

CN8 1 Use current flange mounting for pipes ___

CN9 2 Design in an easily removable collar ___

CN10 3 Will support multiple types of Luminaires ___

CN11 2 Easy to mount the Luminaires 1 Technician can run entire test

CN12 1 Ease of lubrication ___

CN13 2 Containment of Lubricant Look for leaking of Lubricant

CN14 3 System to not run near resonate frequency Does not shake itself apart

CN15 1 Minimize noise of system Under 85 decibels(OCIA standard for requiring

ear protection)

Rotational Input at 2000 rpm

Rotational to Linear Motion Mechanism

Options:

• Eccentric Shaft• Crankshaft Variation for

Adjustment Capabilities• Scotch Yoke

• Variation for Adjustment Capabilities?

• Cam Follower

Output Linear Motion to Slider

Mechanism

• Allows for design of a single motor input and slider output mechanism for either the eccentric shaft or scotch yoke design

• Slight adjustments to frame required for each case due to the orientation of the motor (either horizontal or vertical)

January 11, 2013 UL Vibration Test Apparatus 10


Continued (next slide)

Functional Decomposition (Page 1 of 2)


Functional Decomposition (Page 2 of 2)

Slider Mechanism

Linear bearing with rails

Roller bearings w/ wheels

Full fluid boundary w/ lubricant

Magnetic

Pillow block bearings Notes:

• Ranked from top to bottom, best to worst

• Need to ask exactly what mechanism the current design employs

• Issue is lubrication and lubrication containment if bearings are not used


Rotational to Linear

Mechanism

Scotch Yoke

Crankshaft

Cam Follower

Screw Actuator

Eccentric Shaft Notes:

• Ranked from top to bottom, best to worst

• Also a linear motor option that does not fall under this category but still converts electrical energy to mechanical


PUGH Matrix: Rotational to Linear Motion Mechanism


# Evaluation Criteria Crankshaft Eccentric Shaft Scotch Yoke Cam & Follower1 Robustness s + + -2 Cost + - + s3 Design Simplicity s + s s4 Adjustability s - + s5 Component Wear s s - -6 Ease of Lubrication - + - -7 Part Replacement s - + +8 Accuracy/Tolerance Stack-up + + + -9 Ease of Maintenance s s + s10 Ease of Manufacture + - + s11 In-house Manufacture + - + s12 Ease of Assembly s s s s13 Noise/Vibration + + - s14 Safety s + s s

4 1 5 -3

Rotational to Linear Conversion

Sum

Ecce

ntric

Sha

ftEccentric Shaft

(Custom Purchase)

Shaft Bearing(s)(Purchase)

Connecting Rod(Custom)

Connecting Rod Bearing(Purchase)

Shims(Purchase)

**Note: Green boxes denote optional design components

Notes:

• Current design in use at Cooper

• Simple design• No adjustment

capability• Eccentric shafts

expensive to purchase• Relatively few moving

parts• Lubrication of

connecting rod must be further studied

Option 1


January 11, 2013

Scot

ch Y

oke

Rotary Disc(Custom)

Shaft(Purchase)

Yoke Plate(Custom)

Pin(Purchase)

Connection to Slider Mechanism

(Custom)

**Note: Green boxes denote optional design components

Notes:

• Alternate design• Fairly simple• Adjustment capability• Lubrication of system

must be further studied

Gear (Purchase)

Key (Purchase)

Option 2

May be directly built into design

Scotch Yoke CAD Concept


PUGH Matrix: Slider Mechanism


# Evaluation Criteria Pillow Block Bearings Viscous Fluid Layer Roller Bearings w/wheels Linear Bearings on rails1 Robustness + + S +2 Cost S + S S3 Design Simplicity S S - S4 Component Wear + - S +5 Ease of Lubrication + + S +6 Containment of Lubricant S - S +7 Part Replacement + - + +8 Ease of Maintenance + S + +9 Ease of Manufacture + + S +

10 In-house Manufacture S S S S11 Ease of Assembly S S S S12 Noise/Vibration S - S S

6 0 1 7

Slider Mechanism

Sum

PUGH Matrix: Displacement Adjustment Mechanism


# Evaluation Criteria Screw Linear Actuator Pivot Cam slider w/ tightening bolt1 Robustness - + -2 Cost - + +3 Design Simplicity - + +4 Part Replacement - + S5 Accuracy of Adjustment + - -6 Ease of Manufacture - S +7 In-house Manufacture - + +8 Ease of Assembly - + +9 User Friendly + S S

-5 5 3

Displacement Adjustment Mechanism

Sum

Cost Analysis


Component Count Approximate Cost Per ItemScotch Yoke Yoke 1 $20

Drive Shaft 1 $120 Rotating Plate 1 $100

Pin 1 $20

Bushing 1 $40

Stroke Adjustment Mechanism 1 $40

Eccentric Shaft Eccentric Shaft 1 $500 Pivot Arm 1 $100 Shaft Bearings 2 $40

Pivot Arm Bearing 1 $20 Guide Rail System Bearing 1 $20 Frame Base plate 12" wide x 3/4" thickness x 48" long 1 $230 Channel Plate 12" wide x .380 thickness x 72" long 1 $250 Steel Angle 6 $200 Fasteners and Associated $200 Guide Rail System Linear Pillow Block Bearings 4 $320 Hardened Ground Shaft 2 $120 Shaft Base Mounts 4 $100 Assorted 2" NPT Pipe 26.5" length 1 $30 Dial Indicator 1 $30 Pipe Flange 1 $40 Approximate Cost w/ Scotch Yoke $2,100 Approximate Cost w/ Eccentric Shaft $2,600


Risk Assessment


Continued (next slide)

Project Schedule (Page 1 of 2)


Project Schedule (Page 2 of 2)

Suggested Design Implementation

• Scotch Yoke Design• Linear Bearings on Rails• Pivot Cam for Eccentric Adjustment

Mechanism• AC Motor with Adjustment• Redesigned Flange Platform


Open Discussion

• Any questions?• Design concerns not discussed?• Feed back on work done to this point?• Feed back on method for calculating

deflection force?• Follow-up meeting needed?

• Customer decision on Vibration Mechanism


systems level design review ul vibration test apparatus january 11, 2013 kgcoe room # 2255...

Documents

vibration mechanism

current vibration test

entire vibration test

new design

ul844 test standards

steel test frame

design goals

design documentation