CMS ZDC Remote Handling Tool(ZDC Crane)

Force Calculations and Mechanical Analysis

Calculations of Driveline loads and forcesFEA reports of Structural Components

P. DebbinsUniversity of IowaMay 12, 2014

Calculations of Normal operating forces for worst-casePayload (Stainless Bars) present in the movement drivelines.

Actuator jack loading and input drive forces:M1 (Vertical Axis) DrivelineM3 (Rotational Axis) Driveline

Bearing loading in jointed structures.

Listing of Component specificationsCalculation of Stress levels and safety factors

The reader of this document should be familiar with the document:CMS ZDC Crane Structural Assembly Reference

CMS ZDC Remote Handling Tool (ZDC Crane)

Force Analysis of Actuators-Drivelines-Motors

Calculation of Working LoadsWorst case load is Stainless Bars

Rotary Axis: 2 x Merkur M3 Actuators.Suspended load on rotary system. This Is NOT the direct load applied to actuators

Vertical Axis: 2 x Merkur M1 Actuators:Lift vertically (against Gravity) at Arrows

60 kg

316 kg

58 k

g

316 kg

58 k

g

434 kg = 4256N

534 kg = 5236N

Center of Gravity of SS Bars offset from Crane centerline: imbalances Actuator loading +/- 3%

Each actuator : (4256N / 2) = 2128N

Add 5% for imbalance: M1 actuator load = 2235N forEach M1 actuator.

60kg

100kg total(3 pieces)

The suspended load is coupled to M3Actuators via a rotary-linear crank Mechanism. Calculation of the actuatorLoading follows in a later section of thisDocument.

Calculations for M1 (Vertical Axis) Driveline

11

2 33

45 1. Pfaff-Silberblau Merkur M1 Type2 jack

2. R+W Line shaft: EZ2/10/948/B/10PFN/10PFN3. R+W Coupling: EKL/5 + 10mm shaft (one side)4. R+W Torque limiter: ES2/5 (A) (W) 3 – 6Nm5. Baldor Servo Motor: BSM63N-375AA

Exploded view and component listing

1: Pfaff-Silberblau Merkur M1 Type2 (traveling Nut)

Component Specifications and Calculations of Drive parameters

Maximum Lift = 5kN (ZDC tool requires max. 2235N) Safety Factor = 2.24. Lift is tension only, no buckling forcesLow gear ratio (16:1)Maximum input shaft speed = 1500rpm (ZDC tool operates at 1000)Maximum input shaft torque = 3,4Nm (Torque limiter set at 3,2Nm)Input shaft torque to lift 2,5kN @ 1000rpm = 0,4Nm (for each M1 Actuator)Stainless steel screw, Bronze EFM type traveling nutLow ratio lifts 0,25mm / input revolution> @1000rpm input lift = 250mm / min. Total lifting time for tool to raiseor lower payload vertically = 2:28 min.

2: R+W EZ2/10/948/B/10PFN/10PFN Line Shaft

Rated torque = 12,5Nm (Torque limiter set to 3,2Nm) Safety factor = 3.9Critical Speed = 2707 rpm (line shaft operated at 1000)Line shaft coupling is with keyway to positively mechanically index twin M1 actuators

3: R+W EKL / 5 coupling

Rated torque = 12Nm

4: R+W Torque Limiter ES2/5/A/W/10/11/3,2/3-6

Disengagement torque set 3,2Nm (M1 actuator input max = 3,4Nm)Limiter reengages automatically when overload is removed. Operating input torque of ZDC M1 (vertical) drive line is ~ 1,2Nm (both actuators together). Limiter only engages in case of mechanical jamb, protecting all drive components against excessiveforce input. (M1 Driveline motor peak torque (3 sec) = 8,36Nm)

5: Baldor Servo Motor BSM63N-375AA

Continuous stall torque = 2,09Nm @ 2,82A currentPeak torque = 8,36Nm @ 10,1A currentMax speed 7000 rpm (motor operated at 1000rpm)

Operational testing of M1 (vertical axis) driveline

Operating the crane has shown the M1 (vertical) driveline to require a totalInput of 1,2Nm to drive both M1 actuators lifting a load (together) of 487kg.This is using the Test Payload which is heavier ~12% than the stainless steel barsWhich are the worst case intended operation.

All driveline components and motor are operating well within their ratings and safetyFactors are high.

System is mechanically torque limited to 3,2 Nm (3,4 Nm torque input to M1 actuators isThe weakest part of the driveline).

Calculation of M3 jack screw load. Screw load depends on position of System in rotation. 3 positions of crane are illustrated: maximum extensionTo Sarco (#1), Maximum vertical (centered over pivot point) (#2), and fullRetraction centered over TAN (#3)

#1 #2 #3

Full Rotational Extension (Centered over Sarco). Maximum Tension load to actuator.

Vertically centered overPivot point – zero load toActuator.

Full Rotational Retraction(Centered over TAN).Maximum Compression Load on actuator.

M3 Actuator screw loading calculation

5236

N 5236

N

5236

N

F=0

Dynamic Simulation – Computation of spindle load – full motion range

2750

N

Total suspended load = 5236N(5236N / 2) = 2618N

Add 5% for imbalance: Each M3 actuator mustApply force to rotate a suspended load of 2750N

Force Graph

#1 #2#3

Pos #1 Absolute max load: 10266N TensionPos #2 No load on M3 spindlePos #3 Max Compression (Buckling) load: 2352N

Calculations for M3 (Rotational Axis) Driveline

1 1

23

4 5 67

1: Pfaff-Silberblau Merkur M3 Type 1 jack2: R+W Line shaft EZ2/20/1152/B/16PFN/16PFN3: R+W Coupling: EKL/104: R+W Torque Limiter: ES2/10/A/W/16/20/8,3/4-125: Stainless Steel shaft adapter 6: Fenner Trantorque GT keyless bushing7: Baldor Servo Motor: BSM90C-3150AA

Maximum Allowable Compression loadOf Actuator Screw is a functionOf extension length

The Case for CMS ZDC Tool isEuler II

Factory charts show for M3 With 30x6Tr screw Euler case II2500N permissible buckling force isAllowed up to 1400mm extension.

The ZDC tool M3 actuator experiences2352N buckling force at Extension length = 35mm

Buckling force diminishes to 0 at Extension 120mm, where for all Further extension it becomes a tensionLoad.

Max tension load experienced = 10,27kNM3 allowable tension = 25kN

Safety Factor = 2.4 (under tension)

1: Pfaff-SilberBlau Merkur M3 Type 1

1: Pfaff-SilberBlau Merkur M3 Type 1

Maximum Lift = 25kN (ZDC tool requires 10266N tension max) Safety Factor = 2.4 under tensionBuckling force loads are trivial with respect to the M3 specificationsLow Gear ratio (24:1)Maximum input shaft speed = 1500rpm (M3 driveline operates at 1000rpmMaximum input shaft torque = 18Nm (R+W torque limiter set at 8,3 Nm)Input shaft torque to lift 10kN @ 1000rpm = 2,1Nm (for each M3 Actuator)Low ratio lifts 0,25mm / input revolution : @1000rpm input: Lift = 250mm / min. Total time forTool to fully move between TAN and SARCO positions = 2:43 min.

2: R+W EZ2/20 Line Shaft

Rated Torque = 17Nm (Torque limiter set to 8,3Nm) Safety Factor = 2Critical Speed = 2406 rpm (System operated at 1000 rpm)Line shaft coupling is with Keyway to positively mechanically index twin M3 actuators

3: R+W EKL / 10 Coupling

Rated Torque = 16Nm

4: R+W Torque Limiter ES2/10/A/W/16/20/8,3/4-12

Disengagement torque = 8,3Nm. Operating input torque to M3 driveline is ~ 5Nm (both actuators operating at worst case loading position) Torque limiter reengages automatically when overload is removed. Limiter only operates in case of Mechanical jamming, to protect all driveline components from damaging overloads in event of mechanical Jam. M3 driveline motor peak torque = 23,4Nm (3 sec)

5: Shaft Adaptor. Custom part. Consult the document:

CMS_ZDC_Crane_Mech_Structures(1).pdf

6: Fenner Trantorque GT 6202820 24mmx45mm

Maximum holding torque = 380 Nm

7: Baldor Servo Motor BSM90C-3150AA

Continuous stall torque = 7,8 Nm @ 6,0 A currentPeak torque = 23.4 Nm @ 15,4 A currentMax speed 5000 rpm (motor operated at 1000 rpm)

FEA CalculationsComponents Naming

HAD Bars

EM

Bar

s

Carrier Beam

Overhead Beam

Sid

ewal

l

Sid

ewal

l

Lifting Bridges

Lifting Lugs

HAD Type

4x bridges carry 335kg84kg / ea. bridge

EM Type

2x bridges carry 68kg34kg / ea. bridge

FEA of Lifting Bridge ComponentsForce Loading

84kg (Nom Load) 840N252kg (3x overload) 2520N

34kg (Nom. Load) 340N102kg (3X overload) 1020N

Interconnect Pin

FEA Simulation modeled in static equilibrium withForces applied at bolts (shown in arrows) and at Surface of pin contact to shoe or foot.

1x (Nominal) and 3x overload considered

FEA result: HAD type “foot” and “shoe”

Hadronic Foot : Hadronic Foot FEA

Hadronic Shoe : Hadronic_Shoe_FEA

EM Foot : EM_Foot_FEA

EM Shoe : EM_Shoe_FEA

All lifting bridge components are minimally stressed (safety factor > 15)

Results are posted at links below:

Carrier Beam FEA

M10 x 90 hex bolt(8,8)

Fixed constraint (M1 traveling nut)

F(em)

F(Had)

F(em) = 180N each bolt (4 places) 1x loading 540N each bolt (4 places) 3x overload.

F(Had) = 430N each bolt (8 places) 1x loading 1290N each bolt (8 places) 3x overload

Carrier Beam FEA reports posted: Carrier_Beam_FEA

340N (1x)1020N (3x)2 places

840N (1x)2520N (3x)4 places

Overhead BeamF = 2235N (2 places) Nom. loading 6705N (2 places) 3x overload

With imbalanced load eachM1 actuator is modeled to carry2235N

FEA Results posted: Overhead_Beam_FEA

FixedConstraint

Fixed Constraint

Overhead Beam FEA

Sidewall FEA and force modeling is here

54N

0.71 deg. Offset from vertical creates a sideways (along Z axis) thrustof suspended payload. 0.71 deg. angle of 4256 suspended load resultsIn 54N thrust in Z.

54N

FixedConstraint

2445N – Combined 2235N of M1 actuator and Overhead masses

Sidewall FEA posted : Sidewall FEA

Rotary System components naming

M3 Actuator

Swivel MountRotary Arm

Pivot Mount

Calculation of Forces in Rotary SystemRotary arms, bearings, Pivot and Swivel Mounts

Bearing Loadings

3

1

2

4

1: 2x SKF 32005 X/Q Taper Roller Bearings. Nominal load = 2750N (per 2 bearings)

2: 2x SKF 32005 X/Q Taper Roller Bearings. Nominal load varies with rotary position. Worst-case load = 10855N (per 2 bearings)

3: 1x SKF 22205 E Spherical Roller Bearing. Nominal load varies with rotary positon. Worst-case load = 10266N. This bearing isolates the M3 spindle from side loading by any misalignment and/or deflection of the rotary arm.

4: 2x SKF NA 4905 Needle Roller Bearing. Nominal load varies with rotary position. Worst-case load = 10266 (per two bearings)

All Actuators and Bearings are lubricatedWith Dupont Krytox 227Radiation Resisting Grease

See Mechanical ReferenceFor Radiation Testing DataAnd Specifications

5236N total suspended load

2750N 2750N

33N 33N

Forces present on each Rotary Arm

2750N force represents +5% from Nominal to provide worst-case

FEA of Rotary Arms

0.71deg offset in Z direction results in 33N thrust per arm

FEA input forces: 2750N (1x) and 8250 (3x overload)

50N (1x) and 150N (3x overload) for Z axis thrust.

FEA Results Postings:

Rotary Arms: 1x loading: Rotary Arm (1x loading)3x loading: Rotary Arm (3x loading)

Pivot Mount: 3x loading: Pivot Mount (3x loading)

Swivel Mount: 3x loading: Swivel Mount (3x loading)