Shaft Mount GearboxesGrain Industry

GEAPS Angola 2017

� Shaft mount gearbox overview

› Safety

› Applications

› Sizing and selection

› Installation

� Advanced shaft mount topics

› Motor torque basics for conveyors

› Dual drive

› Fluid couplings and VFD’s

� Beltless solutions

› Motorized Torque Arm overview

Agenda

| © Baldor Electric Company2

Foot mounted reducerLate 1940’s

Shaft mounted reducerDodge invention - 1949

Shaft Mount Gearbox Overview

| © Baldor Electric Company3

Grain industry drivers: safety

Head Section

� Reducer (belted or beltless)

� Option: Creep Drive

� Roller bearings (9 in max)

� V-Belt

� Motor mount belt guard:

offset

� Conveyor pulley: Slide Lag

Discharge

Boot Section

� Ball / roller bearings

� Drum pulley

Applications: Bucket Elevator

5

Grain inlet

Right hand drive

Buckets

Applications: Bucket Elevator

| © Baldor Electric Company6

Applications: Mechanical Creep

| © Baldor Electric Company7

Bucket elevator: >75HP� Used to slow down belt during inspection

� 10% of total HP

� Dual drives: TA12 / 400HP

Applications: Chain & Belt Conveyors

| © Baldor Electric Company8

Applications: Screw Conveyor

| © Baldor Electric Company9

Gearbox selection info

Application = conveyor belt drive

HP = 60,

Output speed = 80 rpm

Hours = 12 per day

Loading = uniform

Shaft diameter = 4-7/16”

Backstop & TA Rod kit

Motor mount & Belt guard

Selection Procedure

Step 1: Service factor

Conveyor, Uniformly loaded,

+10 hrs per day

Select = Class 2

Sizing and Selection

Step 2: Determine reducer sizeClass II, starts page G1-22, 60 hp is on page G1-24Choose between 7315H25 and 7315H15Divide 1750 by the 80 rpm output speed � 21.9:125:1 would require a speed up drive so use the 15:1

Step 3: check reducer bore against shaftShaft 4-7/16” does not seem to fit the reducer nominal bore of 315TA7315 max bore is actually 4-7/16

Step 4: Select part numbers and accessories page G1-89Reducer TA7315H15 = 907002Bushing TA7315TB x 4-7/16” = 907019Rod TA7315/8407RA = 907109BackstopTA7315/9415BS = 907102Motor Mount TA7315/8407MM = 907090Belt Guard TA7315/8407 BG pos B= 907096

Sizing and Selection

Online Sizing: Passport.Baldor.com

� Starts with the basics

› Motor HP, RPM

• Auto picks frame size

› Conveyor speed

• Helps you convert FPM

to RPM

› SF and thermals

� Result: Complete drive

› Auto-increase case size

when larger bore picked

› Auto-picks belted drive

• Sorts by availability,

price, speed, # belts, etc.

› Save projects for later

Online Sizing: Passport.Baldor.com

Installation – Twin Tapered Bushing

| © Baldor Electric Company16

Standard bushing

Short shaft bushing (TA2 only)

Installation – Backstop

| © Baldor Electric Company17

Installation – Motor Mount

| © Baldor Electric Company18

Stronger, heavy duty

construction fits

larger motors

TA II belt guard fits

flush against the

reducer

Eliminates exposed

moving parts

Eliminates the

possibility of safety

citations

Adjustable gap for

cooling fan

applications

Sheave alignment is key Belt tension is key

Installation - Sheaves

| © Baldor Electric Company19

Month

DD,

Wrong Correct!

Installation – Tie Rod

Motor design elements: service factor, electrical design, and heavy duty features

– Service factor is the amount of

overload a motor will handle within

defined temperature limits without

overheating.

– Motor service factors – more is not

always best

– Motors typically reach peak efficiency

at 50% to 100% of full load

Service factor

50

55

60

65

70

75

80

85

90

95

100

25 50 75 100

Best Practice: To maximize motor life and

efficiency, the application should utilize

80 – 85% of motor nameplate

horsepower

% motor rating

% e

ffic

ien

cy

Motor Torque Basics

Design A & B

Design C

% Motor speed

% t

orq

ue

Motor design elements: service factor, electrical design, and heavy duty features

Electrical design

Best Practice: Review actual motor data

to ensure adequate torque is available

for startup and acceleration

Conveyor Load

- NEMA design classification system

identifies specific motor performance

characteristics

- Conveyors are a constant torque load

when running, but load is 140-160%

at start up

- VFD’s and fluid couplings allow

motors to use full breakdown torque

Motor Torque Basics

� Savings opportunities

› Redundancy – continue

running at half capacity if

one drive fails

› No structure required to

support large heavy

reducer

› Smaller gearboxes

› Parts more readily

available

� Challenges

› One motor can start pulling

more amps and handling

more load

Dual Drives

� Fluid coupling advantages

› Use fluid or steel shot level to

add startup delay

• Reduce electricity usage and shock

through the gearbox, pulleys, and

bearings on startup

› Mechanically balance loads on

dual drive arrangements by

adjusting fluid/shot fill

� VFD advantages

› Precise speed control

› Electricity savings with optimized

startup

› Torque balancing on dual drive

Fluid Couplings and VFDs – Conveyors

Dodge Motorized Torque Arm

� Same high-durability design as Torque Arm 2

› No compromises made on

bearing life or gearing

ratings

› Same accessories as TA2

� Best solution for harsh environments

› Eliminates v-belts

• Lower maintenance cost

• Eliminates pinch points

� 7% energy savings

› 3-piece coupling between

reducer / motor

• Motor can be controlled by

brake / VFD