High Torque Planetary Gears PBLZ for Ball Mill Central Drives

Innovative Power Transmission

Large Horizontal Drives

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Well proven epicyclic gear technology

RENK epicyclic gears are used e.g. in central ball mill drives since 1974 when RENK has supplied the first epicyclic gear for a 2,5 MW ball mill featuring 2 planetary stages each with three planets. The epicyclic gear technology has been the step to take as the powers of the mill systems increased steadily. With new materials, manufacturing technologies, improved lube oils and last but not least condition monitoring technologies, the RENK central drives were improved to their third generation on the market named PBLZ type.

Your Ball Mill, our Central DriveEndurance – Efficiency – Excellence

180 to

tons

165 to149 to

109 to

75 to

Development of the drive technology for ball mill central drives within 50 years: 4 MW drive for a 15.6 rpm mill. At the same time increasing the AGMA service factor from 2 to 2.5. The weight is the system weight including couplings.

Spur gearing with 2power-transmissionpaths

Spur gearing with 3power transmission paths

2 stages

2 planetary stages, 1 parallel stage

2 planetary stages, 1 parallel stage, hydrodynamic bearings

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The Drive System Design Complete package of equipment

3 Main Gear / Coupling: 14 - 18 rpm4 Cement Mill5 Oil System, optional with SCS Controller

1 Auxilliary Gear for positioning an balancing of mill body with: Motor, Hydrodynamic Clutch-Retarder, Back stop Brake System, Reducer, semi automatic Claw Clutch Ratio: > 80002 Main Motor: 3000 - 10000 kW; 750 - 1500 rpm

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Large Horizontal Drives

Nominal speed

Aux drive speed

time

Stop signal or black out 30 to 60 sec.

Max.kinetic Energy

Startoperation

Max.potential Energy

forw

ard

spee

d

back

war

d sp

eed

Mill Stop The mill swings to stop after a motor stop. This requires backward rotation.

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RENK Auxilliary Drive System

1 Claw Clutch: engaged until overruning takes place; manual disan- gagement only after balancing2 Auxilliary Gear: reducer3 Drum Brake: opening electically only with interlock to oil pressure4 Hydraulic Clutch: clutch works as a dynamic brake for balancing the mill in controlled manner5 Auxilliary Motor: equiped with back stop – can not turn reversly

Auxilliary Drive System Features

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Large Horizontal Drives

Safety and DependabilityAre on Top of the List

RENK will provide all components of the drive system! The condition of all elements is continuously monitored by sensors and switches. A logic diagram provided to configure a Programmable Logic Con-troller (PLC) or a readily programmed Sub Control System (reporting to the main PLC) is available. The RENK programmed and tested SCS shortens the commissioning time and reduces the risk of site work mistakes.

In any case the operation is save and interlocked against faulty operation.

The Oil System features a hot standby pump, a double switch fil-ter system with remote clogging indicator and a temperature control valve to provide constant operation conditions also at changing cool-ing media. The oil quantity born in the tank is rated generously to al-low an extended running time without oil change. The oil is continu-ously fine filtered to minimise the impact on the gear elements by abrasives which cannot be prevented to penetrate the oil circuit in the cement plant environment.

In addition to all those elements an emergency oil tank is provided to make sure the shaft system can coast down safely in case of frequent black outs or a delay in stopping the main motor in case of a major failure of the system. Two minutes of operation are possible without power source.

Nominal speed / torque

Aux drive speed

time

forw

ard

spee

d

back

war

d sp

eed

maintenance

Open brake

maintenance

Close brake

Gear unit

Terminal box

Oil supplyunit

Starterboxlube oil pumps andimmersion heater

with local operation

Power SupplyCustomer

SCSSub Control System (SCS)

RENK PLC with local screen

Powercable

Powercable

Profibuscable

Controlcable

Controlcable

Central Control System (CCS)

The backstop on the auxiliary drive motor turns the hydraulic clutch into a retarder for controlled ballancing – brake is opened electrically and is interlocked with oil pressure for gear.

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1 Local Instruments: optional SCC2 Water Cooler: optional air3 Stand by Pump: no stop for pump failure4 Main Line Filter: 40 um cleaneable, stainless steel5 Pypass Filter: 10 μm non cleaneable, fleace6 Tank: approx 5 times pump cap7 Heating: 21 kW

The Oil System Features

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Large Horizontal Drives

• 3-stage design for compactness and safety. • Moderate bearing loads to provide safety margin. • Hydrodynamic sleeve bearings are selected for

ultimate lifetimes. The lifetime of sleeve bearings is mainly subject to propper lubrication! In case white metal bearings are wiped out repair is possible.

PBLZ Ball mill drives feature all over hydrodynamic sleeve bearings. The bearings of the two planetary stages feature brass surfaces to be most resistant against any adverse operation condition. The brass bearing metal provides a higher strength than usual white metal spindles. Gears are case hardened (except annulus) and precision machined. The casing is cast from cold climate enabled globular cast iron. Fine filtration minimizes wear of gears and bearings.

Before we supply our gears we carefully assemble them by skilled hands and test the complete system on our test bed.

Our Gear Lifetime Makes Your Money

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Large Horizontal Drives PB

LZ r

atin

g ta

ble

Max

imum

Tor

que

Typi

cal m

ill s

peed

Max

imum

pow

er

Leng

th L

Ø of

Cas

ing

Cent

er D

ista

nce

(CD)

Wei

ght o

f gea

r un

it

Gear size kNm rpm kW mm mm mm tons

160 1,750 16.5 3,000 2,750 2,120 560 32

180 2,400 16.0 4,000 3,050 2,320 592 43

200 3,200 14.8 5,000 3,300 2,620 710 56

225 4,500 14.8 7,000 3,560 2,970 830 76

250 6,500 14.5 10,000 4,030 3,330 1,000 102

Condition Monitoring and Service Completes the Package

Long life time is the result of good equipment and proper mainte-nance. The RENK Service group is not only present for installation and troubleshooting but can assist on a regular basis in the frame of a maintenance contract.

Such assistance includes the judgement of the outputs from the condition monitoring system which is supplied with the equipment. With such results preventive maintenance can be planned well aimed.

n: speed T: temperature p: pressure a: acceleration (vibration) s: position

a a

T T

T

T

T

a

s

T T

Main Filter

Maintenance Filter

T

p

p

p

Lube Oil Inlet Ø

L

CD

n: speed T: temperature p: pressure a: acceleration (vibration) s: position

a a

T T

T

T

T

a

s

T T

Main Filter

Maintenance Filter

T

p

p

p

Lube Oil Inlet Ø

L

CD

Designs ready for use

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The RENK PBLZ Central Drive at a Glance

Questions to ask before you decide The following has been found to be advantages of RENK central drives:

Feature – RENK has it! Why do you need this?

Planetary design (low speed stages) High torque Parallel shaft gears and to deflect under torque affecting the load pattern and are ultimately heavy

3-stage design with compact dimensions Compact parts means to save parts cost. Ratio can go up to 100 with no problem – i.e. 4-pole standard motors can be used

Best quality materials and QA made in GermanyCleanliness for increased lifetime of the components especially in abrasive atmospheres; hot LP pump for uncompromising availability; oil viscosity optimization for oil pump power saving.

Hot stand by pump, bypass cleaning, temperature control valve

ISO4406 20/17/14 cleanliness increases lifetime; hot LP pump for uncompromised availability; oil viscosity optimization

High margin and no restricted lifetime elements All sleeve bearing design; AGMA Sf > 2.5; ISO6336 Ka > 1.6 & Sf > 1.6 & Sint > 2.0;

Temperature, Vibration and Mill Axial Position Condition monitoring for preventive maintenance and proactive maintenance

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RENK Aktiengesellschaft

Werk AugsburgGögginger Straße 73 86159 AugsburgGermanyTelefon +49.821.5700-0Telefax +49.821.5700-460E-Mail info.augsburg@renk.biz

www.renk.eu

High Torque Planetary Gears PBLZ for Ball Mill Central Drives