04 New drive design for Pfeiffer MPS mills - Dr ... - Gebr. Pfeiffer SE

GEBR. PFEIFFER AG
New drive design
for Pfeiffer MPS mills
Dr. Dirk Hoffmann
Progress is our tradition

Subjects
1. Motivation
2. Potential of the solution
3. Design principle
4. Customer benefit
5. Risk evaluation
6. Development status / future prospects
Subjects
TK-N/Hof 02/05
GEBR. PFEIFFER AG

1. Motivation
conventional bevel-planetary gears available up to approx. 6,000 kW
increase in mill size: power ratings > 5,000 kW and i > 50 require:
further development of conventional gear units
Flender: KMP => KMPS
Maag: development of a 3-stage
gear unit > 5,000 kW
Renk: KPAV => KPBV
new development of GP / Flender:
DMGV girth gear unit
Motivation
TK-N/Hof 02/05
GEBR. PFEIFFER AG

Flender KMP
Gearbox
Flender KMP
TP/ Ne- 08 / 04
GEBR. PFEIFFER AG

Flender KMPS
Gearbox
Flender KMPS
TP/ Ne- 08 / 04
GEBR. PFEIFFER AG

Renk KBPV
Gearbox
Renk KBPV
TP/ Ne- 08 / 04
GEBR. PFEIFFER AG

2. Potential of the solution – history of DMGH
DMGH girth gear units successfully used on tube mills up to 11,000 kW
since 1989
approximately 290 DMGH units sold, 120 of these in the past 5 years
DMGH 30 DMGH 25,4 DMGH 22 DMGH 18
Potential of the solution – history of DMGH
TK-N/Hof 02/05
GEBR. PFEIFFER AG

2. Potential of the solution – DMGV
Basic functions of a mill gear unit:
conversion of torque / speed
suspension of axial mill load
change of direction of rotation from horizontal to vertical
DMGV of modular design, 3 modules:
DMGV 22 : 3,000 kW
DMGV 25,4: 4,500 kW
DMGV 30 : 5,500 kW
covering the range from 3,000 to 11,000 kW either as single or twin drive.
Actually, this makes sense from > 5,000 kW.
Potential of the solution – DMGV
TK-N/Hof 02/05
GEBR. PFEIFFER AG

2. Potential of the solution – allocation of model ranges
Allocation of MPS model ranges to DMGV model ranges:
today: for 6 MPS mills with grinding bowl diameters from 5,600 to
7,300 mm, 30 gear units are required, covering a range from 3,000
to 11,000 kW and an axial load range from 6,600 to 28,500 kN
(MPS-BC: 2 speeds each / MPS-B: 3 power modules each)
DMGV: 3 modules: DMGV 22 / DMGV 25,4 / DMGV 30:
3 gear units are required
gear rim and axial bearing are selected individually
Potential of the solution –
allocation of model ranges
TK-N/Hof 02/05
GEBR. PFEIFFER AG

3. Design principle – DMGV gear units
train of wheels supported on roller bearings and case hardened; AGMA
2.5 referred to P inst
GEBR. PFEIFFER AG
4 gear stages:
1. input stage comparable with conventional
bevel-planetary gears, however, with a
smaller bevel gear
2. spur gear stage
3. load distribution by means of a floating
intermediate shaft; mass balance by
means of helical gearing
4. output onto gear rim with two self-aligning
pinions
gear units with enclosed housings => not
comparable with the open, grease lubricated
girth gear units
Design principle – DMGV gear units
TK-N/Hof 02/05

3. Design principle – details of DMGH
gear rim
floating
intermediate
shaft
self-aligning pinions
sketch showing principle of
wheel train in the main gear unit
Design principle – details of DMGH
TP/ Ne- 08 / 04
GEBR. PFEIFFER AG

3. Design principle – gear rim and axial bearing
gear rim:
integral part of the gear unit => oil lubricated
cast steel / hob cut teeth
AGMA 2.5 referred to P inst
axial bearing:
comparable with conventional
bevel-planetary gears
gear housing not exposed to
grinding forces
Design principle – gear rim and axial bearing
TK-N/Hof 02/05
GEBR. PFEIFFER AG

4. Customer benefit: I. capital investment
single-mill concept: > 5,000 kW also possible => reduced investment
for mill
security of investment: increase of mill size / mill capacity with proven
components 290 DMGH gear units sold
standardization: in the range from 3,000 to 11,000 kW 3 modules rather
than 30 gear units => reduced investment for mill drive > 5,000 kW
Customer benefit
I. capital investment
TK-N/Hof 02/05
GEBR. PFEIFFER AG

4. Customer benefit: II. production
temporary operation with one drive assembly in the case of a twin drive
(60% grinding capacity) => no shutdown of production during maintenance
work on the gear
maximum reliability thanks to reduced time requirement for inspection
and rapid availability of spare parts
maximum reliability: gear rim => as compared with conventional gear
units, robust design including the option of emergency repair of individual
teeth by welding
Customer benefit
II. production
TK-N/Hof 02/05
GEBR. PFEIFFER AG

4. Customer benefit: III. maintenance
maximum reliability thanks to simplified spares inventory
standardization / 3 modules and gear sizes, respectively
gear unit not exposed to grinding forces => contact pattern remaining
unchanged => longer lifetime
ease of access: inspection and maintenance work on gear is
facilitated
visual inspection can be done on complete wheel train
during removal of the gear unit, the grinding bowl can remain on the
axial bearing and the electric motor can be left in operating position
Customer benefit
III. maintenance
TK-N/Hof 02/05
GEBR. PFEIFFER AG

5. Risk evaluation
lack of field experience with the DMGV gear on the roller mill
operating behavior of the roller mill is different from that of the tube mill
mechanical dynamics of the vertical distribution shaft => mass
balance provided
(electrical) dynamics with twin drive
tightness of housing is increased compared to the DMGH gear on a
tube mill, i.e. it is similar to that of conventional bevel-planetary gears
Risk evaluation
TK-N/ Hof 02/05
GEBR. PFEIFFER AG

6. Development status / future prospects
DMGV 22 design completed
DMGV 25,4 and DMGV 30: conceiving stage completed
Development status / future prospects
TK-N/Hof 02/05
GEBR. PFEIFFER AG