YILMAZ REDÜKTÖR VR Serisi

YILMAZ REDÜKTÖR
Gearbox Selection
Parameters
R & D Department
Murat Cem Ünal
22.06.2011
This is a graph of the magnitude of a cyclic stress against the logarithmic scale of cycles to failure.
The curve depends on material fatigue properties
Miner
Endurance limit
Corten|Dolan
Haibach
Number of load cycle
Torque values has to be obtained from test results or simulations
Can be used to determine required service factor
T1
T2
Tn - 2
Teq
…
Factor for pitting by
case carburized and
through hardened
materials
Tn - 1
Tn
Time
Dt1
Dt2
Dtn
t
ISO 6336 takes fatigue of tooth root and tooth flank into account
Pitting calculations are based on Hertzian contact stress
Both calculations respect the effect of tangential force
Better fatigue strength of tooth base
Hardening of tooth root area
Optimum addendum
Fatigue of tooth base
Optimized tool
Pitting
Better foot rounding
Less pitting
Better oil
Bearing
Optimum profile shift
Better roughness of tooth
shoulder
Speed [rpm]
Standard Profile
Modified Profile
Factor of safety for critical section of shaft
Determination of
critical section of shaft
Material properties
Part specifications
Calculation of tension
at the critical section
Standard to calculate bearing life time
Equivalent radial and overhung load for bearing calculations
Equivalent Load
Factors
Axial Load
Radial Load
Life time calculation
Load rating
Bearing life time at which
ninety percent of the
bearings will still be operating
Equivalent
load
Life-equation
exponent
Working
Conditions
Standards
Safety
Nominal
torque of
gearbox
Values to
Customers
• Under uniform load & 8 hours per day
• Life time of product
•Ambient temperature
•Dust at working place
•Humidity …
•ISO 281
•ISO 6336:2006 (new), DIN 3990
•DIN 743
•Bearing Life
•Gear Safety
•Shaft Safety
•Stress analysis of housing
•Minimum torque of all calculations
•Transmission ratio
•Output torque …
Determining nature of load
External moments of inertia reduced on motor shaft
Nature of Load
Transmission ratio
Moment of inertia of the motor
Choosing factor for nature of load
U
Uniform load
Fi < 0.25
M Moderate load
0.25 < Fi < 3
H
3 < Fi < 10
Heavy shock load
For Fi > 10 contact with us
With experimental measurements or simulations
Teq
Time
Basic measurement influences like:
Sampling time
White noise
Sensitivity of sensor
Determining the service factor from calculations or
measurement results are complicated and not
practical .
Last but not least method to obtain service factor is:
Determining the service factor
based on experiences depending
on various sectors!
Service factor is a safety coefficient, which takes different running conditions and peak loads
into account
fs = 1 means that you have:
Uniform loads, 20 ̊C ambient temperature, usual start stop cycles per hour and 8 hours
working per day
- 10 cycles for P series
- 50 cycles for all other series
Driving machine factor takes account the unbalanced working effects of combustion engines
Driving machine factor
Electric and hydraulic motors
1
Combustion engines with 4 cylinders or more
1.25
Combustion engines from 1 until 3 cylinders
1.5
Maximum torque of gearbox is torque, which can only be taken by static load. It should never be exceeded
during working.
Peak torque factor takes the amplitude of to gearbox applied torque
Peak torque factor
Load peaks per hour
Steady direction of load
Alternating direction of load
1-5
6-30
31-100
100<
2
1.5
1.4
1.2
1.4
1.1
0.9
0.8
Peak torque factor
Peak torque of machine
Nominal torque
Efficiency of
one stage
Max. transmission
ratio of one stage
Helical Gear
Bevel gear
Worm gear
98 - 99 %
97 – 98%
50 – 90 %
Helical Gear
Bevel gear
Worm gear
7
5
100
Static irreversibility:
Worm
For static irreversibility by driving from worm wheel, it should be:
Worm wheel
Coefficient of
static friction
2α
Static efficiency of worm gear
Static irreversibility can not be assured by driving from worm
Dynamic irreversibility:
Static irreversibility can be overridden with dynamic load
On the catalogues given efficiencies can be used for dynamic irreversibility, static
irreversibility can be calculated with angle values on the catalogues
Dynamic efficiency of worm gear
Transmission ratio i of spur gear
Transmission ratio
Input speed
Output diameter
Number of teeth of
input gear
Output speed
d1
d2
Input diameter
Transmission ratio of worm gear
Transmission ratio of planet gear while input sun gear and output carrier
Transmission ratio of several stages:
Transferred heat
energy
On catalogues given values for thermal power
is motor power, which can be chosen with a
certain heat exchanger.
Efficiency of gearbox
On catalogues given values for thermal power
is motor power, which can be chosen without
extra cooling equipment.
Planetary gear units without external cooling can
be selected if
Planetary gear units with heat exchanger can be
selected if
Required power
Required power
Lubrication factor
Factor for altitude
Cooling factor
Lubrication factor
Cooling factor
Factor for altitude
Cooling factor
Cooling Factor t1
Operation cycle per hour (ED) in %
100
80
60
40
20
…
…
…
…
…
Selection factors
Lubrication factor
Lubrication Factor t4
Mounting Position
Dip Lubrication
Expansion tank
…
M1
…
…
…
…
…
…
…
Factor for altitude
Factor for Altitude
Cooling system
Altitude above MSL
<1000m
<2000m
<3000m
<4000m
<5000m
…
…
…
…
…
Wind velocity factor
…
Output torque
D
Overhung load
Radial forces negligible
13
21
30
Low speed, low load
at least 13 teeth
Moderate speed (up to 6 m/s)
at least 17 teeth
Moderate load, up to 15 m/s
at least 21 teeth
High speeds, high load
at least 30 teeth
Number of teeth
Fe
Representative of real force
Fqe
u
y
L/2
L
We provide t, y and L values in the catalogue
Staring time of electric motor depends on moment of inertia
To shorten the starting time motor current should be higher
In some cases this brings motor failure because of heat
Therefore bigger motor has to be used
But this time it brings more peak torques to gearbox
As prevention a higher service factor has to be chosen or a hydraulic coupling , so more
powerful motor can be used
3-Phase asynchrony motor
M : Starting torque
A
M : Pull-up torque
S
M : Pull -out torque
K
M : Motor rated torque
N
M : Load torque
L
M1
M6
M4
M2
M5
M3
M1
Mounting position has
to be mentioned with
order
M6
Oil quantity and the
place of vent plug
depends on mounting
position
M4
M2
M5
M3
Poz.1 (Position 1 )
Poz.4 (Position 4 )
Poz.2 (Position 2 )
Poz.3 (Position 3 )
Poz.1 (Position 1 )
Poz.4 (Position 4 )
Poz.2 (Position 2 )
Poz.3 (Position 3 )
Poz.1 (Position 1 )
a
Poz.4 (Position 4 )
Poz.2 (Position 2 )
Poz.3 (Position 3 )
Nearest state to vertical axis (a) is Poz.1
Position is according to viewing behind motor.
●
Symbol
■
●
Meaning
Drain plug
Filling plug
Vent plug
Oil Level
■
●
●
■
■
Synthetic Oil
Mineral Oil
Oil Type
Mineral Grease
Synthetic
Grease
Usage Temperature at Dip
Lubrication
Usage Temperature at Forced
Lubrication
ISO Viscosity
0 - +100 ̊C
-
ISO VG 680
0 - +100 ̊C
-
ISO VG 460
0 - +100 ̊C
+15 - +100 ̊C
ISO VG 320
0 - +100 ̊C
+10 - +100 ̊C
ISO VG 220
0 - +100 ̊C
+5 - +100 ̊C
ISO VG 150
0 - +100 ̊C
+3 - +100 ̊C
ISO VG 100
-20 - +140 ̊C
-
ISO VG 680
-20 - +140 ̊C
-
ISO VG 460
-20 - +140 ̊C
+5 - +140 ̊C
ISO VG 320
-20 - +140 ̊C
0 - +140 ̊C
ISO VG 220
-20 - +140 ̊C
-5 - +140 ̊C
ISO VG 150
-20 - +140 ̊C
-8 - +140 ̊C
ISO VG 100
-20 - +120 ̊C
-
-
-30 - +100 ̊C
-
-
- Do not mix mineral oil to synthetic oil
- Depending on mounting position oil quantities varies
- Some gears splashes lubrication fluid upper parts of gearbox
- Oil change for mineral oil 10000 operation hours, for synthetic oil 20000 operation hours
(life time) no oil change required
- Gearboxes, which haven’t got any expansion space for the oil, should be used with
expansion tank
2 RS Bearing
Nominal power given
depending on input speed
Gearbox candidate selection according to output
torque and transmission ratio
Once speed is decided,
gearbox candidate can be
selected according to
motor power
Efficiency of gearbox has to be calculated
Efficiency of gearbox is
directly given if it is a low
efficiency product (E) or
has an importance (P,R)
Service factor has to be
calculated
Thermal power is given if
it is a low efficiency
product (E) or power
dense product (H, B, P, R,
Y)
Service factor of gearbox is directly given
If the termal power is not shown on the performance
tables, the service factor is given with consideration of
thermal power (EV Series). High efficient gearboxes
performance tables does not have thermal power
because their thermal power is higher then their
nominal power on normal condition (M, D, K).
DC Motors
AC Motors
3 Phase
Asynchrony
Motors
Synchronous Motor
1 Phase Asynchrony
Motors
Self Excited
Separately Excited
Series Wound
Shunt Wound
Compound Wound
Body material:
Aluminum for small motor sizes; Cast iron for bigger motor sizes
Power factor cos(ρ):
Increases with increasing of nominal motor power
Decreases with decreasing motor load
Nominal Power:
Output power of motor running on label frequency and voltage under full load
Number of pole and speed (50 Hz)
2 poles
~2800 rpm
4 poles
~ 1400 rpm
6 poles
~ 900 rpm
8 poles
~ 750 rpm
Calculating
Efficiency Values of
Motors with 4 Poles
Efficiency Classes
IE1
IE2
EFF2
EFF1
Standard Efficiency
A=0.5234
B=5.0499
C=17.4180
D=74.3171
High Efficiency
A=0.0278
B=1.9247
C=10.4395
D=80.9761
IE3
-
Premium Efficiency
A=0.0773
B=1.8951
C=9.2984
D=83.7025
IE4
-
Super Premium Efficiency
-
Nominal Efficiency
After 01-01-2015 only IE3 and IE2 with frequency inverter
Since 16-06-2011 only IE2
Nominal Load
Direct Motor Connection
B5 Flange
B14 Flange
B14 flange diameter on
motor side is smaller then
B5 flange diameter
With direct motor connection minimum length of geared motor
With flange easy change of motor
Approximated Brake Selection
Nominal motor
power
Nominal brake
torque
Safety coefficient > 2
Maximum motor speed
Thermal Capacity of Brake
Total inertia
reduced
to the motor shaft
Heat
dissipation energy
1
Static load torque stimulates the rotation of
motor
2
Static load torque opposes the rotation of motor
3
Static load torque opposes or stimulates rotation
of motor
Static load torque
Adjustment of the air gap:
In order to obtain the same performance from the brake the air-gap of the brake
must be re-adjust after a limited time of operation
When working place is humid,
Or manufacturing process needs a cleanroom
without oil vapor
Or the gearbox has to be filled fully with oil
Total volume of oil
Difference between
operation and ambient
temperature
Volume of expansion in
operation
Volume of expansion tank
Axial load while working
Torque, which has to be
look up from tables
Torque, which has to be
transferred
Inner diameter of coupling