Absolute Value Angular Measuring System
for Machine Tools
Direct integration in precision bearings
for rotary axes
Direct integration in precision bearings for rotary axes
Absolute value angular measuring system for machine tools
■ the facility for highly dynamic and
The binary value obtained, which occurs
only once per angular position within the
precise control loops
■ savings in terms of design envelope
■ simplifications in design and
entire measurement range, is converted
into an absolute angular value by
a microcontroller using a conversion
mounting
table.
0008F2C2
■ resistance to environmental
Figure 1: Absolute value angular measuring system
comprising:
axial/radial bearing YRTMA or YRTSMA
and measuring head MHA
influences, lubricants and cooling
The electronic evaluation system is
lubricants.
integrated in the measuring head,
so the system can be connected directly
The inductive measurement
to the controller. Technical data:
method ABSYS (AMO) is based on
see Table 1 (other designs available by
contact-free scanning of a structured
agreement).
dimensional scale that is applied
directly as a measurement ring to
The ideal location for mounting
a measuring system is directly in the
bearing arrangement, which means
that higher system accuracies can be
achieved with measuring systems
the bearing inner ring. The irregular
structure with absolute coding is
captured on a bitwise inductive basis
by a coil arrangement that is integrated
in the measuring head, Figure 2.
integrated in the bearing than with
measuring systems that are attached
to the axis a significant distance from
the relevant bearing arrangement.
The very high radial runout of the high
precision rotary axis bearing YRT(S)MA
is utilised here.
Bit “0“
Bit “1“
Secondary windings
Primary windings
Bit “n“
cos
sin
The absolute angular measuring system
Sensor substrate / microcoils
sin
cos
Absolute scanning
Incremental scanning
Pitch with absolute
coding
integrated directly in the bearing,
Figure 1, offers considerable
■ an absolute interface, dispensing
Dimensional scale
(measurement ring)
with the need for reference travel
Pitch with incremental coding
■ a hollow shaft design, freeing up
the centre of the machine for other
components
Figure 2: Functional principle of inductive scanning
00093210; source: AMO
advantages:
The measuring head that is used to scan
the dimensional scale, is designed such
that it can be screw mounted directly
Table 1: Integrated electronic measuring system
Data
Specification
Comments
Pitch period
1000 m
–
Absolute resolution
10 bit/pitch period
SSI +1Vss
12 bit/pitch period
DRIVE-CLiQ and FANUC
Electrical interface
SSI +1 VSS
DRIVE-CLiQ
FANUC alpha
EnDat 2.2 and FANUC alpha i
in preparation
Supply voltage
DC 5 V 5%
SSI +1 VSS
FANUC
to the stationary bearing outer ring and,
without adjustment, has the correct air
gap relative to the measurement ring.
The measuring head is easily accessible
DC 24 V 5%
DRIVE-CLiQ
Current consumption
max. 250 mA
at DC 5 V
Operating temperature
from –10 °C to +85 °C
–
Storage temperature
from –20 °C to +85 °C
–
Protection to DIN EN 60529
IP68
Radial measuring head
Electrical connection to measuring head
M23 plug connector,
17 pin, pin
SSI +1Vss
ing head and cable can also be fitted
M23 plug connector,
8 pin, pin
FANUC
after the bearing has been mounted.
M12 plug connector,
8 pin, pin
DRIVE-CLiQ
1m
SSI +1 VSS
FANUC
0,5 m
DRIVE-CLiQ
from outside, Figure 3, and can be
fitted or replaced without additional
adjustment work.
Due to this design solution, the measur-
The risk of damage as a resulting of
Cable length and diameter
mounting operations is thus substantially eliminated. A circumferential
seal on the measuring head protects
the raceway area of the bearing from
the environment.
Dimensions and characteristics
The absolute value angular measuring
system is available in the bearing size
range YRT(S)MA200 to YRT(S)MA460,
see dimension tables. Other sizes are
0007FD38
available by agreement.
Figure 3: Easy-to-mount rotary table assembly with axial/radial bearing YRT(S)MA,
easily accessible measuring head, no adjustment of measurement gap in fitting or replacement
Achievable accuracies
The axial and radial runout tolerances
Table 2: Axial and radial runout of axial/radial bearings YRTMA and YRTSMA
Bore
d
are measured on the mounted bearing,
YRTMA
Pitch accuracy
The pitch accuracy gives information
on the accuracy of the coded structure
on the measurement ring.
Extremely high pitch accuracies are
YRTSMA
Normal2)
Restricted2)
Normal2)
Restricted3)
mm
m
m
m
m
200
4
2
4
2
260
6
3
6
3
325
6
3
6
3
395
6
3
6
3
460
6
3
6
3
with an ideal adjacent construction,
see Table 2.
Axial and radial runout 1)
t1
1) Measured on mounted bearing, with ideal adjacent construction.
2) For rotating inner and outer ring.
3) For rotating inner ring only.
achieved in the bearing size range
from YRTMA200 to YRTMA460,
see Table 3.
Table 3: Angular resolution and pitch accuracy
Designation
Angular resolution
Incremental
Pitch accuracy
Pitch periods/360°
1)
YRTMA200, YRTSMA200
860
4,5
YRTMA260, YRTSMA260
1088
3,6
YRTMA325, YRTSMA325
1302
3
YRTMA395, YRTSMA395
1530
2,5
YRTMA460, YRTSMA460
1760
2,2
1) Angular seconds.
Positional accuracy
In practical tests, a conventionally
In contrast, the comparative measure-
The positional accuracy in accordance
flange mounted measuring system was
ments showed that the bearing-
with VDI DGQ Guideline 3441 signifies
compared with the bearing-integrated
integrated absolute value angular
the precision with which it is possible
measuring system YRTMA, where both
measuring system can achieve higher
to position the complete driven axis,
systems have the same pitch accuracy
positional accuracy than the measuring
comprising the measuring system,
according to the manufacturer’s test
system installation described above.
rotary table bearing arrangement,
certificate. Figure 4 shows the positional
The comparison proves that direct
drive system, controller and positional
accuracy of a flange mounted measure-
integration in the bearing gives a further
control. The actual position of the axis
ment ring that must be mechanically
significant improvement in positional
under control is recorded in measure-
centred at the time of mounting.
accuracy as a result of the very high
ment of the positional accuracy by
The influence of the radial runout devi-
machining quality of the rotary table
means of a laser autocollimator that
ation on the measurement error can be
bearing components, Figure 5.
calculates the nominal position and
seen. The accuracy achieved in this case
then determines the positional
is satisfactory for many applications.
deviation.
5
4
5
4
Positive reversal range
Positional deviation from nominal value
3
Positive positional scatter
2
1
0
Systematic
deviation from
nominal value
–1
–2
–3
Negative reversal range
–4
Negative positional scatter
–5
0
30
60
90 120 150 180 210 240 270 300
Measurement position
° 360
Figure 4: Typical positional accuracy of a rotary table
with a flange mounted measuring system and mechanically centred
measurement ring, measured at the workpiece clamping plate
00093222
00093219
Positional deviation from nominal value
3
Positive reversal range
Positive positional scatter
2
1
0
–1
Negative reversal range
–2
Negative positional scatter
Systematic
deviation from
nominal value
–3
–4
–5
0
30
60
90 120 150 180 210 240 270 300
Measurement position
Figure 5: Typical positional accuracy of a rotary table
with a bearing-integrated measuring system YRTMA325,
measured at the workpiece clamping plate
° 360
D
J1
D1
J
0009183B
Axial/radial bearings
Double direction
With measuring system
d1
B
d3
t1 D
t1 C
D
C
t1 B
a
d
DM
H
H2
C
d2
H1
A
t1 A
YRTMA
Dimension table · Dimensions in mm
Designation
Mass
Dimensions
Fixing holes
Inner ring
m
d
D
H
H1
H2
C
D1
DM
6)
Outer ring
J
J1
d1
d2
a
Quantity7)
d3
Quantity7)
⬇ kg
YRTMA200
10,7
200
300
516)
30
216)
15
274
274,4
215
285
7
11
6,2
46
7
45
YRTMA260
18,7
260
385
57,56)
36,5
216)
18
345
346,9
280
365
9,3
15
8,2
34
9,3
33
YRTMA3258)
25
325
450
616)
40
216)
20
415
415,1
342
430
9,3
15
8,28)
34
9,3
33
YRTMA395
33
395
525
65
42,5
22,5
20
486
487,7
415
505
9,3
15
8,2
46
9,3
45
YRTMA460
45
460
600
70
46
24
22
560
560,9
482
580
9,3
15
8,2
46
9,3
45
Further information on axial/radial bearings: see TPI 120, High Precision Bearings for Combined Loads.
Including retaining screws or threaded extraction holes.
2)
Tightening torque for screws to DIN EN ISO 4762, grade 10.9.
3)
For high operating durations or continuous operation, please contact us.
4)
Measurement speed nconst = 5 min–1.
5)
The rigidity values take account of the rolling element set,
deformation of the bearing rings and the screw connection.
6)
Dimension differs from the axial/radial bearing YRT.
7)
Attention!
For fixing holes in the adjacent construction.
Note the pitch of the bearing holes.
8)
Screw counterbores open to the bearing bore.
Bearing inside diameter unsupported in the area �.
000870FA
1)
2
Screw counterbore in YRTMA325 open,
bearing inside diameter unsupported in area �
00091850
00091847
2M6
1
2M6
n
t
120
°
2
G
1
Measuring head suitable for radial screw mounting
� Shaft locating washer; � Inner ring
Pitch1)
Threaded
extraction holes
Tightening
torque2)
nt
Hole pattern, measuring head suitable for radial screw mounting
� Two retaining screws
Basic load ratings
axial
G
Quantity
Limiting
speed3)
radial
Bearing
frictional
torque4)
Vertical rigidity5)
axial
radial
Tilting
rigidity
MA
dyn.
C
stat.
C0
dyn.
C
stat.
C0
nG
MR
caL
crL
ckL
Nm
N
N
N
N
min–1
kNm/mrad
Nm
kN/m
kN/m
487,5°
M8
3
14
98 000
650 000
89 000
236 000
170
15
3
3,5
23
3610°
M12
3
34
109 000
810 000
102 000
310 000
130
25
3,5
4,5
45
3610°
M12
3
34
186 000
1 710 000
134 000
415 000
110
48
4,3
5
80
487,5°
M12
3
34
202 000
2 010 000
133 000
435 000
90
55
4,9
6
130
487,5°
M12
3
34
217 000
2 300 000
187 000
650 000
80
70
5,7
7
200
D
J1
D1
J
00091859
Axial/radial bearings
Double direction
With measuring system
d1
B
d3
t1 D
t1 C
D
C
t1 B
a
d
DM
A
H
H2
C
d2
H1
t1 A
YRTSMA
Dimension table · Dimensions in mm
Designation
Mass
Dimensions
Fixing holes
Inner ring
m
d
D
H
H1
H2
C
D1
DM5)
J
J1
d1
d2
Outer ring
a
Quantity6)
d3
Quantity6)
⬇ kg
YRTSMA200
10,7
200
300
515)
30
215)
15
274
274,4
215
285
7
11
6,2
46
7
45
YRTSMA260
18,7
260
385
57,55)
36,5
215)
18
345
346,9
280
365
9,3
15
8,2
34
9,3
33
YRTSMA3257)
25
325
450
615)
40
215)
20
415
415,1
342
430
9,3
15
8,27)
34
9,3
33
YRTSMA395
33
395
525
65
42,5
22,5
20
486
487,7
415
505
9,3
15
8,2
46
9,3
45
YRTSMA460
45
460
600
70
46
24
22
560
560,9
482
580
9,3
15
8,2
46
9,3
45
Further information on axial/radial bearings: see TPI 120, High Precision Bearings for Combined Loads.
Including retaining screws or threaded extraction holes.
2)
Tightening torque for screws to DIN EN ISO 4762, grade 10.9.
3)
For high operating durations or continuous operation, please contact us.
4)
The rigidity values take account of the rolling element set,
deformation of the bearing rings and the screw connection.
5)
Dimension differs from the axial/radial bearing YRT.
6)
Attention!
For fixing holes in the adjacent construction.
Note the pitch of the bearing holes.
7)
Screw counterbores open to the bearing bore.
Bearing inside diameter unsupported in the area �.
000870FA
1)
2
Screw counterbore in YRTSMA325 open,
bearing inside diameter unsupported in area �
00091850
00091847
2M6
1
2M6
n
t
120
°
2
G
1
Measuring head suitable for radial screw mounting
� Shaft locating washer; � Inner ring
Pitch1)
Threaded extraction Tightening
holes
torque2)
nt
Hole pattern, measuring head suitable for radial screw mounting
� Two retaining screws
Basic load ratings
axial
G
Quantity
Limiting
speed3)
radial
Vertical rigidity4)
axial
radial
Tilting
rigidity4)
MA
dyn.
C
stat.
C0
dyn.
C
stat.
C0
nG
caL
crL
ckL
Nm
N
N
N
N
min–1
kN/m
kN/m
kNm/mrad
4
1,2
29
487,5°
M8
3
14
155 000
840 000
94 000
226 000
1 160
3610°
M12
3
34
173 000
1 050 000
110 000
305 000
910
5,4
1,6
67
3610°
M12
3
34
191 000
1 260 000
109 000
320 000
760
6,6
1,8
115
487,5°
M12
3
34
214 000
1 540 000
121000
390 000
650
7,8
2
195
487,5°
M12
3
34
221 000
1 690 000
168 000
570 000
560
8,9
1,8
280
Measuring head
700,1
JM
Suitable for radial screw mounting
1
2
R25
00091862
HM
R12
MHA
� Measuring head; � Measurement ring
Dimension table · Dimensions in mm
Designation
Electronic interface
Plug connector
Thread
Cable length
Pins
Mass
Dimensions
m
D
m
⬇ kg
MHA200-0-0
SSI +1Vss
M23
17 pin
1
0,228
MHA200-0-2
DRIVE-CLiQ
M12
8 pin
0,5
0,129
MHA200-0-3
FANUC
M12
8 pin
1
0,144
MHA200-0-5
EnDat 2.2
M12
8 pin
1
0,144
MHA260-0-0
SSI +1Vss
M23
17 pin
1
0,252
MHA260-0-2
DRIVE-CLiQ
M12
8 pin
0,5
0,153
MHA260-0-3
FANUC
M12
8 pin
1
0,168
MHA260-0-5
EnDat 2.2
M12
8 pin
1
0,168
MHA325-0-0
SSI +1Vss
M23
17 pin
1
0,248
MHA325-0-2
DRIVE-CLiQ
M12
8 pin
0,5
0,149
MHA325-0-3
FANUC
M12
8 pin
1
0,164
MHA325-0-5
EnDat 2.2
M12
8 pin
1
0,164
MHA395-0-0
SSI +1Vss
M23
17 pin
1
0,246
MHA395-0-2
DRIVE-CLiQ
M12
8 pin
0,5
0,147
MHA395-0-3
FANUC
M12
8 pin
1
0,162
MHA395-0-5
EnDat 2.2
M12
8 pin
1
0,162
MHA460-0-0
SSI +1Vss
M23
17 pin
1
0,257
MHA460-0-2
DRIVE-CLiQ
M12
8 pin
0,5
0,158
MHA460-0-3
FANUC
M12
8 pin
1
0,173
MHA460-0-5
EnDat 2.2
M12
8 pin
1
0,173
JM
HM
T
0,1
300
19
49
163,2
385
33
52
205,7
450
39
54
238,2
525
34
54
275,7
600
39
56
313,2
D
1
30
2
� Measuring head; � Measurement ring; � Inner ring of axial/radial bearing
000918AC
3
T
MATNR 081834578-0000 / SSD 30 / 03 / GB-D / 201509.5 / Printed in Germany by wünsch
Your contact
Dipl.-Ing. (FH) Günter Schmid
Telephone +49 9132 82-2392
[email protected]
Schaeffler Technologies
AG & Co. KG
Industriestraße 1–3
91074 Herzogenaurach
Germany
www.schaeffler.com
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