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Minicoder Absolute Gel 2800
The new MiniCODER-
ABSOLUTE multi-talent for hollow shaft drives
Innovative, absolute measuring MiniCODER
Absolute position acquisition with magnetic measuring system
Scalable, for shaft diameters up to 500 mm
Little space required for the scanning unit
Easy installation
ABSOLUTE sensor technology for modern motors
New scalable magnetic absolute encoder kit eases the adaptation to the
diameter of the shaft on drive systems
On electrical drives and servomotors, the precise acquisi
tion of the rotor position for the control of the motor plays
a crucial role. Currently, optical sensors are primarily used
for this task; in critical application environments these
sensors have significant disadvantages. Oil, water and
dust significantly degrade the measurements. This is not
the case with magnetic sensors: due to its sensing princi
ple,the scanning unit can be fully encapsulated. This fea
ture makes it particularly robust and insensitive to soiling
in the measuring space. The metal measuring scales are
also extremely robust and are resilient to even heavy me
chanical shocks and vibration.
Up to now magnetic absolute rotary encoders have been
predominantly available on the market as rotary encoders
with integrated bearings. Above all the bearings used define
the service life of these systems, as the selection of
the bearing is dependent on the mechanical load, the op
erating temperature (grease selection) and the speed
range. However, these aspects are heavily dependent on
the application.
For years there has been a trend in many sectors of indus
try to torque motors and high performance drives. Im
proved dynamic performance and precision, low wear and
the compact design are the main reasons for this development.
Such drives are primarily used in harsh industrial
environments - an ideal application area for magnetic
sensors.
The direct drives have diameters of up to a metre. In par
ticular in hollow shaft drives, considerable effort is re
quired to adapt rotary encoders with integrated bearings
to the diameter of the shaft in the related drive system.
The large amount of heat produced by the direct drives
also places high requirements on the rotary encoder's
bearings. This situation results in increased application
effort that is of considerable disadvantage particularly in
times of high levels of competition and rapid product
changes.
Against this background, Lenord + Bauer developed an
absolutely measuring encoder kit system. It does not re
quire an integrated bearing and its measuring scale can be
flexibly adapted to the shaft diameter. Lenord + Bauer al
ready has many years of experience in this area. The Mini
CODER is a prime example of the successful usage of en-
coder kits in highly dynamic systems such as high-speed
spindles.
Here the contactless encoder kit principle can exploit its
advantages to the full due to the compact design, the rota
tional speed measurement without bearings and the flexi
ble design of the measuring scale. Scanning unit and
measuring scale do come together until they are finally
installed in the application, for example on the drive. Giv
en careful design with precise mechanical components,
these systems achieve high overall accuracy. The new ab
solute encoder kit system is small, flexible, scalable and
cost-effective.
Absolute technology
A novelty in sensor technology
The new measuring unit comprises a magnetic absolute
single turn encoder kit and a ferromagnetic measuring
scale. The encoder system calculates the absolute position
via a vernier evaluation. The absolute rotary encoders
with integrated bearings from Lenord + Bauer are also
based on this principle. For this evaluation, two-track
measuring scales with different numbers of teeth or pulse
counts are required. The giant magneto-resistive (GMR)
sensors scan these two tracks contactlessly and provide
corresponding sinusoidal signals.
The phase position of the two sinusoidal signals in relation
to each other is evaluated based on the vernier principle.
The phase position is unambiguous within one turn
and in this way the system calculates the absolute position
with high resolution. The absolute position is available
immediately after switch on.
The GMR sensors are designed such that the characteristic
is very linear over a wide range. In combination with a high
accuracy measuring scale, the integrated geometric harmonic
filtering generates particularly low distortion sine
and cosine signals. The resistance of the elements is also
extremely low to ensure good EMC characteristics. With
these measures the system achieves accuracies of 12 to
14 bits.
The signals generated are evaluated in an ASIC developed in-house. Up to now it was only possible to evaluate measuring scales with binary number of segments (8/7, 16/15, 32/31). Due to the new vernier ASIC, almost stepless design of the measuring scale is achieved. As a result the new system can be scaled flexibly and adapted to the shaft diameter without major effort.
Absolute MiniCODER with new sensor technology
The new encoder kit acquires the absolute rotor position precisely and can
be flexibly adapted to any drive.
Absolute encoder kits are ideally suited to the acquisition
and feedback of the absolute rotor position to the motor
control system. With the new MiniCODER, Lenord + Bauer
is setting standards in absolute magnetic kit measuring
systems.
The design without bearings is extremely long-lived and
acquires the absolute position at rotational speeds up to
20,000 min-1. As such the new encoder kit can also be
used in highly dynamic drives. Dust, humidity and oil do
not affect the magnetic measuring system. This feature
makes the MiniCODER a specialist for harsh industrial environments.
Due to the modular construction the system covers a wide
range of shaft diameters, which significantly simplifies
adaptation to the motor.
The MiniCODER provides unambiguous position values at
any angular position via an SSI or BISS interface. There is
also an incremental signal for the rotational speed measurement.
The absolute position is available immediately
after switch on, which makes a reference search routines
unnecessary. Furthermore, the encoder kit undertakes a
self-calibration; in this way the measuring system is also
robust in relation to mechanical tolerances.
- Magnetic absolute encoder kit system with modular construction
- Resolution up to 17-bit single turn
- SSI or BISS interface
- Robust to mechanical tolerances
- Developed for use in harsh environmental conditions
- No effect on the measuring system due to magnetic brakes or motor winding
Technical data
| Absolute MiniCODER (single turn) | |
|---|---|
| Resolution per revolution | 8 to 17 bits |
| Absolute accuracy | 0.1º |
| Incremental output pulses per turn | Can be defined according to customer specifications |
| Rotational speed measuring range | 0 to 20,000 min-1 |
| Housing dimension | 52 x 22 x 16 mm |
| Protection class | IP 68 |
| Temperature range | -40 to +105 ºC |
| Supply voltage | 10 to 30 V DC |
| Interfaces | Absolute: SSI, BISS,Incremental output: A / A / B / B |
Target wheels - adapted flexibly and without effort
The new type of sensor evaluates two-track target wheels with shaft
diameters from 20 to 500 mm reliably and with high accuracy.
The flexibility of the encoder system permits rapid adaptation
to changing operating conditions, and that with little
effort. Without major printed circuit board modifications
or high initial effort, the encoder system can be integrated
into the required application by adapting the measuring
scale. The robust target wheel made of ferromagnetic steel
is mounted directly on the drive shaft without an integrated
bearing.
As standard the new GMR sensors evaluate target wheels
with modules 1 and 2. However, larger modules are also
not a problem for the new system. They also deliver interpolated
signals with high accuracy in case of an extended
length tooth period. This feature makes the overall system
particularly flexible.
Due to the modular construction of the system, one sensor
can be used for different target wheel sizes. Shaft diameters
from 20 mm to 500 mm can be realised. The inside
diameter can be varied for the same outside diameter of
the measuring scale. Particularly for manufacturers of
customer-specific drives, component management is significantly
simplified.
- Long periods permit a larger air gap and deliver signals of high quality
- Flexible dimensioning of the target wheel in relation to inside diameter, outside diameter and number of teeth
- Optimised component management, one sensor for several target wheel sizes
- Easy installation / commissioning
Technical data
| Standard target wheels | |
|---|---|
| Shaft diameter | 20 to 500 mm |
| Module | 1; 2 (further modules upon request) |
| Teeth | Involute gear teeth |
| Air gap | 0.4 mm for module 1 / 0.7 mm for module 2 |
| Material | Ferromagnetic steel |
| Maximum rotational speed | 20,000 min-1 |
One sensor for different compact hollow shaft drives
The desire from machine manufactures for increasing performance and
more compact design led to the development of new hollow shaft drives at
Harmonic Drive AG. The newly-designed absolute encoder kits from Lenord
+ Bauer make integration in different sizes particularly easy.
To be able to trade successfully on the global market, industrial
organisations are demanding ever more compact
and economical machinery and plants. The manufacturers
of drive systems are also subject to this pressure. As the
drive technology and the control system technology in
particular have a significant affect on the investment costs
for the operating company. However, the performance of a
machine is also defined to a significant degree by these
core components.
The trend in drive technology is toward space and weightsaving,
highly geared down and therefore compact products.
Today the demand is for compact and economical
drive solutions, comprising gear, motor, control system
and instrumentation. This demand is placing new challenges
on businesses. Here Harmonic Drive AG, as a
provider of drive systems and play-free gears, is treading
new ground.
In the digital AC hollow shaft drives of its CHA series, Harmonic
Drive AG combines precise gears with highly dynamic
AC motors. These precision servo drives are used
for positioning in demanding industrial applications that
require accuracy, compactness and high torque. In relation
to the sensor technology, this means the technology
must supply highly precise, absolute position values and
be flexible.
In the CHA-14A and CHA-17A hollow shaft drives, powerful
CPU-M gear units are perfectly combined with newly developed,
highly dynamic servomotors. High resolution,
magnetic absolute rotary encoders from Lenord + Bauer
are used in this series. A unique feature of the drives is the
central hollow shaft that can be used to carry supply lines,
shafts or even laser beams through the middle of the
drive. This property significantly simplifies the design in
many applications and in this way saves time during development
and installation.
The series with a total of eight sizes covers a torque range
from 6.8 to 1840 Nm. Maximum rotational speeds of up to
283 min-1 ensure the highest dynamic performance and
processing times. The CHA series is also extremely well
suited to high-precision positioning tasks due to freedom
from play and the integrated, highly precise absolute rotary
encoders from Lenord + Bauer.
Above all in machine tools, the drives must be equipped
with a hollow shaft and feature high resilience and a high
protection class, as well as absolute, precise positioning
without referencing. Drives for the fourth and fifth axis on
the machining head in particular also require a rigid output
bearing arrangement for mounting the tool directly.
Only in this way can a particularly compact design be
achieved for the milling heads, as well as water jet cutting
systems and laser cutting systems.
With the CHA series, Harmonic Drive AG also has the perfect
solution here. The CHA 14/17 servo drives are a further
development of the FHA-14C and FHA‑17C drive series
in use for many years. In the new small CHA servo drives,
the continuous torque is increased by around 50 percent.
In addition, the new servo drives with protection class IP
65 are extremely resilient and robust.
The integration of a holding brake, a resolver for usage in
harsh ambient conditions and the absolute multiturn encoder
kit with SSI, for use in machine tools among other
areas, are further advantages of the new drive generation.
In the drive design, Harmonic Drive AG places great value
on the functionality and longevity of its products. These
are also crucial factors for Lenord + Bauer. The new absolute
encoder kit impresses due to its flexibility and small
size. The sensor system is modified to the shaft system
without application effort. In this way one sensor can be
used for several shaft diameters, a real advantage in component
management.
The surfaces of the motor and gears are coated and protected
against corrosion. This feature makes the drives
particularly resilient. To protect the encoder kit, it is positioned
under the magenta cover on the rear. However, its
design also makes it extremely robust in relation to harsh
ambient conditions. With a resolution of 17 bits in a single
turn and an SSI or BISS interface, it provides the position
values in the required quality. Magnetic brakes or the motor
winding do not affect the values measured. For this
reason the absolute MiniCODER is particularly suitable for
direct mounting on motors or gears. It is a multi-talent for
almost any drive solution.
With the addition to the CHA series of hollow shaft drives
(CHA-20A to CHA-58A) of two further sizes (14 and 17), the
previous peak torque spectrum from 27 to 1840 Nm has
been extended downward. The new drive series offers significant
advantages for the user and addresses future and
continuously increasing market requirements.
As a technology leader in the area of high precision drive
technology - particularly highly geared down, play-free
and low play drive solutions - Harmonic Drive AG wants to
further expand its market leadership also in the coming
years. The advanced, scalable encoder kit system from
Lenord + Bauer will provide additional market opportunities
during this process due to the optimised component
management.
Drive AG
The core competence of Harmonic Drive AG is the development, manufacture and marketing of installation kits, gearboxes, servomotors, servo and special drives in various series and sizes. Here the organisation relies on innovative, technologically mature series production products as well as customised system solutions devised with customers and specifically tailored to their needs.
