Kübler Elevator Products
Absolute encoders for direct drives
LM Mechanical Lift System
Fritz Kübler GmbH Zähl-und Sensortechnik’s LM 3 and LM 5 are preassembled elevator systems for shaft-copying, designed with bearings to make a significant contribution toward increased safety and reliability in lift technology. The units also feature a vibration-resistant encoder-mounting fixture and smooth-running toothed belt to provide less noise in the shaft. The products’ Sendix encoders control the rotational speed and drive position, and are designed to offer accurate shaft copying and monitor the speed limiters. Their features include high resistance to shock and vibration, high protection level of up to IP67 and wide temperature range (-30°C to +85°C).
The mechanical loading an encoder experiences within lifting mechanics is quite considerable. Here, Kübler’s prefabricated LM lift systems separate the load and sensor technology and protect the encoder with the aid of additional bearings outside the encoder, while relieving the load on the encoder bearings.
Sendix SSI/BiSS absolute encoders with additional sine/cosine output and Sendix incremental encoders in sine/cosine versions are now available with SIL3/PLe certification. Sendix SIL absolute encoders obtain absolute-position information, and the controller counts the incremental pulses and compares the result with the absolute position. In contrast, with Sendix SIL incremental encoders, the controller monitors the validity of the analog 90° phase-shifted sine/cosine signals with the help of the function sin2 + cos2 = 1. As the mean-time-to-dangerous-failure values for Kübler’s most important standard encoders are provided, the user may carry out his or her own calculations according to DIN EN 61800-5-2 and DIN EN ISO 13849.
Encoders for Direct Drives
Kübler mounts its absolute single-turn (up to a maximum 17 bits) encoders on gearless (direct) drives. A torque stop facilitates quick mounting, and a zero-point “Set” button allows a fast start-up. Manufacturers of gearless lifts can use these products to reduce assembly work, as easy installation is possible due to the encoder’s tapered shaft for a high-accuracy direct coupling to the direct drive; the tapered shaft is fastened onto the drive shaft by a central tightening screw.
Sendix Absolute Encoders with CANopen Lift Interface
Sendix encoders with CANopen lift interface are available in single- and multi-turn versions, with removable bus terminal covers for optimal integration in complex controller-area networks (CANs) or with fixed connections (including directly with a SUB-O connector). The CANopen Lift interface (Profile OS 417 Vl.1) allows a particularly simple implementation of the lift control with the following functions:
- Car position unit
- Two virtual devices, one each for the position in absolute measuring steps and the position as absolute displacement information in mm
- Lift number programmability
- Independent setting of the node address in conjunction with the CAN identifiers
- Factor for speed calculation (e.g., measuring wheel circumference)
- Integration time for speed value from one to 32
- Two working areas with two upper and lower limits: corresponding output states extended error management for position sensing with integrated temperature control.
- Process-data-object mapping of variables in the memory: whether position, speed, acceleration or working area, the user decides which information is available in real time.
Diagnoses can be run via the aforementioned “Set” button and an LED interface. Node addresses and baud rates can be adjusted by means of rotary/dual-in-line-package switches or software.
Sendix absolute CANopen field-bus encoders are also available with an additional transistor-transistor logic (TTL) incremental track. This allows simultaneous positioning via the CAN network with one encoder and a direct rotary speed feedback via the incremental track. This saves finding the installation space for a second encoder. In parallel with the CANopen output, the encoder delivers an additional TTL-compatible signal with 204B pulses per revolution. For that purpose, the encoder is also equipped with an RS 422 interface.
For more information, contact Kübler at Schubertstrasse 47, D-78054 Villinger-Schwenningen, Germany; phone: (49) 0-7720-39030; fax: (49) 0-7720-21564; e-mail: firstname.lastname@example.org; or website: www.kuebler.com