Incremental bearing-free rotary encoder – GEL 2471

1-/2-channel inductive speed sensor for electrically conductive target wheels

Maintenance- and wear-free speed sensor using inductive scanning
Scanning of measuring scales (for example, target wheels made of electrically conductive materials)
Reliable detection of high rotational speeds to creeping (0 Hz to 20 kHz)
Most reliable direction of rotation detection by evaluating two channels
Robust and compact stainless steel housing for use in harsh and confined applications

Inquiry & Support

Technical information

Properties

Incremental, magnet-free 1-/ 2-channel speed sensor based on the eddy current principle
Highest signal quality for reliable evaluation in control systems
Robust stainless steel housing with a sensor tube;diameters of 16 mm and 20 mm available
High EMC immunity for interference-free signal transmission in challenging industrial environments
Configuration flexibility thanks to freely selectable cable outlet, cable protection, and connector variants
In accordance with a range of standards and requirements for a variety of applications:
Technical data - Environmental test

Advantages

Optimized lifecycle cost
Maintenance and wear-free
Various configuration options
Compact and robust design
Reinforced walls in the sensor tube with a diameter of 20 mm provide increased protection against the impact of stones and foreign bodies
No adhesion and accumulation of magnetizable particles on the sensor head
Weight reduction when using aluminum measuring scales
Easy to assemble
Simple integration
High signal quality

Downloads

Product	Document	Languages
GEL 2471	Technical information	DE EN CN
GEL 2471	Product information*	DE/EN

Registration required

Fields of application

Industry and automation

Printing and packaging machines:

Synchronization of conveyor belts
Register control during printing

Automotive and commercial vehicles

Vehicle drives:

Speed measurement on crankshafts and camshafts for engine control units
Determination of rotor position in electric motors (BLDC, PMSM)
Input/output speed in gears for gear change strategy

Vehicle movement dynamics systems:

Wheel speed sensors for ABS/ESP
Torque distribution in all-wheel drive systems

Commercial vehicles and agricultural machinery:

Speed monitoring on PTO shafts, hydraulic pumps
Harvesting machinery: Worm conveyors, threshing drums

Railroad technology and transportation

Rail vehicles:

Wheel speed sensors for traction control and brake control
Drive control for electric locomotives and railcars

Conveyor belts and cable cars:

Speed monitoring on deflection pulleys
Drive synchronization in multi-motor systems

Maritime applications

Drive:

Speed measurement on marine engines, turbochargers, gearboxes, and generators

Auxiliary units:

Input/output speed detection for slip control

Energy and utilities

Wind turbines:

Rotor speed for power control
Pitch adjustment (rotor blade angle control)

Hydropower plants/turbines:

Speed control for synchronization with mains frequency

Generators and emergency power systems:

Speed detection for frequency monitoring and load management

Building technology and infrastructure

Elevators and escalators:

Speed and position of the car
Safety systems (emergency stop in case of overspeed)

Building machinery:

Pump and fan speeds in large HVAC systems

Logistics and conveyor technology

Conveyor belts:

Speed control in distribution centers

Automatic storage systems:

Positioning of rack feeders

Crane systems:

Lift and undercarriage control

Dimensional drawings

Cable outlet straight

Cable length L is determined by type code

Cable outlet at side

Cable length L is determined by type code

All dimensions in mm [inch]

Technical data

Display of signal patterns

Signal pattern E-

1 channel

Signal pattern S-

1 channel with directional signal

Signal pattern V-

2 channels, 90° phase offset

Signal pattern X-

2 channels, 90° phase offset, with inverse channels

Signal pattern	E-	V-	X-
Electrical data
Supply voltage U_B (reverse polarity protected)	10 to 20 V DC (10 to 30 V DC upon request)
Current consumption I_B (without load)	≤ 40 mA
Output signal (short-circuit-proof)	Square-wave signals
Output signal level High	≥ U_B- 1.8 V
Output signal level Low	≤ 1.5 V
Output current per channel	≤ 20 mA
Frequency range	0 to 25 kHz
Duty cycle	50% ± 20%
Phase offset	-	typ. 90°
Mechanical data
Sensor tube material	Stainless steel
Flange material	Stainless steel
Sensor weight (incl. 2 m cable)	500 g
Cable data
Cable	halogen-free and screened
Cable diameter	5.4 ± 0.2 mm		6.5 ± 0.3 mm
Cable cross section	4 × 0.5 mm²		6 × 0.5 mm²
Minimum bending radius static/dynamic	16 mm/27 mm		20 mm/33 mm
Environmental tests
The speed sensor complies with a range of standards and requirements for a variety of applications: Technical data - Environmental test
Requirements for the target wheel
Material	Steel, aluminum (others upon request)
Tooth form	Involute gear teeth according to DIN 867 Square gear teeth 1:1 or slotted disk (upon request)
Width	≥ 10 mm (smaller upon request)
Module m	2.00/2.25/2.50/2.75/3.00*
Nominal air gap	0.7 mm at ± 0.3 mm maximum permissible radial runout

Environmental test

	Rail vehicle industry	Maritime applications	Industrial applications
Working and operating temperature	-40 °C to +120 °C
Storage temperature	-40 °C … +120°C
General industry standard	DIN EN 50155:2022-06	DNV-CG-0339	depending on the application
Dielectric strength	500V AC / 750V DC DIN EN 50155:2022-06	DNV-CG-0339	500V AC
Electromagnetic compatibility	DIN EN 50121-3-2:2017-11	DNV-CG-0339	IEC 61000-6-2:2016 IEC 61000-6-4:2016
Vibration resistance	DIN EN 61373:2011-04 Cat. 3	DNV-CG-0339	IEC 60068-2-64:2008 IEC 60068-2-6:2008
Shock resistance	DIN EN 61373-2011-04 Cat. 3	DNV-CG-0339	IEC 60068-2-27:2008
Fire protection	DIN EN 45545-2:2023-12 NFPA 130 upon request	IMO 2010 FTP	upon request
Degree of protection on measuring side	IP68
MTTF value	2,000,000 at 55 °C