see Axial force

Axial force is the force acting along the axis of a body. Drives with angled toothing produce axial forces as a reaction to the torque input. These forces are absorbed in the gearhead and do not act outwards. The permissible axial force, frequently stated in catalogues, is the force that is permitted to act on the front of the gearhead shaft / motor shaft from outside.

see driving area

A type of gearhead the drive shaft of which is at a given angle (normally 90°) to the output shaft. Typical angle gearheads are worm gears, bevel gearheads and crown gearheads.

An AC motor is an alternating current motor. A distinction is made between motors for single-phase current (230V/50Hz) operation and motors for three-phase current (400V/50Hz) operation. Three-phase current or rotary current, also known as power current or high-voltage current, is a system that links three alternating currents with each other. 400 Volts is the standard voltage in Germany, Austria and Switzerland. A distinction is made between shaded pole motors, capacitor motors and rotary current motors.

A ball bearing is an antifriction bearing. The best known form of ball bearing is a grooved ball bearing. It is designed to absorb mostly radial forces. As the balls are in close contact to the comparatively deep grooves, this type of bearing can absorb even slight axial forces.

A toothed wheel bonded to the motor shaft that passes on the motor torque to the first gear.

Crown wheels (also known as crown gears) are gear wheels with toothing on the flat side. These can be combined with conventional spur gears and are thus able to transmit rotation at a shaft angle of 90°.

ZEITLAUF^® spur gearheads from the Compactline range are available in models 90, 91 and 92. When dimensioning wheel widths, as regards noise generation optimisation, particular attention was given to the first stage to achieve wheels as wide as possible and thus excellent  overlap between motor shaft and intermeshing gear wheel. The combination of this increased wheel width and standard use of plastic wheels makes Compactline drives extremely smooth running and efficient.

This is a gearhead the essential component of which is a crown wheel. It can be used as an alternative to worm gears and bevel gearheads and provides the advantage of markedly better efficiency rates than worm gears and/or a simpler structure than bevel gearheads.

Commutation is the process of feeding current to individual coils in an electric motor. This is for furnishing the rotor with a rotating electromagnetic field. To do this, the correct coils must be contacted at the right point in time, depending on the current position of the rotor (magnetic north/south pole). This is achieved either mechanically as with DC motor brushes (permanent magnet motor), or electronically as with the EC motor.

This is a special version of the planet gear carrier in which the axles upon which the planet gears are located, instead of being on floating bearings, one side, are held both sides in a cage. In turn, to increase the resilience of the gearhead, the cage is also on bearings both sides. Cages are used in the “NoiselessPlus” and “Performax HRL” families of ZEITLAUF gearheads.

see direct current motor

A capacitor motor is an electric motor of the induction type. Like induction motors, it features a short circuit rotor (cage rotor) in which torque is produced by the stator, which creates an elliptical revolving field. Unlike induction motors that are fed with rotary current, the capacitor motor runs on single-phase alternating current. For details, please see induction motor.

Circumferential backlash is the amount by which the output shaft of a gearhead can be turned if, at the same time, the motor shaft is stationary.

The driving area is the milled or ground area on the output shaft. It is possible to attach a positive fitting element (e.g. belt pulley) with the help of an appropriately designed hub or a radially fitted clamping screw.

A direct current motor (DC motor), also known as a commutator motor, is an electric motor operated by direct current (normally 24 V).

Abbreviation for direct current motor. DC stands for direct current.

An electric motor is a device that converts electrical energy into mechanical energy. In electric motors, the energy that a magnetic field induces in the live conductor coil is converted into movement. This means that an electric motor is the opposite of a generator. Electric motors mostly produce rotational movement, although they can also produce translational movements (linear drive).

EtaCrown^®, an angle gearhead incorporating crown wheel technology, is the system-oriented innovation in modular gearhead manufacture. EtaCrown^® stands out in the world of angle gearheads by virtue of its excellent efficiency combined with an ability to be put to many uses. The appeal of EtaCrown^® is increased efficiency, productivity, torque and cost savings. This angle gearhead includes model ranges 75 and 52.

The encoder is a measuring device for monitoring rotor position and evaluating revs.

The efficiency rate [%] is generally the ratio of output (P_out = output) to input (P_in = input).

The rotor in a brushless direct current motor consists of a permanent magnet, the stator consists of several electromagnets. The electromagnets in the stator are powered via a bridge connection dependent on the current position of the rotor. Thus the term EC motor is also used (EC = electronic commutation).

The Focus range planetary gearheads that are designed to strict tolerances, that are extremely torsion-resistant and the product of high-quality production processes, exhibit only minimal circumferential backlash. In the first gears, plastic gearwheels with angled toothing engage with a slotted aluminium carrier. The planet gears are centred inside a planet gear carrier cage that passes on the transmitted torque to the second gear. This is equipped with a hardened, spur-toothed steel internal ring gear plus likewise hardened steel planet gears. The planet gears of the second stage are mounted by means of needle bearings on the planet gear carrier, which, in turn, is mounted on the hardened, polished, double ball bearing-mounted output shaft.

The fastening diameter is the circle around which the gearhead fixing holes are located (provided these form a circle around the output shaft).

A floating bearing is a machine element or component that slides on or in a bearing (guide slide bearing). Unlike other types of bearings (antifriction bearings), the elements of a floating bearing move past each other direct, or separated merely by a film of lubricant, and therefore normally need excellent lubrication to prevent sliding friction. This lubrication can be achieved with lubricating oils, lubricating grease as well as with soft metal bearings (copper, bronze, tin etc.) as well as with other methods of self-lubrication.

Spur gearheads from the ZEITLAUF^® Flatline range are ideal whenever the length of the place of installation is limited. Flatline gearheads include model ranges 50, 78 and 85. The first gears of all drives in this group feature plastic gearwheels with angled toothing that provide optimum silencing. The following gears are all perfectly designed in terms of low noise generation and torque transmission.

see feather key

A feather key is an extra component used with a shaft to collar connection. The connection is positive fitting and serves to transmit torques and revs (e.g. drive shaft – belt pulley).

A gear motor is a motor (normally an electric motor) combined with a gearhead. The purpose of the gearhead is to turn the output shaft, normally with less speed but with considerably more torque than the motor.

A gear wheel is a wheel with teeth and tooth spaces around it. These engage with another component (wheel or rod) that has matching teeth, and they transmit the input or output force, without any slip. The contact points should roll apart so that little friction and wear and tear occurs (fundamental law of gearing). This is why the shape of a tooth flank is either involute or cycloid. Most toothing is involute toothing. At least one tooth must be always engaged to avoid jolting when both gear wheels turn.

see output torque

A set of at least two gear wheels (spur gearhead 2 wheels – planetary gearhead at least 3 wheels) that produce a transmission ratio. Several sets of gear wheels feature in gearheads intended to achieve higher transmission ratios.

see output power

see output speed

The intermediate flange is a turned, milled or cast part that connects the motor to the gearhead.

The Zeitlauf^® Keep-Word-Warranty for gearmotors from the standard modular system provides the following:

• replacing or repairing a defective gear motor twice in one year without any investigation of fault
• a defect record stating the cause of the defect accompanies every return delivery
• if the gear motor has been overloaded it will be replaced with a more powerful one with the original gear motor entirely set off against it

Lifetime is the period for which technical plant or equipment can be used without key components having to be replaced or without them breaking down completely. ZEITLAUF^® gearheads stand out for their above average lifetime, i.e. more than 20,000 hours.

Also known as output torque or (gearhead) input torque = the torque generated by the motor.
(see torque)

Motor output refers to the output power of the motor (revs x torque). This differs from the input power (voltage x current) due to the loss of power that occurs when the electric motor converts electrical energy into mechanical energy.

The motor shaft is a component of the electric motor and it transmits the motor’s rotational movement to the gearhead.

Also known as input speed or (gearhead) input revs = the revs generated by the motor.
(see revs)

The nominal load is the load (output torque at given output speed) that the gearhead can tolerate on a sustained basis without suffering any damage.

NoiselessPlus planetary gearheads from ZEITLAUF^® are the perfect combination of output and smoothness. Hardly audible even under the most stringent operating conditions, NoiselessPlus easily copes with extreme radial loads and permits single-stage gear reductions of 4.33 to 21 and two-stage gear reductions of 26 to 231.

Needle bearings are antifriction bearings that are particularly flat in design. The rolling elements look like needles (this is why they are called needle bearings). They are thin and relatively long cylindrical rollers.

NEMA (National Electrical Manufacturers Association) is the body that publishes the national standards applicable in the USA. ZEITLAUF^® antriebstechnik has developed a perfect and, above all, standard solution for users of servo motors and stepper motors with NEMA geometry: gearheads that are already prefabricated for fitting to NEMA motors. The NEMA interface permits fast, accurately fitting and precisely centred assembly of a wide variety of gearheads and motors.

Output speed is the number of output shaft revs per minute.

The output torque is the rotary force in Nm acting on the output shaft of a gear drive, for instance. The output torque is related to the drive torque in terms of the efficiency rate and the gear ratio.

An electrical drive converts electrical energy into mechanical energy. In so doing, some energy is lost (in the form of friction, for example). The output is the output power effectively available to the user.

The output shaft transmits the torque produced by the gearhead.

Every electrical machine must be designed for a particular type of operation, dictated by the purpose of the machine. A motor, for instance, that is constantly started and stopped has to be larger than a motor that runs at a constant load. A motor that only runs for a short time, on the other hand, can be designed smaller. 

The physical magnitude of the output is defined as work per unit of time and is measured in Watts [W]. One distinction made is between electrical output and (voltage U x current I ) and mechanical output (torque M x revs n). Factoring in the basic units for torque [Nm] and revs [1/min] yields the following formula:

P [W] = M [Nm] x n [1/min] / 955

In order to obtain a standard lifetime for gearhead and motor, the required torques (M) have to be increased by the particular operating ratio (cB) concerned to make sure the max. permissible gearhead torque (M2) is not exceeded as regards the various operating loads.

The output gear is the last gear that is directly connected to the output shaft.

The planet gear carrier bears the planet wheel shafts and transmits the torque generated by the planet gears orbiting the sun gear to the output shaft.

A pole shoe is a design feature of an electric motor. The stator coil lamination stack is geometrically designed in such a manner that it fits the rounded shape of the rotor as well as possible and encloses it (see, for instance, the structure of a shaded pole motor)

The push-on pinion is a pinion (gear wheel with few teeth) that is fixed to the non-toothed motor shaft with a clamping ring and thus transmits the motor torque to the gearhead.

see crown gearhead

Also known as commutator motor – the most common type of direct current motor.
For details please see direct current (DC) motor.

Performax^®HRL (High Radial Load) planetary gearheads from ZEITLAUF^® combine high output, smoothness, reductions from up to 17:1 in a single gear, an extraordinary efficiency rate and maximum radial load capacity – Performax^®HRL is a proven performer in every category.

A planet gear is a wheel that runs between sun gear and ring gear and thus orbits the sun gear.

A pinion is a small gear wheel (relatively few teeth). This term is customarily used for the gear wheel that is fitted to the motor and drives the gearhead.

Performax^® range planetary gearheads from ZEITLAUF^® combine high output levels and smoothness. The design features of this range include angle-serrated plastic gear wheels in the first gear plus spur toothing inside a cast zinc carrier with case-hardened steel planet gears in the second gear. Another special feature of Performax^® gearheads are planet gears with standards needle bearings for second gears. This clearly distinguishes the range from the rest of the planetary gearheads on the market.

A planetary gearhead (sometimes called a planetary drive) is a special type of toothed wheel gearhead. It is characteristically compact and has three coaxially arranged shafts. In principle it is possible to drive two shafts and use one as the output shaft (summation gear) or one shaft is driven which splits the output onto two output shafts. ZEITLAUF^® uses the planetary gearhead principle as the standard “stationary gear”. The input is provided by the centrally arranged “sun gear” that simultaneously engages with several planet gears arranged around it. The planet gears, in turn, engage in a fixed ring gear (= gearhead carrier) and thus move in orbit around the sun gear (hence the name). Gearhead output transmits via the shafts of the planet gears that are all located on a joint “planet gear carrier”, and which transmit the resulting torque to the output shaft.

The rotor is the part of the electric motor that rotates. It always consists of the motor shaft and, usually, of a laminated stack. In EC motors it also includes permanent magnets and, in DC motors includes several coils plus a commutator. In DC motors it also contains cast-in aluminium strips (squirrel cage).

Rolling bearings are bearings where two moving components, the so-called inner ring and outer ring, are separated by rolling elements. They serve to support radial and axial forces on axes and shafts and are intended to keep lost output and wear and tear caused by friction to a minimum. Rolling friction occurs mainly between the three main components, inner ring, outer ring and rolling element. As the rolling elements in the inner and outer rings roll on hardened steel surfaces with optimised lubrication, rolling friction in these bearings is relatively low.

see radial force

Revs or rotational frequency (n) or speed frequency (f) are names for the quotients resulting from the number of revs and the time (t) they require. The normal unit of measurement is rpm (revs per minute).

A ring gear is a ring with toothing on the inside. Ring gears are important elements of planetary gearheads. They directly contact the planet gears and are placed coaxially to the sun gear. But planet gears can also be combined with spur gears. This produces a spur gear that does not alter the direction of rotation of the transmitted rotational movement.

In gearheads, reduction is the slower rotation of the driven wheel compared to that of the driving wheel.

The radial force is the force acting at a right angle to the axis and is applied by transmission elements such as pinions or belt pulleys. The “max. permissible radial force”, frequently referred to in drive technology, is the force that is permitted to act on a particular part of an output shaft (specific distance from the shaft bearing point) on a sustained basis without negatively affecting the lifetime of the drive.

A stepper motor is a synchronous motor in which the rotor (rotating part of the motor with shaft) can be turned by a controlled step-action rotating electromagnetic field from the stator coils (non-rotating part of the motor) by a minimum amount (step) or its multiples. Stepper motors also exist in linear motor form.

The supporting disc is the part of the planet gear carrier that bears the axles that hold the planet gears. The output shaft, which outputs from the gearhead the torque produced by the planet gears, is mounted centrally in the supporting disc.

The standard modular system from ZEITLAUF^® antriebstechnik makes it possible for gear motor components to be combined quickly and to custom requirements. Gear motors can be ordered from the online shop with max. convenience – easy as pie:

• 3,573 drive solutions (can be custom configured)
• ready for delivery within 48 hours (up to 20 pieces)
• reliable and dependable with 100% quality control and Keep-Word-Warranty

The sun gear is the central element of a planetary gearhead, it engages with the planet gears that simultaneously rotate around it.

A stator is a fixed, non-moving part of an electric motor.

A spur gearhead is a form of gearhead characterised by parallel axes. The simplest one is the single-step spur gearhead that consists of two shafts with one gear wheel on each. However, multi-step gearheads can be produced by the addition of additional gear wheels and intermediate shafts.

Axial serrations for the shaft to collar connection provide an unlockable drive type fastening (positive locking) for high torques.

A shaded-pole motor is an electric motor of the asynchronous motor type. However, unlike asynchronous motors fed with rotary current, a shaded-pole motor runs on single-phase alternating current. For details see shaded-pole motor.

The shaft is a rotating axis on bearings that transmits torques.

Smoothness is when a machine or similar runs smoothly and problem-free with little vibration through a broad range of speeds.

This is a component of a shaded pole motor and is for producing a rotating electromagnetic field consisting of single-phase alternating current.
For details please see shaded-pole motor. 

Electric motors of various types are called servo motors. These are run in a closed loop system with a servo controller (also called amplifier). Operation can therefore be torque-controlled, speed-controlled or position-controlled. Combinations can be achieved by nesting the control loop. This makes these motors suitable for the most diverse range of applications. Normally, a servo motor will be a brushless direct current motor or a vector-controlled asynchronous motor/synchronous motor.

Toothing design includes the processes of dimensioning a gear, choosing the material from which it is made and optimising its strength and noise generation attributes. In so doing, it is possible to steer gearhead attributes in the desired direction by applying innumerable parameters (smoothness <-> torque <-> high reduction <-> small size <-> lifetime etc.).

The term toothing contact refers to the rolling contact of gear wheels given a particular distance between axles and axle angles.

Torque is the rotational force acting around the centre of an axis. Torque is measured in Nm. Output is the product of torque and revs.

The Variodrive VDC-3-49.15 motor offers technical high-performance in the smallest of spaces due to its integrated electronics and the evenness of its torque. The plus points of these Variodrive motors are the three phase external rotor motor in EC technology, the controllable and regulable motors from nominal revs to 0 at almost constant motor torque and a mechanically robust design with aluminium cap and sealed plug system (protection rating IP 54).

Worm gears are rolling contact worm gears consisting of a screw shaped so-called “worm” that turns when a gear wheel (worm wheel) engaged in it turns. Unlike with rolling contact gears, in worm gears it is the faces of the gear wheels that slide on each other. This is the main reason for the low efficiency rate (~0.45 to 0.9) of these gearheads and is also the reason most of them have to be cooled.