maxon gear

Technology – short and to the point

Gears Program  Output shaft  Mounting fl ange If mechanical power is required at a high torque – Planetary gearhead  Bearing of the output shaft and correspondingly reduced speed, a maxon – Spur gearhead  Axial security precision gear is recommended. According  to the gear ratio the output speed is reduced – Koaxdrive Intermediate plate

maxon gear while the output torque is enhanced. For a more – Spindle drives  Cogwheel precise determination of the latter, effi ciency  Planetary gearwheel must be taken into consideration.  Sun gearwheel Conversion  Planet carrier The conversion of speed and torque of the gear  Internal gear output (nL, ML) to the motor shaft (nmot, Mmot) fol- lows the following equations:

nmot = i · nL

ML M = mot i · ɳ

where: i: reduction η: Gearhead effi ciency

Service life Selection of gears Spur gearhead

The gears usually achieve 1000 to 3000 For the selection of the gearhead, the maximum The gear consists of one or more stages. One operating hours in continuous operation at the transmittable power – the product of speed and stage represents the pairing of two cogwheels. maximum permissible load and recommended torque – is decisive. It should be noted that the The fi rst cogwheel (pinion) is mounted directly input speed. Service life is signifi cantly extended transmittable power depends on the number of on the motor shaft. The bearing of the output if these limits are not pushed. gear stages. shaft is usually made of sintered material. If the speed drops below this threshold, the The load torque should be below the nominal – Favorably priced gearhead may be loaded with higher torques torque (max. continuous torque) of the gearhead – For low torques

without compromising the life span. On the other MN,G. – Output torque up to 2 Nm hand, higher speeds and thus higher reduction – Reduction ratios of 6:1 to 5752:1

ratios can be chosen if the torque limits are not MN,G ≥ ML – External - Ø12–45 mm fully exploited. – Low noise level Factors affecting life span include: For short-term loading, the short-term torque of – High efficiency – Exceeding maximum torque can lead to the gearhead must also be considered. excessive wear. Where possible, the input speed of the gear

– Local temperature peaks in the area of tooth nmax,G should not be exceeded. This limits the contact can destroy the lubricant. maximum possible reduction imax at a given – Massively exceeding the gear input speed operating speed. The following applies to the reduces the service life. selection of the reduction i – Radial and axial loads on the bearing.

nmax,G i ≤ i = max n Temperature/lubrication L If the gear is selected, the data conversed to maxon gears are lubricated for life. The lubri- the motor axis (n , M ) are used to select the cants used are especially effective in the recom- mot mot motor. The maxon modular system defi nes the mended temperature range. At higher or lower proper motor-gear combinations. operating temperatures we offer recommenda- tions for special lubricants.

36 Technology – short and to the point November 2014 edition / subject to change

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           maxon gear



 

Planetary gearhead Koaxdrive

Planetary gears are particularly suitable for the Ceramic versions Noise reduction transfer of high torques. Large gearheads are By using ceramic components in gearheads, Noise is primarily generated in the input stage of normally fi tted with ball bearings at gearhead the wear characteristics of critical components the gearhead. The following measures can help output. can be signifi cantly improved. The result when to reduce noise: – For transferring high torques up to 180 Nm compared to purely metal gearheads is: – Smaller input speeds and thus smaller relative – Reduction ratios of 4:1 to 6285:1 – Longer service life velocity of the tooth flanks – External diameter 6–81 mm – Higher continuous torques – Input stage with plastic gears – High performance in a small space – Higher intermittent torques – Use of a Koaxdrive gearhead – High reduction ratio in a small space – Higher input speeds – Concentric gear input and output The quiet “Koaxdrive” combines worm and High power gearhead planetary gearing. In the fi rst stage, a separately Plastic versions Especially high output torques in the output mounted worm drives the three offset planetary Favorably priced and yet compact drives can be stage of planetary gearheads can be achieved wheels which then mesh in the specially toothed realized with plastic gears. The mechanical load through the following measures internal geared wheel. All further stages are is slightly smaller than that of metal designs, – Use of ceramic components designed as a normal planetary gear: however, it is signifi cantly higher than that of – 4 instead of 3 planet gears in the output stage – low noise spur gears. – Additional motor-side support of the output – high reduction ratio in the first stage stage – other properties as planetary gears – Reinforcement of the output bearings Heavy duty gearhead The HD (heavy duty) gearheads are character- ized by their robust construction. The use of stainless steel and optimized welding joints en- able use under the most extreme conditions. Reduced backlash gearhead The reduction in backlash is achieved through a patented preloading of the planet gears in the output stage. Despite the wear that occurs dur- ing operation, the gearhead backlash remains constantly low, unlike for gearheads in which the backlash reduction is achieved by low-tolerance manufacturing and material pairing. Sterilizable gearhead Sterilizable gearheads are characterized by the use of stainless steel and special lubricants. The bearing of the output shaft and the connection to the motor are designed so that fl uid leaking into the gearhead is inhibited.

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