MicroMo spur and planetary gearheads are ideal for combination with the MicroMo DC motor program. Their compact construction and quiet operation are impressive. The zero-backlash spur gearheads are perfect for positioning applications. The hybrid gearhead combines the smooth running input stages of a spur gearhead with the power of a planetary output stage. This means that, as with each gearhead, the highest torque is achieved with the samllest volume. Options and modifications to accomodate special requirements supplement already extensive standard program.
Their robust construction make the Planetary Gearheads, in combination with MicroMo's DC motors, ideal for high torque, high performance applications. In most cases, the geartrain of the input stage is made of plastic to keep noise levels as low as possible at higher RPM's. A metal input stage is also available for extreme loads. The gearhead is mounted to the motor with a threaded flange to ensure a solid fit.
Life Performance
The operational lifetime of a reduction gearhead and motor combination is determined by:
Input speed
Output torque
Operating conditions
Environment and integration into other systems
Since a multitude of parameters prevail in any application, it is nearly impossible to state the actual lifetime that can be expected from a specific type of gearhead or motor-gearhead combination. A number of options to the standard reduction gearheads are available to increase life performance including: ball bearings, all metal gears, reinforced lubrication, and other options.
Bearings-Lubrication
Gearheads are available with a range of bearings to meet various shaft loading requirements: sintered sleeve bearings, ball bearings, and ceramic bearings. Where indicated, ball bearings are preloaded with spring washers of limited force to avoid excessive current consumption.
A higher axial shaft load or shaft press-fit force than specified in the data sheets will neutralize the preload on the ball bearings.
The satellite gears in the 38/1-2 Series Planetary Gearheads are individually supported on sintered sleeve bearings. In the 44/1 Series, the satellite gears are individually supported on needle or ball bearings.
All bearings are lubricated for life. Relubrication is not cecessary and not recommended. The use of non-approved lubricants on or around the gearheads or motors can negatively influence the function and life expectancy. The standard lubrication of the reduction gears is such to provide optimum life performance at minimum curent consumption at no-load conditions. For extended life performance, all metal gears and heavy duty lubrications are available. Specially lubricated gearheads are available for operation at extended temperature environments and under vacuum.
Spur Precision Gearheads
A wide range of high quality spur gearheads are available to complement MicroMo’s DC Motors. The all metal or plastic input-stage geartrain assures extremely quiet running. The precise construction of the spur gearhead causes very low current consumption in the motor, giving greater efficiency. The gearhead is sleeve mounted on the motor, providing a seamless in-line fit. MicroMo’s spur gearheads are ideal for high precision, low torque and noise applications.
Notes on technical data
Input speed
The recommended maximum input speed for continuous operation serves as a guideline. It is possible to operate the gearhead at higher speeds. However, to obtain optimum life performance in applications that require continuous operation and long life, the recommended speed should be considered.
Ball bearings
Ratings on load and lifetime, if not stated, are according to the information from the ball bearing manufacturers. Operating temperature range
Standard range as listed on the data sheets. Special executions for extended temperature range available on request.
Reduction ratio
The listed ratios are nominal values only, the exact ratio for each reduction gearhead can be calculated by means of the stage ratio applicable for each type.
Output torque
Continuous operation. The continuous torque provides the maximum load possible applied to the output shaft; exceeding this value will reduce the service life.
Intermittent operation. The intermittent torque value may be applied for a short period. It should be for short intervals only and not exceed 5% of the continuous duty cycle.
Direction of rotation, reversible
All gearheads are designed for clockwise and counterclockwise rotation. The indication refers to the direction of rotation as seen from the shaft end, with the motor running in a clockwise direction.
Zero-backlash Precision Gearheads
MicroMo’s zero-backlash gearheads are unique in the industry. They are dual pass spur gearheads with all metal geartrains and housings. True zero backlash performance is achieved by counter rotating the individual gear passes and preloading them on the motor pinion. Zero-backlash spur gearheads are ideal for high resolution, low torque positioning applications.
Backlash
Backlash is defined by the amount by which the width of a tooth space exceeds the width of the engaging tooth to the pitch circle. Backlash is not to be confused with elasticity or torsional stiffness of the system. The general purpose of backlash is to prevent gears from jamming when making contact on both sides of their teeth simultaneously. A small amount of backlash is desirable to provide for lubricant space and differential expansion between gear components. The backlash is measured on the output shaft, at the last geartrain stage.
Zero-backlash Gearheads
The spur gearheads, series 08/3, 12/5, 15/8, 16/8, and 22/5, with dual pass geartrains feature zero-backlash when preloaded with a MicroMo DC Motor. Preloaded gearheads result in a slight reduction in overall efficiency and load capacity.
Due to manufacturing tolerances, the preloaded gearhead could present higher and irregular internal friction torque resulting in higher and variable current consumption in the motor. However, the unusual of the MicroMo zero-backlash gearheads offers, with some compromise, an excellent and unique product for many low torque, high precision positioning applications. The preloading, especially with a small reduction ratio, is very sensitive. This operation is achieved after a defined burn-in in both directions or rotation. For this reason, gearheads with preloaded zero-backlash are only available when factory assembled to the motor.
The true zero backlash properties are maintained with new gearheads onlyl. Depending on the application, a sligh backlash could appear with usage when the gears start wearing. If the wearing is not excessive, a new preload could be considered to return the gearhead to the original zero-backlash preload.
Hybrid Precision Gearheads
The hybrid gearhead combines the smooth running input stages of a spur gearhead with the power of a planetary output stage. For added power, the output shaft and planet carrier are one single piece. The hybrid geartrain is metal but the casing is plastic thereby reducing the overall weight of the gearhead without compromising its performance. MicroMo Electronics’ hybrid gearhead is sleeve mounted on the motor for a seamless in-line fit. Options and modifications to accommodate special requirements supplement the already extensive standard program.
Assembly Instructions
It is strongly recommended to have the motors and gearheads factory assembled and tested. This will assure perfect matching and lowest current consumption. The assembly of spur and hybrid gearheads with motors requires running the motors at very low speed ato ensure the correct engagement of the gears without damage. The planetary gearheadds must not be assembled with the motor running. The motor pinion must be matched with the planetary input-stage gears to avoid misalignment before the motor is secured to the gearhead. When face mounting any gearhead, care must be taken no to exceed the specified screw depth. Driving screws beyond this point will damage the gearhead. Gearheads with metal housing can be mounted using a radial set screw.
Unspecified tolerances
Tolerances in accordance with ISO2768 medium.
Size
Tolerance
(mm)
≤ 6
± 0.1
≤ 30
± 0.2
≤ 120
± 0.3
NEW! Gearhead Ordering Guide
This 2-page guide give information on how to order gearheads including:
- Motor Diameter - Motor Length - Output Shaft - Motor Nominal Voltage - Special Configurations - Desired Gearhead Series - Desired Gear Ratio
The planetary gearbox comes with 19 standard ratios for speed reduction or torque multiplication. Maximum continuous torque is 20 Nm with intermittent torque up to 40 Nm.
[Ø38mm Precision Planetary Gearbox]
