Precision Planetary Gearheads
The primary reason to employ a gearhead is that it creates it possible to regulate a big load inertia with a comparatively small motor inertia. Without the gearhead, acceleration or velocity control of the load would require that the motor torque, and thus current, would have to be as much times increased as the lowering ratio which can be used. Moog offers a selection of windings in each body size that, combined with a selection of reduction ratios, offers an assortment of solution to end result requirements. Each combination of electric motor and gearhead offers one of a kind advantages.
Precision Planetary Gearheads
32 mm Low Cost Planetary Gearhead
32 mm Precision Planetary Gearhead
52 mm Precision Planetary Gearhead
62 mm Precision Planetary Gearhead
81 mm Precision Planetary Gearhead
120 mm Precision Planetary Gearhead
Precision planetary gearhead.
Series P high accuracy inline planetary servo drive will fulfill your most demanding automation applications. The compact design, universal housing with accuracy bearings and precision planetary gearing provides great torque density and will be offering high positioning overall performance. Series P offers actual ratios from 3:1 through 40:1 with the highest efficiency and cheapest backlash in the industry.
Sizes: 60, 90, 115, 140, 180 and 220
End result Torque: Up to 1 1,500 Nm (13,275 lb.in.)
Gear Ratios: Up to 100:1 in two stages
Input Options: Fits any servo motor
Output Options: End result with or without keyway
Because of the load sharing features of multiple tooth contacts,planetary gearboxes provide the highest torque and stiffness for just about any given envelope
Balanced planetary kinematics by high speeds combined with associated load sharing generate planetary-type gearheads ideal for servo applications
Accurate helical technology provides elevated tooth to tooth contact ratio by 33% versus. spur gearing 12¡ helix angle produces even and quiet operation
One piece planet carrier and output shaft design reduces backlash
Single step machining process
Assures 100% concentricity Improves torsional rigidity
Efficient lubrication forever
The large precision PS-series inline helical planetary gearheads can be purchased in 60-220mm frame sizes and offer high torque, huge radial loads, low backlash, great input speeds and a little package size. Custom types are possible
Print Product Overview
Ever-Power PS-series gearheads supply the highest efficiency to meet up your applications torque, inertia, speed and accuracy requirements. Helical gears provide smooth and quiet operation and create higher vitality density while maintaining a small envelope size. Available in multiple framework sizes and ratios to meet up a number of application requirements.
• Industrial automation
• Semiconductor and precision planetary gearbox electronics
• Food and beverage
• Health and beauty
• Life science
Features and Benefits
• Helical gears provide even more torque capability, lower backlash, and quiet operation
• Ring gear lower into housing provides higher torsional stiffness
• Widely spaced angular get in touch with bearings provide productivity shaft with substantial radial and axial load capability
• Plasma nitride heat treatment for gears for remarkable surface dress in and shear strength
• Sealed to IP65 to protect against harsh environments
• Mounting packages for direct and easy assembly to hundreds of different motors
• Antenna pedestals
• Robotic actuation and propulsion
GEAR GEOMETRYHelical Planetary
Framework SIZE60mm | 90mm | 115mm | 142mm | 180mm | 220mm
STANDARD BACKLASH (ARC-MIN)< 4 to < 8
LOW BACKLASH (ARC-MIN)< 3 to < 6
NOMINAL TORQUE (NM)27 – 1808
NOMINAL TORQUE (IN-LBS)240 – 16091
RADIAL LOAD (N)1650 – 38000
RADIAL LOAD (LBS)370 – 8636
RATIO3, 4, 5, 7, 10, 15, 20, 25, 30, 40, 50, 70, 100:1
MAXIMUM INPUT SPEED (RPM)6000
AMOUNT OF PROTECTION (IP)IP65
EFFICIENCY For NOMINAL TORQUE (%)94 – 97
CUSTOM VERSIONS AVAILABLEYes
The Planetary (Epicyclical) Gear System as the “System of preference” for Servo Gearheads
Regular misconceptions regarding planetary gears systems involve backlash: Planetary systems are used for servo gearheads as a result of their inherent low backlash; low backlash is usually the main characteristic requirement of a servo gearboxes; backlash is definitely a way of measuring the accuracy of the planetary gearbox.
The fact is, fixed-axis, standard, “spur” gear arrangement systems could be designed and built only as easily for low backlash requirements. Furthermore, low backlash isn’t an absolute requirement for servo-structured automation applications. A moderately low backlash is a good idea (in applications with very high start/stop, onward/reverse cycles) to avoid inner shock loads in the gear mesh. Having said that, with today’s high-image resolution motor-feedback gadgets and associated action controllers it is easy to compensate for backlash anytime there is a change in the rotation or torque-load direction.
If, for as soon as, we discount backlash, in that case what are the causes for selecting a even more expensive, seemingly more technical planetary systems for servo gearheads? What advantages do planetary gears give?
High Torque Density: Compact Design
An important requirement for automation applications is substantial torque capacity in a concise and light bundle. This great torque density requirement (a high torque/volume or torque/excess weight ratio) is important for automation applications with changing great dynamic loads to avoid additional system inertia.
Depending upon the number of planets, planetary devices distribute the transferred torque through multiple equipment mesh points. This means a planetary equipment with claim three planets can transfer 3 x the torque of a similar sized fixed axis “regular” spur gear system
Huge rotational (torsional) stiffness, or minimized elastic windup, is important for applications with elevated positioning accuracy and repeatability requirements; especially under fluctuating loading circumstances. The load distribution unto multiple equipment mesh points implies that the load is backed by N contacts (where N = number of planet gears) therefore raising the torsional stiffness of the gearbox by issue N. This means it noticeably lowers the lost motion compared to an identical size standard gearbox; and this is what is desired.
Added inertia results in an extra torque/energy requirement of both acceleration and deceleration. Small gears in planetary system result in lower inertia. Compared to a same torque score standard gearbox, this is a fair approximation to say that the planetary gearbox inertia is normally smaller by the square of the number of planets. Once again, this advantage is definitely rooted in the distribution or “branching” of the strain into multiple equipment mesh locations.
Modern day servomotors run at huge rpm’s, hence a servo gearbox should be in a position to operate in a trusted manner at high source speeds. For servomotors, 3,000 rpm is practically the standard, and actually speeds are regularly increasing in order to optimize, increasingly sophisticated application requirements. Servomotors jogging at speeds more than 10,000 rpm are not unusual. From a score perspective, with increased rate the energy density of the electric motor increases proportionally without any real size maximize of the electric motor or electronic drive. Thus, the amp rating stays a comparable while simply the voltage should be increased. A significant factor is in regards to the lubrication at substantial operating speeds. Set axis spur gears will exhibit lubrication “starvation” and quickly fail if running at high speeds as the lubricant is slung away. Only exceptional means such as high-priced pressurized forced lubrication systems can solve this issue. Grease lubrication is normally impractical as a result of its “tunneling effect,” in which the grease, over time, is pushed aside and cannot circulation back into the mesh.
In planetary systems the lubricant cannot escape. It really is constantly redistributed, “pushed and pulled” or “mixed” in to the gear contacts, ensuring safe lubrication practically in any mounting location and at any acceleration. Furthermore, planetary gearboxes can be grease lubricated. This characteristic is usually inherent in planetary gearing due to the relative motion between the various gears creating the arrangement.
THE VERY BEST ‘Balanced’ Planetary Ratio from a Torque Density Viewpoint
For simpler computation, it is preferred that the planetary gearbox ratio is an exact integer (3, 4, 6…). Since we are so used to the decimal program, we have a tendency to use 10:1 despite the fact that it has no practical advantage for the pc/servo/motion controller. Actually, as we will see, 10:1 or higher ratios are the weakest, using minimal “balanced” size gears, and therefore have the lowest torque rating.
This article addresses simple planetary gear arrangements, meaning all gears are engaging in the same plane. The vast majority of the epicyclical gears used in servo applications are of this simple planetary design. Physique 2a illustrates a cross-section of these kinds of a planetary gear arrangement with its central sun gear, multiple planets (3), and the ring gear. This is of the ratio of a planetary gearbox demonstrated in the shape is obtained immediately from the unique kinematics of the machine. It is obvious that a 2:1 ratio isn’t possible in a simple planetary gear program, since to satisfy the previous equation for a ratio of 2:1, the sun gear would need to have the same diameter as the ring equipment. Figure 2b shows the sun gear size for unique ratios. With an increase of ratio sunlight gear size (size) is decreasing.
Since gear size affects loadability, the ratio is a strong and direct affect to the torque score. Figure 3a reveals the gears in a 3:1, 4:1, and 10:1 simple system. At 3:1 ratio, the sun gear is huge and the planets happen to be small. The planets are becoming “skinny walled”, limiting the space for the earth bearings and carrier pins, consequently limiting the loadability. The 4:1 ratio is definitely a well-well balanced ratio, with sunlight and planets having the same size. 5:1 and 6:1 ratios still yield reasonably good balanced gear sizes between planets and sun. With higher ratios approaching 10:1, the tiny sun gear becomes a strong limiting aspect for the transferable torque. Simple planetary styles with 10:1 ratios have really small sunlight gears, which sharply restrictions torque rating.
How Positioning Accuracy and Repeatability is Affected by the Precision and Top quality Course of the Servo Gearhead
As previously mentioned, it is a general misconception that the backlash of a gearbox is a way of measuring the quality or precision. The fact is that the backlash features practically nothing to carry out with the quality or accuracy of a gear. Only the consistency of the backlash can be viewed as, up to certain degree, a form of way of measuring gear top quality. From the application point of view the relevant problem is, “What gear properties are influencing the precision of the motion?”
Positioning reliability is a measure of how specific a desired location is reached. In a shut loop system the primary determining/influencing factors of the positioning precision are the accuracy and image resolution of the feedback product and where the position is definitely measured. If the positioning is measured at the ultimate output of the actuator, the impact of the mechanical parts could be practically eliminated. (Immediate position measurement can be used mainly in high precision applications such as machine tools). In applications with a lesser positioning accuracy need, the feedback transmission is made by a responses devise (resolver, encoder) in the engine. In this instance auxiliary mechanical components mounted on the motor such as a gearbox, couplings, pulleys, belts, etc. will impact the positioning accuracy.
We manufacture and design high-quality gears and complete speed-reduction devices. For build-to-print customized parts, assemblies, style, engineering and manufacturing solutions get in touch with our engineering group.
Speed reducers and gear trains can be classified according to equipment type and relative position of input and outcome shafts. SDP/SI offers a multitude of standard catalog items:
gearheads and speed reducers
planetary and spur gearheads
right angle and dual productivity right angle planetary gearheads
We realize you may well not be interested in choosing the ready-to-use rate reducer. For those of you who want to design your own special gear teach or quickness reducer we offer a broad range of accuracy gears, types, sizes and material, available from stock.
Precision Planetary Gearheads