Precision Planetary Gearheads
The primary reason to employ a gearhead is that it creates it possible to regulate a huge load inertia with a comparatively small motor inertia. Without the gearhead, acceleration or velocity control of the strain would require that the electric motor torque, and thus current, would need to be as many times increased as the lowering ratio which can be used. Moog offers an array of windings in each frame size that, coupled with a selection of reduction ratios, offers an assortment of solution to outcome requirements. Each combination of electric motor and gearhead offers different advantages.
Precision Planetary Gearheads
32 mm Low Cost Planetary Gearhead
32 mm Precision Planetary Gearhead
52 mm Accuracy Planetary Gearhead
62 mm Accuracy Planetary Gearhead
81 mm Accuracy Planetary Gearhead
120 mm Precision Planetary Gearhead
Precision planetary gearhead.
Series P high accuracy inline planetary servo drive will meet your most demanding automation applications. The compact style, universal housing with accuracy bearings and accuracy planetary gearing provides excessive torque density and will be offering high positioning performance. Series P offers actual ratios from 3:1 through 40:1 with the best efficiency and cheapest backlash in the industry.
Sizes: 60, 90, 115, 140, 180 and 220
Output Torque: Up to at least one 1,500 Nm (13,275 lb.in.)
Equipment Ratios: Up to 100:1 in two stages
Input Options: Suits any servo motor
Output Options: End result with or without keyway
Because of the load sharing features of multiple tooth contacts,planetary gearboxes supply the highest torque and stiffness for any given envelope
Balanced planetary kinematics in high precision planetary gearbox speeds combined with the associated load sharing produce planetary-type gearheads suitable for servo applications
Authentic helical technology provides increased tooth to tooth contact ratio by 33% versus. spur gearing 12¡ helix angle produces even and quiet operation
One piece planet carrier and outcome shaft design reduces backlash
Single step machining process
Assures 100% concentricity Improves torsional rigidity
Efficient lubrication for life
The high precision PS-series inline helical planetary gearheads are available in 60-220mm frame sizes and offer high torque, large radial loads, low backlash, large input speeds and a tiny package size. Custom variants are possible
Print Product Overview
Ever-Power PS-series gearheads supply the highest efficiency to meet up your applications torque, inertia, speed and reliability requirements. Helical gears provide smooth and quiet operation and create higher electrical power density while maintaining a little envelope size. Obtainable in multiple body sizes and ratios to meet a variety of application requirements.
• Industrial automation
• Semiconductor and electronics
• Food and beverage
• Health and beauty
• Life science
Features and Benefits
• Helical gears provide more torque ability, lower backlash, and quiet operation
• Ring gear cut into housing provides higher torsional stiffness
• Widely spaced angular get in touch with bearings provide output shaft with large radial and axial load capability
• Plasma nitride heat treatment for gears for remarkable surface put on and shear strength
• Sealed to IP65 to safeguard against harsh environments
• Mounting products for direct and easy assembly to a huge selection of different motors
• Antenna pedestals
• Robotic actuation and propulsion
GEAR GEOMETRYHelical Planetary
FRAME 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 Quickness (RPM)6000
DEGREE OF PROTECTION (IP)IP65
EFFICIENCY For NOMINAL TORQUE (%)94 – 97
CUSTOM VERSIONS AVAILABLEYes
The Planetary (Epicyclical) Gear System as the “System of Choice” for Servo Gearheads
Frequent misconceptions regarding planetary gears systems involve backlash: Planetary systems are used for servo gearheads due to their inherent low backlash; low backlash is normally the main characteristic requirement for a servo gearboxes; backlash is certainly a way of measuring the accuracy of the planetary gearbox.
The truth is, fixed-axis, standard, “spur” gear arrangement systems can be designed and developed only as easily for low backlash requirements. Furthermore, low backlash isn’t an absolute requirement of servo-based automation applications. A moderately low backlash is advisable (in applications with high start/stop, frontward/reverse cycles) to avoid interior shock loads in the apparatus mesh. Having said that, with today’s high-image resolution motor-feedback products and associated movement controllers it is simple to compensate for backlash anytime there exists a transform in the rotation or torque-load direction.
If, for the moment, we discount backlash, then what are the reasons for selecting a even more expensive, seemingly more complex planetary systems for servo gearheads? What advantages do planetary gears present?
High Torque Density: Small Design
An important requirement for automation applications is huge torque capability in a compact and light bundle. This substantial torque density requirement (a high torque/quantity 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 gear mesh points. This means a planetary equipment with declare three planets can transfer 3 x the torque of an identical sized fixed axis “typical” spur gear system
Excessive rotational (torsional) stiffness, or minimized elastic windup, is very important to 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 reinforced by N contacts (where N = quantity of planet gears) consequently raising the torsional stiffness of the gearbox by issue N. This implies it noticeably lowers the lost motion compared to a similar size standard gearbox; which is what’s desired.
Added inertia results within an additional torque/energy requirement for both acceleration and deceleration. The smaller gears in planetary program cause lower inertia. In comparison to a same torque score standard gearbox, it is a fair approximation to say that the planetary gearbox inertia can be smaller by the sq . of the amount of planets. Once again, this advantage can be rooted in the distribution or “branching” of the load into multiple gear mesh locations.
Contemporary servomotors run at huge rpm’s, hence a servo gearbox must be able to operate in a trusted manner at high suggestions speeds. For servomotors, 3,000 rpm is pretty much the standard, and in fact speeds are frequently increasing so as to optimize, increasingly complex application requirements. Servomotors running at speeds more than 10,000 rpm are no
t unusual. From a score viewpoint, with increased acceleration the energy density of the electric motor increases proportionally with no real size enhance of the engine or electronic drive. Therefore, the amp rating remains about the same while only the voltage should be increased. An important factor is with regards to the lubrication at large operating speeds. Set axis spur gears will exhibit lubrication “starvation” and quickly fail if jogging at high speeds as the lubricant can be slung away. Only particular means such as high-priced pressurized forced lubrication devices can solve this problem. Grease lubrication is normally impractical because of its “tunneling effect,” in which the grease, over time, is pushed aside and cannot stream back to the mesh.
In planetary systems the lubricant cannot escape. It is continuously redistributed, “pushed and pulled” or “mixed” into the equipment contacts, ensuring safe lubrication practically in virtually any mounting placement and at any quickness. Furthermore, planetary gearboxes can be grease lubricated. This feature can be inherent in planetary gearing due to the relative action between different gears creating the arrangement.
THE VERY BEST ‘Balanced’ Planetary Ratio from a Torque Density Viewpoint
For less complicated computation, it is desired that the planetary gearbox ratio can be an precise integer (3, 4, 6…). Since we are very much accustomed to the decimal system, we have a tendency to use 10:1 despite the fact that it has no practical advantages for the computer/servo/motion controller. Essentially, as we will see, 10:1 or higher ratios are the weakest, using minimal “balanced” size gears, and therefore have the cheapest 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 found in servo applications happen to be of the simple planetary design. Physique 2a illustrates a cross-section of this sort of a planetary gear arrangement using its central sun equipment, multiple planets (3), and the ring gear. This is of the ratio of a planetary gearbox displayed in the number is obtained immediately from the unique kinematics of the machine. It is obvious a 2:1 ratio isn’t possible in a simple planetary gear system, since to satisfy the prior equation for a ratio of 2:1, sunlight gear would need to possess the same diameter as the ring equipment. Figure 2b shows sunlight gear size for different ratios. With increased ratio the sun gear size (size) is decreasing.
Since gear size influences loadability, the ratio is a solid and direct impact to the torque ranking. Figure 3a reveals the gears in a 3:1, 4:1, and 10:1 basic system. At 3:1 ratio, sunlight gear is huge and the planets will be small. The planets are becoming “thin walled”, limiting the space for the planet bearings and carrier pins, hence limiting the loadability. The 4:1 ratio is normally a well-well-balanced ratio, with sunshine and planets getting the same size. 5:1 and 6:1 ratios still yield rather good balanced equipment sizes between planets and sun. With higher ratios approaching 10:1, the small sun gear becomes a solid limiting point for the transferable torque. Simple planetary models with 10:1 ratios have very small sun gears, which sharply limits torque rating.
How Positioning Precision and Repeatability is Affected by the Precision and Quality Course of the Servo Gearhead
As previously mentioned, this is a general misconception that the backlash of a gearbox is a measure of the quality or precision. The fact is that the backlash features practically nothing to do with the product quality or accuracy of a gear. Only the regularity of the backlash can be considered, up to certain level, a form of measure of gear top quality. From the application point of view the relevant query is, “What gear properties are influencing the precision of the motion?”
Positioning precision is a way of measuring how precise a desired posture is reached. In a shut loop system the primary determining/influencing elements of the positioning accuracy are the accuracy and image resolution of the feedback unit and where the posture is measured. If the position can be measured at the ultimate result of the actuator, the effect of the mechanical pieces could be practically eliminated. (Immediate position measurement is utilized mainly in high accuracy applications such as machine equipment). In applications with a lower positioning accuracy requirement, the feedback signal is made by a feedback devise (resolver, encoder) in the motor. In this instance auxiliary mechanical components mounted on the motor like a gearbox, couplings, pulleys, belts, etc. will impact the positioning accuracy.
We manufacture and style high-quality gears and also complete speed-reduction systems. For build-to-print customized parts, assemblies, design, engineering and manufacturing providers speak to our engineering group.
Speed reducers and gear trains can be classified according to equipment type in addition to relative position of insight and end result shafts. SDP/SI offers a wide variety of standard catalog items:
gearheads and speed reducers
planetary and spur gearheads
right angle and dual end result right angle planetary gearheads
We realize you might not exactly be interested in choosing the ready-to-use acceleration reducer. For anybody who want to design your have special gear teach or swiftness reducer we provide a broad range of accuracy gears, types, sizes and material, available from stock.
Precision Planetary Gearheads