Precision Planetary Gearheads
The primary reason to employ a gearhead is that it makes it possible to regulate a large load inertia with a comparatively small motor inertia. Without the gearhead, acceleration or velocity control of the strain would require that the motor torque, and thus current, would have to be as many times higher as the lowering ratio which is used. Moog offers an array of windings in each framework size that, coupled with an array of reduction ratios, offers an assortment of solution to outcome requirements. Each blend of electric motor and gearhead offers exclusive advantages.
Precision Planetary Gearheads
32 mm Low Cost Planetary Gearhead
32 mm Accuracy Planetary Gearhead
52 mm Accuracy Planetary Gearhead
62 mm Precision Planetary Gearhead
81 mm Accuracy Planetary Gearhead
120 mm Accuracy Planetary Gearhead
Precision planetary gearhead.
Series P high accuracy inline planetary servo travel will fulfill your most demanding automation applications. The compact style, universal housing with accuracy bearings and accuracy planetary gearing provides excessive torque density while offering high positioning performance. Series P offers precise ratios from 3:1 through 40:1 with the best efficiency and lowest precision planetary gearbox backlash in the industry.
Sizes: 60, 90, 115, 140, 180 and 220
End result 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: Productivity with or without keyway
Due to the load sharing attributes of multiple tooth contacts,planetary gearboxes supply the highest torque and stiffness for any given envelope
Balanced planetary kinematics in high speeds combined with associated load sharing help to make planetary-type gearheads perfect for servo applications
Authentic helical technology provides elevated tooth to tooth contact ratio by 33% vs. spur gearing 12¡ helix angle produces soft 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 high precision PS-series inline helical planetary gearheads can be found in 60-220mm frame sizes and provide high torque, excessive radial loads, low backlash, high input speeds and a little package size. Custom variants are possible
Print Product Overview
Ever-Power PS-series gearheads provide the highest efficiency to meet your applications torque, inertia, speed and reliability requirements. Helical gears offer smooth and quiet procedure and create higher electricity density while retaining a tiny envelope size. Obtainable in multiple frame sizes and ratios to meet various application requirements.
• Industrial automation
• Semiconductor and electronics
• Food and beverage
• Health and beauty
• Life science
Features and Benefits
• Helical gears provide even more torque capacity, lower backlash, and quiet operation
• Ring gear minimize into housing provides higher torsional stiffness
• Widely spaced angular speak to bearings provide output shaft with excessive radial and axial load capability
• Plasma nitride heat therapy for gears for excellent surface put on and shear strength
• Sealed to IP65 to protect against harsh environments
• Mounting products for direct and convenient assembly to a huge selection 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 Swiftness (RPM)6000
DEGREE OF PROTECTION (IP)IP65
EFFICIENCY For NOMINAL TORQUE (%)94 – 97
CUSTOM VERSIONS AVAILABLEYes
The Planetary (Epicyclical) Gear System as the “Program of preference” for Servo Gearheads
Repeated misconceptions regarding planetary gears systems involve backlash: Planetary systems are used for servo gearheads as a result of their inherent low backlash; low backlash can be 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 can be designed and designed merely as easily for low backlash requirements. Furthermore, low backlash isn’t an absolute requirement of servo-primarily based automation applications. A moderately low backlash is highly recommended (in applications with high start/stop, frontward/reverse cycles) in order to avoid inner shock loads in the gear mesh. Having said that, with today’s high-resolution motor-feedback products and associated action controllers it is easy to compensate for backlash anytime you will find a modify 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 devices for servo gearheads? What positive aspects do planetary gears provide?
High Torque Density: Small Design
An important requirement for automation applications is large torque capability in a compact and light bundle. This great torque density requirement (a high torque/volume or torque/excess weight ratio) is very important to automation applications with changing substantial dynamic loads in order 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 state three planets can transfer three times the torque of an identical sized fixed axis “typical” spur gear system
Huge rotational (torsional) stiffness, or minimized elastic windup, is very important to applications with elevated positioning accuracy and repeatability requirements; specifically under fluctuating loading circumstances. The strain distribution unto multiple gear mesh points signifies that the load is backed by N contacts (where N = amount of planet gears) consequently raising the torsional stiffness of the gearbox by issue N. This means it noticeably lowers the lost movement compared to a similar size standard gearbox; and this is what’s desired.
Added inertia results in an additional torque/energy requirement of both acceleration and deceleration. The smaller gears in planetary system cause lower inertia. In comparison to a same torque score standard gearbox, it is a good 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 strain into multiple gear mesh locations.
Modern day servomotors run at huge rpm’s, hence a servo gearbox should be able to operate in a reliable manner at high suggestions speeds. For servomotors, 3,000 rpm is almost the standard, and in fact speeds are regularly increasing so as to optimize, increasingly intricate application requirements. Servomotors jogging at speeds in excess of 10,000 rpm are not unusual. From a ranking viewpoint, with increased quickness the energy density of the engine increases proportionally with no real size increase of the engine or electronic drive. As a result, the amp rating remains about the same while only the voltage must be increased. An important factor is in regards to the lubrication at large operating speeds. Fixed axis spur gears will exhibit lubrication “starvation” and quickly fail if jogging at high speeds because the lubricant can be slung away. Only specialized means such as high-priced pressurized forced lubrication systems can solve this problem. Grease lubrication is usually impractical because of its “tunneling effect,” where the grease, as time passes, is pushed apart and cannot movement back into the mesh.
In planetary systems the lubricant cannot escape. It is continually redistributed, “pushed and pulled” or “mixed” into the gear contacts, ensuring safe lubrication practically in virtually any mounting position and at any velocity. Furthermore, planetary gearboxes can be grease lubricated. This characteristic is usually inherent in planetary gearing as a result of the relative action between the various gears creating the arrangement.
The Best ‘Balanced’ Planetary Ratio from a Torque Density Viewpoint
For easier computation, it is desired that the planetary gearbox ratio is an precise integer (3, 4, 6…). Since we are so used to the decimal system, we tend to use 10:1 despite the fact that this has no practical advantages for the pc/servo/motion controller. Truly, as we will have, 10:1 or higher ratios are the weakest, using minimal “well 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. Almost all the epicyclical gears found in servo applications are of the simple planetary design. Shape 2a illustrates a cross-section of this sort of a planetary gear set up with its central sun equipment, multiple planets (3), and the ring gear. This is of the ratio of a planetary gearbox proven in the number is obtained directly from the unique kinematics of the system. It is obvious a 2:1 ratio is not 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 gear. Figure 2b shows sunlight gear size for distinct ratios. With increased ratio sunlight gear diameter (size) is decreasing.
Since gear size impacts loadability, the ratio is a solid and direct effect to the torque ranking. Figure 3a displays 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 “slim walled”, limiting the area for the earth bearings and carrier pins, hence limiting the loadability. The 4:1 ratio is definitely a well-well-balanced ratio, with sunlight and planets getting the same size. 5:1 and 6:1 ratios still yield reasonably good balanced equipment sizes between planets and sunlight. With bigger ratios approaching 10:1, the tiny sun equipment becomes a solid limiting point for the transferable torque. Simple planetary designs with 10:1 ratios have very small sunshine gears, which sharply restrictions torque rating.
How Positioning Reliability and Repeatability is Affected by the Precision and Top 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 product quality or precision. The truth is that the backlash has practically nothing to do with the quality or accuracy of a gear. Just the regularity of the backlash can be viewed as, up to certain level, a form of measure of gear top quality. From the application perspective the relevant dilemma is, “What gear houses are influencing the precision of the motion?”
Positioning reliability is a way of measuring how specific a desired location is reached. In a shut loop system the primary determining/influencing factors of the positioning accuracy will be the accuracy and quality of the feedback machine and where the posture can be measured. If the positioning is normally measured at the ultimate outcome of the actuator, the impact of the mechanical parts could be practically eliminated. (Direct position measurement is utilized mainly in high precision applications such as for example machine tools). In applications with less positioning accuracy need, the feedback transmission is produced by a opinions devise (resolver, encoder) in the electric motor. In cases like this auxiliary mechanical components attached to the motor for instance a gearbox, couplings, pulleys, belts, etc. will influence the positioning accuracy.
We manufacture and design high-quality gears and also complete speed-reduction systems. For build-to-print customized parts, assemblies, style, engineering and manufacturing services contact our engineering group.
Speed reducers and gear trains can be categorized according to gear type as well as relative position of insight and productivity shafts. SDP/SI offers a wide variety of standard catalog items:
gearheads and speed reducers
planetary and spur gearheads
correct angle and dual end result right angle planetary gearheads
We realize you might not be interested in selecting a ready-to-use quickness reducer. For anybody who want to design your have special gear educate or acceleration reducer we give you a broad range of precision gears, types, sizes and materials, available from stock.
Precision Planetary Gearheads