Precision Planetary Gearheads
The primary reason to use a gearhead is that it makes it possible to control a big 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 so current, would need to be as much times increased as the reduction ratio which is used. Moog offers a selection of windings in each frame size that, coupled with an array of reduction ratios, precision planetary gearbox provides an assortment of solution to output requirements. Each combination of engine and gearhead offers unique 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 Precision 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 precision bearings and accuracy planetary gearing provides large torque density and will be offering high positioning performance. Series P offers specific ratios from 3:1 through 40:1 with the highest efficiency and lowest 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.)
Equipment Ratios: Up to 100:1 in two stages
Input Options: Suits any servo motor
Output Options: Outcome with or without keyway
Because of the load sharing characteristics 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 produce planetary-type gearheads well suited for servo applications
True helical technology provides increased tooth to tooth contact ratio by 33% versus. spur gearing 12¡ helix angle produces soft and quiet operation
One piece planet carrier and outcome shaft design reduces backlash
Single step machining process
Assures 100% concentricity Enhances torsional rigidity
Efficient lubrication forever
The great precision PS-series inline helical planetary gearheads can be found in 60-220mm frame sizes and provide high torque, excessive radial loads, low backlash, substantial input speeds and a little package size. Custom versions are possible
Print Product Overview
Ever-Power PS-series gearheads provide the highest overall performance to meet up your applications torque, inertia, speed and accuracy requirements. Helical gears provide smooth and quiet operation and create higher electric power density while preserving a little 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 more torque ability, lower backlash, and noiseless operation
• Ring gear slice into housing provides higher torsional stiffness
• Widely spaced angular speak to bearings provide outcome shaft with large radial and axial load capability
• Plasma nitride heat therapy for gears for excellent surface wear and shear strength
• Sealed to IP65 to safeguard 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
Body 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 Acceleration (RPM)6000
AMOUNT OF PROTECTION (IP)IP65
EFFICIENCY In NOMINAL TORQUE (%)94 – 97
CUSTOM VERSIONS AVAILABLEYes
The Planetary (Epicyclical) Gear System as the “Program of Choice” 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 is definitely the main characteristic requirement of a servo gearboxes; backlash can be 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 merely as easily for low backlash requirements. Furthermore, low backlash isn’t an absolute requirement of servo-based automation applications. A moderately low backlash is recommended (in applications with very high start/stop, onward/reverse cycles) in order to avoid inner shock loads in the apparatus mesh. That said, with today’s high-resolution motor-feedback devices 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 as soon as, we discount backlash, after that what are the factors for selecting a even more expensive, seemingly more technical planetary systems for servo gearheads? What advantages do planetary gears give?
High Torque Density: Small Design
An important requirement of automation applications is substantial torque capacity in a compact and light package. This high torque density requirement (a higher torque/volume or torque/fat ratio) is very important to automation applications with changing substantial dynamic loads to avoid additional system inertia.
Depending upon the quantity of planets, planetary devices distribute the transferred torque through multiple equipment mesh points. This means a planetary gear with declare three planets can transfer three times the torque of a similar sized fixed axis “typical” spur gear system
Large 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 strain distribution unto multiple equipment mesh points ensures that the load is backed by N contacts (where N = amount of planet gears) consequently increasing the torsional stiffness of the gearbox by point N. This means it considerably lowers the lost motion compared to a similar size standard gearbox; which is what’s desired.
Added inertia results in an additional torque/energy requirement for both acceleration and deceleration. Small gears in planetary system cause lower inertia. Compared to a same torque score standard gearbox, it is a reasonable approximation to state that the planetary gearbox inertia is definitely smaller by the sq . of the amount of planets. Once again, this advantage is normally rooted in the distribution or “branching” of the strain into multiple equipment mesh locations.
Contemporary servomotors run at excessive rpm’s, hence a servo gearbox must be in a position to operate in a reliable manner at high type speeds. For servomotors, 3,000 rpm is almost the standard, and actually speeds are frequently increasing to be able to optimize, increasingly sophisticated application requirements. Servomotors operating at speeds in excess of 10,000 rpm aren’t unusual. From a score point of view, with increased quickness the energy density of the motor increases proportionally without any real size maximize of the electric motor or electronic drive. Hence, the amp rating stays a comparable while just the voltage should be increased. A significant factor is with regards to the lubrication at huge operating speeds. Set axis spur gears will exhibit lubrication “starvation” and quickly fail if working at high speeds because the lubricant is normally slung away. Only specialized means such as high-priced pressurized forced lubrication systems can solve this problem. Grease lubrication can be impractical as a result of its “tunneling effect,” in which the grease, as time passes, is pushed aside and cannot stream back to the mesh.
In planetary systems the lubricant cannot escape. It is constantly redistributed, “pushed and pulled” or “mixed” into the equipment contacts, ensuring secure lubrication practically in virtually any mounting placement and at any acceleration. Furthermore, planetary gearboxes could be grease lubricated. This feature is certainly inherent in planetary gearing due to the relative movement between the different gears making up the arrangement.
The Best ‘Balanced’ Planetary Ratio from a Torque Density Point of View
For simpler computation, it is recommended that the planetary gearbox ratio can be an actual integer (3, 4, 6…). Since we are very much accustomed to the decimal program, we have a tendency to use 10:1 even though this has no practical benefit for the computer/servo/motion controller. Truly, as we will have, 10:1 or more ratios are the weakest, using the least “balanced” size gears, and hence 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 found in servo applications happen to be of this simple planetary design. Figure 2a illustrates a cross-section of these kinds of a planetary gear arrangement using its central sun equipment, multiple planets (3), and the ring gear. The definition of the ratio of a planetary gearbox displayed in the determine is obtained immediately from the unique kinematics of the machine. It is obvious that a 2:1 ratio is not possible in a simple planetary gear system, since to satisfy the previous equation for a ratio of 2:1, sunlight gear would need to possess the same size as the ring equipment. Figure 2b shows sunlight gear size for different ratios. With increased ratio sunlight gear size (size) is decreasing.
Since gear size influences loadability, the ratio is a strong and direct influence to the torque ranking. Figure 3a displays the gears in a 3:1, 4:1, and 10:1 simple system. At 3:1 ratio, sunlight gear is significant and the planets happen to be small. The planets have become “slim walled”, limiting the area for the earth bearings and carrier pins, therefore limiting the loadability. The 4:1 ratio can be a well-balanced ratio, with sun and planets having the same size. 5:1 and 6:1 ratios still yield rather good balanced gear sizes between planets and sun. With larger ratios approaching 10:1, the small sun equipment becomes a strong limiting point for the transferable torque. Simple planetary designs with 10:1 ratios have very small sunshine gears, which sharply limitations torque rating.
How Positioning Precision and Repeatability is Suffering from 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 way of measuring the quality or precision. The truth is that the backlash has practically nothing to do with the product quality or accuracy of a gear. Simply the regularity of the backlash can be viewed as, up to certain level, a form of way of measuring gear quality. From the application viewpoint the relevant query is, “What gear real estate are influencing the precision of the motion?”
Positioning reliability is a measure of how actual a desired situation is reached. In a shut loop system the primary determining/influencing elements of the positioning accuracy are the accuracy and quality of the feedback product and where the posture is measured. If the position is definitely measured at the ultimate productivity of the actuator, the effect of the mechanical elements can be practically eliminated. (Direct position measurement is used mainly in high accuracy applications such as for example machine equipment). In applications with a lesser positioning accuracy necessity, the feedback signal is produced by a responses devise (resolver, encoder) in the engine. In this instance auxiliary mechanical components mounted on the motor like a gearbox, couplings, pulleys, belts, etc. will effect the positioning accuracy.
We manufacture and design high-quality gears together with complete speed-reduction systems. For build-to-print custom parts, assemblies, design, engineering and manufacturing products and services get in touch with our engineering group.
Speed reducers and equipment trains can be categorized according to gear type and relative position of source and outcome shafts. SDP/SI offers a multitude of standard catalog items:
gearheads and speed reducers
planetary and spur gearheads
correct angle and dual result right angle planetary gearheads
We realize you might not exactly be interested in selecting a ready-to-use velocity reducer. For anybody who wish to design your unique special gear teach or acceleration reducer we give a broad range of accuracy gears, types, sizes and materials, available from stock.
Precision Planetary Gearheads