Precision Planetary Gearheads
The primary reason to employ a gearhead is that it makes it possible to regulate a huge load inertia with a comparatively small motor inertia. Without the gearhead, acceleration or velocity control of the load would require that the electric motor torque, and so current, would have to be as much times greater as the reduction ratio which is used. Moog offers an array of windings in each frame size that, coupled with an array of reduction ratios, offers an range of solution to end result requirements. Each combination of electric motor and gearhead offers unique advantages.
Precision Planetary Gearheads
32 mm LOW PRICED Planetary Gearhead
32 mm Accuracy Planetary Gearhead
52 mm Precision Planetary Gearhead
62 mm Accuracy Planetary Gearhead
81 mm Precision Planetary Gearhead
120 mm Precision Planetary Gearhead
Precision planetary gearhead.
Series P high precision inline planetary servo drive will meet your most demanding automation applications. The compact design, universal housing with accuracy bearings and precision planetary gearing provides substantial torque density and will be offering high positioning effectiveness. Series P offers exact ratios from 3:1 through 40:1 with the best efficiency and lowest backlash in the market.
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: Matches any servo motor
Output Options: Output with or without keyway
Because of the load sharing features of multiple tooth contacts,planetary gearboxes supply the highest torque and stiffness for just about any given envelope
Balanced planetary kinematics at high speeds combined with the associated load sharing help to make planetary-type gearheads perfect for servo applications
Accurate helical technology provides elevated tooth to tooth contact ratio by 33% vs. spur gearing 12¡ helix angle produces easy and quiet operation
One piece world carrier and output shaft design reduces backlash
Single step machining process
Assures 100% concentricity Increases torsional rigidity
Efficient lubrication for life
The substantial precision PS-series inline helical planetary gearheads can be found in 60-220mm frame sizes and offer high torque, great radial loads, low backlash, high input speeds and a tiny package size. Custom editions 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 offer smooth and quiet procedure and create higher electricity density while maintaining a little envelope size. Obtainable in multiple body 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 ability, lower backlash, and noiseless operation
• Ring gear minimize into housing provides increased torsional stiffness
• Widely spaced angular contact bearings provide outcome shaft with large radial and axial load capability
• Plasma nitride heat treatment for gears for superb surface don and shear strength
• Sealed to IP65 to protect against harsh precision planetary gearbox environments
• Mounting products for direct and easy 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 Swiftness (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 preference” for Servo Gearheads
Recurrent misconceptions regarding planetary gears systems involve backlash: Planetary systems are being used for servo gearheads due to their inherent low backlash; low backlash is usually the main characteristic requirement of a servo gearboxes; backlash is normally a way of measuring the accuracy of the planetary gearbox.
The truth is, fixed-axis, standard, “spur” gear arrangement systems can be designed and made merely as easily for low backlash requirements. Furthermore, low backlash is not an absolute requirement for servo-structured automation applications. A moderately low backlash is a good idea (in applications with very high start/stop, ahead/reverse cycles) in order to avoid interior shock loads in the gear mesh. That said, with today’s high-quality motor-feedback gadgets and associated movement controllers it is easy to compensate for backlash anytime you will find a alter in the rotation or torque-load direction.
If, for as soon as, we discount backlash, in that case what are the factors for selecting a more expensive, seemingly more technical planetary devices for servo gearheads? What advantages do planetary gears give?
High Torque Density: Small Design
An important requirement of automation applications is excessive torque capability in a compact and light bundle. This huge torque density requirement (a high torque/quantity or torque/weight ratio) is very important to automation applications with changing large dynamic loads to avoid additional system inertia.
Depending upon the quantity of planets, planetary devices distribute the transferred torque through multiple gear mesh points. This means a planetary equipment with claim three planets can transfer three times the torque of an identical sized fixed axis “standard” spur gear system
High rotational (torsional) stiffness, or minimized elastic windup, is important for applications with elevated positioning accuracy and repeatability requirements; especially under fluctuating loading circumstances. The strain distribution unto multiple gear mesh points means that the load is supported by N contacts (where N = amount of planet gears) hence raising the torsional stiffness of the gearbox by element N. This implies it noticeably lowers the lost motion compared to a similar size standard gearbox; and this is what’s desired.
Added inertia results within an further torque/energy requirement of both acceleration and deceleration. Small gears in planetary program lead to lower inertia. In comparison to a same torque rating standard gearbox, this is a reasonable approximation to state that the planetary gearbox inertia is certainly smaller by the sq . of the amount of planets. Again, this advantage is certainly rooted in the distribution or “branching” of the load into multiple equipment mesh locations.
Modern day servomotors run at great rpm’s, hence a servo gearbox must 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 frequently increasing so as to optimize, increasingly complicated application requirements. Servomotors jogging at speeds in excess of 10,000 rpm aren’t unusual. From a score perspective, with increased swiftness the energy density of the engine 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. An important factor is in regards to the lubrication at substantial operating speeds. Set axis spur gears will exhibit lubrication “starvation” and quickly fail if working at high speeds for the reason that lubricant is definitely slung away. Only particular means such as pricey pressurized forced lubrication devices can solve this issue. Grease lubrication is usually impractical due to its “tunneling effect,” where the grease, over time, is pushed aside and cannot movement back into the mesh.
In planetary systems the lubricant cannot escape. It really is continuously redistributed, “pushed and pulled” or “mixed” into the gear contacts, ensuring safe lubrication practically in virtually any mounting posture and at any quickness. Furthermore, planetary gearboxes can be grease lubricated. This characteristic is certainly inherent in planetary gearing because of the relative motion between the different gears creating the arrangement.
The Best ‘Balanced’ Planetary Ratio from a Torque Density Viewpoint
For much easier computation, it is favored that the planetary gearbox ratio can be an actual integer (3, 4, 6…). Since we are so used to the decimal program, we tend to use 10:1 even though this has no practical gain for the computer/servo/motion controller. Essentially, as we will have, 10:1 or higher ratios will be 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 participating in the same plane. Almost all the epicyclical gears used in servo applications happen to be of this simple planetary design. Figure 2a illustrates a cross-section of this kind of a planetary gear arrangement using its central sun gear, multiple planets (3), and the ring gear. This is of the ratio of a planetary gearbox demonstrated in the physique is obtained straight from the initial kinematics of the system. It is obvious a 2:1 ratio is not possible in a straightforward planetary gear system, since to satisfy the prior equation for a ratio of 2:1, sunlight gear would have to have the same size as the ring equipment. Figure 2b shows sunlight gear size for several ratios. With increased ratio the sun gear diameter (size) is decreasing.
Since gear size impacts loadability, the ratio is a strong and direct affect to the torque rating. Figure 3a shows the gears in a 3:1, 4:1, and 10:1 straightforward system. At 3:1 ratio, the sun gear is large and the planets are small. The planets are becoming “slim walled”, limiting the space for the earth bearings and carrier pins, hence limiting the loadability. The 4:1 ratio is normally a well-well balanced ratio, with sun and planets having the same size. 5:1 and 6:1 ratios still yield quite good balanced gear sizes between planets and sunlight. With larger ratios approaching 10:1, the tiny sun gear becomes a strong limiting point for the transferable torque. Simple planetary patterns with 10:1 ratios have very small sunlight gears, which sharply restrictions torque rating.
How Positioning Precision and Repeatability is Suffering from the Precision and Quality Category 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 offers practically nothing to carry out 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 way of measuring gear quality. From the application perspective the relevant concern is, “What gear real estate are influencing the accuracy of the motion?”
Positioning precision is a measure of how actual a desired job is reached. In a shut loop system the primary determining/influencing elements of the positioning accuracy will be the accuracy and quality of the feedback system and where the location is definitely measured. If the positioning is usually measured at the final end result of the actuator, the affect of the mechanical parts can be practically eliminated. (Immediate 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 responses devise (resolver, encoder) in the engine. In this instance auxiliary mechanical components mounted on the motor for instance a gearbox, couplings, pulleys, belts, etc. will effect the positioning accuracy.
We manufacture and style high-quality gears and also complete speed-reduction systems. For build-to-print customized parts, assemblies, style, engineering and manufacturing solutions speak to our engineering group.
Speed reducers and gear trains can be categorized according to gear type in addition to relative position of type and end result shafts. SDP/SI offers a wide variety of standard catalog items:
gearheads and speed reducers
planetary and spur gearheads
correct angle and dual outcome right angle planetary gearheads
We realize you may well not be interested in selecting a ready-to-use swiftness reducer. For those of you who wish to design your own special gear teach or acceleration reducer we give you a broad range of precision gears, types, sizes and material, available from stock.
Precision Planetary Gearheads