Precision Planetary Gearheads
The primary reason to use a gearhead is that it creates it possible to control a sizable load inertia with a comparatively small motor inertia. Without the gearhead, acceleration or velocity control of the strain would require that the engine torque, and therefore current, would need to be as much times higher as the decrease ratio which can be used. Moog offers an array of windings in each framework size that, combined with an array of reduction ratios, provides an range of solution to output requirements. Each mixture of 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 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 travel will satisfy your most demanding automation applications. The compact style, universal housing with accuracy bearings and precision planetary gearing provides high torque density while offering high positioning overall performance. Series P offers specific ratios from 3:1 through 40:1 with the best efficiency and lowest backlash in the industry.
Sizes: 60, 90, 115, 140, 180 and 220
Result Torque: Up to 1 1,500 Nm (13,275 lb.in.)
Equipment Ratios: Up to 100:1 in two stages
Input Options: Fits any servo motor
Output Options: End result with or without keyway
As a result of load sharing attributes of multiple tooth contacts,planetary gearboxes provide the highest torque and stiffness for just about any given envelope
Balanced planetary kinematics for high speeds combined with associated load sharing generate planetary-type gearheads well suited for servo applications
The case helical technology provides improved tooth to tooth contact ratio by 33% vs. spur gearing 12¡ helix angle produces soft and quiet operation
One piece planet carrier and result shaft design reduces backlash
Single step machining process
Assures 100% concentricity Boosts torsional rigidity
Efficient lubrication forever
The great precision PS-series inline helical planetary gearheads can be purchased in 60-220mm frame sizes and provide high torque, high radial loads, low backlash, substantial input speeds and a small package size. Custom variants are possible
Print Product Overview
Ever-Power PS-series gearheads supply the highest functionality to meet your applications torque, inertia, speed and precision requirements. Helical gears give smooth and quiet procedure and create higher power density while preserving a tiny envelope size. Obtainable in multiple frame sizes and ratios to meet up a number of application requirements.
• Industrial automation
• Semiconductor and electronics
• Food and beverage
• Health and beauty
• Life science
Features and Benefits
• Helical gears provide more torque capacity, lower backlash, and peaceful operation
• Ring gear lower into housing provides higher torsional stiffness
• Widely spaced angular get in touch with bearings provide output shaft with excessive radial and axial load capability
• Plasma nitride heat therapy for gears for good surface wear and shear strength
• Sealed to IP65 to safeguard against harsh environments
• Mounting precision planetary gearbox packages for direct and convenient assembly to hundreds 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 SPEED (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 Choice” for Servo Gearheads
Frequent 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 for a servo gearboxes; backlash is usually a way of measuring the precision of the planetary gearbox.
The fact is, fixed-axis, standard, “spur” gear arrangement systems can be designed and constructed only as easily for low backlash requirements. Furthermore, low backlash is not an absolute requirement for servo-based automation applications. A moderately low backlash is advisable (in applications with high start/stop, frontward/reverse cycles) in order to avoid inner shock loads in the apparatus mesh. Having said that, with today’s high-image resolution motor-feedback devices and associated motion controllers it is simple to compensate for backlash anytime there exists a adjust in the rotation or torque-load direction.
If, for as soon as, we discount backlash, then what are the causes for selecting a even more expensive, seemingly more complex planetary devices for servo gearheads? What advantages do planetary gears provide?
High Torque Density: Compact Design
An important requirement of automation applications is high torque ability in a concise and light package. This large torque density requirement (a higher torque/volume or torque/excess weight ratio) is important for automation applications with changing excessive dynamic loads to avoid additional system inertia.
Depending upon the amount of planets, planetary devices distribute the transferred torque through multiple gear mesh points. This implies a planetary gear with say three planets can transfer three times the torque of a similar sized fixed axis “regular” spur gear system
Substantial rotational (torsional) stiffness, or minimized elastic windup, is important for applications with elevated positioning accuracy and repeatability requirements; specifically under fluctuating loading circumstances. The load distribution unto multiple gear mesh points implies that the load is backed by N contacts (where N = number of planet gears) consequently increasing the torsional stiffness of the gearbox by component N. This means it substantially lowers the lost movement compared to an identical size standard gearbox; which is what is desired.
Added inertia results in an additional torque/energy requirement for both acceleration and deceleration. The smaller gears in planetary program result in lower inertia. Compared to a same torque ranking standard gearbox, it is a good approximation to say that the planetary gearbox inertia is smaller by the square of the amount of planets. Again, this advantage is rooted in the distribution or “branching” of the strain into multiple equipment mesh locations.
Modern servomotors run at high rpm’s, hence a servo gearbox must be able to operate in a reliable manner at high insight speeds. For servomotors, 3,000 rpm is pretty much the standard, and in fact speeds are constantly increasing so that you can optimize, increasingly sophisticated application requirements. Servomotors operating at speeds more than 10,000 rpm aren’t unusual. From a ranking viewpoint, with increased rate the energy density of the motor increases proportionally with no real size increase of the motor or electronic drive. Thus, the amp rating stays about the same while simply the voltage must be increased. A key point is with regards to the lubrication at great operating speeds. Set axis spur gears will exhibit lubrication “starvation” and quickly fail if running at high speeds since the lubricant is certainly slung away. Only distinctive means such as high-priced pressurized forced lubrication systems can solve this issue. Grease lubrication can be impractical as a result of its “tunneling effect,” in which the grease, as time passes, is pushed apart and cannot flow back to the mesh.
In planetary systems the lubricant cannot escape. It really is constantly redistributed, “pushed and pulled” or “mixed” into the gear contacts, ensuring secure lubrication practically in any mounting position and at any velocity. Furthermore, planetary gearboxes could be grease lubricated. This feature is inherent in planetary gearing due to the relative movement between the various gears making up the arrangement.
THE VERY BEST ‘Balanced’ Planetary Ratio from a Torque Density Perspective
For a lot easier 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 program, we tend to use 10:1 despite the fact that it has no practical benefits for the computer/servo/motion controller. In fact, as we will have, 10:1 or more ratios will be the weakest, using the least “well 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 will be of this simple planetary design. Physique 2a illustrates a cross-section of these kinds 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 shown in the figure is obtained directly from the unique kinematics of the machine. It is obvious 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 gear. Figure 2b shows the sun gear size for numerous ratios. With an increase of ratio sunlight gear size (size) is decreasing.
Since gear size influences 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 have become “skinny walled”, limiting the area for the planet bearings and carrier pins, therefore limiting the loadability. The 4:1 ratio is usually a well-well-balanced ratio, with sunlight and planets getting the same size. 5:1 and 6:1 ratios still yield fairly good balanced equipment sizes between planets and sunshine. With bigger ratios approaching 10:1, the small sun equipment becomes a solid limiting component for the transferable torque. Simple planetary styles with 10:1 ratios have really small sun gears, which sharply limits 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 features practically nothing to do with the product quality or precision of a gear. Simply the consistency of the backlash can be considered, up to certain degree, a form of measure of gear top quality. From the application viewpoint the relevant query is, “What gear properties are influencing the precision of the motion?”
Positioning reliability is a way of measuring how exact a desired placement is reached. In a shut loop system the prime determining/influencing factors of the positioning precision are the accuracy and image resolution of the feedback device and where the position is measured. If the position can be measured at the ultimate productivity of the actuator, the impact of the mechanical elements could be practically eliminated. (Immediate position measurement is used mainly in very high accuracy applications such as machine equipment). In applications with a lesser positioning accuracy requirement, the feedback transmission is made by a opinions devise (resolver, encoder) in the electric motor. In this case auxiliary mechanical components attached to the motor such as a gearbox, couplings, pulleys, belts, etc. will affect the positioning accuracy.
We manufacture and design high-quality gears in addition to complete speed-reduction devices. For build-to-print custom parts, assemblies, design, engineering and manufacturing companies contact our engineering group.
Speed reducers and gear trains can be classified according to equipment type together with 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
proper angle and dual result right angle planetary gearheads
We realize you may not be interested in selecting a ready-to-use speed reducer. For those of you who wish to design your very own special gear educate or quickness reducer we offer a broad range of precision gears, types, sizes and material, available from stock.
Precision Planetary Gearheads