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 engine torque, and therefore current, would have to be as much times greater as the decrease ratio which can be used. Moog offers a selection of windings in each body size that, combined with a selection of reduction ratios, offers an assortment of solution to end result requirements. Each combination of engine and gearhead offers exceptional advantages.
Precision Planetary Gearheads
32 mm Low Cost Planetary Gearhead
32 mm Accuracy Planetary Gearhead
52 mm Precision Planetary Gearhead
62 mm Precision Planetary Gearhead
81 mm Precision Planetary Gearhead
120 mm Precision Planetary Gearhead
Precision planetary gearhead.
Series P high accuracy inline planetary servo drive will gratify your most demanding automation applications. The compact style, universal housing with accuracy bearings and precision planetary gearing provides substantial torque density and will be offering high positioning effectiveness. 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
Output 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: Result with or without keyway
Because of the load sharing attributes of multiple tooth contacts,planetary gearboxes provide the highest torque and stiffness for any given envelope
Balanced planetary kinematics at high speeds combined with the associated load sharing make planetary-type gearheads well suited for servo applications
True helical technology provides elevated tooth to tooth contact ratio by 33% versus. spur gearing 12¡ helix angle produces easy and quiet operation
One piece planet carrier and end result shaft design reduces backlash
Single step machining process
Assures 100% concentricity Raises 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, large radial loads, low backlash, high input speeds and a small package size. Custom types are possible
Print Product Overview
Ever-Power PS-series gearheads supply the highest effectiveness to meet your applications torque, inertia, speed and reliability requirements. Helical gears offer smooth and quiet procedure and create higher electrical power density while keeping a small envelope size. Available in multiple frame sizes and ratios to meet a number of application requirements.
• Industrial automation
• precision planetary gearbox 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 trim into housing provides increased torsional stiffness
• Widely spaced angular speak to bearings provide result shaft with substantial radial and axial load capability
• Plasma nitride heat therapy for gears for remarkable surface dress in and shear strength
• Sealed to IP65 to protect against harsh environments
• Mounting kits 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 Acceleration (RPM)6000
DEGREE OF PROTECTION (IP)IP65
EFFICIENCY AT 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 being used for servo gearheads due to their inherent low backlash; low backlash can be the main characteristic requirement for a servo gearboxes; backlash is a measure of the accuracy of the planetary gearbox.
The fact is, fixed-axis, standard, “spur” gear arrangement systems can be designed and developed simply as easily for low backlash requirements. Furthermore, low backlash isn’t an absolute requirement for servo-based mostly automation applications. A moderately low backlash is recommended (in applications with very high start/stop, frontward/reverse cycles) in order to avoid inner shock loads in the apparatus mesh. Having said that, with today’s high-quality motor-feedback equipment and associated action controllers it is simple to compensate for backlash anytime there exists a modify in the rotation or torque-load direction.
If, for the moment, we discount backlash, after that what are the reasons for selecting a more expensive, seemingly more technical planetary systems for servo gearheads? What positive aspects do planetary gears provide?
High Torque Density: Compact Design
An important requirement of automation applications is excessive torque ability in a compact and light bundle. This great torque density requirement (a high torque/quantity or torque/weight ratio) is important for automation applications with changing high dynamic loads in order to avoid additional system inertia.
Depending upon the amount of planets, planetary devices distribute the transferred torque through multiple gear mesh points. This means a planetary gear with state three planets can transfer three times the torque of an identical sized fixed axis “regular” 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 conditions. The load distribution unto multiple equipment mesh points signifies that the load is reinforced by N contacts (where N = amount of planet gears) consequently raising the torsional stiffness of the gearbox by aspect N. This implies it considerably lowers the lost movement compared to a similar size standard gearbox; which is what’s desired.
Added inertia results within an further torque/energy requirement for both acceleration and deceleration. The smaller gears in planetary system result in lower inertia. In comparison to a same torque score standard gearbox, it is a good approximation to state that the planetary gearbox inertia is smaller by the square of the amount of planets. Once again, this advantage can be rooted in the distribution or “branching” of the load into multiple equipment mesh locations.
Modern servomotors run at large rpm’s, hence a servo gearbox should 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 regularly increasing so that you can optimize, increasingly intricate application requirements. Servomotors running at speeds in excess of 10,000 rpm are not unusual. From a score perspective, with increased velocity the power density of the engine increases proportionally without the real size maximize of the engine or electronic drive. Thus, the amp rating stays a comparable while simply the voltage must be increased. An important factor is with regards to the lubrication at large operating speeds. Fixed axis spur gears will exhibit lubrication “starvation” and quickly fail if working at high speeds since the lubricant is normally slung away. Only special means such as expensive pressurized forced lubrication systems can solve this problem. Grease lubrication can be impractical as a result of its “tunneling effect,” where the grease, as time passes, is pushed apart and cannot stream back into the mesh.
In planetary systems the lubricant cannot escape. It is continuously redistributed, “pushed and pulled” or “mixed” into the equipment contacts, ensuring secure lubrication practically in virtually any mounting location and at any quickness. Furthermore, planetary gearboxes can be grease lubricated. This feature is normally inherent in planetary gearing because of the relative movement between the various gears creating the arrangement.
The Best ‘Balanced’ Planetary Ratio from a Torque Density Viewpoint
For less complicated computation, it is preferred that the planetary gearbox ratio is an specific integer (3, 4, 6…). Since we are so used to the decimal program, we tend to use 10:1 despite the fact that it has no practical edge for the pc/servo/motion controller. Actually, as we will see, 10:1 or higher ratios are the weakest, using minimal “balanced” size gears, and hence have the cheapest torque rating.
This article addresses simple planetary gear arrangements, meaning all gears are engaging in the same plane. Almost all the epicyclical gears used in servo applications are of this simple planetary design. Physique 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. This is of the ratio of a planetary gearbox shown in the physique is obtained immediately from the initial 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 have the same size as the ring gear. Figure 2b shows the sun gear size for distinct ratios. With increased ratio the sun gear diameter (size) is decreasing.
Since gear size impacts loadability, the ratio is a strong and direct effect to the torque ranking. Figure 3a shows the gears in a 3:1, 4:1, and 10:1 simple 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 planet bearings and carrier pins, hence limiting the loadability. The 4:1 ratio is a well-well balanced ratio, with sunshine 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 small sun gear becomes a strong limiting element for the transferable torque. Simple planetary designs 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 Top quality Category 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 truth is that the backlash features practically nothing to carry out with the quality or precision of a gear. Just the regularity of the backlash can be viewed as, up to certain level, a form of measure of gear quality. From the application viewpoint the relevant problem is, “What gear real estate are influencing the accuracy of the motion?”
Positioning precision is a way of measuring how precise a desired position is reached. In a closed loop system the primary determining/influencing factors of the positioning accuracy are the accuracy and quality of the feedback unit and where the location is normally measured. If the position is measured at the ultimate outcome of the actuator, the impact of the mechanical pieces could be practically eliminated. (Direct position measurement can be used mainly in high accuracy applications such as for example machine tools). In applications with a lower positioning accuracy necessity, the feedback signal is generated by a opinions devise (resolver, encoder) in the motor. In this instance auxiliary mechanical components attached to the motor such as a gearbox, couplings, pulleys, belts, etc. will affect the positioning accuracy.
We manufacture and style high-quality gears in addition to complete speed-reduction systems. For build-to-print customized parts, assemblies, style, engineering and manufacturing services get in touch with our engineering group.
Speed reducers and gear trains can be classified according to gear type and also relative position of insight and outcome shafts. SDP/SI offers a wide variety of standard catalog items:
gearheads and speed reducers
planetary and spur gearheads
right angle and dual result right angle planetary gearheads
We realize you might not be interested in selecting a ready-to-use quickness reducer. For those of you who want to design your have special gear teach or velocity reducer we offer a broad range of accuracy gears, types, sizes and materials, available from stock.
Precision Planetary Gearheads