precision planetary gearbox

Precision Planetary Gearheads
The primary reason to employ a gearhead is that it creates it possible to regulate a sizable 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 therefore current, would need to be as much times increased as the decrease ratio which is used. Moog offers an array of windings in each body size that, coupled with an array of reduction ratios, offers an assortment of solution to productivity requirements. Each blend of engine and gearhead offers exceptional advantages.
Precision Planetary Gearheads
gearheads
32 mm Low Cost Planetary Gearhead
32 mm Accuracy Planetary Gearhead
52 mm Precision Planetary Gearhead
62 mm Precision Planetary Gearhead
81 mm Accuracy Planetary Gearhead
120 mm Accuracy 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 huge torque density while offering high positioning performance. Series P offers actual ratios from 3:1 through 40:1 with the best efficiency and lowest backlash in the market.
Key Features
Sizes: 60, 90, 115, 140, 180 and 220
Outcome Torque: Up to 1 1,500 Nm (13,275 lb.in.)
Equipment Ratios: Up to 100:1 in two stages
Input Options: Meets any servo motor
Output Options: End result with or without keyway
Product Features
Because of the load sharing attributes of multiple tooth contacts,planetary gearboxes precision planetary gearbox provide the highest torque and stiffness for just about any given envelope
Balanced planetary kinematics at high speeds combined with the associated load sharing generate planetary-type gearheads ideal for servo applications
The case helical technology provides increased tooth to tooth contact ratio by 33% versus. spur gearing 12¡ helix angle produces simple and quiet operation
One piece world carrier and end 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 are available in 60-220mm frame sizes and provide high torque, high radial loads, low backlash, high input speeds and a small package size. Custom variations are possible
Print Product Overview
Ever-Power PS-series gearheads supply the highest functionality to meet your applications torque, inertia, speed and accuracy requirements. Helical gears offer smooth and quiet procedure and create higher electric power density while retaining a small envelope size. Obtainable in multiple body sizes and ratios to meet many different application requirements.
Markets
• Industrial automation
• Semiconductor and electronics
• Food and beverage
• Health and beauty
• Life science
• Robotics
• Military
Features and Benefits
• Helical gears provide more torque capacity, lower backlash, and noiseless operation
• Ring gear trim into housing provides increased torsional stiffness
• Widely spaced angular speak to bearings provide end result shaft with substantial radial and axial load capability
• Plasma nitride heat therapy for gears for superb surface don 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
Applications
• Packaging
• Processing
• Bottling
• Milling
• Antenna pedestals
• Conveyors
• Robotic actuation and propulsion
PERFORMANCE CHARACTERISTICS
PERFORMANCEHigh Precision
CONFIGURATIONInline
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 Velocity (RPM)6000
AMOUNT OF PROTECTION (IP)IP65
EFFICIENCY In NOMINAL TORQUE (%)94 – 97
CUSTOM VERSIONS AVAILABLEYes
The Planetary (Epicyclical) Gear System as the “System of preference” for Servo Gearheads
Recurrent 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 certainly the main characteristic requirement for a servo gearboxes; backlash is usually 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 simply as easily for low backlash requirements. Furthermore, low backlash isn’t an absolute requirement of servo-structured automation applications. A moderately low backlash is highly recommended (in applications with high start/stop, frontward/reverse cycles) to avoid interior shock loads in the apparatus mesh. Having said that, with today’s high-resolution motor-feedback devices and associated movement controllers it is simple to compensate for backlash anytime there exists a alter in the rotation or torque-load direction.
If, for the moment, we discount backlash, after that what are the causes for selecting a even more expensive, seemingly more complex planetary systems for servo gearheads? What positive aspects do planetary gears give?
High Torque Density: Small Design
An important requirement for automation applications is excessive torque capacity in a compact and light bundle. This excessive 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 quantity of planets, planetary devices distribute the transferred torque through multiple equipment mesh points. This implies a planetary equipment with claim three planets can transfer three times the torque of a similar sized fixed axis “standard” spur gear system
Rotational Stiffness/Elasticity
High 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 equipment mesh points means that the load is backed by N contacts (where N = amount of planet gears) hence increasing the torsional stiffness of the gearbox by component N. This implies it considerably lowers the lost action compared to an identical size standard gearbox; and this is what’s desired.
Low Inertia
Added inertia results within an additional torque/energy requirement of both acceleration and deceleration. The smaller gears in planetary program cause lower inertia. Compared to a same torque score standard gearbox, it is a fair approximation to say that the planetary gearbox inertia is definitely smaller by the sq . of the number of planets. Once again, this advantage can be rooted in the distribution or “branching” of the load into multiple equipment mesh locations.
High Speeds
Modern day servomotors run at large rpm’s, hence a servo gearbox should be able to operate in a trusted manner at high input speeds. For servomotors, 3,000 rpm is almost the standard, and actually speeds are regularly increasing to be able to optimize, increasingly intricate application requirements. Servomotors working at speeds more than 10,000 rpm aren’t unusual. From a rating perspective, with increased rate the power density of the engine increases proportionally without the real size increase of the motor or electronic drive. As a result, the amp rating stays about the same while just the voltage must be increased. A key point is in regards to the lubrication at great operating speeds. Fixed axis spur gears will exhibit lubrication “starvation” and quickly fail if jogging at high speeds as the lubricant is usually slung away. Only particular means such as pricey pressurized forced lubrication systems can solve this problem. Grease lubrication can be impractical due to 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 consistently redistributed, “pushed and pulled” or “mixed” into the equipment contacts, ensuring safe lubrication practically in virtually any mounting placement and at any swiftness. Furthermore, planetary gearboxes can be grease lubricated. This feature is definitely inherent in planetary gearing as a result of the relative movement between different gears creating the arrangement.
THE VERY BEST ‘Balanced’ Planetary Ratio from a Torque Density Viewpoint
For less complicated computation, it is recommended that the planetary gearbox ratio is an specific 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 gain 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 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 will be of the simple planetary design. Body 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 body is obtained straight from the unique kinematics of the machine. It is obvious a 2:1 ratio is not possible in a straightforward planetary gear program, since to satisfy the previous equation for a ratio of 2:1, sunlight gear would have to possess the same size as the ring gear. Figure 2b shows the sun gear size for numerous ratios. With increased ratio the sun gear size (size) is decreasing.
Since gear size affects loadability, the ratio is a solid and direct influence to the torque ranking. Figure 3a reveals the gears in a 3:1, 4:1, and 10:1 basic system. At 3:1 ratio, sunlight gear is huge and the planets happen to be small. The planets have become “thin walled”, limiting the area for the planet bearings and carrier pins, hence limiting the loadability. The 4:1 ratio is a well-balanced ratio, with sunlight and planets getting the same size. 5:1 and 6:1 ratios still yield fairly good balanced gear sizes between planets and sun. With bigger ratios approaching 10:1, the small sun equipment becomes a strong limiting point for the transferable torque. Simple planetary patterns with 10:1 ratios have very small sunlight gears, which sharply limits torque rating.
How Positioning Reliability 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 way of measuring the quality or precision. The truth is that the backlash has practically nothing to carry out with the quality or accuracy of a gear. Simply the regularity of the backlash can be viewed as, up to certain degree, a form of way of measuring gear quality. From the application point of view the relevant dilemma is, “What gear real estate 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 primary determining/influencing elements of the positioning precision will be the accuracy and resolution of the feedback unit and where the job is definitely measured. If the positioning can be measured at the ultimate output of the actuator, the affect of the mechanical pieces could be practically eliminated. (Direct position measurement is used mainly in very high accuracy applications such as machine tools). In applications with a lesser positioning accuracy necessity, the feedback transmission is made by a opinions 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 influence the positioning accuracy.
We manufacture and style high-quality gears together with complete speed-reduction systems. For build-to-print customized parts, assemblies, style, engineering and manufacturing providers speak to our engineering group.
Speed reducers and gear trains can be classified according to gear type and also 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 outcome right angle planetary gearheads
We realize you may well not be interested in selecting a ready-to-use speed reducer. For those of you who wish to design your very own special gear coach or acceleration reducer we provide a broad range of accuracy gears, types, sizes and material, available from stock.