precision planetary gearbox

Precision Planetary Gearheads
The primary reason to employ a gearhead is that it makes it possible to regulate a sizable 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 thus current, would need to be as many times better as the reduction ratio which is used. Moog offers a selection of windings in each framework size that, combined with an array of reduction ratios, offers an range of solution to outcome requirements. Each blend of electric motor and gearhead offers exclusive advantages.
Precision Planetary Gearheads
gearheads
32 mm Low Cost Planetary Gearhead
32 mm Accuracy 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 fulfill your most demanding automation applications. The compact style, universal housing with accuracy bearings and precision planetary gearing provides huge torque density while offering high positioning overall performance. Series P offers precise ratios from 3:1 through 40:1 with the highest efficiency and lowest backlash in the industry.
Key Features
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: Suits any servo motor
Output Options: Result with or without keyway
Product Features
Because of the load sharing characteristics of multiple tooth contacts,planetary gearboxes provide the highest torque and stiffness for any given envelope
Balanced planetary kinematics for high speeds combined with the associated load sharing generate planetary-type gearheads suitable for servo applications
Accurate helical technology provides increased tooth to tooth contact ratio by 33% versus. spur gearing 12¡ helix angle produces clean and quiet operation
One piece planet carrier and end result shaft design reduces backlash
Single step machining process
Assures 100% concentricity Enhances torsional rigidity
Efficient lubrication for life
The substantial precision PS-series inline helical planetary gearheads are available in 60-220mm frame sizes and offer high torque, great radial loads, low backlash, huge input speeds and a small package size. Custom editions are possible
Print Product Overview
Ever-Power PS-series gearheads provide the highest functionality to meet your applications torque, inertia, speed and precision requirements. Helical gears give smooth and quiet operation and create higher electric power density while keeping a little envelope size. Obtainable in multiple frame sizes and ratios to meet up a range of 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 silent operation
• Ring gear minimize into housing provides better torsional stiffness
• Widely spaced angular speak to bearings provide productivity shaft with high radial and axial load capability
• Plasma nitride heat therapy for gears for superb surface don and shear strength
• Sealed to IP65 to protect precision planetary gearbox against harsh environments
• Mounting products for direct and convenient assembly to hundreds of different motors
Applications
• Packaging
• Processing
• Bottling
• Milling
• Antenna pedestals
• Conveyors
• Robotic actuation and propulsion
PERFORMANCE CHARACTERISTICS
PERFORMANCEHigh Precision
CONFIGURATIONInline
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 Velocity (RPM)6000
AMOUNT OF PROTECTION (IP)IP65
EFFICIENCY For 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 used for servo gearheads due to their inherent low backlash; low backlash is definitely the main characteristic requirement for a servo gearboxes; backlash can be a measure of the accuracy of the planetary gearbox.
The truth is, fixed-axis, standard, “spur” gear arrangement systems could be designed and created just 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 highly recommended (in applications with high start/stop, onward/reverse cycles) in order to avoid inner shock loads in the apparatus mesh. That said, with today’s high-image resolution motor-feedback equipment and associated movement controllers it is easy to compensate for backlash anytime you will find a modify in the rotation or torque-load direction.
If, for the moment, we discount backlash, in that case what are the factors for selecting a even more expensive, seemingly more complex planetary devices for servo gearheads? What advantages do planetary gears give?
High Torque Density: Small Design
An important requirement of automation applications is huge torque capacity in a compact and light bundle. This large torque density requirement (a high torque/volume or torque/excess weight ratio) is very important to automation applications with changing huge dynamic loads in order to avoid additional system inertia.
Depending upon the number of planets, planetary systems distribute the transferred torque through multiple equipment mesh points. This implies a planetary gear with state three planets can transfer 3 x the torque of a similar sized fixed axis “common” spur gear system
Rotational Stiffness/Elasticity
Substantial rotational (torsional) stiffness, or minimized elastic windup, is important for applications with elevated positioning accuracy and repeatability requirements; specifically under fluctuating loading conditions. The load distribution unto multiple equipment mesh points means that the load is reinforced by N contacts (where N = quantity of planet gears) consequently increasing the torsional stiffness of the gearbox by component N. This implies it noticeably lowers the lost action compared to a similar size standard gearbox; which is what is desired.
Low Inertia
Added inertia results within an added torque/energy requirement for both acceleration and deceleration. Small gears in planetary program lead to lower inertia. In comparison to a same torque score standard gearbox, it is a reasonable approximation to state that the planetary gearbox inertia is smaller by the sq . of the amount of planets. Again, this advantage can be rooted in the distribution or “branching” of the load into multiple gear mesh locations.
High Speeds
Modern day servomotors run at high rpm’s, hence a servo gearbox should be in a position to operate in a reliable manner at high source speeds. For servomotors, 3,000 rpm is practically the standard, and actually speeds are continuously increasing to be able to optimize, increasingly intricate application requirements. Servomotors running at speeds more than 10,000 rpm are not unusual. From a rating perspective, with increased quickness the power density of the engine increases proportionally without any real size enhance of the electric motor or electronic drive. As a result, the amp rating stays about the same while only the voltage must be increased. A key point is with regards to the lubrication at excessive operating speeds. Fixed axis spur gears will exhibit lubrication “starvation” and quickly fail if operating at high speeds since the lubricant is usually slung away. Only particular means such as high-priced pressurized forced lubrication devices can solve this problem. Grease lubrication is certainly impractical as a result of its “tunneling effect,” where the grease, over time, is pushed away and cannot circulation back into the mesh.
In planetary systems the lubricant cannot escape. It really is consistently redistributed, “pushed and pulled” or “mixed” in to the equipment contacts, ensuring safe lubrication practically in any mounting situation and at any velocity. Furthermore, planetary gearboxes can be grease lubricated. This characteristic is definitely inherent in planetary gearing because of the relative movement between different gears creating the arrangement.
The Best ‘Balanced’ Planetary Ratio from a Torque Density Perspective
For less complicated computation, it is favored that the planetary gearbox ratio can be an precise integer (3, 4, 6…). Since we are very much accustomed to the decimal system, we have a tendency to use 10:1 even though this has no practical benefit for the pc/servo/motion controller. In fact, as we will have, 10:1 or higher ratios will be the weakest, using minimal “well balanced” size gears, and therefore have the lowest torque rating.
This article addresses simple planetary gear arrangements, meaning all gears are engaging in the same plane. Almost all the epicyclical gears found in servo applications happen to be of this simple planetary design. Determine 2a illustrates a cross-section of this sort 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 body is obtained straight from the unique kinematics of the system. 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 diverse ratios. With an increase of ratio the sun gear size (size) is decreasing.
Since gear size influences loadability, the ratio is a strong and direct impact to the torque score. 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 will be small. The planets are becoming “thin walled”, limiting the space for the earth bearings and carrier pins, consequently limiting the loadability. The 4:1 ratio is a well-well balanced ratio, with sun and planets getting the same size. 5:1 and 6:1 ratios still yield fairly good balanced gear sizes between planets and sunshine. With larger ratios approaching 10:1, the small sun gear becomes a solid limiting component for the transferable torque. Simple planetary designs with 10:1 ratios have really small sunshine gears, which sharply limits torque rating.
How Positioning Reliability and Repeatability is Affected by the Precision and Top quality School 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 offers practically nothing to carry out with the quality or accuracy of a gear. Simply the consistency of the backlash can be considered, up to certain degree, a form of way of measuring gear top quality. From the application viewpoint the relevant concern is, “What gear homes are influencing the precision of the motion?”
Positioning precision is a measure of how exact a desired situation is reached. In a closed loop system the primary determining/influencing elements of the positioning reliability will be the accuracy and resolution of the feedback unit and where the placement is normally measured. If the positioning can be measured at the ultimate productivity of the actuator, the effect of the mechanical pieces can be practically eliminated. (Immediate position measurement is employed mainly in high precision applications such as for example machine tools). In applications with a lesser positioning accuracy need, the feedback signal is made by a opinions devise (resolver, encoder) in the engine. In this case 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 together with complete speed-reduction systems. For build-to-print customized parts, assemblies, design, engineering and manufacturing providers contact our engineering group.
Speed reducers and gear trains can be categorized according to equipment type and also relative position of insight and end result shafts. SDP/SI offers a multitude of standard catalog items:
gearheads and speed reducers
planetary and spur gearheads
correct angle and dual output right angle planetary gearheads
We realize you might not be interested in choosing the ready-to-use velocity reducer. For anybody who wish to design your personal special gear coach or speed reducer we offer a broad range of accuracy gears, types, sizes and material, available from stock.