precision planetary gearbox

Precision Planetary Gearheads
The primary reason to employ a gearhead is that it makes it possible to regulate a big 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 thus current, would have to be as many times increased as the reduction ratio which is used. Moog offers a selection of windings in each framework size that, coupled with an array of reduction ratios, offers an assortment of solution to productivity requirements. Each combination of engine and gearhead offers exceptional advantages.
Precision Planetary Gearheads
gearheads
32 mm Low Cost Planetary Gearhead
32 mm Precision Planetary Gearhead
52 mm Accuracy Planetary Gearhead
62 mm Accuracy Planetary Gearhead
81 mm Accuracy 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 design, universal housing with accuracy bearings and accuracy planetary gearing provides high torque density and will be offering high positioning effectiveness. Series P offers actual ratios from 3:1 through 40:1 with the highest efficiency and cheapest backlash in the industry.
Key Features
Sizes: 60, 90, 115, 140, 180 and 220
End 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: Output with or without keyway
Product Features
As a result of 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 associated load sharing generate 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 soft and quiet operation
One piece planet carrier and outcome shaft design reduces backlash
Single step machining process
Assures 100% concentricity Increases torsional rigidity
Efficient lubrication for life
The high precision PS-series inline helical planetary gearheads can be purchased in 60-220mm frame sizes and provide high torque, large radial loads, low backlash, high input speeds and a little package size. Custom variations are possible
Print Product Overview
Ever-Power PS-series gearheads provide the highest functionality to meet up your applications torque, inertia, speed and reliprecision planetary gearbox ability requirements. Helical gears provide smooth and quiet operation and create higher electricity density while preserving a tiny envelope size. Available in multiple body sizes and ratios to meet various 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 ability, lower backlash, and noiseless operation
• Ring gear trim into housing provides increased torsional stiffness
• Widely spaced angular get in touch with bearings provide result shaft with large radial and axial load capability
• Plasma nitride heat treatment for gears for exceptional surface wear and shear strength
• Sealed to IP65 to safeguard against harsh environments
• Mounting kits 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
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
DEGREE 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
Frequent misconceptions regarding planetary gears systems involve backlash: Planetary systems are being 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 precision of the planetary gearbox.
The fact is, fixed-axis, standard, “spur” gear arrangement systems could be designed and developed simply as easily for low backlash requirements. Furthermore, low backlash is not an absolute requirement of servo-structured automation applications. A moderately low backlash is highly recommended (in applications with very high start/stop, ahead/reverse cycles) in order to avoid internal shock loads in the apparatus mesh. That said, with today’s high-quality motor-feedback products and associated motion controllers it is easy to compensate for backlash anytime there exists a alter in the rotation or torque-load direction.
If, for as soon as, we discount backlash, after that what are the causes for selecting a even more expensive, seemingly more technical planetary systems for servo gearheads? What advantages do planetary gears present?
High Torque Density: Small Design
An important requirement of automation applications is high torque capability in a compact and light bundle. This huge torque density requirement (a high torque/quantity or torque/weight ratio) is important for automation applications with changing great dynamic loads in order to avoid additional system inertia.
Depending upon the amount of planets, planetary devices distribute the transferred torque through multiple equipment mesh points. This implies a planetary gear with say three planets can transfer three times the torque of an identical sized fixed axis “regular” spur gear system
Rotational Stiffness/Elasticity
Large rotational (torsional) stiffness, or minimized elastic windup, is very important to 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 supported by N contacts (where N = amount of planet gears) therefore increasing the torsional stiffness of the gearbox by point N. This means it significantly lowers the lost action compared to an identical size standard gearbox; and this is what’s desired.
Low Inertia
Added inertia results in an additional torque/energy requirement of both acceleration and deceleration. The smaller gears in planetary system bring about lower inertia. Compared to a same torque ranking standard gearbox, it is a reasonable approximation to state that the planetary gearbox inertia is definitely smaller by the sq . of the number of planets. Once again, this advantage is certainly rooted in the distribution or “branching” of the load into multiple equipment mesh locations.
High Speeds
Modern servomotors run at huge rpm’s, hence a servo gearbox should be able to operate in a reliable manner at high type speeds. For servomotors, 3,000 rpm is practically the standard, and actually speeds are constantly increasing so as to optimize, increasingly complicated application requirements. Servomotors running at speeds in excess of 10,000 rpm aren’t unusual. From a rating point of view, with increased velocity the power density of the electric motor increases proportionally without the real size maximize of the electric motor or electronic drive. As a result, the amp rating stays a comparable 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 jogging at high speeds for the reason that lubricant is usually slung away. Only exceptional means such as costly pressurized forced lubrication systems can solve this issue. Grease lubrication is certainly impractical because of its “tunneling effect,” where the grease, as time passes, is pushed away 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 equipment contacts, ensuring safe lubrication practically in any mounting job and at any velocity. Furthermore, planetary gearboxes could be grease lubricated. This feature is certainly inherent in planetary gearing because of the relative action between different gears creating the arrangement.
The Best ‘Balanced’ Planetary Ratio from a Torque Density Viewpoint
For simpler computation, it is recommended that the planetary gearbox ratio is an precise integer (3, 4, 6…). Since we are so used to the decimal system, we have a tendency to use 10:1 even though this has no practical benefit for the computer/servo/motion controller. Essentially, as we will have, 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. The vast majority of the epicyclical gears found in servo applications happen to be of the simple planetary design. Figure 2a illustrates a cross-section of these kinds of a planetary gear set up with its central sun gear, multiple planets (3), and the ring gear. This is of the ratio of a planetary gearbox displayed in the figure is obtained immediately from the initial kinematics of the machine. It is obvious that a 2:1 ratio isn’t 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 different ratios. With increased ratio sunlight gear size (size) is decreasing.
Since gear size affects loadability, the ratio is a strong and direct effect to the torque rating. Figure 3a displays the gears in a 3:1, 4:1, and 10:1 simple system. At 3:1 ratio, sunlight gear is large and the planets are small. The planets are becoming “skinny walled”, limiting the area for the planet bearings and carrier pins, hence limiting the loadability. The 4:1 ratio can be a well-balanced ratio, with sunlight and planets getting the same size. 5:1 and 6:1 ratios still yield reasonably good balanced equipment sizes between planets and sun. With higher ratios approaching 10:1, the tiny sun equipment becomes a solid limiting element for the transferable torque. Simple planetary patterns with 10:1 ratios have very small sunshine gears, which sharply limits torque rating.
How Positioning Precision and Repeatability is Suffering from the Precision and Top quality Category of the Servo Gearhead
As previously mentioned, it is a general misconception that the backlash of a gearbox is a measure of the quality or precision. The fact is that the backlash offers practically nothing to do with the product quality or precision of a gear. Just the consistency of the backlash can be viewed as, up to certain degree, a form of measure of gear quality. From the application point of view the relevant problem is, “What gear properties are influencing the accuracy of the motion?”
Positioning precision is a measure of how exact a desired situation is reached. In a closed loop system the prime determining/influencing factors of the positioning reliability are the accuracy and resolution of the feedback device and where the posture is definitely measured. If the positioning is measured at the final productivity of the actuator, the impact of the mechanical pieces can be practically eliminated. (Immediate position measurement is utilized mainly in very high precision applications such as for example machine tools). In applications with less positioning accuracy necessity, the feedback transmission is made by a responses devise (resolver, encoder) in the motor. In this case auxiliary mechanical components attached to the motor for instance a gearbox, couplings, pulleys, belts, etc. will affect the positioning accuracy.
We manufacture and design high-quality gears and also 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 equipment type along with relative position of suggestions 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 result right angle planetary gearheads
We realize you may not be interested in selecting a ready-to-use quickness reducer. For those of you who wish to design your individual special gear educate or acceleration reducer we provide a broad range of accuracy gears, types, sizes and material, available from stock.