Precision Planetary Gearheads
The primary reason to employ a gearhead is that it makes 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 electric motor torque, and thus current, would need to be as much times increased as the decrease ratio which can be used. Moog offers an array of windings in each body size that, coupled with a selection of reduction ratios, provides an assortment of solution to productivity requirements. Each mixture of motor and gearhead offers unique advantages.
Precision Planetary Gearheads
gearheads
32 mm LOW PRICED Planetary Gearhead
32 mm Precision Planetary Gearhead
52 mm Precision Planetary Gearhead
62 mm Accuracy Planetary Gearhead
81 mm Precision Planetary Gearhead
120 mm Precision Planetary Gearhead
Precision planetary gearhead.
Series P high precision inline planetary servo drive will gratify your most demanding automation applications. The compact style, universal housing with precision bearings and precision planetary gearing provides great torque density and will be offering high positioning functionality. Series P offers actual ratios from 3:1 through 40:1 with the best efficiency and cheapest backlash in the industry.
Key Features
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: Output with or without keyway
Product Features
Because of the load sharing attributes of multiple tooth contacts,planetary gearboxes supply 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 ideal for servo applications
Authentic helical technology provides improved tooth to tooth contact ratio by 33% versus. spur gearing 12¡ helix angle produces even and quiet operation
One piece world carrier and 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 can be purchased in 60-220mm frame sizes and provide high torque, excessive radial loads, low backlash, high input speeds and a small package size. Custom variations are possible
Print Product Overview
Ever-Power PS-series gearheads provide the highest overall performance to meet your applications torque, inertia, speed and reliability requirements. Helical gears provide smooth and quiet procedure and create higher vitality density while retaining a small envelope size. Available in multiple frame 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 even more torque capacity, lower backlash, and peaceful operation
• Ring gear cut into housing provides greater torsional stiffness
• Widely spaced angular get in touch with bearings provide output shaft with large radial and axial load capability
• Plasma nitride heat treatment for gears for remarkable surface wear and shear strength
• Sealed to IP65 to protect 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 precision planetary gearbox 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 Swiftness (RPM)6000
DEGREE OF PROTECTION (IP)IP65
EFFICIENCY By NOMINAL TORQUE (%)94 – 97
CUSTOM VERSIONS AVAILABLEYes
The Planetary (Epicyclical) Gear System as the “System of Choice” for Servo Gearheads
Frequent misconceptions regarding planetary gears systems involve backlash: Planetary systems are being used for servo gearheads because of their inherent low backlash; low backlash is usually the main characteristic requirement for a servo gearboxes; backlash can be a measure of the accuracy of the planetary gearbox.
The fact is, fixed-axis, standard, “spur” gear arrangement systems could be designed and designed merely as easily for low backlash requirements. Furthermore, low backlash isn’t an absolute requirement for servo-structured automation applications. A moderately low backlash is highly recommended (in applications with high start/stop, frontward/reverse cycles) to avoid internal shock loads in the apparatus mesh. Having said that, with today’s high-quality motor-feedback equipment and associated action controllers it is easy to compensate for backlash anytime you will find a alter in the rotation or torque-load direction.
If, for as soon as, we discount backlash, after that what are the factors for selecting a even more expensive, seemingly more complex planetary systems for servo gearheads? What advantages do planetary gears deliver?
High Torque Density: Compact Design
An important requirement for automation applications is excessive torque ability in a concise and light package. This huge torque density requirement (a high torque/volume or torque/fat 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 equipment mesh points. This implies a planetary gear with claim three planets can transfer three times the torque of a similar sized fixed axis “normal” spur gear system
Rotational Stiffness/Elasticity
Huge rotational (torsional) stiffness, or minimized elastic windup, is important for applications with elevated positioning accuracy and repeatability requirements; specifically under fluctuating loading conditions. The strain distribution unto multiple gear mesh points implies that the load is reinforced by N contacts (where N = quantity of planet gears) therefore raising the torsional stiffness of the gearbox by point N. This implies it noticeably lowers the lost action compared to an identical size standard gearbox; which is what’s desired.
Low Inertia
Added inertia results in an added torque/energy requirement of both acceleration and deceleration. Small gears in planetary program result in lower inertia. In comparison to a same torque ranking standard gearbox, it is a fair approximation to state that the planetary gearbox inertia is certainly smaller by the square of the number of planets. Again, this advantage is certainly rooted in the distribution or “branching” of the strain into multiple equipment mesh locations.
High Speeds
Contemporary servomotors run at great rpm’s, hence a servo gearbox must be in a position to operate in a trusted manner at high input speeds. For servomotors, 3,000 rpm is pretty much the standard, and actually speeds are frequently increasing as a way to optimize, increasingly intricate application requirements. Servomotors working at speeds in excess of 10,000 rpm aren’t unusual. From a rating point of view, with increased swiftness the energy density of the electric motor increases proportionally without the real size enhance of the electric motor or electronic drive. Thus, the amp rating remains a comparable while just the voltage must be increased. A significant factor is in regards to the lubrication at substantial operating speeds. Set axis spur gears will exhibit lubrication “starvation” and quickly fail if operating at high speeds for the reason that lubricant is definitely slung away. Only distinctive means such as high-priced pressurized forced lubrication devices can solve this issue. Grease lubrication can be impractical as a result of its “tunneling effect,” where the grease, over time, is pushed apart and cannot flow back into the mesh.
In planetary systems the lubricant cannot escape. It is constantly redistributed, “pushed and pulled” or “mixed” in to the equipment contacts, ensuring safe lubrication practically in any mounting location and at any quickness. Furthermore, planetary gearboxes could be grease lubricated. This feature is definitely inherent in planetary gearing because of the relative motion between the several gears creating the arrangement.
The Best ‘Balanced’ Planetary Ratio from a Torque Density Point of View
For a lot easier computation, it is recommended that the planetary gearbox ratio can be an exact integer (3, 4, 6…). Since we are very much accustomed to the decimal program, we have a tendency to use 10:1 even though it has no practical benefits for the pc/servo/motion controller. Essentially, as we will see, 10:1 or more ratios are the weakest, using minimal “well balanced” size gears, and hence have the lowest torque rating.
This article addresses simple planetary gear arrangements, meaning all gears are participating in the same plane. The vast majority of the epicyclical gears used in servo applications happen to be of this simple planetary design. Physique 2a illustrates a cross-section of such a planetary gear arrangement using its central sun equipment, multiple planets (3), and the ring gear. The definition of the ratio of a planetary gearbox demonstrated in the shape is obtained immediately from the initial kinematics of the machine. It is obvious 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 sunlight gear size for several ratios. With an increase of ratio sunlight gear size (size) is decreasing.
Since gear size affects loadability, the ratio is a solid and direct effect to the torque score. Figure 3a reveals the gears in a 3:1, 4:1, and 10:1 straightforward system. At 3:1 ratio, the sun gear is significant and the planets are small. The planets are becoming “skinny walled”, limiting the area for the earth bearings and carrier pins, hence limiting the loadability. The 4:1 ratio is usually a well-balanced ratio, with sun and planets having the same size. 5:1 and 6:1 ratios still yield fairly good balanced equipment sizes between planets and sun. With larger ratios approaching 10:1, the tiny sun equipment becomes a strong limiting element for the transferable torque. Simple planetary styles with 10:1 ratios have very small sunlight gears, which sharply restrictions torque rating.
How Positioning Reliability and Repeatability is Affected by the Precision and Quality Class 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 fact is that the backlash features practically nothing to do with the quality or precision of a gear. Simply the consistency of the backlash can be viewed as, up to certain level, a form of measure of gear top quality. From the application point of view the relevant question is, “What gear properties are influencing the accuracy of the motion?”
Positioning accuracy is a measure of how exact a desired situation is reached. In a closed loop system the primary determining/influencing factors of the positioning reliability will be the accuracy and quality of the feedback product and where the position is definitely measured. If the positioning can be measured at the ultimate result of the actuator, the influence of the mechanical elements could be practically eliminated. (Direct position measurement is employed mainly in high precision applications such as for example machine tools). In applications with a lesser positioning accuracy necessity, the feedback transmission is made by a feedback devise (resolver, encoder) in the motor. In this instance auxiliary mechanical components mounted on the motor such as a gearbox, couplings, pulleys, belts, etc. will influence the positioning accuracy.
We manufacture and style high-quality gears in addition to complete speed-reduction devices. For build-to-print custom parts, assemblies, style, engineering and manufacturing solutions contact our engineering group.
Speed reducers and equipment trains can be classified according to equipment type together 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
proper angle and dual end result right angle planetary gearheads
We realize you may well not be interested in selecting a ready-to-use speed reducer. For anybody who want to design your own special gear educate or speed reducer we give you a broad range of precision gears, types, sizes and material, available from stock.