Precision Planetary Gearheads
The primary reason to employ a precision planetary gearbox gearhead is that it creates it possible to control a big load inertia with a comparatively small motor inertia. Without the gearhead, acceleration or velocity control of the strain would require that the engine torque, and therefore current, would have to be as much times better as the lowering ratio which can be used. Moog offers an array of windings in each body size that, coupled with a selection of reduction ratios, offers an range of solution to productivity requirements. Each combo of motor 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 Accuracy Planetary Gearhead
81 mm Accuracy Planetary Gearhead
120 mm Precision Planetary Gearhead
Precision planetary gearhead.
Series P high precision inline planetary servo drive will meet your most demanding automation applications. The compact style, universal housing with accuracy bearings and accuracy planetary gearing provides great torque density while offering high positioning efficiency. Series P offers specific ratios from 3:1 through 40:1 with the best efficiency and lowest backlash in the industry.
Sizes: 60, 90, 115, 140, 180 and 220
Outcome Torque: Up to at least one 1,500 Nm (13,275 lb.in.)
Equipment Ratios: Up to 100:1 in two stages
Input Options: Suits any servo motor
Output Options: Productivity with or without keyway
Because of the load sharing attributes of multiple tooth contacts,planetary gearboxes provide the highest torque and stiffness for just about any given envelope
Balanced planetary kinematics for high speeds combined with associated load sharing produce planetary-type gearheads well suited 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 planet carrier and end result shaft design reduces backlash
Single step machining process
Assures 100% concentricity Heightens torsional rigidity
Efficient lubrication for life
The substantial precision PS-series inline helical planetary gearheads can be purchased in 60-220mm frame sizes and offer high torque, huge radial loads, low backlash, substantial input speeds and a tiny package size. Custom variants are possible
Print Product Overview
Ever-Power PS-series gearheads supply the highest functionality to meet up your applications torque, inertia, speed and reliability requirements. Helical gears present smooth and quiet operation and create higher vitality density while maintaining a small envelope size. Available in multiple framework sizes and ratios to meet up various application requirements.
• Industrial automation
• Semiconductor and electronics
• Food and beverage
• Health and beauty
• Life science
Features and Benefits
• Helical gears provide more torque capability, lower backlash, and peaceful operation
• Ring gear trim into housing provides higher torsional stiffness
• Widely spaced angular contact bearings provide result shaft with huge radial and axial load capability
• Plasma nitride heat treatment for gears for exceptional surface have on 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
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 SPEED (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 Choice” for Servo Gearheads
Consistent misconceptions regarding planetary gears systems involve backlash: Planetary systems are being used for servo gearheads as a result of their inherent low backlash; low backlash is normally the main characteristic requirement of a servo gearboxes; backlash is certainly a measure of the accuracy of the planetary gearbox.
The fact is, fixed-axis, standard, “spur” gear arrangement systems can be designed and built only as easily for low backlash requirements. Furthermore, low backlash is not an absolute requirement for servo-based mostly automation applications. A moderately low backlash is advisable (in applications with very high start/stop, onward/reverse cycles) in order to avoid interior shock loads in the gear mesh. That said, with today’s high-quality motor-feedback equipment and associated action controllers it is simple to compensate for backlash anytime you will find a transform in the rotation or torque-load direction.
If, for as soon as, we discount backlash, then what are the reasons 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 for automation applications is excessive torque ability in a concise and light bundle. This high torque density requirement (a high torque/quantity or torque/pounds ratio) is very important to automation applications with changing great dynamic loads in order to avoid additional system inertia.
Depending upon the amount of planets, planetary systems distribute the transferred torque through multiple gear mesh points. This implies a planetary equipment with state three planets can transfer three times the torque of a similar sized fixed axis “regular” spur gear system
Large rotational (torsional) stiffness, or minimized elastic windup, is important for applications with elevated positioning accuracy and repeatability requirements; especially under fluctuating loading circumstances. The load distribution unto multiple equipment mesh points signifies that the load is reinforced by N contacts (where N = number of planet gears) hence increasing the torsional stiffness of the gearbox by factor N. This implies it noticeably lowers the lost action compared to a similar size standard gearbox; and this is what is desired.
Added inertia results within an additional torque/energy requirement for both acceleration and deceleration. The smaller gears in planetary program result in lower inertia. Compared to a same torque rating standard gearbox, this is a fair approximation to state that the planetary gearbox inertia is certainly smaller by the square of the amount of planets. Again, this advantage is normally 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 must be in a position to operate in a reliable manner at high source speeds. For servomotors, 3,000 rpm is virtually the standard, and actually speeds are regularly increasing so as to optimize, increasingly sophisticated application requirements. Servomotors running at speeds in excess of 10,000 rpm aren’t unusual. From a ranking viewpoint, with increased velocity the power density of the electric motor increases proportionally without the real size boost of the electric motor or electronic drive. As a result, the amp rating remains a comparable while just the voltage should 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 running at high speeds since the lubricant is normally slung away. Only unique means such as expensive pressurized forced lubrication systems can solve this issue. Grease lubrication can be impractical due to its “tunneling effect,” where the grease, over time, is pushed away and cannot stream back into the mesh.
In planetary systems the lubricant cannot escape. It is consistently redistributed, “pushed and pulled” or “mixed” into the gear contacts, ensuring secure lubrication practically in virtually any mounting location and at any acceleration. Furthermore, planetary gearboxes can be grease lubricated. This feature can be inherent in planetary gearing as a result of the relative motion between the several gears creating the arrangement.
THE VERY BEST ‘Balanced’ Planetary Ratio from a Torque Density Point of View
For less difficult computation, it is recommended that the planetary gearbox ratio is an specific integer (3, 4, 6…). Since we are so used to the decimal program, we have a tendency to use 10:1 despite the fact that it has no practical gain for the pc/servo/motion controller. Essentially, as we will see, 10:1 or higher ratios will be 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. Figure 2a illustrates a cross-section of this kind 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 proven in the shape is obtained straight from the initial kinematics of the machine. It is obvious a 2:1 ratio is not possible in a simple planetary gear program, since to satisfy the prior equation for a ratio of 2:1, sunlight gear would need to possess the same size as the ring gear. Figure 2b shows the sun gear size for unique ratios. With an increase of ratio sunlight gear size (size) is decreasing.
Since gear size impacts loadability, the ratio is a solid and direct influence to the torque score. Figure 3a reveals the gears in a 3:1, 4:1, and 10:1 basic system. At 3:1 ratio, the sun gear is significant and the planets are small. The planets are becoming “skinny walled”, limiting the space for the earth bearings and carrier pins, therefore limiting the loadability. The 4:1 ratio is certainly 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 sunshine. With higher ratios approaching 10:1, the tiny sun gear becomes a strong limiting element for the transferable torque. Simple planetary styles with 10:1 ratios have really small sunshine gears, which sharply limits torque rating.
How Positioning Accuracy and Repeatability is Affected by the Precision and Top quality Course of the Servo Gearhead
As previously mentioned, it is a general misconception that the backlash of a gearbox is a measure of the product quality or precision. The fact is that the backlash provides practically nothing to perform with the quality or precision of a gear. Simply the regularity of the backlash can be viewed as, up to certain degree, a form of way of measuring gear top quality. From the application viewpoint the relevant query is, “What gear homes are influencing the accuracy of the motion?”
Positioning reliability is a way of measuring how actual a desired posture is reached. In a closed loop system the primary determining/influencing factors of the positioning accuracy are the accuracy and image resolution of the feedback gadget and where the position is normally measured. If the position is usually measured at the ultimate productivity of the actuator, the effect of the mechanical parts can be practically eliminated. (Direct position measurement can be used mainly in high accuracy applications such as for example machine equipment). In applications with less positioning accuracy requirement, the feedback signal is made by a responses devise (resolver, encoder) in the motor. In this case auxiliary mechanical components mounted on the motor for instance a gearbox, couplings, pulleys, belts, etc. will impact the positioning accuracy.
We manufacture and style high-quality gears in addition to complete speed-reduction devices. For build-to-print customized parts, assemblies, design, engineering and manufacturing providers get in touch with our engineering group.
Speed reducers and equipment trains can be categorized according to equipment type along with relative position of type and output shafts. SDP/SI offers a wide variety of standard catalog items:
gearheads and speed reducers
planetary and spur gearheads
proper angle and dual outcome right angle planetary gearheads
We realize you might not be interested in selecting a ready-to-use velocity reducer. For those of you who wish to design your personal special gear train or quickness reducer we offer a broad range of accuracy gears, types, sizes and materials, available from stock.
Precision Planetary Gearheads