Precision Planetary Gearheads
The primary reason to use a gearhead is that it creates it possible to regulate a big load inertia with a comparatively small motor inertia. Without the gearhead, acceleration or velocity control of the load would require that the motor torque, and thus current, would need to be as much times higher as the reduction ratio which is used. Moog offers a selection of windings in each body size that, combined with an array of reduction ratios, provides an assortment of solution to result requirements. Each combo of electric motor and gearhead offers exclusive advantages.
Precision Planetary Gearheads
32 mm LOW PRICED Planetary Gearhead
32 mm Precision Planetary Gearhead
52 mm Accuracy 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 gratify your most demanding automation applications. The compact design, universal housing with precision bearings and accuracy planetary gearing provides large torque precision planetary gearbox density while offering high positioning performance. Series P offers exact ratios from 3:1 through 40:1 with the best efficiency and cheapest backlash in the industry.
Sizes: 60, 90, 115, 140, 180 and 220
End result Torque: Up to at least one 1,500 Nm (13,275 lb.in.)
Gear Ratios: Up to 100:1 in two stages
Input Options: Matches any servo motor
Output Options: Result with or without keyway
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 help to make 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 soft and quiet operation
One piece world carrier and productivity shaft design reduces backlash
Single step machining process
Assures 100% concentricity Increases torsional rigidity
Efficient lubrication for life
The excessive precision PS-series inline helical planetary gearheads can be found in 60-220mm frame sizes and provide high torque, large radial loads, low backlash, huge input speeds and a little package size. Custom editions are possible
Print Product Overview
Ever-Power PS-series gearheads provide the highest efficiency to meet up your applications torque, inertia, speed and accuracy requirements. Helical gears present smooth and quiet operation and create higher electrical power density while keeping a small envelope size. Available in multiple frame sizes and ratios to meet up a variety of application requirements.
• Industrial automation
• Semiconductor and electronics
• Food and beverage
• Health and beauty
• Life science
Features and Benefits
• Helical gears provide even more torque capability, lower backlash, and tranquil operation
• Ring gear slice into housing provides higher torsional stiffness
• Widely spaced angular get in touch with bearings provide result shaft with great radial and axial load capability
• Plasma nitride heat treatment for gears for wonderful surface have on and shear strength
• Sealed to IP65 to protect against harsh environments
• Mounting kits for direct and convenient assembly to hundreds of different motors
• Antenna pedestals
• Robotic actuation and propulsion
GEAR GEOMETRYHelical Planetary
FRAME 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 Acceleration (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 Choice” for Servo Gearheads
Consistent 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 the main characteristic requirement for a servo gearboxes; backlash is normally 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-primarily based automation applications. A moderately low backlash is highly recommended (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 units and associated action controllers it is easy to compensate for backlash anytime there is a modify in the rotation or torque-load direction.
If, for as soon as, we discount backlash, then what are the factors for selecting a even more expensive, seemingly more complex planetary systems for servo gearheads? What positive aspects do planetary gears present?
High Torque Density: Small Design
An important requirement of automation applications is excessive torque capacity in a compact and light package. This substantial torque density requirement (a high torque/volume or torque/weight ratio) is very important to automation applications with changing excessive dynamic loads to avoid additional system inertia.
Depending upon the amount of planets, planetary systems distribute the transferred torque through multiple gear mesh points. This means a planetary equipment with state three planets can transfer 3 x the torque of an identical sized fixed axis “common” spur gear system
Excessive rotational (torsional) stiffness, or minimized elastic windup, is very important to applications with elevated positioning accuracy and repeatability requirements; especially under fluctuating loading conditions. The strain distribution unto multiple gear mesh points means that the load is reinforced by N contacts (where N = number of planet gears) hence raising the torsional stiffness of the gearbox by element N. This implies it substantially lowers the lost movement compared to an identical size standard gearbox; and this is what’s desired.
Added inertia results within an more torque/energy requirement of both acceleration and deceleration. The smaller gears in planetary program result in lower inertia. Compared to a same torque score standard gearbox, it is a reasonable approximation to state that the planetary gearbox inertia is usually 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 gear mesh locations.
Modern day servomotors run at high rpm’s, hence a servo gearbox must be able to operate in a reliable manner at high type speeds. For servomotors, 3,000 rpm is almost the standard, and actually speeds are frequently increasing in order to optimize, increasingly complicated application requirements. Servomotors working at speeds more than 10,000 rpm are not unusual. From a ranking perspective, with increased quickness the energy density of the electric motor increases proportionally without the real size boost of the engine or electronic drive. Therefore, the amp rating stays a comparable while simply the voltage must be increased. A significant factor is with regards to the lubrication at high operating speeds. Fixed axis spur gears will exhibit lubrication “starvation” and quickly fail if jogging at high speeds because the lubricant can be slung away. Only exceptional means such as expensive pressurized forced lubrication systems can solve this problem. Grease lubrication is normally impractical due to its “tunneling effect,” where the grease, over time, is pushed apart and cannot circulation 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 any mounting placement and at any rate. Furthermore, planetary gearboxes can be grease lubricated. This feature is certainly inherent in planetary gearing because of the relative motion between the various gears making up the arrangement.
THE VERY BEST ‘Balanced’ Planetary Ratio from a Torque Density Viewpoint
For less difficult computation, it is favored that the planetary gearbox ratio is an exact integer (3, 4, 6…). Since we are very much accustomed to the decimal program, we tend to use 10:1 even though this has no practical advantage for the pc/servo/motion controller. Actually, as we will have, 10:1 or more ratios are the weakest, using the least “well-balanced” size gears, and therefore 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 found in servo applications will be of the simple planetary design. Number 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. The definition of the ratio of a planetary gearbox displayed in the determine is obtained straight from the unique kinematics of the system. It is obvious a 2:1 ratio isn’t possible in a simple planetary gear program, since to satisfy the prior equation for a ratio of 2:1, the sun gear would have to have the same size as the ring gear. Figure 2b shows the sun gear size for different ratios. With increased ratio sunlight gear diameter (size) is decreasing.
Since gear size affects loadability, the ratio is a solid and direct impact to the torque ranking. Figure 3a displays the gears in a 3:1, 4:1, and 10:1 basic system. At 3:1 ratio, sunlight gear is large and the planets are small. The planets have become “slim walled”, limiting the area for the planet bearings and carrier pins, consequently limiting the loadability. The 4:1 ratio is definitely a well-well-balanced ratio, with sunlight and planets having the same size. 5:1 and 6:1 ratios still yield rather good balanced gear sizes between planets and sunshine. With larger ratios approaching 10:1, the small sun gear becomes a strong limiting aspect for the transferable torque. Simple planetary designs with 10:1 ratios have really small sun gears, which sharply restrictions torque rating.
How Positioning Accuracy and Repeatability is Suffering from the Precision and 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 possesses practically nothing to perform with the quality or precision of a gear. Just the consistency of the backlash can be considered, up to certain level, a form of way of measuring gear quality. From the application perspective the relevant question is, “What gear homes are influencing the precision of the motion?”
Positioning reliability is a measure of how precise a desired job is reached. In a closed loop system the prime determining/influencing factors of the positioning precision are the accuracy and quality of the feedback gadget and where the situation can be measured. If the positioning is definitely measured at the ultimate productivity of the actuator, the affect of the mechanical components can be practically eliminated. (Direct position measurement is employed mainly in high precision applications such as machine tools). In applications with less positioning accuracy requirement, the feedback signal is made by a feedback devise (resolver, encoder) in the motor. In cases like this auxiliary mechanical components attached to the motor like a gearbox, couplings, pulleys, belts, etc. will effect the positioning accuracy.
We manufacture and style high-quality gears and complete speed-reduction systems. For build-to-print custom parts, assemblies, design, engineering and manufacturing services contact our engineering group.
Speed reducers and gear trains can be categorized according to equipment type and relative position of suggestions and output shafts. SDP/SI offers a wide variety of standard catalog items:
gearheads and speed reducers
planetary and spur gearheads
right angle and dual productivity right angle planetary gearheads
We realize you might not be interested in choosing the ready-to-use quickness reducer. For those of you who want to design your have special gear train or rate reducer we give you a broad range of precision gears, types, sizes and material, available from stock.
Precision Planetary Gearheads