Precision Planetary Gearheads
The primary reason to use a gearhead is that it creates it possible to regulate a large 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 have to be as much times higher as the reduction ratio which can be used. Moog offers an array of windings in each body size that, combined with an array of reduction ratios, provides an range of solution to result requirements. Each combo of engine and gearhead offers completely unique 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 Precision 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 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.)
Equipment Ratios: Up to 100:1 in two stages
Input Options: Matches any servo motor
Output Options: Productivity with or without keyway
As a result of load sharing features of multiple tooth contacts,planetary gearboxes provide the highest torque and stiffness for any given precision planetary gearbox envelope
Balanced planetary kinematics by high speeds combined with associated load sharing make planetary-type gearheads ideal for servo applications
Authentic helical technology provides increased tooth to tooth contact ratio by 33% versus. spur gearing 12¡ helix angle produces soft and quiet operation
One piece world carrier and outcome shaft design reduces backlash
Single step machining process
Assures 100% concentricity Enhances 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, huge radial loads, low backlash, great 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 reliability requirements. Helical gears give 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 capacity, lower backlash, and tranquil operation
• Ring gear slice into housing provides higher torsional stiffness
• Widely spaced angular contact bearings provide output shaft with excessive radial and axial load capability
• Plasma nitride heat therapy for gears for remarkable surface use 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 Rate (RPM)6000
AMOUNT OF PROTECTION (IP)IP65
EFFICIENCY AT 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 certainly 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 built 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, onward/reverse cycles) in order to avoid inner shock loads in the apparatus mesh. That said, with today’s high-quality motor-feedback units and associated movement controllers it is simple to compensate for backlash anytime there is a change in the rotation or torque-load direction.
If, for as soon as, we discount backlash, in that case what are the factors for selecting a even more expensive, seemingly more technical 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 higher 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 devices 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; specifically under fluctuating loading conditions. The strain distribution unto multiple gear mesh points means that the load is reinforced by N contacts (where N = amount of planet gears) hence raising the torsional stiffness of the gearbox by factor N. This implies it considerably 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. Small gears in planetary program cause lower inertia. In comparison to a same torque score standard gearbox, it is a reasonable approximation to state that the planetary gearbox inertia is normally smaller by the sq . of the number of planets. Once again, this advantage is definitely rooted in the distribution or “branching” of the load into multiple gear mesh locations.
Modern day servomotors run at great 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 pretty much the standard, and actually speeds are regularly increasing as a way 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 with no real size increase of the engine or electronic drive. Thus, the amp rating stays a comparable while just the voltage should be increased. A significant factor is with regards to the lubrication at huge operating speeds. Fixed axis spur gears will exhibit lubrication “starvation” and quickly fail if working at high speeds as the lubricant is definitely slung away. Only particular means such as high-priced pressurized forced lubrication systems can solve this problem. Grease lubrication is normally impractical because of its “tunneling effect,” where the grease, over time, is pushed apart and cannot move back to the mesh.
In planetary systems the lubricant cannot escape. It really is continually redistributed, “pushed and pulled” or “mixed” in to the equipment contacts, ensuring safe lubrication practically in virtually any mounting placement and at any velocity. Furthermore, planetary gearboxes can be grease lubricated. This feature is certainly inherent in planetary gearing as a result of the relative motion between the different gears making up the arrangement.
THE VERY BEST ‘Balanced’ Planetary Ratio from a Torque Density Perspective
For easier computation, it is favored that the planetary gearbox ratio is an exact integer (3, 4, 6…). Since we are so used to the decimal program, we tend to use 10:1 even though it has no practical gain for the pc/servo/motion controller. Actually, as we will have, 10:1 or more ratios will be the weakest, using the least “well-balanced” size gears, and therefore have the cheapest 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 are of the simple planetary design. Physique 2a illustrates a cross-section of such 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 system, since to satisfy the prior equation for a ratio of 2:1, sunlight gear would have to possess the same size as the ring equipment. Figure 2b shows the sun gear size for different ratios. With an increase of ratio sunlight gear diameter (size) is decreasing.
Since gear size affects loadability, the ratio is a solid and direct influence 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 significant and the planets are small. The planets have become “slim walled”, limiting the area for the earth bearings and carrier pins, consequently limiting the loadability. The 4:1 ratio is definitely a well-well-balanced ratio, with sun and planets having the same size. 5:1 and 6:1 ratios still yield rather good balanced equipment sizes between planets and sunlight. With higher 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 limitations torque rating.
How Positioning Reliability 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 truth is that the backlash features practically nothing to perform with the quality or precision of a gear. Just the consistency of the backlash can be considered, up to certain degree, 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 way of measuring 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 resolution of the feedback gadget and where the situation is definitely measured. If the positioning is definitely measured at the ultimate outcome of the actuator, the effect of the mechanical pieces can be practically eliminated. (Direct position measurement is employed mainly in high accuracy applications such as machine tools). In applications with less positioning accuracy need, the feedback signal is made by a responses 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 offerings contact our engineering group.
Speed reducers and gear trains can be categorized according to equipment type in addition to relative position of suggestions and productivity 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 unique special gear educate or rate reducer we give you a broad range of precision gears, types, sizes and material, available from stock.
Precision Planetary Gearheads