Precision Planetary Gearheads
The primary reason to employ a precision planetary gearbox Gearhead is that it creates it possible to regulate a sizable load inertia with a comparatively small motor inertia. Without the gearhead, acceleration or velocity control of the load would require that the engine torque, and so current, would have to be as many times better as the reduction ratio which is used. Moog offers an array of windings in each framework size that, coupled with a selection of reduction ratios, offers an range of solution to end result requirements. Each blend of engine and gearhead offers completely unique advantages.
Precision Planetary Gearheads
gearheads
32 mm LOW PRICED Planetary Gearhead
32 mm Precision Planetary Gearhead
52 mm Accuracy Planetary Gearhead
62 mm Precision Planetary Gearhead
81 mm Precision Planetary Gearhead
120 mm Accuracy Planetary Gearhead
Precision planetary gearhead.
Series P high precision inline planetary servo travel will gratify your most demanding automation applications. The compact design, universal housing with accuracy bearings and precision planetary gearing provides excessive torque density and will be offering high positioning performance. Series P offers exact ratios from 3:1 through 40:1 with the best efficiency and lowest 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: Meets any servo motor
Output Options: Productivity with or without keyway
Product Features
As a result of load sharing attributes of multiple tooth contacts,planetary gearboxes supply the highest torque and stiffness for just about any given envelope
Balanced planetary kinematics by high speeds combined with the associated load sharing produce planetary-type gearheads well suited for servo applications
The case helical technology provides elevated tooth to tooth contact ratio by 33% vs. spur gearing 12¡ helix angle produces even and quiet operation
One piece planet carrier and outcome shaft design reduces backlash
Single step machining process
Assures 100% concentricity Boosts torsional rigidity
Efficient lubrication for life
The huge precision PS-series inline helical planetary gearheads can be purchased in 60-220mm frame sizes and offer high torque, great radial loads, low backlash, huge input speeds and a small package size. Custom versions are possible
Print Product Overview
Ever-Power PS-series gearheads supply the highest performance to meet up your applications torque, inertia, speed and precision requirements. Helical gears provide smooth and quiet operation and create higher electric power density while maintaining a little envelope size. Obtainable in multiple framework sizes and ratios to meet up a number of 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 capability, lower backlash, and tranquil operation
• Ring gear slice into housing provides increased 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 superb surface have on and shear strength
• Sealed to IP65 to safeguard against harsh environments
• Mounting kits for direct and easy 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
Framework 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 Quickness (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
Frequent 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 can be the main characteristic requirement for a servo gearboxes; backlash is a measure of the precision of the planetary gearbox.
The fact is, fixed-axis, standard, “spur” gear arrangement systems could be designed and made just as easily for low backlash requirements. Furthermore, low backlash is not an absolute requirement of servo-based mostly automation applications. A moderately low backlash is advisable (in applications with very high start/stop, forward/reverse cycles) in order to avoid inner shock loads in the apparatus mesh. Having said that, with today’s high-quality motor-feedback devices and associated action controllers it is easy to compensate for backlash anytime there is a switch in the rotation or torque-load direction.
If, for the moment, we discount backlash, after that what are the reasons for selecting a more expensive, seemingly more technical planetary devices for servo gearheads? What advantages do planetary gears present?
High Torque Density: Small Design
An important requirement for automation applications is great torque capability in a concise and light package. This substantial torque density requirement (a high torque/volume or torque/fat ratio) is important for automation applications with changing large 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 equipment with say three planets can transfer three times the torque of an identical sized fixed axis “normal” spur gear system
Rotational Stiffness/Elasticity
Great 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 ensures that the load is reinforced by N contacts (where N = number of planet gears) consequently increasing the torsional stiffness of the gearbox by aspect N. This means it substantially lowers the lost movement compared to a similar size standard gearbox; and this is what is desired.
Low Inertia
Added inertia results within an extra torque/energy requirement of both acceleration and deceleration. The smaller gears in planetary system lead to lower inertia. Compared to a same torque score standard gearbox, it is a good approximation to state that the planetary gearbox inertia is definitely smaller by the square of the amount of planets. Again, this advantage is usually rooted in the distribution or “branching” of the strain into multiple equipment mesh locations.
High Speeds
Contemporary servomotors run at substantial 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 practically the standard, and in fact speeds are constantly increasing to be able to optimize, increasingly complex application requirements. Servomotors running at speeds more than 10,000 rpm are not unusual. From a ranking point of view, with increased acceleration the energy density of the electric motor increases proportionally with no real size maximize of the motor or electronic drive. As a result, the amp rating stays about the same while just the voltage should be increased. A significant factor is in regards to the lubrication at large operating speeds. Fixed axis spur gears will exhibit lubrication “starvation” and quickly fail if jogging at high speeds because the lubricant is definitely slung away. Only distinctive means such as expensive pressurized forced lubrication systems can solve this issue. Grease lubrication is definitely impractical as a result of its “tunneling effect,” where the grease, as time passes, is pushed apart and cannot movement back into the mesh.
In planetary systems the lubricant cannot escape. It is continuously redistributed, “pushed and pulled” or “mixed” into the gear contacts, ensuring secure lubrication practically in virtually any mounting posture and at any acceleration. Furthermore, planetary gearboxes can be grease lubricated. This feature is usually inherent in planetary gearing as a result of the relative movement between the several gears creating the arrangement.
THE VERY BEST ‘Balanced’ Planetary Ratio from a Torque Density Perspective
For a lot easier computation, it is preferred that the planetary gearbox ratio is an specific 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 advantages for the computer/servo/motion controller. Basically, as we will see, 10:1 or higher 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 this simple planetary design. Body 2a illustrates a cross-section of such a planetary gear set up using its central sun gear, multiple planets (3), and the ring gear. This is of the ratio of a planetary gearbox shown in the number is obtained straight from the unique kinematics of the system. It is obvious a 2:1 ratio is not possible in a simple planetary gear system, since to satisfy the previous equation for a ratio of 2:1, sunlight gear would have to possess the same size as the ring gear. Figure 2b shows sunlight gear size for several ratios. With an increase of ratio the sun gear size (size) is decreasing.
Since gear size impacts loadability, the ratio is a solid and direct affect to the torque rating. Figure 3a reveals the gears in a 3:1, 4:1, and 10:1 basic system. At 3:1 ratio, sunlight gear is huge and the planets are small. The planets have become “skinny walled”, limiting the space for the earth bearings and carrier pins, consequently limiting the loadability. The 4:1 ratio is usually a well-balanced ratio, with sunshine and planets having 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 small sun gear becomes a strong limiting point for the transferable torque. Simple planetary styles 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 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 perform with the product quality or precision of a gear. Only 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 properties are influencing the accuracy of the motion?”
Positioning reliability is a way of measuring how exact a desired position is reached. In a closed loop system the prime determining/influencing factors of the positioning reliability will be the accuracy and resolution of the feedback system and where the job is normally measured. If the position is measured at the final productivity of the actuator, the impact of the mechanical pieces could be practically eliminated. (Immediate position measurement is used mainly in high precision applications such as machine equipment). In applications with a lower positioning accuracy necessity, the feedback signal is generated by a responses devise (resolver, encoder) in the electric motor. In this instance 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 and also complete speed-reduction devices. For build-to-print custom parts, assemblies, design, engineering and manufacturing services contact our engineering group.
Speed reducers and equipment trains can be classified according to gear type and relative position of insight 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 productivity right angle planetary gearheads
We realize you may not be interested in selecting a ready-to-use acceleration reducer. For anybody who want to design your personal special gear coach or rate reducer we give a broad range of precision gears, types, sizes and materials, available from stock.