precision planetary gearbox

Precision Planetary Gearheads
The primary reason to employ a gearhead is that it creates it possible to regulate a sizable load inertia with a comparatively small motor inertia. precision planetary gearbox without the gearhead, acceleration or velocity control of the load would require that the engine torque, and therefore current, would have to be as much times higher as the decrease ratio which can be used. Moog offers an array of windings in each framework size that, combined with an array of reduction ratios, offers an range of solution to productivity requirements. Each blend of electric motor and gearhead offers different advantages.
Precision Planetary Gearheads
gearheads
32 mm LOW PRICED Planetary Gearhead
32 mm Accuracy Planetary Gearhead
52 mm Precision Planetary Gearhead
62 mm Accuracy Planetary Gearhead
81 mm Accuracy Planetary Gearhead
120 mm Accuracy Planetary Gearhead
Precision planetary gearhead.
Series P high precision inline planetary servo travel will satisfy your most demanding automation applications. The compact design, universal housing with accuracy bearings and precision planetary gearing provides great torque density while offering high positioning efficiency. Series P offers exact ratios from 3:1 through 40:1 with the best efficiency and cheapest backlash in the market.
Key Features
Sizes: 60, 90, 115, 140, 180 and 220
Productivity Torque: Up to at least one 1,500 Nm (13,275 lb.in.)
Gear Ratios: Up to 100:1 in two stages
Input Options: Meets any servo motor
Output Options: Result with or without keyway
Product Features
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 by high speeds combined with the associated load sharing help to make planetary-type gearheads perfect for servo applications
Authentic helical technology provides improved tooth to tooth contact ratio by 33% vs. spur gearing 12¡ helix angle produces clean and quiet operation
One piece world carrier and output shaft design reduces backlash
Single step machining process
Assures 100% concentricity Improves torsional rigidity
Efficient lubrication for life
The large precision PS-series inline helical planetary gearheads can be purchased in 60-220mm frame sizes and offer high torque, high radial loads, low backlash, huge input speeds and a small package size. Custom editions are possible
Print Product Overview
Ever-Power PS-series gearheads supply the highest functionality to meet your applications torque, inertia, speed and precision requirements. Helical gears give smooth and quiet procedure and create higher vitality density while maintaining a tiny envelope size. Available 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 capacity, lower backlash, and silent operation
• Ring gear trim into housing provides increased torsional stiffness
• Widely spaced angular contact bearings provide end result shaft with great radial and axial load capability
• Plasma nitride heat treatment for gears for remarkable surface have on and shear strength
• Sealed to IP65 to protect against harsh environments
• Mounting packages 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
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 By NOMINAL TORQUE (%)94 – 97
CUSTOM VERSIONS AVAILABLEYes
The Planetary (Epicyclical) Gear System as the “System of preference” 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 of a servo gearboxes; backlash is a way of measuring 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 isn’t an absolute requirement for servo-primarily based automation applications. A moderately low backlash is highly recommended (in applications with high start/stop, forwards/reverse cycles) to avoid internal shock loads in the gear mesh. Having said that, with today’s high-image resolution motor-feedback gadgets and associated motion controllers it is easy to compensate for backlash anytime there exists a modify in the rotation or torque-load direction.
If, for the moment, we discount backlash, in that case what are the causes for selecting a more expensive, seemingly more technical planetary devices for servo gearheads? What positive aspects do planetary gears provide?
High Torque Density: Compact Design
An important requirement for automation applications is large torque capacity in a concise and light bundle. This excessive torque density requirement (a high torque/volume or torque/pounds ratio) is important for automation applications with changing large 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 implies a planetary equipment with state three planets can transfer 3 x the torque of an identical sized fixed axis “regular” 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 implies that the load is supported by N contacts (where N = quantity of planet gears) hence raising the torsional stiffness of the gearbox by aspect N. This implies it significantly lowers the lost movement compared to an identical size standard gearbox; and this is what is desired.
Low Inertia
Added inertia results within an further torque/energy requirement of both acceleration and deceleration. The smaller gears in planetary system cause lower inertia. In comparison to a same torque ranking standard gearbox, this is a good approximation to say that the planetary gearbox inertia is normally smaller by the square of the number of planets. Again, this advantage is definitely rooted in the distribution or “branching” of the load into multiple gear mesh locations.
High Speeds
Modern servomotors run at substantial rpm’s, hence a servo gearbox should be able to operate in a reliable manner at high suggestions speeds. For servomotors, 3,000 rpm is virtually the standard, and in fact speeds are continuously increasing as a way to optimize, increasingly complicated application requirements. Servomotors jogging at speeds more than 10,000 rpm aren’t unusual. From a rating viewpoint, with increased rate the power density of the engine increases proportionally without the real size boost of the engine or electronic drive. Thus, the amp rating stays a comparable while simply the voltage must be increased. A significant factor is in regards to the lubrication at excessive operating speeds. Fixed axis spur gears will exhibit lubrication “starvation” and quickly fail if operating at high speeds as the lubricant is definitely slung away. Only particular means such as costly pressurized forced lubrication devices can solve this issue. Grease lubrication is impractical as a result of its “tunneling effect,” where the grease, over time, is pushed apart and cannot flow back to the mesh.
In planetary systems the lubricant cannot escape. It really is consistently redistributed, “pushed and pulled” or “mixed” in to the gear contacts, ensuring secure lubrication practically in any mounting posture and at any speed. Furthermore, planetary gearboxes could be grease lubricated. This characteristic is usually inherent in planetary gearing due to the relative motion between different gears creating the arrangement.
THE VERY BEST ‘Balanced’ Planetary Ratio from a Torque Density Viewpoint
For less complicated computation, it is favored that the planetary gearbox ratio is an precise integer (3, 4, 6…). Since we are so used to the decimal program, we tend to use 10:1 despite the fact that it has no practical advantages for the pc/servo/motion controller. Actually, as we will have, 10:1 or higher ratios will be the weakest, using minimal “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. Almost all the epicyclical gears used in servo applications happen to be of the simple planetary design. Number 2a illustrates a cross-section of such a planetary gear set up with its central sun gear, multiple planets (3), and the ring gear. This is of the ratio of a planetary gearbox demonstrated in the shape is obtained straight from the initial kinematics of the system. It is obvious a 2:1 ratio isn’t possible in a straightforward planetary gear program, since to satisfy the prior equation for a ratio of 2:1, the sun gear would have to have the same diameter as the ring gear. Figure 2b shows the sun gear size for several ratios. With an increase of ratio the sun gear diameter (size) is decreasing.
Since gear size impacts loadability, the ratio is a solid and direct effect to the torque rating. Figure 3a displays the gears in a 3:1, 4:1, and 10:1 straightforward system. At 3:1 ratio, the sun gear is huge and the planets will be small. The planets are becoming “skinny walled”, limiting the space for the planet bearings and carrier pins, consequently limiting the loadability. The 4:1 ratio is a well-well-balanced ratio, with sunlight and planets getting the same size. 5:1 and 6:1 ratios still yield pretty good balanced equipment sizes between planets and sunlight. With bigger ratios approaching 10:1, the tiny sun gear becomes a solid limiting aspect for the transferable torque. Simple planetary models with 10:1 ratios have really small sun gears, which sharply restrictions torque rating.
How Positioning Reliability and Repeatability is Affected by the Precision and Top 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 product quality or precision. The fact is that the backlash possesses practically nothing to perform with the quality or accuracy of a gear. Just the consistency of the backlash can be viewed as, up to certain degree, a form of way of measuring gear top quality. From the application point of view the relevant concern is, “What gear properties are influencing the accuracy of the motion?”
Positioning accuracy is a measure of how specific a desired position is reached. In a shut loop system the prime determining/influencing factors of the positioning precision will be the accuracy and resolution of the feedback unit and where the location can be measured. If the positioning is normally measured at the final end result of the actuator, the influence of the mechanical parts could be practically eliminated. (Immediate position measurement can be used mainly in very high precision applications such as machine tools). In applications with a lesser positioning accuracy need, the feedback transmission is generated by a responses devise (resolver, encoder) in the electric motor. In cases like this auxiliary mechanical components attached to the motor such as a gearbox, couplings, pulleys, belts, etc. will impact the positioning accuracy.
We manufacture and design high-quality gears and complete speed-reduction devices. For build-to-print customized parts, assemblies, style, engineering and manufacturing solutions contact our engineering group.
Speed reducers and equipment trains can be classified according to gear type in addition to 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
proper angle and dual productivity right angle planetary gearheads
We realize you might not be interested in choosing the ready-to-use swiftness reducer. For those of you who want to design your personal special gear coach or speed reducer we give you a broad range of precision gears, types, sizes and material, available from stock.