precision planetary gearbox

Precision Planetary Gearheads
The primary reason to employ a gearhead is that it makes 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 thus current, would need to be as much times better as the lowering ratio which can be used. Moog offers a selection of windings in each framework size that, combined with a selection of reduction ratios, provides an assortment of solution to outcome requirements. Each blend of electric motor and gearhead offers exceptional advantages.
Precision Planetary Gearheads
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 Accuracy Planetary Gearhead
Precision planetary gearhead.
Series P high precision inline planetary servo travel will meet your most demanding automation applications. The compact style, universal precision planetary gearbox housing with precision bearings and accuracy planetary gearing provides great torque density and will be offering high positioning overall performance. Series P offers actual ratios from 3:1 through 40:1 with the highest efficiency and lowest backlash in the market.
Key Features
Sizes: 60, 90, 115, 140, 180 and 220
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: Output with or without keyway
Product Features
As a result of load sharing features 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 generate planetary-type gearheads ideal for servo applications
Accurate 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 result shaft design reduces backlash
Single step machining process
Assures 100% concentricity Raises torsional rigidity
Efficient lubrication for life
The great precision PS-series inline helical planetary gearheads can be found in 60-220mm frame sizes and offer high torque, substantial radial loads, low backlash, great input speeds and a small package size. Custom types are possible
Print Product Overview
Ever-Power PS-series gearheads provide the highest overall performance to meet up your applications torque, inertia, speed and accuracy requirements. Helical gears provide smooth and quiet operation and create higher power density while retaining a tiny envelope size. Obtainable in multiple framework sizes and ratios to meet up various 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 quiet operation
• Ring gear trim into housing provides higher torsional stiffness
• Widely spaced angular speak to bearings provide end result shaft with large radial and axial load capability
• Plasma nitride heat therapy for gears for wonderful surface put on and shear strength
• Sealed to IP65 to safeguard against harsh environments
• Mounting products 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 For NOMINAL TORQUE (%)94 – 97
CUSTOM VERSIONS AVAILABLEYes
The Planetary (Epicyclical) Gear System as the “System of preference” for Servo Gearheads
Repeated 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 of a servo gearboxes; backlash is normally a measure of the accuracy of the planetary gearbox.
The fact is, fixed-axis, standard, “spur” gear arrangement systems could be designed and constructed 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 recommended (in applications with very high start/stop, forwards/reverse cycles) in order to avoid internal shock loads in the apparatus mesh. That said, with today’s high-quality motor-feedback units and associated action controllers it is easy to compensate for backlash anytime there exists a change in the rotation or torque-load direction.
If, for as soon as, we discount backlash, after that what are the causes for selecting a even more expensive, seemingly more complex planetary systems for servo gearheads? What advantages do planetary gears provide?
High Torque Density: Compact Design
An important requirement of automation applications is huge torque capability in a concise and light bundle. This huge torque density requirement (a high torque/volume or torque/excess weight ratio) is important for automation applications with changing great dynamic loads to avoid additional system inertia.
Depending upon the quantity of planets, planetary devices distribute the transferred torque through multiple gear mesh points. This means a planetary equipment with say three planets can transfer three times the torque of an identical sized fixed axis “common” spur gear system
Rotational Stiffness/Elasticity
High rotational (torsional) stiffness, or minimized elastic windup, is important for applications with elevated positioning accuracy and repeatability requirements; specifically under fluctuating loading circumstances. The load distribution unto multiple equipment mesh points signifies that the load is backed by N contacts (where N = amount of planet gears) therefore raising the torsional stiffness of the gearbox by factor N. This implies it considerably lowers the lost movement compared to a similar size standard gearbox; which is what is desired.
Low Inertia
Added inertia results within an added torque/energy requirement of both acceleration and deceleration. Small gears in planetary program cause lower inertia. Compared to a same torque ranking standard gearbox, this is a reasonable approximation to state that the planetary gearbox inertia is usually smaller by the square of the amount of planets. Once again, this advantage is definitely rooted in the distribution or “branching” of the strain into multiple equipment mesh locations.
High Speeds
Modern servomotors run at huge rpm’s, hence a servo gearbox must be able to operate in a reliable manner at high insight speeds. For servomotors, 3,000 rpm is virtually the standard, and in fact speeds are continuously increasing so as to optimize, increasingly sophisticated application requirements. Servomotors operating at speeds in excess of 10,000 rpm aren’t unusual. From a ranking perspective, with increased velocity the energy density of the motor increases proportionally without the real size maximize of the engine or electronic drive. Therefore, the amp rating remains a comparable while only the voltage should be increased. A significant factor is in regards to the lubrication at substantial operating speeds. Fixed axis spur gears will exhibit lubrication “starvation” and quickly fail if running at high speeds as the lubricant is normally slung away. Only special means such as pricey pressurized forced lubrication systems can solve this issue. Grease lubrication is impractical due to its “tunneling effect,” where the grease, over time, is pushed aside and cannot circulation back to the mesh.
In planetary systems the lubricant cannot escape. It really is continuously redistributed, “pushed and pulled” or “mixed” in to the equipment contacts, ensuring safe lubrication practically in virtually any mounting placement and at any acceleration. Furthermore, planetary gearboxes could be grease lubricated. This characteristic is normally inherent in planetary gearing because of the relative movement between the various gears creating the arrangement.
The Best ‘Balanced’ Planetary Ratio from a Torque Density Viewpoint
For a lot easier computation, it is preferred that the planetary gearbox ratio is an exact integer (3, 4, 6…). Since we are very much accustomed to the decimal program, we have a tendency to use 10:1 despite the fact that it has no practical edge for the computer/servo/motion controller. Truly, as we will see, 10:1 or more ratios are 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 engaging 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 using its central sun equipment, multiple planets (3), and the ring gear. The definition of the ratio of a planetary gearbox displayed in the shape is obtained straight from the unique kinematics of the machine. It is obvious that a 2:1 ratio is not possible in a straightforward planetary gear system, 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 equipment. Figure 2b shows sunlight gear size for numerous ratios. With an increase of ratio the sun gear size (size) is decreasing.
Since gear size affects loadability, the ratio is a strong and direct impact to the torque ranking. Figure 3a displays the gears in a 3:1, 4:1, and 10:1 straightforward system. At 3:1 ratio, the sun gear is large and the planets will be small. The planets have become “slim walled”, limiting the space for the planet bearings and carrier pins, consequently limiting the loadability. The 4:1 ratio is usually 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 sun. With higher ratios approaching 10:1, the small sun equipment becomes a solid limiting issue for the transferable torque. Simple planetary styles with 10:1 ratios have really small sunlight gears, which sharply restrictions torque rating.
How Positioning Accuracy and Repeatability is Affected by the Precision and Top quality Course of the Servo Gearhead
As previously mentioned, this is a general misconception that the backlash of a gearbox is a way of measuring the quality or precision. The truth is that the backlash possesses practically nothing to do with the product quality or accuracy of a gear. Only 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 problem is, “What gear real estate are influencing the precision of the motion?”
Positioning reliability is a measure of how actual a desired job is reached. In a closed loop system the primary determining/influencing factors of the positioning reliability are the accuracy and resolution of the feedback product and where the position can be measured. If the position is definitely measured at the ultimate productivity of the actuator, the influence of the mechanical elements can be practically eliminated. (Immediate position measurement is employed mainly in high precision applications such as machine tools). In applications with a lesser positioning accuracy necessity, the feedback transmission is produced by a feedback devise (resolver, encoder) in the engine. In this instance auxiliary mechanical components attached to the motor like a gearbox, couplings, pulleys, belts, etc. will affect the positioning accuracy.
We manufacture and style high-quality gears as well as complete speed-reduction devices. For build-to-print customized parts, assemblies, style, engineering and manufacturing solutions contact our engineering group.
Speed reducers and gear trains can be classified according to equipment type together with relative position of source and end result shafts. SDP/SI offers a wide variety of standard catalog items:
gearheads and speed reducers
planetary and spur gearheads
right angle and dual outcome right angle planetary gearheads
We realize you may not be interested in selecting a ready-to-use acceleration reducer. For those of you who wish to design your very own special gear coach or quickness reducer we provide a broad range of accuracy gears, types, sizes and materials, available from stock.