precision planetary gearbox

Precision Planetary Gearheads
The primary reason to employ a gearhead is that it creates it possible to control a big 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 need to be as many times higher as the reduction ratio which is used. Moog offers an array of windings in each body size that, coupled with a selection of reduction ratios, offers an assortment of solution to output requirements. Each combination of electric motor and gearhead offers completely unique advantages.
Precision Planetary Gearheads
gearheads
32 mm Low Cost Planetary Gearhead
32 mm Precision Planetary Gearhead
52 mm Accuracy Planetary Gearhead
62 mm Accuracy Planetary Gearhead
81 mm Precision Planetary Gearhead
120 mm Precision Planetary Gearhead
Precision planetary gearhead.
Series P high precision inline planetary servo travel will fulfill your most demanding automation applications. The compact style, universal housing with accuracy bearings and accuracy planetary gearing provides large precision planetary gearbox torque density and will be offering high positioning overall 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
Output 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: End result with or without keyway
Product Features
Because of the load sharing features of multiple tooth contacts,planetary gearboxes provide the highest torque and stiffness for just about any given envelope
Balanced planetary kinematics in high speeds combined with associated load sharing make planetary-type gearheads perfect for servo applications
True helical technology provides increased tooth to tooth contact ratio by 33% versus. spur gearing 12¡ helix angle produces easy 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 forever
The great precision PS-series inline helical planetary gearheads can be found in 60-220mm frame sizes and provide high torque, large radial loads, low backlash, large input speeds and a little package size. Custom editions are possible
Print Product Overview
Ever-Power PS-series gearheads supply the highest overall performance to meet up your applications torque, inertia, speed and precision requirements. Helical gears present smooth and quiet operation and create higher electricity density while retaining a small envelope size. Obtainable in multiple framework sizes and ratios to meet 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 more torque ability, lower backlash, and quiet operation
• Ring gear cut into housing provides greater torsional stiffness
• Widely spaced angular speak to bearings provide result shaft with huge radial and axial load capability
• Plasma nitride heat treatment for gears for exceptional surface use and shear strength
• Sealed to IP65 to protect against harsh environments
• Mounting products for direct and easy assembly to a huge selection 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 Acceleration (RPM)6000
DEGREE OF PROTECTION (IP)IP65
EFFICIENCY For NOMINAL TORQUE (%)94 – 97
CUSTOM VERSIONS AVAILABLEYes
The Planetary (Epicyclical) Gear System as the “System of Choice” for Servo Gearheads
Repeated misconceptions regarding planetary gears systems involve backlash: Planetary systems are being used for servo gearheads due to their inherent low backlash; low backlash is definitely the main characteristic requirement for 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 can be designed and built simply as easily for low backlash requirements. Furthermore, low backlash is not an absolute requirement for servo-established automation applications. A moderately low backlash is recommended (in applications with very high start/stop, ahead/reverse cycles) in order to avoid inner shock loads in the gear mesh. That said, with today’s high-image resolution motor-feedback devices and associated action controllers it is easy to compensate for backlash anytime there is a transform in the rotation or torque-load direction.
If, for as soon as, we discount backlash, in that case what are the reasons for selecting a more expensive, seemingly more complex planetary devices for servo gearheads? What advantages do planetary gears present?
High Torque Density: Small Design
An important requirement for automation applications is high torque capacity in a concise and light bundle. This great torque density requirement (a higher torque/quantity or torque/excess weight ratio) is important for automation applications with changing substantial dynamic loads in order to avoid additional system inertia.
Depending upon the number of planets, planetary systems distribute the transferred torque through multiple equipment mesh points. This implies a planetary equipment with claim three planets can transfer three times the torque of a similar sized fixed axis “regular” spur gear system
Rotational Stiffness/Elasticity
Huge rotational (torsional) stiffness, or minimized elastic windup, is very important to applications with elevated positioning accuracy and repeatability requirements; specifically under fluctuating loading circumstances. The strain distribution unto multiple equipment mesh points signifies that the load is supported by N contacts (where N = quantity of planet gears) consequently raising the torsional stiffness of the gearbox by element N. This implies it considerably lowers the lost motion compared to an identical size standard gearbox; and this is what’s desired.
Low Inertia
Added inertia results in an added torque/energy requirement for both acceleration and deceleration. Small gears in planetary program bring about lower inertia. In comparison to a same torque score standard gearbox, it is a good approximation to say that the planetary gearbox inertia is smaller by the square of the number of planets. Once again, this advantage is normally rooted in the distribution or “branching” of the load into multiple gear mesh locations.
High Speeds
Modern servomotors run at excessive rpm’s, hence a servo gearbox should be able to operate in a reliable manner at high type speeds. For servomotors, 3,000 rpm is practically the standard, and in fact speeds are continuously increasing to be able to optimize, increasingly sophisticated application requirements. Servomotors running at speeds in excess of 10,000 rpm aren’t unusual. From a rating perspective, with increased acceleration the energy density of the engine increases proportionally with no real size enhance of the electric motor or electronic drive. As a result, the amp rating stays a comparable while just the voltage should be increased. A key point is in regards to the lubrication at huge operating speeds. Set axis spur gears will exhibit lubrication “starvation” and quickly fail if operating at high speeds for the reason that lubricant is normally slung away. Only unique means such as expensive pressurized forced lubrication devices can solve this problem. Grease lubrication can be impractical due to its “tunneling effect,” in which the grease, over time, is pushed aside and cannot flow back into the mesh.
In planetary systems the lubricant cannot escape. It is constantly redistributed, “pushed and pulled” or “mixed” in to the gear contacts, ensuring secure lubrication practically in any mounting job and at any velocity. Furthermore, planetary gearboxes could be grease lubricated. This feature is inherent in planetary gearing because of the relative movement between the various gears creating the arrangement.
THE VERY BEST ‘Balanced’ Planetary Ratio from a Torque Density Point of View
For simpler computation, it is favored that the planetary gearbox ratio can be an actual integer (3, 4, 6…). Since we are very much accustomed to the decimal system, we tend to use 10:1 even though this has no practical benefits for the pc/servo/motion controller. Truly, as we will see, 10:1 or higher ratios are the weakest, using the least “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. The vast majority of the epicyclical gears found in servo applications happen to be of this simple planetary design. Figure 2a illustrates a cross-section of such a planetary gear set up with its central sun equipment, multiple planets (3), and the ring gear. This is of the ratio of a planetary gearbox proven in the determine is obtained immediately 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 have the same size as the ring equipment. Figure 2b shows the sun gear size for unique ratios. With increased ratio sunlight gear diameter (size) is decreasing.
Since gear size impacts loadability, the ratio is a strong and direct influence to the torque score. Figure 3a shows the gears in a 3:1, 4:1, and 10:1 simple system. At 3:1 ratio, sunlight gear is huge and the planets will be small. The planets have become “slim walled”, limiting the area for the planet bearings and carrier pins, hence limiting the loadability. The 4:1 ratio can be a well-well balanced ratio, with sunshine 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 tiny sun equipment becomes a strong limiting point for the transferable torque. Simple planetary styles with 10:1 ratios have very small sunlight gears, which sharply limitations torque rating.
How Positioning Precision and Repeatability is Affected by the Precision and Quality Class of the Servo Gearhead
As previously mentioned, this 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 offers practically nothing to perform with the quality or accuracy of a gear. Only the regularity of the backlash can be viewed as, up to certain level, a form of measure of gear top quality. From the application perspective the relevant query is, “What gear real estate are influencing the accuracy of the motion?”
Positioning precision is a measure of how exact a desired job is reached. In a closed loop system the primary determining/influencing factors of the positioning precision are the accuracy and quality of the feedback device and where the placement is certainly measured. If the position is definitely measured at the final outcome of the actuator, the effect of the mechanical components can be practically eliminated. (Immediate position measurement is used mainly in high precision applications such as machine equipment). In applications with less positioning accuracy need, the feedback signal is produced by a feedback devise (resolver, encoder) in the electric motor. In this case auxiliary mechanical components attached to the motor for instance a gearbox, couplings, pulleys, belts, etc. will influence the positioning accuracy.
We manufacture and design high-quality gears together with complete speed-reduction devices. For build-to-print customized parts, assemblies, style, engineering and manufacturing products and services speak to our engineering group.
Speed reducers and gear trains can be classified according to gear type as well as relative position of insight and result shafts. SDP/SI offers a multitude of standard catalog items:
gearheads and speed reducers
planetary and spur gearheads
proper angle and dual outcome right angle planetary gearheads
We realize you may well not be interested in selecting a ready-to-use rate reducer. For those of you who want to design your individual special gear educate or quickness reducer we give you a broad range of accuracy gears, types, sizes and materials, available from stock.