Precision precision planetary gearbox Planetary Gearheads
The primary reason to use a gearhead is that it makes it possible to control a huge load inertia with a comparatively small motor inertia. Without the gearhead, acceleration or velocity control of the strain would require that the motor torque, and thus current, would need to be as much times higher as the decrease ratio which can be used. Moog offers an array of windings in each body size that, combined with a selection of reduction ratios, offers an assortment of solution to result requirements. Each combination of motor and gearhead offers exclusive advantages.
Precision Planetary Gearheads
32 mm LOW PRICED Planetary Gearhead
32 mm Precision Planetary Gearhead
52 mm Precision Planetary Gearhead
62 mm Precision Planetary Gearhead
81 mm Precision Planetary Gearhead
120 mm Precision Planetary Gearhead
Precision planetary gearhead.
Series P high precision inline planetary servo travel will satisfy your most demanding automation applications. The compact style, universal housing with accuracy bearings and precision planetary gearing provides high torque density and will be offering high positioning overall performance. Series P offers exact ratios from 3:1 through 40:1 with the highest efficiency and cheapest backlash in the industry.
Sizes: 60, 90, 115, 140, 180 and 220
Result Torque: Up to 1 1,500 Nm (13,275 lb.in.)
Gear Ratios: Up to 100:1 in two stages
Input Options: Matches any servo motor
Output Options: Outcome with or without keyway
Due to the load sharing characteristics 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 perfect for servo applications
Accurate helical technology provides increased tooth to tooth contact ratio by 33% versus. spur gearing 12¡ helix angle produces clean and quiet operation
One piece world carrier and end result shaft design reduces backlash
Single step machining process
Assures 100% concentricity Enhances torsional rigidity
Efficient lubrication forever
The great precision PS-series inline helical planetary gearheads are available in 60-220mm frame sizes and offer high torque, substantial radial loads, low backlash, great input speeds and a tiny package size. Custom versions are possible
Print Product Overview
Ever-Power PS-series gearheads provide the highest performance to meet up your applications torque, inertia, speed and reliability requirements. Helical gears give smooth and quiet procedure and create higher power density while keeping a small envelope size. Obtainable in multiple framework sizes and ratios to meet up many different application requirements.
• Industrial automation
• Semiconductor and electronics
• Food and beverage
• Health and beauty
• Life science
Features and Benefits
• Helical gears provide even more torque ability, lower backlash, and silent operation
• Ring gear slice into housing provides increased torsional stiffness
• Widely spaced angular get in touch with bearings provide output shaft with substantial radial and axial load capability
• Plasma nitride heat therapy for gears for good surface use and shear strength
• Sealed to IP65 to safeguard against harsh environments
• Mounting packages for direct and easy assembly to a huge selection of different motors
• Antenna pedestals
• Robotic actuation and propulsion
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 Rate (RPM)6000
AMOUNT OF PROTECTION (IP)IP65
EFFICIENCY For NOMINAL TORQUE (%)94 – 97
CUSTOM VERSIONS AVAILABLEYes
The Planetary (Epicyclical) Gear System as the “Program of preference” for Servo Gearheads
Consistent 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 can be a measure of the precision of the planetary gearbox.
The truth is, fixed-axis, standard, “spur” gear arrangement systems can be designed and created simply as easily for low backlash requirements. Furthermore, low backlash is not an absolute requirement of servo-primarily based automation applications. A moderately low backlash is a good idea (in applications with very high start/stop, onward/reverse cycles) in order to avoid internal shock loads in the apparatus mesh. That said, with today’s high-resolution motor-feedback devices and associated movement controllers it is easy to compensate for backlash anytime you will find a change in the rotation or torque-load direction.
If, for the moment, we discount backlash, after that what are the factors for selecting a more expensive, seemingly more technical planetary systems for servo gearheads? What positive aspects do planetary gears offer?
High Torque Density: Compact Design
An important requirement for automation applications is high torque capacity in a concise and light bundle. This huge torque density requirement (a higher torque/quantity or torque/pounds ratio) is very important to 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 3 x the torque of a similar sized fixed axis “standard” spur gear system
Great rotational (torsional) stiffness, or minimized elastic windup, is very important to applications with elevated positioning accuracy and repeatability requirements; especially under fluctuating loading circumstances. The strain distribution unto multiple gear mesh points implies that the load is reinforced by N contacts (where N = amount of planet gears) consequently increasing the torsional stiffness of the gearbox by point N. This means it substantially lowers the lost action compared to an identical size standard gearbox; which is what’s desired.
Added inertia results within an additional torque/energy requirement of both acceleration and deceleration. Small gears in planetary program result in lower inertia. Compared to a same torque ranking standard gearbox, this is a reasonable approximation to say that the planetary gearbox inertia is usually smaller by the square of the amount of planets. 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 trusted manner at high insight speeds. For servomotors, 3,000 rpm is virtually the standard, and actually speeds are continuously increasing in order to optimize, increasingly complex application requirements. Servomotors running at speeds in excess of 10,000 rpm are not unusual. From a score viewpoint, with increased quickness the energy density of the electric motor increases proportionally without the real size increase of the motor or electronic drive. Thus, the amp rating stays a comparable while simply the voltage should be increased. A key point is in regards to the lubrication at high operating speeds. Fixed axis spur gears will exhibit lubrication “starvation” and quickly fail if running at high speeds because the lubricant is definitely slung away. Only particular means such as expensive pressurized forced lubrication systems can solve this issue. Grease lubrication is certainly impractical because of its “tunneling effect,” in which the grease, as time passes, is pushed away and cannot stream back into the mesh.
In planetary systems the lubricant cannot escape. It really is continuously redistributed, “pushed and pulled” or “mixed” in to the gear contacts, ensuring safe lubrication practically in any mounting location and at any speed. Furthermore, planetary gearboxes could be grease lubricated. This feature is definitely inherent in planetary gearing due to the relative movement between the several gears making up the arrangement.
The Best ‘Balanced’ Planetary Ratio from a Torque Density Perspective
For much easier computation, it is desired that the planetary gearbox ratio is an exact integer (3, 4, 6…). Since we are very much accustomed to the decimal program, we tend to use 10:1 even though it has no practical gain for the pc/servo/motion controller. In fact, as we will see, 10:1 or higher ratios are the weakest, using the least “balanced” size gears, and hence have the lowest 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 used in servo applications will be of this simple planetary design. Determine 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 demonstrated in the figure is obtained straight from the unique kinematics of the system. It is obvious that a 2:1 ratio isn’t possible in a simple planetary gear system, since to satisfy the previous equation for a ratio of 2:1, the sun gear would have to possess the same diameter as the ring equipment. Figure 2b shows sunlight gear size for several 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 influence to the torque ranking. Figure 3a displays the gears in a 3:1, 4:1, and 10:1 straightforward system. At 3:1 ratio, sunlight gear is significant and the planets happen to be small. The planets have become “thin walled”, limiting the space for the planet bearings and carrier pins, consequently limiting the loadability. The 4:1 ratio is normally a well-balanced ratio, with sunlight and planets having the same size. 5:1 and 6:1 ratios still yield quite good balanced equipment sizes between planets and sunlight. With bigger ratios approaching 10:1, the small sun gear becomes a strong limiting component for the transferable torque. Simple planetary models with 10:1 ratios have really small sunlight gears, which sharply limitations torque rating.
How Positioning Precision and Repeatability is Affected by 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 truth is that the backlash features practically nothing to perform with the product quality or precision of a gear. Only the regularity of the backlash can be viewed as, up to certain degree, a form of way of measuring gear top quality. From the application perspective the relevant concern is, “What gear homes are influencing the accuracy of the motion?”
Positioning precision is a measure of how exact a desired situation is reached. In a closed loop system the prime determining/influencing elements of the positioning accuracy will be the accuracy and resolution of the feedback system and where the job can be measured. If the positioning is definitely measured at the ultimate outcome of the actuator, the influence of the mechanical elements can be practically eliminated. (Direct position measurement is used mainly in very high precision applications such as for example machine tools). In applications with a lower positioning accuracy necessity, the feedback transmission is produced by a responses devise (resolver, encoder) in the motor. In this instance auxiliary mechanical components attached to the motor like 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 offerings speak to our engineering group.
Speed reducers and equipment trains can be categorized according to gear type in addition to relative position of suggestions and productivity 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 not be interested in choosing the ready-to-use rate reducer. For those of you who want to design your unique special gear train or swiftness reducer we give a broad range of precision gears, types, sizes and material, available from stock.
precision planetary gearbox
Precision precision planetary gearbox Planetary Gearheads