Model Dual Function Planetary Gear Reducer

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Ethelbert Webb
5 years ago
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1 Model 3210 Dual Function Planetary Gear Reducer

2 I. OVERVIEW The Model 3210 Planetary Gear Reducer is an extremely robust, dual function power transmission device that combines a conventional (in line) planetary gear reducer with a secondary spur gear reduction. Each reducing function is driven by a separate input shaft each having its own reduction ratio. A unique gear arrangement causes the rotation of the output shaft to equal the sum of the rotation of the two input shafts times the reduction ratio of each gear set. This allows the system to which the reducer is applied to be driven by two motors each operating a different reduction ratio. Use of the Model 3210 allows for the optimization of a drive system employed in an actuation system where the force vs. speed requirement varies significantly during different portions of the motion profile. Drive optimization can save thousands of dollars over using a single motor/drive sized to provide both high speed and high torque. Speed Force Position II. Applications Applications for the Dual Function Gear Reducer are numerous and varied. The following are common applications where the 3210 Model provides ideal solutions. Pressing, Mold Closing, Forming A frequent application for the Model 3210 is pressing, wether it be assembling parts, closing a mold or forming and shaping objects. The Model 3210 is particularly valuable when the cycle time is a critical factor for a successful implementation or electro-mechanical pressing system. A typical pressing motion cycle involves moving the work piece at high speed in order to close the press or mold at which point the pressing or forming process begins. Once the pressing process is complete the press typically opens at high speed. The opening and closing motion, while required to load or unload the part, is non-productive cycle time. This can be minimized by making this portion of the cycle occur in as short a time as possible. Generally the torque driving the high-speed portion of the actuator s motion is relatively small compared to the pressing or working torque, therefore, the optimal drive for this portion of the cycle is configured for speed instead of torque. The Pressing portion of the application usually involves high torque. The torque is required to create the high forces necessary to work the load. Typical speed requirements are low for the high force portion of the move and in many cases the working move is short. Therefore the optimal drive for this part of the cycle produces high torque as opposed to speed. Utilizing a single servo system for these types of applications, will require that both the servo motor and the servo amplifier be sized to deliver power capability calculated to cover both ends of the power spectrum high speed/low force as well as high force/low speed. This frequently leads to the selection of a drive system which is rated for much higher power then is actually needed to perform the two contrary move segments. Moreover the electric power distribution system must be built to deliver the power of the rated system as opposed to power actually consumed at any moment. As a result the cost of using a single drive system escalates even though only a fraction of its capability is used during the cycle at any moment. In addition, overall system perforamce may be sacrificed in order to live with cost limitations. All information in this brochure is preliminary. 1

Using the model 3210 Dual Function Gear Reducer allows the system designer to separate the motion into two parts allowing the implementation of a high-speed servo system separately from the high

This combination dramatically reduces system cost and can reduce cycle time as system performance is optimized.

are specified to minimize cycle time. Using a single drive solution for this application will require 40 horsepower, making the price of the drive system around $20,000.

The rating of the high speed and high torque drive is now 6.7 hp and 5.3 hp respectively each running around $5,500.

3 Using the model 3210 Dual Function Gear Reducer allows the system designer to separate the motion into two parts allowing the implementation of a high-speed servo system separately from the high force system. Use of two small servo drives allow optimization of each drive in terms of the speed and torque (and thus power) required for its portion of the pressing cycle. This combination dramatically reduces system cost and can reduce cycle time as system performance is optimized. A practical example can be seen in an application where a pressing system produces a force of 20,000 lbs. to deform a fastener during a.14 in. pressing move. Opening and closing speeds of 20 in./sec. are specified to minimize cycle time. Using a single drive solution for this application will require 40 horsepower, making the price of the drive system around $20,000. By applying a Model 3210 Dual Function Gear Reducer on the input of the actuator, the motion can be split between two smaller, less expensive drives. The rating of the high speed and high torque drive is now 6.7 hp and 5.3 hp respectively each running around $5,500. In addition, since the combined power requirement is substantially smaller the rating of the electrical power distribution system is reduced from 30 KW to 12 kw, providing an additional saving estimated around $4,000. SERVO SYSTEM PRICE VS POWER In most cases the overall size and weight of the actuator/motor system is reduced with the Model 3210 Gear Reducer. Traditional Single Servo system System using Model 3210 Dual Function Gear Reducer As a result, the model 3210 Dual Function Gear Reducer poses a cost effective and reliable solution for applications which include pressing, molding and forming applications where cycle time is critical and installed cost, size, and weight are important. Phase Shifting Other applications which are ideally suited for the 3210 Gear Reducer include phase shifting of two rotating shafts. Rotation of the secondary shaft causes the output shaft of the 3210 to change its rotational position relative to the primary input shaft. This occurs while stopped or while operating and allows the user to control the phase relationship between the input shaft and output shaft. Redundant Drive The Model 3210 Dual Function Gear Reducer allows a secondary motor to drive a system when the primary drive fails or is held in position. This could be accomplished manually using a hand wheel or automatically by incorporating a back up drive system. All information in this brochure is preliminary. 2

III. Operation Dual Reduction The primary input shaft of the Model 3210 drives a sun gear which in turn causes a set of three gears arranged in a planetary configuration to rotate.

A single piece, fully caged planet carrier holds the planet gears and rotates as the input shaft is turned.

relative size of the sun and planet gears.

This rotatable ring gear possesses gear teeth on the outside of the ring as well as the inside.

4 III. Operation Dual Reduction The primary input shaft of the Model 3210 drives a sun gear which in turn causes a set of three gears arranged in a planetary configuration to rotate. These rotate around the sun gear as their teeth engage with a ring gear located around the exterior of this arrangement. A single piece, fully caged planet carrier holds the planet gears and rotates as the input shaft is turned. The planet carrier is machined as a single piece with the output shaft causing it to rotate in the same direction as the input shaft but with a reduction ranging from 3:1 to 10:1 depending on the relative size of the sun and planet gears. Secondary Input Shaft Primary Input Shaft Planet Gears Spur Gear Carrier Sun Gear Output Shaft A unique feature of the Model 3210 reducer allows the ring gear to rotate. This rotatable ring gear possesses gear teeth on the outside of the ring as well as the inside. The inside teeth mesh with the internal planets while the outside teeth mesh with a separately mounted spur gear driven by the secondary input shaft. This effectively provides a secondary gear reduction which is independent of the primary reduction. The secondary input shaft can be either held from rotating or rotated in either direction at the same time as the primary input shaft. In all cases the output rotation is the sum total of the rotation of the two input shafts times their respective reduction ratios. Backdrive Prevention In applications where there exists considerate difference (ex: 10:1 and 3:1) in the reduction ratios of the two reductors, torque applied to the secondary shaft may apply a very high back driving force on the primary input shaft. If the applied torque is high enough it will overcome the primary motor s ability to control this shaft. An optional back drive prevention mechanism is available that prohibits the primary input shaft from back driving when the parallel input shaft is transmitting torque. This allows very rapid rotation of the output shaft (3:1 reduction) during the low output torque portion of a move while delivering very high torque (up to 30:1 single stage reduction) during the pressing or holding portion of a move. All information in this brochure is preliminary. 3

IV. Mounting The Model 3210 Dual Function Gear Reducer is available in four

Stand Alone This configuration is designed such that the gear box can be mounted

couplings. Mounting patterns conform to IEC standards. 2.

housing assembly normally provided with universal electric actuators.

the parallel mounting both motors face forward.

5 IV. Mounting The Model 3210 Dual Function Gear Reducer is available in four different mounting configuration. 1. Stand Alone This configuration is designed such that the gear box can be mounted on its own or attached to another mechanism by mounting bolts and shaft couplings. Mounting patterns conform to IEC standards. 2. Actuator Mounting Actuator mounting is intended to replace the back pulleys and housing assembly normally provided with universal electric actuators. In this way the overall footprint and weight of the reducer and actuator is minimized. Two different universal actuator mounting configurations are available. a. Parallel Shafts: This style mounts to the input of any universal actuator in one of two different ways. With in line mounting the two motors face towards the rear of the actuator with the parallel mounting both motors face forward. In Line Mounting: Parallel Mounting: b. Opposing Shafts: This configuration has one motor facing the rear and one facing forward. This configuration minimizes the center distances of the two input shafts even when the motors would normally interfere with each other. This creates the most compact cross-section of the three configurations available. Opposing Shaft Mounting: All information in this brochure is preliminary. 4

V. Sizes The Model 3210 Dual Function Gear Reducer is available in six different frame sizes allowing the complex drive functions to be applied to varying size loads: 60mm 75mm 90mm 115mm 142mm 180mm

Nominal Output Torque Secondary reduction ratios available Nm Primary Reduction Ratio RK060 RK75 RK090 RK115 RK142 RK180 3 55 130 208 342 588 4 50 140 290 542 1050 5 60 160 330 650 1200 7 50 140 300

6 V. Sizes The Model 3210 Dual Function Gear Reducer is available in six different frame sizes allowing the complex drive functions to be applied to varying size loads: 60mm 75mm 90mm 115mm 142mm 180mm VI. Specifications 1. General Specifications Input Motor Shaft Interfaces: Clamp collar, keyway External Material case: Aluminum Shaft: stainless steel Model No. Nominal Output Torque Secondary reduction ratios available Nm Primary Reduction Ratio RK060 RK75 RK090 RK115 RK142 RK Emergency Stop Torque Nm 3 times of Nominal Output Torque Max. Input Speed (Primary Input shaft) rpm Max. Input Speed (Secondary Input shaft) rpm 10,000 8,000 8,000 6,000 6,000 Torsional Rigidity Nm/arcmin Max. Radial Load F 2rB N Max Axial Load 2aB N Service Life hr. 20,000* Efficiency ƞ % 97% 94% Weight kg Operating Temp C -10C ~90C Lubrication Degree of Gearbox Protection Mounting Position Grease IP65 all directions Noise Level (n 1=3000rpm, No Load) db(a) Model No. Moment of Inertia J 1 kg! cm 2 Ratio RK060 RK75 RK090 RK115 RK142 RK Ratio (i=n in/n out) 2. Max. acceleration torque T 2B = 60% of T2NOT 3. Applied to the output shaft 100rpm All information in this brochure is preliminary. 5

7 VII. Dimensions Dimension Frame Size (mm) A B C D D E F All information in this brochure is preliminary. 6

8 Riekor Corporation 7626 Executive Drive Eden Prairie, MN

TS Series Return-to-Home Gear Reducer

TS Series Return-to-Home Gear Reducer I. OVERVIEW The TS Series Return-to-Home Gear Reducer is a high accuracy, high reliability in-line gear reducer that combines a conventional planetary gear set with