Industrial Shock Absorbers (Linear Decelerators) Catalog AU08-1022/NA January, 2003 ■■■■■ Compact Designs ■■■■■ High Effective Weight Capability ■■■■■ Industry Interchangeable ■■■■■ Metric and UNF Threads ■■■■■ Complete Line of Accessories www.comoso.com Catalog AU08-1022/NA Industrial Shock Absorbers Quality Construction Linear Decelerators Parker Cylinder has not only established a reputation as the world leader in motion control technology, but in quality as well. The employees of Parker Hannifin are dedicated to building a quality product, assuring customer satisfaction, and delivering on time. As a result of this employee focus, Parker Hannifin shock absorbers are built to the highest standards. A majority of Parker shock absorber bodies and inner pressure chambers are fully machined from solid alloy steel. A completely closed-end, one-piece pressure chamber is provided without seals or retaining rings. The advantage of this design is that the Parker shock absorber is able to withstand much higher internal pressures or overload without damage, thereby providing a high Piston Rod - operational safety margin. high tensile steel The features listed on this page are representative of hardened and the rugged, dependable components that are built corrosion resistant into each Parker shock absorber. Main Bearing - system lubricated Mega Series MC 33 to 64 Piston Ring - hardened for long life Pressure Chamber - made from hardened alloy steel. Machined from solid with closed rear end to withstand internal pressures up to 14,500 psi (1000 bar). Outer Body - heavy-duty, one piece, fully machined from solid steel to ensure total reliability. Offer of Sale The items described in this document are hereby offered for sale by Parker Hannifin Corporation, its subsidiaries or its authorized distributors. This offer and its acceptance are governed by the provisions stated on the separate page of this document entitled ‘Offer of Sale’. WARNING FAILURE OR IMPROPER SELECTION OR IMPROPER USE OF THE PRODUCTS AND/OR SYSTEMS DESCRIBED HEREIN OR RELATED ITEMS CAN CAUSE DEATH, PERSONAL INJURY AND PROPERTY DAMAGE. This document and other information from Parker Hannifin Corporation, its subsidiaries and authorized distributors provide product and/or system options for further investigation by users having expertise. It is important that you analyze all aspects of your application, including consequences of any failure and review the information concerning the product or system in the current product catalog. Due to the variety of operating conditions and applications for these products or systems, the user, through its own analysis and testing, is solely responsible for making the final selection of the products and systems and assuring that all performance, safety and warning requirements of the application are met. The products described herein, including without limitation, product features, specifications, designs, availability and pricing, are subject to change by Parker Hannifin Corporation and its related companies at any time without notice. Parker Hannifin Corporation Des Plaines, IL USA Owen Sound, Ontario Canada www.comoso.com Catalog AU08-1022/NA Industrial Shock Absorbers Table of Contents Linear Decelerators Table of Contents Page No. Technical Information Features and Benefits ................................................................................................................................2 General Information....................................................................................................................................4 Deceleration Principles...............................................................................................................................6 Sizing Examples........................................................................................................................................8 Installation Examples...............................................................................................................................12 Model Rating Charts.................................................................................................................................14 Shock Absorber Selection – Self Compensated, Miniature MC9 - MC75 ............................................................................................................................................16 MC150 - MC600.......................................................................................................................................18 SC190 - SC925........................................................................................................................................20 SC300 - SC650, Heavy Weight Shock Absorbers......................................................................................22 Shock Absorber Selection – Adjustable, Miniature MA35 - MA900.........................................................................................................................................24 Mega Series Shocks MC, MA, ML 33 - 64.................................................................................................................................26 Large Bore Shock Absorbers 11/" Bore, Adjustable ...............................................................................................................................36 2 CA Series 2" - 4" Bore, Self Compensated and Adjustable........................................................................38 Accessories Miniature Shocks .....................................................................................................................................46 Mega Series Shocks................................................................................................................................50 Air Oil Tanks ............................................................................................................................................53 Offer of Sale.....................................................................................................................................................54 Parker Hannifin Corporation 1 Des Plaines, IL USA Owen Sound, Ontario Canada www.comoso.com Catalog AU08-1022/NA Industrial Shock Absorbers Features Linear Decelerators Miniature Shock Absorbers MC 9 to MC 75 Self-Compensating Miniature Shock Absorbers MC 150, MC 225 and MC 600 Self-Compensating Heavyweight Shock Absorbers SC 300 and SC 650 Soft Contact and Self-Compensating Miniature Shock Absorbers SC 190 to SC 925 Soft Contact and Self-Compensating Parker Hannifin Corporation 2 Des Plaines, IL USA Owen Sound, Ontario Canada www.comoso.com Catalog AU08-1022/NA Industrial Shock Absorbers Features Linear Decelerators MA Series 225-900 Shock Absorbers (Miniature Adjustable) Adjustable Mega Series MA and ML 33 to 64 Adjustable Heavy Industrial Shock Absorbers CA to CA 4 Self-Compensating Heavy Industrial Shock Absorbers A2 to A3 Adjustable Parker Hannifin Corporation 3 Des Plaines, IL USA Owen Sound, Ontario Canada www.comoso.com Catalog AU08-1022/NA Industrial Shock Absorbers General Information Linear Decelerators Comparison 1. Cylinder Cushions and Dashpots (High stopping force at start of the stroke). With only one metering orifice, the moving load is abruptly 1 slowed down at the start of the stroke. The braking force rises to a very high peak at the start of the stroke (giving high shock loads) and then falls away rapidly. 2. Springs and Rubber Bumpers (High stopping forces at end Force of stroke). 2 lbs. The moving load is slowed down by a constantly rising reaction (N) 3 force up to the point of full compression. These devices store energy rather than dissipate it, which causes the load to bounce back. 3. Industrial Shock Absorbers (Uniform stopping force through the entire stroke). The moving load is smoothly and gently brought to rest by a constant resisting force throughout the entire shock absorber stroke.The load is decelerated with the lowest Stopping Stroke possible force, in the shortest possible time, eliminating damag- ing force peaks and shock damage to machines and equipment. This is a linear deceleration force stroke curve and is the curve provided by industrial shock absorbers. Energy Capacity Reaction Force Stopping Time (stopping force) Shock Absorber Hydraulic Dashpot Shock Absorber t Q Force Force Shock Absorber v lbs Hydraulic lbs ft/s t (N) Dashpot (N) (m/s) Hydraulic Dashpot Q Stopping Stroke Stopping Stroke Stopping Time Premise: Premise: Premise: Same maximum reaction force. Same energy absorption Same energy absorption. (area under the curve). Result: Result: Result: The shock absorber can absorb The reaction force transmitted The shock absorber stops considerably more energy by the shock absorber is the moving load in a much (represented by the area under very much lower. shorter time. the curve.) Benefit: Benefit: Benefit: By installing a shock absorber By installing the shock By installing a shock production rates can be more absorber the machine wear absorber cycle times are than doubled without increasing and maintenance can be reduced giving much higher deceleration forces or reaction drastically reduced. production rates. forces on the machine. Parker Hannifin Corporation 4 Des Plaines, IL USA Owen Sound, Ontario Canada www.comoso.com Catalog AU08-1022/NA Industrial Shock Absorbers General Information Linear Decelerators The use of one piece / closed end bodies and inner pressure chambers provides an extremely strong construction, which can withstand much higher internal pressures and overload forces without mechanical damage. Consider what happens if the shock absorber is accidentally overloaded or in the unlikely event of partial oil loss due to excessive seal wear or damage. Compare the internal design used by Parker with that of some of its competitors: Parker Shock Absorber Other Shock Absorber Outer body and pressure chamber Snap Ring (Outer body and inner with closed rear end (one-piece) pressure chamber made from tube stock.) Parker builds its shock absorbers with closed end/one Some other manufacturers use bodies and inner pressure piece bodies and inner pressure chambers, which greatly chambers made from tube stock.The internal parts are held reduces the chance of sudden failure, or machine damage in by a snap ring etc. which then takes all the load and can in the event of an overload. fail suddenly and catastrophically. What happens with an overload or gradual oil loss? What happens with an overload or gradual oil loss? Harder bottoming out force becomes apparent. The snap ring breaks or is extruded due to excessive force. The shock absorber continues to work and can be re- Machine damage!! Equipment Stops!! placed then or at the end of the shift. Production Halted!! Emergency Repair!! Corrective Action: Corrective Action: Remove and replace the shock absorber. Refill with fresh Remove and replace the shock absorber with new one oil or repair. (repair not possible). * As a moving load impacts the shock absorber, the piston travels through stroke and forces hydraulic fluid through the multi-orifice inner tube. The total orifice area decreases at a rate consistent with the decay of impact velocity, resulting in true linear deceleration. F = Force lbs (N) P= Internal pressure psi (bar) s = Stroke in (m) t = Deceleration time (s) v = Velocity ft/s (m/s) Parker Hannifin Corporation 5 Des Plaines, IL USA Owen Sound, Ontario Canada www.comoso.com Catalog AU08-1022/NA Industrial Shock Absorbers Deceleration Principles: Effective Weight Linear Decelerators Effective weight is an important factor in selecting shock Figure A absorbers. A shock absorber “sees” the impact of an object in terms of weight and velocity only; it does not ”see” any propelling force. The effective weight can be thought of as the weight that the shock absorber “sees” on impact. Effective weight includes the effect of the propelling force on the performance of the shock absorber. Failing to consider the effective weight may result in improper selection and poor performance of the shock absorber. Under extreme conditions, an effective weight that is too low may result in high forces at the start of stroke (high on-set force). However, an effective weight that is too high for the shock absorber may cause high forces at the end of stroke (high set-down force). Figure B Consider the following examples: 1.)A 5 lb (2.27 kg) weight travelling at 25 ft/sec (7.62 m/s) has 625 lbs (71 Nm) of kinetic energy (Figure A). On this basis alone, an MA 3325 would be selected. However, because there is no propelling force, the calculated effective weight is five pounds – which is below the effective weight range of the standard MA 3325. This is a high on-set force at the start of the stroke (Figure B). The solution is to use a specially-orificed shock absorber to handle the load. 2.)A weight of 50 lbs (22.68 kg) has an impact velocity of 0.5 ft/sec (0.15 m/s) with a propelling force of 800 lbs (111N) (Figure C). The total impact energy is 802.5 inch-pounds. Again, an MA 3325 would be selected based just on the energy. The effective weight is calculated to be 16,050 Figure C pounds (7,280 kg). This is well above the range of the standard MA 3325. If this shock absorber is used, high- set-down forces will result (Figure D). In this case, the solution is to use a ML 3325, which is designed to work in low-velocity, high-effective weight applications. Computer-Aided Simulation Figure D By combining application data with a shock absorbers design parameters, Parker engineers can create a picture of how the shock will perform when impacted by the application load. Peak reaction force, peak deceleration (G’s), time through stroke, and velocity decay are identified with extreme accuracy. The user benefits by having the guesswork taken out of sizing decisions and by knowing before installation how his shock problem will be solved. Parker Hannifin Corporation 6 Des Plaines, IL USA Owen Sound, Ontario Canada www.comoso.com Catalog AU08-1022/NA Industrial Shock Absorbers Deceleration Principles: Self-Compensation Linear Decelerators Self-Compensating Shock Absorbers Figure A In cases where non-adjustability is beneficial but the features of an adjustable shock absorber are required, self-compen- sating shocks meet both needs. With a range of effective weight, a self-compensating shock absorber will provide acceptable deceleration under changing energy conditions. The orifice profile, designed by a computer that constantly Force arranges the size and location of each orifice while inputting changing effective weights, neutralizes the effect of changing fluid coefficients, weight, velocity, temperature and fluid compressibility. Figure A Stroke A linear decelerator by definition decelerates a moving weight at a linear or constant rate of deceleration. The adjustable Figure B shock absorber is able to provide linear deceleration when operated within its energy capacity and effective weight range by dialing in the required orifice area. The resulting force- stroke curve (Figure A) shows optimum (lowest) stopping force. Figure B Force Figure B shows the force-stroke of a self-compensating shock absorber stopping a weight at the low end of its effective weight range. Note how the reaction forces are no longer constant but are still acceptable. The curve is skewed slightly higher at the beginning of the stroke and dips lower at the end. Stroke Figure C Figure C Figure C is a force-stroke curve of the same self- compensating shock absorber in Figure B but at the high end of its effective weight range. The energy curve is now skewed upward at the end of stroke and still yields acceptable deceleration. Force Stroke Figure D Figure D Figure D is a family of force-stroke curves: a. Adjustable shock absorber properly tuned, or hydro d shock perfectly matched. b. Self-compensating shock absorber at the low end of its b c effective weight range. Force a c. Self-compensating shock absorber at the high end of its effective weight range. d. Adjustable closed down, or hydro shock not matched (dashpot effect). Stroke Parker Hannifin Corporation 7 Des Plaines, IL USA Owen Sound, Ontario Canada www.comoso.com Catalog AU08-1022/NA Industrial Shock Absorbers Horizontal Sizing Examples Linear Decelerators W = Moving Weight (lbs) Hp = Motor Power (horsepower) E = Kinetic Energy (in lbs) 1 V = Impact Velocity (ft/sec) Mu= Coefficient of Friction E = Propelling Force Energy (in lbs) 2 Fp= Known Propelling Force (lbs) C = Cycles per Hour (/hour) E = Energy per Cycle (in lbs) 3 B = Propelling Cylinder Bore (inches) s = Stroke Length of Shock Absorber (inches) E = Energy per hour (in lbs/hour) 4 R = Propelling Cylinder Rod (inches) F = Propelling Force at Shock Absorber (lbs) We= Effective Weight (lbs) P = Air Pressure (psi) HHHHH11111 WWWWWeeeeeiiiiiggggghhhhhttttt wwwwwiiiiittttthhhhh NNNNNooooo PPPPPrrrrrooooopppppeeeeelllllllllliiiiinnnnnggggg FFFFFooooorrrrrccccceeeee Examples: Crash Testers, Emergency Stops FORMULA EXAMPLE E = (0.186)•(W)(cid:127)(V2) W = 500 lbs E = (0.186)(cid:127)(500)(cid:127)(32) = 837 in lbs 1 1 E = (F)(cid:127)(s) V = 3 ft/sec E = (0)(cid:127)(1) = 0 in lbs 2 2 E = E + E Fp= 0 E = 900 + 0 = 837 in lbs 3 1 2 3 E = (E )(cid:127)(C) C = 500/hour E = (837)(cid:127)(500) = 418,500 in lbs/h 4 3 4 We = E / (0.186)(cid:127)(V2) We= 837 / (0.186)(cid:127)(32) = 500 lbs 3 H1 - Select from Model Rating Chart: MC 3325-3 or MA 3325 HHHHH22222 WWWWWeeeeeiiiiiggggghhhhhttttt wwwwwiiiiittttthhhhh PPPPPrrrrrooooopppppeeeeelllllllllliiiiinnnnnggggg FFFFFooooorrrrrccccceeeee Transfer Devices, Safety Doors, Cutting Shears F = Fp W = 14 lbs F = 30 =30 lbs E = (0.186)(cid:127)(W)(cid:127)(V2) V = 2.2 ft/sec E = (0.186)(cid:127)(14)(cid:127)(2.22) =12.6 in lbs 1 1 E = (F)(cid:127)(s) Fp= 30 lbs E = (30)(cid:127)(0.4) =12 in lbs 2 2 E = E + E C = 100/hour E = 12.6 + 12 =24.6 in lbs 3 1 2 3 E = (E )(cid:127)(C) s = 0.4 inches E = (24.6)(cid:127)(100) =2,460 in lbs/h 4 3 4 We = E / (0.186)(cid:127)(V2) We= 24.6 / (0.186)(cid:127)(2.22) =27.3 lbs 3 H2 - Select from Model Rating Chart: MC 75-3 HHHHH33333 WWWWWeeeeeiiiiiggggghhhhhttttt wwwwwiiiiittttthhhhh PPPPPrrrrrooooopppppeeeeelllllllllliiiiinnnnnggggg CCCCCyyyyyllllliiiiinnnnndddddeeeeerrrrr Pick-and Place Units, Linear Slides, Robotics F = 0.785(cid:127)(B2-R2)(cid:127)(P) W = 120 lbs F = 0.785(cid:127)(1.52-02)(cid:127)60 = 106 lbs E = (0.186)(cid:127)(W)(cid:127)(V2) V = 2 ft/sec E = (0.186)(cid:127)(120)(cid:127)(22) = 89.3 in lbs 1 1 E = (F)(cid:127)(s) B = 1.5 inches E = (106)(cid:127)(0.75) = 79.5 in lbs 2 2 E = E + E R = 0 inches E = 89.3 + 79.5 = 168.8 in lbs 3 1 2 3 E = (E )(cid:127)(C) P = 60 psi E = (168.8)(cid:127)(60) = 10,128 in lbs/h 4 3 4 We = E / (0.186)(cid:127)(V2) C = 60/hour We= 168.8 / (0.186)(cid:127)(22) = 226.9 lbs 3 Note: R = 0 when using a rodless cylinder s = 0.75 inches or a cylinder working in extension. H3 - Select from Model Rating Chart: MA 225 or SC 300-4 HHHHH44444 WWWWWeeeeeiiiiiggggghhhhhttttt wwwwwiiiiittttthhhhh MMMMMoooootttttooooorrrrr DDDDDrrrrriiiiivvvvveeeee Lift Trucks, Stacker Units, Overhead Cranes F = (550)(cid:127)(ST)(cid:127)(Hp) / V W = 2,100 lbs F = (550)(cid:127)(2.5)(cid:127)(2) / 1 = 2,750 lbs E = (0.186)(cid:127)(W)(cid:127)(V2) V = 1 ft/sec E = (0.186)(cid:127)(2,100)(cid:127)(12) = 390.6 in lbs 1 1 E = (F)(cid:127)(s) Hp= 2 hp E = (2,750)(cid:127)(2) = 5,500 in lbs 2 2 E = E + E ST= 2.5 E = 390.6 + 5,500 = 5,890.6 in lbs 3 1 2 3 E = (E )(cid:127)(C) C = 20/hour E = (5,890.6)(cid:127)(20) = 117,812 in lbs/h 4 3 4 We = E / (0.186)(cid:127)(V2) s = 2 inches We= 5,890.6 / (0.186)(cid:127)(12)= 31,670 lbs 3 H4 - Select from Model Rating Chart: ML 6450 or MC 6450-4 HHHHH55555 WWWWWeeeeeiiiiiggggghhhhhttttt ooooonnnnn PPPPPooooowwwwweeeeerrrrr RRRRRooooolllllllllleeeeerrrrrsssss/////CCCCCooooonnnnnvvvvveeeeeyyyyyooooorrrrr Pallet Line, Friction Conveyor Belt, Steel Tube Transfer F = (W)(cid:127)(Mu) W = 250 lbs F = (250)(cid:127)(0.2) = 50 lbs E = (0.186)(cid:127)(W)(cid:127)(V2) V = 2.5 ft/sec E = (0.186)(cid:127)(250)(cid:127)(2.52) = 290.6 in lbs 1 1 E = (F)(cid:127)(s) Mu= 0.2 E = (50)(cid:127)(1) = 50 in lbs 2 2 E = E + E C = 180/hour E = 290.6 + 50 = 340.6 in lbs 3 1 2 3 E = (E )(cid:127)(C) s = 1 inch E = (340.6)(cid:127)(180) = 61,308 in lbs/h 4 3 4 We = E / (0.186)(cid:127)(V2) We= 340.6 / (0.186)(cid:127)(2.52)= 293 lbs 3 H5- Select from Model Rating Chart: MA 600 or SC 650-3 Parker Hannifin Corporation 8 Des Plaines, IL USA Owen Sound, Ontario Canada www.comoso.com