Single displacement SAI GM motor
Dual displacement variable SAI BD motor
SAI hydraulic GM motor GM05 GM1 GM2 GM3 GM4 GM5 GM6 GM7 GM9
GM Series Motor are a result of the many years of experience gained with the preceding M, L and P Series Motor, and incorporate a number of design variations with respect to these series to increase the strength of the motor casings and the load capacity of the internal dynamic components.
The result is a series of motor with high continuous power ratings, reduced internal loads and high mechanical and volumetric efficiency that contribute in reducing the amount of heat and therefore also the negative effects associated with it.
All the motor are rated at a nominal continuous pressure rating of 3,650 psi. The continuous and average operating pressure, however, should be chosen in function of the required bearing lifetime. The peak operating pressures are given in the relative displacement tables. The motor may work at peak pressures for periods not exceeding 1% per minute, no more than 10 times per hour.
The motor are capable of operating with high back-pressures with high efficiency, e.g. for series circuit applications.
The allowable pressures vary in function piston diameter and other factors. If the motor are required for an application with back pressure contact the technical department for further details.
Typical allowable back-pressure Continuous. 3,000 psi (Port A) and 2,200 psi (Port A) Peak 5,000 psi (Port A) and 5,000 psi (Port A)
Continuous case pressure: 15 psi, and Peak case pressure: 75 psi
The case pressure is independent of the return line pressure. For higher pressures (up to 350 psi) contact the technical department.
To obtain the theoretical output torque of a motor, multiply the specific torque (lb.ft/psi) given in the displacement tables by the pressure (psi). The graph below shows the output torque variation as the shaft rotates through 360°.
LOW SPEED OPERATION
The motor are capable of operating at low speeds with a high degree of speed stability. The minimum stable speed depends on the displacement of the motor. In general the motor remain sensitive to flows of 6 in3/min + motor leakage rate. Best results are obtained with 75-150 psi backpressure and after the circuit has been completely purged of air by running it at 2/3 max speed for 5-10 mins. The output torque does not fall off at very low speeds or at standstill.
The motor operate at lowest noise levels with a back-pressure of 75-150 psi, such as in closed circuits. Pressure lines and motor support structures can be efficient noise propagators or amplifiers. Pressure lines should preferably be made up of straight rigid lengths, flexible corners, firmly fixed to rigid supports at irregular intervals away from sheet paneling. Motor must be rigidly fixed to solid supports.
The design of the motor ensures they are not damaged if subjected to cavitations, even for prolonged periods of time.
The motor will rotate normally even with empty cylinders (i.e. no oil – air, or vacuum), which is useful for disconnecting the motor from the hydraulic circuit
GM-series motor does not contain bronze components. However, high speed distributors (including the standard D40 and D90 distributors) do contain bronze components. If the hydraulic fluid used is not compatible with bronze, select an optional low speed (LS) distributor (no bronze components) or contact our technical department.
Technical Data of GAI GM Motor
Table of values (theoretical values, without efficiency and tolerances; values rounded)
|GM05 motor||GM05 90||GM05 110||GM05 130||GM05 150||GM05 170|
|Rated torque Nm||343||458||513||600||660|
|Max. speed rpm||1000||900||900||900||800|
|Max. power KW(HP)||20(27)||20(27)||20(27)||20(27)||20(27)|
|GM1 motor||GM1 100||GM1 150||GM1 175||GM1 200||GM1 250||GM1 300||GM1 320||GM1 350|
|Rated torque Nm||385||600||670||785||950||1130||1225||1060|
|Max. speed rpm||1000||1000||900||800||700||650||600||550|
|Max. power KW(HP)||48(65)||48(65)||48(65)||48(65)||48(65)||48(65)||48(65)||48(65)|
|GM2 motor||GM2 200||GM2 250||GM2 300||GM2 350||GM2 420||GM2 500||GM2 600||GM2 630|
|Rated torque Nm||750||980||1188||1355||1658||1923||2208||2433|
|Max. speed rpm||800||800||750||750||750||700||700||650|
|Max. power KW(HP)||59(79)||59(79)||59(79)||59(79)||59(79)||59(79)||59(79)||59(79)|
|GM3 motor||GM3 500||GM3 600||GM3 700||GM3 800||GM3 900||GM3 1000|
|Rated torque Nm||1895||2320||2700||3100||3400||3850|
|Max. speed rpm||600||575||500||500||400||350|
|Max. power KW(HP)||80(107)||80(107)||80(107)||80(107)||80(107)||80(107)|
|GM4 motor||GM4 600||GM4 800||GM4 900||GM4 1000||GM4 1100||GM4 1300|
|Rated torque Nm||2403||3100||3525||4000||4350||5125|
|Max. speed rpm||550||550||450||400||400||350|
|Max. power KW(HP)||100(134)||100(134)||100(134)||100(134)||100(134)||100(134)|
|GM5 motor||GM5 1000||GM5 1200||GM5 1300||GM5 1450||GM5 1600||GM5 1800||GM5 2000|
|Rated torque Nm||4050||4625||5225||5700||6350||7075||7825|
|Max. speed rpm||450||400||400||350||300||300||250|
|Max. power KW(HP)||120(160)||120(160)||120(160)||120(160)||120(160)||120(160)||120(160)|
|GM6 motor||GM6 1700||GM6 2100||GM6 2500||GM6 3000|
|Rated torque Nm||6600||8300||9800||11875|
|Max. speed rpm||400||350||300||250|
|Max. power KW(HP)||170(228)||170(228)||170(228)||170(228)|
Dual Displacement variable high torque hydraulic SAI BD motor
SAI BD motor series BD1 BD2 BD3 BD5 BD6
Technical Data of GAI BD Motor
Table of values (theoretical values, without efficiency and tolerances; values rounded)
|M a x||M in||M a x||M in||M a x||M in||M a x||M in||M a x||M in||M a x||M in||M a x|
|[c c /rev] 100||
|BD2||[c c /rev] 500||250||500||175||500||125||350||175||350||125||350||90||250|
|BD3||[c c /rev] 550||130||750||170||900||220||–||–||–||–||–||–||–|
|BD5||[c c /rev] 1000||250||1500||400||1900||500||–||–||–||–||–||–||–|
|BD6||[c c /rev] 1700||420||2100||530||2100||700||2100||1100||2500||630||3000||760||–|
Displacements Available: 6.1 to 112.7 cu.-in./rev. (full displacement)
Max-Min Displacement Ratio from 1.2 to 6:1
Maximum Speed 3500 rpm
Peak Power: 322 hp
94% Starting and running torque
99% Volumetric efficiency
Sai BD Series Dual Displacement Motor is also based off the GM Series but incorporates the innovative central bearing.
The shift from one displacement to the other is achieved by pilot pressure acting on a crank shaft eccentric. This ensures a smooth transition when shifting from one speed to the other.
BD Series also tolerate freewheeling in full cavitations as with other models. If run as a pump they can also reach full speed in low displacement.
The motors are capable of working at low speeds with a high degree of speed stability.
Output torque remains constant and does not fall away at very low speeds, on start up or in stall conditions. BD2 offers 100% to 50 % speed change ratio while BD1 offers 100 % to 25%.
The BD series of products consists of items that are available in sizes from 1 to 6, being characterized by slide bearings and an extremely low friction coefficient. The very high starting torque efficiency and the mechanical efficiencies that are higher than average are other important features worth mentioning, and are applicable in both low and high displacement models. The motors are capable of working at low speeds with a high degree of speed stability, with the minimum stable speed depending on the motor displacement.
The output torque remains very constant and does not fall away at very low speeds, under start or stall conditions. The change of the motor displacement is achieved by changing the crankshaft stroke, at a pressure between 20 and 30bar. The change from high to low displacement or from low to high can take place dynamically.
GENERAL CHARACTERISTICS & FEATURES
Five cylinder crankshaft design radial pistion hydraulic motor. The BD Series motor utilizes many of the proven components from the GM Series motors, well known for their high performance and reliability. The innovative design of the new sliding central bearing arrangement, made possible by the latest materials and manufacturing techniques increases the range of possible options in SAI hydraulic motors. These include the possibility to change displacement, fit taper roller bearings for axial load capability, have a hollow through shaft option, and fit a counterbalance weight to smooth out high speed vibration. Its also possible to accept higher radial loading of the motor shaft due to a larger cross section giving extra strength.
CHANGE OF DISPLACEMENT
Change of motor displacement in the BD Series is achieved by changing the stroke of the crankshaft. This is achieved by a low pressure external pilot signal and changes from high to low displacement and vice versa can take place both dynamically, with a smooth speed variation, and statically.
The BD Series motors can be freewheeled in full cavitations.
DESIGN & OPERATION
The sliding bearing has an extremely low coefficient of friction and as a consequence gives very high starting torque efficiency, and continues to achieve higher then average mechanical efficiencies both in high and low displacement modes. At present, the maximum running speed is restricted to the flow which can pass through distributor which is fitted to this series of motors.
STARTING & LOW SPEED TORQUE
The motors are capable of working at low speeds with a high degree of speed stability. The minimum stable speed depends on the displacement of the motor. Output torque remains very constant and does not fall away at very low speeds or under stall or start conditions.