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Hydraulic Application

Specifications

Hydraulic Application

For applications where an engine mounted AuraGen is not available and the vehicle has a available Power Take Off (PTO) port on the transmission, AuraGen has a hydraulic Mounting kit available. All of the necessary components are included in the basic mounting kit to be able to (1) couple the AuraGen generator to a hydraulic motor (2) and attach the generator/hydraulic motor to the vehicle chassis. The following pages outline the information necessary to properly size a hydraulic motor and pump systems that are available from various suppliers (Eaton, Vickers, etc). Background The AuraGen generator produces electrical power from mechanical energy (through rotation of a conductive rotor through a magnetic field), any drive method that will spin the rotor at the appropriate speed and required torque may be employed. Such methods include PTO and hydraulic drives. To maintain the necessary rotational speed of the generator, the vehicle engine may need to incorporate a Throttle Control Unit (TCU). The TCU is integrated with the vehicle's throttle using a mechanical cable attachment or electronic interface to the OEM throttle. Some vehicles manufacturers incorporate a high idle switch or a solenoid that increases the engine RPM to allow PTO port to spin at higher speeds. The TCU may be omitted if the drive method selected permits the generator rotor to spin at the minimum rpm necessary to provide 5000 watts of power. Figure 1 highlights a example PTO with a hydraulic motor drive configuration for a AuraGen generator.

Figure 1. Example of a PTO/Hydraulic Drive Application Rotational Speed Requirement In order to produce 5000 watts of power, the generator rotor must turn at a minimum speed of 2,600 RPM. In addition to the stated RPM requirements, the mechanical structure of the generator dictates that rotational speed at any time not exceed 12,000 RPM nor operate (producing power) for extended periods of time above 10,000 RPM. For optimal performance, it is recommended that the PTO or hydraulic drive system be adjusted to drive the generator rotor at a constant speed of at least 2,800 RPM. This will ensure proper cooling of the generator at higher loads and prevent exceeding the performance limits of typical hydraulic motors.

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Hydraulic Application

Torque Requirement

Required Torque to Drive The AuraGen @ 5000 W Output (ft-lbs)

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While the G5000 system is rated at 5000 watts, inefficiencies in the system require a higher input power. The necessary torque to drive the generator rotor at 5000 watts can be calculated using the following formula: Torque (ft-lbs.) = 57,600 / Generator RPM For example, at 3000 RPM the torque required to drive the AuraGen Generator to produce 5000 watts is 19.2 ft-lbs. See Figure 2 for a curve showing the relationship between Generator RPM vs. required torque to drive the AuraGen Generator. Note that the torque formula and curve represents the torque required to drive the AuraGen at an output level of 5000 watts. For power requirements other than 5000 watts this formula does not apply (e.g. lower power demands will require less torque.) The torque value is expressed in ft.-lbs. Ventilation Requirement The Generator requires an adequate airflow to maintain proper operation. Installations should be designed so that the front and rear circular faces of the Generator are not blocked. For installations that incorporate a stone/splash guard, care must be taken to provide adequate airflow to cool the Generator. Generator Drive Pulley The standard Generator Drive Pulley is approximately 4.1" in diameter, 1" thick, and has a Micro-Vee profile to accommodate a 6-groove serpentine belt. It is coupled to the generator shaft using a woodruff key, a flat washer and a bolt. The pulley also includes three jack screw holes (0.190" -32 UNF-2B threads) for removing the pulley from the generator. The Generator Drive Pulley is included in the Hydraulic Mounting Kit to provide the ECU/speed sensor with the required input profiles. A modified coupler attaches to the generator pulley to the hydraulic motor output shaft (motor has a 1/4" keyway and set screws). Note: The generator pulley is part of the control system and should not be substituted with a different pulley.

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Generator RPM

Figure 2. Required AuraGen Torque vs. RPM Electronic Control Unit The Electronic Control Unit (ECU) houses the electronics that controls the generator and conditions the output power. The G5000 ECU is approximately 19.3" long x 13.5" wide x 8.6" tall and should be mounted in an area allowing adequate ambient air flow. Control Panel The Control Panel allows the user to turn the system on or off, as well as provide LED indicators that flash in accordance with defined fault sequences. The Control Panel is approximately 4.0" long x 3.4" wide x 1.5" tall and is typically mounted near or on the vehicle dashboard.

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Hydraulic Application

M050-316 - Hydraulic Mounting Kit ­ not including motor

The M050-316 mounting bracket kit includes the following items: · · · · · Generator to Vehicle Mounting Bracket Generator Pulley with a woodruff key, dowel pins and bolt. Modified coupler with fasteners to attach to the generator pulley and hydraulic motor. Necessary hardware to mount the generator and hydraulic motor to the bracket. AuraGen Control Panel

Hydraulic Mounting Kit including Hydraulic Motor

AuraGen can supply the Hydraulic Mounting Bracket Kit (M050-316) with a hydraulic motor (M050-318). In addition, for a nominal charge, this motor and a AuraGen generator can be assembled and aligned onto the mounting bracket prior to shipment. Note that because of the size and weight of the assembly, it will need to be palletized and shipped via customer's preferred vendor. The Hydraulic Mount System includes the following items: Description · · · Generator to Vehicle Mounting Bracket Eaton Model 74118-DAP-01 Hydraulic Motor (or equivalent) Assembly and alignment of the generator and motor to the bracket. AuraGen P/N M050-316 M050-318 Optional

The mounting bracket has a bolt pattern feature for a two bolt SAE "A" type hydraulic motor. A suggested motor is discussed on the following pages.

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Hydraulic Application

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Hydraulic Application

Sizing the Hydraulic Motor

The equation below shows the relationship between the required hydraulic fluid flow rate at a rated pressure and speed (RPM) level to achieve 5000 watts of power from the AuraGen system. For systems that will be operating below 5000 watts, a lower flow rate, motor speed or motor size can be specified. Note that system losses due to the hydraulic plumbing, valves and pump are not included in this estimate. Definitions: QM = Minimum Flow rate (gallons-per-minute, GPM) P = Pressure difference/drop across the motor (pounds per square inch, PSI) k = Constant (1714) = Hydraulic motor efficiency at desired generator speed (RPM) HP = Horsepower to operate AuraGen Flow and HP Requirement Calculations:

QM = k x HP ÷ (P x )

For 5 kW Steady­State Operation: QSS = 1714 x 10.5 HP ÷ (2200 PSI x 0.76) = 10.8 gal/min @ 2800 RPM For a 8kW Surge: QP = 1714 x 16.6 HP ÷ (2600 PSI x 0.76) = 14.4 gal/min @ 2800 RPM HP required from motor for 5kW operation: HPSS = QM(5kW) x P ÷ k = 10.8 GPM x 2200 PSI ÷ 1714 = 13.8 HP HP required from motor for 8kW surge: HPP = QM(8kW) x P ÷ k = 14.4 GPM x 2600 PSI ÷ 1714 = 21.8 HP Volumetric Displacement Peak = QM ÷ Motor RPM = 14.4 GPM ÷ 2800 RPM = 0.005143 gal/rev; 0.005143 gal/rev x 231 in /gal = 1.19 in /rev

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Suggested Hydraulic Motor:

Eaton Model Number: 74118-DAP-01 (Medium Duty Piston Type Motor) This motor is rated for a maximum output of 31.1 hp at 3600 RPM and 20.8 GPM and has a displacement of 1.24 in3/rev (20.3 cm3/rev). To sustain a 5 kW load capacity the suggested motor speed, pressure and flow-rate settings are as follows. The motor pressure difference should be approximately 2,200 PSI and the speed set to approximately 2,800 RPM. At these conditions, the necessary flow rate will be roughly 10.8 gallonsper-minute (see equation above). The horsepower required from the motor is 13.8 HP (see equation above). Suggestion: By comparing the output power versus the shaft RPM graph from the hydraulic motor manufacturer, you can verify that the motor will achieve the power output at the required generator RPM.

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Hydraulic Application

Sizing the Hydraulic Pump

The equation below shows the required hydraulic fluid flow rate that needs to be supplied from a hydraulic pump. These numbers represent the required flow rate for the suggested Eaton piston type motor (Part #: 74118-DAP-01) mentioned on the previous page. The calculations also assume a pump efficiency of 80% and a plumbing/regulator loss of 20%. Both the pump and plumbing efficiencies can be different depending upon the equipment used. Below is an example calculation for a system that operates at 5,000 Watts, steady state, and can handle power surges up to 8,000 Watts. Definitions: QSS = Required output flow of pump for operation at 5kW (gallons per minute; GPM) P = Hydraulic Pump Pressure Level (pounds per square inch; PSI) QP = Required output of pump to handle a 8kW surge (gallons per minute; GPM) p = Hydraulic Pump Efficiency HPINPUT = Horsepower to drive Hydraulic Pump k = Constant (1714) LLINE = Hydraulic Plumbing/Line loss Required Pump Flow (Calculations): Assumptions: Assuming a pump efficiency of 80% and a line loss of 20%. Horsepower to drive Hydraulic Motor = QM x PM

QPUMP = QM ÷ (1 - LLINE)

QSS= QM(5kW) ÷ (1 ­ line loss) = 10.8 GPM ÷ (1 ­ 0.2) = 13.5 GPM QP = QM(Peak) ÷ (1 ­ line loss) = 14.4 GPM ÷ (1 ­ 0.2) = 18.0 GPM HP required to drive the Pump:

HPINPUT = Q x P ÷ (P x k)

HPSS = QSS x P ÷ (p x k) = 13.5 GPM x 3000 ÷ (0.8 x 1714) = 29.5 HP HPP = QP x P ÷ (p x k) = 18.0 GPM x 3000 ÷ (0.8 x 1714) = 39.4 HP

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