Aura Systems, Inc., (310) 643-5300. www.aurasystems.com

PTO AND HYDRAULIC DRIVE

Section 4

PTO AND HYDRAULIC APPLICATION GUIDE

POWER TAKEOFF

AURAGEN CATALOG, SECTION 4

HYDRAULIC DRIVEN

Page 4-1

FS-100, JANUARY, 2005

Aura Systems, Inc., (310) 643-5300. www.aurasystems.com

PTO DRIVE POWER TAKE OFF APPLICATION (PTO SHAFT DRIVEN) AuraGen has a mounting kit available for applications where a vehicle is equipped with a Power Take Off (PTO) port. Aura provides a complete basic mounting kit consisting of all necessary components for attaching the AuraGen generator to the vehicle chassis in a position where a customer supplied PTO drive shaft can be connected. The following pages outline the information necessary regarding the contents and design features of the AuraGen PTO kit. 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 an Idle Control Unit (ICU). Some vehicle manufacturers incorporate a high idle switch or a solenoid that increases the engine RPM to allow the PTO port to spin at higher speeds. The idle control is not required if the drive method selected permits the generator rotor to spin within the minimum and maximum RPM range and with adequate torque to provide continuous 5,000 or 8,000 watts (G8500 systems) of power. Fig. 1 shows a general arrangement of components in a typical PTO system driving an AuraGen generator. Several mounting kit variations are offered by Aura to satisfy the customer’s vehicle PTO configuration for transmission port location and direction of rotation.

Fig. 1: General Arrangement of an AuraGen PTO Drive Application

AURAGEN CATALOG, SECTION 4

Page 4-2

FS-100, JANUARY, 2005

Aura Systems, Inc., (310) 643-5300. www.aurasystems.com

PTO DRIVE Rotational Speed Requirements For G5000 systems, in order to produce 5000 watts of power (continuous) the generator rotor must turn at a minimum speed of 2,600 RPM. (For optimal performance, it is recommended that the vehicle PTO system be adjusted to drive the generator rotor at a constant speed of at least 3,000 RPM). For G8500 systems, in order to produce 8,000 watts (continuous) the rotor should turn at a minimum speed of 3,000 RPM. (For optimal performance, it is recommended that the vehicle PTO system be adjusted to drive the generator rotor at a constant speed of at least 3,400 RPM.) Operating at the optimal performance will ensure proper cooling of the generator at higher loads. In addition to the stated RPM requirements, the generator’s rotational speed should not exceed 12,000 RPM at any time. See Fig. 2.

AuraGen Model

Minimum Speed

Recommended Speed

Maximum Speed

G5000

2,600 RPM

3,000 RPM

12,000 RPM

G8500

3,000 RPM

3,400 RPM

12,000 RPM

Fig. 2: AuraGen Rotational Speed Requirements

PTO Requirements Constant mesh, “hot-shift”, and manually engaged PTO systems are all compatible with the AuraGen product line. PTO’s manufactured by Muncie Power Products, Inc. or by Chelsea Systems, a division of the Dana Corp., is frequently used; however the use of the AuraGen is not limited to these firms. The AuraGen mounting kit is designed to mount on the vehicle chassis at approximately the four or nine o’clock position (as viewed from the rear of vehicle) of the transmission. This orientation provides the optimum space and proximity to the C-channel frame members on the chassis for mounting the Generator in a location that will provide proper drive shaft alignment. Although this position is desired, it is not mandatory. Other PTO to transmission relationships can be accommodated. When determining the necessary drive components, the PTO step-up or step-down ratio needs to be considered. A PTO with a step-up ratio in combination with pulleys used between the PTO shaft and the generator can yield an acceptable AuraGen rotor speed that will produce full power at or near engine idle speed. Care should be exercised when reviewing the PTO ratio to insure that the maximum rated Generator speed at engine redline is not exceeded. The recommended PTO ratio is 1.25:1 or 1.33:1 in combination with the AuraGen PTO mounting kit pulley ratio of 3.2:1. Verify that the engine RPM/PTO ratio will not cause the AuraGen rotor speed, under any conditions, to exceed 12,000 RPM. The idle speed of the engine may need to be increased to satisfy the mandatory levels indicated below. For a G5000: Min Necessary Engine RPM = 938 / (PTO Ratio) For a G8500: Min Necessary Engine RPM = 1,063 / (PTO Ratio)

AURAGEN CATALOG, SECTION 4

Page 4-3

FS-100, JANUARY, 2005

Aura Systems, Inc., (310) 643-5300. www.aurasystems.com

PTO DRIVE Torque Requirement See Fig. 3 showing the relationship between Generator RPM vs. the required torque to drive the AuraGen generator. For G5000 systems, the necessary torque to drive the generator rotor at 5,000 watts can be approximated by using the following formula: Torque (ft-lbs.) =

53,500 Generator RPM

For G8500 systems, the necessary torque to drive the generator rotor at 8,000 watts can be approximated by using the following formula: Torque (ft-lbs.) =

75,800 Generator RPM

For example, at 3,000 RPM the torque required to drive the AuraGen (generator) to produce 5,000 watts is 17.8 ft-lbs. Note that the torque formula and curve represents the torque required to drive the AuraGen at full rated load. For power requirements other than the full rated load this formula does not apply (e.g. lower power demands will require less torque.) The torque value is expressed in ft.-lbs. 36.00

31.00

G8500

Torque (Ft-Lbs)

26.00

21.00 G5000 16.00

11.00

6.00 1600

2600

3600

4600

5600

6600

7600

8600

AuraGen Speed (RPM)

Fig. 3: Required AuraGen Torque vs. RPM

Ventilation Requirement The Generator requires an adequate airflow to maintain proper operation. Installations should be designed so that the PTO enclosure vents are not blocked.

AURAGEN CATALOG, SECTION 4

Page 4-4

FS-100, JANUARY, 2005

Aura Systems, Inc., (310) 643-5300. www.aurasystems.com

PTO DRIVE Auxiliary Power Shaft Mount Assembly Interface The auxiliary power shaft from the vehicle PTO to the AuraGen mounting kit is not provided by Aura Systems, Inc. Determination of the type and size of the auxiliary power shaft is the responsibility of the engineering/installation facility. The following PTO auxiliary power shaft interface information is provided to assist in determining which auxiliary power shaft and configuration is best for the individual vehicle being developed. Details of the auxiliary power shaft mount interfaces are provided in Fig. 4.

Fig. 4: AuraGen Auxiliary Power Shaft Mount

Auxiliary Power Shaft - Universal Joint Operating Angle The following paraphrase was taken from the Spicer (Dana) Auxiliary Power Driveline Components Manual. “An auxiliary power shaft transmits torque from the power source to the driven accessory. The shaft must be capable of transmitting the maximum torque and RPM required of the accessory, plus any shock loads which may develop.” “The shaft operates through constantly changing relative angles between the power source and the driven accessory; therefore, the length of the shaft must be capable of changing while transmitting torque. This length change, commonly called “slip movement”, is caused by movement of the power train due to torque reactions and chassis deflections.” “Joint operating angles are very important in an auxiliary power joint application. In many cases, the longevity of a joint is dependent on the operating angles.” The recommended universal joint operating angle for the AuraGen PTO auxiliary power shaft is within five (5) degrees from parallel to the PTO centerline. See Fig. 5.

Fig. 5: Auxiliary Power Shaft Universal Joint Operating Angle

AURAGEN CATALOG, SECTION 4

Page 4-5

FS-100, JANUARY, 2005

Aura Systems, Inc., (310) 643-5300. www.aurasystems.com

PTO DRIVE Auxiliary Power Shaft Example Aura chose the following auxiliary power shaft for development of the PTO application. Mfg: Dana Supplier: Driveline Service of Fresno, Inc. Style: 1310 Series PTO Assembly Type Yoke: Round Bore, PN 2-28-357 Yoke Key: 1/4" Spline Set: 1/1/4" x 2" Slip & Stub Universal Joints PN: 5-153X

Yoke Bore: 1 1/4" Yoke Retention: Set screw(s)

Generator and PTO Drive Pulleys The PTO Generator Drive Pulley is approximately 3.0” in. diameter and incorporates a sprocket to provide the ECU/speed sensor with the required input. It is coupled to the generator shaft using a woodruff key, a flat washer and a bolt. The pulley also includes three jackscrew holes (0.190” -32 UNF-2B threads) for removing the pulley from the generator. The PTO Drive Pulley is approximately 9.0” in diameter, aligns to the Generator Drive Pulley, and is connected to the PTO drive shaft through a Drive Shaft Mount Assembly. Each drive pulley has a Micro-Vee profile to accommodate a 12-groove serpentine belt (Gates PN K120400). Note: The generator pulley is part of the control system and should not be substituted with a different pulley. See Fig. 6. Also see Fig. 7 for PTO drive location, direction of rotation orientation, and supplemental kit listing that supports each configuration.

AURAGEN CATALOG, SECTION 4

Page 4-6

FS-100, JANUARY, 2005

Aura Systems, Inc., (310) 643-5300. www.aurasystems.com

PTO DRIVE M050-319 – Power Take Off Mounting Kit •

The M050-319 mounting bracket kit includes the following items: See Fig. 6.

•

Generator to Vehicle Mounting Bracket

•

Generator Pulley with a woodruff key, dowel pins and bolt

•

Auxiliary Power Shaft Mount Assembly to attach the customer supplied PTO shaft and AuraGen Drive Pulley

•

Necessary hardware to mount the generator and PTO shaft

•

AuraGen Control Panel

•

Enclosure system to protect the AuraGen and drive components from debris and road splash. Separate enclosures are available for driver or passenger side mounting.

•

A serpentine belt tensioner for either clockwise or counterclockwise PTO drive rotation.

Note: Auxiliary power shafts and PTO’s are customer supplied.

Fig. 6: Typical PTO Mounting Kit (Driver Side Shown)

AURAGEN CATALOG, SECTION 4

Page 4-7

FS-100, JANUARY, 2005

Aura Systems, Inc., (310) 643-5300. www.aurasystems.com

PTO DRIVE

Kit PN

Description

Kit PN

Description

M050-319 PTO Base Kit

M050-319 PTO Base Kit

M050-382 Supplemental Tensioner Kit

M050-381 Supplemental Tensioner Kit

M050-377 Supplemental Enclosure Kit

M050-377 Supplemental Enclosure Kit

Kit PN

Description

Kit PN

Description

M050-319 PTO Base Kit

M050-319 PTO Base Kit

M050-382 Supplemental Tensioner Kit

M050-381 Supplemental Tensioner Kit

M050-378 Supplemental Enclosure Kit

M050-378 Supplemental Enclosure Kit

Fig. 7: Power Takeoff Kit Configurations AURAGEN CATALOG, SECTION 4

Page 4-8

FS-100, JANUARY, 2005

Aura Systems, Inc., (310) 643-5300. www.aurasystems.com

HYDRAULIC DRIVE Hydraulic Drive Application (PTO Driven Pump) For applications where an AuraGen engine mounting kit is not available and the vehicle has an adequate auxiliary hydraulic system available, 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 and (2) 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). Aura Systems recommends that a hydraulic pump of sufficient volume and pressure be coupled to the Power Take Off (PTO) port on the vehicle’s transmission. 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 shaft and hydraulic drives. To maintain the necessary rotational speed of the generator, the vehicle engine may need to incorporate an Idle Control Unit (ICU). Some vehicles manufacturers incorporate a high idle switch or a solenoid that increases the engine RPM to allow the PTO port to spin at higher speeds. The idle control is not required if the drive method selected permits the generator rotor to spin at the minimum recommended RPM and adequate torque necessary to provide continuous 5,000 or 8,000 watts (G8500 systems) of power. Fig. 8 shows a typical hydraulic pump mounted to a PTO with a hydraulic motor drive configuration for an AuraGen generator.

Fig. 8: Example of a PTO/Hydraulic Drive Application

AURAGEN® CATALOG, SECTION 4

PAGE 4-9

FS-100, SEPTEMBER, 2004

Aura Systems, Inc., (310) 643-5300. www.aurasystems.com

HYDRAULIC DRIVE Rotational Speed Requirement In order to produce 5000 watts of power (continuous), the generator rotor must turn at a minimum speed of 2,600 RPM. For 8,000 watt systems (continuous) the rotor should turn at a minimum speed of 3,000 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 3,000 RPM for 5,000 watt systems and 3,400 RPM for 8,000 watt systems. This will ensure proper cooling of the generator at higher loads and prevent exceeding the performance limits of typical hydraulic motors. Torque Requirement While the AuraGen system is rated up to 8,000 watts (continuous), inefficiencies in the system require a higher input power. For G5000 systems, the necessary torque to drive the generator rotor at 5,000 watts can be approximated by using the following formula: Torque (ft-lbs.) = 53,500 / Generator RPM For G8500 systems, the necessary torque to drive the generator rotor at 8,000 watts can be approximated by using the following formula: Torque (ft-lbs.) = 75,800 / Generator RPM For example, at 3,000 RPM the torque required to drive the AuraGen (generator) to produce 5,000 watts is 17.8 ft-lbs. See Fig. 9 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 5,000 watts. For power requirements other than 5,000 watts this formula does not apply (e.g. lower power demands will require less torque.) The torque value is expressed in ft.-lbs.

36.00

31.00

G8500

Torque (Ft-Lbs)

26.00

21.00

G5000 16.00

11.00

6.00 1600

2600

3600

4600

5600

6600

7600

8600

AuraGen Speed (RPM)

Fig. 9: Required AuraGen Torque vs. RPM

AURAGEN CATALOG, SECTION 4

Page 4-10

FS-100, JANUARY, 2005

Aura Systems, Inc., (310) 643-5300. www.aurasystems.com

HYDRAULIC DRIVE Ventilation Requirement The AuraGen (generator) requires adequate air circulation 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 4.0” 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 jackscrew 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. Electronic Control Unit The Electronic Control Unit (ECU) houses the electronics that controls the generator and conditions the output power. See Section 1 of this catalog for dimensional envelope for all series of ECU’s. Each must be mounted in an area allowing adequate ambient air circulation to maintain an ambient air temperature of 120 °F. If it is mounted underneath the vehicle, it needs protection from water splash and submersion. Control Panel The control panel allows the user to turn the system on or off, and includes LED indicators that flash in accordance with defined fault conditions. The Control Panel is typically mounted near or on the vehicle dashboard. 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 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. 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 AuraGen generator can be assembled and aligned onto the mounting bracket prior to shipment (M050-317). Note that because of the size and weight of the assembly, it will need to be palletized and shipped via customer’s preferred mode of transportation. See Fig. 10. Hydraulic Mounting Kit Envelope See Fig. 11.

AURAGEN CATALOG, SECTION 4

Page 4-11

FS-100, JANUARY, 2005

Aura Systems, Inc., (310) 643-5300. www.aurasystems.com

HYDRAULIC DRIVE The Hydraulic Mount System includes the following items: Description • • •

AuraGen P/N

Generator to Vehicle Mounting Bracket Eaton Model 74118-DAP-01 Hydraulic Motor (or equivalent) Assembly and alignment of the generator with the hydraulic motor onto the bracket.

M050-316 M050-318 M050-317

Fig. 10: Hydraulic Mounting Kit Assembly

AURAGEN CATALOG, SECTION 4

Page 4-12

FS-100, JANUARY, 2005

Aura Systems, Inc., (310) 643-5300. www.aurasystems.com

HYDRAULIC DRIVE

Fig. 11: Assembled Hydraulic Mounting Kit Envelope

AURAGEN CATALOG, SECTION 4

Page 4-13

FS-100, JANUARY, 2005

Aura Systems, Inc., (310) 643-5300. www.aurasystems.com

HYDRAULIC DRIVE 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 5,000 watts of continuous power from the AuraGen system. The following page outlines the calculation for the G8500 product line. For systems that will be operating below 5,000 watts, a lower flow rate, motor speed or motor size can be specified. Note that actual system losses due to the hydraulic plumbing, valves and pump are not included in this estimate. Flow and HP Requirements for G5000 systems (5,000 watt continuous output) Definitions: QM = Minimum Flow rate (gallons-per-minute, GPM) ∆P = Pressure difference/drop across the motor (pounds per square inch, PSI) k = Constant (1714) η = Hydraulic motor efficiency at desired generator speed (RPM) HP1 = Horsepower to operate AuraGen at output of 5,000 watts (average 10.5 HP) Flow and HP Requirement Calculations (G8500 systems): QM = k x HP1 ÷ (∆P x η) Required HP for 5,000 watt continuous operation: QSS = 1714 x 10.5 HP ÷ (2,200 PSI x 0.76) = 10.8 gal/min @ 2,800 RPM Required HP for 7,200 watt surge: 10.5 HP x (7,200/5,000) = 15.12 HP For a 7,200 watt surge: QP = 1714 x 15.12 HP ÷ (2,600 PSI x 0.76) = 13.1 gal/min @ 2,800 RPM HP required from motor for 5 kW operation: HPSS = QM(5kW) x ∆P ÷ k = 10.8 GPM x 2,200 PSI ÷ 1714 = 13.8 HP HP required from motor for 7.2 kW surge: HPP = QM(8kW) x ∆P ÷ k = 13.1 GPM x 2,600 PSI ÷ 1714 = 19.9 HP Volumetric Displacement Peak = QM ÷ Motor RPM = 13.1 GPM ÷ 2,800 RPM = 0.0046786 gal/rev; 0.0046786 3 3 gal/rev x 231 in /gal = 1.08 in /rev Flow and HP Requirements for G8500 systems (8,000 watts continuous output) Definitions: QM = Minimum Flow rate (gallons-per-minute, GPM) ∆P = Pressure difference/drop across the motor (pounds per square inch, PSI) k = Constant (1714) η = Hydraulic motor efficiency at desired generator speed (RPM) HP2 = Horsepower to operate AuraGen at output of 8,000 watts (average 16.8 HP) Flow and HP Requirement Calculations (G8500 systems): QM = k x HP2 ÷ (∆P x η)

AURAGEN CATALOG, SECTION 4

Page 4-14

FS-100, JANUARY, 2005

Aura Systems, Inc., (310) 643-5300. www.aurasystems.com

HYDRAULIC DRIVE Required HP for 8,000 watt continuous operation: QSS = 1714 x 16.8 HP ÷ (2,200 PSI x 0.76) = 17.2 gal/min @ 3,400 RPM Required HP for 9,500 watt surge: 16.8 HP x (9,500/8,000) = 20.0 HP For a 9.5 kW Surge: QP = 1714 x 20.0 HP ÷ (2,600 PSI x 0.76) = 17.4 gal/min @ 3,400 RPM HP required from motor for 8 kW operation: HPSS = QM(8 kW) x ∆P ÷ k = 17.2 GPM x 2,200 PSI ÷ 1714 = 22.1 HP HP required from motor for 9.5 kW surge: HPP = QM(9.5 kW) x ∆P ÷ k = 17.4 GPM x 2,600 PSI ÷ 1714 = 26.4 HP

Volumetric Displacement Peak = 3 3 QM ÷ Motor RPM = 17.4 GPM ÷ 3,400 RPM = 0.0051118 gal/rev; 0.005118 gal/rev x 231 in /gal = 1.18 in /rev 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 3,600 RPM and 20.8 GPM and has a displacement of 3 3 1.24 in /rev (20.3 cm /rev). To sustain a 5,000 watt 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 a minimum of 2,800 RPM (3,000 RPM optimal). At these conditions, the necessary flow rate will be roughly 10.8 gallonsper-minute and the horsepower required from the motor is 13.8 HP (see calculations on page 3-6). To sustain a 8,000 watt 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 a minimum of 3,200 RPM (3,400 RPM optimal). At these conditions, the necessary flow rate will be roughly 17.4 gallonsper-minute and the horsepower required from the motor is 22.1 HP (see calculations on page 3-7). 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.

AURAGEN CATALOG, SECTION 4

Page 4-15

FS-100, JANUARY, 2005