SAE J2311-1999 Automatic Transmission Hydraulic Pump Test Procedure.pdf

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SURFACE VEHICLE 400 Commonwealth Drive, Warrendale, PA 15096-0001 RECOMMENDED PRACTICE Submitted for recognition as an American National Standard J2311 ISSUED JAN1999 Issued1999-01 Automatic Transmission Hydraulic Pump Test Procedure 1.Scope This SAE Recommended Practice provides a method to determine the performance characteristics of the hydraulic oil pumps used in automatic transmissions and automatic transaxles. This document outlines the specific tests that describe the performance characteristics of these pumps over a range of operating conditions and the means to present the test data. This document is not intended to assess pump durability. 2.References 2.1Applicable Publications The following publications form a part of this specification to the extent specified herein. Unless otherwise specified, the latest issue of all publications shall apply. 2.1.1SAE PUBLICATIONS Available from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001. SAE J1276 Standardized Fluid for Hydraulic Component Tests SAE J1165 Reporting Cleanliness Levels of Hydraulic Fluids 2.1.2ISO PUBLICATION Available from ANSI, 11 West 42nd Street, New York, NY 10036-8002. ISO 4412-1 Hydraulic fluid power Test code for determination of airborne noise levels Part 1: Pumps ISO 4412-3 Hydraulic fluid power Test code for determination of airborne noise levels Part 3: Pumps Method using a parallelepiped microphone array NFPA T2.6.1 Method for Verifying the Fatigue and Static Pressure Ratings of the Pressure Containing Envelope of a Metal Fluid Power Component 2.2Related Publications The following publications are provided for information purposes only and are not a required part of this document. 2.2.1SAE PUBLICATIONS Available from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001. SAE J745 Hydraulic Power Pump Test Procedure SAE J1116 Categories of Off-Road Self-Propelled Work Machines SAE J2311 Issued JAN1999 -2- 3.Definitions 3.1Actual Capacity The measured output flow at prescribed conditions of pressure, speed, and temperature. It is actual flow rate delivered from the pump discharge port while operating at the prescribed conditions. 3.2Actual Displacement See 3.23. 3.3Actual Torque The measured input torque required to operate the pump at prescribed conditions of pressure, temperature, and speed. It includes frictional losses. 3.4Aeration The mixing beyond the solution point of gas and fluid so as to provide a fluid medium having two distinct phases, namely one liquid, and one gaseous. 3.5Airborne Noise Pressure fluctuation of the ambient air surrounding a vibrating element, the magnitude of the pressure fluctuations being sufficient for the human ear to sense sound, the threshold of which is near 2.065x105 Pa. 3.6Axial Thrust Capacity An externally applied force applied to the pump assembly. It may be applied to the housing which carries the force to ground or applied to the input shaft which transmits the force to the pumping elements. 3.7Bulk Modulus The reciprocal of compressibility. A measure of fluid “ stiffness,” expressed in pressure units, defined as Differential Pressure/(Initial volume Final volume). Secant Bulk Modulus is the average between two points on the Bulk Modulus curve. The Tangent Bulk Modulus is the value at a specific point on the curve. 3.8Cavitation The formation of bubbles or vapor “cavities” in liquid when the local static pressure is reduced to or below the fluid vapor pressure. 3.9Critical Inlet That operating condition of constant speed and inlet temperature, and decreasing suction pressure artificially, that results in less than complete filling of the pumping chamber. 3.10 Direction of Rotation When viewed from the pump drive shaft end, the clockwise (right hand) or counter- clockwise (left hand) rotation of the shaft that produces discharge from the discharge port. 3.11 Discharge Pressure The static pressure at the pump discharge port, downstream of the confluence of all pumping chambers. 3.12 Entrained Air The result of aeration. The mixture of undissolved gas, usually air, beyond the solution point, usually expressed in percent air by volume. 3.13 Erosion The damage, loss of material, or permanent deformation of pressure containing surfaces as the result of collapsing bubbles, either from aeration or cavitation. 3.14 Fluid Borne Noise The oscillations of fluid static pressure resulting from fluid disturbances due to discharging pump chambers, standing waves, oscillating valves, or other disturbances. The resulting wave form has amplitude and frequency characteristics similar to airborne noise 3.15 Head Loss A loss in total energy of a fluid in motion, usually the result of frictional losses in conduits, but often includes component losses (orifices, valves, etc.) and energy loss from work exerted on the system. Also known as “Pressure Drop.” SAE J2311 Issued JAN1999 -3- 3.16 High-Speed Fill Limit The rotative speed at which the pump delivery/speed curve diverges from theoretical. It is differentiated from “Critical Inlet“ in that the inlet port is unrestricted. The divergence results from the inability of the available inlet energy to accelerate the inlet fluid to a velocity equal to the moving pump inlet chambers. “Theoretical HSFL” is calculated assuming no inlet losses. 3.17 Hydraulic Output Power The fluid power, expressed in power units, available to do useful work. See Equation 1. (Eq. 1) 3.18 Inlet Pressure The static pressure at the pump inlet port upstream of the pumping chambers. 3.19 Leakdown Rate The rate, expressed in time units, that characterizes the ability of a pump assembly with all ports closed and sealed to maintain a vacuum above a specified level. A measure of air infiltration. 3.20 Maximum Rated Pressure The maximum nominal (excludes tolerances and pulsation) discharge pressure the pump is designed to operate at continuously for a specified period. 3.21 Maximum Rated Speed The maximum input speed the pump is designed to operate at continuously for a specified period. 3.22 Maximum Rated Temperature The maximum fluid temperature at the pump inlet the pump is designed to operate at continuously for a specified period. 3.23 Measured Displacement That measured amount of volume displaced through one revolution by a positive displacement machine. The Measured Displacement does not include any losses for pump internal leakage. May also be known as “Actual Displacement”. 3.24 Mechanical Efficiency The ratio, expressed in percent of Theoretical Torque to Actual Torque. See Equation 2. (Eq. 2) 3.25 Mechanical Input Power The mechanical (shaft) power, expressed in power units, consumed by the pump. See Equation 3. (Eq. 3) 3.26 Overall Efficiency The ratio, expressed in percent, of Output Power to Input Power. See Equation 4. (Eq. 4) 3.27 Over Pressure Rating The maximum discharge pressure the pump is expected to endure without permanent damage. After exposure to this condition, and upon return to operation within designed “ Maximum Ratings”, (see 3.20 through 3.22) all performance requirements must be met. See Figure 1. 3.28 Over Speed Rating The maximum input speed the pump is expected to endure without permanent damage. After exposure to this condition, and upon return to operation within designed “Maximum Ratings, (see 3.20 through 3.22) all performance requirements must be met. See Figure 1. 3.29 Over Temperature Rating The maximum inlet temperature the pump is expected to endure without permanent damage. After exposure to this condition, and upon return to operation within designed “Maximum Ratings, (see 3.20 through 3.22) all performance requirements must be met. See Figure 1. HoutW QaPdPi()× 60 -= Em%() Tt Ta - 100%×= HinW TaN× 9.549 - -= Eo%() Hout Hin - 100%×= SAE J2311 Issued JAN1999 -4- FIGURE 1 PUMP DESIGN/APPLICATION DATA SHEET SAE J2311 Issued JAN1999 -5- 3.30 Power Loss The power lost by the pump, usually in the form of heat, expressed in power units. It is the difference between input and output power. See Equation 5. (Eq. 5) 3.31 Pressure Ripple The peak-to-peak amplitude of fluid pressure oscillations. 3.32 Pump Delivery The actual flow rate from the discharge port at a specified pressure, inlet temperature, and speed. 3.33 Radial Bearing Capacity The maximum permitted force applied to the input shaft the pump is required to support, e.g., offset load. May be specified as a moment and force, or force at defined distance from bearing. 3.34 Rated Fatigue Pressure That pressure which the pressure containing envelope can sustain for 10X106 cycles without failure, defined as any fracture, crack, excessive seal leakage caused by deformation, or any permanent deformation which interferes with related component function. 3.35 Slip Flow The difference between Pump Delivery (actual flow) and Theoretical Capacity, usually referred to as “internal leakage.“ 3.36 Sound Power The measure of total sound energy radiated from a theoretical point source, expressed in decibels. 3.37 Tare Torque The torque required to overcome bearing and seal drag, and is not a component of the lost work due to pumping mechanism inefficiency. May be included in Pump Assembly measurements to ascertain total power draw. 3.38 Theoretical Capacity The theoretical output flow at a given speed. It assumes 100% volumetric efficiency, is independent of discharge pressure, and is a function of Measured Displacement, “Dm” and Input Speed, “N.” See Equation 6. (Eq. 6) 3.39 Theoretical Displacement The calculated volume displaced by the pump mechanism in one rotation. It is derived from the geometry of the pumping mechanism and assumes 100% volumetric efficiency. 3.40 Theoretical Torque The theoretical torque required to rotate the pump input shaft due to an assumed pressure rise between pump inlet and discharge ports. It is a function of Measured Displacement, “ Dm” and differential pressure, and does not include frictional losses. See Equation 7. (Eq. 7) 3.41 Torque Ripple The peak-to-peak amplitude of torsional oscillations measured at the pump input shaft. 3.42 Volumetric Efficiency The ratio, expressed in percent, of Pump Delivery to Theoretical Capacity. See Equation 8. (Eq. 8) HlW HinHout= Qtlpm DmN× 1000 -= TtNmPdPi() Dm 21000×× - = Ev% Qa Qt - 100%×= SAE J2311 Issued JAN1999 -6- 4.Symbols EmMechanical Efficiency (%) EoOverall Efficiency (%) EvVolumetric Efficiency (%) QtTheoretical Capacity (Lpm) QaActual Capacity (Lpm) DmMeasure Displacement (cc/rev) NPump Rotational Speed (rpm) HoutHydraulic Power output (Watts) HinMechanical Power Input (Watts) HlPower Loss (Watts) TtTheoretical (Input) Torque (Nm) TaActual (Input) Torque (Nm) PiPump Inlet Pressure (kPa) PdPump Discharge Pressure (kPa) WPower units, (Watts) Lpm Flow rate units, (liters per minute) NmTorque units, (Newton-Meters) 5.Test Preparation During installation of the pump into a mounting fixture, special attention should be focused on properly aligning the pump, torque transducer, and drive motor. These component centerlines should be aligned to within 0.025 mm (0.001 in) or within “Pump Design/Application Data Sheet” (see Figure 1) requirements, whichever is more restrictive. Initially, all components should be checked with a dial indicator to obtain a coarse alignment. Final alignment must be completed, verified, and documented in accordance with local laboratory practice. 5.1Material and Apparatus 5.1.1TEST FLUID Test fluid shall be per SAE J1276 (a non-synthetic based fluid, preferably “DEXRON III” or equivalent) and approved by the manufacturer of the unit. The fluid must be identified on the pump build sheet, test data sheets, or laboratory log. Fluid properties must be included in any report. 5.1.2RESERVOIR The inlet circuit should include a sight glass to verify no visible air is in the inlet stream. To minimize aeration, return fluid for all circuits other than atmospheric drain lines shall enter the reservoir at a point below the surface of the fluid and shall be diffused in such a manner as to minimize turbulence in the reservoir. Include a “Re-circulation Circuit“ to minimize inlet losses if the application provides such a feature. See Figures 2A through 2C. Filtration shall be provided to maintain fluid cleanliness level, as defined by SAE 1165, within the pump manufacturer s recommendations. The test circuit and reservoir shall be configured to replicate as closely as practical the characteristics of the given application, e.g., inlet pressure drop, velocity, etc. See Figure 1. The Pump Design/Application Data sheet must accompany each test specimen model. A temperature probe shall be placed as close as practical to the inlet strainer and within the stream lines of the inlet flow to record inlet fluid temp. Appropriate fluid conditioning and auxiliary circuits must be installed to control temperature and cleanliness. The system may be designed to also provide hydraulic signals for integral Pump Controls. (See Figures 2A through 2C). SAE J2311 Issued JAN1999 -7- FIGURE 2A TEST CIRCUIT FIXED DISPLACEMENT PUMP FIGURE 2B TEST CIRCUIT FIXED DISPLACEMENT PUMP WITH INTEGRAL PRESSURE CONTROL SAE J2311 Issued JAN1999 -8- FIGURE 2C TEST CIRCUIT VARIABLE DISPLACEMENT PUMP WITH INTEGRAL PRESSURE COMPENSATOR (MAIN PRESSURE REGULATOR) CONTROL 5.1.3DATA ACQUISITION EQUIPMENT Verify calibration of all data acquisition equipment and record in test log or data sheet. Install instrumentation sufficient to obtain the data in Table 1: NOTE Future applications may require extended calibration limits, e.g., high-pressure pumps used in heavy-duty, high-speed, or CVT transmissions. See Figure 1. TABLE 1 DATA ACQUISITION EQUIPMENT DataUnitsCalibration Range Input Shaft Speedrpm0 - 8000 Input TorqueNm0 - 60 Discharge Flow, low-rangelpm 0.1 - 50 Discharge Flow, high-rangelpm 5 - 200 Discharge Pressure, low rangekPa0 - 700 Discharge Pressure, high rangekPa 0 - 3500 Throttle Valve Pressure SignalkPa0 - 700 Boost Pressure SignalkPa 0 - 3500 Inlet Temperature°C0 - 150 Resp