WO2001002704A1

WO2001002704A1 - Vertical brushless motor applications

Info

Publication number: WO2001002704A1
Application number: PCT/US2000/018275
Authority: WO
Inventors: Robert F. Birkenstock; Klaus Wolfgang Gebert
Original assignee: Mccord Winn Textron Inc
Priority date: 1999-07-01
Filing date: 2000-06-30
Publication date: 2001-01-11
Also published as: AU6066600A; WO2001002704A9; AU6204200A; WO2001002733A1; WO2001002733A9

Abstract

Applications for vertical brushless motors are disclosed. Particular applications include oil pumps, power steering pumps, water pumps, automatic braking systems, exhaust control valves, compressors, cooling fans, HVAC delivery systems, suspension control systems, window actuators, and convertible top recliners. A novel aspect of the motor/pump combination herein is the integration of the pumping function with the motor, to thereby provide a motor/pump combination with fewer components, less parts, and increased functionality in a given space.

Description

VERTICAL BRUSHLESS MOTOR APPLICATIONS The present invention relates to the application of vertical brushless motors to a variety of unique product applications, specifically automotive applications, wherein the use of vertical brushless motors provides various advantages, including, but not limited to reduced height, width, volume, and weight requirements, longer life, programmable speed control contributing to less audible noise, less power consumption, etc. In addition, the product applications provide improved EMC/RFI, reduced sparking, lower heat build-up and better heat-dissipation, and lower manufacture and investment costs. The preferred motor of the present invention employs so-called "vertical" dc brushless motor technology. Vertical dc brushless motors differ from traditional dc brushless motors in that individual stator pole pieces, each having field windings, are arranged about the periphery of the motor to drive an alternating magnet arrangement, thereby defining a working flux gap that can be parallel or perpendicular to the axis of rotation. One clear advantage of vertical dc brushless motors over conventional dc motors is the ability to increase the amount of torque strength by increasing the distance from the axis of rotation to the stator pole pieces. Another advantage is the increased torque per unit volume of the motor. Also, since the working gap can be arranged perpendicular to the axis of rotation, the vertical motor technology can be made having a smaller profile over conventional dc motor designs. A more detailed discussion of vertical dc brushless motors can be found in U.S. Patent Nos. 4,745,345; 4,837,474; 4,949,000; 5,659,217; and 5,874,796, and each is incorporated herein by reference for the disclosure of vertical dc brushless motor technology. However, while the above discussed vertical brushless configuration is known, its combination and application into various product application thereby presenting the ability to maximize the use of its associated advantages, as applied to automotive applications and the like, has not been explored. Specific examples of the advantages include, but are not limited to, up to a 50% reduction in height, width, and volume, a 20% reduction in weight, a 25% increase in life, and a 30% reduction in cost of the motor. The lower cost is the result of lower manufacturing and investment costs. The manufacturing cost reductions are the result of a simpler bobbin winding, a more efficient use of copper, and the use of smaller motor components. The more efficient use of copper results in lower resistance in the windings which results in better heat dissipation from the stator. The elimination of brush contact with the commutator eliminates brush wear and commutator failure modes. This increases durability and reduces the frequency emissions and voltage spikes. This also makes control of emitted EMI simpler because the EMI is emitted at a predictable frequency. The elimination of brush and commutator contact also reduces sparking which enables the motor to be used in spark sensitive environments. The vertical brushless motor also has better motion control due to lower rotor inertia. Vertical brushless motors also have lower audible noise levels, lower power consumption, and better performance. Vertical brushless motors offer the advantage of more torque out of a smaller (less powerful) motor, and higher achievable speeds. That being the case, it is a principal object herein to uniquely apply the vertical brushless architecture noted above for the use in the various product applications noted herein. More specifically, it is a general object of the present invention to apply vertical brushless technology for the manufacture of product applications, such as hydronic circulators, wiper motors, cruise control systems, electronic power steering motors including rear-wheel steering pumps, fluid pumps including water pumps, fuel pumps, and oil pumps including transmission, power steering and oil lubrication pumps, motors to spool up a turbo charger, a generator to regulate the charge air supply, anti-locking brake systems (ABS), exhaust control valves, automotive air- conditioning compressors, heating/ventilation and air conditioning (HVAC) delivery systems, cooling fans on radiators, controllable suspension systems and active body control pumps including an active suspension, seat recliners, door locks, window actuators/regulators, brake pumps, antenna actuators, convertible top recliners, sun roofs, vacuum cleaners, sun visors, and seat tracks, . In such regard, a more specific object of this invention is to apply vertical brushless motors for pump systems for use in automobiles in general, although the present invention is equally applicable for use in aviation and general machinery (e.g., farm equipment, commercial and residential land equipment, etc.) and more particularly, to any fluid pump system using vertical DC brushless motor technology to drive oil or other fluids. Particular utility of the present invention therefore lies in transmission and engine oil pumps, although any type of oil pump, gerotor, piston, diaphragm or screw can benefit from this technology, and are contemplated herein.

In broad aspect, the present invention herein relates to the integration of vertical brushless DC motor design as applied to applications wherein the mechanism to be driven is integral with the rotor of the motor and not driven off of a motor through pulleys or chains. The vertical brushless motor is the actual driving mechanism. Examples include, but are not limited to, the following product applications in an automobile: coolant circulators, wiper motors, cruise control systems, electronic power steering pumps including four-wheel steering pumps, fluid pumps including water pumps, fuel pumps, and oil pumps including transmission and oil lubrication pumps, anti-locking brake systems (ABS), exhaust control valves, automotive air- conditioning compressors, heating/ventilation and air conditioning (HVAC) delivery systems, cooling fans on radiators, controllable suspension systems and active body control pumps including an active suspension, seat recliners, door locks, window actuators, brake pumps, antenna actuators, convertible top recliners, sun roofs, vacuum cleaners, sun visors, and seat tracks. Non automotive applications include: toy trains, washing machines, golf carts, power tools, weed wackers. CNC machines, medical pumps, recreational vehicles including personal water crafts, wheel chairs, sump pumps, vacuum cleaners, rotating grilles, trolling motors, air line flap control, vacuum cleaner, kitchen appliances, awnings, shutters, gates, fountains, and power lawn mowers. Previously, automotive electrical systems operated at 12vdc. Now with the introduction of 42vdc electrical systems, applications previously thought impractical due to high current requirements are now attainable. Since the new operating voltage is about 3.0 times the previous operating voltage, the amount of power now available is about 3.0 times what was previously available for the same amount of current. Previously, any motor having high power requirements had to be driven off of the engine. Many automotive applications requiring power to drive motors can now benefit from this increase in operating voltage. Many of the pumps and other systems presently installed in automobiles and other vehicles are coupled to the engine for power. These pumps and other systems are most often coupled through belts and pulleys. These belts and pulleys are cumbersome, take up space, transfer power inefficiently, generate audible noise, and wear out over time. Systems using belts and pulleys are often referred to as mechanical systems. Another drawback to these pumps and other systems coupled to the engine is that their location is often compromised because of their need to be near the engine. Another drawback is that these pumps and other systems have their output revolutions per minute (RPM) dictated by the speed of the engine. Certain systems that are coupled to the engine, for example the oil pump and water pump for the transmission, have to be over designed and over sized for a worst-case situation that happens periodically. When the worst-case situation disappears, the system runs inefficiently. It is therefore desirable to have the pump or other system output RPM independent of the engine RPM and further it is also desirable to have the pump or other system output RPM be adjustable. By independent it is meant that the pump or other system output RPM does not have to be proportional to the engine RPM, or that the ratio of the pump or other system output RPM and the engine RPM is not fixed. For example the pump or other system output RPM can independently increase or decrease in a desired quantity based on whatever functional demands are identified for a selected situation. For example, in the context of the present invention, should engine heat reach a particular level, thereby requiring additional cooling via the water pump, such would now efficiently take place herein via the water pump integrated with the vertical brushless design herein. More specifically, the vertical brushless design herein integrated with a water pump is set in communication with a controller for adjusting water pumping output based upon a received signal, said signal indicative of engine heat. As such, the pumping output herein does not depend upon engine speed, which is currently the case of current water pump designs used in standard combustion engine platforms. Along the lines noted above, it can therefore be appreciated that the vertical brushless integrated design herein, as equally applied to a fuel pump, would have the same and significant advantageous features, and unlike the less efficient designs currently in place, allow for increased fuel pumping performance, independent of engine speed considerations. Accordingly, by having the pump or other systems decoupled from the engine, as disclosed herein, the motor herein can be more accurately sized. The output RPM of the pump or other system is now uniquely adjusted based on a received signal, wherein the received signal may be representative of a given demand, wherein said demand may be a consequence of the RPM of the engine, the vehicle velocity, power demand placed upon the engine, ambient temperature conditions, etc. By utilizing vertical brushless technology herein, the output of the pump or other system can now be controlled via a motor controller. A motor controller coupled to the motor can cause the output RPM of the pump or other system to increase, as noted above. Alternatively, the motor controller can cause the pump or other system output RPM to decrease. The signal is preferably an electrical signal, but a mechanical signal will also work. A motor controller coupled to the pump or other system can operate the pump or other system at its most efficient RPM and not be compromised by the engine RPM, as in the case of prior art systems. By using a vertical brushless motor, which has many advantages over prior motors, the vehicle designer now has greater flexibility. The designer can design a vehicle that has an electromechanical design instead of a purely mechanical design. Electromechanical designs are inherently more reliable than mechanical designs due to the reduction in moving parts. More specifically, and by way of representative example of the above various automotive product applications, the present invention relates to an oil pump having a vertically brushless electrically commutated dc motor having a lower profile than conventional dc motors. In accordance with such aspect, the present invention includes a motor controller and the like for adjusting the RPM of the vertical brushless motor based upon a received signal. With respect to the other vertical brushless product applications, in the case of an electric power steering, which makes use of brushless DC motors, the application of vertical brushless motor technology herein significantly provides a reduction in weight and volume. The savings in volume is especially important under the hood of a car where space is at a premium. Similarly, with respect to the use of vertical brushless motors herein as applied to a water pump, currently such motors are engine driven. The use of vertical brushless design herein thereby affords a smaller package, flexible packaging options, flow through design, better/efficient flow at low engine RPM, and the elimination of the thermostat. In addition, the integrated vertical brushless design herein allows, for example, placement of the motor on or within the fan shroud as the fan motor, wherein the motor can run at slow speed due to a received signal indicating that slow speed is sufficient due to flow-through cooling air, and at high speed, when the engine motor itself is shut off. In such regard, with respect to the vertical brushless integrated pumping combination, the pump can be made to run fast when the vehicle itself is moving slowly, or the pump can be made to run slow when the vehicle is moving fast, or made to pump after the vehicle motor is off. Furthermore, the use of the vertical brushless design herein as applied to an ABS, which currently makes uses of pulse-width modulated DC motors, affords a much smaller integrated package. As applied to exhaust control valves, which currently makes use of standard brushless DC motors, the invention herein similarly affords the use of a much smaller integrated package. With respect to A/C compressors, which are currently engine driven, the invention herein provide more efficient scroll type compressors, and smaller/integrated flatter packaging. Finally, with respect to fuel pump, the vertical brushless integrated design herein, apart from its improved functional/performance characteristics over conventional designs, also provides a much improved space-saving profile. More specifically, the design herein provides a fuel pump that is much lower in height than conventional fuel pumps, which in turn allows the fuel tank design to accommodate such motor with improved clearance as between the motor and the fuel tank ceiling. FIG. 1 is a section view of a pump system of the present invention. FIG. 2 is a section view of the motor of the pump system FIG. 1. FIG. 3 is a block diagram of a control system of the present invention. FIG. 4 is a section view of the integrated vertical brushless/fuel pump system of the present invention. It will be appreciated by those skilled in the art that although the following detailed description will proceed with reference being made to the figures above and preferred embodiments, the present invention is not intended to be limited to these preferred embodiments. In order to reduce the amount of wasted energy caused by, e.g. prior art oil pumps, the pump motor will need to be electronically controlled to achieve the RPM appropriate for the current engine demand. Speed control of a vertical brushless technology motor can contribute to lower audible noise levels, less power consumption, and better performance. Vertical brushless technology is also advantageous due to its larger diameter and shorter length than conventional motors. FIG. 1 illustrates the preferred configuration of a pump system 10 of the present invention. The system includes a motor 12, preferably a dc motor, and more preferably a dc motor utilizing vertical brushless technology, with an output drive shaft 14 coupled to a pump 16. FIG. 2 illustrates the internal details of the motor 12 of Fig. 1. The motor 12 comprises an output shaft 14. Preferably, the output shaft 14 is a "D" flange shaft. The output shaft 14 is rotatably secured to the motor casing 32 through a bearing 20. Preferably the shaft 14 is rotatably secured to the motor casing 32 through a plurality of bearings 20. Coupled to the shaft 14 is an optional shaft adapter 22. Coupled to the shaft adapter 22 is a back iron magnet 24. A small air gap 26 separates the back iron magnet 24 from a pole piece 28. Wrapped around the pole piece 28 is the coil 30. FIG. 3 illustrates the preferred control system 40 coupled to an engine 54 and a motor 12. The control system 40 comprises a motor controller 50, a memory 56, which can be a look-up table, and an engine RPM sensor 52 and a vehicle velocity sensor 58. The engine RPM sensor 52 measures the RPM of the engine and the vehicle velocity sensor measures the vehicle velocity. The motor controller 50 receives an input signal from the engine RPM sensor 52 and/or the vehicle velocity sensor 58. The signal is preferably an electrical signal, but a mechanical signal will also work. The motor controller 50 receives the engine RPM signal and/or the vehicle velocity signal and refers to the memory 56 to determine the appropriate output RPM of the motor 12.. The look up table 56 may be different for each engine and motor combination. The motor controller 50 can, e.g. cause the output RPM of the motor 12 to increase as the RPM of the engine or the vehicle velocity increases. Alternatively, the motor controller 50 can cause the output RPM of the motor 12 to decrease as the RPM of the engine or the vehicle velocity increases. In an oil lubrication pump system, the motor controller 50 increases the output RPM of the motor 12, when the engine 54 is at idle RPM, causing an increase in pressure in the pump 16. At highway speeds, the motor controller 50 decreases the output RPM of the motor 12, causing a decrease in pressure in the pump 16, and therefore reducing the amount of wasted energy. FIG. 4 illustrates the invention herein as applied to an integrated vertical brushless/fuel pump design. Specifically, illustrated therein is housing 60, screws 62 and inlet 64. Also shown is shaft 66 and impeller 68 along with magnet 70. A spacer 72 is then provided followed by outlet 82 and bobbin/coil assembly 84, stator 86 and cover/outlet 88. As can therefore be seen, such design provides a novel integrated motor/fuel pump combination, with fewer components, less parts, and more function in a given space, than prior art designs. In sum, as described above, the present invention provides, e.g. a pump system having a lower profile over traditional motor designs, and which includes a control system that responds to a received signal, representative of engine RPM and/or vehicle velocity to conserve energy, or any other vehicle operational variable that one desires to select/monitor. The variable-speed motor control arrangement disclosed herein allows the motor pump to operate at an appropriate pressure and thus reduce energy losses. The pump can uniquely operate at its highest pressure at idle RPM and also operate at lower pressures as the engine RPM is increased. In such regard, the present invention broadly provides an oil pump system, comprising a motor, an oil circulating pump driven by the vertical brushless motor, and a motor controller coupled to the motor for adjusting the motor/pump output based on a received signal. Those skilled in the art will appreciate that still other modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than literally described, but fall within the scope therein

Claims

We claim: 1. An oil pump system, comprising: a motor, an oil circulating pump driven by the motor, and a motor controller coupled to the motor for adjusting the motor output RPM based on a received signal.

2. The oil pump system of claim 1, wherein the received signal is a signal representative of the revolutions per minute of an engine.

3. The oil pump system of claim 1, wherein the received signal is a signal representative of a vehicle velocity

4. The oil pump system of claim 1 wherein the received signal is an electrical signal.

5. The oil pump system of claim 1 wherein the revolutions per minute of the oil circulating pump is independent of the engine revolutions per minute

6. The oil pump system of claim 1, wherein the motor controller increases the motor output revolutions per minute as the revolutions per minute of the engine decreases.

7. The oil pump system of claim 1, wherein the motor comprises a vertical dc brushless motor.

8. The oil pump system of claim 1, wherein the motor controller comprises a memory for storing a relationship between an engine revolutions per minute and a desired motor output revolutions per minute.

9. The oil pump system of claim 8, wherein the memory is a look-up table.

10. A power steering pump system, comprising: a motor, a fluid circulating pump driven by the motor, and a motor controller coupled to the motor for adjusting the motor output RPM based on a received signal.

11. The power steering pump system of claim 10, wherein the motor comprises a vertical dc brushless motor.

12. The power steering pump system of claim 10 wherein the RPM of the fluid circulating pump is independent of the engine RPM.

13. A vehicle fluid pump system, comprising: a motor, a fluid circulating pump driven by the motor, and a motor controller coupled to the motor for adjusting the motor output revolutions per minute based on a received signal.

14. The fluid pump system of claim 13, wherein the motor comprises a vertical dc brushless motor.

15. The fluid pump system of claim 13. wherein the fluid is water.

16. The fluid pump system of claim 13. wherein the fluid is oil.

17. The fluid pump system of claim 13. wherein the fluid is a coolant.

18. The fluid pump system of claim 13 wherein the fluid is gasoline.

19. A ventilation system, comprising: a motor, a fan driven by the motor, and a motor controller coupled to the motor for adjusting the motor output revolutions per minute based on a received signal.

20. The ventilation system of claim 19, wherein the motor comprises a vertical dc brushless motor.

21. The ventilation system of claim 19, wherein the sigpal is a vehicle velocity signal.

22. An engine, motor, and fluid pump combination for a vehicle, wherein said motor is engaged to and drives said pump to pump fluid, and wherein said motor engaged to said pump provides a selected driving force to said pump based upon a received signal.

23. The engine, motor, and fluid pump combination of claim 22, further comprising: a motor controller for controlling the motor driving force, the motor controller receiving said signal from an engine RPM sensor and or a vehicle velocity sensor, and a memory module in communication the motor controller for determining the appropriate motor driving force based on said signal from the engine RPM sensor and/or the vehicle velocity sensor.

24. The engine, motor, and fluid pump combination of claim 22, wherein said motor is a vertical brushless DC motor.

25. The engine, motor, and fluid pump combination of claim 22, wherein said pump is an oil lubrication pump.

26. A power steering pump for a vehicle, comprising a vertical DC brushless motor, a fluid circulating pump drive by said motor, and a motor controller coupled to the motor for adjusting the motor output RPM based upon a received signal.

27. A transmission fluid pump for a vehicle, comprising a vertical DC brushless motor a fluid circulating pump driven by said motor, and a motor controller coupled to the motor for adjusting the motor output RPM based upon a received signal.

28. A brake system pump for a vehicle, comprising a vertical DC brushless motor a fluid circulating pump drive by said motor, and a motor controller coupled to the motor for adjusting the motor output RPM based upon a received signal.