ZA201001414B - Hybrid drive system - Google Patents

Description

HYBRID DRIVE SYSTEM :

Field of the Invention "The invention relates to a hybrid drive system using two different drive means.

Background of the invention

The inventor is aware of drive means such as electrical motors, fuel combustion engines, and the like. The inventor is also aware of the extensive use of hydraulic power systems including hydraulic motors, pumps, and control systems such as that - used on some aircraft and on earth moving equipment. : :

Furthermore, the search for improved efficiency drive systems is urgent in an effort to save fuel as well as to reduce pollution. : -

Considering the above the inventor now proposes a combination of an electrical or fuel combustion drive system with one or more hydraulic power system to form a hybrid drive system of the invention.

Summary of the invention : According to the invention, there is provided a hybrid drive system which includes:- - a slave drive system for pressurizing a hydraulic fluid; and - a primary drive system including one or more hydraulic motors that are in use driven by the hydraulic fluid; wherein the slave system actuates the primary drive system into an operative condition and wherein, once the primary drive system is in the operative condition, it is disconnected from the slave drive - : system and continues to remain in the operative condition for a period.

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The slave drive system is referred to as “System 1” and the primary drive system is : referred to as “System 2” in what follows below. RE

System 1 may include an electrical or fuel driven engine. "The hybrid drive system may be used in most types of motorised equipment. =

System 1's engine may drive a hydraulic pump which supplies hydraulic fluid flow and 10. pressure for starting system 2. System 1 may include a hydraulic fluid reservoir. SE oo

The hybrid drive system may include pressure lines and filters sized for the required high and low pressure flows.

One or more check valves may be installed to avoid reverse fluid flow in the systems.

In the case where system 1 includes a combustion engine, hydraulic fluid may be - cooled by integrating hydraulic fluid flow through a fuel tank of system 1 thus decreasing : hydraulic fluid temperature and increasing fuel temperature resulting in better : 20 combustion in the engine in both systems 1 and 2. Alternatively, or additionally, the

E . hydraulic fluid may be cooled by a cooling fluid such as liquid nitrogen.

The hydraulic motors of system 2 may be torque motors, which torque motors are used for forward and reverse direction, especially if a gearbox is not used. . 25. : oo .

Hydraulic pressure lines may be provided to the torque motors for the driving motion.

Lines are required for both forward and reverse directions if a gearbox is not used, and an additional return line for fluid returning to the hydraulic fluid reservoir. | :

An accumulator may be installed to avoid pressure loss during normal operation. . A selector valve may be used to first select optional equipment and then a drive method.

Hydraulic fluid from all components may be returned through a fuel oil heat exchanger.

Hydraulic fluid flow may be achieved through HP/LP flex, ridged hoses and pipes.

Hydraulic reservoir pressurisation may be achieved through exhaust gas and or precharged by means of Schroder valve to supply hydraulic pump with constant fluid supply. ~ One or more PTU (power transfer unit) may supply a parallel system with only one engine in system 1 supplying pressure to the whole of system 2 and optionally a parallel system 2.

A hydraulic motor of system 2 may drive an electrical generator to generate electricity.

The generator may drive an electrical hydraulic pump which may supply system 2 with pressurized hydraulic fluid once system 2 has been disconnected from system 1.

When system 1 is in use, an isolation valve opens system 2 which will take over as the primary drive system by means of a priority valve or automatic selector valve and thus system 1 engine driven pump may be disconnected so that system 2 operates : 20 independently of system 1's engine and system 1's engine may be shut ‘down with system 2's hydraulic pump or pumps supplying hydraulic fluid flow. oo A hydraulic motor or a permanent magnet actuator may replace a generator as the propulsion method for electric pump/engine driven hydraulic pumps of the hybrid drive system. : ~The power from the main engine of system 1 may be substituted with power from a

PMA engine driven pump. 30. A permanent magnet actuator driven pumpmay also be used to pressurise an accumulator and reservoir manually or automatically via a compressor type cycle machine. + Over pressure valves may be installed where and when necessary pending usage.

An oxygen air mixture or other suitable pressurized gas cylinder may to be used for running’ aircraft with the system at high altitudes using petrol, diesel or hydrogen engines for system 1 thereof.

In mining equipment the hybrid drive system may use, for system 1, an external electric pump or power source. Thus by means of electric cables the electric hydraulic fluid pump can be used to supply equipment underground connected through hoses and cables thus eliminating underground CO, pollution.

Accumulator pressure may be achieved by precharging same. Shut-off valves and bleeding points may be provided as per requirement.

E © An alternator may be connected to torque motors, permanent magnet actuators, pumps, : drive means, or power transfer units to create electro-magnetic field for increased permanent magnet actuator field.

A dynamo may be tapped off torque motors, gearboxes and the like to supply simpler systems, for example, cooling fans, and lights. - Description of an Embodiment of the Invention Co

The invention will now be described, by way of the following, non-limiting example only.

Inthe drawings:- SL

Figure 1 shows a schematic layout of a slave drive system in accordance with the present invention;

Figure 2 shows a first schematic layout of a hybrid drive system including a slave and primary drive system, in accordance with the present invention; and

Figure 3 shows a second schematic layout of a hybrid drive system including a slave and primary drive system, in accordance with the present invention. oo } .

. The reference numerals in Figures 1 and 2 indicate equipment as set out below; 1. Engine © 5 An internal combustion, gas turbine, hydrogen engine relevant to size of equipment that is needed for use. 2. Hydraulic engine driven pump 2A electrical driven pump :

Connected to item 1 and in operation will supply hydraulic pressure and flow depending on size and type of hydraulic pumps. 3. HP/LP (high pressure / low pressure) filters

Filters to clean fluid in systems with clogging pop up indicators. 3A" Over pressure valve

Over pressure valve to return fluid to return line in case of over pressure in system.

Cw : oo 4, Ridged and flexible hoses/pipes ~ Ridged and flexible hoses/pipes to be used to connect components and return fluid to reservoir as per requirements and functionality. : 5. Hydraulic fluid frequency damper

To reduce the frequency created by hydraulic engine and electrical driven pump so that fluid is at a constant reduced pulsating flow. 8. Check valves (one way valves)

To eliminate reverse flow in the system.

7. Priority valve/automatic selector valve

Priority/automatic selector valve selects aggressive oncoming pressure as dominant supply. These typically operate on a difference in actuator surface area. ~ 8. MPPM-Motor pump-pump motor (PTU-Power transfer unit) 8A. Isolation valve 10. Power transfer unit aids in using flow from one system to supply another parallel system without fluid transfer. PTU optional. 8A. Isolation valve isolates system 1 and 2. With or without PTU function 9. Hydraulic reservoir ~~ Main function to store and supply fluid to engine/electrical driven pump for systems use.

Pressurised by external source and/or exhaust gas if and when required. 10. Accumulator

Function to provide flow during transient flow demands; Example: bladder, piston type 11. Selector valve oo | Co 11A. Piston type actuators

Selections through selector valve will enable various options of flow to torque motors as required. All selections to be made by primary and secondary selector valves.

Example:2 x4;4x4;2x4AUX; 4 x 4 AUX : ~ 11A. Piston type actuators to meet operational requirements capable of locking in place at maximum potential operation. Pressure line pressure breaks internal hydraulic lock and allows actuators to retract and extend.

lo 12. Metering valve ~ Metering valve determines amount of flow to torque motors by means of a segmented modulating type valve and allows generator torque motor to run at a constant speed. 13. Torque motors

Torque motors convert hydraulic fluid pressure and flow into mechanical power output, number of torque motors as per operational requirements. : C1 3A. Permanent magnet actuator (PMA) / Optional Co

A type of magnetic actuator, whether cone, cylinder, or swash plate is an additional option to supply item 13, 14, 18, 18A. PMA to also have electro magnet capabilities (dynamo; alternator) as indicated in the diagram.

To rotate the PMA pressure is required in the stator part thereof which will allow cone part to rotate due to magnets placed on both stator and cone. The strength of the PMA _ is determined by the magnet sizes and strength, bearings, seals and universal joints as required. A variable guidance ring may be operated by a piston type actuator or actuators to assist the PMA. 13B. Gearbox

A gearbox is used in aiding torque motors to increase/decrease speed, direction, and torque etc. 13C. Ring gear : oo

Ring gear is used to facilitate multiple torque motor synchronised operation. 14. Generator

Generator to supply system 2 with power to electrical hydraulic 20 S enabling system 2 to operate independently. PMA other option as system 2's engine driven pump. 15. Drive method

This will be the method of propulsion motion for example wheels props tracks etc. oo 15A. - Friction plates

To aid and avoid shearing shafts during transient drive rotation demands and extreme loads. 16. Oxygen cylinder : A compressed air oxygen mixture cylinder to facilitate aircraft operation at altitude. 16A. Catalytic converter ; 20 To convert CO; gas into cleaner air if needed but not needed for gas turbines. 17. Selector secondary (PMA)

Selects PMA actuator position capable to lock in position at full load on all equipment example engine/electrical driven hydraulic pumps. : 18. Dynamos

To enable alternative power supply in all aspects of system. 18A. Alternator

To facilitate power to electro magnets rectifying current and increasing PMA strength.

19. Electrical system

All electrical components and circuits as per required. Example: temperature sensors, pressure sensors, wiring, transformer rectifiers etc. oo :

Example of Operation of hybrid drive system

The hybrid drive system as illustrated may be operated as per the following step:

Step 1

Start system 1 engine : ‘Step2

Open system 2 isolation valve

Step3 ) 20 Confirm pressure on system 2 sufficient ~ Step4

Confirm priority/automatic valve open to system 2 : 25 : . Step5- Co

Make drive selection/height etc. © 30 Step6

Meter flow to torque motor

Step?

SE ¥2010/014 1

Shut down system 1 engine

Step 8 ~ System 2 now in operation with all system 1 capabilities :

Step 9 © 10 To shutdown system 2 release press out of pma and close isolation valve. ~~ ~~ = tis to be appreciated, that the invention is not limited to any particular embodiment or configuration as hereinbefore generally described or illustrated. oo

Claims (24)

om 1] DS

1. A hybrid drive system including:- - a slave drive system (system 1) for pressurizing a hydraulic fluid; and CL - a primary drive system (system 2) including one or more hydraulic motors that are in use driven by the hydraulic fluid; wherein the slave system actuates the primary drive system into an operative condition and wherein, once the primary drive system is in the operative condition, it is disconnected from the - slave drive system and continues to remain in the operative condition for a period. B a

2. A hybrid drive system as claimed in claim 1, wherein system 1 includes an a engine selected from an electrically driven engine and a fuel driven engine. . 15

3. A hybrid drive system as claimed in claim 1 or claim 2, wherein the engine of system 1 engine drives a hydraulic pump which supplies hydraulic fluid flow and pressure for actuating system 2 into the operative condition.

4. A hybrid drive system as claimed in any one of claims 1 to 3, wherein system 1 oo ‘includes a hydraulic fluid reservoir.

S. A hybrid drive system as claimed in any one of the preceding claims, wherein the system includes pressure lines and filters sized for high and low pressure fluid iE flows within the system.

6. A hybrid drive system as claimed in any one of the preceding claims, wherein the system includes one or more check valves to inhibit reverse fluid flow in the systems.

30. 7. A hybrid drive system as claimed in any one of the preceding claims, wherein, when the engine of system 1 is a combustion engine, the hydraulic fluid is cooled by integrating hydraulic fluid flow through a fuel tank of system 1 thus decreasing hydraulic fluid temperature and increasing fuel temperature resulting in better : : combustion in the engine in both systems 1 and 2.

: 8. A hybrid drive system as claimed in claim 7, wherein the hydraulic fluid is alternatively/ additionally cooled by a refrigerant. Co

9. A hybrid drive system as claimed in any one of the preceding claims, wherein the hydraulic motors of system 2 are torque motors, which are used for forward and reverse direction, particularly when a gearbox is not used.

10.A hybrid drive system as claimed in claim 9, wherein hydraulic pressure lines are

10. provided to the torque motors for the driving motion. CL Co

11.A hybrid drive system as claimed in any one of the preceding claims, wherein an : accumulator is provided to inhibit pressure loss during normal operation.

12.A hybrid drive system as claimed in any one of the preceding claims, wherein a selector valve is used to first select optional equipment and then a drive method. .

13.A hybrid drive system as claimed in any one of the preceding claims, wherein hydraulic fluid from all components of the system is returned through a fuel oil heat exchanger.

14.A hybrid drive system as claimed in any one of the preceding claims, wherein hydraulic fluid flow is achieved through HP/LP flex, ridged hoses and pipes.

25. 15.A hybrid drive system as claimed in any one of the preceding claims, wherein pressurization of the hydraulic reservoir is achieved through exhaust gas and/or precharged by means of Schroder valve to supply the hydraulic pump with a constant fluid supply.

16.A hybrid drive system as claimed in any one of the preceding claims, wherein one or more PTU (power transfer unit) supply a parallel system with only one engine in system 1 supplying pressure to the whole of system 2 and optionally a parallel system 2. | 0 g oo 13 oo

17.A hybrid drive system as claimed in any one of the preceding claims, wherein a hydraulic motor of system 2 drives an electrical generator to generate electricity : for driving an electrical hydraulic pump which supplies system 2 with pressurized hydraulic fluid after system 2 has been disconnected from system 1.

18.A hybrid drive system as claimed in any one of the preceding claims, wherein a hydraulic motor or a permanent magnet actuator replaces a generator as the propulsion method for electric pump/engine driven hydraulic pumps of the. hybrid drive system. Co

19. A hybrid drive system as claimed in any one of the preceding claims, wherein the Co power from the engine of system 1 is substituted with power from a PMA engine driven pump.

20.A hybrid drive system as claimed in any one of the preceding claims, wherein a g permanent magnet actuator driven pump is used to pressurise an accumulator and reservoir manually or automatically via a compressor type cycle machine.

21.A hybrid drive system as claimed in any one of the preceding claims, wherein an alternator is connected to torque motors, permanent magnet actuators, pumps, drive means, or power transfer units to create electro-magnetic field for increased permanent magnet actuator field.

22. A hybrid drive system as claimed in any one of the preceding claims, wherein a dynamo is tapped off torque motors, gearboxes and the like to supply simpler oo systems, for example, cooling fans, and lights with electrical power.

23.A hybrid drive system according to the invention, substantially as hereinbefore described or exemplified. C30 Ce I | :

24. A hybrid drive system as specifically described with reference to or as illustrated in any one of the accompanying drawings.

~ 25.A hybrid drive system including any new and inventive integer or combination of integers, substantially as herein described.

DATED AT PRETORIA THIS 26™ DAY OF FEBRUARY 2010. . Co - EVERSHEDS Applicant's Attorneys