Patent Publication Number: US-2010122864-A1

Title: Hybrid hydraulic drive system for all terrestrial vehicles, with the hydraulic accumulator as the vehicle chassis

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     International classification . . . B60K 3/00; B60K 6/12; B60K 6/02; B60K 6/00; B60K 17/00; B60T 8/64; B62M 1/10; F15B 1/02; F16D 31/02; F04B 49/00; G06F 17/00 
     U.S. Cl . . . 180/165, 105/96.2, 105/238.1 180/365; 180/307,367,303/152; 60/408, 413, 414,415, 416, 418, 448, 449; 701/69; 903/941 
     Field of classification search . . . 105/96.2; 180/165, 180/365; 180/305, 306, 307,367,303,152; 280/212, 216; 303/112, 303/152, 303/113, 1, 10, 11, 413, 414, 416, 60/408, 409,413, 414, 416, 418,448,449; 701/69; 903/941 
     REFERENCES CITED 
     U.S. PATENT DOCUMENTS 
       
     
       
         
           
               
               
               
               
             
               
                   
               
               
                   
                   
                 Inventor&#39;s 
                   
               
               
                 US patent No 
                 Date issued 
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                 Classification 
               
               
                   
               
             
            
               
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                 August 1920 
                 Swanson 
                 180/165 
               
               
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                 March 1933 
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                 180/165 
               
               
                 3,680,313 
                 August 1972 
                 Brundage 
                  60/460 
               
               
                 3,892,283 
                 July 1975 
                 Johnson 
                 180/165 
               
               
                 3,913,453 
                 October 1975 
                 Parquet 
                  60/493 X 
               
               
                 4,077,211 
                 March 1978 
                 Fricke 
                  60/428 
               
               
                 4,098,083 
                 July 1978 
                 Carman 
                  60/484 
               
               
                 4,098,144 
                 July 1978 
                 Besel 
                  74/661 
               
               
                 4,132,283 
                 January 1979 
                 McCurry 
                 180/165 
               
               
                 4,215,545 
                 August 1980 
                 Morello 
                  60/414 X 
               
               
                 4,227,587 
                 October 1980 
                 Carman 
                 180/165 
               
               
                 4,351,409 
                 September 1982 
                 Malik 
                 180/165 
               
               
                 4,356,773 
                 November 1982 
                 van Eyken 
                 105/238.1 
               
               
                 4,387,783 
                 June 1983 
                 Carman 
                 180/168 
               
               
                 4,592,454 
                 June 1983 
                 Michel 
                 192/3.23 
               
               
                 4,741,410 
                 May 1988 
                 Tunmore 
                 180/165 
               
               
                 4,745,745 
                 May 1988 
                 Hagin 
                  60/413 
               
               
                 4,754,603 
                 July 1988 
                 Rosman 
                  60/413 
               
               
                 4,760,697 
                 August 1988 
                 Heggie 
                  60/408 
               
               
                 4,825,774 
                 May 1982 
                 Tani 
                 105/141 
               
               
                 4,964,345 
                 October 1990 
                 Porel 
                 105.96.2 
               
               
                 4,986,383 
                 January 1991 
                 Evans 
                 180/165 
               
               
                 5,024,489 
                 June 1991 
                 Tanaka 
                 303/3 
               
               
                 5,088,041 
                 February 1992 
                 Tanaka 
                 701/70 
               
               
                 5,495,912 
                 March 1996 
                 Gray 
                 180/165 
               
               
                 5,505,527 
                 April 1996 
                 Gray 
                  60/413 
               
               
                 5,545,928 
                 August 1996 
                 Kotani 
                 290/40C 
               
               
                 5,579,640 
                 December 1996 
                 Gray 
                  60/413 
               
               
                 5,794,734 
                 August 1998 
                 Fahl 
                 180/165 
               
               
                 5,887,674 
                 March 1999 
                 Gray 
                 180/307 
               
               
                 6,109,384 
                 August 2000 
                 Bromley 
                 180/242 
               
               
                 6,170,587 
                 January 2001 
                 Bullock 
                 180/69.6 
               
               
                 6,223,529 
                 May 2001 
                 Achten 
                  60/416 
               
               
                 6,311,797 
                 November 2001 
                 Hubbard 
                 180/165 
               
               
                 6,378,444 
                 April 2002 
                 Dastas 
                 105/396 
               
               
                 6,629,573 
                 October 2003 
                 Perry 
                 180/54.1 
               
               
                 6,719,080 
                 April 2004 
                 Gray 
                 180/165 
               
               
                 6,793,029 
                 September 2004 
                 Ching 
                  60/413 
               
               
                 6,834,737 
                 December 2004 
                 Boxham 
                 180/165 
               
               
                 6,871,599 
                 March 2005 
                 Okuno 
                 105/238.1 
               
               
                 7,100,723 
                 September 2006 
                 Roethler 
                 180/165 
               
               
                 7,146,266 
                 December 2006 
                 Teslak 
                 701/69 
               
               
                 7,147,078 
                 December 2006 
                 Teslak 
                 180/305 
               
               
                 7,147,239 
                 December 2006 
                 Teslak 
                 280/306 
               
               
                 7,232,192 
                 June 2007 
                 Teslak 
                 303/152 
               
               
                 7,263,424 
                 August 2007 
                 Motoyama 
                 701/69 
               
               
                 7,273,122 
                 September 2007 
                 Rose 
                 180/165 
               
               
                 7,311,163 
                 December 2007 
                 Oliver 
                 180/165 
               
               
                 7,401,464 
                 July 2008 
                 Yoshino 
                  60/414 
               
               
                 7,409,826 
                 August 2008 
                 Epshteyn 
                  60/414 
               
               
                 7,415,823 
                 August 2008 
                 Iwaki 
                  60/487 
               
               
                 7,419,025 
                 September 2008 
                 Ishii 
                 180/242 
               
               
                 7,426,975 
                 September 2008 
                 Toyota 
                 180/165 
               
               
                 7,444,809 
                 November 2008 
                 Smith 
                  60/413 
               
               
                 2004/0182632 
                 September 2004 
                 Hasegawa 
                 180/307 
               
               
                 2007/0227802 
                 October 2007 
                 O&#39;Brien II 
                 180/307 
               
               
                 2008/0093152 
                 April 2008 
                 Gray 
                 180/307 
               
               
                   
               
            
           
         
       
     
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a series hybrid hydraulic drive system than can be applied with advantage to all terrestrial vehicles, including Industrial, commercial and military applications and eventually to passenger vehicles. The prime mover is used to its maximum capacity when running, and reloading of the accumulator occurs when braking and/or when the prime mover is running. 
     2. Description of Prior Art 
     Hybrid Hydraulic—regenerative-drive systems are known and have been applied to motor vehicles in the past. Parallel hydraulic systems are available and have been successful in getting the braking energy back to the accumulator for future use to accelerate the vehicle with acceptable energy savings. 
     The parallel hydraulic system is used as an add-on on vehicles and does not solve the full energy consumption issue of those vehicles. 
     The series hybrid hydraulic system goes beyond the parallel system, but lacks a good and precise flow control-speed-and has not solved, at low cost, the recharge of the accumulator using the extra power of the prime mover when available. 
     Both solutions have a very large handicap: steel accumulators weigh more than 50 times the weight of a lead-acid battery per unit of stored energy. When fiber made accumulators are used, the weight differential is still 12 to 1, but the price skyrockets. Hence all accumulators used for present hybrid hydraulic applications are quite small and usable only for short cycles, mainly for brake energy recuperation. 
     This issue does not allow for those systems to stop the engine when the accumulator is full, as the vehicle will only run for several seconds with the energy content of the accumulator. The present hydraulics are not prepared to allow for this operating mode. 
     The intention of this invention is to overcome the limitations of the prior art by using a simpler and less expensive system, as well being able to dramatically increase the efficiency of all terrestrials vehicles and cut substantially their emissions. 
     BRIEF SUMMARY OF THE INVENTION 
     A hybrid hydraulic system whose objective is to change the economic and technical obstacles confronting hydraulics and its use in terrestrial vehicles, adding benefits not available with the prior art. 
     The use of the accumulator of a hydraulic system as the main chassis of the vehicle overcomes one of the major issues for the implementation of hydraulics, the large weight per unit of stored energy. At the same time this development allows for much larger accumulators, as the accumulator weight is no longer an issue. This new available dimension allows for periods of operation without the prime mover running, saving a large portion of fuel and emissions, as engines and electric motors consume unloaded about 40% of the maximum consumption or current in the case of the electric motors. 
     When the prime mover is running, it will do so at the maximum torque with the proper rpm, it&#39;s most efficient point. If the operation does not need fully this power, the secondary pump will be reloading the accumulator with that available energy. The hydraulic motors will do the same when braking. The prime mover then, when running, will do so only at its optimum efficiency almost all the time. 
     When more torque is needed at the wheels, mainly for acceleration, the accumulator flow will open to the inlet of the power integrator, helping the prime mover to accelerate the vehicle. Of course, the consequence of this arrangement enables the use of smaller prime movers for the same weight and acceleration vehicles. If the pressure coming from the accumulator is too high, the secondary pump will then send the extra energy from the prime mover back to the accumulator. In some cases, we could have several settings for the speed of the prime mover: let&#39;s say urban traffic (low), freeway (middle) and mountain (faster). 
     The coordination of the operation of the system is done with computer and copyrighted software. One version of the controls allows for the use of one pedal or joystick to control speed, direction, acceleration and braking and with a joystick one can add steering, for a vehicle much simpler to control and much safer to operate. The infinite automatic transmission allows for an even better efficiency and lower emissions. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Sheet  1 ,  FIG. 1 : Proposed version of a complete hydraulic schematics, including the accumulator. Some less important devices are not shown. 
       Sheet  2 ,  FIG. 2 : Side view of a commercial Van, using the new arrangement as one example of the multiple applications, for clarification purposes. 
       Sheet  2 ,  FIG. 3 : Top view of same 
       Sheet  2 ,  FIG. 4 : Cutaway AA from  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The preferred embodiment of the present invention is contained in  FIG. 1 .  FIGS. 2 ,  3  and  4  there are just a description of a vehicle sample application of the preferred embodiment of the system on a commercial Van, UPS type. 
       FIG. 1  depicts the preferred embodiment of the hydraulic circuit, indicating schematically an accumulator  1 , the gas container, which at the same time, is the chassis of the vehicle. The oil/gas accumulator  2  could be separated from accumulators or could be installed inside accumulator  1 . 
     The prime mover  10  is connected via a unidirectional coupling  26  to a special unidirectional variable power integrator  11  and in the same shaft, to a unidirectional variable flow pump  12 . This unidirectional coupling is required to allow for the operation of the system when the prime mover is not running. Pump  11  is controlled by servo valve  9  and pump  12  is controlled by servo valve  8 . Both servo valves receive the proper signals from the controller  27 . The accumulator  2  has an electronic oil level indicator that signals the amount of oil in the accumulator  2  to the controller  27 . If the amount of oil is large, the signal to start the system will not launch the prime mover  10 . If the signal indicates a low amount of oil in the accumulator  2 , the prime mover will automatically be started. 
     Once the prime mover  10  is running, power integrator  11  and pump  12  will have zero flow initially. Pump  12  will flow immediately after, charging the accumulator with the available torque from prime mover  10 , via check valve  6 , taking oil from tank  16 . Pump  11 , once it receives a signal to go to a certain flow, will take oil from tank  16 , via check valve  17  and send oil to the hydraulic motors  14 (and  15  if so built) via flowmeter  35 , check valve  40 , solenoid valve  13 (only one version shown) and controlling block  18 . The block  18  will have functions like relief valves, differential control effects, flow sharing, etc. The flow will be the same independent of the pressure. There are two anticavitation valves  19  than could be part of block  18  that go to tank  16 . Pilot line  41  goes to a pilot operated three way, two position valve  4 . When the pressure on line  41  reaches a certain value, valve  4  will open the output of the hydraulic motors to tank  16 . On a generating mode, valve  4  sends the output flow of the motors  14  (and motors  15 ) via check valve  25  and valve  42  to the accumulator  2 . If the accumulator  2  reaches a certain pressure, oil is discharged back to tank via relief valve  7  or to the inlet of the pump  11 . Valve  42  is just a service valve that isolates the accumulator for safety purposes. The safety and/or auxiliary brakes are not represented here, 
     If the output pressure of pump  11  reaches a certain threshold, a pilot line goes thru solenoid valve  36  (two way, two position) to pilot valve  20 —three way, two position valve. The output of valve  20  goes through solenoid valve  33 —three way, two position valve—and controlled orifice  39  to pilot open check valve  5 . This action connects the high pressure accumulator to the inlet of power integrator  11 , to allow for an elevated pressure at the output, obtaining higher accelerations of the vehicle with a much smaller engine. The accumulator flow is the main output flow of power integrator  11  and is controlled but said device  11 . Any over speed of the prime mover—known via speed sensor  31 —makes pump  12  send the extra energy back to the accumulator and in so doing, controlling over speed. 
     When the prime mover is not running because enough energy is stored in the accumulator, we will describe the new running mode: Solenoid valve  36  is energized, closing the pilot line to the pilot operated valve  20 . Solenoid valve  33 —three way, two position valve—is energized opening the accumulator  2  via check valve  5 , to the inlet of power integrator  11 . The speed of the vehicle—meaning the output flow of power integrator  11 —will be controlled by the swash plate position of said power integrator  11  and same for pump  12 . 
     Pedal  29  or Joystick  34 , command a position sensor  30  that signals to the controller what speed is the one desired, and what acceleration or braking rate is required. Internal controls limit both the acceleration and braking or deceleration rate to a given maximum. Switch  38  is a one-off switch to allow for reverse operation when needed. Both the pedal  29  and Joystick  34  go to zero output when released. If, at that point, prime mover  10  is running, it will continue running only until the accumulator  2  is full, loading it via pump  12  and servo control  8 . In that condition, power integrator  11  is not creating any output flow; hence the vehicle is at a standstill. If the Joystick  34  is supplied with an auxiliary position sensor for lateral movement, then we have a Joystick able to additionally control steering. This is not applicable to vehicles running on rails, but all the other functions are. Several pressure transducers  32  allow for the controller to know the instantaneous pressure in several part of the hydraulic circuit, and react properly for the operation and safety of the vehicle. 
     Some auxiliary hydraulic functions could be described here. Charge pump  23  is a low flow, low pressure pump powered by small electric motor  22 . Charge pump  23  could also be powered by main shaft of prime mover, mounted after pump  12 . Suction filter  24 , coming from tank  16 , gets the flow to the inlet of pump  23 , output of pump  23 , goes to filter  18 , relief valve  21 , cooler  20 , back to tank  16 . 
     We are now on sheet  2  with  FIGS. 2 ,  3  and  4 .  FIG. 2  is a depiction of a side view of a commercial Van, type UPS. One can see the position of the accumulator  1  as the chassis for the vehicle. Wheels  3  are also depicted, with larger diameters than the classical Vans. One can also see the door or doorway  7 . 
       FIG. 3  is a top view of the Van. You can see again the accumulator  1 , and the wheels  3 . The oil accumulator  2  is inside the main accumulator  1 . Independent hydraulic motors  14  propel wheels  3  via universal joints  5 . Suspension consist on leveling supports  13 , rotating in a vertical plane, pivoting on support  14 . Both pivots are connected via a torsion bar  6 , and the suspension  7  is common to both wheels through the torsion bar. For a four wheel drive system, motors  15  are shown for the front wheels and suspension  7 A is also shown. The power unit  10  consists of the prime mover and all Hydraulics as well as all mechatronics involved. The hydraulic tank or reservoir  11  is indicated in its position. The driver seat  8  and assistant or trainee seat  9  are sketched on  FIG. 3 . Gas tank  17 , or CNG bottles  17  are also provisionally located on  FIG. 3 . 
     The  FIG. 4  is a cutaway AA of  FIG. 2 , to help understand better the sample design. We can see the structural support  16 , that hold pivot  14 , attached to chassis  1 , as well as torsion bar  6  and universal joints  5 .