US 4,227,587 AGrant
Automotive Drive System
Issue Date:1980-10-14
•15 Claims
•2 Drawing Sheets
Abstract
An internal combustion engine is connected to a fixed displacement pump normally having its inlet connected to a reservoir and its outlet connected to an accumulator. To start the engine, selectively operable valves connect the inlet of the pump to the accumulator and the outlet to the reservoir to drive the pump as a motor to rotate the engine. Also, a fixed displacement motor has an inlet connected by a forward solenoid valve to the accumulator and pump and connected by a brake solenoid valve to the reservoir. The motor also has an outlet connected to the pump and the accumulator by a reverse solenoid valve and connected to the reservoir by a neutral solenoid valve.
Metadata
Assignee
- Vehicle Energy Corporation
Inventor
- Vincent E. Carman
Application Information
Application Number:US 9488278
Filing Date:1978-10-05
Priority Date:1977-02-07
Art Unit:316
Classifications
IPC:
B60K 900
Field of Search:
1806066 B;66 R;305;307;308;165;306417;413;418
Patent Drawings (2 sheets)
Description
Description
This invention relates to an improved automotive drive system and has for an object thereof the provision of a new and improved automotive drive system.
Another object of the invention is to provide an automotive drive system including an internal combustion engine, a pump connected mechanically to the engine and an accumulator normally supplied with liquid under pressure from the pump and adapted to be selectively connected to the inlet of the pump to drive the pump as a motor to start the engine.
A further object of the invention is to provide an automotive drive system including an accumulator, a pump normally driven by an internal combustion engine and adapted to be driven as a motor to start the engine, and a motor adapted to be selectively driven in forward or reverse by the accumulator and the pump, to be driven by wheels to act as a pump and to be connected in a neutral condition to a reservoir.
Another object of the invention is to provide an automotive drive system including a source of hydraulic liquid under pressure and a fixed displacement motor adapted to be selectively connected to the source and a reservoir in forward, reverse, braking or neutral.
In the drawings:
FIG. 1 is a schematic view of an improved automotive drive system forming one embodiment of the invention with a drive pump thereof being used as a starter motor and a drive motor in a neutral condition;
FIG. 2 is a schematic view of the automotive drive system of FIG. 1 in a forward drive condition and drive pump connected as a pump;
FIG. 3 is a schematic view of the automotive drive system of FIG. 1 in a reverse drive condition and drive pump connected as a pump;
FIG. 4 is a schematic view of the automotive drive system of FIG. 1 in a braking condition and drive pump connected as a pump.
An improved automotive drive system forming one specific embodiment of the invention includes a prime mover in the form of an internal combustion engine 10, the speed of which is set to operate at its most efficient engine speed. Usually, this is slightly over one-half the maximum rated RPM. When the vehicle speed reaches approximately one-half the maximum speed of the vehicle, or extra rapid acceleration is needed, the engine 10 will operate at a higher speed. Such speed will be determined by the position of a foot throttle (not shown). The engine has a drive shaft 12 mechanically connected to a fixed displacement hydraulic pump 14 which also can operate as a fixed displacement hydraulic motor. The engine has an ignition circuit 16 activated when a key operated switch 18 and contacts 20 of a pressure responsive switch 22 are closed to connect it to a battery 24. Contacts 26 of the switch 22 are connected in series with normally closed contacts 28 which are opened, when the engine reaches a minimum operating speed, by a known speed responsive device 30 driven by the engine.
The fixed displacement pump 14 also serves as a fixed displacement motor to rotate the engine 10 to start the engine. To start the engine, switches 18, 82 and 120 are closed by the driver, the system being in its neutral condition as is shown in FIG. 1. The contacts 28 are closed since the engine is not running so that solenoids 34 and 35 are energized to open valves 36 and 37. It is assumed that pressure on hydraulic liquid 38 in an accumulator 40 is lower than the desired minimum operating pressure of, for example, 1700 pounds per square inch. The switch 22 is set to energize whenever the pressure drops below a predetermined level, for example, 2,000 PSI, whereby contacts 26 close and current flows through closed contacts 28 and opens valves 36 and 37 by energizing solenoids 34 and 35. The liquid flows from the accumulator 40 through lines 42, 44, 46, 48 and 50, the valve 36 and lines 52 and 54 to port 56 of the pump 14, through the pump 14 (to drive it as a motor), out port 58 of the pump, through lines 60 and 62 of the valve 37 and lines 64, 66, 68 and 70 to a reservoir 72. This drives the pump as a motor to turn the engine to start it. When it has started and reached a low level operating speed, the speed responsive device opens the switch 28. Opening of the switch 28 drops out the solenoids 34 and 35 and the valves 36 and 37 close. The pump 14 now acts as a pump to pump the liquid from the line 54 through lines 60 and 74, a check valve 76 and line 78 to the line 48. A fixed displacement hydraulic motor 100, which serves as the vehicle drive motor and also may operate as a pump, may or may not be turning depending on whether or not the vehicle is in motion when the engine start cycle occurs. If we assume that the vehicle is moving forward, and motor 100 rotating and valves 128 and 90 are both open, the motor will be in a neutral condition and oil from reservoir 72 will flow through valve 128, motor 100 and valve 90 back to the reservoir 72.
Motor 100 has two ports 98 and 102, respectively referred to as the inlet and outlet ports. The inlet port 98 of the motor 100 is connected by a "forward" solenoid valve 88 to the accumulator 40 and by a "brake" solenoid valve 128 to the reservoir 72. The outlet port 102 of the motor 100 is connected by a "reverse" solenoid valve 130 to the accumulator and by a "neutral" solenoid valve 90 to the reservoir.
To drive the automobile forward, the driver closes switch 80 preferably placing the system in the condition shown in FIG. 2, and opens switch 120. Closing the switch 80 causes energization of solenoid 84. Opening switch 120 de-energizes solenoid 124. Thus, valve 88 opens and valve 128 closes. The liquid 38 then is forced from the line 42 or 46 through line 92, the valve 88, lines 94 and 96; port 98 of motor 100; the motor 100; port 102 of the motor 100; lines 104 and 106; the valve 90, and line 108 to the line 66 leading to the pump through a line 107, a check valve 109 and lines 111 and 54 if the engine is running. If the engine is not running, the oil will flow through line 68 to the reservoir 72. The motor is connected to drive axle 110 and drives drive wheels 112 of the automobile in a forward direction.
To drive the automobile in reverse, the driver places the system in the condition thereon shown in FIG. 3 by actuating a switch in the driving compartment and depressing the accelerator. The switches 80 and 82 are open and switches 120 and 122 are closed to energize solenoid windings 124 and 126 to open valves 128 and 130. The liquid 38 pumped from the pump 14 or flow from accumulator 40, then flows from the line 46 through line 140, the valve 130, lines 142 and 104, the motor 100, lines 96 and 144, the valve 128 and line 146.
To brake the automobile, the system is placed by the driver in the condition shown in FIG. 4, by removing his foot from the accelerator. The switch 120 is closed to cause the valve 128 to open. The motor 100 then acts as a pump to pump the liquid 38 from the line 146 through the valve 128, lines 144 and 96; the motor 100; lines 104 and 150; check valve 152 and lines 154, 44 and 42 to the accumulator 40.
To start the engine 10 under a condition in which there is insufficient pressure in the accumulator 40 to start the engine, the driver closes the switch 18 to open the valves 36 and 37 and closes the switch 120. The automobile then is pushed, or coasted downhill, and the motor 100 is in its pumping phase (braking) and pumps the liquid 38 through the valve 152 to the accumulator and the pump 14, which is thereby driven as a motor to turn over the engine and start it. Also, a handpump (not shown) could be used to pump oil from the reservoir into the accumulator.
An adjustable relief valve 160 is provided to prevent the pressure in the accumulator from exceeding a predetermined maximum, for example, 3,200 pounds per square inch. The pressure switch 22 is set to be closed to start the engine 10 whenever the pressure is less than a desired predetermined minimum, for example, 1,700 pounds per square inch. The switch 22 is set to open the contacts 20 and 26 at the upper limit of the desired operating ranges, for example, 2,800 pounds per square inch. The motor 100 then is driven by the accumulator 40 alone, without the engine 10, until the pressure goes below a lower limit of, for example 1,700 pounds per square inch, the switch 22 then closing the contacts 20 and 26.
For starting, using the pump as a starter motor, the the engine 10 is turned over very rapidly as the starter motor is capable of providing as much horsepower as the engine. This rapid starting of the engine eliminates pollutants during the frequent stop/start cycle of the engine.
Claims
What is claimed is:
1. In a wheeled vehicle having an engine for driving the vehicle, a starting system for selectively storing energy normally lost in braking the vehicle and releasing the stored energy to start the engine, said starting system comprising: (a) an accumulator for storing pressurized fluid; (b) a reservoir for storing fluid; (c) hydraulic pump means mechanically coupled to the wheels of said vehicle for being driven by said wheels, said pump means having an inlet and an outlet; (d) first control means for selectively hydraulically connecting the inlet of said pump means to said reservoir and the outlet of said pump means to said accumulator for pumping hydraulic fluid from said reservoir into said accumulator for storage therein under pressure in response to the driving of said pump means by said wheels to brake said vehicle; (e) hydraulic motor means mechanically coupled to said engine for driving and thereby starting said engine, said motor means having an inlet and an outlet; (f) second control means for selectively hydraulically connecting the inlet of said motor means to said accumulator for receiving said hydraulic fluid from said accumulator and the outlet of said motor means to said reservoir to drive said engine for starting; and (g) speed responsive means connected to said engine for determining the speed of rotation thereof, said second control means including valve means responsive to said speed responsive means for stopping the flow of hydraulic fluid from said accumulator to said motor means when the engine has reached a predetermined speed.
2. In a wheeled vehicle having an engine for driving the vehicle, a starting system for selectively storing energy normally lost in braking the vehicle and releasing the stored energy to start the engine, said starting system comprising: (a) an accumulator for storing pressurized fluid; (b) a reservoir for storing fluid; (c) hydraulic pump means mechanically coupled to the wheels of said vehicle for being driven by said wheels, said pump means having an inlet and an outlet; (d) first control means for selectively hydraulically connecting the inlet of said pump means to said reservoir and the outlet of said pump means to said accumulator for pumping hydraulic fluid from said reservoir into said accumulator for storage therein under pressure in response to the driving of said pump means by said wheels to brake said vehicle; (e) hydraulic motor means mechanically coupled to said engine for driving and thereby starting said engine, said motor means having an inlet and an outlet; (f) second control means for selectively hydraulically connecting the inlet of said motor means to said accumulator for receiving said hydraulic fluid from said accumulator and the outlet of said motor means to said reservoir to drive said engine for starting; and (g) pressure responsive means, connected to said accumulator and to said second control means, for preventing the flow of hydraulic fluid from said accumulator to said motor means if the pressure in said accumulator exceeds a predetermined maximum.
3. The starting system of claim 2 wherein said engine includes an ignition system and said pressure responsive means includes means for disabling said ignition system if the pressure in said accumulator exceeds said predetermined maximum.
4. In a wheeled vehicle having an engine for driving the vehicle, a starting system for selectively storing energy normally lost in braking the vehicle and releasing the stored energy to start the engine, said starting system comprising: (a) an accumulator for storing pressurized fluid; (b) a reservoir for storing fluid; (c) hydraulic pump means mechanically coupled to the wheels of said vehicle for being driven by said wheels, said pump means having an inlet and an outlet; (d) first control means for selectively hydraulically connecting the inlet of said pump means to said reservoir and the outlet of said pump means to said accumulator for pumping hydraulic fluid from said reservoir into said accumulator for storage therein under pressure in response to the driving of said pump means by said wheels to brake said vehicle; (e) hydraulic motor means mechanically coupled to said engine for driving and thereby starting said engine, said motor means having an inlet and an outlet; (f) second control means for selectively hydraulically connecting the inlet of said motor means to said accumulator for receiving said hydraulic fluid from said accumulator and the outlet of said motor means to said reservoir to drive said engine for starting; and (g) pressure responsive means, connected to said accumulator and to said second control means, for directing the flow of hydraulic fluid from said accumulator to said motor means in response to a drop in the pressure in said accumulator below a predetermined minimum.
5. The starting system of claim 4 wherein said engine includes an ignition system and said pressure responsive means includes means for turning on said ignition system if the pressure in said accumulator is below said predetermined minimum.
6. In a wheeled vehicle having an engine for driving the vehicle, a starting system for selectively storing energy normally lost in braking the vehicle and releasing the stored energy to start the engine, said starting system comprising: (a) an accumulator for storing pressurized fluid; (b) a reservoir for storing fluid; (c) hydraulic pump means mechanically coupled to the wheels of said vehicle for being driven by said wheels, said pump means having an inlet and an outlet; (d) first control means for selectively hydraulically connecting the inlet of said pump means to said reservoir and the outlet of said pump means to said accumulator for pumping hydraulic fluid from said reservoir into said accumulator for storage therein under pressure in response to the driving of said pump means by said wheels to brake said vehicle; (e) hydraulic motor-pump means mechanically coupled to said engine for selectively either driving and thereby starting said engine or being driven by said engine to pump fluid, said motor-pump means having an inlet and an outlet; (f) first valve means connected to the inlet of said motor-pump means and to said accumulator for controlling fluid flow therebetween; (g) second valve means connected to the outlet of said motor-pump means and to said accumulator for controlling fluid flow therebetween; (h) third valve means connected to the inlet of said motor-pump means and to said reservoir for controlling fluid flow therebetween; (i) fourth valve means connected to the outlet of said motor-pump means and to said reservoir for controlling fluid flow therebetween; and (j) starting control means for selectively operating at least said first and fourth valve means to permit fluid to flow either from said accumulator through said motor-pump means to said reservoir whereby said motor-pump means operates as a motor to drive said engine, or from said reservoir through said motor-pump means to said accumulator whereby said motor-pump means operates as a pump driven by said engine to pressurize said accumulator.
7. The starting system of claim 6 wherein said first and fourth valve means each comprise solenoid-operated valves, and said starting system further comprises electrical circuit means for operating said solenoid-operated valves.
8. In a wheeled vehicle having an engine for driving the vehicle and a system for selectively storing energy normally lost in braking the vehicle and using said energy to drive the vehicle, a drive transmission and engine starting system comprising: (a) an accumulator for storing pressurized fluid; (b) a reservoir for storing fluid; (c) first hydraulic pump means mechanically coupled to the wheels of said vehicle for being driven by said wheels, said pump means having an inlet and an outlet; (d) first control means for selectively hydraulically connecting the inlet of said first pump means to said reservoir and the outlet of said first pump means to said accumulator for pumping hydraulic fluid from said reservoir into said accumulator for storage therein under pressure in response to the driving of said pump means by said wheels to brake said vehicle; (e) first hydraulic motor means mechanically coupled to the wheels of said vehicle for driving said wheels, said motor means having an inlet and an outlet; (f) second control means for selectively connecting the inlet of said motor means to said accumulator for receiving hydraulic fluid under pressure therefrom and the outlet of said motor means to said reservoir to drive said wheels; (g) second hydraulic pump means mechanically coupled to said engine for being driven by said engine, said second pump means having an inlet and an outlet, the inlet of said second pump means being connected to said reservoir and the outlet of said second pump means being connected to said accumulator for pumping fluid from said reservoir into said accumulator for storage therein under pressure in response to the driving of said second pump means by said engine; (h) pressure responsive means connected to said accumulator and to said engine for stopping said engine when the pressure in said accumulator exceeds a predetermined maximum; and (i) pressure responsive means, connected to said accumulator and to said engine, for starting said engine in response to a drop in the pressure in said accumulator below a predetermined minimum.
9. The drive transmission and engine starting system of claim 8 further comprising second hydraulic motor means for driving said engine, said second motor means having an inlet and an outlet, and third control means for selectively connecting the inlet of said second motor means to said accumulator and the outlet of said second motor means to said reservoir to drive said engine for starting, while preventing the exertion of back pressure from said accumulator on said outlet of said second pump means, said pressure responsive means for starting said engine in response to a drop in the pressure n said accumulator below a predetermined minimum being connected to said third control means for actuating said third control means to start said engine.
10. The drive transmission and engine starting system of claim 9 further comprising starter cut off means connected to said engine and to said third control means for stopping the flow of hydraulic fluid from said accumulator to said second motor means when said engine has reached a predetermined state.
11. In a wheeled vehicle having an engine for driving the vehicle, a starting system for selectively storing energy normally lost in braking the vehicle and releasing the stored energy to start the engine, said starting system comprising: (a) an accumulator for storing pressurized fluid; (b) a reservoir for storing fluid; (c) fixed displacement hydraulic pump means mechanically coupled to the wheels of said vehicle for being driven by said wheels, said pump means having an inlet and an outlet; (d) first control means for selectively hydraulically connecting the inlet of said pump means to said reservoir and the outlet of said pump means to said accumulator for pumping hydraulic fluid from said reservoir into said accumulator for storage therein under pressure in response to the driving of said pump means by said wheels to brake said vehicle; (e) fixed displacement hydraulic motor means mechanically coupled to said engine for driving and thereby starting said engine, said motor means having an inlet and an outlet; and (f) second control means for selectively hydraulically connecting the inlet of said motor means to said accumulator for receiving said hydraulic fluid from said accumulator and the outlet of said motor means to said reservoir to drive said engine for starting.
12. The starting system of claim 11 further comprising starter cut off means connected to said motor means and to said second control means for stopping the flow of hydraulic fluid from said accumulator to said motor means when said engine has reached a predetermined state.
13. The starting system of claim 11 wherein said first control means comprises a first direction-control valve connected to said accumulator and to said inlet of said pump means, a second direction-control valve connected to said outlet of said pump means and to said reservoir, a third direction-control valve connected to said reservoir and to said inlet of said pump means, a fourth direction-control valve connected to said outlet of said pump means and to said accumulator, and direction-control means connected to said first, second, third and fourth direction-control valves for selectively actuating them.
14. The starting system of claim 13 wherein said first, second, third and fourth direction-control valves are each solenoid-operated and said direction-control means includes anelectrical circuit for actuating said direction control valves.
15. The starting system of claim 14 further comprising a check valve connected to said outlet of said pump means and to said accumulator to permit fluid to flow from said pump means through said check valve to said accumulator but to prevent fluid flow through said check valve in the opposite direction.
Patent Citations (16)
| Patent | Date | Inventor | Cited By |
|---|---|---|---|
| US732908 | 1903-07-01 | Thomson | |
| US1320485 | 1919-11-01 | Maw et al. | |
| US2240011 | 1941-04-01 | Casey | |
| US3700060 | 1972-10-01 | Keene et al. | |
| US3892283 | 1975-07-01 | Johnson | |
| US3903696 | 1975-09-01 | Carman | |
| US3923115 | 1975-12-01 | Helling | |
| DEX1006732 | 1957-04-01 | ||
| DEX2507006 | 1976-09-01 | ||
| FRX1083808 | 1954-06-01 | ||
| FRX2272859 | 1975-12-01 | ||
| FRX2294874 | 1976-07-01 | ||
| GBX762721 | 1956-12-01 | ||
| GBX955604 | 1964-04-01 | ||
| GBX1029857 | 1966-05-01 | ||
| GBX1032392 | 1966-06-01 |