GB2373230A

GB2373230A - A vehicle hydraulic braking and energy recovery system

Info

Publication number: GB2373230A
Application number: GB0210577A
Authority: GB
Inventors: Alexander Orestovich Monfor; Philip Alexandrovich Monfor
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-01-21
Filing date: 2002-05-09
Publication date: 2002-09-18
Anticipated expiration: 2022-05-09
Also published as: GB0210577D0; GB0201330D0; GB2373230B; GB0212129D0

Abstract

A hydraulic braking energy recovery system comprises a hub 1 consisting of two halves fastened to a shaft 13 and rotating with it. An elliptic disc 2 consisting of two halves is stationary fixed to a vehicle frame 17 by struts 12 at one end with the hub 1 rotating on bearings round the other end. With rotation of the hub 1 around the disc 2 a pair of seal shutters 3 and 4 create an expansion chamber 14 and a compression chamber 15 filled with a fluid. The chambers are connected to an accumulation tank 30 and to an expansion tank 31 by fluid injection channels 10, fluid return channels 11, fluid injection pipes and fluid return pipes. At braking mode the fluid is pumped to an accumulation tank compressing a gas above the fluid and at acceleration mode the fluid drives the hub 1.

Description

Hydraulic braking energy converter The invention relates to a hydraulic braking energy recovery system for vehicles.

It may be used to convert kinetic energy of a moving vehicle (railcar, tram, lorry, bus, car) usually lost at braking into hydraulic power to accelerate the vehicle later.

The known hydraulic braking energy recovery systems are usually very complicated devices that can only be built in on a vehicle at its manufacturing. The technology developed by Ford and known as Hydraulic Launch Assist is a good example.

The purpose of this invention is to provide a simple hydraulic converter, which may be installed on an existing vehicle.

In accordance with one embodiment of this invention, a hydraulic braking energy converter is provided comprising a hub mountable on a shaft designed as a drum of a rectangular peripheral cross section and consisting of two halves, a disc of elliptic shape consisting of two halves stationary fixed to a vehicle frame at one end and with the hub rotating on bearings around the other end while two points of the disc are in continuous seal contact with the hub, one pair of seal shutters which may travel within slots located at opposite sides of the hub to close the space between the hub and the disc, fluid injection channels and fluid return channels in the disc that provide fluid circulation within the hub, spring biased sealing sliding vanes and sealing sliding rings which seal gaps between the hub, the disc and the shutters in the points of their contact, an accumulation tank and an expansion tank which are connected to the hub by fluid injection pipes and fluid return pipes, shutter locks to lock the shutters at outward position and control valves.

A preferred embodiment of the converter as mounted on a railway car will now be described with reference to the accompanying drawings in which: Figure 1 shows a transversal vertical cross section of the converter with the shutters in the most inward positions.

Figure 2 is a central horizontal cross section of the converter with the shutters in the most inward positions.

Figure 3 is a longitudinal vertical cross section of the converter showing details of the fluid injection channels and the fluid return channels.

Figure 4 is similar to Fig. 2 but with one shutter depicted in details.

Figure 5 is a general layout of the converter.

As shown in Fig. 1, the converter has the hub 1 with the shape of a drum with rectangular cross section. The hub 1 has two shutters-shutter 3 and shutter 4-that are located at opposite sides of the hub 1 and may travel within slots assisted by the shutter springs 5. The hub 1 that is sitting fixed to the shaft 13 may rotate around that end of the disc 2 that is fastened to the vehicle frame 17 by the struts 12. To allow the hub 1 to be mounted on the shaft 13, the hub 1 is made of two halves-top one and bottom one-fastened together by the fixing bolts 6. To allow the disc 2 to be mounted on the shaft 13, the disc 2 is made of two halves-top one and bottom one-fastened together by the bottom fixing studs of the struts 12. The struts 12 allow the disc 2 and the hub 1 to travel up and down with vertical movements of the shaft 13, which is suspended to the vehicle frame 17 as a part of the wheel bogie.

I I.- ell. One end of the disc 2 of an elliptic shape and with its cross section similar to that of the hub 1 IS located within the hub I with its two points in continuous seal contact itch the hub 1 and with two other points being in continuous seal contact with the shutter 3 ar 4. The shutters 3 and 4 slide on the rollers 7, which are lubricated to ensure smooth movement For good contact with changing profile of the disc 2 the shutters 3 and 4 are provided with the transversal sealing sliding vanes of the shutter 9. The disc 2 has two of the transversal sealing sliding vanes 8 and other sealing sliding vanes for sealing transversal and radial gaps between the disc 2 and the hub 1. The transversal sealing sliding vanes 8 always separate the expansion chambers 14 from the compression chambers 15. The disc 2 has the sealing sliding rings 19 to seal side inner gaps between the disc 2 and the hub 1. Inside the disc 2 the fluid injection channels 10 and the fluid return channels 11 are drilled to allow the fluid to circulate between the expansion chambers 14, the compression chambers 15 and outside the disc 2.

The shutter locks 16 are located inside the shutters 3 and 4 to allow the shutters to be locked in the most outward position in order to make the disc 2 rotate free at an idle mode. The solenoids 27 if energized draw the shutter locks 16 inside at the first outward movement of the shutters 3 and 4 thus locking the shutters 3 and 4 in the most outward position. With the solenoids 27 deenergized, the shutter locks 16 return to their original positions thus releasing the shutters 3 and 4. Voltage in the solenoids 27 is generated when they cross stationary magnets on the vehicle frame 17 (not shown). The solenoids 27 are operated by remote infrared controls located on the vehicle frame (not shown).

Further details of the converter are shown in Fig. 2. The shutters 3 and 4 are in their most inward position touching the disc 2 in two pints. The rollers 7 are provided on the side surfaces of the shutters 3 and 4 to ensure smooth movement of the shutters 3 and 4 under pressure conditions.

The bearings 18 support the hub 1 on the disc 2. The transversal sealing sliding vanes of the shutters 9 seal the gap of the shutters 3 and 4 with the disc 2 while the sealing sliding rings 19 seal the gap between the side surface of the hub 1 and the side surface of the disc 2.

Fig. 3 further illustrates positions of the fluid injection channels 10 and the fluid return channels 11. The fluid enters the disc 2 through its face at two opposite points and goes to the expansion chambers via the fluid injection channels 10. The fluid leaves the disc 2 through the fluid return channels 11 at two opposite points at its face. The hub 1 is fixed to the shaft 13 by the fixing bolts 6. The struts 12 keep the disc 2 suspended over the shaft 13 and at the same time fasten two halves of the disc 2 together. The transversal sealing sliding vanes 8 and the radial sealing sliding vanes 20 seal the gap between the disc 2 and the hub 1.

Detailed view of one shutter and the sealing sliding vanes arrangements is presented in Fig. 4 showing a part of the cross section B-B (see Fig. 2) but at the moment when the long axis of the disc 2 is horizontal and it crosses the plane of the shutters (while in Fig. 1 this axis is vertical). At this moment all the sealing sliding vanes are in the same plane and can be easily depicted. The shutter 4 is kept in continuous seal contact with the disc 2 by the shutter springs 5.

As the shutters operate in closed slots, the pressure equalizing channels 23 are provided to even up pressures on the both sides of the shutter while it travels up and down. The rollers 7 ensure easy displacement of the shutter 4 within the hub 1. (The same rollers arrangements apply to the rollers 7 depicted in Fig. 1 and Fig. 2). The transversal sealing sliding vane of the shutter 9 is located in a slot of the shutter 4 and is biased by a spring to secure a good seal contact with its counterpart (at this time-with the transversal sealing sliding vane 8 of the disc 2. ) A detailed cross section E-E of the sealing sliding vanes is presented in the bottom right comer. The radial sealing sliding vane of the shutter 21 is located in a slot of the shutter 4 and is biased by a spring to secure a good seal contact with its counterpart (at this time-with the radial sealing sliding vane 20 of the disc 2). A detailed cross section D-D of these vanes in their contact is presented in the bottom right comer. The radial sealing sliding vanes of the shutter 21 may travel up and down inside the shutter 4 with rotation of the disc 2 and are biased by other springs to keep them in continuous contact with the sealing sliding rings 19. The sealing sliding rings 19 close the gap between the outer side surface of the disc 2 and the inner side surface of the hub 1. All the sealing sliding vanes, the sealing sliding rings and the rollers 7 are interconnected by lubrication channels 22 filled with lubrication oil which provides lubrication of all the sealing sliding vanes and rings including those located on the disc 2 (the transversal sealing sliding vanes 8 and the radial sealing sliding vanes 20) which receive a portion of the lubrication oil each time the disc 2 is in the position shown in Fig. 4.

Fig. 5 is a general layout of the hydraulic braking energy converter. The fluid injection channels 10 and the fluid return channels 11 of the disc 2 are connected to two tanks-the accumulation tank 30 and the expansion tank 31-via the fluid injection pipes 28 and the fluid return pipes 29 correspondently. The pipes are made flexible to allow suspension of the vehicle frame 17 and the struts 12 to move. The accumulation tank 30 accumulates the fluid from the disc 2 at braking mode and discharges it back to the disc 2 at acceleration mode. The accumulation tank 30 has a spare volume above the fluid level that is filled with a gas. The fluid compresses the gas at braking mode creating a pressure A P. The expansion tank 31 holds an excess of the fluid circulating through the converter at different modes. The expansion tank 31 has the air hole 24 to keep its internal pressure ambient. The expansion valve 25, the suction valve 26, the charge valve 32 and the drive valve 33 are used to open or close the fluid injection pipes 28 and the fluid return pipes 29 in order to control operation of the converter.

The converter works in the following way.

In idle mode when the converter does not operate, the solenoids 27 are in switched on mode, the shutter locks 16 are drawn inside the solenoids 27 and the shutters 3 and 4 are locked in their most outward position thus allowing the hub 1 to rotate free around the disc 2. There is no flow of the fluid through the system and pressure in the accumulation tank 30 and the expansion tank 31 is ambient.

In order to initiate braking mode, the solenoids 27 are switched off by a remote control, the shutter locks 16 are released thus releasing the shutters 3 and 4. The converter is now in the position shown in Fig. 1. Rotating anticlockwise, the shutters 3 and 4 push the fluid from the compression chambers 15 into the fluid return channels 11 and at the same time suck the fluid from the fluid injection channels 10 into the expansion chambers 14. The fluid further goes via the fluid return pipes 29 to the accumulation tank 30, as it shown in Fig. 5. With the charge valve 32 and the suction valve 26 open and the expansion valve 25 and the drive valve 33 closed, the fluid is sucked from the expansion tank 31, circulates through the space between the hub 1 and the disc 2 and accumulates in the accumulation tank 30. The pressure A P of the gas in the accumulation tank 30 is rising thus providing braking effect for the vehicle.

The converter is not designed for a fine braking or controlled braking, which is needed at usual driving conditions, this is why usual friction brakes are still needed on the vehicle to used by the end of the braking mode.

By the end of the braking mode the charge valve 32 and the suction valve 26 are closed. As a result of the braking mode some amount of kinetic energy of the vehicle is converted to potential energy of gas pressure A P and is stored in the accumulation tank 30.

In order to initiate acceleration mode, the drive valve 33 and the expansion valve 25 are open and the fluid under the pressure A P comes to the expansion chambers 14 via the fluid injection pipes 28 and the fluid injection channels 10. The fluid creates the pressure A P in the expansion chambers 14 and a pressure differential between the expansion chambers 14 and the compression chambers 15 will develop an anticlockwise torque applied to the hub 1. The torque is equal to the area of the shutter exposed to the fluid, multiplied by 2, multiplied by the pressure differential between the expansion chambers 14 and the compression chambers 15 and multiplied by the distance between the central point of the above area and the axis of the shaft 13. The hub 1 starts rotating anticlockwise.

The fluid discharges from the accumulation tank 30 and goes through the fluid injection pipes 28 and via the fluid injection channels 10 to work in the expansion chambers 14 rotating the hub 1.

It is then pushed off the compression chambers 15, goes through the fluid return channels 11 and via the fluid return pipes 29 and comes to the expansion tank 31. With an ambient pressure in the expansion tank 31, the fluid level will rise till the end of the acceleration mode. At that time the fluid in the both tanks is at ambient pressure.

This is the way in which the converter converts kinetic energy of the vehicle to potential energy of the fluid at braking mode and converts the accumulated potential energy of the fluid to kinetic energy of the vehicle at acceleration mode.

There are several issues, which may be seen as potential disadvantages of the proposed converter design. The first one is impedance to the wheel rotation created by the converter at idle mode.

However, with the shutters 3 and 4 in the locked position the impedance created by the hub 1 rotating against the fluid will be rather low to compare with inertia of the wheels and the vehicle.

Another potential disadvantage of the converter may seemed to be possible internal leakage of the seals at high pressures that is typical for lobe pumps and vane pumps. However, this problem is not crucial for this design of the converter because the pressure depends on the dimensions of the compression chambers 15 which may be chosen as to create a moderate internal pressure.

The design of the seals is even simpler than that of compression rings and lubrication rings in a usual piston-cylinder combination.

Still another issue is reliability and life of the sealing sliding vanes and rings that is one of the major problems for the Wankel engine. This issue is also not crucial for this design as the seals operate in liquid medium of the fluid and the fluid may be chosen based on this criterion, e. g. a lubrication oil.

A further issue is centrifugal forces, which at high RPM may prevent the shutters from moving inward. This issue is again not crucial for this particular application, as it will only mean that the converter will brake more efficiently at low RPM and less efficiently at high RPM. As the converter must be accompanied by a usual friction braking system, it will only affect the rate at which the pressure A P changes.

A final issue may be a problem to keep the gap between the shaft 13 and the disc 2 with suspension operating at high amplitudes. This problem may be avoided by fixing the converter to non-suspended parts of the vehicle, e. g. to the wheel bogie. References 1 Hub 2 Disc 3 Shutter 1 4 Shutter 2 5 Shutter spring 6 Fixing bolts 7 Rollers 8 Transversal sealing sliding vane 9 Transversal sealing sliding vane of the shutter 10 Fluid injection channel 11 Fluid return channels 12 Strut 13 Shaft 14 Expansion chamber 15 Compression chamber 16 Shutter lock 17 Vehicle frame 18 Bearings 19 Sealing sliding ring 20 Radial sealing sliding vane 21 Radial sealing sliding vane of the shutter 22 Lubrication channels 23 Pressure equalising channels 24 Air hole 25 Expansion valve 26 Suction valve 27 Solenoid 28 Fluid injection pipes 29 Fluid return pipes 30 Accumulation tank 31 Expansion tank 32 Charge valve 33 Drive valve

Claims

CLAIM A hydraulic braking energy converter comprising a hub mountable on a shaft designed as a drum of a rectangular peripheral cross section and consisting of two halves, a disc of elliptic shape consisting of two halves stationary fixed to a vehicle frame at one end and with the hub rotating on bearings around the other end while two points of the disc are in continuous seal contact with the hub, one pair of seal shutters which may travel within slots located at opposite sides of the hub to close the space between the hub and the disc, fluid injection channels and fluid return channels in the disc that provide fluid circulation within the hub, spring biased sealing sliding vanes and sealing sliding rings which seal gaps between the hub, the disc and the shutters in the points of their contact, an accumulation tank and an expansion tank which are connected to the hub by fluid injection pipes and fluid return pipes, shutter locks to lock the shutters at outward position and control valves.