AU729976B1

AU729976B1 - Improved hydraulic engine

Info

Publication number: AU729976B1
Application number: AU42580/00A
Authority: AU
Inventors: Michael Kulow
Original assignee: Kulow Lesley Jane
Current assignee: Kulow Lesley Jane
Priority date: 1999-06-21
Filing date: 2000-06-21
Publication date: 2001-02-15
Anticipated expiration: 2020-06-21

Description

50589 GEH:HM P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: MICHAEL KULOW AND LESLEY JANE KULOW Actual Inventor: MICHAEL KULOW Address for Service: COLLISON CO., 117 King William Street, Adelaide, S.A. 5000 Invention Title: IMPROVED HYDRAULIC ENGINE The following statement is a full description of this invention, including the best method of performing it known to us: This invention relates to a hydraulic or pneumatic motor or engine.

Hydraulic or pneumatic motors are well known and commonly used in many applications where rotary motion is required. These motors are of the rotary type, and hydraulic motors are predominantly of the intermeshing gear positive pressure type of motor. Also pneumatic motors are of the turbine type with the air or steam acting against blades on a rotor. These rotary motors usually operate at high speed and thus there is a continuous flow of fluid through the motor resulting in a considerable flow of fluid being required. In the instance of a hydraulic motor this can result in the heating of the hydraulic oil being circulated through the pump, motor and reservoir while with a pneumatic motor the air is exhausted to atmosphere with the requirement that the air compressor has to compress sufficient air at the required pressure.

In addition reciprocating or linear motion is produced by hydraulic or pneumatic rams, and again a large quantity of fluid is required during each stroke of the hydraulic ram.

In our earlier Patent No AU668662 there is described a rotary motor which incorporates a short stroke motor acting on a profile on an output shaft. That motor eliminates the conventional crank and connecting rod by the provision of a large diameter piston with very short stroke acting through a roller or the like directly on a profile on the output shaft.

However piston and cylinder arrangements are subject to frictional resistance during movement of the piston and its sealing rings, wear thus occurring and possible leakage. Also if a non-lubricating fluid drives the piston, such as compressed air or other compressed gasses such as CO2, lubrication must be provided for the piston. This can contaminate the exhausted gas and some means must be provided for providing the adequate lubrication.

It is an object of this invention to provide an hydraulic or pneumatic motor which will overcome one or more of the above disadvantages.

It is a further object of the invention to provide a motor which efficiently converts hydraulic or pneumatic fluid pressure into rotary motion with a reduced flow of hydraulic of pneumatic fluid.

It is a further object of the invention to provide an hydraulic or pneumatic motor in which a large force is obtained from the fluid by a movable member with minimal movement or stroke to be applied to a rotary member.

BRIEF DESCRIPTION OF THE INVENTION Thus in order to achieve one or more of the above objects there is provided according to the invention an hydraulic or pneumatic motor or engine, said engine having a chamber, a diaphragm mounted in said chamber, means to supply pressurised fluid and exhaust said fluid from a first side of said diaphragm, a thrust plate mounted on the second side of said diaphragm, and means to convert the movement of said thrust plate into rotary motion.

In a preferred form of the invention the thrust plate is connected to a push rod and linkage mechanism to convert reciprocatory motion into rotary motion.

In a further preferred form of the invention the thrust plate is connected to a push rod applying its motion to a profile on an output shaft.

In a still further preferred form of the invention there is provided a roller between the push rod and the profile on the output shaft.

In a further form of the invention there is provided a multi-chamber hydraulic or pneumatic motor including an output shaft, a profile on said output shaft, a plurality of chambers equally spaced around said output shaft, a diaphragm in each of said chambers, means to sequentially supply and exhaust fluid under pressure to one side of the respective diaphragms in each of said respective chambers, a thrust plate on the second side of each of said diaphragms, and friction reducing means positioned between each respective thrust plate and the profile on the output shaft.

Preferably the friction reducing means are a roller positioned between each respective thrust plate and the profile on the output shaft.

Also it is preferred that the friction reducing means is a ball bearing positioned on the profile, the outer race of the ball bearing engaging each of the thrust plates.

Preferably the profile is circular in cross section and positioned eccentrically on the output shaft.

It is to be noted that while reference is made to an hydraulic or pneumatic operable by hydraulic fluid or a compressed gas, it is to be noted that the motor can also include operation by steam, particularly low temperature steam with the diaphragm being constructed of a material or materials suitable for the purpose.

BRIEF DESCRIPTION OF THE DRAWINGS In order to more fully describe the invention reference will now be made to the accompanying drawings showing various embodiments of the invention in which Figure 1 illustrates one form of he invention, Figure 2 shows a further form of the invention, Figure 3 shows a multi-diaphragm motor, and Figure 4 shows a further form of a multicylinder motor.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring firstly to Figure 1, the motor one comprises a casing 2 to which a head 3 is attached by bolts, the edge 4 of the diaphragm 5 being clamped between the head and the casing. The head 3 has an inlet valve 6 and an outlet valve 7, these having hydraulic lines connected thereto (not shown), the valves being operated in this embodiment by linkage actuated by a cam or cams on the crankshaft 17.

Within the casing there is positioned a thrust plate 8 connected to a pushrod 9 slidably mounted in a sleeve-like portion 10 of the casing 2. The thrust plate is in contact with the rear side of the diaphragm and thus moves with the diaphragm. The diaphragm is thus subject to the hydraulic pressure and moves under the influence of the hydraulic pressure, this movement being transmitted to the thrust plate and the pushrod. The diaphragm has minimal movement and thus the push rod has only a short stroke.

This movement of the pushrod is amplified by a linkage mechanism to transfer the movement to a flywheel 1. A beam 12 is pivoted by a pivot axle 13, the beam having an arm 14 to engage the end of the push rod 9, the other end of the beam 12 pivoted to a connecting rod 15 which in turn is pivoted to a crank 16 on crankshaft 17 driving flywheel 11. Thus it will be seen that due to the relative proportions of the length of the arm 14 and the beam 12, the small movement of the pushrod is amplified to turn the flywheel 11.

STumrning now to Figure 2 there is shown further form of the invention. In this embodiment the pushrod does not operate through a linkage, but is provided with a roller 18 joumaled by axle 119 to the end of the pushrod 9. The main shaft 20 has a cam or profile 21 formed thereon, the profile being preferably circular and off-centre to the axis of the shaft 20. Preferably the hydraulic pressure on the diaphragm is high pressure and thus the force applied by the roller on the eccentric cam profile will turn the main shaft A further embodiment of the invention is shown in Figure 3. This embodiment is a three chamber motor having three separate chambers 22 in the heads 23.

Each chamber 22 is closed by a diaphragm 24 clamped between the head 23 and a casing 25 each of which has a guide 26 in which a ball 27 moves. Each ball 27 is in contact with a plate 28 which is attached to its respective diaphragm 24. The motor has a drive shaft 29 on which a circular profile 30 is formed the profile being eccentric to the main shaft 29. The steel balls 27 thus roll on and engage the profile 30. The degree of eccentricity of the profile on the main shaft determines the stroke or movement of the diaphragms. There is a fluid inlet 31 to each of the chambers, the flow of fluid being controlled by a ported cross flow rotary valve system driven by the main shaft 29.

Figure 4 illustrates a further embodiment of Figure 3. The heads 23 are supported by body 32, the diaphragms 24 being clamped between the body and the heads by bolts 34. In this embodiment there is a roller or ball bearing race 33 positioned on the profile 30, the inner race on the profile and the outer race of the bearing being in contact with the steel thrust plates 28.

For ease of description the bearings supporting the main shaft are not shown, and neither are the control valves and fluid lines, these being within the knowledge of a person skilled in the art.

The shaft is driven by pressure acting on the diaphragm forcing the metal thrust plate to move. The power transmitted by the thrust plate via the linkage, rollers or bearing race is applied to the profile in the form of the circular cam as part of or attached to the main shaft thus causing the shaft to turn.

The profile drive provides for a very short strike, approximately in the examples shown of about 6mm to 6.5mm. The short stroke enables the use of a flexible membrane to contain fluid or gaseous substances under pressure without leakage between the head and thrust plate to reciprocate in accordance with the operation of the inlet and outlet valve or rotary valve. If the engine is a single chamber a flywheel is provided to provide rotation of the shaft during the exhaust stroke. If the motor is a multi chamber engine a flywheel may not be required but may be desirable to smooth out the operation of the motor.

It is to be noted that during the power stroke the thrust plate is pressed into contact with the linkage, rollers or bearing race. However during the exhaust stroke, the resistance to the exhaustion of the fluid will keep the components parts in contact with each other and there will always be a residual amount of fluid in the chamber acting against the diaphragm to maintain all component parts in contact.

The diameter of the diaphragm may be for example 100mm, if a pressure of 7 pascals is applied to the diaphragm a force in the order of h tonne is applied to the profile resulting in rotation of the profile and shaft, and with high torque.

Thus it will be seen that there is provided according to the invention a fluid engine or motor which by virtue of the pressure of fluid acting on a large area of the diaphragm produces a large force with a very limited stroke of the piston rod or thrust plate. The diaphragm is sealed by its edge to the casing or housing, the thrust plate not contacting or being in sealing engagement with any part of the housing or casing, the thrust plate transmitting the forces to the rollers or bearing race or to the linkage. Thus there is no requirement to seal relatively moving parts there being no frictional losses and wear as is common in piston cylinder arrangements.

The fluid to drive the engine or motor can be any fluid, hydraulic fluid, compressed air, compressed CO2 gas, steam, water or any pressurised fluid whether gaseous or liquid.

Although various forms of the inventiorn- have been described in some detail the invention is not to be limited thereto, but can include all variations and modifications falling within the spirit and scope of the appended claims.

Claims

1. A pneumatic or hydraulic motor or engine, said engine having a chamber, a diaphragm mounted in said chamber, means to supply pressurised fluid and exhaust said fluid from a first side of said diaphragm, pressure transmitting means mounted on the second side of said diaphragm, and means to convert the movement of said pressure applying means into rotary motion.

2. A motor as defined in Claim 1 wherein the pressure applying means is a thrust plate.

3. A motor as defined in Claim 1 or Claim 2 wherein exhaust pressure is applied to the diaphragm during the exhaust stroke.

4. A motor as defined in Claim 3 when appended to Claim 2 wherein the thrust plate is connected to a push rod and linkage mechanism to convert the reciprocatory motion of the thrust plate into rotary motion.

A motor as defined in Claim 2 wherein the thrust plate is connected to a push rod applying its motion to a profile on an output shaft to rotate said shaft.

6. A motor as defined in Claim 5 where there is provided a roller between the thrust plate and the profile on the output shaft.

7. A multi chamber pressurised fluid operated motor including an output shaft, a profile on said output shaft, a plurality of chambers equally spaced around said output shaft, a diaphragm in each of said chambers, means to sequentially supply and exhaust fluid under pressure to one side of the respective diaphragms in each of the respective chambers, a thrust plate on the second side of each of said diaphragms, and friction reducing means positioned between each respective thrust plate and the profile on the output shaft.

8. A motor as defined in Claim 7 wherein the friction reducing means are a roller positioned between each respective thrust plate and the profile on the output shaft.

9. A motor as defined in Claim 8 wherein the friction reducing means is a ball or roller bearing positioned on the profile, the outer race of the bearing engaging each of the thrust plates.

A motor as defined in any one of the preceding claims wherein the profile is circular and positioned eccentrically on said output shaft.

11. A motor substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings. Dated this 21st day of June 2000 MICHAEL KULOW AND LESLEY JANE KULOW By their Patent Attorneys COLLISON CO.