This disclosure relates to a pneumatic motor with improvements thereto including multiple stacked radial pistons, unitary cylinder cap, a modular valve bushing and a controller for regulating air speed, air supply, motor speed and reading of speed and air supply and torque, depending on load.
Current pneumatic motors (or air motors) include pistons aligned in the same plane. It has been found that pneumatic motors with pistons in the same plane result in the requirement of thrust washers and retainers to allow rotation without interference. Furthermore, current pneumatic motors include valve bushings that are unitary. It has been found that unitary valve bushings result in galling and seizing of the pneumatic motor due to the entry of unwanted particles via the air source into the motor. Furthermore, current pneumatic motors include cylinder covers that are multi-component. It has been found that multi-component cylinder covers result in the build-up of unwanted heat in the motors as well as air loss, reducing the efficiency of the pneumatic motor. Furthermore, current pneumatic motors lack a controller to regulate air speed, motor speed, air supply to the motor as well as reading and transmission of data associated with the pneumatic motor. There is a need for a pneumatic motor with pistons being in different parallel planes. There is also a need for a pneumatic motor with modular valve bushings. There is also a need for a pneumatic motor with a unitary cylinder cap. There is also a need for a pneumatic motor controller.
According to one aspect, there is provided:
a pneumatic motor for rotating an axle comprising:
a housing comprising an air intake port;
an air exhaust port;
at least two cylinders; wherein each cylinder is positioned radially from the axle; in one alternative, each cylinder being in a distinct radial plane from each other;
at least two air channels in communication with each cylinder;
at least two pistons, each piston attached to the axle by a connecting rod, each piston and respective connecting rod being radially aligned, in respect of the axle and in one alternative, in a distinct radial plane from each other, each piston to be received in one of said at least two cylinders; each connecting rod being attached centrally offset in relation to a central axis of said axle;
According to another aspect, there is provided a modular bushing fit onto said axle to regulate communication of said air intake port and said air exhaust port with said at least two air channels in communication with each cylinder;
wherein during a power stroke of one piston or more, said axle allows said air intake port to be in communication with the air channel in communication with said one cylinder allowing air from the air intake port to enter into the cylinder; and during an exhaust stroke of one piston or more, said axle allows said air exhaust post to be in communication with the air channel in communication with said one cylinder allowing air to exit the cylinder through the air exhaust port;
wherein, when one connecting rod and piston are in power stroke, the other connecting rod and piston are in exhaust stroke.
In another alternative, one end of each of said connecting rods are stacked one atop another on said axle, in an axially offset configuration, resulting in each of said connecting rods and each of said pistons connected to said respective connecting rod being in a distinct radial plane, each distinct radial plane being parallel to each other.
In another alternative, each of said connecting rods is stacked one atop another and is separated one from another by a spacer on said axle.
In another alternative, each of said connecting rods stacked one atop another further comprise a bearing on said axle between each of said connecting rods.
In another alternative, said axle further comprises an air intake face and an air exhaust face.
In another alternative, said air intake face and said air exhaust face run along a length of said axle and are opposite each other along the length of said axle.
In another alternative, said pneumatic motor further comprises a modular valve bushing to fit over said axle for allowing communication of air to/from the pneumatic motor, depending on the rotational location of said axle in relation to said modular valve bushing. The modular valve bushing described herein differs from the prior art bushing made of a single piece which has exhibited the following drawbacks including the inability to use a bearing material in the sealing area to eliminate the possibility of galling as well as the opportunity to provide minimal interference to reduce air consumption and leakage. In one alternative, said modular valve bushing comprises an upper component, a lower component and an intermediary component wherein the upper component and lower component are matingly engaged with each other by said intermediary component.
In another alternative, said upper component, lower component and intermediary component are hollow cylinders, each having an outer diameter surface and at least one inner diameter surface.
In another alternative, the outer diameter surface of said intermediary component matingly engages with the inner diameter of said upper component and lower component.
In another alternative said upper component is a hollow cylinder having a top surface, a bottom surface, an outer collar surface and an inner collar surface. In yet another alternative, said upper component further comprises a plurality of air inlet and outlet channels. In one alternative, said air inlet and outlet channels run axially and radially to said hollow cylinder of said upper component. In one alternative, a portion of said channels run axially to said hollow cylinder of said upper component and are air exhaust channels.
In another alternative, said lower component is a hollow cylinder having a top surface, a bottom surface, an outer collar surface and an inner collar surface. In yet another alternative, said lower component further comprises at least one air intake channel running axially to said hollow cylinder of said lower component. In one alternative, said at least one air intake channel running axially to said hollow cylinder of said lower component is situated at an upper portion of said lower component.
In another alternative, said intermediary component is a connecting collar for connecting said upper component with said lower component. In one alternative, said connecting collar further comprises an inner diameter surface and an outer diameter surface.
In another alternative, each of said upper component and lower component further comprise a connecting collar receiving section to each receive an end of said connecting collar top axially connecting the upper component with the lower component forming a cylinder valve bushing for a pneumatic motor. The lower component includes and upper area of a first diameter and a lower are of a second diameter. The second diameter being smaller than the first diameter allowing the connecting collar to be friction fitted within the upper and lower components, preferably causing said connecting collar to be non-rotating when connecting the upper and lower components.
In another alternative, said connecting collar is locked to said modular bushing via a locking pin. In one alternative, said connecting collar is locked to said upper component via a locking pin.
In another alternative, said air inlet channels of said upper component are in fluid communication with said at least one air intake channel of said lower component when said air intake face of said axle is in line with said at least one air intake channel of said lower component, during rotation of said axle.
In another alternative, said air outlet channels of said upper component are in fluid communication with said air exhaust port when said air exhaust face of said axle is in line with said air outlet channels of said upper component, during rotation of said axle. It has been found that the modular bushing, due to the surface characteristics of the connecting collar being softer or less dense than the surface characteristics of the rotating axle prevents foreign or unwanted particulates, that may enter with the air supply to the pneumatic motor, to impact and compromise the surface of the axle by allowing any foreign particulates to be absorbed by the surface of the connecting collar thereby mitigating damage (including seizing of the motor due to a foreign particulate between the connecting collar (intermediary bushing) surface and axle surface) to pneumatic motor parts by foreign particulate material entering the system with the air supply.
According to yet another alternative, there is provided a unitary piston cylinder cap in a pneumatic motor, in one alternative at least two unitary piston cylinder caps in a pneumatic motor, each cylinder cap forming a cylinder, on said pneumatic motor, each cylinder for receiving each of said at least two pistons, eliminating the need for a cylinder sleeve and associated seals thereby reducing the number of parts and mitigating air leakage between a cylinder cap and a cylinder sleeve, the prior art combination cylinder cap and a cylinder sleeve forming a piston cylinder.
In one alternative, said unitary piston cylinder cap further comprises an cylinder cap air channel for communication with said air channel in communication with said cylinder of said pneumatic motor housing for the exchange of air into and out of a space formed by a piston and a cylinder cap, in one alternative, each of said at least two unitary piston cylinder caps further comprise an cylinder cap air channel for communication with said air channel in communication with said cylinder of said pneumatic motor housing for the exchange of air into and out of a space formed by each of said at least two pistons and each of said at least two cylinder caps.
According to yet another alternative, there is provided a pneumatic motor for rotating an axle comprising:
a housing comprising an air intake port;
an air exhaust port;
at least three cylinders; wherein each cylinder is positioned radially from the axle; in one alternative, each cylinder being in a distinct radial plane from each other;
at least two air channels in communication with each cylinder;
at least three pistons, each piston attached to the axle by a connecting rod, each piston and respective connecting rod being radially aligned, and in one alternative, in a distinct radial plane from each other and each connecting rod being stacked in relation to each other, each piston to be received in one of said at least three cylinders; each connecting rod being attached centrally offset in relation to a central axis of said axle;
a modular bushing fit onto said axle to regulate communication of said air intake port and said air exhaust port with said at least two air channels in communication with each cylinder;
wherein during a power stroke of at least one piston, said axle allows said air intake port to be in communication with the air channel in communication with said one cylinder allowing air from the air intake port to enter into the cylinder; and during an exhaust stroke of at least one piston, said axle allows said air exhaust post to be in communication with the air channel in communication with said one cylinder allowing air to exit the cylinder through the air exhaust port;
wherein when one connecting rod and piston are in power stroke, the other connecting rod and piston are in exhaust stroke and the third connecting rod and piston are in between an exhaust stroke and a power stroke.
In one alternative, there is provided at least three unitary piston cylinder caps, each cylinder cap forming a cylinder, on said pneumatic motor, each cylinder for receiving each of said at least three pistons.
In one alternative, each of said at least three unitary piston cylinder caps further comprise an cylinder cap air channel for communication with said air channel in communication with said cylinder of said pneumatic motor housing for the exchange of air into and out of a space formed by each of said at least three pistons and each of said at least three cylinder caps.
In one alternative, each of said at least three unitary piston cylinder caps are in a distinct horizontal plane from each other.
According to yet another alternative, there is provided a pneumatic motor for rotating an axle comprising:
a housing comprising an air intake port;
an air exhaust port;
at least six cylinders; each cylinder being positioned radially from the axle; in one alternative each cylinder being in a distinct radial plane from each other;
at least two air channels in communication with each cylinder;
at least six pistons, each piston attached to the axle by a connecting rod, each piston and respective connecting rod being radially aligned, in respect of the axle and in one alternative, in a distinct radial plane from each other, each piston to be received in one of said at least six cylinders; each connecting rod being attached centrally offset in relation to a central axis of said axle;
a modular bushing fit onto said axle to regulate communication of said air intake port and said air exhaust port with said at least two air channels in communication with each cylinder;
wherein during a power stroke of at least one piston, said axle allows said air intake port to be in communication with the air channel in communication with a cylinder of the piston during a power stroke allowing air from the air intake port to enter into the cylinder; and during an exhaust stroke of at least one piston, said axle allows said air exhaust post to be in communication with the air channel in communication with a cylinder of the piston undergoing an exhaust stroke allowing air to exit the cylinder through the air exhaust port.
In one alternative, there is provided at least six unitary piston cylinder caps, each cylinder cap forming a cylinder, on said pneumatic motor, each cylinder for receiving each of said at least six pistons.
In one alternative, each of said at least six unitary piston cylinder caps further comprise an cylinder cap air channel for communication with said air channel in communication with said cylinder of said pneumatic motor housing for the exchange of air into and out of a space formed by each of said at least six pistons and each of said at least six cylinder caps.
In one alternative, there is provided a tachometer on said pneumatic motor to read rotations per minute of said axle.
In yet another alternative, there is provided a controller, in communication with said tachometer, to regulate air pressure, air flow, air speed and motor speed and torque, depending on the load on said motor.
It was found the intermediary component, in one alternative a collar, is resistant to heat expansion and contraction, and the coefficient of friction of the intermediary component, in one alternative a collar, surface is extremely low and further mitigates galling due to the surface of said intermediary component (in one alternative a collar) being of a material such that the surface absorbs any foreign particles thereby mitigating galling and seizing of said motor. A preferred material being Torlon™, polyvinylidene fluoride, glass filled Teflon™ and combinations thereof. Alternate materials are Teflon™, low density polyethylene, high density polyethylene, ultra high molecular weight (UHMW) Polyethylene, polypropylene, CE grade (canvas phenolic resin—general purpose grade) phenolic laminates, LE grade (cotton phenolic resin—electrical grade) phenolic laminates, nylon and combinations thereof.
It was also determined that the modular bushing results in reduced air consumption (30% to 40%) by the pneumatic motor as compared to a unitary bushing, improving efficiency without compromising performance of the pneumatic motor. We also found the collar (intermediary component) allows for a reduced gap between the inside diameter of the collar against the outside diameter of the rotating shaft resulting in less leakage of air between the space formed by the outside diameter of the rotating shaft and the inside diameter of the collar.
It was also found that the collar mitigates seizing of the shaft against the valve bushing.
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Pneumatic motor 10 includes a vent 101 (which may also serve as a window to the interior of said motor and may be made of a transparent material) centrally located (although it may be offset from center of the motor head cover 103) on an pneumatic motor head cover 103, in this alternative, the pneumatic motor head cover 103 is triangular in shape and has three fastener holes 131 for three fasteners 102 to allow for fastening the pneumatic motor head cover 103 onto the top of motor housing 104. Motor housing 104 includes three fastener holes 133 for alignment of pneumatic motor head cover 103 fastener holes 131. Motor housing 104 is cylindrical in shape with three cylinder ports 134 (only one seen) each for receiving each of the three pistons 114. Each cylinder port 134 is covered by a cylinder cap 60 (See
Motor housing further includes an air supply connector 105 threaded to the air supply port 30 (See
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Unitary cylinder cap 605 includes a motor body wall 607 to facilitate the seating of the cylinder cap 605 onto said motor body. Cylinder cap 605 includes an O-ring seal 606 to seal the air channel (138/115) against the motor body air channel 139.
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The following is an example comparing a pneumatic motor using a prior art unitary bushing versus a modular bushing.
Two pneumatic motors, one with a modular bushing and unitary cylinder caps described herein and one with a one piece prior art bushing were run under the same conditions and air consumption was measured. Pressure was regulated at various levels, rotations per minute (RPM) was kept constant at 100 and maximum torque (in-lb) and air consumption at cubic feet per minute (CFM) was measured.
3 Cylinder Motor with a Modular Bushing and Unitary Cylinder Caps
SUPPLY PRESSURE: 120 P.S.I. (pounds per square inch). These values represent an average of 10-3 cylinder pneumatic motors assembled with a modular 3 piece bushing.
Prio Art 3 Cylinder Motor with a Unitary Bushing and Multicomponent Cylinder Caps
SUPPLY PRESSURE: 120 P.S.I.
These values represent an average of 3-3 cylinder pneumatic motors assembled with a 1 pc bushing.
As can be seen, unexpectedly the air consumption of the same pneumatic motor with a modular bushing used substantially less air in CFM while maintaining the same RPM and very close maximum torque when compared to a unitary bushing.
The following is a calculation of return on investment with a 6 cylinder pneumatic motor described herein having a modular bushing.
1 horsepower (HP) is equal to 746 watts (W) or 0.746 KW (¾ KW)
On average most compressors will produce 4 CFM @ 90 PSI per 1HP Therefore: @ 90 PSI it takes 0.746 KW (¾KW) to produce 4 CFM. 0.746 KW divided by 4 CFM=0.1865 KW for 1 CFM.
Therefore, it takes 0.1865 KW to produce 1 CFM.
Calculation of Cost Savings
Step 1. Calculate the CFM difference with pneumatic motor described herein and a prior art motor using a simple CFM gauge.
Example: Prior art 3 cylinder pneumatic motor: 4.55 CFM pneumatic motor
3 cylinder pneumatic motor (with 3 pc. Bushing): 2.72 CFM. Difference in CFM usage=1.83 CFM.
Step 2. Calculate local electrical supply costs.
For this example we will use $0.10 per kwh (it cost $0.10 to create 1 KW for 1 hour).
Step 3. Take what is known: 0.1865 kw/CFM and multiply it by hrs/day (24) and days/year (365) 0.1865×24×365=1,633.74 KW
Conclusion: It takes 1,633.74 KW to create one CFM for 24 hrs a day for 1 year.
Step 4. Multiply your kw/year value (1,633.74) by your local electricity supply costs ($0.10/kwh)
1,633.74×$0.10=$163.37
Conclusion: It takes $163.37 to create 1 CFM 24 hrs a day for 1 year.
Step 5. Multiply the cost to create 1 CFM/year ($163.37) by the total difference in CFM (1.83) $163.37×5.48=$298.96
Conclusion: The total savings (in compressed air alone) over 1 year when using the pneumatic motor described herein compared to a prior art motor with a unitary bushing is $298.96 per pneumatic motor.
The following provides the difference in operating temperature comparing a prior art pneumatic motor with the pneumatic motor described herein.
Temperature readings were taken near the cylinder cap from a three cylinder pneumatic motor after one hour of run time at ambient room temperature of 65 degrees F.
Pneumatic motors were each ran at 200 RPM
There is a significant decrease in temperature (16-20% lower) during run time when a unitary cylinder cap is used versus the prior art multi-piece cylinder cap
Pneumatic motors were each ran at 800 RPM
There is a significant decrease in temperature (21-29% lower) during run time when a unitary cylinder cap is used versus the prior art multi-piece cylinder cap.
In terms of construction material:
the motor housing may be made of aluminum, zinc, steel, cast iron, stainless steel, nylon, and combinations thereof;
the vent may be made of nylon, acetal, glass filled nylon, low density polyethylene, and combinations thereof;
the head cover may be made of aluminum, zinc, steel, cast iron, stainless steel, nylon, and combinations thereof;
the crank pin may be made of steel, stainless steel, 4140 alloy steel and combinations thereof;
the spacer may be made of steel, stainless steel, nylon, fiber and combinations thereof;
the bearings may be made of steel, stainless steel and combinations thereof;
the piston head may be made of glass filled nylon, acetal and combinations thereof;
the connecting rod may be made of steel, brass, aluminum, Delrin, nylon, glass filled nylon, aluminum filled nylon and combinations thereof;
the wrist pin may be made of steel, stainless, brass, bronze and combinations thereof;
the piston seal may be made of urethane, Buna-N-O-rings, fluoroelastomer, Teflon, UHMW polyethylene and combinations thereof;
the cylinder cap O-ring may be made of Buna, Fluoroelastomer, ethylene propylene diene terpolymer (EPDM rubber), Teflon™, fluorinated ethylene propylene (FEP) sold by DuPont, TFE/P rubber (Aflas™ by DuPont), perflouro elastomer (Kalrez™ by DuPont USA) and combinations thereof;
the crankshaft (axle) may be made of steel, stainless Steel, 4140 alloy steel and combinations thereof;
the upper and lower bearings may be made of steel or stainless steel and combinations thereof;
the upper and lower bushings may be made of steel, stainless steel, Phenolic resin laminate, glass filled nylon and combinations thereof;
the middle bushing may be made of Torlon™ by Solvay Specialty Polymers, poly-vinylidene fluoride, glass filled Teflon™, Teflon™, low density polyethylene (LDPE), high density polyethylene (HDPE), ultra high molecular weight (UHMW) Polyethylene, polypropylene, CE grade phenolic laminates, LE grade phenolic laminates, nylon and combinations thereof;
As many changes can be made to the disclosure herein without departing from the scope thereof; it is intended that all matter contained herein be considered illustrative and not in a limiting sense.
Filing Document | Filing Date | Country | Kind |
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PCT/CA2020/050412 | 3/30/2020 | WO | 00 |
Number | Date | Country | |
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62835056 | Apr 2019 | US |