Rotary piston internal combustion engine

Abstract

A rotary piston internal combustion engine includes an engine housing, an output shaft configured to rotate about an axis relative to the engine housing for transmitting power to an actuated component, a rotary piston eccentrically attached to the output shaft, a first bearing configured to support and facilitate rotation of the output shaft, the first bearing being sandwiched between a first pair of seals, and a second bearing configured to support and facilitate rotation of the rotary piston, the second bearing being sandwiched between a second pair of seals. The output shaft defines an internal passage having a first section for enabling a lubricating substance to flow between the first bearing and the second bearing during use.

Description

Technical Field

[0001] The present invention relates to a rotary piston internal combustion engine. More specifically, the present invention relates to a rotary piston internal combustion engine having a configuration that provides improved lubrication efficiency for internal bearings and sliding surfaces.

Background Art

[0002] Rotary piston internal combustion engines, such as Wankel engines, are known to include an elliptical epitrochoid-shaped cavity formed within an engine housing, a rotary piston, and an output shaft. The rotary piston has a generally triangular shape with convex arcuate sides. Apex seals are disposed at the three vertices of the rotary piston. During operation, the apex seals maintain physical contact with the inner peripheral surface of the cavity, thereby forming three combustion chambers. The cavity is provided with an inlet port and an exhaust port. The inlet port supplies fuel and / or an air charge to the cavity, and the exhaust port discharges exhaust gas to the atmosphere after combustion has occurred within the combustion chamber. Combustion of the fuel causes expansion of the combustion gases, resulting in an increase in pressure within the combustion chamber, thereby causing rotation of the rotary piston relative to the engine housing. For each rotation of the rotary piston, the output shaft rotates three times. Lubricating substances, such as oil, are introduced into the engine to lubricate moving parts (e.g., bearings and seals) to prevent overheating and seizure, thereby extending the life of the engine.

[0003] One known method of lubricating the moving parts of a rotary engine can be found in European Patent No. 2240671, which discloses a metering pump for supplying oil to a cooling circuit. The oil is carried by the circulating cooling or combustion gas to lubricate various components such as bearings, gears, and the internal sliding surfaces of the rotary pistons. Next, a portion of the oil exits the rotary piston, passes through an external duct, through a cooling heat exchanger and a pump, and is returned to the rotary piston. The circulating oil can also enter the engine's combustion chamber as part of the air induction charge. As a result, all the oil pumped into this type of engine is ultimately burned and discharged into the atmosphere.

[0004] The drawback of the lubrication system described in European Patent No. 2240671 is that a large amount of oil introduced into the engine is consumed. For example, the 225CS (trademark), a 40BHP rotary engine manufactured by Advanced Innovative Engineering of Lichfield, UK, which has the lubrication system taught by European Patent No. 2240671, consumes oil at a rate of approximately 150 cc / hour. In this engine, oil distribution is indiscriminate and depends on engine dynamics and system pressure. As a result, oil reaches components that do not require lubrication. Therefore, a large amount of lubricant is required to ensure that all the moving components of the engine are adequately lubricated. Furthermore, the oil can carry impurities, such as carbon accumulated from the sliding surfaces of the rotary pistons, which means that impure oil can move to other components such as bearings due to the fact that a portion of the oil can be recirculated.

[0005] Vehicles or devices containing such engines may have high hydrocarbon emissions depending on the amount of oil burned. This means that owners of such vehicles can be subject to fees, such as clean air fees, in countries with strict policies regarding vehicle emissions. Due to global warming, more stringent regulations may be adopted in many countries, which could lead to the banning of vehicles with high carbon emissions in some countries. Furthermore, since a large amount of oil is required to keep these engines in good condition, the maintenance costs are not low. Additionally, a large-capacity oil reservoir may be required to store the necessary oil, which is not ideal.

[0006] A non-exclusive object of the present invention is to overcome or at least substantially mitigate one or more of the problems associated with the prior art and / or the problems described above.

[0007] One object is to maintain lubrication performance while reducing oil consumption.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Means for Solving the Problems

[0009] According to a first aspect of the present invention, an engine housing, an output shaft configured to rotate about an axis relative to the engine housing for transmitting power to the actuated components, a rotary piston attached eccentrically to the output shaft, a first bearing configured to support and facilitate the rotation of the output shaft, the first bearing being sandwiched between a first pair of seals, A second bearing configured to support and facilitate rotation of the rotary piston, the second bearing being sandwiched between a second pair of seals and including An output shaft defines an internal passage including a first section to allow a lubricant (e.g., oil) to flow between the first bearing and the second bearing during use, and a rotary piston internal combustion engine is provided

[0010] The rotary piston internal combustion engine may be configured such that the lubricant flows from the first bearing to the second bearing

[0011] Optionally, the internal passage includes a second section to allow the lubricant to flow between the second bearing and a third bearing during use

[0012] The rotary piston internal combustion engine may be configured such that the lubricant flows from the second bearing to the third bearing

[0013] Optionally, the output shaft defines a bore that at least partially extends along an axis. The rotary piston internal combustion engine can further include a first barrier member. The first barrier member may be disposed within the bore between the first section and the second section. The first barrier member may be configured to direct the flow of the lubricant from the first section to the second bearing

[0014] Optionally, the first barrier member is configured to prevent the flow of the lubricant passing through the first barrier member along the bore

[0015] Optionally, the rotary piston internal combustion engine further includes a second barrier member. The second barrier member is disposed within the bore and may be configured to direct the flow of the lubricant from the second section to the third bearing

[0016] Optionally, the second barrier member is configured to prevent the flow of the lubricant passing through the second barrier member along the bore

[0017] Optionally, the rotary piston internal combustion engine further includes a rod disposed within the bore.

[0018] Optionally, the rod includes one or both of a first barrier member and a second barrier member.

[0019] Optionally, the rod is biased toward the first bearing. The rod may be biased by an elastic member such as a spring, for example a coil spring. The elastic member may be disposed within the bore.

[0020] Optionally, the third bearing is configured to support and facilitate rotation of the output shaft.

[0021] Optionally, the third bearing is in fluid communication with a thrust bearing.

[0022] Optionally, the third bearing and the thrust bearing are configured such that during use, a lubricating substance is received by the thrust bearing from the third bearing along a direction parallel to the axis.

[0023] Optionally, the thrust bearing includes a first side surface and a second side surface, the second side surface being spaced from the first side surface along the axis, the first side surface including an inlet for receiving a lubricating substance from the third bearing, and the second side surface including an outlet for the lubricating substance to exit the thrust bearing.

[0024] Optionally, the third bearing is sandwiched between the thrust bearing and a third seal.

[0025] Optionally, the first bearing and / or the third bearing include a ring, a retainer disposed within the ring and coaxially attached to the ring, rolling elements, and wherein the rolling elements are retained relative to the ring by the retainer.

[0026] Optionally, the retainer defines an opening extending from its outer surface to its inner surface, the opening receiving at least a portion of the rolling elements.

[0027] Optionally, the ring includes an inlet for receiving a lubricant.

[0028] Optionally, the ring includes a channel extending around its outer surface, the channel being in fluid communication with the inlet.

[0029] Optionally, the inlet is formed within the channel.

[0030] Optionally, the first pair of seals and / or the second pair of seals includes one or more seals configured to withstand a fluid pressure of 300 kPa or more. For example, the seals are configured to withstand a fluid pressure of 300 kPa to 10,000 kPa, such as 300 kPa to 1,000 kPa, for example 300 kPa to 500 kPa.

[0031] In one embodiment, the first pair of seals includes a first seal configured to withstand a fluid pressure of 300 kPa or more (such as 300 kPa to 1,000 kPa, for example 300 kPa to 500 kPa, etc., up to 300 kPa to 10,000 kPa) and a second seal configured to withstand a fluid pressure of up to 299 kPa (such as 50 kPa to 299 kPa).

[0032] In one embodiment, the second pair of seals includes first and second seals configured to withstand a fluid pressure of up to 299 kPa (such as 50 kPa to 299 kPa).

[0033] Optionally, the second bearing includes or consists of a ring fixed to the inner circumference of the rotary piston.

[0034] Optionally, the rotary piston internal combustion engine further includes a lubricant reservoir and a pump. The pump may be configured to pump lubricant from the lubricant reservoir to the first bearing.

[0035] Optionally, the rotary piston internal combustion engine further includes a rotor cooling system cavity and a lubricant reservoir, and during use, the lubricant reservoir is pressurized by the blow-by gas in the rotor cooling system cavity such that the lubricant flows from the lubricant reservoir to the first bearing.

[0036] Optionally, the lubricant reservoir is disposed inside or outside the engine housing.

[0037] Optionally, the rotary piston has a generally triangular shape with three apex seals. The inner circumferential surface of the engine housing can have a two-lobe epitrochoid shape. During use, the apex seals can maintain physical contact with the inner circumferential surface.

[0038] According to a second aspect of the present invention, a vehicle or device including a rotary piston internal combustion engine according to the first aspect of the present invention is provided.

[0039] The vehicle may be an automobile, a motorcycle, an aircraft (such as a drone), a jet ski, or a snowmobile.

[0040] The device may be a power tool such as a chainsaw.

[0041] Here, the present disclosure is described by way of example only with reference to the accompanying drawings.

Brief Description of the Drawings

[0042]

Figure 1a

Figure 1b

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10a

Figure 10b

Figure 11

Figure 12

Figure 13

Mode for Carrying Out the Invention

[0043] Referring to FIGS. 1a and 1b, an engine 1 is shown including an engine housing 10 configured to accommodate at least an output shaft 12 and a rotary piston 16. The engine housing 10 defines a cavity having an inner peripheral surface 104. The engine housing 10 can have an inlet port 100 and an exhaust port 102. The inlet port 100 may be configured to supply air and / or a fuel charge to the cavity. The exhaust port 102 may be configured to discharge exhaust gas, for example, to the atmosphere. The inner peripheral surface 104 can have a two-lobe epitrochoid shape. The rotary piston 16 can have a generally triangular shape. However, those skilled in the art will understand that alternative shapes of the inner peripheral surface 104 (e.g., an epitrochoid shape having three or more lobes) and the rotary piston 16 can be used without departing from the scope of the present disclosure. The rotary piston 16 can have an apex seal 160 at its apex. There may be one or more apex seals 160 disposed at each apex of the rotary piston 16. In use, the apex seal 160 may be configured to maintain physical contact with a lubricant substance on the inner peripheral surface 104. In some versions, the apex seal 160 may be configured to maintain physical contact with the inner peripheral surface 104. A combustion chamber 106 may be formed between the apex seal 160 and the inner peripheral surface 104. During combustion, the gas expands and increases the pressure within the combustion chamber 106. The high-pressure gas moves towards a higher volume region and drives the rotary piston 16 relative to the engine housing 10.

[0044] Referring to FIGS. 3-5, the rotary piston 16 is eccentrically attached to the output shaft 12. When the rotary piston 16 is driven, the output shaft 12 also rotates relative to the engine housing 10 about an axis 14. For each rotation of the rotary piston 16, the output shaft 12 rotates three times. Thus, power can be transmitted to an actuated component, such as an axle or a rotor blade.

[0045] The first bearing 18 is configured to support and facilitate the rotation of the output shaft 12. In use, the first bearing 18 may be arranged towards the first end 12a of the output shaft 12.

[0046] The second bearing 11 is configured to support and facilitate the rotation of the rotary piston 16. In some embodiments, the second bearing 11 may consist of only a ring fixed to the inner circumference 162 of the rotary piston 16.

[0047] The engine 1 can include a third bearing 15 that can be configured to support and facilitate the rotation of the output shaft 12. In use, the third bearing 15 can be arranged towards the second end 12b of the output shaft 12, which is opposite the first end 12a. The rotary piston 16 may be positioned between the first bearing 18 and the third bearing 15 along the axis 14.

[0048] Referring to FIG. 6, the first bearing 18 can include a ring 182 and a retainer 184. The retainer 184 can be disposed within the ring 182 and coaxially attached thereto. The rolling elements 186 can be held by the retainer 184 against the ring 182. The retainer 184 can define an opening 1840. The opening 1840 can extend from the outer surface of the retainer 184 to the inner surface thereof. The opening 1840 may be configured to receive at least a portion of the rolling elements 186. In some embodiments, there may be a plurality of rolling elements 186 and respective openings 1840. During use, the rolling elements 186 may be in physical contact with the output shaft 12. The ring 182 can include an inlet 1820 configured to receive a lubricating substance. The ring 182 can include a channel 1822 extending around its outer surface. The channel 1822 may be in fluid communication with the inlet 1820. For example, the inlet 1820 may be formed within the channel 1822.

[0049] In embodiments including the third bearing 15, the third bearing 15 can have the same or a similar configuration as the first bearing 18.

[0050] Referring again to FIG. 3, the first bearing 18 may be sandwiched between the first pair of seals 180. The first pair of seals 180 can include one or more high-pressure seals configured to withstand a fluid pressure of 300 kPa or more. The one or more high-pressure seals may be configured to withstand a fluid pressure of 300 kPa to 10,000 kPa, such as 300 kPa to 1,000 kPa, for example 300 kPa to 500 kPa. For example, the one or more high-pressure seals may be multiple (e.g., double) lip high-fluid pressure seals. The first pair of seals can include one or more low-pressure seals configured to withstand a fluid pressure of up to 299 kPa. The one or more low-pressure seals may be configured to withstand a fluid pressure of 50 kPa to 299 kPa. For example, the one or more low-pressure seals may be configured to withstand a fluid pressure of 100 kPa to 299 kPa. In some embodiments of the present disclosure, the first pair of seals 180 can include a high-pressure seal 1800 configured to withstand a fluid pressure of 300 kPa or more and a low-pressure seal 1802 configured to withstand a fluid pressure of up to 299 kPa (FIG. 7).

[0051] The second bearing 11 may be sandwiched between the second pair of seals 110. The second pair of seals 110 may be low-pressure seals configured to withstand a fluid pressure of up to 299 kPa.

[0052] The third bearing 15 may be sandwiched between a pair of seals. The third bearing 15 may be sandwiched between the third seal 150 and the thrust bearing 17. The third bearing 15 may be in fluid communication with the thrust bearing 17. The third seal 150 may be a low-pressure seal configured to withstand a fluid pressure of up to 299 kPa.

[0053] The thrust bearing 17 may be a conventional rotary bearing such as a ball bearing. The thrust bearing 17 may include a first side surface 170 and a second side surface 172 spaced apart from the first side surface 170. The thrust bearing 17 may include an inlet 1700 and an outlet 1720 (FIG. 7).

[0054] Referring to FIG. 3, the output shaft 12 defines an internal passage 13. In use, the lubricant can flow from the first bearing 18 to the second bearing 11 along a first section 130 of the internal passage 13. The lubricant can flow from the second bearing 11 to the third bearing 15 along a second section 132 of the internal passage 13.

[0055] The output shaft 12 can define a bore 120 that at least partially extends between a first end 12a and a second end 12b along an axis 14.

[0056] In some embodiments, the rod 19 may be disposed within the bore 120. The rod 19 may be hollow. The rod 19 may be made of aluminum. The rod 19 can have a first end 190 and a second end 192.

[0057] The rod 19 can include a first barrier member 1200. In use, the first barrier member 1200 may be disposed between the first section 130 and the second section 132. The first barrier member 1200 prevents a continuous flow of lubricant along the bore 120 by redirecting the flow from the first section 130 to the second bearing 11 again. As shown, the first barrier member 1200 can include a thickened portion of the rod 19. The first barrier member 1200 can have a conical shape. However, in some embodiments, the first barrier member 1200 can take another form such as a deflector portion extending from the rod 19. In some embodiments, the first barrier member 1200 may not form part of the rod 19. For example, the first barrier member 1200 may form another component of the engine 1 such as the inner wall or a part of the output shaft 12.

[0058] The rod 19 can include a second barrier member 1202. In use, the second barrier member 1202 may be disposed between the second section 132 and the second end 12b of the output shaft 12. The second barrier member 1202 prevents a continuous flow of lubricant along the bore 120 by redirecting the flow from the second section 132 back to the third bearing 15. As shown, the second barrier member 1202 can include a thickened portion of the rod 19. However, in some embodiments, the second barrier member 1202 can take another form, such as a deflector portion extending from the rod 19. In some embodiments, the second barrier member 1202 may not form part of the rod 19. For example, the second barrier member 1202 may form part of another component of the engine 1, such as the inner wall or a portion of the output shaft 12.

[0059] The rod 19 serves two important purposes. First, the rod 19 includes a first barrier member 1200 and a second barrier member 1202, which function as diverters to ensure that oil is reliably redirected from the bore 120 to the respective second bearing 11 and third bearing 15. Second, the presence of the rod 19 minimizes the amount of oil required to prime the engine. This is because the rod 19 occupies volume within the bore 120. In versions where the rod 19 is hollow, this can help improve the overall weight gain, which can be particularly advantageous, for example, in aerospace applications.

[0060] The rod 19 may be biased towards the first end 12a of the output shaft 12. The rod 19 may be elastically biased by a spring 1206 acting on the second end 192 of the rod 19 (Figure 7). The spring 1206 can ensure that the rod 19 remains accurately seated during use. For example, the spring 1206 can account for different thermal expansions of the output shaft 12 and the rod 19.

[0061] Next, the first section 130 and the second section 132 of the internal path 13 will be further described with reference to FIG. 9. The first section 130 can include a first portion 1300, a second portion 1302, and a third portion 1304. The second section 132 can include a first portion 1320, a second portion 1322, and a third portion 1324.

[0062] The first portions 1300 and 1302 of the first section 130 and the second section 132, and the first portions 1320 and 1322 of the first section 130 and the second section 132 may be substantially perpendicular to the axis 14. The third portions 1304 and 1324 of the first section 130 and the second section 132 may be substantially parallel to the axis 14.

[0063] When a lubricant is delivered to the first bearing 18 (described in more detail below), the lubricant can enter the first section 13 through the first portion 1300 and flow along the third portion 1304 until it is redirected into the second portion 1302 by the first barrier member 1200. Next, the lubricant flows into the second bearing 11 before being sequentially delivered to the first portion 1320 and the third portion 1324 of the second section 132 until it is redirected into the second portion 1322 by the second barrier member 1202. Next, the lubricant flows into the third bearing 15 and out through the thrust bearing 17.

[0064] In a version that does not include the rod 19, the output shaft 12 can include two bores (not shown). The first bore may be drilled into the output shaft 12 from the first end 12a, and the second bore may be drilled into the output shaft 12 from the second end 12b. In such a version, the first portion 1300 and the second portion 1302 of the first section 130 may be in fluid communication with the first bore. The first portion 1320 and the second portion 1322 of the second section 132 may also be in fluid communication with the second bore. The first barrier member 1200 may be defined by a section of the output shaft 12 that separates the first bore from the second bore.

[0065] Referring to FIGS. 10a and 10b, the engine 1 can further include a lubricant reservoir 2 and a pump 4. The lubricant reservoir 2 may be disposed inside (FIG. 10a) or outside (FIG. 10b) of the engine housing 10. Referring to FIG. 10b, the lubricant reservoir 2 can have a calibrated sight glass 20 configured to enable a user to determine the lubricant level. The pump 4 may be configured to pump lubricant from the lubricant reservoir 2 to the first bearing 18. In some embodiments of the present disclosure, the pump 4 may be controlled by an engine control unit (ECU). The ECU may be configured to receive relevant information from sensors disposed on the engine 1. The sensors can include temperature, pressure, level, and / or flow rate sensors. Alternatively, the pump 4 may be manually controlled.

[0066] Referring to FIG. 11, lubricant can be supplied to the first bearing 18 via an inlet 108 and a supply channel 1080. The supply channel 1080 can supply lubricant to a channel 1822 of the first bearing 18.

[0067] Referring to FIG. 12, the engine 1 can further include a metering valve 6. The metering valve 6 may be configured to control the amount of lubricant delivered to the inner circumferential surface 104 of the engine housing 10 to provide lubrication to the contact surface of the rotary piston 16 itself.

[0068] Referring to FIG. 13, the engine 1 can further include a self - pressurized air rotor cooling system (SPARCS). The SPARC can include a rotor cooling system cavity 81.

[0069] Referring to FIG. 2, the rotary piston 16 can have a first face 168 and a second face 169. The first face 168 and the second face 169 may be on opposite sides of the rotary piston 16. One or more side seals 166 may be positioned on the first face 168 and / or the second face 169. The side seal 166 may be disposed between the apex seals 160.

[0070] Referring to FIGS. 1a and 1b, the combustion gas in the working chamber 106 may leak through the side seal 166 into the passage located within the rotary piston 16. These leaked combustion gases are called blow-by gases. The blow-by gases can enter the rotor cooling system cavity 81 (FIG. 13) through the passage. Thus, the rotor cooling system cavity 81 can be pressurized. In such a version, the lubricant reservoir 2 may be pressurized by the blow-by gases within the rotor cooling system cavity 81 (indicated by the double arrows shown at A in FIG. 13). Thus, the pure oil from the lubricant reservoir 2 can be pushed onto the first bearing 18 by the pressure acting on the lubricant reservoir 2 (indicated by the arrow shown at B in FIG. 13). Thereby, the pump 4 (shown in FIG. 12) may not be required.

[0071] A separate direct supply from the lubricant reservoir 2 to the inner peripheral surface 104 of the engine may be provided, but this is likely not necessary as initial tests have shown that sufficient lubricant can reach all of the essential components of the engine via the internal passage of the output shaft 12.

[0072] Referring to FIGS. 10a and 10b, pump 4 pumps lubricant from lubricant reservoir 2 through first bearing 18 into the internal passage 13 of engine housing 10. In one embodiment of the present invention, pump 4 is controlled by an engine control unit (ECU). Sensors disposed on engine 1 transmit relevant information regarding the physical state of engine 1 (e.g., oil level, pressure, temperature, and flow rate) to the ECU. The relevant information may be transmitted at predetermined intervals. Next, the flow rate of the lubricant supplied to first bearing 18 is adjusted by the ECU based on the relevant information to compensate for any variations in the physical properties of the lubricant, such as viscosity. For example, at higher temperatures, the viscosity of the lubricant within engine 1 may decrease, and thus a lower flow rate is required to achieve sufficient lubrication. The ECU ensures that an optimal amount of lubricant is reliably supplied to the engine, thereby limiting waste of the lubricant. In another embodiment of the present disclosure, pump 4 is manually controlled. The user can determine the amount of lubricant consumed over a period of time by observing changes in the lubricant level from calibrated sight glass 20 on lubricant reservoir 2. Alternatively, sensors installed on engine 1 provide relevant information (e.g., remaining amount of lubricant, pressure, temperature, and flow rate) to the user via a user interface. The user can then appropriately change the flow rate of the lubricant by adjusting the power of pump 4.

[0073] In some embodiments, particularly referring to FIGS. 6 and 11, the lubricant is pumped to inlet 108 of engine housing 10. The lubricant then flows along supply channel 1080 until it reaches channel 1822 of first bearing 18. The lubricant flows along channel 1822 until it enters inlet 1820. The lubricant then lubricates the contact surface between rolling element 186 and output shaft 12. As output shaft 12 rotates, rolling element 186 also rotates in the same direction. The lubricant is further distributed between the contact surfaces. This reduces the axial vibration of output shaft 12 by first bearing 18, ensuring smooth rotation along axis 14.

[0074] The first pair of seals 180 is provided to direct the flow of lubricant from the first bearing 18 through the first portion 1300 to the first section 130 of the internal passage 13. Similarly, the second pair of seals 110 is provided to direct the flow of lubricant from the second bearing 11 through the first portion 1320 to the second section 132 of the internal passage 13. The third seal 150 is also provided to direct the flow of lubricant within the third bearing 15 to the inlet of the first side 1700 of the thrust bearing 17. In some embodiments, the third bearing 15 and the thrust bearing 17 are configured such that the lubricant is received by the thrust bearing 17 along a direction parallel to the axis 14. Next, the lubricant lubricates the thrust bearing 17 and exits from the outlet of the second side 1720 of the thrust bearing 17.

[0075] The engine 1 has the following advantages.

[0076] First, the consumption of lubricant by the engine 1 is significantly reduced compared to the prior art. This is because the lubricant is specifically directed to the locations that require lubrication, namely the first bearing 18, the second bearing 11, and the third bearing 15, and is not directed to components that require little or no lubrication. This controlled supply of lubricant to the engine 1 ensures that waste is minimized. The engine according to the present invention has been shown to consume oil at a rate of approximately 10 cc / hour compared to approximately 150 cc / hour in the prior art. Therefore, the engine of the present disclosure has lower hydrocarbon emissions compared to the prior art and is thus more environmentally friendly than prior art engines.

[0077] Second, the bearings receive pure oil or substantially pure oil by virtue of the lubricant being delivered specifically to these locations first. The lubricant does not mix with impurities inside the engine 1, such as impurities from the sliding surfaces of the rotary pistons, before contacting the bearings. This can lead to an extension of the lifespan of these moving components.

[0078] Thirdly, since a lubricating substance of a considerably small volume is required, for example, by reducing the volume of the lubricating substance reservoir, the overall size and / or weight of the vehicle or device can be reduced. This advantage is particularly beneficial when the engine is used in an aircraft such as an unmanned aerial vehicle.

[0079] Fourthly, by having a controlled flow path for the lubricating substance, the required control means are simplified and there is only one inlet and one outlet for the lubricating substance. These simplified control means can provide more accurate control used by the ECU and further enhance the reliability of the engine 1.

[0080] Those skilled in the art will readily understand that additional bearings configured to support and facilitate the rotation of the output shaft 12 can be provided. Further, the engine 1 can include one or more additional rotary pistons 16. Such rotary pistons can include their respective associated bearings, as will be understood by those skilled in the art.

[0081] Furthermore, although the embodiment shown in the figures shows the lubricating substance being delivered from the lubricating substance reservoir 2 to the first bearing 18, those skilled in the art will understand that, without departing from the scope of the present invention, the lubricating substance can alternatively be delivered to any one of the other bearings, for example the second bearing 11 or the third bearing 15.

[0082] As used in this specification and the claims, the terms "comprises" and "comprising" and their variants mean that the specified features, steps or integers are included. These terms should not be construed as excluding the presence of other features, steps or components.

[0083] The present invention may also be broadly applicable to the parts, elements, steps, examples, and / or features mentioned or shown herein, individually or collectively in any and all combinations of two or more of the foregoing parts, elements, steps, examples, and / or features. In particular, one or more features in any of the embodiments described herein may be combined with one or more features from any other embodiment described herein.

[0084] Protection may be sought for any feature disclosed in any one or more of the published documents referenced herein in combination with the present disclosure.

[0085] Although certain exemplary embodiments of the present invention are described, the appended claims are not intended to be limited to only these embodiments. The claims should be construed literally to cover the objects as appropriate and / or to include equivalents.

Claims

1. A rotary piston internal combustion engine, Engine housing and An output shaft configured to rotate about an axis relative to the engine housing for transmitting power to the operating parts, A rotary piston is mounted eccentrically on the output shaft, A first bearing configured to support and facilitate the rotation of the output shaft, comprising a first bearing sandwiched between a first pair of seals, A second bearing configured to support and facilitate the rotation of the rotary piston, the second bearing sandwiched between a second pair of seals Includes, The rotary piston internal combustion engine further comprises a first barrier member, the first barrier member being located within the bore between the first and second sections, and the first barrier member being configured to direct the flow of the lubricant from the first section to the second section.

2. The rotary piston internal combustion engine according to claim 1, wherein the first barrier member is configured to prevent the flow of the lubricating substance through the first barrier member along the bore.

3. The rotary piston internal combustion engine according to claim 1, further comprising a second barrier member, the second barrier member being disposed within the bore and configured to direct the flow of the lubricating substance from the second section to the third bearing.

4. The rotary piston internal combustion engine according to claim 3, wherein the second barrier member is configured to prevent the flow of the lubricating substance through the second barrier member along the bore.

5. The rotary piston internal combustion engine according to claim 1, further comprising a rod disposed within the bore.

6. The rotary piston internal combustion engine according to claim 5, wherein the rod includes one or both of the first barrier member and the second barrier member.

7. The rotary piston internal combustion engine according to claim 5, wherein the rod is biased toward the first bearing.

8. The rotary piston internal combustion engine according to claim 1, wherein the third bearing is configured to support and facilitate the rotation of the output shaft.

9. The rotary piston internal combustion engine according to claim 1, wherein the third bearing is in fluid communication with the thrust bearing.

10. The rotary piston internal combustion engine according to claim 9, wherein the second bearing and the thrust bearing are configured such that, during use, the lubricating substance is received by the thrust bearing from the second bearing in a direction parallel to the axis.

11. The rotary piston internal combustion engine according to claim 9, wherein the thrust bearing includes a first side surface and a second side surface, the second side surface being spaced apart from the first side surface along the axis, the first side surface including an inlet for receiving the lubricant from the third bearing, and the second side surface including an outlet for the lubricant to exit the thrust bearing.

12. The rotary piston internal combustion engine according to claim 9, wherein the third bearing is sandwiched between the thrust bearing and the third seal.

13. The first bearing and / or the third bearing are A ring, A retainer is disposed within the ring and mounted coaxially with respect to the ring, Rolling elements and Includes, The rotary piston internal combustion engine according to claim 1, wherein the rolling element is held in place of the ring by the retainer.

14. The rotary piston internal combustion engine according to claim 13, wherein the retainer defines an opening extending from its outer surface to its inner surface, and the opening receives at least a portion of the rolling element.

15. The rotary piston internal combustion engine according to claim 13, wherein the ring includes an inlet configured to receive the lubricating substance.

16. The rotary piston internal combustion engine according to claim 15, wherein the ring includes a channel extending around its outer surface, the channel being in fluid communication with the inlet.

17. The rotary piston internal combustion engine according to claim 16, wherein the inlet is formed within the channel.

18. The rotary piston internal combustion engine according to claim 1, wherein the first pair of seals and / or the second pair of seals include one or more seals configured to withstand a fluid pressure of 300 kPa or more.

19. The rotary piston internal combustion engine according to claim 18, wherein the first pair of seals includes a first seal configured to withstand a fluid pressure of 300 kPa or more, and a second seal configured to withstand a fluid pressure of up to 299 kPa.

20. The rotary piston internal combustion engine according to claim 1, wherein the second bearing comprises a ring fixed to the inner circumference of the rotary piston.

21. The rotary piston internal combustion engine according to claim 1, further comprising a lubricant reservoir and a pump, wherein the pump is configured to pump the lubricant from the lubricant reservoir to the first bearing.

22. The rotary piston internal combustion engine according to claim 1, further comprising a rotor cooling system cavity and a lubricant reservoir, wherein, during use, the lubricant reservoir is pressurized by blow-by gas in the rotor cooling system cavity so that the lubricant flows from the lubricant reservoir to the first bearing.

23. A vehicle or apparatus comprising a rotary piston internal combustion engine according to any one of claims 1 to 22.

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