Drive motor with tangential force transmission

Description

[0001] The present invention relates to a novel drive motor with tangential power transmission, a method for operating the drive motor, a use of the drive motor in a machine or for driving a motor vehicle, aircraft or ship and a machine, motor vehicle, aircraft or ship containing the drive motor. Background of the invention

[0002] CH 189 224 A discloses a free-piston engine with a compressor and at least two internal combustion free-piston engines which move in such a way that the compression stroke of one coincides with the expansion stroke of the other, characterized in that the drive of the compressor is derived from a column of liquid connected between the internal combustion free-piston engines and moving with them, without the use of a crank mechanism.

[0003] Pneumatic motors / compressed air motors can be used in industrial applications, such as in medical technology, foundries, shipbuilding, and the chemical industry, because they offer high power density, deliver high torque even at low speeds, and can be safely used in potentially explosive atmospheres. These properties can also be advantageous in mobile applications such as motor vehicles, aircraft, or ships.

[0004] Given the high energy consumption involved in supplying compressed air to power the motors, increasing efficiency plays a central role in their development. Furthermore, the applications mentioned above require high torque output across the entire speed range of the motor.

[0005] The present invention aims to further improve the efficiency and operating behavior of a pneumatic motor. Disclosure of the invention

[0006] The present invention therefore provides a drive motor that combines a pneumatic drive with a hydraulic transmission. The drive elements of the motor can be designed / scaled to cover different power classes. The hydraulic transmission enables high torque across the entire speed range of the motor.

[0007] The drive motor according to the invention can be of any size, from relatively small versions, such as a motor for a motorcycle or an industrial application in the medical field, to car, boat and aircraft engines, up to very large versions such as ship engines or an industrial application in a foundry or shipbuilding. Its compact form allows for space-saving installation.

[0008] The drive motor comprises a shaft on which a drive element is arranged, a first cylinder with a first driving piston movably arranged therein, and a second cylinder with a second driving piston movably arranged therein. The first and second cylinders, as well as the first and second driving pistons, can be of identical construction, in particular having the same diameter and the same length or stroke.

[0009] According to one embodiment, the first drive piston can be mechanically connected to the second drive piston, and the drive pistons can move back and forth in opposite directions within the two cylinders. The mechanical connection between the two drive pistons can, in particular, be a push rod. Specifically, the push rod can be arranged in the first and second cylinders in such a way that it can move freely.

[0010] It can also be provided, in particular, that the first and second drive pistons are designed as a single-piece or one-piece drive piston unit via the push rod. Alternatively, this drive piston unit can also be designed in multiple parts.

[0011] The first and second cylinders each have a first chamber and a second chamber, wherein the first chamber is arranged on one side of the first or second driving piston and can be pressurized with a first fluid, and the second chamber is arranged on the opposite side of the first or second driving piston and contains a second fluid. In particular, the first chamber can adjoin a top surface of the first or second driving piston, and the second chamber can adjoin a bottom surface of the first or second driving piston.

[0012] The passage of the push rod from the first to the second cylinder can be fluid-tight with respect to the second fluid.

[0013] The first and second cylinders can be designed as separate units, for example as tubes bolted together. It is also possible for the two cylinders to be designed as bores within a single cylinder block.

[0014] In particular, the first fluid can be a gas and the second fluid a liquid.

[0015] The first fluid can be a pressurized gas, such as compressed air. The second fluid can be, for example, a hydraulic fluid, such as a mineral oil-based or water-based fluid.

[0016] The pressurized gas can be supplied to the first chamber of the first or second cylinder via at least one fluid inlet and discharged again via at least one fluid outlet. These fluid inlets and outlets can be, for example, inlet and outlet valves, which may be designed as poppet and / or slide valves. It is also possible that the fluid inlets and outlets are formed simply by, for example, connection fittings, and that the gas supply and discharge are controlled externally.

[0017] The first drive piston is fluidically coupled to a first working piston in a first working cylinder via the second fluid, and the second drive piston is fluidically coupled to a second working piston in a second working cylinder via the second fluid. The first and second working cylinders, as well as the first and second working pistons, can be identical in design, in particular having the same diameter and length or stroke. As a rule, the cylinders / working cylinders, and consequently also the drive / working pistons, have a circular cross-section.

[0018] The first and second working pistons move back and forth in opposite directions within the first and second working cylinders and are operatively connected to the drive element. The two working cylinders can be designed, particularly in the stroke area of ​​the working pistons, such that the working pistons seal against the inner walls of the working cylinders.

[0019] The term "opposing movement" of the drive pistons and / or working pistons refers to the fact that when the first drive / working piston performs a forward stroke, the second drive / working piston performs a return stroke. The terms "forward stroke" and "return stroke" refer to the movement of a piston (drive piston or working piston) within its respective cylinder. "Forward stroke" describes a movement of the piston that results in an increase in the volume of the cylinder above the piston, and "return stroke" describes a movement of the piston that results in a decrease in the volume of the cylinder above the piston.

[0020] According to one embodiment, the first working cylinder can be connected at its upper end to the second chamber of the first cylinder and closed at its lower end by the first working piston. Similarly, the second working cylinder can be connected at its upper end to the second chamber of the second cylinder and closed at its lower end by the second working piston.

[0021] Due to the fluidic connection between the first drive piston and the first working piston, a forward stroke movement of the first drive piston induces a forward stroke movement of the first working piston in the first working cylinder. Typically, the second fluid (e.g., hydraulic fluid) is conveyed / forced from the second chamber of the first drive cylinder into the first working cylinder. According to one embodiment, the opposing movement of the two drive pistons can additionally induce a return stroke movement of the second drive piston, thereby conveying / drawing hydraulic fluid from the second working cylinder into the second chamber of the second cylinder.

[0022] Similarly, the fluidic connection between the second drive piston and the second working cylinder induces a forward stroke movement of the second drive piston within the second working cylinder, during which hydraulic fluid is typically pumped / forced into the second working cylinder. Conversely, a return stroke movement of the first drive piston can also be induced, thereby pumping / drawing hydraulic fluid from the first working cylinder into the second chamber of the first cylinder.

[0023] In this way, during a working stroke (forward stroke movement) induced by the respective drive piston of one of the two working pistons, the working stroke of the other working piston is simultaneously prepared by pumping hydraulic fluid back into the corresponding cylinder for the subsequent working stroke through the return stroke movement of the other drive piston.

[0024] In the case of the return of hydraulic fluid from the working cylinder described above, the reduction in the cylinder space above the driving piston (first space) associated with the return stroke movement of the respective drive piston causes an increase in the cylinder space below it (second space), which causes the pressure in the second space to drop and hydraulic fluid to be drawn from the working cylinder into it.

[0025] The pre-stroke movement of the first / second drive piston is generated by applying the first fluid (e.g. compressed air) to the first chamber of the respective cylinder, thereby exerting a force on the upper surface of the corresponding drive piston adjacent to the first chamber.

[0026] For this purpose, the exhaust valve of the corresponding cylinder can be closed and its inlet valve opened to direct the compressed air into the cylinder. In particular, the exhaust valve of the other cylinder can be open during the subsequent forward stroke of the drive piston, so that the other drive piston can expel already expanded compressed air during the return stroke.

[0027] Compressed air can be supplied, for example, by a compressor, which can be driven by an electric motor. It is also possible for the compressor to be driven by an internal combustion engine or a turbine. The compressor could be, for example, a screw compressor, a scroll compressor, or a piston compressor.

[0028] According to one embodiment, if the first or second drive piston is located at a position with minimum or maximum distance to the upper end of the first or second cylinder, the first or second working piston can also be located at a position with minimum or maximum distance to the upper end of the first or second working cylinder.

[0029] In other words, the hydraulic fluid allows for the coupling / synchronization of the piston strokes between the drive piston and the working piston. Due to this hydraulic coupling to the opposing drive pistons, the working pistons also execute an opposing movement.

[0030] To achieve the fluidic connection, the second chamber of the first and second cylinders can each be connected to the first and second working cylinders, respectively, by means of a pipe. The two connecting pipes can be identical in design.

[0031] It is also possible that the first and second cylinders, as well as the two working cylinders, are integrated into a common cylinder block. In this case, the second chamber of the first or second cylinder can, for example, be connected to the first or second working cylinder via a bore in the cylinder block.

[0032] In particular, the second chamber of the first and second cylinders and the first and second working cylinders can have the same volume, allowing the first and second cylinders to have a longer piston stroke than the first and second working cylinders. Thus, the first and second cylinders are designed as so-called "long-stroke" cylinders, which are characterized by lower heat transfer losses.

[0033] Typically, the cylinders / working cylinders have at least one opening for filling and / or emptying the hydraulic fluid, which may be located, for example, in the connecting pipe / connecting bore between the first / second cylinder and the first / second working cylinder, preferably closable.

[0034] The operative connection between the working pistons and the drive element is arranged in such a way that a force generated by the back-and-forth movement of the working pistons is transmitted tangentially to the drive element and the drive element sets the shaft into a continuous rotational movement.

[0035] In other words, the force generated by the forward stroke of the respective drive and working pistons is transmitted to the respective freewheel in such a way that the force is always transmitted tangentially, i.e., at a sinusoidal angle of 90°. For this purpose, both the cylinders of the drive pistons and the working cylinders are designed in a circular arc shape. In particular, the longitudinal axes of the cylinders, along which the pistons move, can have a circular arc shape.

[0036] The drive motor according to the present invention can also be called a "tangential drive motor" or simply a "tangential motor" due to the special design and arrangement of the cylinders and the special transmission of the forces arising when the drive pistons are pressurized into a torque.

[0037] According to one embodiment, the ratio of the maximum possible circular arc movements of the push rod or the first and second rack, expressed in degrees, to the maximum circular arc movement of the freewheels transmitted to the outside, expressed in degrees, can be greater than 1, preferably greater than 1.1 and more preferably greater than 1.25.

[0038] The design of the tangential motor ensures that the tangential forces always act or are transmitted at the maximum possible sinusoidal angle of 90° throughout the entire working process. Furthermore, the tangential motor does not require a flywheel, and the stroke of the driving and working pistons is not limited by mechanical dead centers, allowing for a freewheel angle greater than 180° during each reciprocating movement of the working pistons. Thus, the motor according to the invention offers the advantages of achieving both the highest possible torque at low speeds and a virtually constant torque across different speeds. This results in greater efficiency compared to conventionally designed pneumatic motors, and consequently, a more environmentally friendly design.

[0039] According to one embodiment, the two working pistons can have a larger diameter than the two driving pistons, thereby creating a force multiplier. This can serve to increase the tangential force transmitted to the drive element by the working pistons compared to the force transmitted by the driving pistons. This allows the motor's torque to be increased further or a more uniform torque delivery to be achieved.

[0040] According to one embodiment, the drive element can comprise a first freewheel and a second freewheel, and the first working piston can be operatively connected to an outside of the first freewheel and the second working piston to an outside of the second freewheel.

[0041] The freewheels of the drive element can be identical in design.

[0042] Typically, freewheels each have an outer and an inner surface, which can be designed, for example, as an outer and inner ring that can lock against each other (drive-through mode) or run freely (freewheel mode).

[0043] In particular, the inner surfaces of the freewheels can each be connected to the shaft in such a way that they freewheel or lock in the same direction. This allows continuous rotation of the shaft in one direction.

[0044] The operative connections of the working pistons with the outer surface of the first and second freewheels can be designed such that a reciprocating movement of the first working piston causes a rotary reciprocating movement of the first freewheel, and a reciprocating movement of the second working piston causes an opposing rotary reciprocating movement of the second freewheel. In this way, for example, a forward stroke movement of the first and second working pistons, induced by a corresponding forward stroke movement of the associated drive piston, can cause a continuous rotational movement of the shaft.

[0045] According to one embodiment, the operative connection between the working pistons and the freewheels can be formed by means of a toothed connection. For example, both the working pistons and the freewheels can each have a toothed connection or toothed element.

[0046] In particular, the first working piston can be connected to a first rack and the second working piston to a second rack.

[0047] The racks are usually connected to the undersides of the working pistons, preferably rigidly connected.

[0048] The force is transmitted tangentially via the rack to the outer surface of the freewheel associated with the working cylinder, which in turn converts the force into a torque on its inner surface. This torque is then transmitted to the shaft via the inner surface of the locking freewheel, which is connected to the shaft.

[0049] Furthermore, the outer surface of the first freewheel can have a first toothing on its front face and the outer surface of the second freewheel can have a second toothing on its front face.

[0050] In this case, the operative connection of the first working piston to the first freewheel can be formed, for example, via a first gear, and the operative connection of the second working piston to the second freewheel can be formed, for example, via a second gear. The two gears can each be arranged between the corresponding rack and the teeth of the associated freewheel.

[0051] In particular, the first and second racks can be shaped like circular arcs to transmit the force provided by the working pistons tangentially to the freewheels via the first and second gears. For this purpose, the gears can, for example, engage both with teeth on the inside of the circular arc-shaped racks and with teeth on the face of the freewheels. In this way, the force can be transmitted to the shaft, for example, first via the inside of the first freewheel, and then, during the counter-rotation, via the inside of the second freewheel.

[0052] According to one embodiment, the first rack can additionally be connected to a first guide piston, which is movably arranged in a first guide cylinder and moves in the opposite direction to the first working piston. Similarly, the second rack can additionally be connected to a second guide piston, which is movably arranged in a second guide cylinder and moves in the opposite direction to the second working piston.

[0053] It can be provided, in particular, that the first working piston and the first guide piston form a one-piece or single-piece first working piston unit via the first rack. Similarly, it can be provided that the second working piston and the second guide piston form a one-piece or single-piece second working piston unit via the second rack. However, it is also possible for the first and / or second working piston unit to be multi-piece.

[0054] Gears and corresponding racks can be easily designed and offer high operational reliability as well as reliable power transmission.

[0055] Typically, gears, racks or pinions, pistons and any bearings of the drive motor according to the invention are supplied with lubricant in a conventional manner.

[0056] According to one embodiment, the first guide cylinder can be arranged opposite the first working cylinder in a cross-sectional view of the drive motor, and the second guide cylinder can be arranged opposite the second working cylinder in a cross-sectional view of the drive motor.

[0057] Advantageously, the two guide cylinders can be arranged relative to the working cylinders in such a way that a forward stroke movement of the working pistons in the working cylinders results in a return stroke movement of the guide pistons in the guide cylinders. For this purpose, the guide cylinders can also be designed in a circular arc shape.

[0058] According to one embodiment, the two working cylinders and the two guide cylinders can be arranged at the same radial distance from the shaft.

[0059] In particular, the first working cylinder and the first guide cylinder, together with the first working piston unit, can form a first working cylinder unit driven by the first driving piston. Similarly, the second working cylinder and the second guide cylinder, together with the second working piston unit, can form a second working cylinder unit driven by the second driving piston.

[0060] The individual cylinders can be designed as separate units, e.g., as tubes bolted together. However, it is also possible for the two working cylinder units to be arranged in a common cylinder block. This block can also include both cylinders with their driving pistons.

[0061] According to one embodiment, the first working cylinder can be arranged axially alongside / behind the second guide cylinder, and the second working cylinder can be arranged axially alongside / in front of the first guide cylinder. In other words, the first and second working cylinder units can be arranged one behind the other axially along the shaft.

[0062] According to one embodiment, the first cylinder with the first drive piston and the second cylinder with the second drive piston can be arranged opposite each other in a cross-sectional view of the drive motor and at the same radial distance from a central axis that runs parallel to the shaft. In other words, the first and second cylinders can be arranged below or, in particular, above the working cylinder units.

[0063] The present invention further relates to a method for operating a drive motor in one of the embodiments described herein.

[0064] The method according to the invention comprises the following steps: a) Pressurizing a first chamber on one side of a drive piston in a cylinder with a first fluid to generate a pre-stroke movement of the drive piston; b) Inducing a pre-stroke movement of a working piston in a working cylinder by means of a fluidic connection of the drive piston to the working piston via a second fluid; and c) Driving a shaft of the drive motor by means of a drive element that is mechanically connected to the working piston.

[0065] The invention also relates to a motor vehicle, aircraft or ship, comprising at least one drive motor according to the invention.

[0066] The drive motor according to the invention can comprise exactly two cylinder units, but also more than two cylinder units. A cylinder unit can comprise a cylinder with a drive piston, which is (fluidically) connected to a working cylinder unit. In particular, the drive motor according to the invention can contain multiples of two cylinder units, for example, 2, 4, 6 cylinder units, etc.

[0067] Unless explicitly stated otherwise, where applicable, all embodiments described as "customary," "ordinary," or "preferable" that relate to a cylinder and / or its associated or related components shall also be considered "customary," "ordinary," or "preferable" for all other cylinders of the drive motor. This also applies to described cylinder assemblies. This applies accordingly to embodiments relating to a piston, in particular to drive pistons and working pistons, unless explicitly excluded. Brief description of the drawings

[0068] Fig. 1 Figure 1 shows a simplified schematic sectional view of a front view of an embodiment of the drive motor according to the invention, comprising a drive piston unit in a first and second cylinder, a first working cylinder unit and a drive unit. Fig. 2shows a second working cylinder unit and the drive unit of the in Fig. 1 Drive motor shown in a rear view. Fig. 3 shows a side view of the drive unit of the in Fig. 1 and 2 shown drive motor. embodiment(s) of the invention

[0069] One embodiment of the drive motor according to the invention is described in more detail below with reference to the drawings.

[0070] The in the Figures 1 to 3The illustrated embodiment of the drive motor according to the invention comprises a first circular arc-shaped cylinder 9 with a first drive piston 9 movably arranged therein, and a second circular arc-shaped cylinder 10 with a second drive piston 10 movably arranged therein. The two drive pistons 3, 4 shown move in opposite directions within the cylinders 9, 10. The first drive piston 3 travels a stroke from a position 12', which has a minimum distance to an upper end of the first cylinder 9 (upper piston position 12'), to a position 12, which has a maximum distance to the upper end of the first cylinder (lower piston position 12).The second drive piston accordingly travels in the opposite direction, from a position 11', which has a maximum distance to the upper end of the second cylinder 10 (lower piston position 11'), to a position 11, which has a minimum distance to the upper end of the second cylinder 10 (upper piston position 11). The two drive pistons 3, 4 are connected by means of a circular arc-shaped connecting rod 13 and thus form a drive piston unit 100.

[0071] The first drive piston 3 and the second drive piston 4, as well as the cylinders 9 and 10, are identical in construction and arranged opposite each other in a cross-sectional view of the drive motor. The two cylinders 9 and 10 are designed as arc-shaped tubes, each featuring an upper screw connection 18 at an upper position 16 and a lower screw connection 19 at a lower position 17. The two cylinders 9 and 10 can be screwed together and / or to a housing (not shown) of the drive motor. Any other connection of the two cylinders 9 and 10 to each other and / or to the housing is also possible.

[0072] In each of the two cylinders 9, 10, two chambers are formed by means of the driving pistons 3, 4. A first chamber 1, 2 is located above the driving pistons 3, 4, and a second chamber 14, 23 is located below them. The first chamber 1, 2 is designed as a pressure chamber 1, 2 and includes a fluid inlet 5, 6 and a fluid outlet 7, 8 for the supply and discharge of a first fluid. The second chamber 14, 23 of the two cylinders 9, 10 contains a second fluid that differs from the first fluid (indicated by the dotted area below the driving pistons 3, 4).

[0073] The drive pistons 3, 4 are sealed against the pressure chambers 1, 2 in the usual manner, for example by means of suitable piston rings. A passage 15 of the push rod 13 from the first to the second cylinder 9, 10 is designed to be fluid-tight with respect to the second fluid.

[0074] The first fluid can be, in particular, compressed air, which can be used to pressurize the first chamber 1, 2 in order to trigger a forward stroke movement of the respective drive piston 9, 10. For example, if compressed air is supplied to the pressure chamber 1 of the first cylinder 9 via the fluid inlet 5, its fluid outlet 7 can be closed, allowing pressure to build up in pressure chamber 1, which causes a forward stroke movement of the first drive piston 3. Conversely, the fluid inlet 6 of pressure chamber 2 of the second cylinder 10 can be closed and its fluid outlet 8 open, so that the expanded compressed air still present in the second cylinder 10 can be expelled by the opposing movement (return stroke movement) of the second drive piston 4.

[0075] The first and second drive pistons 3, 4 are fluidically coupled via the second fluid to a first and a second working piston 43, 29 in a first and second arc-shaped working cylinder 35, 33. The second fluid can be, in particular, a hydraulic fluid, for example, hydraulic oil. For the fluidic coupling, an upper end of the first working cylinder 35 is connected to the first cylinder 9 via a first tube 20, and an upper end of the second working cylinder 33 is connected to the second cylinder 10 via a second tube 21. The lower ends of the two working cylinders 35, 33 are sealed by the respective working piston 43, 29. For this purpose, the piston can be equipped with suitable seals that are fluid-tight with respect to the second fluid.

[0076] The first working piston 43 and the second working piston 29 are identical in construction and larger than the drive pistons 9, 10, thus forming a hydraulic transmission. In particular, the working pistons 43, 29 have a larger diameter than the drive pistons. Accordingly, the diameter of the working cylinders 35, 33 is also larger than the diameter of the cylinders 9, 10 with the drive pistons 3, 4. Apart from the different sizes, the drive pistons 3, 4 and the working pistons 43, 29 have the same geometric shape.

[0077] Due to the hydraulic coupling of the two working pistons 43, 29 to the drive pistons 3, 4, the working pistons 43, 29 also move in opposite directions to each other. During a forward stroke, the first working piston 43 travels a stroke from a position 54', which is at a minimum distance to the upper end of the first working cylinder 35 (upper piston position 54'), to a position 54, which is at a maximum distance to the upper end of the first working cylinder (lower piston position 54). The second drive piston accordingly performs a return stroke, traveling a stroke from a position 27', which is at a maximum distance to the upper end of the second working cylinder 33 (lower piston position 27'), to a position 27, which is at a minimum distance to the upper end of the second working cylinder 33 (upper piston position 27).

[0078] During a forward stroke movement of the drive and working pistons 3, 4, 43, 29, hydraulic fluid is forced from the second chamber 14, 23 of the corresponding cylinder 9, 10 into the associated working cylinder 35, 33 (working stroke), during a return stroke movement of the pistons 3, 4, 43, 29, the hydraulic fluid is drawn back into the second chamber 14, 23, making it available again for a subsequent working stroke.

[0079] The first working piston 43 is connected to a first guide piston 44 by means of a first arc-shaped rack 38. The guide piston 44 is movably arranged in a first arc-shaped guide cylinder 36. In a cross-sectional view of the drive motor, the first guide cylinder 36 is arranged opposite the first working cylinder 35. Similarly, the second working piston 29 is connected to a second guide piston 30 by means of a second arc-shaped rack 37. The guide piston 30 is movably arranged in a second guide cylinder 34. The two guide pistons 44 and 30 are identical in design to the two working pistons 43 and 29.

[0080] Thus, the first working piston 43, the first guide piston 44 and the first rack 38 form a one-piece first working piston unit 430, and the second working piston 29, the second guide piston and the second rack 37 form a one-piece second working piston unit 290.

[0081] In particular, the first working and guide piston 43, 44 performs a counter-clockwise movement in the first working or guide cylinder 35, 36 and the second working and guide piston 29, 30 performs a counter-clockwise movement in the second working or guide cylinder 33, 34.

[0082] The first guide piston 44 is in a position 53' with maximum distance to an upper end of the first guide cylinder 36 (lower piston position 53') when the first working piston 43 is in its upper piston position 54' and in a position 53 with minimum distance to the upper end of the first guide cylinder 36 (upper piston position 53) when the first working piston 43 is in its lower piston position 54.

[0083] Likewise, the second guide piston 30 is in a position 28' with minimum distance to an upper end of the second guide cylinder 34 (upper piston position 28') when the second working piston 29 is in its lower piston position 27' and in a position 28 with maximum distance to the upper end of the second guide cylinder 34 (lower piston position 28) when the second working piston 29 is in its upper piston position 27.

[0084] The two guide cylinders 36, 34 are advantageously gas-permeable at their upper and lower ends, so that, for example, air contained in the guide cylinders 36, 34 is not compressed. This allows the guide pistons 44, 30 to move freely within the guide cylinders 36, 24, apart from any friction.

[0085] The two working cylinders 35, 33 and the two guide cylinders 36, 34 are arc-shaped and shorter than the cylinders 9, 10. In particular, the lengths of the cylinders 3, 4 and the lengths of the working cylinders 35, 33 can be designed according to the different cylinder diameters such that both have the same volume between the upper piston positions 12', 11, 54', 27 and the lower piston positions 12, 11', 54, 27'.

[0086] The first working piston unit 430 forms a first working cylinder unit 431 with the first working and guide cylinder 35, 36 and the second working piston unit 290 forms a second working cylinder unit 291 with the second working and guide cylinder 33, 34.

[0087] In this configuration, the first working cylinder 35 and the first guide cylinder 36 are connected by means of the first screw connection 26, and the second working cylinder 33 and the second guide cylinder 34 are connected by means of the second screw connection 26. Any other connection between the working and guide cylinders 35, 33, 36, 34 is equally possible. The working cylinder units 431, 291 can be suitably mounted / integrated in the housing (not shown) of the drive motor. The housing of the drive motor can, for example, also be a cylinder block in which all circular arc-shaped cylinders 9, 10, 33–36 are integrated as circular arc-shaped bores.

[0088] The drive motor further comprises a shaft 41 on which a drive element 400 is arranged. The shaft 41 includes two unspecified shaft end sections which can be connected to a driven machine by means of suitable connecting / coupling elements. The shaft can also be supported in the housing (not shown) of the drive motor 41.

[0089] The two working cylinders 35, 33 and the two guide cylinders 36, 34 are arranged at the same radial distance from the shaft 41. The first working cylinder 35 is located axially to the side of / behind the second guide cylinder 34, and the second working cylinder 33 is located axially to the side of / in front of the first guide cylinder 36. In this way, the first and second working cylinder units 431, 291 are arranged one behind the other axially to the shaft 41.

[0090] Furthermore, in a cross-sectional view of the drive motor, the first cylinder 9 with the first drive piston 3 and the second cylinder 10 with the second drive piston 4 are arranged opposite each other and at the same radial distance from a central axis that runs parallel to the shaft 41. In this case, the two cylinders 9 and 10 with the drive piston unit 100 are arranged above the two working cylinder units 431 and 291.

[0091] In the illustrated embodiment, the drive element 400 comprises two annular freewheels 39, 40, each of which has teeth 31, 32 on one end face of its outer rings (not shown). The freewheels 39, 40 are each connected to the shaft 41 by means of an inner ring (not shown), which may also have teeth. The freewheels 39, 40 of the drive element 400 are identical in construction.

[0092] The outer and inner rings of the two freewheels 39, 40 can lock against each other (drive mode) or run freely (freewheel mode). In particular, the inner surfaces of the freewheels 39, 40 can be connected to the shaft 41 in such a way that they run freely or lock in the same direction.

[0093] The outer ring of the first freewheel 40 is operatively connected to the first working piston unit 430 via a first gear 50. Similarly, the outer ring of the second freewheel 39 is operatively connected to the second working piston unit 290 via a second gear 49. Both gears 50 and 49 can each be mounted in the housing (not shown) of the drive motor by means of a gear shaft 48 and 47, respectively. The first gear 50 is arranged between the first arc-shaped rack 38 and the outer ring of the first freewheel 40, and its teeth 46 engage with teeth on the first rack 38 and with teeth 32 on the face of the outer ring of the first freewheel 40.The second gear is accordingly arranged between the second arc-shaped rack 37 and the outer ring of the second freewheel 39 and engages with its teeth 45 in a toothing of the second rack 37 as well as in the toothing 31 on the face of the outer ring of the second freewheel 39.

[0094] The first working cylinder unit 431 is driven by the first drive piston 3, and the second working cylinder unit 291 by the second drive piston 4. A reciprocating motion of the first working piston 43 induced by the first drive piston 3 causes a rotary reciprocating motion of the first freewheel 40, and a reciprocating motion of the second working piston 29 causes a counter-rotating reciprocating motion of the second freewheel 39. In this way, for example, a forward stroke of the first and second working pistons 43 and 29, induced by a corresponding forward stroke of the associated drive piston 3 and 4, can cause a continuous rotational movement of the shaft 41.

[0095] A force induced by the drive pistons 3, 4 and amplified by the hydraulic transmission of the working pistons 43, 29 is transmitted tangentially to the outside of the freewheels 40, 39 via the circular arc-shaped racks 38, 37 and the gears 50, 49. The freewheels then convert this force into a torque on their inside surface. This torque is transmitted to the shaft 41 via the inside surface of the locking freewheel 40, 39, which is connected to the shaft 41. The force can be transmitted to the shaft 41, for example, first via the inside surface of the first freewheel 40 and subsequently, during the counter-rotation, via the inside surface of the second freewheel 39.

[0096] Overall, the force generated by the respective pre-stroke movement of the drive pistons 3, 4 and amplified by the working pistons is introduced tangentially into the drive element 400 consisting of the two freewheels 40, 39 in such a way that it transmits a torque in the same direction to the shaft 41.

[0097] The tangential motor described using the exemplary embodiment enables high efficiency with simultaneously high torque across the entire speed range of the motor due to its mechanical and fluidic properties. Reference symbol list:

[0098] 1, 2 first chamber, pressure chamber 3, 4 first / second drive piston 5, 6 fluid inlet 7, 8 fluid outlet 9, 10 first / second cylinder 12', 11 upper piston position first / second drive piston 12, 11' lower piston position first / second drive piston 13 pushrod 14, 23 second chamber 15 pushrod passage 16, 17 cylinder connection 18, 19 cylinder connection position 20, 21 tube 26, 25 connection first / second working and guide cylinder 54', 27 upper piston position first / second working piston 54, 27' lower piston position first / second working piston 53, 28' upper piston position first / second guide piston 53', 28 lower piston position first / second guide piston 43, 29 first / second working piston 44, 30 first / second guide piston 32, 31 toothing on first / second freewheel 35, 33 first / second working cylinder 36, 34 first / second guide cylinder 37, 38 first / second rack 40, 39 first / second freewheel 41 shaft 46, 45 toothing first / second gear 48,47 first / second gear shaft 50, 49 first / second gear 100 drive piston unit 400 drive element 430, 290 first / second working piston unit 431, 291 first / second working cylinder unit,

Claims

1. A drive motor comprising a shaft (41) on which a drive element (400) is arranged, a first cylinder (9) with a first drive piston (3) movably arranged therein, and a second cylinder (10) with a second drive piston (4) movably arranged therein, wherein the first and second cylinders (9, 10) each have a first chamber (1, 2) and a second chamber (14, 23), wherein the first chamber (1, 2) is arranged on one side of the first or second drive piston (3, 4) and can be supplied with a first fluid and the second chamber (14, 23) is arranged on an opposite side of the first or second drive piston (3, 4) and contains a second fluid, the first drive piston (3) is fluidically coupled via the second fluid to a first working piston (43) in a first working cylinder (35), the second drive piston (4) is fluidically coupled via the second fluid to a second working piston (29) in a second working cylinder (33), wherein the first and second working pistons (43, 29) move back and forth in opposite directions in the first and second working cylinders (25, 33) and are operatively connected to the drive element (400), wherein the drive motor is configured to induce a forward stroke movement of the first working piston (43) in the first working cylinder (35) by means of a forward stroke movement of the first drive piston (3), and to induce a forward stroke movement of the second working piston (29) in the second working cylinder (34) by means of a forward stroke movement of the second drive piston (4), and wherein the operative connection between the working pistons (43, 29) and the drive element (400) is configured such that a force generated by the reciprocating movement of the working pistons (43, 29) is transmitted tangentially to the drive element (400) and the drive element (400) sets the shaft (41) in continuous rotational movement, wherein both the cylinders of the drive piston and the working cylinder are circular arc-shaped.

2. The drive motor according to claim 1, wherein the first drive piston (3) is mechanically connected to the second drive piston (4) and the drive pistons (3, 4) move back and forth in opposite directions in the two cylinders (9, 10), wherein the drive motor is configured to induce a return stroke movement of the second drive piston (4) during a forward stroke movement of the first drive piston (3), thereby conveying the second fluid from the second working cylinder (33) into the second chamber (23) of the second cylinder (4), and to induce a return stroke movement of the first drive piston (3) during a forward stroke movement of the second drive piston (4), thereby conveying the second fluid from the first working cylinder (35) into the second chamber (14) of the first cylinder (3).

3. The drive motor according to claim 1 or 2, wherein the movements of the drive pistons (3, 4) in the cylinders (9, 10) are such that when the first drive piston (3) of the first cylinder (9) is at a position with a minimum distance to an upper end (12') of the first cylinder (9), the second piston (4) in the second cylinder (10) is at a position with a maximum distance from an upper end (11) of the second cylinder (10), and / or the movements of the working pistons (29, 43) in the working cylinders (35, 33) are such that, when the first working piston (29) is at a position with a minimum distance to an upper end (54') of the first working cylinder (35), the second working piston (24) in the second working cylinder (33) is at a position with a maximum distance from an upper end (27) of the second working cylinder (33).

4. The drive motor according to claim 3, wherein when the first or second drive piston (3, 4) is at a position with a minimum distance to the upper end (12') of the first or second cylinder (9, 10), the first or second working piston (43, 29) is located at a position with a minimum distance to the upper end (54') of the first or second working cylinder (35), respectively, and when the first or second drive piston (3, 4) is at a position with maximum distance from the upper end (12') of the first or second cylinder (9, 10), the first or second working piston (43, 29) is located at a position with maximum distance from the upper end (54') of the first or second working cylinder (35).

5. The drive motor according to claim 3 or 4, wherein the first working cylinder (35) is connected at its upper end (54') to the second chamber (14) of the first cylinder (9) and is closed at its lower end (54) by the first working piston (43), and wherein the second working cylinder (33) is connected at its upper end (27) to the second chamber (23) of the second cylinder (4) and is closed at its lower end (27') by the second working piston (29).

6. The drive motor according to any one of the preceding claims, wherein the two working pistons have a larger diameter than the two drive pistons.

7. The drive motor according to any one of the preceding claims, wherein the drive element (400) comprises a first freewheel (39) and a second freewheel (40), and the first working piston (29) is operatively connected to an outer side of the first freewheel (39) and the second working piston (43) is operatively connected to an outer side of the second freewheel (40).

8. The drive motor according to claim 7, wherein inner sides of the freewheels (39, 40) are each connected to the shaft (41) such that they freewheel or lock in the same direction in order to set the shaft (41) in continuous rotational motion, and the operative connections of the working pistons (29, 43) to the outer side of the first and second freewheels (39, 40) are formed such that a reciprocating movement of the first working piston (29) causes a rotary reciprocating movement of the first freewheel (39) and a reciprocating movement of the second working piston (43) causes an oppositely directed rotary reciprocating movement of the second freewheel (38).

9. The drive motor according to claim 7 or 8, wherein the operative connection of the working pistons (29, 43) to the freewheels (39, 40) is formed by means of a toothing.

10. The drive motor according to any one of claims 7 to 9, wherein the first working piston (29) is connected to a first toothed rack (37) and the second working piston (43) is connected to a second toothed rack (38), the outer side of the first freewheel (39) has a first toothing (31) on its front side and the outer side of the second freewheel (40) has a second toothing (32) on its front side, and wherein the operative connection of the first working piston (29) to the first freewheel (39) is formed via a first gearwheel (49) and the operative connection of the second working piston (43) to the second freewheel (40) is formed via a second gearwheel (50), wherein the first gearwheel (49) is arranged between the first toothed rack (38) and the first toothing (31) of the first freewheel (39) and the second gearwheel (50) is arranged between the second toothed rack (37) and the second toothing (32) of the second freewheel (40).

11. The drive motor according to claim 10, wherein a ratio, expressed in degrees of angle, of the maximum possible circular arc movements of the push rod (13) or the first and second toothed rack (38, 37) and the maximum circular arc movement of the freewheels (39, 40) transmitted to the outer side, expressed in degrees of angle, is greater than 1, preferably greater than 1.1 and more preferably greater than 1.25.

12. The drive motor according to claim 10 or 11, wherein the first toothed rack (38) is additionally connected to a first guide piston (44) which is movably arranged in a first guide cylinder (36) and moves in the opposite direction to the first working piston (43), and the second toothed rack (37) is additionally connected to a second guide piston (30) which is movably arranged in a second guide cylinder (34) and moves in the opposite direction to the second working piston (43).

13. The drive motor according to claim 12, wherein the first guide cylinder (36), in a cross-sectional view of the internal combustion engine, is arranged opposite the first working cylinder (35) and the second guide cylinder (34), in a cross-sectional view of the internal combustion engine, is arranged opposite the second working cylinder (33).

14. The drive motor according to claim 12 or 13, wherein the two working cylinders (35, 33) and the two guide cylinders (36, 34) are arranged at the same radial distance from the shaft (41).

15. The drive motor according to any one of claims 12 to 14, wherein the first working cylinder (35) is arranged in the axial direction of the shaft next to the second guide cylinder (34) and the second working cylinder (33) is arranged in the axial direction of the shaft (41) next to the first guide cylinder (36).

16. The drive motor according to any one of the preceding claims, wherein the first and second cylinders (3, 4), in a cross-sectional view of the internal combustion engine, are arranged opposite each other and at the same radial distance from a central axis that runs parallel to the shaft (41).

17. A method for operating a drive motor according to any one of the preceding claims, comprising the steps of: a) applying a first fluid to a first chamber (1, 2) on one side of a drive piston (3, 4) in a cylinder (9, 10) to generate a forward stroke movement of the drive piston (3, 4); b) inducing a forward stroke movement of a working piston (43, 29) in a working cylinder (35, 33) by means of a fluid connection between the drive piston (3, 4) and the working piston (43, 29) via a second fluid; c) driving a shaft (41) of the drive motor by means of a drive element (400) which is mechanically connected to the working piston (43, 29).

18. A machine, motor vehicle, aircraft or ship comprising at least one drive motor according to any one or more of claims 1 to 16.

Images