SE1050347A1 - Power transmission device and method of torque transmission - Google Patents

Abstract

ABSTRACT The present invention relates to a torque/power transfer device (1, 1', 1",1"', 1""), comprising a main frame (3), a driving crankshaft (2), a drivencrankshaft (9), and a pulley system. The device is characterized in that itcomprises at least two pulley systems (10a, 10b). Each pulley systemcomprises at least one stationary pulley (11a, 12a 13a; 11b 12b 13b), whichis stationary re|ative to the main frame (3), at least one movable pulley (14a,15a, 16a; 14b, 15b, 16b), which is movable re|ative to the main frame (3), afirst wire (7a, 7b), connected to an eccentric point (Ei) of the drivingcrankshaft (2) and running over the at least one stationary pulley (11a, 12a,13a; 11b, 12b, 13b) and the at least one movable pulley (14a, 15a16a; 14b,15b, 16b), and a second wire (8a, 8b), operatively connected to the at leastone movable pulley at one end and to an eccentric point (Eo) of the drivencrankshaft (9) at its other end. (Fig 1)

Description

A TORQUE TRANSFER DEVICE AND A METHOD FOR TRANSFERRINGA TORQUE TECHNICAL FIELD The present innovation relates to a torque or power transfer devicecomprising a main frame, a driving crankshaft, a driven crankshaft, and apulley system.

The present invention further relates to a method for transferring a torqueprovided by a driving crankshaft to a driven crankshaft.

BACKGROUND ARTTorque/power transfer systems are well known in the art. For example, EP2159 448 describes a pulley driver system comprising an end|ess belt trained around a driving pinion and a driven pulley.

SUMMARY OF THE INVENTION A general object of the present innovation is to provide a device and amethod for transferring a shortened working distance through the system inrelation to the prior art as stated above.

This is in accordance with one example of the invention provided by meansof a torque/power transfer device, comprising a main frame, a drivingcrankshaft, a driven crankshaft, and a pulley system. The device ischaracterized in that it comprises at least two pulley systems. Each pulleysystem comprises at least one stationary pulley which is stationary relative tothe main frame, at least one movable pulley, which is movable relative to themain frame, a first wire connected to an eccentric point (Ei) of the drivingcrankshaft and running over the at least one stationary pulley and the atleast one movable pulley, and a second wire operatively connected to the atleast one movable pulley at one end and to an eccentric point (Eo) of thedriven crankshaft at its other end.

The dimension of the driving crankshaft and the number of stationary andmovable pulleys determines the dimensions of the driven crankshaft in thetransfer device.

The inclusion of at least two pulley systems of the torque/power transferdevice makes it possible to provide high forces in confined spaces. Thepulley systems continuously work one at a time, each pushing the drivencrankshaft to a 180° rotation so as to together push the driven crankshaft afull rotation 360° comparison to conventional systems known today so as to provide the same Thereby, the working distance can be shortened in efficiency.

Thus, the torque transfer device is capable of providing an increased forceapplied pulling at the eccentric point of the driven crankshaft, while retainingthe rotation speed as compared to that of the driving crankshaft. This isparticularly advantageous and of paramount importance when driving anelectric generator because of the synchronisation and harmony in thesystem. ln this context, a “pulley” is understood to be rotatable relative to anyarrangement carrying it. Hence, a “moveable pulley” means that therotational axis of the pulley is movable. The term “pulley” should beunderstood to encompass any structure which is capable of deflecting a wire.Hence, a pulley as understood herein may have the form of a drum, sheaveor wheel. The pulley may, but need not, have a circumferential groove for receiving the wire.

The term ”“crankshaft”” should be understood as encompassing any structurecapable of transferring a rotary or elliptical motion into a reciprocating linear motion and vice versa.

A “wire may be any type of wire, string or even a blended rod, capable oftransferring a tension force, but effectively not a compressive force, in itslongitudinal direction.

The “main frame” may be a frame, housing or any structure effectivelyproviding a support for the stationary pulleys.

The first wires may be attached to the main frame, to the movable pulley or toa movable sub frame to which the movable pulley is attached in dependenceof the configuration of the pulleys.

The second wires may be attached to the movable pulley or to a movablesub frame to which the movable pulley is attached. lt may be advantageous if the pulley systems are balanced, i.e. presentapproximately the same weight and frictiona| resistance. Therefore, in oneexample, the same material is used in all pulleys. ln accordance with one option, a first radial distance between the eccentricpoint of the driving crankshaft and a rotational centre of the driving crankshaftmay be larger than a second radial distance between the eccentric point ofthe driven crankshaft and a rotational centre of the driven crankshaft. Thelever of the driven crankshaft may have a rotational or an elliptical rotarymotion. The length of the lever, of the driven crankshaft (9), is in oneexample 0 < 2Ro < 1 meter. ln accordance with one option, the movable pulley(s) of each pulley systemmay be arranged on a respective movable sub frame, which is movable relative to the main frame. ln one option, each pulley system may comprise at least two stationarypuHeys. ln one option, each pulley system may comprise at least two movable puHeys.

The movable pulleys may be movable in a substantially vertical direction.

The invention further comprises a torque/power transfer system, comprisinga torque/power transfer device as described above and an electric generatorconnected to the driven crankshaft. Alternatively, the driven crankshaft isused as a tool for application on any type of axes that needs torque/power for rotation.

The torque/power transfer system may further comprise a power source inthe form of a drive motor or a turbine arranged operatively connected to thedriving crankshaft. The motor may be driven by e.g. electricity, fossil fuel orrenewable fuel, etc. The turbine may be driven by e.g. wind, steam or waterflow, etc.

The present invention also comprises a method for transferring a torque. Themethod comprises: The invention further comprises a method for transferring a torque/power.The method comprises: - providing an incoming rotary motion on a driving crankshaft; - providing a pair of pulley systems, each comprising: at least one stationarypulley, which is stationary relative to a main frame, and at least one movablepulley, which is movable relative to the main frame, a first wire, connected toan eccentric point of the driving crankshaft (2) and running over the at leastone stationary pulley and over the at least one movable pulley, and a second wire, operatively connected to the at least one movable pulley and to aneccentric point of the driven crankshaft (9); and - causing the driving crankshaft (2) to alternately pull on the pulley systemsso as to provide motion to the respective at least one movable pulley to pullon the driven crankshaft (9).

The driven crankshaft may be caused to drive an electric generator or a toolfor application on any type of axes that need torque/power for rotation.

BRIEF DESCRIPTION OF THE DRAWINGSFig. 1 schematically illustrates a first embodiment of torque/power transfersystem 1.

Fig. 2 schematically illustrates a second embodiment of torque/powertransfer system 1'.

Fig. 3 schematically illustrates a first embodiment of torque/power transfersystem assembly 1 Fig. 4 schematically illustrates a second embodiment of torque/powertransfer system assembly 1 DETAILED DESCRIPTION Fig. 1 schematically illustrates a torque/power transfer device 1 according toa first embodiment of the present disclosure.

An incoming crankshaft 2 is connected to a power source 21, arranged toprovide a rotary motion to the incoming crankshaft 2. The power source is forexample an electric motor a combustion engine, or a turbine (driven by e.g. wind, water, steam, photolytic). The incoming crankshaft 2 has a centre of rotation Ci, and an eccentric point Ei, which is at a radial distance Ri from the centre of rotation Ci.

The torque/power transfer device 1 further comprises a first pulley system10a and a second pulley system 10b. ln the illustrated example, each pulleysystem comprises one stationary pulley 11a, 11b and one movable pulley14a, 14b. Each pulley system comprises at least one stationary pulley 11a,11b and at least one movable pulley14a, 14b.

The stationary pulley11a of the first pulley system 10a has a radii r1. , 11bhave first radii r1. The stationary pulley 11b of the second pulley system 10bhas a second radii r7. Typically, but not necessarily, the first radii r1 would beequal to the second radii r7. The movable pulley 14a of the first pulley system10a has a first radii r4. The movable pulley 14b of the second pulley system10b has a second radii r10. Typically, but not necessarily, the fist radii r4 would be equal to the second radii r10.

The torque/power transfer device may further comprise a main frame 3, towhich the incoming crankshaft 2 may be rotatable mounted. Further, thestationary pulleys11a, 11b may be attached to the main frame 3. Themovable pulley 14a, 14b of each pulley system 10a, 10b may be attached toa respective sub frame 4a, 4b, which is movable relative to the main frame 3, which will be described in detail below. ln the shown example, a first end of a first wire 7a, 7b for each pulley system10a, 10b is in attached to the eccentric connecting point Ei of the incomingcrankshaft 2 A second end of each respective first wire 7a, 7b is in theshown example connected to the main frame. Each first wire 7a, 7b isarranged to turn over its associated stationary pulley 11a, 11b and itsassociated movable pulley such that the movable pulley 14a, 14b is movedtowards the stationary pulley 11a, 11b when the first wire 7a, 7b is pulled at its first end and vice versa. The movement of the wire may be assisted by aguide arrangement S.

As stated above, in the shown example the first end of each respective firstwire 7a, 7b is attached to the attachment point Ei. ln accordance with thisexample, the first wires 7a, 7b may be formed by a single wire having aconnecting arrangement at Ei Alternatively, the first ends of the respectivefirst wires are attached to different attachment points at the incomingcrankshaft. ln the example wherein the first wires 7a, 7b are attached to thesame connecting point Ei, the pulley system 10a, 10b will operate in counterphase, i.e. when the movable pulley of the first pulley system is movingtowards its associated stationary pulley (the first pulley system is lifted) thenthe movable pulley of the second pulley system is moving in a direction apartfrom its associated stationary pulley (the second pulley system is lowered).Accordingly, the rotational movement of the crankshaft 2 provides acontinuous reciprocating movement of the movable pulleys 14a, 14b of the first and second pulley systems 10a, 10b.

Further, the second end may for example be connected to the movable frame4a, 4b instead of in the main frame. This may be applicable in a case wherethe device involves two stationary pulleys and only one movable pulley ormore generally in a case wherein there is an odd number of pulleys in the pulley system.

An outgoing crankshaft 9 is connected to a power drain 20, which may be anelectric generator. The outgoing crankshaft 9 has a centre of rotation Co, andan eccentric point Eo, which is at a radial distance Ro from the centre ofrotation Co. The optimal theoretical distance of the lever of 9 outgoingcrankshaft (between Co and Eo) lies somewhere in between 0 < 2Ro < 1 meter.

A lever system x comprises one second wire 8a, 8b for each pulley system.Each second wire is in the illustrated example connected to the eccentricconnecting point Eo of the outgoing crankshaft 9 at one end and to themovable pulley 14a, 14b (or movable frame 4a, 4b if any) of its associatedpulley system 10a, 10b at its other end. Thereby, as the movable pulleys14a, 14b (or frame 4a,4b) perform the reciprocating, counter-phasemovement, the respective second wires 8a, 8b will pull alternately on theoutgoing crankshaft 9 thereby causing it to rotate.

The second wires 8a, 8b may be formed by a single wire having a connecting arrangement at Eo.

The pulley systems 10a, 10b may be arranged such that the movement ofthe moveable pulleys 14a, 14b and any sub frame 4a, 4b takes place in asubstantially vertical direction Dva, Dvb. The operation of the torque transferdevice 1 will now be described more in detail with reference to an example in accordance with this arrangement.

Starting from a position where a first pulley system 10a is at its lowermostpoint, and the incoming crankshaft 2 rotating in a clockwise direction, thedevice 1 will operate as follows. An incoming torque/power Ti will provide aforce on the first wire 7a. During the 180 degrees of rotation, the first wire 7awill be pulled 2Ri. With the system as illustrated in Fig 1 having a singlemovable pulley, providing an advantage of 2, the movable pulley 14a will belifted a distance corresponding 2Ri/2 = Ri. The force provided on theincoming crankshaft will be supplemented by the force provided by the massof the movable pulley 14b (and the frame 4b, if any) which will be free to fallby gravity.

With the movable pulley 14a is being lifted, the second wire 8a will be pulledto provide a force acting upon the outgoing crankshaft and the number of pulleys present device (actually the advantage provided by the pulley system) according toadvantage = Ri/Ro.

Typically, the pulley system 10a, 10b should be as identical as possible, i.e.having the same weight and measurements. A plurality of deflection pulley Smay be provided as illustrated to ensure that the wires 7a, 7b; 8a, 8b pullingon the crankshafts 9, 2 pull in optimal directions.

Fig 2 schematically illustrates a second embodiment of a torque/powertransfer device 1", wherein each pulley system 10a, 10b comprises aplurality of stationary pulleys and a plurality of movable pulleys. ln thisembodiment the number of stationary pulleys is equal to the number ofmovable pulleys. The movable pulleys are mounted substantially along a lineon a common sub frame 4a. The stationary pulleys are also mounted along aline on the main frame. The respective first wires 7a turn around all the pulleys alternatively on a stationary pulley and alternatively on a movable pulley. ln the figure, each pulley system comprises six pulleys, tree of which 11a12a, 13a; 11b, 12b, 13b being stationary and three of which 14a, 15a, 16a;14b, 15b, 16b being movable. The stationary pulleys have radii r1, r2, r3; r7,r8, r9, where e.g. r1 = r7; r2 = r8 and r3 = r9. The movable pulleys have theradii r4, r5, r6; r10, r11, r12, respectively, where e.g. r4 = r10; r5 = r11 and r6 = r12.With six pulleys in each pulley system, this embodiment would provide an advantage o 6. Hence Ro would be Ri/6.

Fig. 3 schematically illustrates a third embodiment of a torque/power transferdevice assembly 1"', where three torque/power transfer devices 1 arearranged to act on a common single outgoing crankshaft 9. Eachtorque/power transfer device 1 will be connected to a respective powersource 21 and arranged to pull 120 degrees on the outgoing crankshaft 9.Such a device 1" would typically require some further coordination mechanism to provide a drive scheme. lt is envisaged that a drive schemewould allow for the torque/power transfer devices 1 to operate two by two,with the third torque/power transfer devices 1 being at rest. Hence eachtorque/power transfer device 1 would have an operating cycle of 120 degrees work stroke; 120 degrees return stroke and 120 degrees rest.

Fig. 4 schematically i||ustrates a fourth embodiment of a torque/powertransfer device assembly 1"",where torque/power transfer devices 1 arearranged to act on a common single outgoing crankshaft 9. Eachtorque/power transfer device 1 will be connected to a respective powersource and arranged to pull 90 degrees on the outgoing crankshaft 9.Analogous to the device 1" of Fig. 3 each torque/power transfer device 1would have an operating cycle of 90 degrees work stroke, 90 degrees returnstroke and 180 degrees rest.

The outgoing crankshaft is in one example connected to an electric generatoror connected to use as a tool for application on any type of axes that needstorque/power for rotation.

The pulleys may be mounted on separate geometric axes as illustratedherein. ln the alternative, a pair of stationary or movable pulleys may bemounted on a common geometric axis. ln such case, it may beadvantageous to provide each pulley with a separate bearing system, suchthat the individual pulleys rotate independently of each other. lt is possible to provide embodiments with the same number of stationary andmovable pulleys in each pulley system. However, it is also possible toprovide embodiment with more or fewer stationary pulleys than movable puHeys. lt is preferred to use pulley and wire materials which minimize friction and Wear. 11 lt is preferred that the effective radius Ro of the outgoing crankshaft be madeas small as possible. The length of the lever, = Ro should be; 0 < 2Ro < 1 meter.

Claims (1)

1. A torque/power transfer device (1, 1', 1", 1”a main frame (3), ', 1 comprising a driving crankshaft (2), a driven crankshaft (9), and a pulley system , characterized in that it comprises at least two pulley systems (10a, 10b), each pulley system comprising at least one stationary pulley (11a, 12a 13a; 11b 12b 13b), which isstationary relative to the main frame (3), at least one movable pulley (14a, 15a, 16a; 14b, 15b, 16b), which is movable relative to the main frame (3), a first wire (7a, 7b), connected to an eccentric point (Ei) of the drivingcrankshaft (2) and running over the at least one stationary pulley (11a,12a, 13a; 11b, 12b, 13b) and the at least one movable pulley (14a, 15a16a; 14b, 15b, 16b), and a second wire (8a, 8b), operatively connected to the at least onemovable pulley at one end and to an eccentric point (Eo) of the drivencrankshaft (9) at its other end. The torque/power transfer device as claimed in claim 1, wherein a firstradial distance (Ri) between the eccentric point (Ei) of the drivingcrankshaft (2) and a rotational centre (Ci) of the driving crankshaft (2) islarger than the a second radial distance (Ro) between the eccentricpoint (Eo) of the driven crankshaft (9) and a rotational centre (Co) of the driven crankshaft (9). 13 The torque/power transfer device as claimed in any one of thepreceding claims, wherein the respective movable pulleys (14a, 15a,16a; 14b, 15b, 16b) are arranged on a movable sub frame (4a, 4b),which is movable relative to the main frame (3). The torque/power transfer device as claimed in any one of thepreceding claims, wherein each pulley system (10a, 10b) comprises atleast tvvo stationary pulleys (11a, 12a, 13a; 11b, 12b, 13b). The torque/power transfer device as claimed in any one of thepreceding claims, wherein each pulley system (10a, 10b) comprises atleast two movable pulleys (14a, 15a, 16a; 14b, 15b, 16b). The torque/power transfer device as claimed in any one of thepreceding claims, wherein the movable pulleys (14a, 15a, 16a; 14b, 15b, 16b) are movable in a substantially vertical direction (Dva, Dvb) An mechanical transfer system, comprising a torque/power transferdevice (1, 1', 1", 1")', as claimed in any one of the preceding claims,wherein the driven crankshaft is connected to an electric generator (20)or is used as a tool for application on any type of axes that needtorque/power for rotation. The mechanical transfer system as claimed in claim 6, wherein thedriving crankshaft (2) is connected to a power source (21) in the form ofa drive motor or a turbine. A method for transferring a torque/power, the method comprising: - providing an incoming rotary motion on a driving crankshaft; 10. 14 - providing a pair of pulley systems, each comprising: at least onestationary pulley, which is stationary relative to a main frame, and at leastone movable pulley, which is movable relative to the main frame, a firstwire, connected to an eccentric point of the driving crankshaft (2) andrunning over the at least one stationary pulley and over the at least onemovable pulley, and a second wire, operatively connected to the at leastone movable pulley and to an eccentric point of the driven crankshaft (9); - causing the driving crankshaft (2) to alternately pull on the pulleysystems so as to provide motion to the respective at least one movablepulley to pull on the driven crankshaft (9). The method as claim in 9, wherein the driven crankshaft (9) is causedto drive an electric generator or is connected to a tool for application onany type of axes that needs torque/power for rotation.