CA2313484A1 - Drive mechanism and torque sensor, and method for the production thereof - Google Patents
Drive mechanism and torque sensor, and method for the production thereof Download PDFInfo
- Publication number
- CA2313484A1 CA2313484A1 CA002313484A CA2313484A CA2313484A1 CA 2313484 A1 CA2313484 A1 CA 2313484A1 CA 002313484 A CA002313484 A CA 002313484A CA 2313484 A CA2313484 A CA 2313484A CA 2313484 A1 CA2313484 A1 CA 2313484A1
- Authority
- CA
- Canada
- Prior art keywords
- torque
- drive device
- rotor
- poles
- spindle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62M—RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; POWERED PROPULSION OF SLEDGES OR SINGLE-TRACK CYCLES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES
- B62M6/00—Rider propulsion of wheeled vehicles with additional source of power, e.g. combustion engine or electric motor
- B62M6/40—Rider propelled cycles with auxiliary electric motor
- B62M6/55—Rider propelled cycles with auxiliary electric motor power-driven at crank shafts parts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62J—CYCLE SADDLES OR SEATS; AUXILIARY DEVICES OR ACCESSORIES SPECIALLY ADAPTED TO CYCLES AND NOT OTHERWISE PROVIDED FOR, e.g. ARTICLE CARRIERS OR CYCLE PROTECTORS
- B62J45/00—Electrical equipment arrangements specially adapted for use as accessories on cycles, not otherwise provided for
- B62J45/40—Sensor arrangements; Mounting thereof
- B62J45/41—Sensor arrangements; Mounting thereof characterised by the type of sensor
- B62J45/411—Torque sensors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62M—RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; POWERED PROPULSION OF SLEDGES OR SINGLE-TRACK CYCLES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES
- B62M6/00—Rider propulsion of wheeled vehicles with additional source of power, e.g. combustion engine or electric motor
- B62M6/40—Rider propelled cycles with auxiliary electric motor
- B62M6/45—Control or actuating devices therefor
- B62M6/50—Control or actuating devices therefor characterised by detectors or sensors, or arrangement thereof
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- Transportation (AREA)
- Force Measurement Appropriate To Specific Purposes (AREA)
- Power Steering Mechanism (AREA)
Abstract
The invention relates to an electric motor-driven supported muscular power driven drive mechanism in which the torque is measured by a torque sensor (35). Said sensor is centrally arranged in the area of the pedal axle (1) in the drive mechanism. The torque sensor is a magnetic pole type and has essentially band-shaped magnet poles (43, 53) which are displaced against one another by the torsion of a torsion section (39), whereby a magnetic value of the sensor (35) changes. As a result, a compact drive mechanism can be produced which permits a precise measurement of the muscular power torque. The sensor can be compactly constructed with the band-shaped magnet poles and can be easily produced.
Description
Drive device and torque sensor and method of producing it Technical field The invention relates to a drive device according to the preamble of Claim 1. Furthermore, the invention relates to a torque sensor according to the preamble of Claim 18 and to a method of producing it according to the preamble of Claim 24.
Prior art Muscle-power drives assisted by electromotive force are known, in particular in vehicles, e.g. in bicycles driven by foot pedals. Important factors in such drives are their spatial requirement and the detection by measurement of the [lacuna] produced by muscle power and/or of the motor torque.
Known solutions are often too heavy and too large and have an inadequate torque-measuring range or a resolution which is too inferior, or only the rotational speed or the angular velocity is used instead of a real torque measurement.
It is desirable to be able to control the output of the electric motor in such a way that its torque can be added to or superimposed on the biological force in real time and comfortably according to biomechanically optimum characteristics, so that the auxiliary force is smoothly connected to the system; this imposes corresponding AMENDED PAGE
:, - la -requirements on the accuracy and resolution of the torque sensory system.
In the already existing muscle-power-amplifying auxiliary drives of commercially available electric bicycles AMENDED PAGE
Prior art Muscle-power drives assisted by electromotive force are known, in particular in vehicles, e.g. in bicycles driven by foot pedals. Important factors in such drives are their spatial requirement and the detection by measurement of the [lacuna] produced by muscle power and/or of the motor torque.
Known solutions are often too heavy and too large and have an inadequate torque-measuring range or a resolution which is too inferior, or only the rotational speed or the angular velocity is used instead of a real torque measurement.
It is desirable to be able to control the output of the electric motor in such a way that its torque can be added to or superimposed on the biological force in real time and comfortably according to biomechanically optimum characteristics, so that the auxiliary force is smoothly connected to the system; this imposes corresponding AMENDED PAGE
:, - la -requirements on the accuracy and resolution of the torque sensory system.
In the already existing muscle-power-amplifying auxiliary drives of commercially available electric bicycles AMENDED PAGE
imposes corresponding requirement a accuracy and resolution of the torque sensory system.
In the already existing g u's~~"~ower-amplifying a in which the auxiliary drive sits in the region of the pedal bearing, the motor is usually arranged outside the pedal bearing, so that the motor spindle is parallel to or at right angles to the pedal spindle. In these known drive concepts, the problem occurs that they consist of many individual parts and therefore require a relatively large amount of space.
This results in losses in the overall efficiency, a large maintenance cost, wear, a high weight, increased susceptibility to dirt, etc.
DE-A-195 22 419 shows a gearless drive unit which is arranged coaxially to the pedal spindle and is designed for retrofitting conventional bicycles and in which a stator of an electric motor and a rotor combined with the sprocket wheel are arranged outside the pedal-bearing cartridge in an exposed position on the bicycle. The electric motor has a low rotational speed within the range of the pedal rotational speed. Rotary-measuring [sic] strips at the connecting point between crank star and sprocket wheel are used as torque sensors. The retrofit solution shown in this document has various disadvantages. The conventional bicycle frame offers little installation space in the pedal-bearing region, so that the motor width is greatly restricted as a result . The torque required for satisfactory and ample motor assistance can only be achieved by a large diameter in this type of construction, a factor which reduces the ground clearance in the pedal-bearing region.
Owing to the fact that the drive is located in the region of spray water, this results in a correspondingly high maintenance cost, increased susceptibility to dirt, and wear.
The installation of an effective seal is very complicated, since the interface of rotor and stator is on a large diameter. The torque applied by the cyclist, which torque may be highly pulsating depending on the crank position, is passed on via the rotor, mounted only on one side, and transmitted to the bicycle chain via a single transmission point. This results in large torsional stresses in the motor region, so that it is difficult to exactly maintain a uniform air gap between rotor and stator.
EP-A-0743 238 shows a drive unit for a bicycle in which a motor having a small diameter and higher rotational speed is used, for which reason transmission gearing is fitted for adapting the very low pedal-spindle rotational speed to the higher rotational speed of the motor. Since the comparatively very high cyclist torque has to be "stepped up"
via this gearing, considerable losses result. Owing to the fact that the rotational speeds of motor and drive gear are relatively high, a freewheel clutch is required for decoupling the motor during travel operation without motor assistance, otherwise a large motor braking torque results during this travel operation. Furthermore, pushing the vehicle backward is made more difficult.
Since a freewheel is fitted in the train of the force-transmission flow from pedal spindle to the output wheel for decoupling the pedals during pure motor travel operation, a back-pedalling brake can no longer be used without additional attachments. The torque is detected by a load cell at the supporting point of the gear housing, which is arranged in the drive housing.
Furthermore, w0 97/05010 shows a wheelchair having wheel-hub motors and muscle-power actuation by a handrail, a sensor being arranged between handrail and the rotor in order to detect the torque induced via the handrail.
In the most diverse applications, such as, for example, motor-driven screwdrivers, drilling machines, motor-operated drives in general and in particular motor-operated actuators or the abovementioned electromotive auxiliary drives of vehicles actuated by muscle power, it is desirable to be able to detect torque. Various mechanical torque sensors are known, which, however, often have a complicated construction and their detection principle makes integration in an fre . d -7 82 romec 'sted 8 890 shows V
_ 4 0._ electronic motor control complicated. EP-A-683 093 and EP-A-700 825 show electromechanical torque sensors in bicycles assisted by electric motor, in which the torque is AMENDED PAGE
detected via the stroke of a lever, extending transversely in the housing, and a stroke sensor. GB-A-2 312 403 shows an electric bicycle drive in which a motor with gearing and freewheel is arranged in a housing coaxially to the pedal spindle. US-A-3 938 890 shows electro-optical torque detection, which in drives which contain lubricants can result in problems with the optical detection. EP-A-682 238 shows a torque-measurement device in which a magnetic field is produced by a coil and is transmitted via two pole-pair arrangements on either side of a torsion section. The magnetic coupling of the poles, which are separated by an air gap, depends on torsion and thus on torque. The magnetic field passes into and out of the poles via an air gap.
Magnetic-field sensors are provided at the return point in order to detect the torque- or torsion-dependent change in the magnetic field. From the signal of the magnetic-field sensors, an output signal corresponding to the torque is produced in an analyzing circuit. The production of the device is expensive, since the poles are designed as pins which have to be arranged individually in apertures of the respective non-magnetic carrier, and this has to be done very precisely in order to keep the air gap between all the opposite pins as uniformly large as possible. In restricted installation conditions and with correspondingly small dimensions, such a device is complicated and expensive to produce. US-A-4 876 899 shows a torque sensor having AMENDED PAGE
continuous pole arrangements on either side of a torsion section, in which pole arrangements introduction is effected via a central coil and the outputting is effected via two lateral coils.
The object of the invention, on the one hand, is therefore to provide a motor-assisted muscle-power drive which has a simple construction, requires little space and is insensitive to dirt and spray water for applications in vehicles and the torque detection of which enables the torque produced by muscle power to be detected as far as possible free from delay and with high resolution. This object is achieved in a drive device of the type mentioned at the beginning having the characterizing features of Claim 1.
Owing to the fact that the torque-detection unit is arranged centrally in the housing and can receive the muscle-power torque directly. [sic] this results in both a compact drive arrangement and the possibility of detecting the torque with good resolution and without interference from gear units or mechanical transmission members. Furthermore, the torque-detection unit is accommodated in the housing in a protected manner.
In a preferred embodiment, the torque-detection unit comprises a sleeve which at least partly accommodates the spindle and may also be part of the rotor or be connected to the latter preferably via a transmission ring, to which the output wheel is also fastened. The torque-detection unit may AMENDED PAGE
be designed with strain gages; however, it preferably has a torque sensor having magnet poles, which are arranged on either side of a torsion section and change their relative position during torsion of the section, which results in a change in a magnetic variable, this change corresponding to the torque. A preferred field of use of the drive is in an electric bicycle.
On the other hand, the object of the invention is to provide a torque sensor which is compact and simple in construction and thus simple and inexpensive to produce and which nonetheless has a high resolution and good measuring accuracy for the torque.
The object is achieved by the characterizing features of Claim 18. The arrangement of an annular coil around the torsion member, while maintaining a simple construction, results in the possibility of a radially or axially low overall height of the sensor, and the magnetic variable is detected by a further coil arranged around the torsion member in an annular manner.
Furthermore, the object of the invention is to provide a method of producing a torque sensor having magnet poles which permits its simple and cost-effective production even in the case of a high number of poles and with very small air-gap tolerances.
This object is achieved by the characterizing features of Claim 24.
AMENDED PAGE
_ g _ Owing to the fact that first of all a ring is formed and connected to the holding parts and that only then are the poles cut out of the ring, cost-effective production results, since the poles do not have to be fastened individually to the holding parts; furthermore, due to the subsequent forming of the poles in the fitted state, the accuracy of the air gaps is determined essentially only by the cutting operation, which is preferably carried out with a laser.
The poles are preferably already preformed at a flat strip before the latter is rounded to form the ring, a factor which reduces the number of subsequent cutting operations.
Brief description of the drawings Exemplary embodiments of the invention are explained in more detail below with reference to the drawings, in which:
AMENDED PAGE
_ g _ achieve es of Claim 24.
Owing to the fact that first of all a ring formed and connected to the holding parts and that o then are the poles cut out of the ring, cost-effective roduction results, since the poles do not have to be f stened individually to the holding parts; furthermore, d to the subsequent forming of the poles in the fitted s te, the accuracy of the air gaps is determined essentia y only by the cutting operation, which is preferably car ed out with a laser.
The poles are referably already preformed at a flat strip before the atter is rounded to form the ring, a factor which reduces he number of subsequent cutting operations.
Brief description of the drawings Exemplary embodiments of the invention are explained in --~~ cn Figure 1 shows a sectional representation of a first embodiment of the drive device;
Figure 2 shows a sectional representation through a further embodiment of the drive device;
Figure 3 shows a side view of a bicycle;
Figure 4 shows a schematic diagrammatic magnetic-field torque sensor;
Figure 5 shows a schematic side view of poles and the magnetic-field introduction of the sensor of Figure 4;
Figure 6 shows a schematic plan view of a partial development of the poles of the sensor of Figure 4;
Figure 7 shows a plan view of a stamping for producing the poles of the sensor;
Figure 8 shows a ring part pushed onto two holders on a torsion section and intended for forming the poles;
Figure 9 shows a sectional representation of a drive device similar to that of Figure 1 having a magnetic-field torque sensor.
Best way of implementing the invention Figure 1 shows a drive device according to the invention in an electric bicycle in section. In this case, the pedal spindle 1 is mounted as a central spindle inside the rotor 6 of the electric motor 10, the rotor consisting of the magnetic return ring 7 having the magnets 8, the disk-shaped rotor body 6a and a sleeve part 6b, which encloses the central spindle 1 and in which the pedal spindle 1 is guided axially and radially by suitable means. However, the mounting of the pedal spindle 1 may also be modified by virtue of the fact that the pedal spindle 1 may be mounted directly in the housing 15 or partly in the housing 15 and partly in the rotor 6. The pedal cranks 4, 5 having the pedals 2, 3 (only partly shown) are fastened to the ends of the pedal spindle 1. In order to transmit the muscle-power torque, the pedal cranks 4, 5 are detachably connected to the pedal spindle 1, but a fixed connection is also conceivable.
The spindle 1 is firmly connected to the sleeve 6b at location 18, e.g. by welding. The spindle 1 is rotatably mounted in the sleeve 6b at location 19 , a . g . by means of a sliding intermediate layer. In this way, the torque of both cranks is passed into the sleeve 6b via the spindle 1 at location 18.
The drive housing 15 is firmly connected to the frame 16; if need be it may be detachably fastened or be designed as an integral frame part.
The sprocket wheel 11, which in this case serves as output wheel, is connected to the rotor 6 so as to be fixed in terms of torque, but is connected to the pedal spindle 1 in a torsionally elastic manner via the sleeve part 6b of the rotor 6. The sprocket wheel 11 sits on the sleeve part 6b of the rotor 6 on the outside of the housing 15 and is in engagement with the rear wheel of the bicycle by means of a force-transmission means 12, e.g. a chain. However, the coupling between sprocket wheel 11 and rotor 6 could also be effected in another way by the sprocket wheel sitting directly on the radially running disk-shaped rotor body 6a or by being designed as an integral part of the rotor body. The rotor 6 is in each case supported via a bearing 13, 13' both on the side of the output wheel 11 and on the other side of the pedal spindle 1. Alternatively, the rotor 6 could be mounted, for example, both in the housing 15 and on the pedal spindle 1. Rolling-contact bearings or sliding bearings are suitable as bearings for both the rotor mounting and the pedal-spindle mounting, and in the simplest case, in which no relative movement takes place between rotor and spindle, the support may be effected as a fixed connection. The bearings of the pedal spindle and of the rotor advantageously lie in one plane; but a position of the bearings relative to one another which differs therefrom is also conceivable. The electric motor 10, consisting of stator 9 and rotor 6, is arranged coaxially to the pedal spindle 1. It may advantageously be designed as a permanently excited synchronous motor, the stator 9 being firmly connected to the drive housing 15 or being provided as a housing part. A very expedient motor configuration is obtained through the use of an external rotor.
The torque-detection unit 14 is arranged centrally in the housing coaxially to the pedal spindle 1 and is assigned directly to the rotor sleeve part 6b. In this case it detects the torsion of the sleeve 6b on the basis of the muscle-power-produced torque induced in this sleeve 6b. The detection is effected, for example, by means of a torque sensor having a strain-measuring element fastened to the sleeve or preferably having a magnetic-pole sensor, as will be explained. The unit 14 is located entirely in the interior of the drive housing 15 and, in the example shown, can detect both torque on the rotor sleeve part 6b and torque on the disk-shaped rotor body 6a by means of the strain gages 31 and 32 shown. Thus, depending on the design of the motor control, both the muscle-power torque and the motor torque can be detected individually or both together by means of the rotor parts 6a, 6b, which are under torsional stress due to the torque and serve as measuring section. The torque originating from the pedal force of the cyclist is detected via the deformation of the rotor sleeve part 6b as a result of torsion and is measured and analyzed by an operatively connected, electronic sensory measuring system. If, for example, torque is transmitted by the pedals 2, 3, the torque signal obtained is processed in real time by a motor control unit 17, which may also be integrated in the drive interior, and controlled in accordance with the electric motor 10 or its torque is adapted to the instantaneous power requirement.
In this way, freewheels or clutches may be completely dispensed with, which leads to a low-wear drive unit and a correspondingly high efficiency.
Figure 2 shows, in section, a modification of the drive device integrated in the pedal-bearing region of an electric bicycle. The pedal spindle 1 is again placed as a central spindle inside the rotor 6 of the electric motor 10 and is mounted partly in the housing 15 and partly in the rotor 6.
However, this may also be achieved as in Figure 1.
The pedal cranks may again be fastened to the ends of the pedal spindle . The drive housing 15 is firmly connected to the frame; if need be it may be detachably fastened or designed as an integral frame part. In this example, the spindle 1 is provided with an annular part lc in the center, and this annular part lc is firmly connected to the sleeve 6b of the rotor 6. Here, too, a sliding intermediate layer 19 is provided between spindle and rotor. In this design, via the two torsion sections la, lb, which each form a part of the pedal spindle 1, two different torques, the torques of both cranks, are separately detected and analyzed. The sprocket wheel 11 (output wheel) again sits on the rotor 6 on the outside of the housing 15 so as to be fixed in terms of torque and is in engagement with the rear wheel of the bicycle by means of a force-transmission means 12, e.g. a chain. However, the coupling between sprocket wheel 11 and rotor 6 could also be effected in another way by the sprocket wheel sitting directly on the radially running disk-shaped rotor body 6a or by being designed as an integral part of the rotor body. The rotor 6 or respectively the pedal spindle 1 is in each case supported via a bearing 13 , 13' both on the side of the output wheel 11 and on the other side of the pedal spindle 1. Alternatively, the rotor 6 could be mounted, for example, on either side in the housing 15. Rolling-contact bearings or sliding bearings are suitable as bearings for both the rotor mounting and the pedal-spindle mounting.
The electric motor 10, consisting of stator 9 and rotor 6, is arranged coaxially to the pedal spindle 1. It is preferably designed as a permanently excited synchronous motor, the stator 9 being firmly connected to the drive housing 15 or being provided as a housing part. A very expedient motor configuration is obtained through the use of an external rotor.
The torque-detection unit is located entirely in the interior of the drive housing, consists of two parts 14a, 14b in this case and is arranged coaxially to the pedal spindle 1. Thus, depending on the design of the motor control, the torques of both cranks may be separately detected and analyzed. The torques originating from the pedal forces of the cyclist are detected via the deformation of the pedal-spindle torsion sections la, 1b, e.g. again via strain gages or magnetic-pole sensors, and are measured and analyzed by an operatively connected, electronic sensory measuring system.
By a motor-control unit 17, which is known per se and is not explained in any more detail here and which may also be integrated in the drive interior, the torque signals obtained are processed in real time and controlled in accordance with the electric motor 10 or its torque is adapted to the instantaneous power requirement. Freewheels or clutches may again be completely dispensed with, which leads to a low-wear drive unit and a correspondingly high efficiency.
Figure 3, as a side view, shows how, for example, a complete concept for a fully sprung electric bicycle 30 having the drive device 1 according to the invention may look. The main frame 25 is connected to the drive link 28 via pivot 24 and spring/damper element 21. Frame struts 4 connect the main frame 25 and seat pillar 26. The drive device 1 sits in the drive link 28. The battery container 18 forms the actual energy box, in which the charging device, the motor-control unit, removed from the drive in this example, and possible displays 23 can be accommodated. The rear wheel hub 22 may be designed with a commercially available hub gear, a derailleur gear or a combination of both.
Figure 4 shows a torque sensor which has two holding members 36 and 37, which are fastened separately from one another on a tors ion member 3 8 , a . g . a shaf t or sleeve . In this case, that region of the torsion member 38 which lies between the holding members 36 and 37 forms a torsion section, the torsion of which is determined by means of the magnet poles arranged on the holding members 36 and 37. Only some of the magnet poles 40-45 of the one holding member or 50-56 of the other holding member are shown in Figure 4, said magnet poles being fastened to the holding parts all around the torsion member. The magnet poles 40 [lacuna] are arranged so as to point toward one another, in which case they are staggered relative to one another in the example of Figure 4.
A magnetic flux is produced in the poles by a coil 48 (only intimated in Figure 4) extending in an annular manner around the holding part 36. In this case, the magnetic flux is fed from the stationary coil 48 into the poles 40 to 45 of the holding part 36 via their respective rear end regions 40' to 45'. In this case, in the example of Figure 4, the magnetic field is fed in via the coil 48 and the torsion-induced change in the magnetic flux through the poles is detected by means of a further coil 58, which is directed in an annular manner around the holding part 37 or around the poles 50-56 with their end regions 51'-55' shown. The magnetic flux is preferably introduced via an air gap in a non-contact manner, so that the torsion member 38 with the holding parts 36, 37 fastened thereto or the poles can rotate relative to the stationary coils. The torque at a rotating shaft or sleeve 38 can therefore be detected, thus, for example, at a shaft of a drive moved by muscle power or by a motor.
Figure 5 and Figure 6 show schematic representations for explaining the mode of operation of the torque sensor of Figure 4. In this case, Figure 5 shows a side view of two respective magnet poles 42, 43 and 52, 53, and Figure 6 shows a plan view of such magnet poles for explaining the magnetic flux. The torsion member 38 is again shown in Figure 5 and forms a torsion section 39 between the holding parts 36 and 37 intimated, for which purpose the torsion member may also have a zone of weakening at this location, as shown by the reduced cross section over the torsion section 39. The torsion member is shown in half vertical section above its center axis D; the other parts of the drawing, however, are only shown schematically for explaining the mode of operation together with the likewise schematic view of Figure 6. Thus the holders 36 and 37 for the magnet poles are only intimated. The coil, likewise only intimated by a pair of winding wires 48, is arranged in a yoke 47, the legs 47' of which point toward the end pieces 43' and 42' respectively of the magnet poles 42 and 43 shown. When current flows from a source 60 indicated, which feeds the coil 48, in the direction of the current-flow symbol 49, a magnetic south pole S and north pole N respectively are obtained at the yoke legs 47'. The magnetic flux produced as a result in the magnet poles 42 and 43 is shown by the broken lines F in Figure 6. In the idle state of the torque sensor, i.e.
without torsion of the torsion section 39, the magnet poles 42, 43 and 53 and 54 are located opposite one another as shown in Figure 6. In this figure, the position of the yoke legs 47' is indicated by broken lines. The annular coil 48 surrounding the holding part, with its annular yoke 47, which likewise extends around the holding part 36, produces a magnetic flux F, which essentially passes at the front end of the magnet pole 42 through the air gap d into the magnet pole 53 and from the latter again into the magnet pole 43 and back to the yoke 47. A small portion of the flux may also flow in this position via the magnet pole 53 or its end 53' and via the yoke 57 of the coil 58 into the end 54' of the magnet pole 54 and through the latter back to the magnet pole 43 and the yoke 47. This small magnetic flux produces an electric voltage in the coil 58, which in Figure 5 is also only intimated by a pair of winding wires, and this electric voltage may be amplified in an amplifier 61 and rectified in a rectifier 62. In this case, the voltage induced in the coil 58 in the idle state corresponds to the lower value of the detectable torque, since torsion of the torsion section 39 still does not occur in this idle state. If a torque which leads to torsion of the torsion section 39 is now transmitted via the torsion member 38, the holding member 36, for example, rotates relative to the holding member 37 in such a way that a movement of the magnet poles 42, 43 in the direction of arrow B in Figure 6 is obtained. The magnet poles 42 and 53 and respectively 43 and 54 are displaced relative to one another in such a way that their end faces have a slight overlap over the air gap d, a factor which leads to the magnetic flux passing increasingly via the magnet poles 53 and 54 and via the yoke 57, so that the voltage induced in the coil 58 increases . In this case, the increasing voltage in the coil 58 or after amplification and rectification at the output of the rectifier 62 is approximately proportional within the measuring range to the rotation of the torsion section 39 or to the torque induced in the torque sensor. Thus, for example, with a torque sensor of a few centimeters diameter, a torque of 1 Nm up to 300 Nm can be measured in this way with good resolution at an appropriately designed torsion section. In this case, the value of 300 Nm may produce a rotation of about 1.5° of the torsion section. If the coil 47 is fed with a voltage signal of 3.5 V and a frequency of 14 kHz, a useful signal in the coil 58 of 5 mV, which may be amplified and rectified, is obtained. The DC voltage delivered at the rectifier 62 may be delivered as a measured value for the torque to a display device or an open-loop or closed-loop control, which controls a drive for example. In a preferred type of use, the muscle-power torque at a pedal spindle or a sleeve connected to the latter is detected in said manner and used for the open-loop or closed-loop control of an electric auxiliary drive. The essentially band-shaped configuration of the magnet poles which is shown in Figure 4 permits a small overall height of the torque sensor, which is advantageous for its use in a wide variety of drives or for a wide variety of torque-measuring tasks. The feeding or the measuring of the magnetic flux by means of ring coils, as likewise shown in Figures 4-6, likewise permits the design of the torque sensor with a small diameter or a small overall height.
In this case, the embodiment shown, having a number of magnet poles completely staggered relative to one another, is only to be understood as a preferred example. The magnet poles, pointing toward one another, of the two holding parts 36 and 37 could also be staggered relative to one another to a smaller degree in the idle state or could also be exactly opposite one another. The latter case results in the maximum magnetic coupling from the coil 48 to the coil 58 when the torsion section is not rotated. Rotation of the torsion section then results in less coupling to the coil 58 and thus a signal decreasing in accordance with the torque. More than one row of magnet poles, as disclosed by EP-A-0682 238, could also be used.
The sensor described is produced according to the invention by a closed ring first of all being formed from the ferromagnetic material forming the magnet poles, this ferromagnetic material preferably being in the form of a band. This ring is now pushed onto the two ends of the non-magnetic holding parts 36, 37 and fastened there at those points where the poles are to be fastened to the holding parts. This may be effected, for example, by spot-like adhesive bonding of the ring to the holding parts 36 and 37.
The latter are fastened to the torsion member 38 at the same time or subsequently, e.g. likewise by adhesive bonding or pinning. The magnet poles are then cut out of the closed ring by a laser beam, in which case the parts of the ring which are fastened to the holding parts 36 and 37 form the magnet poles and the unfastened parts are removed as cut waste. In this case, a circumferential cut in the center of the ring separates the poles of the two holding parts from one another. The non-fastened parts of the ring which lie between the poles of each holding part are released from the poles by cuts along the lateral lines of the cylindrical ring. After the poles have been formed, they may be fastened to the holding parts in a more intensive manner by a casting compound for example. The production method described has the advantage that the magnet poles do not have to be separately formed beforehand and fastened individually to the holding parts, and that, by the fastened ring being cut with the holding parts already positioned relative to one another on the torsion member, an air gap which is uniform to an extremely accurate degree over the circumference of the torque sensor is produced, which permits corresponding accuracy and fine resolution of the torque measurement.
A modified, preferred production method is explained with reference to Figures 7 and 8. In this case, Figure 7 shows a pole strip 65 of ferromagnetic material, which has a continuous web 66 and legs 67 projecting from the web 66 in a staggered manner. The legs may also have a different length from one another. Such a strip may be produced, for example, by a stamping or cutting operation. The successive legs 67 of each side of the pole strip are then alternately bent approximately in such a way as shown schematically in Figure for the successive pole strips 42 and 43 or 52 and 53 respectively. The pole strip bent in this way is then bent into a ring, as partly shown as ring 69 in Figure 8. In this case, the actual ring is formed by the web 66, and the bent legs 67 proj ect from this ring on both sides . The pole ring 69 in this case is now pushed with its legs 67 onto the non-magnetic holding parts 36 and 37 respectively, in which case the latter, as shown in Figure 8, may be of stepped design and may be provided with slots 70 and 71, in which the legs are accommodated. In this case, Figure 8 shows the ring 69 already pushed onto the holding part 36 and shows the holding part 37 in a position that (sic] it can likewise be joined together with the ring 39. In addition, the torsion member 38 with the torsion section 39 is inserted into the holding parts 36 and 37. In this case, the bent legs 67, with their end regions projecting upward, form the end regions of the magnet poles still to be formed, as indicated for one leg by the reference numeral 43' in accordance with that of Figure 5. The legs 67 may be adhesively bonded in the slots 70 and 71 of the respective holding parts. Furthermore, the stepped part of the holding parts may be covered by a hardening casting compound after the holding parts have been pushed together, so that, of the magnet poles, only the angled end regions project radially from the holding parts 36 and 37 and the web 66 is exposed between the holding parts. After the casting compound has hardened, the circumference of the holding parts 36 and 37 may be turned or ground, so that the end regions of the magnet poles, e.g. the end region 43' , is flush with the outer surface of the holding part. After the holding parts 36 and 37 have been fixed in place on the torsion member 38 as described and the magnet-pole legs 67 have been fastened to and in the holding parts, the web 66, as already mentioned, is now cut in such a way that the individual magnet poles are formed. Thus the air gap d is formed between the opposite magnet poles by a circumferential cutting line L, e.g. by means of a laser. This air gap, for example, may have a size of 0.3 mm, which remains constant even after the cutting due to the already fixed bearings [sic] of all parts relative to one another. Furthermore, the hatched parts can be cut out by cuts through the web 66 in the axial direction, so that the magnet-pole arrangement according to Figure 4 having magnet poles opposite one another in a staggered manner is obtained. Of course, magnet poles which are not staggered relative to one another could also be obtained by appropriate shaping of the strip 65.
Figure 9 shows a drive device of a bicycle having an electromotive auxiliary drive similar to that of Figure 1, using a torque sensor as has been described with reference to Figures 4-8. In this case, the same reference numerals as used previously describe the same parts. Since the drive device is symmetrical to the longitudinal axis, essentially only the part lying above the longitudinal axis is shown and this part is also truncated toward the top in the figure, so that only part of the rotor and the housing of the output wheel can be seen. In the example shown, the pedal spindle 1 is welded to the sleeve 76 at location 75. That region of the pedal spindle which lies inside the sleeve is movably mounted relative to the sleeve by a sliding intermediate layer 19. In this way, the torque induced in the pedal spindle 1 by the pedal cranks (not shown) is transmitted to the sleeve at location 75. The sleeve at the same time forms the torsion member 38 of a torque sensor having magnet poles. For this purpose, the sleeve is designed to be thinner in the region of the torsion section 39 in order to permit torsion there on account of the muscle power induced. At its other end, the sleeve 76 is firmly connected, e.g. welded, at location 77 to a torsion-transmission ring 78. This ring is also mounted so as to slide relative to the pedal spindle. Engaging on the torsion-transmission ring 78 in a torsionally rigid manner is, on the one hand, the rotor 6, and, on the other hand, the output wheel 11 on the outside of the housing, which is a sprocket wheel for example. In this case, the ring 78 is provided with apertures 80, which are separated from one another by ribs and in which pins 81 and 82 of the rotor and the output wheel respectively engage in order to ensure the torque transmission from the torsion-transmission ring 78 to the rotor and the output wheel respectively. The holding parts 36 and 37 arranged over the sleeve 76, which serves as torsion member 38, are fastened to the sleeve, e.g. by adhesive bonding, at locations 84 and 85. The holding parts therefore rotate with the torsion member 38 or the pedal spindle. The holding parts hold magnet poles, which are configured as essentially band-shaped strip poles, as has already been explained for the above torque sensor. In this case, two magnet poles 43 and 53 are shown in the figure. The coil 48 or 58 respectively, which is fastened to the housing in a stationary position and is thus stationary relative to the rotatable holding parts 36 and 37, is arranged inside an annular yoke 47 or 57 respectively composed of two parts. In this case, as in the exemplary embodiments of the torque sensor already shown, a coil carrier, which is provided if need be, is not shown in order to simplify the drawing. The magnet-pole torque sensor works in the way described with reference to the examples according to Figures 4-6. The muscle-power torque induced in the drive on the spindle 1 leads to rotation of the sleeve 76 or the torsion section 39 respectively, thus to a shift of the magnet poles relative to one another and thus to a change in the magnetic flux, which is detected by the coil 58. An electronic analyzing system or a part thereof may be arranged on a plate 89 in a stationary position above the stationary coils. In the torque sensor shown according to Figure 9, an electromagnetic screen in the form of a ring 90, e.g. made of copper, is preferably provided in the radial direction above the magnet poles. A
further electromagnetic screen arranged radially below the magnet poles in the form of a ring 91 which also rotates is also preferably provided. Such an electromagnetic screen, either with one annular screen element or both annular screen elements, may also be provided in the case of a sensor according to Figure 4-8. It has been found that this screen can screen electromagnetic interference on the sensor, a factor which facilitates the analysis of the output signal of the sensor.
Instead of the torque sensor shown on a magnetic basis, a torque sensor, e.g. with strain gages, may also be used, as already explained. In this case, too, the introduction and outputting of the operating voltage or the useful signal to the strain gage arranged on the sleeve or the pedal spindle may be effected in each case by means of a stationary coil 48 and 58, which in this case is opposite a coil which rotates with the strain gage, is likewise provided with a yoke and is fed or scanned via the air gap present between the yokes. In an embodiment variant, the torque detection could also be effected at the abovementioned torque-transmission ring 78, e.g. by strain gages on its webs.
In the already existing g u's~~"~ower-amplifying a in which the auxiliary drive sits in the region of the pedal bearing, the motor is usually arranged outside the pedal bearing, so that the motor spindle is parallel to or at right angles to the pedal spindle. In these known drive concepts, the problem occurs that they consist of many individual parts and therefore require a relatively large amount of space.
This results in losses in the overall efficiency, a large maintenance cost, wear, a high weight, increased susceptibility to dirt, etc.
DE-A-195 22 419 shows a gearless drive unit which is arranged coaxially to the pedal spindle and is designed for retrofitting conventional bicycles and in which a stator of an electric motor and a rotor combined with the sprocket wheel are arranged outside the pedal-bearing cartridge in an exposed position on the bicycle. The electric motor has a low rotational speed within the range of the pedal rotational speed. Rotary-measuring [sic] strips at the connecting point between crank star and sprocket wheel are used as torque sensors. The retrofit solution shown in this document has various disadvantages. The conventional bicycle frame offers little installation space in the pedal-bearing region, so that the motor width is greatly restricted as a result . The torque required for satisfactory and ample motor assistance can only be achieved by a large diameter in this type of construction, a factor which reduces the ground clearance in the pedal-bearing region.
Owing to the fact that the drive is located in the region of spray water, this results in a correspondingly high maintenance cost, increased susceptibility to dirt, and wear.
The installation of an effective seal is very complicated, since the interface of rotor and stator is on a large diameter. The torque applied by the cyclist, which torque may be highly pulsating depending on the crank position, is passed on via the rotor, mounted only on one side, and transmitted to the bicycle chain via a single transmission point. This results in large torsional stresses in the motor region, so that it is difficult to exactly maintain a uniform air gap between rotor and stator.
EP-A-0743 238 shows a drive unit for a bicycle in which a motor having a small diameter and higher rotational speed is used, for which reason transmission gearing is fitted for adapting the very low pedal-spindle rotational speed to the higher rotational speed of the motor. Since the comparatively very high cyclist torque has to be "stepped up"
via this gearing, considerable losses result. Owing to the fact that the rotational speeds of motor and drive gear are relatively high, a freewheel clutch is required for decoupling the motor during travel operation without motor assistance, otherwise a large motor braking torque results during this travel operation. Furthermore, pushing the vehicle backward is made more difficult.
Since a freewheel is fitted in the train of the force-transmission flow from pedal spindle to the output wheel for decoupling the pedals during pure motor travel operation, a back-pedalling brake can no longer be used without additional attachments. The torque is detected by a load cell at the supporting point of the gear housing, which is arranged in the drive housing.
Furthermore, w0 97/05010 shows a wheelchair having wheel-hub motors and muscle-power actuation by a handrail, a sensor being arranged between handrail and the rotor in order to detect the torque induced via the handrail.
In the most diverse applications, such as, for example, motor-driven screwdrivers, drilling machines, motor-operated drives in general and in particular motor-operated actuators or the abovementioned electromotive auxiliary drives of vehicles actuated by muscle power, it is desirable to be able to detect torque. Various mechanical torque sensors are known, which, however, often have a complicated construction and their detection principle makes integration in an fre . d -7 82 romec 'sted 8 890 shows V
_ 4 0._ electronic motor control complicated. EP-A-683 093 and EP-A-700 825 show electromechanical torque sensors in bicycles assisted by electric motor, in which the torque is AMENDED PAGE
detected via the stroke of a lever, extending transversely in the housing, and a stroke sensor. GB-A-2 312 403 shows an electric bicycle drive in which a motor with gearing and freewheel is arranged in a housing coaxially to the pedal spindle. US-A-3 938 890 shows electro-optical torque detection, which in drives which contain lubricants can result in problems with the optical detection. EP-A-682 238 shows a torque-measurement device in which a magnetic field is produced by a coil and is transmitted via two pole-pair arrangements on either side of a torsion section. The magnetic coupling of the poles, which are separated by an air gap, depends on torsion and thus on torque. The magnetic field passes into and out of the poles via an air gap.
Magnetic-field sensors are provided at the return point in order to detect the torque- or torsion-dependent change in the magnetic field. From the signal of the magnetic-field sensors, an output signal corresponding to the torque is produced in an analyzing circuit. The production of the device is expensive, since the poles are designed as pins which have to be arranged individually in apertures of the respective non-magnetic carrier, and this has to be done very precisely in order to keep the air gap between all the opposite pins as uniformly large as possible. In restricted installation conditions and with correspondingly small dimensions, such a device is complicated and expensive to produce. US-A-4 876 899 shows a torque sensor having AMENDED PAGE
continuous pole arrangements on either side of a torsion section, in which pole arrangements introduction is effected via a central coil and the outputting is effected via two lateral coils.
The object of the invention, on the one hand, is therefore to provide a motor-assisted muscle-power drive which has a simple construction, requires little space and is insensitive to dirt and spray water for applications in vehicles and the torque detection of which enables the torque produced by muscle power to be detected as far as possible free from delay and with high resolution. This object is achieved in a drive device of the type mentioned at the beginning having the characterizing features of Claim 1.
Owing to the fact that the torque-detection unit is arranged centrally in the housing and can receive the muscle-power torque directly. [sic] this results in both a compact drive arrangement and the possibility of detecting the torque with good resolution and without interference from gear units or mechanical transmission members. Furthermore, the torque-detection unit is accommodated in the housing in a protected manner.
In a preferred embodiment, the torque-detection unit comprises a sleeve which at least partly accommodates the spindle and may also be part of the rotor or be connected to the latter preferably via a transmission ring, to which the output wheel is also fastened. The torque-detection unit may AMENDED PAGE
be designed with strain gages; however, it preferably has a torque sensor having magnet poles, which are arranged on either side of a torsion section and change their relative position during torsion of the section, which results in a change in a magnetic variable, this change corresponding to the torque. A preferred field of use of the drive is in an electric bicycle.
On the other hand, the object of the invention is to provide a torque sensor which is compact and simple in construction and thus simple and inexpensive to produce and which nonetheless has a high resolution and good measuring accuracy for the torque.
The object is achieved by the characterizing features of Claim 18. The arrangement of an annular coil around the torsion member, while maintaining a simple construction, results in the possibility of a radially or axially low overall height of the sensor, and the magnetic variable is detected by a further coil arranged around the torsion member in an annular manner.
Furthermore, the object of the invention is to provide a method of producing a torque sensor having magnet poles which permits its simple and cost-effective production even in the case of a high number of poles and with very small air-gap tolerances.
This object is achieved by the characterizing features of Claim 24.
AMENDED PAGE
_ g _ Owing to the fact that first of all a ring is formed and connected to the holding parts and that only then are the poles cut out of the ring, cost-effective production results, since the poles do not have to be fastened individually to the holding parts; furthermore, due to the subsequent forming of the poles in the fitted state, the accuracy of the air gaps is determined essentially only by the cutting operation, which is preferably carried out with a laser.
The poles are preferably already preformed at a flat strip before the latter is rounded to form the ring, a factor which reduces the number of subsequent cutting operations.
Brief description of the drawings Exemplary embodiments of the invention are explained in more detail below with reference to the drawings, in which:
AMENDED PAGE
_ g _ achieve es of Claim 24.
Owing to the fact that first of all a ring formed and connected to the holding parts and that o then are the poles cut out of the ring, cost-effective roduction results, since the poles do not have to be f stened individually to the holding parts; furthermore, d to the subsequent forming of the poles in the fitted s te, the accuracy of the air gaps is determined essentia y only by the cutting operation, which is preferably car ed out with a laser.
The poles are referably already preformed at a flat strip before the atter is rounded to form the ring, a factor which reduces he number of subsequent cutting operations.
Brief description of the drawings Exemplary embodiments of the invention are explained in --~~ cn Figure 1 shows a sectional representation of a first embodiment of the drive device;
Figure 2 shows a sectional representation through a further embodiment of the drive device;
Figure 3 shows a side view of a bicycle;
Figure 4 shows a schematic diagrammatic magnetic-field torque sensor;
Figure 5 shows a schematic side view of poles and the magnetic-field introduction of the sensor of Figure 4;
Figure 6 shows a schematic plan view of a partial development of the poles of the sensor of Figure 4;
Figure 7 shows a plan view of a stamping for producing the poles of the sensor;
Figure 8 shows a ring part pushed onto two holders on a torsion section and intended for forming the poles;
Figure 9 shows a sectional representation of a drive device similar to that of Figure 1 having a magnetic-field torque sensor.
Best way of implementing the invention Figure 1 shows a drive device according to the invention in an electric bicycle in section. In this case, the pedal spindle 1 is mounted as a central spindle inside the rotor 6 of the electric motor 10, the rotor consisting of the magnetic return ring 7 having the magnets 8, the disk-shaped rotor body 6a and a sleeve part 6b, which encloses the central spindle 1 and in which the pedal spindle 1 is guided axially and radially by suitable means. However, the mounting of the pedal spindle 1 may also be modified by virtue of the fact that the pedal spindle 1 may be mounted directly in the housing 15 or partly in the housing 15 and partly in the rotor 6. The pedal cranks 4, 5 having the pedals 2, 3 (only partly shown) are fastened to the ends of the pedal spindle 1. In order to transmit the muscle-power torque, the pedal cranks 4, 5 are detachably connected to the pedal spindle 1, but a fixed connection is also conceivable.
The spindle 1 is firmly connected to the sleeve 6b at location 18, e.g. by welding. The spindle 1 is rotatably mounted in the sleeve 6b at location 19 , a . g . by means of a sliding intermediate layer. In this way, the torque of both cranks is passed into the sleeve 6b via the spindle 1 at location 18.
The drive housing 15 is firmly connected to the frame 16; if need be it may be detachably fastened or be designed as an integral frame part.
The sprocket wheel 11, which in this case serves as output wheel, is connected to the rotor 6 so as to be fixed in terms of torque, but is connected to the pedal spindle 1 in a torsionally elastic manner via the sleeve part 6b of the rotor 6. The sprocket wheel 11 sits on the sleeve part 6b of the rotor 6 on the outside of the housing 15 and is in engagement with the rear wheel of the bicycle by means of a force-transmission means 12, e.g. a chain. However, the coupling between sprocket wheel 11 and rotor 6 could also be effected in another way by the sprocket wheel sitting directly on the radially running disk-shaped rotor body 6a or by being designed as an integral part of the rotor body. The rotor 6 is in each case supported via a bearing 13, 13' both on the side of the output wheel 11 and on the other side of the pedal spindle 1. Alternatively, the rotor 6 could be mounted, for example, both in the housing 15 and on the pedal spindle 1. Rolling-contact bearings or sliding bearings are suitable as bearings for both the rotor mounting and the pedal-spindle mounting, and in the simplest case, in which no relative movement takes place between rotor and spindle, the support may be effected as a fixed connection. The bearings of the pedal spindle and of the rotor advantageously lie in one plane; but a position of the bearings relative to one another which differs therefrom is also conceivable. The electric motor 10, consisting of stator 9 and rotor 6, is arranged coaxially to the pedal spindle 1. It may advantageously be designed as a permanently excited synchronous motor, the stator 9 being firmly connected to the drive housing 15 or being provided as a housing part. A very expedient motor configuration is obtained through the use of an external rotor.
The torque-detection unit 14 is arranged centrally in the housing coaxially to the pedal spindle 1 and is assigned directly to the rotor sleeve part 6b. In this case it detects the torsion of the sleeve 6b on the basis of the muscle-power-produced torque induced in this sleeve 6b. The detection is effected, for example, by means of a torque sensor having a strain-measuring element fastened to the sleeve or preferably having a magnetic-pole sensor, as will be explained. The unit 14 is located entirely in the interior of the drive housing 15 and, in the example shown, can detect both torque on the rotor sleeve part 6b and torque on the disk-shaped rotor body 6a by means of the strain gages 31 and 32 shown. Thus, depending on the design of the motor control, both the muscle-power torque and the motor torque can be detected individually or both together by means of the rotor parts 6a, 6b, which are under torsional stress due to the torque and serve as measuring section. The torque originating from the pedal force of the cyclist is detected via the deformation of the rotor sleeve part 6b as a result of torsion and is measured and analyzed by an operatively connected, electronic sensory measuring system. If, for example, torque is transmitted by the pedals 2, 3, the torque signal obtained is processed in real time by a motor control unit 17, which may also be integrated in the drive interior, and controlled in accordance with the electric motor 10 or its torque is adapted to the instantaneous power requirement.
In this way, freewheels or clutches may be completely dispensed with, which leads to a low-wear drive unit and a correspondingly high efficiency.
Figure 2 shows, in section, a modification of the drive device integrated in the pedal-bearing region of an electric bicycle. The pedal spindle 1 is again placed as a central spindle inside the rotor 6 of the electric motor 10 and is mounted partly in the housing 15 and partly in the rotor 6.
However, this may also be achieved as in Figure 1.
The pedal cranks may again be fastened to the ends of the pedal spindle . The drive housing 15 is firmly connected to the frame; if need be it may be detachably fastened or designed as an integral frame part. In this example, the spindle 1 is provided with an annular part lc in the center, and this annular part lc is firmly connected to the sleeve 6b of the rotor 6. Here, too, a sliding intermediate layer 19 is provided between spindle and rotor. In this design, via the two torsion sections la, lb, which each form a part of the pedal spindle 1, two different torques, the torques of both cranks, are separately detected and analyzed. The sprocket wheel 11 (output wheel) again sits on the rotor 6 on the outside of the housing 15 so as to be fixed in terms of torque and is in engagement with the rear wheel of the bicycle by means of a force-transmission means 12, e.g. a chain. However, the coupling between sprocket wheel 11 and rotor 6 could also be effected in another way by the sprocket wheel sitting directly on the radially running disk-shaped rotor body 6a or by being designed as an integral part of the rotor body. The rotor 6 or respectively the pedal spindle 1 is in each case supported via a bearing 13 , 13' both on the side of the output wheel 11 and on the other side of the pedal spindle 1. Alternatively, the rotor 6 could be mounted, for example, on either side in the housing 15. Rolling-contact bearings or sliding bearings are suitable as bearings for both the rotor mounting and the pedal-spindle mounting.
The electric motor 10, consisting of stator 9 and rotor 6, is arranged coaxially to the pedal spindle 1. It is preferably designed as a permanently excited synchronous motor, the stator 9 being firmly connected to the drive housing 15 or being provided as a housing part. A very expedient motor configuration is obtained through the use of an external rotor.
The torque-detection unit is located entirely in the interior of the drive housing, consists of two parts 14a, 14b in this case and is arranged coaxially to the pedal spindle 1. Thus, depending on the design of the motor control, the torques of both cranks may be separately detected and analyzed. The torques originating from the pedal forces of the cyclist are detected via the deformation of the pedal-spindle torsion sections la, 1b, e.g. again via strain gages or magnetic-pole sensors, and are measured and analyzed by an operatively connected, electronic sensory measuring system.
By a motor-control unit 17, which is known per se and is not explained in any more detail here and which may also be integrated in the drive interior, the torque signals obtained are processed in real time and controlled in accordance with the electric motor 10 or its torque is adapted to the instantaneous power requirement. Freewheels or clutches may again be completely dispensed with, which leads to a low-wear drive unit and a correspondingly high efficiency.
Figure 3, as a side view, shows how, for example, a complete concept for a fully sprung electric bicycle 30 having the drive device 1 according to the invention may look. The main frame 25 is connected to the drive link 28 via pivot 24 and spring/damper element 21. Frame struts 4 connect the main frame 25 and seat pillar 26. The drive device 1 sits in the drive link 28. The battery container 18 forms the actual energy box, in which the charging device, the motor-control unit, removed from the drive in this example, and possible displays 23 can be accommodated. The rear wheel hub 22 may be designed with a commercially available hub gear, a derailleur gear or a combination of both.
Figure 4 shows a torque sensor which has two holding members 36 and 37, which are fastened separately from one another on a tors ion member 3 8 , a . g . a shaf t or sleeve . In this case, that region of the torsion member 38 which lies between the holding members 36 and 37 forms a torsion section, the torsion of which is determined by means of the magnet poles arranged on the holding members 36 and 37. Only some of the magnet poles 40-45 of the one holding member or 50-56 of the other holding member are shown in Figure 4, said magnet poles being fastened to the holding parts all around the torsion member. The magnet poles 40 [lacuna] are arranged so as to point toward one another, in which case they are staggered relative to one another in the example of Figure 4.
A magnetic flux is produced in the poles by a coil 48 (only intimated in Figure 4) extending in an annular manner around the holding part 36. In this case, the magnetic flux is fed from the stationary coil 48 into the poles 40 to 45 of the holding part 36 via their respective rear end regions 40' to 45'. In this case, in the example of Figure 4, the magnetic field is fed in via the coil 48 and the torsion-induced change in the magnetic flux through the poles is detected by means of a further coil 58, which is directed in an annular manner around the holding part 37 or around the poles 50-56 with their end regions 51'-55' shown. The magnetic flux is preferably introduced via an air gap in a non-contact manner, so that the torsion member 38 with the holding parts 36, 37 fastened thereto or the poles can rotate relative to the stationary coils. The torque at a rotating shaft or sleeve 38 can therefore be detected, thus, for example, at a shaft of a drive moved by muscle power or by a motor.
Figure 5 and Figure 6 show schematic representations for explaining the mode of operation of the torque sensor of Figure 4. In this case, Figure 5 shows a side view of two respective magnet poles 42, 43 and 52, 53, and Figure 6 shows a plan view of such magnet poles for explaining the magnetic flux. The torsion member 38 is again shown in Figure 5 and forms a torsion section 39 between the holding parts 36 and 37 intimated, for which purpose the torsion member may also have a zone of weakening at this location, as shown by the reduced cross section over the torsion section 39. The torsion member is shown in half vertical section above its center axis D; the other parts of the drawing, however, are only shown schematically for explaining the mode of operation together with the likewise schematic view of Figure 6. Thus the holders 36 and 37 for the magnet poles are only intimated. The coil, likewise only intimated by a pair of winding wires 48, is arranged in a yoke 47, the legs 47' of which point toward the end pieces 43' and 42' respectively of the magnet poles 42 and 43 shown. When current flows from a source 60 indicated, which feeds the coil 48, in the direction of the current-flow symbol 49, a magnetic south pole S and north pole N respectively are obtained at the yoke legs 47'. The magnetic flux produced as a result in the magnet poles 42 and 43 is shown by the broken lines F in Figure 6. In the idle state of the torque sensor, i.e.
without torsion of the torsion section 39, the magnet poles 42, 43 and 53 and 54 are located opposite one another as shown in Figure 6. In this figure, the position of the yoke legs 47' is indicated by broken lines. The annular coil 48 surrounding the holding part, with its annular yoke 47, which likewise extends around the holding part 36, produces a magnetic flux F, which essentially passes at the front end of the magnet pole 42 through the air gap d into the magnet pole 53 and from the latter again into the magnet pole 43 and back to the yoke 47. A small portion of the flux may also flow in this position via the magnet pole 53 or its end 53' and via the yoke 57 of the coil 58 into the end 54' of the magnet pole 54 and through the latter back to the magnet pole 43 and the yoke 47. This small magnetic flux produces an electric voltage in the coil 58, which in Figure 5 is also only intimated by a pair of winding wires, and this electric voltage may be amplified in an amplifier 61 and rectified in a rectifier 62. In this case, the voltage induced in the coil 58 in the idle state corresponds to the lower value of the detectable torque, since torsion of the torsion section 39 still does not occur in this idle state. If a torque which leads to torsion of the torsion section 39 is now transmitted via the torsion member 38, the holding member 36, for example, rotates relative to the holding member 37 in such a way that a movement of the magnet poles 42, 43 in the direction of arrow B in Figure 6 is obtained. The magnet poles 42 and 53 and respectively 43 and 54 are displaced relative to one another in such a way that their end faces have a slight overlap over the air gap d, a factor which leads to the magnetic flux passing increasingly via the magnet poles 53 and 54 and via the yoke 57, so that the voltage induced in the coil 58 increases . In this case, the increasing voltage in the coil 58 or after amplification and rectification at the output of the rectifier 62 is approximately proportional within the measuring range to the rotation of the torsion section 39 or to the torque induced in the torque sensor. Thus, for example, with a torque sensor of a few centimeters diameter, a torque of 1 Nm up to 300 Nm can be measured in this way with good resolution at an appropriately designed torsion section. In this case, the value of 300 Nm may produce a rotation of about 1.5° of the torsion section. If the coil 47 is fed with a voltage signal of 3.5 V and a frequency of 14 kHz, a useful signal in the coil 58 of 5 mV, which may be amplified and rectified, is obtained. The DC voltage delivered at the rectifier 62 may be delivered as a measured value for the torque to a display device or an open-loop or closed-loop control, which controls a drive for example. In a preferred type of use, the muscle-power torque at a pedal spindle or a sleeve connected to the latter is detected in said manner and used for the open-loop or closed-loop control of an electric auxiliary drive. The essentially band-shaped configuration of the magnet poles which is shown in Figure 4 permits a small overall height of the torque sensor, which is advantageous for its use in a wide variety of drives or for a wide variety of torque-measuring tasks. The feeding or the measuring of the magnetic flux by means of ring coils, as likewise shown in Figures 4-6, likewise permits the design of the torque sensor with a small diameter or a small overall height.
In this case, the embodiment shown, having a number of magnet poles completely staggered relative to one another, is only to be understood as a preferred example. The magnet poles, pointing toward one another, of the two holding parts 36 and 37 could also be staggered relative to one another to a smaller degree in the idle state or could also be exactly opposite one another. The latter case results in the maximum magnetic coupling from the coil 48 to the coil 58 when the torsion section is not rotated. Rotation of the torsion section then results in less coupling to the coil 58 and thus a signal decreasing in accordance with the torque. More than one row of magnet poles, as disclosed by EP-A-0682 238, could also be used.
The sensor described is produced according to the invention by a closed ring first of all being formed from the ferromagnetic material forming the magnet poles, this ferromagnetic material preferably being in the form of a band. This ring is now pushed onto the two ends of the non-magnetic holding parts 36, 37 and fastened there at those points where the poles are to be fastened to the holding parts. This may be effected, for example, by spot-like adhesive bonding of the ring to the holding parts 36 and 37.
The latter are fastened to the torsion member 38 at the same time or subsequently, e.g. likewise by adhesive bonding or pinning. The magnet poles are then cut out of the closed ring by a laser beam, in which case the parts of the ring which are fastened to the holding parts 36 and 37 form the magnet poles and the unfastened parts are removed as cut waste. In this case, a circumferential cut in the center of the ring separates the poles of the two holding parts from one another. The non-fastened parts of the ring which lie between the poles of each holding part are released from the poles by cuts along the lateral lines of the cylindrical ring. After the poles have been formed, they may be fastened to the holding parts in a more intensive manner by a casting compound for example. The production method described has the advantage that the magnet poles do not have to be separately formed beforehand and fastened individually to the holding parts, and that, by the fastened ring being cut with the holding parts already positioned relative to one another on the torsion member, an air gap which is uniform to an extremely accurate degree over the circumference of the torque sensor is produced, which permits corresponding accuracy and fine resolution of the torque measurement.
A modified, preferred production method is explained with reference to Figures 7 and 8. In this case, Figure 7 shows a pole strip 65 of ferromagnetic material, which has a continuous web 66 and legs 67 projecting from the web 66 in a staggered manner. The legs may also have a different length from one another. Such a strip may be produced, for example, by a stamping or cutting operation. The successive legs 67 of each side of the pole strip are then alternately bent approximately in such a way as shown schematically in Figure for the successive pole strips 42 and 43 or 52 and 53 respectively. The pole strip bent in this way is then bent into a ring, as partly shown as ring 69 in Figure 8. In this case, the actual ring is formed by the web 66, and the bent legs 67 proj ect from this ring on both sides . The pole ring 69 in this case is now pushed with its legs 67 onto the non-magnetic holding parts 36 and 37 respectively, in which case the latter, as shown in Figure 8, may be of stepped design and may be provided with slots 70 and 71, in which the legs are accommodated. In this case, Figure 8 shows the ring 69 already pushed onto the holding part 36 and shows the holding part 37 in a position that (sic] it can likewise be joined together with the ring 39. In addition, the torsion member 38 with the torsion section 39 is inserted into the holding parts 36 and 37. In this case, the bent legs 67, with their end regions projecting upward, form the end regions of the magnet poles still to be formed, as indicated for one leg by the reference numeral 43' in accordance with that of Figure 5. The legs 67 may be adhesively bonded in the slots 70 and 71 of the respective holding parts. Furthermore, the stepped part of the holding parts may be covered by a hardening casting compound after the holding parts have been pushed together, so that, of the magnet poles, only the angled end regions project radially from the holding parts 36 and 37 and the web 66 is exposed between the holding parts. After the casting compound has hardened, the circumference of the holding parts 36 and 37 may be turned or ground, so that the end regions of the magnet poles, e.g. the end region 43' , is flush with the outer surface of the holding part. After the holding parts 36 and 37 have been fixed in place on the torsion member 38 as described and the magnet-pole legs 67 have been fastened to and in the holding parts, the web 66, as already mentioned, is now cut in such a way that the individual magnet poles are formed. Thus the air gap d is formed between the opposite magnet poles by a circumferential cutting line L, e.g. by means of a laser. This air gap, for example, may have a size of 0.3 mm, which remains constant even after the cutting due to the already fixed bearings [sic] of all parts relative to one another. Furthermore, the hatched parts can be cut out by cuts through the web 66 in the axial direction, so that the magnet-pole arrangement according to Figure 4 having magnet poles opposite one another in a staggered manner is obtained. Of course, magnet poles which are not staggered relative to one another could also be obtained by appropriate shaping of the strip 65.
Figure 9 shows a drive device of a bicycle having an electromotive auxiliary drive similar to that of Figure 1, using a torque sensor as has been described with reference to Figures 4-8. In this case, the same reference numerals as used previously describe the same parts. Since the drive device is symmetrical to the longitudinal axis, essentially only the part lying above the longitudinal axis is shown and this part is also truncated toward the top in the figure, so that only part of the rotor and the housing of the output wheel can be seen. In the example shown, the pedal spindle 1 is welded to the sleeve 76 at location 75. That region of the pedal spindle which lies inside the sleeve is movably mounted relative to the sleeve by a sliding intermediate layer 19. In this way, the torque induced in the pedal spindle 1 by the pedal cranks (not shown) is transmitted to the sleeve at location 75. The sleeve at the same time forms the torsion member 38 of a torque sensor having magnet poles. For this purpose, the sleeve is designed to be thinner in the region of the torsion section 39 in order to permit torsion there on account of the muscle power induced. At its other end, the sleeve 76 is firmly connected, e.g. welded, at location 77 to a torsion-transmission ring 78. This ring is also mounted so as to slide relative to the pedal spindle. Engaging on the torsion-transmission ring 78 in a torsionally rigid manner is, on the one hand, the rotor 6, and, on the other hand, the output wheel 11 on the outside of the housing, which is a sprocket wheel for example. In this case, the ring 78 is provided with apertures 80, which are separated from one another by ribs and in which pins 81 and 82 of the rotor and the output wheel respectively engage in order to ensure the torque transmission from the torsion-transmission ring 78 to the rotor and the output wheel respectively. The holding parts 36 and 37 arranged over the sleeve 76, which serves as torsion member 38, are fastened to the sleeve, e.g. by adhesive bonding, at locations 84 and 85. The holding parts therefore rotate with the torsion member 38 or the pedal spindle. The holding parts hold magnet poles, which are configured as essentially band-shaped strip poles, as has already been explained for the above torque sensor. In this case, two magnet poles 43 and 53 are shown in the figure. The coil 48 or 58 respectively, which is fastened to the housing in a stationary position and is thus stationary relative to the rotatable holding parts 36 and 37, is arranged inside an annular yoke 47 or 57 respectively composed of two parts. In this case, as in the exemplary embodiments of the torque sensor already shown, a coil carrier, which is provided if need be, is not shown in order to simplify the drawing. The magnet-pole torque sensor works in the way described with reference to the examples according to Figures 4-6. The muscle-power torque induced in the drive on the spindle 1 leads to rotation of the sleeve 76 or the torsion section 39 respectively, thus to a shift of the magnet poles relative to one another and thus to a change in the magnetic flux, which is detected by the coil 58. An electronic analyzing system or a part thereof may be arranged on a plate 89 in a stationary position above the stationary coils. In the torque sensor shown according to Figure 9, an electromagnetic screen in the form of a ring 90, e.g. made of copper, is preferably provided in the radial direction above the magnet poles. A
further electromagnetic screen arranged radially below the magnet poles in the form of a ring 91 which also rotates is also preferably provided. Such an electromagnetic screen, either with one annular screen element or both annular screen elements, may also be provided in the case of a sensor according to Figure 4-8. It has been found that this screen can screen electromagnetic interference on the sensor, a factor which facilitates the analysis of the output signal of the sensor.
Instead of the torque sensor shown on a magnetic basis, a torque sensor, e.g. with strain gages, may also be used, as already explained. In this case, too, the introduction and outputting of the operating voltage or the useful signal to the strain gage arranged on the sleeve or the pedal spindle may be effected in each case by means of a stationary coil 48 and 58, which in this case is opposite a coil which rotates with the strain gage, is likewise provided with a yoke and is fed or scanned via the air gap present between the yokes. In an embodiment variant, the torque detection could also be effected at the abovementioned torque-transmission ring 78, e.g. by strain gages on its webs.
Claims (30)
1. Drive device having electromotive auxiliary-force assistance of an input torque originating from muscle-power work, having at least one output wheel (11) and having a spindle (1) for receiving the muscle-power torque, which spindle is arranged in a housing (15) and is supported in at least one bearing (13, 13'), an electric motor (10) which consists of a stator (9) and a rotor (6) being accommodated in the housing, to which electric motor (10) a motor-control unit (17) for the open-loop control and/or closed-loop control of the motor torque is assigned, and furthermore the spindle having means for receiving the at least one muscle-power input torque, characterized in that the muscle-power torque and/or the torque of the electric motor (10) can be detected by means of a torque-detection unit (14, 14a, 14b) having a torque sensor, and in that the torque-detection unit is arranged centrally in the housing in the region of the spindle in such a way that the muscle-power torque can be induced directly in the torque sensor of the torque-detection unit.
2. Drive device according to Claim 1, characterized in that the rotor for the torque superimposition is connected to the spindle, and the torque-detection unit engages between spindle and rotor or between the latter and the output wheel in such a way as to measure torque by virtue of the fact that -27a-it is at least partly integrated in the connection between rotor and spindle or rotor and output wheel, and in that the output wheel for transmitting the output torque is connected to the rotor or is designed as part of the rotor.
3. Drive device according to Claim 1 or 2, characterized in that the torque-detection unit responds to the torsion of the spindle (1).
4. Drive device according to Claim 1 or 2, characterized in that the torque-detection
5. Drive device according to Claim 4, characterized in that the sleeve (6b) is formed by a part of the rotor.
6. Drive device according to Claim 4, characterized in that the sleeve has a torsion-transmission ring (1c; 78) on which the rotor is arranged on the inside of the housing and the output wheel is arranged on the inside [sic] of the housing.
7. Drive device according to one of Claims 1 to 6, characterized in that the torque-detection unit responds to the deformation of a rotor part (6a) which projects from the spindle.
8. Drive device according to one of Claims 1 to 7, characterized in that the torque-detection unit has at least one strain gage and inductive transmission means for its electrical feed and output-signal detection.
9. Drive device according to one of Claims 1 to 7, characterized in that the torque-detection unit (35) has at least one magnet-pole arrangement (40-45, 50-56) having a magnetic flux variable by torsion, which magnet-pole arrangement can be fed by a magnetic field and its magnetic flux can be detected by at least one magnetic-field sensor, preferably a coil arrangement (58).
10. Drive device according to Claim 9, characterized in that an electromagnetic screen (90, 91), preferably in the form of a ring, e.g. made of copper, is arranged above and/or below the magnet-pole arrangement.
11. Drive device according to one of Claims 1 to 10, characterized in that the stator of the motor is fixed, is in particular detachably connected to the housing (10) [sic] or is designed as a housing part, and the housing is designed in a closed form and in particular is sealed off from the spindle by means of seals.
12. Drive device according to one of Claims 1 to 11, characterized in that the spindle is mounted in the rotor and/or housing.
13. Drive device according to one of Claims 1 to 12, characterized in that the spindle and rotor each have the same rotational speed.
14. Drive device according to one of Claims 1 to 13, characterized in that the motor-control unit superimposes the motor torque without a time delay or in a delayed manner as a linear or non-linear function of the muscle-power torque and/or of the spindle rotational speed, the motor-control unit if need be being accommodated in the housing and being advantageously designed in such a way that the motor feeds a variable torque, preferably in a program-controlled manner, in particular for each revolution of the input-torque spindle.
15. Drive device according to one of Claims 1 to 14, characterized in that the motor has a large number of poles and/or is brushless, and the rotor is preferably designed as an external rotor.
16. Drive device according to one of Claims 1 to 15, characterized in that the motor is a permanently excited synchronous motor, preferably a commutatorless direct-current motor.
17. Bicycle having a drive device according to one of Claims 1 to 16.
18. Torque sensor (35) comprising a magnet arrangement (47, 48) and individual magnet poles (40-45, 50-56), which are fed by the magnet arrangement (47, 48), are arranged in an annular manner and are arranged on both sides of a torsion section (39), rotatable by the torque, of a torsion member (38) in such a way as to point toward one another, and having a detection arrangement (57, 58) for detecting a change in at least one magnetic variable, the change being caused by the torsion-induced relative movement of the magnet poles relative to one another, characterized in that the magnetic variable [sic], characterized in that the magnet arrangement has a coil (48) arranged in an annular manner around the torsion member at one end of the torsion section and having a yoke (47) with radially running legs (47'), and in that the detection arrangement comprises a coil (58) arranged in an annular manner around the torsion member at the other end of the torsion section and having a yoke (57) with radial legs (57').
19. Torque sensor according to Claim 18, characterized in that the poles are designed essentially as band-shaped strips.
20. Torque sensor according to Claim 18 or 19, characterized in that the poles have angled end regions (40'-45', 51'-56') aligned with the yoke legs.
21. Torque sensor according to one of Claims 18 to 20, characterized in that the poles in the torsionless idle state are opposite one another in such a way as to be staggered relative to one another, in particular staggered by one pole width, or in that the poles are opposite one another without a stagger.
22. Torque sensor according to one of Claims 18 to 21, characterized in that the poles are arranged on non-magnetic carriers (36, 37), and in that an electromagnetic screen is arranged in each case above and/or below the poles.
23. Use of a torque sensor according to one of Claims 18 to 22 in a drive device having electromotive amplification of an input torque originating from muscle power, in particular in a drive device according to one of Claims 1 to 16.
24. Method of producing a torque sensor (35) having individual magnet poles arranged on separate, non-magnetic holding parts (36, 37) on either side of a torsion section (39) of a torsion member (38), characterized in that a ring is formed from the magnet-pole material, in that the ring is fastened to the holding parts and the latter are fastened to the torsion member, and in that the magnet poles are cut out of the ring.
25. Method according to Claim 24, characterized by the following steps:
- forming, in particular by punching, a flat pole strip (65) with legs (67) projecting on either side from a central, elongated web (66);
- forming the ring from the pole strip;
- fastening the ring by means of its legs to the two pole holders and fastening the pole holders to the torsion member;
and - cutting out the poles and the air gap (d) between the poles and the annular web.
- forming, in particular by punching, a flat pole strip (65) with legs (67) projecting on either side from a central, elongated web (66);
- forming the ring from the pole strip;
- fastening the ring by means of its legs to the two pole holders and fastening the pole holders to the torsion member;
and - cutting out the poles and the air gap (d) between the poles and the annular web.
26. Method according to Claim 25, characterized in that the legs are bent relative to the web plane before forming the ring.
27. Method according to Claim 26, characterized in that the legs lying one on top of the other (sic] are bent at different distances from the web.
28. Method according to one of Claims 24 to 27, characterized in that the legs are fastened to the pole holders by a casting compound, preferably after insertion of the legs into slots provided at the pole holders.
29. Method according to one of Claims 24 to 28, characterized in that the cutting-out is effected by means of laser beam.
30. Method according to one of Claims 24 to 29, characterized in that means for producing a magnetic field and detection means for detecting a magnetic variable are assigned to the magnet poles.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH2860/97 | 1997-12-12 | ||
| CH286097 | 1997-12-12 | ||
| PCT/IB1998/001991 WO1999030960A2 (en) | 1997-12-12 | 1998-12-11 | Drive mechanism and torque sensor, and method for the production thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2313484A1 true CA2313484A1 (en) | 1999-06-24 |
Family
ID=4243214
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002313484A Abandoned CA2313484A1 (en) | 1997-12-12 | 1998-12-11 | Drive mechanism and torque sensor, and method for the production thereof |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP1037794A2 (en) |
| JP (1) | JP2002508281A (en) |
| AU (1) | AU1347299A (en) |
| CA (1) | CA2313484A1 (en) |
| WO (1) | WO1999030960A2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103587640A (en) * | 2012-08-17 | 2014-02-19 | 株式会社岛野 | Bicycle drive unit |
Families Citing this family (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6802385B2 (en) | 2002-05-16 | 2004-10-12 | Wavecrest Laboratories, Llc | Electrically powered vehicles having motor and power supply contained within wheels |
| JP4713335B2 (en) * | 2005-12-28 | 2011-06-29 | 株式会社日立産機システム | Motor and electric power steering device |
| WO2009127263A1 (en) * | 2008-04-18 | 2009-10-22 | Philippe Kohlbrenner | Drive for a wheeled vehicle |
| JP5164728B2 (en) * | 2008-08-07 | 2013-03-21 | ヤマハモーターエレクトロニクス株式会社 | Torque sensor |
| EP2216242B1 (en) | 2009-02-04 | 2012-04-04 | Electragil GmbH | Drive device |
| DE102009014246A1 (en) | 2009-03-20 | 2010-09-23 | Schaeffler Technologies Gmbh & Co. Kg | Drive system for a motor-assisted bicycle |
| DE102009014247A1 (en) | 2009-03-20 | 2010-09-23 | Schaeffler Technologies Gmbh & Co. Kg | Drive system for a motor-assisted bicycle |
| DE102009038912A1 (en) | 2009-08-26 | 2011-03-03 | Schaeffler Technologies Gmbh & Co. Kg | Drive system for a motor-assisted bicycle and housing for the drive system |
| DE102009045813A1 (en) | 2009-10-19 | 2011-04-21 | Philippe Kohlbrenner | Drive i.e. hybrid drive, for bicycle, motor pinion engaged with drawing unit or additional drawing unit for transmission of torque of electric motor that is designed as external rotor motor, where motor is provided with stator and rotor |
| DE202009014577U1 (en) * | 2009-10-28 | 2011-03-10 | Daum Gmbh & Co. Kg | Resignation brake |
| CN103442978B (en) * | 2011-03-22 | 2015-11-25 | 李森墉 | Electrical Bicycle and driver train thereof |
| DE102011077903A1 (en) * | 2011-06-21 | 2012-12-27 | Brose Fahrzeugteile Gmbh & Co. Kg, Coburg | Drive device for an electric bike |
| DE102011087544A1 (en) * | 2011-12-01 | 2013-06-06 | Continental Automotive Gmbh | Electric auxiliary drive for a bicycle |
| DE102011120675B4 (en) | 2011-12-02 | 2023-09-28 | Pinion Gmbh | Gear unit |
| DE102017213221A1 (en) | 2017-08-01 | 2019-02-07 | Zf Friedrichshafen Ag | Determination of the twisting component of the torques acting on a shaft |
| DE102018101911A1 (en) | 2018-01-29 | 2019-08-01 | Pinion Gmbh | Torque detection assembly and gear unit for a muscle powered vehicle |
| DE102019203322A1 (en) * | 2019-03-12 | 2020-09-17 | Robert Bosch Gmbh | Torque sensor and drive unit for a bicycle |
| DE102019115401B3 (en) | 2019-06-06 | 2020-06-25 | Innotorq Gmbh | Wheel hub, auxiliary powered vehicle with the wheel hub and bracket assembly |
| FR3112524B1 (en) * | 2020-07-20 | 2024-02-23 | Moving Magnet Tech | CYCLE DRIVE COMPONENT HAVING A TORQUE SENSOR |
Family Cites Families (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB626808A (en) * | 1942-08-18 | 1949-07-21 | Westinghouse Electric Int Co | Improvements in or relating to power indicating or measuring devices |
| US2482477A (en) * | 1944-08-10 | 1949-09-20 | Westinghouse Electric Corp | Electrical torque measuring device |
| FR2264676A1 (en) * | 1974-03-18 | 1975-10-17 | Minier Gerard | Motor driven bicycle wheel - has electric motor in wheel with battery powered epicyclic gearing |
| US3938890A (en) | 1974-10-15 | 1976-02-17 | Flavell Evan R | Torque transducer utilizing differential optical sensing |
| JPS5946526A (en) * | 1982-09-09 | 1984-03-15 | Nissan Motor Co Ltd | Electromagnetic stress sensor |
| US4876899A (en) * | 1988-10-31 | 1989-10-31 | Texas Instruments Incorporated | Torque sensing device |
| JPH03205525A (en) * | 1989-11-17 | 1991-09-09 | Toshiba Corp | Magnetic anisotropy imparting method for band-shaped magnetic body and torque sensor |
| FR2716002B1 (en) | 1994-02-08 | 1996-04-19 | Omahony Gerard | Magnetic torque meter for absolute torque and torque measurements. |
| JP2967391B2 (en) | 1994-05-18 | 1999-10-25 | 本田技研工業株式会社 | Treading force detection device for bicycle with assist motor |
| JP2906023B2 (en) | 1994-09-07 | 1999-06-14 | 本田技研工業株式会社 | Treading force detection device for bicycle with assist motor |
| US5581136A (en) * | 1994-12-20 | 1996-12-03 | Li; I-Ho | Auxiliary magnetic motor (AMM) |
| JP3547847B2 (en) | 1995-05-17 | 2004-07-28 | 本田技研工業株式会社 | Treading force detection device for bicycle with assist motor |
| DE19522419A1 (en) | 1995-06-21 | 1997-01-02 | Dietrich Gerhard Ellsaeser | Bicycle with auxiliary electric drive |
| DE19527680A1 (en) | 1995-07-28 | 1997-03-06 | Efa Gmbh Entwicklungsgesellsch | Muscle-powered wheeled vehicle with an electric auxiliary drive |
| JP3327079B2 (en) * | 1995-11-29 | 2002-09-24 | 松下電器産業株式会社 | Electric bicycle |
| GB2312403B (en) * | 1996-04-26 | 1998-03-25 | Giant Mfg Co | Bicycle equipped with electrical driving device |
-
1998
- 1998-12-11 AU AU13472/99A patent/AU1347299A/en not_active Abandoned
- 1998-12-11 EP EP98957053A patent/EP1037794A2/en not_active Withdrawn
- 1998-12-11 WO PCT/IB1998/001991 patent/WO1999030960A2/en not_active Application Discontinuation
- 1998-12-11 JP JP2000538912A patent/JP2002508281A/en active Pending
- 1998-12-11 CA CA002313484A patent/CA2313484A1/en not_active Abandoned
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103587640A (en) * | 2012-08-17 | 2014-02-19 | 株式会社岛野 | Bicycle drive unit |
| CN103587640B (en) * | 2012-08-17 | 2016-03-02 | 株式会社岛野 | The driver element of bicycle |
Also Published As
| Publication number | Publication date |
|---|---|
| WO1999030960A2 (en) | 1999-06-24 |
| AU1347299A (en) | 1999-07-05 |
| WO1999030960A3 (en) | 1999-08-19 |
| JP2002508281A (en) | 2002-03-19 |
| EP1037794A2 (en) | 2000-09-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2313484A1 (en) | Drive mechanism and torque sensor, and method for the production thereof | |
| JP4091609B2 (en) | Electric bicycle drive device | |
| JP4612061B2 (en) | Electric bicycle drive device | |
| US9027691B2 (en) | Driving unit and electric assist bicycle | |
| JP3670430B2 (en) | Electric bicycle drive device | |
| EP1236640B1 (en) | Control unit for motor-assisted bicycle | |
| CN102381430B (en) | Bicycle with auxiliary power unit | |
| EP2998211B1 (en) | Electrically assisted bicycle | |
| JP5508683B2 (en) | Electric bicycle drive device | |
| JP3660460B2 (en) | Electric bicycle drive device | |
| EP3199439B1 (en) | Middle-mounted motor of an electric bicycle and moment sensing device thereof | |
| EP0776818A1 (en) | Electrically assisted bicycle | |
| US20100305879A1 (en) | Drive device comprising a drive shaft and a device for detecting torque | |
| CN209852516U (en) | Electric power-assisted bicycle and middle motor driving system thereof | |
| CN104276251A (en) | Torque sensing system for middle shaft of electric vehicle | |
| AU2008277325A1 (en) | External-rotor electric motor with or without a planetary gear mechanism, motor vehicle with an external-rotor electric motor and a method for operating such a vehicle | |
| CN102205866B (en) | Motor-fixing structure for assist unit | |
| TW201418101A (en) | Bicycle drive unit | |
| US11945547B2 (en) | Transmission systems for vehicles | |
| CN102205868A (en) | Motor shaft supporting structure in assist unit | |
| CN106143777A (en) | A kind of Moped Scooter built-in motor and moment measuring device thereof | |
| CN110662657B (en) | Hub transmission unit for a vehicle hub, hub and auxiliary drive vehicle | |
| JP3428497B2 (en) | Bicycle with auxiliary power | |
| JP5463071B2 (en) | Electric vehicle equipped with pedal force detection device | |
| JP4873861B2 (en) | Magnetization method of electric assist type bicycle and position detection magnet |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |