WO2012017096A1

WO2012017096A1 - Electrical machine on a disc brake holder

Info

Publication number: WO2012017096A1
Application number: PCT/EP2011/063577
Authority: WO
Inventors: Andreas Felsl; Florian Loeffl; Markus Lindstedt
Original assignee: Momo Plus Ag
Priority date: 2010-08-06
Filing date: 2011-08-05
Publication date: 2012-02-09
Also published as: EP2601092A1

Abstract

The invention discloses an electrical machine for a muscle-powered vehicle, preferably a bicycle, in which a large number of permanent magnets rotate together with a wheel hub and a coil is arranged so as to be fixed to the frame or fork.

Description

description

ELECTRIC MACHINE AT A DISK BRAKE RECEPTION

The invention relates to an electric machine for a preferably muscle-operated vehicle, for example a bicycle according to the preamble of patent claim 1.

Such an electric machine is disclosed in the document DE 600 15 104 T2.

The term "electrical machine" is understood to mean a generator / dynamo, by means of which the kinetic energy of the vehicle is converted into electrical energy In the solutions described in DE 600 15 104 T2, the electric machine is used to supply power to a lighting system to install a coil of electrical machine to a part of the vehicle and

to store at least one permanent magnet on another vehicle part, these two vehicle parts are movable relative to each other. As appropriate

Mounting positions while the spokes of a wheel on the one hand and the fork, or the frame on the other hand or a pedal crank of a bicycle on the one hand and in turn proposed the frame of the bicycle on the other.

Due to the resulting relative movement between coil and

Permanent magnets is induced in the coil, a voltage over which the power supply of a consumer, in the present case, the lighting system takes place.

In principle, by the induced voltage and an energy storage, such as a battery can be charged.

The disclosure of DE 600 15 104 T2 is rather theoretical in nature, with the proposed mounting positions can not operate an electric machine with sufficient efficiency. In contrast, the invention has for its object to provide an electrical machine of a preferably muscle-powered vehicle with improved efficiency.

This task is accomplished by an electric machine with the characteristics of

Patent claim 1 solved.

Advantageous developments of the invention are the subject of the dependent claims.

The electric machine is, as I said, preferably for a human-powered vehicle, such as a bicycle provided to supply its electrical loads with electricity or to charge a battery. The electric machine has a coil and a permanent magnet which are movable relative to each other for inducing a voltage in the coil. According to the invention, the permanent magnets are attached to a wheel hub of the vehicle, while the coil is fixed to the frame, d. H. is arranged on the vehicle frame or on a vehicle fork. The rotation of the

Permanent magnet with the hub is then exploited to induce a voltage in the coil fixed against it, so that a very compact solution is provided. Since the permanent magnets are arranged relatively close to the axis of rotation of the wheel, the moment of inertia of this wheel by the

Permanent magnets not affected, so that the ride comfort or driving performance is not reduced.

In a variant of the invention, a plurality of permanent magnets are arranged on a disk-shaped rotor, which is non-rotatably connected to the wheel hub. The coils are then stationary, preferably attached to a standard disc brake recording. This standard disc brake mount can be designed, for example, according to the IS2000 or PM standards.

In a variant which operates with a particularly high degree of efficiency, two coils or two coil arrangements are accommodated on both sides of the rotor. An embodiment provides to attach the at least one coil via an articulated arm to the standard brake mount.

The articulated arm carries the coils or the coil assembly and is made of a

Induction position in a current release position pivoted, in which the coil or the coil assembly is moved away from the permanent magnet.

The pivoting of the articulated arm may be limited by stops.

Preferably, the rotor is attached to a brake disc receptacle of the wheel hub or coupled thereto. In this way, a device-technical effort for a rotationally fixed connection with the hub is low, since an already existing device is used.

When using multiple coils is a high quality of the generated

Voltage can be achieved if the coils are sequentially arranged one after the other in a direction of rotation of the permanent magnets.

The rotor is inexpensive to manufacture and has a low weight, if it consists mainly or completely of plastic. The plastic is preferably high temperature resistant, for example up to 400 ° C. This property is advantageous when using a disc brake system, when the rotor is close to the

Brake disc is arranged, which can have a temperature up to 800 ° C.

On device-technically simple way, the permanent magnets are arranged or attached via a cohesive connection to the rotor. In this case, the permanent magnets can be fastened in particular via an adhesive bond on the rotor. They can be used in a plastic matrix or surrounded by plastic. It is possible that the permanent magnets are partially or completely covered by plastic. Alternatively or additionally, the

Permanent magnets by positive engagement or adhesion, for example, be attached by a clip connection to the rotor. If a brake disc is attached to the rotor, this results in a

Device technical advantage, since two components, the rotor and the brake disc, are connected via a common part with the wheel hub. The rotor then fulfills the one hand, the function of the permanent magnet carrier and on the other hand, the function of the brake disc carrier. The brake disk is preferably in particular via a

Screwed or fastened via a rivet on the rotor. Although it is also conceivable that the rotor additionally fulfills the function of the brake disc, or vice versa, but is a thermal decoupling of the brake disc from the carrier of

Permanent magnet (rotor) advantageous, which in the bipartite of rotor and

Brake disk is better to implement.

A particularly advantageous design of the at least one coil is given if it extends on both sides of the rotor or on both sides of the permanent magnet, so that the coil covers the rotating rotor or the revolving permanent magnets at least in sections on both sides. This design allows a high power density of the electrical machine.

In order to be able to exploit even a narrow, narrow or flat space, which is the permanent magnet available, these are preferably formed flat transverse to its direction of rotation.

If a space radially outside the rotor for an arrangement of

Permanent magnet is not sufficient or unusable for other reasons, the permanent magnets are preferably arranged substantially laterally on the rotor, in particular on a side surface of the rotor. They are then preferably designed disk-shaped or flat construction, so that even a narrow space can be exploited efficiently laterally of the rotor. In order to achieve a high quality of the generated voltage, the permanent magnets preferably abut each other flush. Particularly preferred are the

Permanent magnets tapered in the radial direction from the outside to the inside. The assembly with permanent magnets can be made very dense in this way.

A particularly compact, shock-resistant and temperature-resistant design of the permanent magnet is obtained if this transversely to its direction of rotation, at least sections have an oval-shaped, circular or polyhedral cross-section. Most preferably, the permanent magnets are cylindrical or approximately curved parallel to the orbit of the permanent magnet curved cylindrical. From these compact designs advantageously results in a high quality of a magnetic flux.

In a preferred variant, the permanent magnets are arranged substantially on an outer circumference of the rotor. Particularly preferred they are compact as described above.

Three preferred embodiments of the invention are explained in more detail below with reference to four partially schematic drawings. Show it:

Figure 1 is a highly schematic partial view of a first embodiment of an electric machine of a bicycle;

FIG. 2 shows the electric machine according to FIG. 1 in a current-free position;

Figure 3 is a partial perspective view of a second embodiment of an electric machine of a bicycle; and

Figure 4 is a partial side view of a third embodiment of a rotor of an electric machine of a bicycle.

The electric machines 1 described below; 101, as well as the rotor 204 of the electrical machine according to FIG. 3, are intended to be used on a vehicle operated by a human powered electric motor and serve to supply electric consumers of this vehicle, for example a bicycle, with electricity or to charge a battery. The electric machine 1 or 101 or the rotor 204 is arranged in the region of a front or rear hub, which is designed with a standard disc brake receptacle 2 and 102, respectively. FIG. 1 shows this area of a first exemplary embodiment in a highly schematic representation. At the front hub, a disc-shaped rotor 4 is fixed, which thus rotates with the hub body. This rotor 4 is designed similar to a brake disc and is provided with recesses 8 to minimize weight. At the peripheral portion of the rotor 4 are a plurality of on a common

Partial circular permanent magnets 10, 12, arranged, which thus rotate with the rotor 4 on a circular path. At the dropout or on a front fork 3 of the bicycle a standard disc brake mount 2 is fixed, which is designed for example according to the standards IS2000 or PM. Instead of a brake caliper this standard disc brake mount 2 carries a pivotable articulated arm 13. At the free end portion of the articulated arm 13, a coil 14 or a coil assembly is arranged. In principle, the articulated arm 13 can also be fork-shaped, so that two coils are aligned on both sides of the rotor 4 with respect to the permanent magnets 10, 12. The

Coil 14 or the coil assembly is connected to a control unit, via which the power supply of the electrical consumers or the charging of the battery is controlled. When the bicycle is rolling, the rotor 4 rotates according to the speed of the wheels, so that via the permanent magnets 10, 12 on the coil 14 and the

Coil arrangement, a voltage is induced. Due to the preferably two-sided arrangement of the coils 14 and the optimized with respect to the permanent magnet bearing rotor 4 is a very easy to install and constructed unit for an electric machine 1 provided that is easy to mount on a bicycle. In this case, the rotor 4 can be fastened, for example, on a brake disk holder of a wheel hub, so that it rotates with the hub body. In this way, conventional bicycles can be retrofitted with an electric machine according to the invention.

FIG. 1 shows the coil 14 or the coil arrangement in its functional position. In the case where no electrical loads are driven or the battery is charged, the coil 14 or the coil assembly can be brought into the current position shown in Figure 2. For this purpose, the articulated arm 13 with respect to

Disc brake 2 swings so that the operative engagement between the

Permanent magnet 10 or 12 and the coil 14 and the coil assembly is repealed. This pivoting takes place about a pivot axis 16, wherein the Pivoting movement is controlled by a Schwenkaktor 18, which is operated in one embodiment by the driver or merely to limit the

Swivel angle serves.

Of course, instead of a standard disc brake holder 2, another suitable receptacle for the coil 14 or the coil arrangement can be selected.

FIG. 3 shows a perspective partial view of a practical second one

Embodiment of an electric machine 101, which is integrated directly into a brake system of a bicycle. In the middle of FIG. 3, a wheel hub 120 is clamped in dropouts 122 of a front fork 103 of the bicycle. At one in Figure 3 left

Immersion tube of the front fork 103 is arranged in the region of a lower end portion of an arm-like configured standard disc brake receptacle 102. At this adapter 124 is attached and fastened by screws (not shown). The adapter 124 is a standard part and serves for proper positioning of a brake caliper 126 relative to a brake disc 128. The type and size of the adapter 124 is selected as a function of the diameter of the brake disc 128. By replacing the brake disk 128 and the adapter 124 is an adaptation of

Braking power to a driving behavior, a weight of the driver or a use of the bicycle allows.

Two caliper feet 130 (only one shown) of the caliper 126 are penetrated by screws 132 (only one shown), via which the caliper 126 is attached to the adapter 124. On the brake caliper 126 are on both sides of the brake disc 128 two

Brake cylinder 134 (only one shown) arranged, which can be acted upon by a pressure medium in Fig. 3 only partially shown hydraulic line 136.

The electrical machine 101 shown in Figure 3 has a frame-fixed, the rotor 104 on both sides embracing coil housing 1 15, in which two coils are received 1 14 and protected against moisture and contamination. The electric machine further has a rotor 104, on which circumferentially distributed a plurality of permanent magnets 1 10, 1 12 is arranged. The circular cylindrical permanent magnets 1 10, 1 12th consist of solid material and are each inserted into a recess on the outer circumference of the rotor 104 and glued therein. The rotor 104 is formed substantially as a disk-shaped circular ring.

The coil housing 1 15 with the coils 1 14 received therein is not attached directly to the standard disc brake receptacle 102, but via two screws 138 on an integrally formed with the caliper 126 mounting tab 140. The mounting tab 140 is on this side facing the viewer

Inner surface 129 of the brake disc 128 is arranged. About this inner surface 129 and a (not shown) Einspeichung the front wheel is a radially extending to the rotation axis 121 annular space, hereinafter referred to as inner annulus, limited, which is the electric machine 101 as space available. The inner annular space is wider in the direction of the rotation axis 121 than an outer annular space, which is delimited by an outer surface of the brake disk 128 facing away from the observer and a plane parallel thereto, which touches the standard disk brake receptacle 102. Due to its greater width, the inner annular space offers the advantage that the permanent magnets 1 10, 1 12 rotating around it can be made comparatively wide and compact, which is in comparison to more planar designs

Permanent magnets (see 210, 212 of the following embodiment of Figure 4) results in a higher quality of the magnetic flux. With its higher quality is connected advantageous that the necessary for a given performance of the electric machine 101 magnetic mass is smaller. The arrangement of the coils 1 14 and the permanent magnets 1 10, 1 12 in the interior annulus thus contributes to a low weight of the electric machine 101 and thus of the bicycle. Another advantage of this arrangement is that the structural design of the rotor 104 and the

Permanent magnet 1 10, 1 12 with increasing size of the available space is simpler and less expensive and a lesser distance of a spanned to a bicycle longitudinal axis and a bicycle vertical axis center plane low on a neutral handling of the bicycle. More compact

Permanent magnets are also shock-resistant and temperature-resistant.

The coil housing 1 15 of the electric machine 101 has a groove-like

Recess 1 17, which are fastened while driving by the rotor 104 on the Permanent magnet 1 10, 1 12 during the rotation of the wheel with a

Angular velocity of the wheel is traversed. A first of the coils 1 14 is in an edged, arranged in Figure 3 above portion of the coil housing 1 15, the second of the two coils 1 14 in a bottom in Figure 3, rounded

Section of the coil housing 1 15 arranged. The edged shape of the upper portion of the bobbin case results from the fact that in addition to the upper coil 1 14 a supply electronics of both coils 1 14 is added. The two coils 1 14 extend saddle-like on both sides of the above-described groove-like recess 1 17, so that the permanent magnets 210, 212 are encompassed when passing through the recess 1 17 of the coils 1 14 on both sides without contact. Compared with a one-sided arrangement of the coils, this enables an increased power density of the electric machine 101.

Parallel to the hydraulic line 136, and thus with efficient use of the

Installation space, two power lines 146, 148 (only partially shown) arranged. About them the electrical load to be supplied via the electric machine 101 or the rechargeable battery can be supplied with power.

Brake disk 128 is attached to a central aluminum bracket 142 by six screws (not shown). In addition to the attachment meet the

Screw the function of a thermal decoupling, which is necessary because the brake disc 128 can reach a temperature up to 800 ° C. For better cooling and weight reduction, the brake disc 128 recesses 150. The central aluminum bracket 142 is attached to a standard brake disc mount which in turn is bolted to the wheel hub 120. Also, the rotor 104 is attached to the central aluminum bracket 142 with a plurality

Bolts 144 attached.

Figure 4 shows a third embodiment of a rotor 204 of an electric machine of a bicycle in a partial side view. Shown is an outer side of the rotor 204 and a standard brake disc 228, wherein a hub 220 extends rearwardly into the viewing plane. On a presentation of the

Front fork, the spokes and a brake system or the caliper and the Standard disc brake mount has been omitted for the sake of clarity. This is associated with that on a representation of the associated coil or their

Coil housing of the electric machine is dispensed with.

The flat, disc-shaped rotor 204 carries on a side facing the viewer, a plurality of permanent magnets 210, 212 which, unlike in the second

Embodiment according to Figure 3, are arranged in an outer annular space, which is bounded by an outer surface 229 of the rotor 204 and a plane arranged parallel thereto, which is tangent to a disc brake mount (not shown). This outer annular space is narrow in the direction of an axis of rotation of the front hub 220 compared with the inner annular space according to FIG. This is the reason why the permanent magnets 210, 212 arranged on the rotor 204 and rotating with it are flat. In order to use the cramped space of the outer annular space even more efficient, the rotor 204 carries next to the permanent magnets 210, 212 and the brake disc 228. He thus fulfills a dual function and it is eliminated over the previous

Embodiments in which the permanent magnets and the brake disc are each held separately, a component.

In order to thermally decouple the permanent magnets 210, 212 from the hot brake system or brake disk 228, the rotor 204 and the

Brake disc 228 two-piece. A firm connection between the two takes place via rivets 256. The rivets 256 preferably have a poor thermal conductivity and / or between the brake disk 228 and the rotor 204 are in the region of the rivet 256

Elements with poor thermal conductivity provided. The rotor 204 is made of aluminum and is on a standard six-hole recording hub 220 over

Screws 252 attached.

The permanent magnets 210, 212 are fan-shaped around the hub 220 on the rotor 204. The permanent magnets 210, 212 abut one another flush with their longitudinal sides. In order to fill up the available outer surface 229 as closed as possible with permanent magnets 210, 212 and thus to achieve the highest possible quality of the voltage that can be generated and the highest possible energy density, it proves to be advantageous to oppose the permanent magnets 210, 212 as shown to arrange a radial direction employed. The trapezoidal shape of the permanent magnets 210, 212 allows a dense coverage of the outer surface 229 as possible. The permanent magnets 210, 212 arranged on the rotor 204 are inserted in a plastic matrix 254, but are not covered with plastic on their side facing the observer. Alternatively and / or additionally, for the purpose of better protection, they may be surrounded by the plastic matrix and / or overmolded.

Notwithstanding the embodiments shown, an electric machine according to the invention may have more than one or two coils. The higher a number of coils, the higher the achievable quality of the voltage generated and the higher the energy density. Preferably, the number of coils used is two, three or four. In this case, a successive arrangement of the coils along or parallel to an orbit of the permanent magnet is preferred. The more coils are arranged in succession, the higher is an achievable

Quality of the generated voltage. The use of only one coil, however, represents a device-technically simple and cost-effective solution, but with reduced energy yield and lower quality of the voltage.

Regardless of the embodiments shown, the coil or coils may be attached directly to the disc brake mount or attached adapter.

Alternatively or in addition to the embodiments shown, the

Standard disc brake instead to be attached to the fork on another part of a frame of the bicycle or the vehicle.

Deviating from the embodiments shown, the

Permanent magnets to be enveloped by a plastic layer.

Notwithstanding the embodiments shown, the rotor can

Consist of plastic or have this. This is also true when the rotor, as shown in the third embodiment, carries the brake disc, and must withstand high braking forces and high temperatures. Disclosed is an electric machine for a human-powered vehicle, preferably a bicycle, in which rotate a plurality of permanent magnets with a wheel hub and a coil frame or forked is arranged.

LIST OF REFERENCE NUMBERS

1 ; 101 electric machine

2; 102 standard disc brake ref

3; 103 front fork

4; 104; 204 rotor

6 hub axle

8 recesses

10; 1 10; 210 permanent magnet

12; 1 12; 212 permanent magnet

13 articulated arm

14; 1 14 coil

16 pivot axis

18 swivel actuator

1 15 bobbin case

120; 220 wheel hub

121 rotation axis

22 dropouts

124 adapters

126 caliper

128; 228 brake disc

129 inner surface

130 caliper foot

132 screw

134 brake cylinder

136 hydraulic line

138 screw

40 mounting bracket

142 Central aluminum bracket

144 screw

146, 148 power line

150 recess 229 Outer surface 252 Screw 254 Plastic matrix 256 Rivet

Claims

claims

1 . Electric machine for a human powered vehicle, preferably one

Bicycle, wherein at least one coil (14; 1 14) and at least one

Permanent magnet (10, 12; 1 10, 1 12, 210, 212) for inducing a voltage in the coil (14; 1 14) are moved relative to each other, wherein the coil (14; 1 14) or the permanent magnet (10, 12 1 10, 1 12, 210, 212) is rotatable with one wheel of the vehicle and the other component is arranged frame-mounted or fork-fixed, characterized in that the permanent magnets (10, 12; 1 10, 1 12, 210, 212) rotatably secured to a wheel hub (120; 220) and the at least one coil (14; 1 14) is fixed to the frame.

2. Machine according to claim 1, wherein a plurality of permanent magnets (10, 12;

1 10, 1 12; 210, 212) is attached to a disc-shaped rotor (4; 104; 204) and the at least one spool (14; 1 14) is attached to a standard disc brake mount (2; 102).

3. Machine according to claim 2, wherein two coils (14) or two

Coil arrangements are arranged on both sides of the rotor (4).

4. Machine according to claim 2 or 3, wherein the at least one coil (14) via an articulated arm (13) on the standard disc brake mount (2) is fixed, wherein the articulated arm (13) from a functional position in one

Power release position is pivotable, in which the at least one coil (14) is out of operative engagement with the permanent magnets (10, 12).

5. Machine according to claim 4, wherein end positions of the articulated arm (13) are limited by stops.

A machine as claimed in any one of claims 2 to 5, wherein the rotor (4; 104; 204) is fixed to a brake disk mount of the wheel hub (120; 220).

7. Machine according to one of the preceding claims, wherein the coils (1 14) in a circumferential direction of the permanent magnets (1 10, 1 12)

are arranged consecutively.

8. Machine according to one of the claims 2 to 7, wherein the rotor consists mainly or entirely of plastic.

9. Machine according to one of the claims 2 to 8, wherein the

Permanent magnets (1 10, 1 12, 210, 212) are integrally connected to the rotor (104, 204).

10. Machine according to one of the claims 2 to 9, wherein on the rotor (204) a brake disc (228) is attached.

1 1. Machine according to one of the claims 2 to 10, wherein the at least one coil (1 14) extends on both sides of the rotor (104).

12. Machine according to one of the preceding claims, wherein the

Make permanent magnets (210, 212) flat transverse to a direction of rotation.

13. Machine according to one of the claims 2 to 12, wherein the

Permanent magnets (210, 212) are arranged substantially laterally on the rotor (204).

14. Machine according to one of the preceding claims, wherein the

Permanent magnets (1 10, 1 12) transversely to its direction of rotation at least partially an oval or a circular or polyhedron-shaped

Have cross-section.

15. Machine according to one of the preceding claims, wherein the

Permanent magnets (1 10, 1 12) are arranged substantially on an outer peripheral region of the rotor (104).