DE29803665U1 - Drive for wheelchair with an external rotor motor - Google Patents

Description

Drive for wheelchair with an external rotor motor

The invention relates to a drive for a wheelchair with a gearless electric direct current motor with an external rotor, which in the position of use is arranged as a hub motor in the center of a wheel of the wheelchair or essentially forms the wheel, with a brake rotor connected to the rotor designed as the external rotor in a rotationally fixed manner at least in the circumferential direction, which can be fixed in front of an armature disk of an electromagnetic spring pressure brake in the de-energized state against rotation and can be released electromagnetically or mechanically against the pressure force of springs.

A comparable drive is known, for example, from EP 0 699 550 Bl. The external rotor of the electric direct current motor is connected in a rotationally fixed manner to an axis that rotates with it and is mounted on a ball bearing opposite a brake housing. The electromagnetically released spring pressure brake is arranged on the side of this drive motor that faces the wheelchair in the position of use. The brake housing has an important additional function, because the stator of the direct current motor is fixedly connected to the wheelchair via this brake housing. The manually or electromagnetically released spring pressure brake is therefore also located on the side of the drive motor.

note \ LA000040

Spring-loaded brake between the DC motor or drive motor and the wheelchair, so that an operating lever for manually releasing or venting the spring-loaded brake must be accommodated within the wheelchair frame. On the one hand, it is hardly accessible there for the wheelchair user himself, and on the other hand it prevents the wheel with its drive from being quickly and easily detached from the wheelchair. However, such detachability of the wheel(s) is very often desirable or even essential, especially with wheelchairs, if the wheelchair is to be transported in a motor vehicle - if possible by the wheelchair user himself - and is to be able to be loaded and unloaded, because such motor vehicles often have confined spaces, which make it necessary to quickly and easily remove the wheels from the wheelchair.

It may also be necessary to release the brake manually, even by the wheelchair user himself, if, for example, the batteries serving as the power source for the DC motor are exhausted and muscle-powered propulsion is required.

Furthermore, such a drive for a wheelchair is known from WO 93/15546. The motor axle is also the axle of the driven wheel, so that in this case too the drive motor is arranged in the center of the wheel. This drive is also gearless, but the bearing axle is fixed and connected to the frame of the wheelchair. A braking device is not provided within this motor.

The invention is therefore based on the object of creating a drive 0 for wheelchairs of the type mentioned at the beginning, in which a spring pressure brake is provided, the manual ventilation of which is simplified and can also be carried out without any problems by the wheelchair user himself, whereby the wheels of the wheelchair together with their drive can also be easily and quickly removed and brought back into the position for use.

To solve this problem, the drive for wheelchairs with external rotor motor mentioned at the beginning is characterized in that the external rotor is rotatably mounted on a fixed, non-rotating bearing axis, which bearing axis can be locked by means of a quick-release fastener

'■5 is detachably attachable or attached to the frame of the wheelchair and contains a channel or similar for the electrical line used to supply power to the electromagnetic release device of the spring-loaded brake, and that the stator of the DC motor is arranged on the side of the external rotor facing the wheelchair in the position of use or assembly and the brake disc with the spring-loaded brake is arranged on the side of this external rotor facing away from the wheelchair. Because the plug-in or bearing axle does not rotate, it is very easy to connect it to the wheelchair using a quick-release fastener, as is the disconnection, so that the wheelchair owner can also easily assemble and disassemble the wheels himself. The spatial arrangement of the spring-loaded brake does not hinder such quick assembly or disassembly.

In addition, this results in a particularly advantageous arrangement for a hand lever used to manually release the spring-loaded brake, in that it can be arranged on the side of the wheel and drive facing away from the wheelchair. This means that such a hand lever does not hinder the quick assembly of the wheel and, above all, the accessibility of this hand lever is improved, so that the wheelchair user himself can reach it without any problems. He only needs to reach over the wheelchair wheel, which he does when moving the wheelchair manually. This enables him to move the wheelchair using muscle power if this were necessary, for example, due to exhaustion of the power source for the DC motor.

The bearing axle can be a hollow axle, in whose inner longitudinal cavity

the electrical cable runs to the brake release magnets. The inner longitudinal cavity is thus used as the previously mentioned channel for laying the electrical cable.

This also results in a further design option in that a plug is arranged in the inner longitudinal cavity of the bearing axle at the end facing the wheelchair, from which the electrical line leads to the brake and which can be coupled to its mating contacts to connect the power source on the wheelchair when the wheel is put on the wheelchair. The assembly and disassembly of the wheel with its drive is therefore made considerably easier because the electrical contact is made at the same time as it is put on and, conversely, when the wheel with its bearing axle is removed, the electrical connection is broken by simultaneously removing the plug without any special measures being required in this regard. Attaching the wheel simultaneously means establishing the electrical connection to the power source, whereby not only the electrical cable for the ventilation of the spring-loaded brake, but also the one for the actual drive motor can be arranged and coupled in the same way, in that the electrical supply line to the power electronics of the DC motor can also run in the inner longitudinal cavity of the bearing axle and be connected to the plug in a suitable manner."

' It is expedient if the stator of the direct current motor encloses a cavity in which the control for the brake magnet is arranged, and if the electrical supply line through the bearing axis exits the bearing axis through a radial opening 0 and leads to this control, and if the line for the control pulses enters the bearing axis radially in the opposite direction, in particular in the same opening, and leads to the electromagnet. The control for the brake magnet can therefore expediently be housed within the drive, 5 so that it remains with the

Spring pressure brake connected.

The external rotor of the DC motor can form an annular space concentrically to its bearing and bearing sleeve, which engages the fixed bearing axis, on the outer edge of which in the radial direction the winding of the stator is arranged and on the inner edge of which the braking device is arranged. In this way, the space required for the winding in the axial direction can be used at the same time radially further inward to accommodate the spring-loaded brake, without the axial size of the drive increasing or increasing significantly for this.

The brake rotor can have a central opening with which it fits onto a driver shoulder of the external rotor, whereby a non-circular, in particular polygonal shape can be provided for the driver shoulder and the inner opening of the brake rotor. This means that correspondingly high torques, i.e. high braking forces, can be transmitted. At the same time, relatively low shear forces arise in the circumferential direction and, in addition, the attachment of a tongue and groove and the assembly and production required for this are avoided.

At the same time, this type of rotary coupling allows the brake disc or brake rotor to be moved relative to one another in the axial direction in a simple manner, which is very small but necessary for the brake to function properly.

The bearing axle can have an adapter and can be coupled with a DC motor and wheel to a wheelchair that was not previously electrically powered.

0 This advantageously provides the opportunity to

to convert non-motorized wheelchairs by providing a power source on the wheelchair itself and replacing the existing wheels or one of the existing wheels with the drive according to the invention.
35

An embodiment of the invention is described in more detail below with reference to the drawing. It shows, in a partially schematic representation:

Fig. 1 shows a drive according to the invention as part of a wheel, the spokes of such a wheel being indicated with broken lines, shortly before being connected to a quick-release fastener arranged on a wheelchair frame and
10

Fig. 2 is a longitudinal section of the drive according to Fig. 1 in the coupled position with the quick release.

A drive, designated as a whole by 1, has a gearless electric direct current motor with an external rotor 2, on whose outer circumference in the exemplary embodiment anchoring points 3 are arranged for spokes 4 of a wheel of a wheelchair that is driven by this drive 1. The direct current motor is therefore arranged in the position of use as a hub motor in the center of a wheel of a wheelchair, but could also form the wheel itself if it is of the appropriate size.

The external rotor 2 carries a hollow ring 4 on the inside and on this magnets 5, which are connected in the usual way to an armature and a

fe5 winding 6 of a stator 7. The armature carrier 8 is located approximately opposite the radial area 2a of the external rotor.

A brake rotor 9 is connected in a rotationally fixed manner 0 in the circumferential direction or direction of rotation to the rotor of the electric motor, which is designed as an external rotor 2, and can be secured against rotation by an armature disk or brake pressure plate 10 of an electromagnetic spring-loaded brake when the current is off and can be released electromagnetically or mechanically against the pressure force of springs 11. In Fig. 2, the brake coil 12 can be clearly seen, which electromagnetically attracts the armature or brake pressure plate (10) when the current is applied.

while in the de-energized state it is pressed by the springs 11 against the brake rotor 9 so that the latter exerts its braking effect.

It is also possible to release the brake and in particular the brake rotor 9 mechanically using a hand lever 13. If the hand lever 13 is pivoted, a rotary disk 14 with a groove 15 is simultaneously rotated, which groove engages over at least one ball 16 that is arranged in the brake coil housing 17 and, due to the groove 15 decreasing in depth, moves the rotary disk 14 away from the brake coil housing 17 when it is rotated in the axial direction. The rotary disk 14 is connected to a plate 18, which is engaged by tension bolts 19 that are connected to the brake pressure plate 10 and can lift the latter off the brake rotor 9 against the force of the spring 11, so that the pivoting of the hand lever 13 also releases the brake.

The external rotor 2 is mounted on a fixed, non-rotating bearing axle 20 so that it can rotate using ball bearings 21, and this bearing axle 20 can be detachably attached (Fig. 1) or attached (Fig. 2) to the frame 23, which is only shown in Fig. 1 with respect to a frame section, using a quick-release fastener 22. The quick-release fastener provides a coupling pawl 25 loaded with a spring 24, which in the assembled position engages in a recess 26 in the bearing axle 20 and thus creates the axial connection. In addition, a sleeve-shaped adapter 27, which is connected to the frame part 23 of the wheelchair, ensures radial fixing.

0 To release this quick-release fastener 22, the latch only needs to be pivoted against the force of the spring 24, whereby its engagement in the recess 2 6 is released, after which the bearing or plug-in axle 2 0 can be pulled out of the adapter 27.

The stator 7 is located on the in use or

Assembly position on the side of the outrunner 2 facing the wheelchair, while the brake disc or the brake rotor 9 with the spring pressure brake and the hand lever 13 are arranged on the side of this outrunner 2 facing away from the wheelchair, so that the assembly and disassembly of the drive 1 and thus the wheel of the wheelchair is not hindered by the brake and the hand lever 13.

In Fig. 2 it can also be seen that the bearing axis 20 contains a channel 28 designed as a central inner longitudinal cavity, which accommodates electrical lines 29, in particular the power supply to the electromagnetic ventilation device of the spring-loaded brake.

Since the bearing axle 20 does not rotate, the electrical line 29 can be fed to the brake at this point without any problems and without hindrance, without affecting the rotation of the wheel and its drive 1 in any way. By designing the bearing axle 20 as a hollow axle, in whose inner longitudinal cavity the electrical lines 29 run, this axle is given an additional function.

In Fig. 2 it can also be seen that in the inner longitudinal cavity of the bearing axle 20 at the end facing the wheelchair in an extension 30 of this inner longitudinal cavity a plug 31 is arranged and fitted, from which the electrical line 29 leads to the spring pressure brake and which, when the wheel is put on the

Iß5 wheelchair or.. when inserting the bearing axle 2 0 into the adapter 27 simultaneously comes into contact with its counter contacts or a counter plug, so that by plugging or connecting it

■ the drive 1 on the wheelchair is coupled to the power source located on it. The corresponding wheelchair wheel is thus simply inserted with its plug-in or bearing axle 20 into the adapter 27 until the latch 2 5 engages in the recess 2 6, which simultaneously creates the electrical contact for the drive itself and for its spring-loaded brake.

5 The stator 7 of the DC motor encloses a cavity 32,

in which the control 33 for the brake magnet 12 and also the power electronics for the DC motor are housed. In Fig. 2, it can be seen that the electrical supply line 29 for the DC motor and/or the brake magnet 12 exits the bearing axis 20 through a radial opening 34 and leads to the control 33 or power electronics. The line for the control pulses can then enter the bearing axis 20 radially in the opposite direction through the same opening and continue to the electromagnet 12. This is possible without any problems because the bearing axis 20 and the stator 7 as well as the controls and electronic devices housed in it are fixed.

From the above description it follows that the inner longitudinal cavity of the bearing axis 2 0 also contains the electrical supply line to the power electronics of the DC motor.

From Fig. 2 it can also be seen that the external rotor 2 of the DC motor of the drive 1 forms an annular space concentrically to its bearing, which engages the fixed bearing axis 20 via the ball bearings 21 and is designed as a bearing sleeve 35, on the outer boundary of which in the radial direction the winding 6 of the stator 7 is arranged on the outside and the braking device on the inside. This braking device is located between this outer boundary and the inner boundary formed by the bearing sleeve 35, so that the winding 6 and the braking device can be arranged as far as possible between two planes, thus achieving the smallest possible axial length of the drive 1. The axial space required by the winding 6 can be largely used to accommodate the brake.

The brake rotor or the brake disk 9 has a central opening with which it fits onto a driver shoulder 3 6 of the external rotor, which is arranged on the bearing sleeve 35. The 5 inner opening of the brake rotor 9 and this driver shoulder 3 6 can form a

have a non-circular, preferably polygonal shape, in order to allow axial displacement of the brake rotor 9, but at the same time to be able to transmit a high torque in the direction of rotation.

Finally, it should be mentioned that the bearing axle 20 could have an adapter in a manner not shown in detail or the adapter 27 shown is designed in such a way that a wheel of a previously non-electrically driven wheelchair can be connected to the drive 1 with

. can be replaced with the corresponding wheel. This means that wheelchairs that have not yet been powered can be converted and fitted with drive 1.

fc /Claims

Claims (9)

Expectations 1. Drive (1) for a wheelchair with a gearless electric direct current motor having an external rotor (2), which in the position of use is arranged as a hub motor in the center of a wheel of the wheelchair or essentially forms the wheel, with a brake rotor (9) being connected in a rotationally fixed manner at least in the circumferential direction to the rotor designed as the external rotor (2), which brake rotor is actuated by an armature disk in the de-energized state (10) of an electromagnetic spring pressure brake can be secured against twisting and can be released electromagnetically or mechanically against the pressure force of springs (11), characterized in that the external rotor (2) is rotatably mounted on a fixed, non-rotating bearing axis (20-), which bearing axis (20) can be detachably attached or is attached to the frame or chassis (23) of the wheelchair by means of a quick-release fastener (22) and contains a channel (28) or the like for the electrical line (29) serving to supply power to the electromagnetic release device of the spring pressure brake, and that the stator (7) of the direct current motor is arranged on the side of the external rotor (2) facing the wheelchair in the use or assembly position and the brake disk (9) with the spring pressure brake is arranged on the side of this external rotor (2) facing away from the wheelchair. th 5 2. Drive according to claim 1, characterized in that a
for manual release of the spring pressure brake
Hand lever (13) on the side facing away from the wheelchair
of the wheel and the drive (1). 0 3. Drive according to claim 1 or 2, characterized in that the bearing axle (20) is a hollow axle in whose
Inner longitudinal cavity the electrical cable (29) to the
brake release magnet. 5 4. Drive according to one of claims 1 to 3, characterized characterized in that in the inner longitudinal cavity of the bearing axle (20) at the end facing the wheelchair a plug (31) is arranged, from which the electrical line (29) leads to the brake, and which when the wheel is put on the wheelchair can be coupled at the same time with its counter contacts for connection to the power source located on the wheelchair. 5. Drive according to one of claims 1 to 4, characterized in that the stator (7) of the DC motor encloses a cavity (32) in which the control (33) for the brake magnet (12) is arranged, and that ^ the electrical supply line (29) through the bearing axis (20) exits the bearing axis (20) through a radial opening (34) and leads to this control (33), and that the line for the control pulses enters the bearing axis (20) again in the opposite direction radially, in particular through the same opening, and leads to the electromagnet. 6. Drive according to one of claims 1 to 5, characterized in that the electrical supply line (29) to the power electronics of the DC motor also runs in the inner longitudinal cavity of the bearing axis (20). 7. Drive according to one of claims 1 to 6, characterized in that the external rotor (2) of the DC motor forms an annular space concentrically to its bearing and bearing sleeve (35) engaging the fixed bearing axis (20), on the outer boundary of which in the radial direction the winding (6) of the stator (7) is arranged and on the inner boundary of which the braking device is arranged. 8. Drive according to one of claims 1 to 7, characterized characterized in that the brake rotor (9) has a central opening with which it fits onto a driver shoulder (36) of the outer rotor (2), wherein a non-circular, in particular polygonal shape is provided for the driver shoulder (36) and the inner opening of the brake rotor (9). 9. Drive according to one of claims 1 to 8, characterized in that the bearing axle (20) has an adapter (27) and can be coupled with a direct current motor and wheel to a previously non-electrically driven wheelchair.