JP2006034901A - Electric wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric wheel of a form that a motor used for an electric wheelchairs or an electric bicycles is mounted within the hub of a wheel in which reduction of a price and the extending property of specifications are made possible by using a general-purpose motor. <P>SOLUTION: One or two or more general-purpose motors are mounted within the hub of the wheel so that they may be mostly parallel to the side face of the wheel, and the power is transmitted to a tire wheel via a pair of worm gears or bevel gears. Also, a one-way clutch is arranged between the worm gears or bevel gears and the hub of the wheel, and both electric and un-electric movements can be easily and independently performed. Further, in a control electric source for electric power supply, both manual and auxiliary movements become possible. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

Detailed Description of the Invention

[Technical field to which the invention belongs]
The present invention relates to an electric wheel for electric wheelchairs and bicycles driven by an electric motor.

[Conventional technology]
Conventional electric wheelchairs and bicycle electric wheels are generally equipped with one dedicated electric motor parallel to the wheel rotation axis and drive tires directly or via a reduction gear.

[Problems to be solved by the invention]
When a tire is directly driven by an electric motor according to a conventional technique, it is necessary to adopt a dedicated electric motor having a low rotation speed and a large torque, which is accompanied by an increase in shape and price.
In addition, when the power of the dedicated motor is transmitted to the tire via the speed reducer, there is still a problem that the number of gear stages of the speed reducer increases in order to obtain a low rotational speed and a large torque. The result was an increase in shape and price.
Furthermore, since a dedicated electric motor is used, it is difficult to cope with changes in specifications.

[Means for solving problems]
In order to solve the above problems, in the present invention, one or a plurality of general-purpose electric motors are accommodated in a hub of a wheel in a form substantially orthogonal to the rotational direction of the wheel, and combined with a pair of worm gears or bevel gears to Is transmitted to the wheel tires.
Further, a one-way clutch is interposed between the worm gear or bevel gear and the wheel hub so that power can be transmitted only when the electric motor is operating. In other situations, the wheel is free to rotate. In this way, both electric and non-electric operation can be supported.
Furthermore, in the present invention, a general-purpose electric motor is used to reduce the price of the wheel, and the number of electric motors to be mounted is changed so that it can easily cope with a change in wheel specifications.
Electric power is supplied to the motor through a pulse width control system or a frequency control system control power supply. Is the control performed by manually controlling the pulse width or frequency by the operator of a wheelchair or bicycle? Assisting the driver by automatically controlling the power supplied to the motor by detecting changes in the number of wheel rotations or the current flowing in the motor generated by the driver driving the driving wheel or pedal. I tried to make it.

[Embodiment of the Invention]
Next, the present invention will be specifically described with reference to the accompanying drawings.
FIG. 1 (a) is a schematic structural view of a hub portion of an electric wheel according to the present invention as viewed from the side.
In the figure, reference numeral 1 denotes a hub, reference numerals 2 and 2 'denote electric motors, and reference numeral 3 denotes a central axis of the wheel.
Reference numeral 4 indicates a worm wheel, and reference numerals 5 and 5 ′ indicate worms.
The worm wheel 4 and the worms 5 and 5 'are combined to form a set of worm gears.
Further, reference numerals 6, 6 ′, and 6 ″ denote spokes, and the spokes, which are not shown, are combined with the wheel 1 of a wheel on which a tire or a tube is mounted and the hub 1 to form a wheel.
In this description, the tire wheel (not shown) and the hub 1 are described as being joined by spokes. However, the hub 1 may be directly joined by increasing the diameter of the hub 1 or a frame-like joining material may be used. But of course it works in the same way.
[FIG. 1] (b) is a schematic view showing the internal structure of the hub 1 cut along a plane passing through the central axis of the wheel of one embodiment of the present invention.
As is apparent from the figure, the hub 1 is connected to the central axis 3 of the wheel via bearings indicated by reference numerals 8 and 9 so as to freely rotate around the central axis 3.
The hub 1 is coupled to the worm wheel 4 and rotates together.
The center shaft 3 is fitted to a wheelchair or bicycle frame (not shown) at both ends thereof, and is fastened and fixed to the frame by screws applied thereon and nuts (not shown). .
Reference numeral 7 denotes an electric motor support material.
The support member 7 is fixed to the center shaft 3 at the center, and the electric motors 2 and 2 ′ are fixed by a fixing material not shown.
Here, a case where a worm gear is used has been described, but in the case of a bevel gear, if a pair of bevel gears are mounted instead of a worm wheel and a worm, the same function can be achieved.
However, since the reduction rate may be low with only the bevel gear, it may be necessary to use an electric motor with a reduction gear.
Furthermore, although the embodiment using two electric motors is described here, the internal structure of the hub 1 is hardly changed even when the number of electric motors is one or when the number is increased to about six. It is possible to function.

[FIG. 2] (a) is a partial schematic view of a cross section of an embodiment of the one-way clutch used in the present invention, cut along a plane parallel to the central axis 3 of the wheel. 4 is a partial schematic view of a cross section cut along a plane perpendicular to the central axis 3. FIG.
As is apparent from the figure, the hub 1 is separated from the worm wheel 4, and the rotation axis of the hub 1 is superimposed on the rotation axis of the worm wheel 4.
On the rotating shaft of the worm wheel 4, a groove indicated by reference numeral 10 is provided in the rotating direction, and a steel ball indicated by reference numeral 11 is fitted in the groove 10.
[FIG. 2] As is apparent from FIG. 2B, the groove 10 is deep at the front end of the worm wheel 4 in the rotational direction, becomes an opening penetrating vertically, and is shallow at the rear end.
The central shaft 3 is provided with a shallow groove indicated by reference numeral 12, and a protrusion indicated by reference numeral 13 is provided at a part thereof.
Reference numerals 14 and 15 denote bearings mounted between the central shaft 3 and the worm wheel 4.
When the electric motor is activated, the worm wheel 4 rotates counterclockwise in the figure, and the steel ball 11 comes into contact with the projection 13, the steel ball 11 moves backward in the groove 10 and rides on the gradient portion of the groove 10 The upper part comes into contact with the inner surface of the rotating shaft of the hub, moves further rearward due to friction, and cannot move any more, so that the worm wheel 4 and the hub 1 are fixed and rotate together.
When the rotation speed of the worm wheel 4 becomes slower than the rotation speed of the hub 1 when the wheel stops, the steel ball 11 slides the gradient of the groove 10 into the opening at the tip, and the connection between the worm wheel 4 and the hub 1 is released. .
Therefore, when the motor is not operating, the worm wheel 4 and the hub 1 maintain a completely free relationship, and the wheels can freely rotate.
Here, the case where there is one steel ball 11 has been described, but it is also possible to use a plurality of steel balls, and it is also possible to use one or a plurality of steel columnar members. is there.

FIG. 3 shows a schematic diagram of a control power supply circuit used when the operator manually operates the electric wheelchairs or the electric bicycles equipped with the electric wheels of the present invention.
In the figure, reference numeral 20 denotes a general purpose pulse width control power supply integrated circuit, reference numeral 21 denotes a power supply terminal, reference numeral 22 denotes a reference voltage terminal, reference numeral 23 denotes a ground terminal, reference numeral 24 denotes a CT terminal (oscillation frequency setting). Capacitor connection terminal), 25 is an RT terminal (oscillation frequency setting resistor connection terminal), 26 is an F / B terminal (feedback terminal), and 27 is an output terminal.
Reference numeral 28 denotes a power supply battery, reference numeral 29 denotes an output power MOSFET, reference numerals 30, 32, and 33 denote resistors, reference numerals 31 and 34 denote variable resistors, and reference numeral 35 denotes a capacitor.
The oscillation frequency of the integrated circuit 20 is determined by the values of the resistor 33, the variable resistor 34, and the capacitor 35.
Further, the ON / OFF ratio of the output pulse is determined by the voltage of the F / B terminal 26.
Therefore, it is possible to easily perform pulse width control or frequency control by attaching levers or the like to the variable resistors 31 and 34 and operating them by an operator of an electric wheelchair or electric bicycle to change the value of the variable resistor. It is possible to control the power supplied to the motor and control the speed.
If the variable resistor 34 is changed to a fixed resistor when performing pulse width control, and the variable resistor 31 is changed to a fixed resistor when performing frequency control, the possibility of malfunctioning is reduced.
The variable resistors 31 and 34 can be replaced with a method of switching a switch by combining several fixed resistors and corresponding switches.
In addition, since the general-purpose integrated circuit 20 has different specifications depending on the manufacturer, it goes without saying that it must be used in accordance with the specifications.

[FIG. 4] shows that when a driver of an electric wheelchair or an electric bicycle equipped with electric wheels according to the present invention drives a driving wheel or a pedal to change the speed, the speed is detected and automatically FIG. 3 is a schematic diagram of a control circuit for assisting a driver's operation by controlling electric power supplied to the electric motor.
Most of the reference numerals of the respective parts in the circuit diagram are the same as those in FIG.
In FIG. 4, instead of the variable resistors 31 and 34 used in FIG. 3, a speed detection coil indicated by reference numeral 36, a rectifier indicated by reference numeral 37, a capacitor indicated by reference numeral 38, and a reference numeral 39. The resistors shown are added.
The speed detection coil 36 can be easily formed, for example, by attaching a small piece of a permanent magnet to the side surface of the worm wheel 4 and arranging a winding on the motor holding member 7 close to the rotating surface.
The voltage of the electric power generated in the speed detection coil 36 varies depending on the rotation speed of the worm wheel 4.
The electric power is rectified by the rectifier 37, stored in the capacitor 38, converted into DC power, and applied to the F / B terminal 26 via the resistor 32.
The rectified power works in a direction to lower the voltage of the F / B terminal 26 and works in a direction to expand the width of the output ON pulse.
Therefore, when the driver increases the speed by driving the driving wheel or the pedal, the power supplied to the electric motor 2 is increased, and the operation of the driver is assisted.
When the driver operates the brake or the like to reduce the speed, the reverse phenomenon occurs, the power supplied to the electric motor 2 is reduced, and similarly, the driver operates in a direction that assists the operator's operation.
A resistor denoted by reference numeral 39 is combined with the capacitor 38 to determine the time multiplier of the circuit and to make the operation of the circuit smooth.
Further, when the voltage generated by the speed detection coil 36 increases, the rectifier indicated by reference numeral 37 ′ becomes conductive, the voltage at the F / B terminal 26 stops decreasing, prevents further increase in supply power, and provides the maximum speed limiting function. Demonstrate.
When a circuit including the speed detection coil 36 is connected to the circuit of the RT terminal 25 instead of the variable resistor 34, the frequency can be increased or decreased so as to assist the operator's operation. .
In this case, the lower end of the resistor 32 is directly connected to the ground wiring.
Here, the circuit that directly transmits the voltage generated in the rotation speed detection coil 36 to the F / B terminal 26 has been described. However, the operation characteristics of the control power supply can be further improved by interposing an amplification circuit having appropriate characteristics. It can be made appropriate.

[FIG. 5] is a schematic diagram of a control power supply circuit for automatically assisting an operator of an electric wheelchair or electric bicycle by detecting a current flowing through the electric motor 2 of the electric wheel according to the present invention. is there.
It is the same as the previous item that most of the reference numerals in the figure are the same as in FIG.
In the figure, reference numeral 40 denotes a current detection resistor connected between the source terminal of the power MOSFET 29 and the ground wiring of the circuit.
The current value flowing through the resistor is the same as the current value flowing through the electric motor 2.
The value of the current flowing through the electric motor 2 is large when the rotation speed of the motor is low, and decreases as the rotation speed increases.
The electric power is rectified by a rectifier indicated by reference numeral 41, accumulated in a capacitor indicated by reference numeral 38, and transmitted to the F / B terminal 26 via the resistor 32.
When an operator of an electric wheelchair or an electric bicycle drives and accelerates a driving wheel or a pedal, the number of revolutions of the electric motor 2 increases, and the current flowing through the electric motor 2 decreases.
As a result, the voltage generated in the resistor 40 is decreased, the voltage applied to the F / B terminal 26 is decreased, the ON pulse width of the driving power is expanded, and the power supplied to the electric motor 2 is increased. Work to assist the person.
When the pilot decelerates by operating a brake or the like, the circuit operates in the reverse direction, and it is the same that assists the pilot's operation. .
The rectifier and resistor 43 indicated by reference numeral 42 have a function of correcting a voltage drop caused by the rectifier 41.
The resistor 32 has a function of defining the minimum voltage of the F / B terminal 26 and a function of limiting the maximum speed of the electric wheelchairs or electric bicycles.
When this circuit is connected between the resistor 33 connected to the RT terminal 25 and the ground wiring, the control power source performs the frequency modulation operation, controls the electric power of the electric motor 2, and assists the driver. is there.
Here, the circuit for transmitting the voltage from the current detection resistor 40 directly to the F / B terminal 26 has been described. However, if an amplifier circuit having an appropriate function is interposed, a more appropriate control operation can be performed. It becomes possible.

[The invention's effect]
As described above, according to the present invention, it is possible to effectively use a limited hub space by mounting one or more general-purpose small electric motors so as to be orthogonal to the rotational direction of the wheels. It is possible to realize low-priced and high-performance electric wheels, and by increasing or decreasing the number of motors, it is possible to realize electric wheels that can easily adapt to specification changes without changing the structure of the device. Things became possible.
In addition, the adoption of a one-way clutch with a simple structure and a small shape has made it possible to realize an electric wheel that can achieve both electric and non-electric operation.
In addition, it is possible to realize an electric wheel that can control the control power supply manually and can perform automatic auxiliary operation.

It is the schematic structure figure which looked at the hub part of the wheel from one side showing one example of the electric wheel of the present invention. 1 is a schematic structural view of a cross section viewed from a plane parallel to a central axis of a wheel, showing an embodiment of an electric wheel of the present invention. It is the schematic structure figure of the cut surface which looked at one Example of the one way clutch used for the electric wheel of the present invention from the field parallel to the central axis of a wheel. It is the schematic structure figure which looked at one Example of the one way clutch used for the electric wheel of the present invention from the cut surface perpendicular to the central axis of a wheel. It is a schematic circuit diagram which shows one Example of the control power supply circuit for manual operation used for the electric wheel of this invention. It is a schematic circuit diagram which shows one Example of the control power supply circuit of a rotation speed detection system used for the electric wheel by this invention. It is a schematic circuit diagram which shows one Example of the control power supply circuit of the electric current detection system used for the electric wheel by this invention.

Explanation of symbols

1 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub 2, 2 ′ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Electric motor 3 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Center shaft 4 ・ ・ ・ ・ ・ ・········· Warm foil 5,5 '········· Worms 6, 6', 6 "····· Spoke 7 ············· Support Materials 8, 9 ... ・ ・ ・ ・ ・ Bearing 10 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Groove provided on worm wheel rotating shaft 11 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Steel ball 12 ··············································· 13・ Bearing 20 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Integrated circuit for pulse width control 21 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Power supply terminal 22 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Reference voltage terminal 23・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Ground terminal 24 ・・ ・ ・ ・ ・ ・ ・ ・ ・ CT terminal 25 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ RT terminal 26 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ F / B terminal 27 ・ ・ ・ ・ ・ ・ ・ ・... Output terminal 28 ... Battery 29 ... Power MOSFET
30, 32, 33 ... Resistors 31, 34 ... Variable resistors 35, 38 ... Capacitors 36 ... Rotation speed detection coil 37, 37 '... Rectifier 39, 43 ... Resistor 40 ... Current detection resistor 41, 42 ... ·······rectifier

Claims (4)

One or a plurality of electric motors and a set of worm gears or bevel gears, which are built in the hub of the wheel and are mounted so as to be orthogonal to the rotation direction of the wheel, transmit the power of the electric motor to the tire. Electric wheelchairs and electric wheels for electric bicycles. The electric wheel according to claim 1, wherein the hub of the wheel and a worm gear or a bevel gear are joined via a one-way clutch. The motor is driven by a pulse width control or frequency control type control power supply, and the speed can be changed by controlling the pulse width or frequency of the control power supply by manual operation of the operator of the electric wheelchair or electric bicycle. The electric wheel according to claim 1 characterized by the above. The electric motor is driven by a pulse width control or frequency control type control power source, and the driver of the electric wheelchairs or electric bicycles drives a driving wheel or a pedal to accelerate the vehicle and operates a brake or the like. When the vehicle is decelerated, the electric wheel according to claim 1, wherein the operation of the driver is assisted by detecting an increase or decrease in the number of rotations of the wheel or an electric current flowing through the electric motor.

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