JPS6120221B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power transmission device applicable to, for example, a bicycle.

In general, when the driving shaft of an electric motor, etc. is connected to a load directly or through a reduction gear, depending on the size of the power load on the motor, even if the power is turned on to start the motor, the load may not be connected. This results in a state in which the motor does not rotate, and a large amount of energy is lost in the form of losses.

FIG. 1 shows the area in which rotational force is applied to the driven body as a load until the driven body begins to rotate as a "balanced portion." For convenience of explanation, the load size of the driven body is assumed to be 5, and it is shown that it is necessary to apply 5 or more power energy to operate the driven body. 1 in the figure is a case where the driving shaft and the driven shaft are directly connected, and the driven body does not operate in the area of the balance portion, resulting in large energy loss. 2 and 3 are cases in which a friction clutch and a fluid clutch are used to transmit power from an electric motor, etc., and sliding friction and sliding hydraulic pressure are generated in the area of the balancing part, respectively.
There is no change in the fact that it is consumed as heat. For example, if the load of the driven object is 5, then 3~
If we add the power energy of 4, then 3~
The motive energy of 4 is simply dissipated as heat. Furthermore, the energy loss due to slip increases depending on the magnitude of load fluctuation and the number of load fluctuations within a certain period of time, and becomes a large value that cannot be ignored as a whole.

An object of the present invention is to provide a power transmission device for a bicycle, etc., which can effectively extract and combine energy lost due to slippage while maintaining the power transmission function as a clutch, and can save energy accordingly.

The present invention rotatably supports both the rotor and stator of a generator, and the rotor (armature)
The shaft of the rotor is connected to a rotational drive source, and a load such as a wheel to be rotated is connected to the stator. Electricity is stored in a storage battery via the storage battery and used by a load device such as a lamp connected to the storage battery.

The invention will be explained below with reference to the illustrated embodiments. FIG. 2 shows the principle of the power transmission device of the present invention, and 10 is a generator. Both the rotor (armature) 11 and the stator field side 12 of the generator are rotatably supported independently, and the rotor (armature) 11 is connected to the electric motor 1 as a drive source, and the stator 12 A driven body (load) 5 to be rotated is connected to. The field coil (not shown) of the stator 12 is connected to the slip ring 1 by an external DC power source DC.
3, the rotor (armature) 11
The armature current is similarly taken out to an external circuit 15 through the slip ring 14. In addition, 18 is the shaft (input side) 16 of the rotor (armature) 11.
19 is a bearing that supports the shaft (output shaft) 17 of the stator 12.

Now, assume that the rotor (armature) 11 is rotated by the electric motor 1 via the input shaft 16. Output shaft 1
Since the load to be rotated is connected to 7, the stator 12 is in a stationary state. Therefore, the rotor (armature) 11 rotates due to the speed difference with respect to the stator (field) 12, and the field is rotated. Cut the magnetic speed φ. The relative speed difference between the rotor (armature) 11 and stator 12 of the generator 10 at this time depends on the magnitude of the load on the output shaft 17. Induced electromotive force is induced in the armature, and this generated power is taken out to the outside through the slip ring 14 and stored in the storage battery 20 in the external circuit 15. On the other hand, at this time, power is transmitted by the interaction between the armature current Ia and the magnetic flux φ. That is, generator 1
The rotation of the stator 12 of 0 increases, and the driven body (load)
As power is transmitted to the generator 10, the relative speed difference (slip difference) between the rotor (armature) 11 and the stator 12 of the generator 10 decreases.

As described above, the generator 10 in this device has both the original function as a generator and the function as a clutch that transmits the power of the electric motor 1 to the output shaft 17. 10 will be referred to as a "power generation clutch."

When transmitting power from a drive source such as an electric motor using a normal fluid clutch or eddy current coupling, if there is slippage between the drive shaft and the driven shaft, the resulting loss is usually lost as heat. However, in the drive device of the present invention, regardless of the magnitude of the slip, even in the area of the balance section in FIG. Since the amount of power corresponding to the amount of power is extracted and stored in the storage battery, such energy loss does not occur. At this time, the power transmission function is not lost.

Now, the rotation speed of the input shaft is n1 [rps], the rotation speed of the output shaft is n2 [rps], and the transmitted torque is T [N-m].
Then, input power P1 = 2πn1T [W] ...(1) Output power P2 = 2πn2T [W] ...(2), and the difference is P1-P2 = 2πn1T (1-n2/n1) [ W] becomes. Here, if slip S=(n1-n2)/n1, it is expressed as P1-P2=2πT・n1S...(3).

On the other hand, the induced electromotive force E'a when the armature and field rotate together is the total number of armature conductors Z, the number of poles P,
Assuming the number of parallel circuits a and the magnetic flux φ [Wb], E'a = pz/aφ (n1 - n2) pz/aφSn1 = SEa [V] ...(2) Load resistance R (including the resistance of the armature circuit) ) is maintained and current Ia flows, the torque is T=Pz/a φ・Ia1/2π =Pz/aφ・SEa/R・1/2π [N-m]...
…(3) becomes. Substituting equations (1) and (2) into equation (3) yields P1-P2=(SEa) ² /R, which is equal to the power consumed by the load resistor R.

In the power transmission device of the present invention, this input/output difference (PIN-POUT) is supplied to the storage battery 20 in the external circuit 15 and is effectively used. For example, if the storage battery 20 is used, a lighting lamp can be turned on using the stored energy.

By the way, the induced electromotive force of a generator depends on the number of poles, magnetic flux, rotation speed, etc., so depending on the purpose of use, the relative speed between the armature and the field may be increased to increase the induced electromotive force. It is preferable.

FIG. 3 shows an embodiment in which a speed increasing gear is used to increase the relative speed between the armature and the field.

In FIG. 3, reference numeral 21 denotes the shaft of the rear wheel of the bicycle, and both ends thereof are attached to the bicycle frame (not shown) via bearings 22, 22. A sprocket gear (not shown) is attached to the shaft 21, and is connected by a chain to a sprocket gear (drive source) that is directly connected to the pedals of the bicycle via a crank sprocket gear. Therefore, when the crank sprocket gear on the pedal side rotates once, the sprocket gear on the rear wheel side, that is, the shaft 21, rotates approximately 2.5 rotations. In this way, the shaft 21 functions as an input shaft.

A cylindrical case 24 is rotatably supported on the shaft 21 via bearings 23, 23, and tires are mounted around the cylindrical case 24 via spokes. The cylindrical case 24 is the shaft 21
It is divided into two parts, a generator room and a speed-up gear room, by a partition wall 25 that is perpendicular to the main compartment. In the generator room located on the left side in FIG. 3, a rotor (armature) 26 is rotatably supported on the shaft 21.
A stator (field) 27 is arranged around it and fixed to the inner wall of the cylindrical case 24. In this case, a gear 2 is provided at the center tip of the rotor (armature) 26.
6a is attached so that it passes through the center of the partition wall 25 and meshes with the large-diameter tooth portion of the gear 36 in the speed-up gear chamber. On the other hand, in the speed increasing gear chamber, a gear 31 is fixed to the right end of the shaft 21, and gears 33, 3 consisting of small diameter teeth and large diameter teeth are mounted on the left side of the shaft 21.
5 are fitted one after another so as to be freely rotatable. In this example, the diameter of the large diameter portion of gears 33 and 35 is
1, and the diameter of the small diameter portion is the same as the diameter of the teeth of the gear 26a of the rotor (armature) 26. Around these gears 31, 33, 35 are two subshafts 2 extending parallel to the shaft 21.
8 is arranged, one end of the shaft is screwed into the partition wall 25, and the other end protrudes from the end surface of the cylindrical case 24 and is screwed into the screw 3.
It is fixed at 0. Idle gears 32, 34, and 36 for increasing speed are rotatably fitted to this subshaft 28, and gear 3 near the input side
1 and the small diameter teeth of the idler gear 32 mesh with each other, and then the large diameter teeth of the idler gear 32 and the small diameter teeth of the idler gear 33 mesh with each other. Similarly, it meshes with the small diameter tooth portion of the idler gear 36. Similarly, the small diameter teeth of the idle gear 36 are engaged with each other in sequence, and finally the large diameter teeth of the idle gear 36 are engaged with the gear portion 26a of the rotor (armature) 26.

Now, if you press the pedal and apply force, shaft 2
1 rotates. Since the tire is in contact with the road surface and is a load, the cylindrical case 24 is initially stationary. The shaft 21 is rotated by gears 31, 32, 3.
3, 34, 35, and 36 and is transmitted to the gear 26a of the rotor (armature) 26, causing the rotor (armature) 26 to rotate at a relatively high speed relative to the stator 27. The rotor (armature) 26 is the stator 2
7, an armature current flows through the rotor (armature) 26 due to electromagnetic induction, and torque is transmitted from the rotor (armature) 26 to the stator 27 due to the interaction between this current and magnetic flux. be done. As the stator 27 begins to rotate, the slip S gradually decreases. The electromotive force generated in the armature depending on the slip S is stored in the storage battery 20. As a result, the cylindrical case 24, that is, the rear wheel, can be rotated by the force of pressing the pedal while generating power according to the load.

A typical bicycle rotates the rear wheel 2.5 times per revolution of the pedal crank, and is directly driven by a chain. However, although the device of this embodiment increases the speed by, for example, changing the gear ratio to about 4 revolutions of the rear wheel per revolution of the petal crank (changing the gear ratio according to the performance of the generator), it does not prevent electromagnetic coupling due to slip rotation. Because it is an indirect drive, the load force felt when using the bicycle by pedaling at a speed of 60 to 70 revolutions per minute is softer than that of a conventional direct drive. Furthermore, as already mentioned, the power transmission efficiency is theoretically the same as that of eddy current couplings, so when riding a bicycle, you do not feel any work or load due to power generation. Therefore, the electrical energy that is constantly stored in the storage battery can be taken out and used at night for the load devices of the headlights, tail lamps, and direction indicators.

The generator functions as a power generation clutch, and the more the clutch slips due to load fluctuations, the more power is generated and stored in the storage battery, and the output torque is adjusted to a value corresponding to the load. Transmit power so that Therefore, the present device consumes less energy during periods of load fluctuation or slippage than conventional clutch-based drive devices, and
It is possible to obtain output torque or speed that corresponds to the size of the load. This effect is remarkable when the device is operated in a place where the load fluctuates rapidly, especially when starting the prime mover. This device also has the effect of softly transmitting the power of a drive source such as a prime mover to the output shaft.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the relationship between the magnitude of the power energy applied to the driven body and the loss of power energy until the driven body acts, and FIG. 2 is a diagram showing the principle of the power transmission device of the present invention. FIG. 3 is a diagram showing an embodiment of the power transmission device of the present invention. 1... Electric motor, 5... Load, 10... Generator,
11, 26...Rotor (armature), 12, 27...
... Stator (field), 13, 14 ... Slip ring, 15 ... External circuit, 16, 21 ... Shaft (input shaft), 20 ... Storage battery, 24 ... Cylindrical case, 31 to 36 ... gear.

Claims (1)

[Claims] 1 Both the rotor and stator of the generator are rotatably supported independently within the case, and the shaft connected to the rotational drive source is connected to the rotor via a speed increasing gear provided within the case, and the stator A load to be rotated is connected to the rotor, and the electromotive force generated in the armature due to the slip between the rotor and stator is stored in a storage battery via a slip ring or rectifier, and used by a load device connected to the storage battery. A power transmission device characterized by: