1. Field of the Invention
The present invention relates to a power assisting transmission system of a power assisting bike, and more particularly to the power assisting transmission system of a power assisting bike capable of achieving forward and backward transmissions or a back pedaling brake effect by forward and backward pedaling.
2. Description of the Related Art
As disclosed in U.S. Pat. No. 6,595,072 entitled “Sensor of the pedaling force of a power assisting bike”, a transmission system of the power assisting bike comprises one or more pairs of screw gears, wherein the screw gear is driven by a pedaling force to rotate in situ, and the other screw gear is engaged by the opposite screw gear installed on a shaft and driven to move horizontally in an axial direction, and the screw gear has a resilience member installed at an end of the screw gear and the resilience member and the shaft of the screw gear have an annular magnet moved synchronously with the screw gear, and a fixed end disposed opposite to a displacing end of the magnet includes a Hall sensor installed thereon, so that the screw gear of the transmission system can produce a lateral force to detect an axial displacement of the screw gear so as to output a voltage signal to control a motor, and the motor can output motive power to the power assisting bike to achieve the power assisting effect. However, when a crank of the power assisting bike is pedaled in a backward clockwise manually and a transmission shaft rotates clockwise (viewing from the direction from an end A1 to the other end A2 of a first transmission shaft A), a one-way ratchet B is installed between the first transmission shaft A and the first left-handed screw gear C capable of rotating the pair of gears counterclockwise, so that the first transmission shaft A rotates clockwise due t the one-way ratchet B, and the first screw gear C cannot be driven to rotate. Therefore, when a conventional power assisting bike is pedaling in a backward direction manually in an idle pedaling status, a chain gear G1 cannot be driven to rotate, so that the power assisting bike does not have any backward pedaling function and it obviously requires improvements.
In view of the aforementioned drawbacks of the prior art, the inventor of the present invention based on years of experience in the related industry to conduct extensive researches and experiments, and finally invented the present invention to overcome the drawbacks of the prior art.
In view of the aforementioned drawbacks, the inventor of the present invention based on years of experience in the related industry to conduct extensive researches and experiments, and finally invented the present invention.
Therefore, it is a primary objective of the present invention to provide a power assisting transmission system of a power assisting bike capable of achieving forward and backward transmissions or a back pedaling brake effect by forward and backward pedaling.
To achieve the aforementioned objective, the present invention provides a power assisting transmission system of a power assisting bike, comprising: at least two pairs of mutually engaged gear sets, including first and second gear sets, and the first and second gear sets including a gear and a sliding gear respectively, and at least one of the first and second gear sets having a gear set comprised of two screw gears; the gear of the first and second gear sets being fixed onto a first transmission shaft, and both ends of the first transmission shaft being coupled to a pedal crank and driven by a pedaling force, and the gear of the second gear set having a male end of a concave and convex connector disposed on an axial end; the sliding gear of the first and second gear sets being installed on a second transmission shaft and engaged and rotated by the corresponding gears of the first and second gear sets on the second transmission shaft to move axially and horizontally, and having a resilience member installed at an axial end; an axial force pad, sheathed on a side of the gear of the second gear set and disposed at a backward pedaling displacing end of the sliding gear of the first and second gear sets; an annular magnet, sheathed on a side of the sliding gear of the second gear set and displaced synchronously by an external force; a Hall sensor, installed at a pedaling displacement end of the annular magnet for detecting a displacement variation of the annular magnet; a ratchet disc, sheathed on a gear edge of the second gear set, and having a chain gear fixed to an edge, and a female end of a concave and convex connector disposed on an internal side and matched with a male end of the concave and convex connector, such that the ratchet disc is driven to rotate selectively forward and backward by the gear of the second gear set; a driving motor, having a reduction mechanism installed at a front end of an output shaft of the motor and comprised of a plurality of reduction gears, and the last reduction gear is sheathed on an external side of the ratchet disc, so that a principle of producing a lateral force by the gear driven by the transmission system during the forward and backward pedaling detects an axial displacement of the sliding gear to output a voltage signal to control the driving motor to output motive power, so as to achieve forward and backward transmissions or a back pedaling brake effect.
The objectives, technical characteristics, measures, effects and advantages of the present invention will become apparent with the detailed description of preferred embodiment accompanied with the illustration of related drawings as follows.
With reference to
In
In
On the other hand, during the back pedaling, the screw gear C drives the screw sliding gear D to rotate, so that the screw sliding gear D produces a lateral force in the direction towards the right end A2 of the first transmission shaft A. Now, the screw sliding gears D, E displace horizontally towards the right end A2. Since the axial force pad T is installed at the right end A2 of the first transmission shaft A, and a gap is reserved between the axial force pad T and the screw sliding gear E, therefore the gap can be used for controlling the displacement of the screw sliding gears D, E moving towards the right end A2. When the screw sliding gears D, E push the right end A2 to contact with the axial force pad T, such action force will be transmitted back to the first transmission shaft A, and the screw sliding gear E also has an action force of the screw gear F in a direction towards the left end A1, so that the action force of the screw sliding gear E onto the screw gear F is offset by the action force of the axial force pad T of the screw sliding gear E to protect the bearings U installed at both ends of the second transmission shaft L respectively and eliminate the axial pushing force of the second transmission shaft L.
With the aforementioned components, a resilience member L1 is sheathed and installed on the second transmission shaft L, so that the resilience member L1 moves and compresses the left end A1 to deform by the lateral force produced by the rotation of the screw sliding gears D, E during the forward pedaling process, so that the displacement of the screw sliding gears D, E can output a torque at the first transmission shaft A linearly to provide a force to return the screw sliding gears D, E to their original positions.
In the present invention, the annular magnet M1 used for detecting the displacement of the screw sliding gears D, E is installed at an edge of the screw sliding gear E, and a Hall sensor N is installed at an edge opposite to the magnet M1 and fixed to a middle plate W coupled to a gearbox casing V, so that the Hall sensor N can be used for sensing the variation of distance of the magnet M1 to accurately measure a voltage signal that represents the intensity of the force of the pedal cranks H1, H2, and the voltage signal can control the output of motive power of the motor O.
Therefore, the motor O is driven by the gear P at the front of the axis to drive the reduction mechanism comprised of the reduction gears Q1, R1, S1 and further drive the chain gear G1 to achieve the effect of outputting a forward assisting motive power.
When the pedal cranks H1, H2 are not pedaled, the voltage signal has an initial voltage value. When the pedal cranks H1, H2 start pedaling, the voltage signal increases, so that the motor O outputs motive power according to the voltage signal and transmits the motive power to the reduction gear S1. If the external side of the ratchet disc B and the last reduction gear S1 of the reduction mechanism are fixed to each other, the reduction gear S1 can be a one-way ratchet B1 for driving the ratchet disc B to rotate forward in a counterclockwise direction, or a clutch 20 being in a locking status, so that the ratchet disc B and the chain gear G1 can be rotated counterclockwise.
When the pedaling is switched to the backward pedaling, the screw sliding gears D, E displaces towards the right end A2, so that the voltage sensing value returns to the initial value or to a value even below the initial value quickly, and the motor O stops outputting the motive power to the reduction gear S1 immediately, and a fixed slip θ is reserved between the screw gear F and the concave and convex connector Q matched with the ratchet disc B (as shown in
In addition, when the external side of the ratchet disc B and the last reduction gear S1 of the reduction mechanism are fixed and the clutch 20 is situated at the locking status, and the rear wheel K1 and the rear chain disc are rotated in the same direction simultaneously, the voltage sensing value is decreased below the initial value in a backward pedaling, so that the motor O and the reduction gears Q1, R1, S1 are rotated backward, so as to drive the ratchet disc B, the chain gear G1 and the rear wheel K1 to rotate clockwise and move in a backward direction.
In addition, since the reduction mechanism has a clutch 20, the clutch 20 is set to a released status when there is no electric assisting power to disconnect the transmission relation with the reduction mechanism provided that the external side of the ratchet disc B is fixed to the last reduction gear S1 of the reduction mechanism, and the motor O will not be rotated during forward or backward pedaling to reduce the pedaling force.
In summation of the description above, the present invention comprises two pairs of mutually engaged gear sets including first and second gear sets, and each gear set includes a gear and a sliding gear, and the first and second gear sets include a gear set comprised of two screw gears, such as a left-handed screw gear C, a right-handed screw sliding gear D, a left-handed screw sliding gear E and a right-handed screw gear F;
The screw sliding gears D, E of the present invention are right-handed and left-handed respectively for increasing the lateral force of the displacement, so that it only requires one of the sets of screw gears C, D or screw gears E, F to be screw gears, and there is no limitation on the other set of screw gears, and the other set of screw gears can be straight gears or screw gears to achieve the effect of producing a lateral force by the screw gears to detect a pedaling force of the power assisting bike 2.
In summation of the description above, the present invention has one or more of the following advantages and effects:
In summation of the description above, the present invention achieves the expected objectives and effects and complies with the patent application requirements, and thus is duly filed for patent application. While the invention has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims.