WO2008058350A2

WO2008058350A2 - Bicycle crank assembly comprising magnets for force distribution

Info

Publication number: WO2008058350A2
Application number: PCT/BE2007/000119
Authority: WO
Inventors: Johnny Kempenaers
Original assignee: Johnny Kempenaers
Priority date: 2006-11-13
Filing date: 2007-11-12
Publication date: 2008-05-22
Also published as: WO2008058350A3; BE1017364A6

Abstract

A bicycle crank assembly with improved force dispersion by using' magnetic forces wherein a bicycle-crank is added with 2 fixed rings of permanent magnets (1,3) and in between a turning, ring (2.). All rings are changing the radial polarity every 90 degrees resulting in a torque- tension that varies and divides more evenly the energy of the cyclist over the full cycle. The energyis being stored when maximum force can be given by the cyclist and is completely being returned to the crank when less or no power can be given during the dead point cycle. This results in more efficient and enjoyable driving and prevents knee injuries or tendonitis.

Description

A crankshaft constellation with improved force dispersion bv using magnetic forces

The invention involves an improved bicycle crank assembly, an assembly of permanent magnets mounted on the crank will store and release energy from the cyclist and disperse the energy more evenly over the full cycle of the crank without any loss of energy or touching components.

This to eliminate the "dead point" that occurs when conventional pedals are vertically positioned

Solution 1: The crank of the bicycle is added with an assembly holding two irregular magnetic rings of Neodymium (NdFeB) and two fixed neodymiurn magnets positioned on the frame that reach in between the rings to create a magnetic field that varies. Due to the irregularity of the magnetic rings the distance between the turning rings and the fixed magnets varies and so does the power of the magnetic field. The N-pole of the outer ring is opposite the N-poles of the fixed magnets and the S-pofe of inner ring opposite the S-poles of the fixed magnets. This creates a magnetic power field that is stored during the power stroke of the cyclist and slowly released during the dead point.

This results in higher efficiency of energy in all gears and will avoid uphill zigzag movement.

In the following patents DE19942413 en WO9313470, the effect of the dead point is being treated by the use of a mechanical construction using springs and moving components that cause friction and energy loss. In proposed solution there are no touching components allowing 100 % of the stored energy to be dispersed throughout the full cycle.

In the following patents EPQ392Q63, US382621, US2004237708, FR2645825 en

WO9922981 the effect of the dead point is being treated by energy stored in springs that by energy release stilt require counter force of the cyclist. In present solution the stored energy is being released from a fixed point with the frame.

Description:

According to fig 1. The assembly is a round plate (19) mounted on the crank (21) of the pedal with attached two irregular ring-shaped permanent magnets (1,3) as an anker, the rings (2,3) are Neodymium (NDFeB) and they are polarised with the N pole outwards for approximate90 degrees and then they are polarised opposite with the S pole outwards again for approximate90 degrees, and then again opposite (N pole outwards) for approximate 90 degrees and again opposite (S pole outwards) until the cycle is complete.

In between the two rings is a floating third ring (2) attached as a rotor to the crank (21).

This third ring (2) is polarised in approximate the same way as the two fixed rings, therefore in rest position the crank will automatically position itself with the N poles of the two fixed rings (1,3) or anker opposite the S poles of the floating ring (2) in between or rotor and visa versa.

This position Is ideal for the start position of the bicycle since this is the beginning of the power stroke and the end of the "dead point".

During the next 90 degrees, the power stroke of the cycle, part of the energy will be needed (or stored) to turn the rotor ring (2) forward in between the two anker rings

(1,3) since all the N poles are being pulled away from the S poles and being pushed towards the N poles and visa versa.

During the following 90 degrees after the power stroke (the dead point), the stored energy Sn the magnets is completely given back since the S poles now attract the N poles and are being pushed away from the S poles and visa versa.

This way the energy of the cyclist is being divided over the full cycle of the crank.

Since there are no moving or touching components there is now ware and tare or energy loss.

This results in increased efficiency for the cyclist and the driving becomes more enjoyable, especially uphill and with strong headwinds. The torque on the chain wheel is much more continuous and the speed does not drop two times a cycle with energy toss as a result since the cyclist is continuously accelerating to keep a steady speed.

When holding the weight on the pedal in a driving rest position before a corner for example, the energy is being kept in the magnets ready to be used at the restart. As soon as the weight is being hefd from the pedai to start cycling, the bike wiii be pushed into the cycle.

The thickness and/or size of the magnet rings are determined by the energy that is needed to be stored.

The stored energy is also being adjusted in two ways, first the floating ring or rotor is being adjusted with 6 screws (10,11,12,13,14,15) along the axis more or less inside the magnetic field of the two fixed rings (1,3) or anker and second the 90 degree angles of the fixed rings (1,3) are being adjusted away or closer from the rotor ring (2) with 6 screws (4,5,6,7,8,9).

The magnets are being shielded w(th a layer of PVC (22) and behind it metal (23) to enhance their power as well as the housing to minimize external influence.

The construction as presented in (fig. 1) and (fϊg 2.) includes all components and can be mounted as one unit on almost every bicycle. The fixed rings (1,3) or anker are mounted on a round plate (19) that is screwed into the housing of the bicycle spindle and is adjustable with bracket (17) to any bicycle frame (16)

Fig. 1 : A view from the left of the device without cover with view on the 3 rings, anker and rotor.

Fig. 2 : A cut of F|g. 1 along the crank with view of the bracket with attachment to the bicycle

Fig. 3 : A view from the left o the devjce without cover with view on the 3 rings like Fig. After adjustment

Claims

Claims:

1. A crankshaft constellation with improved force dispersion by using magnetic fields whereas the crank is driven by an external force to become a rotary movement in relation to the crank-crankshaft constellation and whereas the magnetic fields generate reaction forces in relation to their angular position which results Fn efther a compensation or either an amplification of the rotational resistance to the driving force, comprising: a series of magnets being integrated in a driven crank- crankshaft constellation, reducing peeks of radial driving forces on the crank during the rotation cycle of the crank.

2. A crank-shaft constellation with improved force dispersion by using magnetic fields as described in claim 1, comprising: the fixed positioning of one set of magnets in relation to the crank-crankshaft constellation, and another set of magnets in a fixed position in relation to the crank.

3. A crank-shaft constellation with improved force dispersion by using magnetic fields as described in claim 2, comprising: changing the timing of the reaction forces in relation tot the rotary position of the crank is accomplished by shifting the radial position of any set of magnets relative to the direction of the external drive force.