FR3138113A1 - Electric bicycle assembly comprising a bicycle frame and a mounting bracket for an electric motor or crankset - Google Patents

Abstract

The present invention relates to an assembly for an electric bicycle comprising a bicycle frame (90) and a mounting bracket (10) for an electric motor (30) or a crankset, characterized in that the mounting bracket (10) is movably mounted sliding on the frame (90) between a first position and a second position in a longitudinal direction (L) of the bicycle and adapted to be selectively fixed to the frame (90) in at least one position between the first and the second position . Figure for abstract: Fig. 2

Description

Electric bicycle assembly comprising a bicycle frame and a mounting bracket for an electric motor or crankset

The invention lies in the field of electric bicycles, in particular in systems for fixing the motor or the crankset to a frame element of an electric bicycle. The invention therefore relates to a support for a bicycle motor or crankset, a frame capable of receiving such a support, and a bicycle comprising the two elements.

State of the art

An electrically assisted bicycle, or electric bicycle, is a bicycle equipped with an auxiliary electric motor and a rechargeable battery. The function of the motor is to provide a complement to pedaling and is typically arranged in the lower part of the frame at the level of the bicycle crankset.

A rear wheel of the bicycle is driven by the engine using a transmission element such as a belt or chain to provide the bicycle with propulsion to move forward. The motor is fixed to the frame in a permanently removable manner, either directly on the frame or via a fixing support such as a lower support arranged at the level of the pedal axle. The bracket is mounted in a predefined position in which the pedals are mounted in a position comfortable for a standard user. However, known mounts for electric bicycle motors do not allow adjustment of the position of the motor and pedals according to the morphology and preferences of the individual user.

In other configurations, the motor is mounted at the hub of the rear wheel, and linked to a crankset via the transmission element.

There illustrates a motor 30 mounted on the frame 90 of a bicycle in a support 10. In a known frame, the motor and its support are fixed relative to the frame. When the transmission element is a belt, adjustment of the belt tension is necessary after assembly to ensure reliable drive without slipping of the belt on the motor or rear wheel.

A disadvantage of the known device is the difficulty of tensioning the belt 60 after mounting the motor 30. Such tension adjustment is carried out by additional parts, for example by sliding rear tabs or a removable tensioner. However, such parts make the assembly of the motor 30 complex and harm the reliability and robustness of the bicycle.

Furthermore, such parts must be precisely adapted to the engine and the transmission mode used, not allowing the engine to be replaced by other models of electric motor. Such a replacement may be interesting when assembling the bicycle in order to offer a wider range of bicycles equipped with different types of engines and different transmission elements. It may also be interesting to be able to replace a bicycle motor with another motor later, for example during a repair.

An aim of the invention is to provide a system for fixing the motor or the crankset in the frame of the bicycle allowing tension adjustment of a transmission system such as a belt after assembly, and in such a way that the mounting bracket is easy to assemble and disassemble.

To this end, the invention proposes an assembly for an electric bicycle comprising a bicycle frame and a fixing support for an electric motor or a crankset, characterized in that the fixing support is mounted movable in sliding on the frame between a first position and a second position in a longitudinal direction of the bicycle and adapted to be selectively fixed to the frame in at least one position between the first and the second position.

Such a sliding fixing support allows both the fixing of the motor or the crankset and the tensioning of a possible transmission belt, thus limiting the number of parts necessary for assembling the bicycle. In the case of chain transmission and derailleur, such a support makes it possible to modify the geometry by positioning the center of the motor at the desired location within the available adjustment range.

Preferably, the fixing support is removable from the bicycle frame.

Advantageously, the frame has oblong holes extending longitudinally and the fixing support is fixed to the frame by screws passing through the oblong holes.

Advantageously, the assembly comprises at least one slide configured for sliding the fixing support on the frame of the bicycle in the longitudinal direction of the bicycle.

Preferably the slide comprises a longitudinal guide groove arranged in a lower portion of the frame and the fixing support has a rail configured to slide in said guide groove.

Advantageously, the interior of the rail is at least partially hollow.

In certain embodiments, the assembly comprises a system for tensioning a transmission element adapted to connect the motor to a rear wheel of the bicycle, said tensioning system being configured to slide the fixing support relative to the frame to adjust the mechanical tension of said transmission element.

Preferably, the tensioning system is a tapping arranged in the fixing support, said tapping comprising a screw extending in the longitudinal direction of the bicycle, said screw being adapted to abut on the bicycle frame so as to to cause the fixing support to slide relative to the frame.

The invention also relates to a method of mounting an electric motor or a crankset on an electric bicycle, comprising the following steps:

• mounting the motor or crankset on a mounting bracket of an assembly as described above, and
• mounting the mounting bracket on the frame so that the mounting bracket is sliding in the longitudinal direction of the bicycle.

The invention also relates to a method of assembling an electric bicycle comprising:

• mounting the motor or crankset on the bicycle according to a method as described above,
• sliding the fixing support into a position for mounting a drive belt of a rear wheel of the bicycle,
• mounting the belt on the motor or crankset and the axle of the rear wheel of the electric bicycle,
• mechanically tensioning said belt by sliding the fixing support from the mounting position towards a tensioning position, and
• fixing the fixing support on the frame in said tensioning position.

The invention also relates to a method of assembling an electric bicycle comprising:

• mounting the motor or crankset on the bicycle according to a method as described above,
• sliding the fixing support into a mounting position of a drive chain of a rear wheel of the bicycle,
• mounting the chain on the motor and a hub at the axle of the rear wheel of the electric bicycle,
• mechanically tensioning said chain by sliding the fixing support from the mounting position towards a tensioning position, and
• fixing the fixing support on the frame in said tensioning position.

The invention also relates to a method of assembling an electric bicycle comprising:

• mounting the motor or crankset on the bicycle according to a method as described above,
• mounting a chain on the motor or crankset, a set of toothed chainrings and a derailleur arranged at the rear wheel,
• adjusting the position of the motor by sliding the mounting bracket, and
• securing the mounting bracket to the frame in the adjusted position.

Brief description of the figures

Other characteristics and advantages of the invention will emerge from the detailed description which follows, with reference to the appended drawings, in which:

There illustrates a motor and transmission element mounted on a bicycle frame.

There is an exploded view of the bicycle frame comprising a motor and a mounting bracket.

There is a perspective view of a mounting bracket mounted on the frame of a bicycle.

There is a perspective view from below of a portion of a bicycle frame according to the invention.

There shows a bicycle engine in a mounting bracket according to the invention and a transmission belt.

Detailed description of embodiments

Description of the frame, mounting bracket and motor assembly

On an electric bicycle having a motor at the pedals, the motor may be mounted on the bicycle frame in a mounting bracket. In the case of an assembly of a frame and a support according to the invention, the fixing support is mounted movable in sliding on the frame before being fixed in a determined position making it possible to ensure mechanical tension and/or an appropriate position of a transmission element connecting the engine to the rear wheel.

In all that follows, the terms “front”, “rear”, “top”, “upper”, “bottom”, “lower” and “side”, are defined in relation to the position of the electric bicycle in a situation of rolling.

There shows an exploded view of a bicycle frame 90, a mounting bracket 10 and a motor for an electric bicycle according to the invention. The lower face of the frame 90 is adapted to receive the fixing support 10.

The mounting support is typically made of a light material that is easy to mold or extrude and machine, for example aluminum. The bracket includes side walls and a rear wall for receiving the motor. The side walls have cutouts or openings to allow access to the motor axle on which the pedals will be attached during complete assembly of the electric bicycle. The support is typically open on its lower face and its front face. The support further comprises retaining tabs for fixing the motor in the support, for example a set of four tabs comprising holes in which the motor can be fixed by screws.

The support may be adapted to a specific bicycle engine or have a generic shape adapted to accommodate different types of engines. In the case where the mounting bracket is specific for one or more engine models, the frame 90 can be adapted to receive several types of mounting brackets. Thus, different types of motors can be used for the same bicycle frame, for example to easily replace a defective motor, to change motors according to a user's wishes, or to offer a wider range of electric bicycles from 'a single model of frame 90.

The motor has an axle that corresponds to the axle of the pedals on the bicycle. The pedals will be fixed at this axis when assembling the bicycle. The engine can be fixed in the mounting bracket before or after mounting the mounting bracket 10 on the frame. The engine can also be removed from the support, for example for a repair, a maintenance operation or for an exchange for another engine model.

The bicycle frame can be a bicycle frame of any type, for example of the city bicycle, mountain bicycle, all-road bicycle or cargo bicycle type. It may include rear legs adapted to the transmission element and the gear change mode. The frame can be made of any material usual for the manufacture of bicycle frames, for example aluminum, steel, or a composite material.

The lower face of the frame may include a structure such as a slide capable of guiding the sliding of a fixing support mounted in the longitudinal direction. Such a slide prevents the support from moving in a lateral or oblique direction during sliding in the longitudinal direction, and thus prevents the engine from shifting on the bicycle. For example, the frame may have one or more guide grooves extending in the longitudinal direction. In this case, the mounting bracket includes one or more longitudinal rails configured to slide within the guide groove(s) of the frame. In a preferred embodiment, with reference to the , the frame 90 comprises a guide groove 15 having a rectangular profile and the fixing support 10 comprises a rectangular guide rail 12. The guide rail 12 can be entirely or partially hollow in order to reduce the quantity of material necessary for the support 10 while maintaining good rigidity of the rail 12. The use of a lesser quantity of base material allows savings to be made for the manufacture of the support 10 and to design a lighter assembly, which is advantageous for the performance and ease of use of the bicycle.

There shows a portion of the frame 90 intended to receive the fixing support 10 from below. A guide groove 15 extends in a longitudinal direction L. The groove 15 is arranged between the oblong holes 25 and partially formed by the edge of said holes and can receive a guide rail arranged centrally on the upper face of a support of fixation. The screws 21 can be moved forward and backward of the bicycle frame inside the oblong holes.

In other embodiments, one or more grooves may be included in the mounting bracket, and one or more guide rails on the underside of the bicycle frame.

The frame includes fixing elements capable of fixing the support on a lower part near the position of the engine. The fixing elements allow adjustment of the position of the support relative to the frame in a longitudinal direction and are typically a plurality of oblong holes capable of receiving fixing screws.

For example, as shown in , the frame 90 may have four oblong holes 25 on the upper face 20 of the support 10 near the four upper corners of the support 10, each receiving a respective fixing screw 21. Conversely, the frame may have circular holes and the fixing support has oblong holes allowing sliding in the longitudinal direction L of the bicycle.

Alternatively (not illustrated), the frame may include two elongated oblong holes arranged on both sides of the upper face of the support and each receiving two respective fixing screws. According to another possibility, such oblong holes and the corresponding screws can be arranged on the sides of the frame and the support. Furthermore, any other holding system allowing sliding in the longitudinal direction of the bicycle can be used, for example holding by clipping.

The entire frame and mounting support may further include a tensioning system to adjust the position of the motor after mounting a transmission element. Such a tensioning system makes it possible to carry out movements of the motor in the longitudinal direction with high precision and against a mechanical resistance which can be exerted by the transmission element during its installation. For example, the tensioning system may comprise a tapping made in the longitudinal direction L in the fixing support from the front face or the rear face. There and the illustrate such a tapping 50 arranged on the front face of the fixing support 10. The frame 90 of the bicycle may include an orifice at the level of the tapping 50 included in the fixing support 10 to allow the passage of a screw 55. Said orifice retains the head of the screw 55 to form a stop, and allows the passage of the portion of the screw 55 carrying the thread. Typically, the tapping and the associated orifice are offset relative to the middle plane of the bicycle perpendicular to the axis of the crankset 35, in order to ensure good accessibility to the tightening screw 55. Furthermore, a lateral offset allows arrange the tapping in a side wall of the fixing support 10 which is a solid and robust part to resist the mechanical forces exerted on the fixing support 10 during tensioning.

In the example illustrated in , the head of the screw abuts the edge of the hole in the bicycle frame at the level of the front opening of the tapping. Alternatively, the thread can pass through the fixing support and the screw can abut with another portion of the frame 90 of the bicycle, for example at the level of the tip of the screw 55.

In other embodiments, the tensioning system may include a cam, a lever arm, or tangent pads.

Such a mounting support can also be used for another means of bicycle training. For example, for an electric bicycle comprising a motor in the hub of the rear wheel, such a mounting support can be used to accommodate a conventional crankset or a crankset comprising a gearbox. In these cases, the driving element can be a belt or a chain.

Typical cases of such use are:

• A motor in the rear wheel hub in combination with a chain or belt. A crankset comprising a gearbox is arranged in the mounting support.
• A motor in the hub of the rear wheel in combination with a chain, a derailleur and sprockets at the rear wheel. A classic crankset is arranged in the mounting bracket.
• A motor in the rear wheel hub in combination with a chain, configured for single speed use. A classic crankset is arranged in the mounting bracket.

In each case, a specific mounting bracket for the crankset can be used. This specific support is compatible with the same frame as the mounting support for an electric motor and can also be mounted movable in sliding.

Assembly

During a first step of mounting the fixing support on the frame, the fixing support is mounted on the frame so that said support is free to slide between a first position in which the support is placed as far as possible towards the front of the frame, and a second position in which the support is placed as far towards the rear of the frame as possible. The sliding takes place only in a longitudinal direction L of the bicycle, which corresponds to the direction of movement of the bicycle and the opposite direction. For example, in the embodiment of the , such an assembly step is typically the maintenance of the fixing support by screws 21 inserted in the oblong holes 25 arranged in the frame 90 or the fixing support 10, allowing the sliding of the support 10 relative to the frame 90. In the embodiment illustrated in , each screw 21 is inserted into the oblong hole in the frame and into an orifice provided for this purpose in the fixing support. In some cases, a thread suitable for the fixing screw is arranged in the fixing support. We then begin to screw each screw into the thread. In other embodiments, the mounting screws pass through a hole in the mounting bracket. In this case, we use nuts that we screw onto the end of each screw.

In other embodiments, the frame includes holes matched to the diameter of each screw and the mounting bracket includes elongated holes. In this case, insert the screws into the holes in the frame and the elongated holes in the mounting bracket, and screw a nut onto the end of each screw.

In each embodiment, the screws are held without tightening them completely to allow the sliding of each screw 21 in the oblong hole 25 and thus allow the sliding of the fixing support 10 relative to the frame 90 of the bicycle.

If the frame and the fixing support include a slide, for example the guide groove and a rail sliding in such a groove, the slide is assembled for example by inserting the rail into the groove during this first assembly step. The slide can now ensure sliding of the support in the longitudinal direction L, avoiding movements in the lateral or oblique direction which could harm the correct adjustment of the motor and the pedals.

The motor can be mounted before or after the step of fixing the support by sliding it onto the frame. After fixing the motor in the support, we will finalize the assembly of the tensioning system, for example insert the screw 55 in the tensioning thread, so that the screw abuts on the bicycle frame 90 and a rotational movement of the screw causes a movement of the fixing support relative to the frame in the longitudinal direction.

We then mount the transmission element at the level of the motor of the rear wheel of the bicycle. Such a transmission element can be a belt or a chain. Typically, during assembly of the transmission element, a mechanical force is exerted on the motor and the mounting bracket which causes sliding of the mounting bracket 10 towards a position at the rear of the bicycle frame. However, the mount can take any position between its maximum front and rear positions.

In the case of a belt transmission, it is necessary to tension said belt after its assembly. We therefore carry out a mechanical tensioning of the belt which is fixed at the level of the engine and at the level of the rear wheel of the bicycle. For this purpose, the tensioning system is used, for example a tensioning screw 55 which is inserted into the orifice 50 provided for this purpose.

After inserting the screw 55 through this hole, with reference to the , screw 55 into the thread. By continuing to tighten the screw 55 in contact with the frame 90 of the bicycle, a movement of the fixing support 10 is caused in the direction of the screw head. The fixing support 10 comprising the motor thus undergoes a movement in the longitudinal direction L towards the front of the bicycle to adjust the tension of the belt.

When the desired tension of the belt is reached, the support 10 is in a position which is between the first position and the second position. In a second step of mounting the fixing support 10, the support 10 is blocked on the frame 90 in a fixed manner in this position obtained during tensioning. The second assembly step is for example by tightening the fixing screws 21. No sliding in the longitudinal direction L is possible after this assembly step.

In the case of a chain transmission, a similar tensioning is carried out if the rear wheel does not have a derailleur. For example, the rear wheel may have an integrated gear hub or a single speed hub. The single-speed hub can be used in combination with an electric motor with a gearbox, or with a motor without the possibility of speed selection.

After mounting the chain in such a configuration, we therefore carry out a mechanical tensioning of the chain which is fixed at the level of the engine and at the level of the rear wheel of the bicycle. As in the embodiment of a belt transmission, the tensioning system is used.

When the desired chain tension is reached, the support 10 is in a position which is between the first position and the second position. The support is fixed on the frame in this position obtained during tensioning. No sliding in the longitudinal direction L is possible after this assembly step.

In the case of transmission by a chain and the use of a hub with a derailleur at the rear wheel, said chain engages with the toothed chainrings and the derailleur of the bicycle. The derailleur is used to adjust the tension of the chain and precise tensioning is not necessary during assembly. In this case, the sliding of the fixing support 10 can be used to adjust the position of the motor and the pedal axle in order to optimize the comfort of the user of the bicycle.

After the first step of mounting the mounting bracket 10 and mounting the motor, the mounting bracket 10 is movable in sliding. We mount the transmission chain on the engine, a set of toothed plates and a derailleur which are arranged at the rear wheel.

Advantageously, the wheels of the bicycle, the handlebars and the saddle are also mounted on the frame 90. In this case, the user can get on the bicycle in order to determine the optimal position of the engine depending on the morphology and its characteristics. wishes. In certain cases, the user knows the desired position of the motor and can communicate this position to a professional, who can proceed with the assembly or personalized adjustment of the bicycle. Once the position of the motor in the fixing support 10 has been adjusted, the second assembly step is carried out so as to block the fixing support 10 on the frame 90 to make it immobile.

This last blocking step is reversible and it is later possible to release the fixing support by sliding in order to modify the position of the motor and adapt it, for example, to another user or another use of the bicycle. For example, different motor positions can be chosen depending on the terrain and/or the speed of the bicycle envisaged.

Furthermore, the mounting support is removable and it is therefore possible to subsequently dismantle the support from the frame, for example in the case of replacing the motor with another motor adapted to a different support.

It is also possible to change the engine and/or the transmission element later, as the support can be adapted to both types of transmission elements.

Consequently, the fixing support allows great versatility of use and adaptation.

Advantageously, the first and second assembly steps can be carried out using a standard tool such as a screwdriver, a screw wrench and/or an Allen key. The support can also be dismantled, locked in its fixed position and unlocked to become sliding in the longitudinal direction by such a tool. This allows a user to adjust the position of the motor independently, without calling a professional.

In the case of using a mounting bracket for a crankset without a motor, the same tensioning advantages can be obtained for the assembly of the chain or the drive belt. In the case of drive by a chain and the presence of a derailleur configured to tension the chain, sliding in the longitudinal direction during the first assembly step can be used to adjust the position of the crankset according to the wishes of the chain. an user.

Claims (12)

Electric bicycle assembly comprising a bicycle frame (90) and a fixing support (10) for an electric motor (30) or a crankset, characterized in that the fixing support (10) is slidably mounted on the frame (90) between a first position and a second position in a longitudinal direction (L) of the bicycle and adapted to be selectively fixed to the frame (90) in at least one position between the first and the second position. Assembly according to claim 1, in which the fixing support (10) is removable from the frame (90) of the bicycle. Assembly according to claim 1 or claim 2, in which the frame has oblong holes (25) extending longitudinally and the fixing support (10) is fixed to the frame (90) by screws (21) passing through the holes oblong (25). Assembly according to any one of the preceding claims, comprising at least one slide configured for sliding the fixing support (10) on the frame (90) of the bicycle in the longitudinal direction (L) of the bicycle. Assembly according to claim 4, in which the slide comprises a longitudinal guide groove arranged in a lower portion of the frame (90) and the fixing support (10) has a rail (12) configured to slide in said guide groove. Assembly according to claim 5, in which the interior of the rail (12) is at least partially hollow. Assembly according to any one of the preceding claims, comprising a system for tensioning a transmission element (60) adapted to connect the motor to a rear wheel of the bicycle, said tensioning system being configured to slide the fixing support (10) relative to the frame (90) to adjust the mechanical tension of said transmission element (60). Assembly according to claim 7 in which the tensioning system is a tapping (50) arranged in the fixing support (10), said tapping comprising a screw (55) extending in the longitudinal direction (L) of the bicycle , said screw (55) being adapted to abut on the bicycle frame (90) so as to cause sliding of the fixing support (10) relative to the frame (90). Method of mounting an electric motor or a crankset on an electric bicycle, comprising the following steps:

• mounting the motor (30) or the crankset on a fixing support (10) of an assembly according to one of the preceding claims, and
• mounting the fixing bracket (10) on the frame (90) so that the fixing bracket (10) is sliding in the longitudinal direction (L) of the bicycle.

Method of assembling an electric bicycle comprising:

• mounting the motor or the crankset on the bicycle according to the method of claim 9,
• sliding the fixing support (10) into a position for mounting a drive belt of a rear wheel of the bicycle,
• mounting the belt (60) on the motor (30) or the crankset and the axle of the rear wheel of the electric bicycle,
• mechanically tensioning said belt (60) by sliding the fixing support (10) from the mounting position towards a tensioning position, and
• fixing the fixing support (10) on the frame in said tensioning position.

Method of assembling an electric bicycle comprising:

• mounting the motor or the crankset on the bicycle according to the method of claim 9,
• sliding the fixing support (10) into a position for mounting a drive chain of a rear wheel of the bicycle,
• mounting the chain on the motor (30) and a hub at the level of the axle of the rear wheel of the electric bicycle,
• mechanically tensioning said chain by sliding the fixing support (10) from the mounting position towards a tensioning position, and
• fixing the fixing support (10) on the frame in said tensioning position.

Method of assembling an electric bicycle comprising:

• mounting the motor or the crankset on the bicycle according to the method of claim 9,
• mounting a chain on the motor or crankset, a set of toothed chainrings and a derailleur arranged at the rear wheel,
• adjusting the position of the motor by sliding the fixing support (10), and
• fixing the mounting bracket (10) to the frame (90) in the adjusted position.