Assembly for generating electrical or thermal energy from a brake system Technical field

[0001] In one aspect, the present invention is related to assemblies for generating electrical energy from a brake system in vehicles, in particular two-wheeled vehicles. In another aspect, the present invention is related to assemblies for providing thermal management of a battery in vehicles, in particular two-wheeled vehicles, on the basis of thermal energy captured from a brake system.

Background art

[0002] Currently many bicycles have on-board devices that are battery operated. These are installed in electrically propelled (or assisted) bicycles (e-Bikes herein) as well as traditional rider muscularly propelled bicycles.

[0003] Obviously once the battery is flat it must be replaced or recharged, an operation that must be done with the bicycle at stop (e.g. in a garage, home, or shop).

This is a very inconvenient situation often leading to limitations in the functionality of the bicycle "mid-ride"

[0004] A number of these devices require only low to mid power, with typical examples such as :

• Electronic gear shifting systems

• Electronic mountain bike suspension management systems

· Rider-Performance monitoring, like so-called "power meters"

• GPS, and smart phones

• Lights, in particular led lights for street-riding as well as off-road riding

[0005] For e-bikes, one could use the main engine battery of the bicycle to power at least some of these devices as this "Drive-Battery" is at least an order of magnitude more powerful than required by the above devices. There is also the issue that so-called mid-engine electric bicycles must always keep the engine "freewheeling" when no power is applied, meaning that, contrary to e.g. electric cars, regenerative recharging is currently impossible for these e-bikes.

[0006] Finally, for e-bikes, and more in particular electric-drive mountain bikes, it's often the case they are operated in sub-zero temperatures (E.g. snow riding). It's paramount in this case to keep the main Drive-battery warm, as otherwise its effective capacity to deliver electricity drops dramatically. This is normally achieved by starting with a pre-warmed battery (e.g. stored indoors) and riding while constantly requiring significant power output from the electric engine. In this case the internal resistance of the drive-battery while operating at significant amperage is often enough to keep the battery reasonably warm. However, unfortunately in mountain biking this cannot be always achieved. For example, in the case there is a long down-hill section, there is no requirement for engine output while at same time the battery is exposed to a (much) larger amount of cold air due to increased speed of the bicycle. This means that a drive- battery that started a long downhill section with e.g. capacity remaining 50%, arrives at the bottom of the hill with effective capacity 5%. Once this happens, it is very difficult to- rewarm the battery without a long stop at higher room-temperature.

[0007] Obviously, this is a very important limitation of current technology resulting in limited applicability of e-mountain bikes in sub-zero temperatures.

Summary of the invention

[0008] According to a first aspect of the invention, there is therefore provided an assembly as set out in the appended claims.

[0009] According to a second aspect of the invention, there is provided a vehicle as set out in the appended claims.

Brief description of the figures

[0010] Aspects of the invention will be described below with reference to the Fig. 1 , which represents a schematic cross-section of a brake system on a bicycle wheel.

Description of embodiments

[0011] According to a first aspect of the present invention, there is provided a thermoelectric regenerative power device that can efficiently recover energy from the braking action of modern disk brake while at the same time:

· Create Zero load on the bicycle when not in operation;

• Can be used in any bicycle using modern disk brakes, without any specific frame adaptation;

• Can be used to directly power most low-power systems outlined above, in particular electronic shifting systems and electronically-managed suspensions; · It's low weight;

• Has close to zero maintenance.

[0012] According to a second aspect of the present invention, there is provided a thermal management device that directly uses the thermal energy derived from the braking action in modern disk brakes for providing a thermal management of a battery of a vehicle, in particular the main drive-battery of an e-bike, e.g. to heat or re- heat the battery when operated in low temperatures (e.g. 10°C or less), while also at the same time

• Does not incur any extra consumption from the main drive-battery;

• Keep the battery cold when necessary;

· It's low weight.

[0013] Both aspects are based on a heat-transfer device that is directly coupled physically and thermally to the break-pads, e.g. to the caliper of disk brake system pre-installed in a bicycle or motorbike, or other vehicle, e.g. a leisure vehicle.

[0014] It must be noted that above devices can be coupled to either one or both the front and back wheel disk-brakes, but for conciseness, we will only elaborate in detail the case when it is installed in the back wheel.

[0015] Referring to Fig. 1 , a disk brake 10 is composed of a rotating disk

"Rotor" 1 1 affixed to and configured to rotate integrally with the wheel hub 9, and a brake "Caliper" 12 that is affixed to the bicycle chassis "Frame" 8. The caliper 12 overlaps with a section of the Rotor and comprises a very stiff "chassis" containing:

1 . Brake pads 121 , which overlap with a section of the Rotor 1 1 .

2. An actuating system 122, e.g. comprising actuation pistons, operable to bring the Brake pads 121 in frictional engagement with the rotor, e.g. compress them against the rotor in a "sandwiching" action.

3. The actuating system can further comprise a user interface and drive mechanism, e.g. a piston drive mechanism, which can be hydraulic or mechanical, and which allows to transfer a remote command of the user into the pistons to activate the braking action.

All disk brakes operate by converting forward energy "momentum" directly into thermal energy, which must be immediately dissipated into the atmosphere. Therefore, it is well know that the Brake-pads can heat considerably during operation, and this why they are often made of braking compound directly affixed to a heat-conductive metallic "substrate" 123. It is this substrate 123 that is mechanically pushed by the main pistons of the caliper to compress the braking compound towards the "rotor" 1 1 . The substrate is often enlarged beyond the caliper's chassis to expose it to the air and cool the brake pad more effectively.

[0016] In an aspect of the present invention, a flexible and thermally isolated Heat-transfer Device 13 is thermally coupled to the substrate, for moving heat from Brake-pad's substrate towards the heat transfer device (the Thermo-manager), which is itself also advantageously affixed to the bike frame (or fork). The heat transfer device 13 can be mounted at a remote position from the substrate 123 and thermally coupled thereto, while allowing the Brake-pad to move and operate normally within the brake caliper.

[0017] The Heat-transfer Device can comprise or consist of, for example, a possibly flat lead or cable 131 made of copper or aluminium threads possibly within insulated rubber material (or a similar compound with low heat transfer characteristics). Other flexible and efficient heat transfer devices can also be used such as heat pipes, e.g. containing gases or liquids with high heat transfer characteristics.

[0018] The lead or cable is connected to the brake pad's substrate 123 at one end. The connection advantageously ensures a good thermal contact between the substrate and the lead or cable. At the other end, the lead or cable is connected to a Thermo-Manger device.

[0019] In the first aspect, the Thermo-Manager advantageously comprises:

A) Thermoelectric generator (such a Seebeck generator, or Peltier-effect device), capable to convert differential temperature between its sides into electric energy; B) Optionally, a Heat-radiation Device, such as cooling fins. Alternatively, when this is not present, the bike-frame can be used instead;

C) Optionally, an electronic circuit capable to manage the output voltage of the Thermoelectric generator into a pre-set voltage (either step-down or boosting it up) and amperage range;

D) Optionally, electricity storage means in the form of an "all temperature" capacitor (including electrolytic or "super capacitor" ) or a rechargeable battery of any kind; E) Electric connectivity circuits (physical or inductive) capable to transfer electric power to other devices installed on the bike.

[0020] The Thermo-Manger is arranged so the Heat-transfer Device is in physical and thermal contact with the "hot-side" of the Thermoelectric generator and the Heat-radiation Device is physically and thermally connected to the cold side of the Thermoelectric generator.

[0021] The heat-radiation device can be easily arranged so it is directly exposed to the moving air, which the bicycle is naturally exposed during all operating conditions.

[0022] Therefore, when the bike is operated during braking, the thermoelectric device is advantageously configured to achieve the largest possible electric energy recovery from the brake-pads' heat.

[0023] In the second aspect, the Thermo-Manger can comprise:

A) A device capable of interrupting one or more thermal circuit(s) on demand, such as electric relay connecting & disconnecting a thermal connection (e.g., a copper lead or cable) between a first heat-transfer devices as described above and a second heat transfer device described below, the device referred to as a "Thermo-switch";

B) optionally, electronic circuit managing the Thermo-switch powered by its own energy source, the first embodiment of this invention, or the main drive-battery of an e-bike;

C) optionally, means for the electronic circuit to the determine the current temperature of all components of the Thermo-manger, such thermo-resistances or similar electronic devices.

D) A second Heat-Transfer device, e.g. built in a similar manner to the previously described above, called the Heat-Output circuit,

E) The second heat transfer device can comprise a "Drive-battery Encasing" that is capable of transferring heat from the first Heat-transfer Device to and advantageously from the battery while isolating it from the temperature of the environment. This encasing can be made of e.g. heat-transfer compound surrounding the battery's cells (or pre-existing battery case) within a larger case made of thermal isolation materials (E.g. hard rubber).

F) Optionally, a heat-radiation device, which when not present, is substituted by the frame of the bicycle, referred to as radiator.

[0024] In this embodiment, the Thermo-Manger is arranged such that the first heat-transfer device, the Heat-Output Circuit and the Radiator device are all thermally coupled to the Thermo-switch.

[0025] The Heat Output Circuit can be arranged to be thermally connected on its other extreme to the Drive-battery Encasing.

[0026] Therefore, the Thermo-switch can be operated, advantageously through an electronic circuit, such that:

A) Thermal energy of the brake-pad is transferred to the drive-battery, helping in keeping it warm during cold-operation;

B) Optionally, thermal energy of the brake-pad is dissipated into the atmosphere directly through the heat-radiation device;

C) Optionally, eventual excess heat of the drive-battery can be dissipated into the atmosphere;

D) Optionally, none of the above.

[0027] The thermo-switch is advantageously configured as a three-way switch. [0028] It is possible to combine the first and second aspects, e.g. the thermal energy can be transferred from the first heat transfer device to the second heat transfer device via an electric current, e.g. by providing the thermoelectric generator. The second heat transfer device can comprise electric resistive elements. The thermo-switch can be arranged as a control device operable to switch the electric current from the thermoelectric generator to the second heat transfer device.

[0029] Thereafter, and for both aspects, it's entirely possible to design the

Thermo-Manger device such it fits seamlessly nearby the disk brake such on the "chain stay" or lower leg of the front fork.

[0030] The Thermo-Manager can also include electronic communication- capabilities to coordinate with other systems in the bicycle as well as communicate with the user via. E.g. dedicated displays or a smart phone.

[0031] The Thermo-Manager can also include pumps of any kind to actively drive potential liquid or gaseous content within the heat transfer-device(s) and/or drive- battery encasing.

[0032] Finally, it's obvious that when the disk brake is not operating the system is not generating any added mechanical resistance, and the heat-radiation device can be easily designed to be aerodynamically efficient.

[0033] In both embodiments this results in very advantageous energy regeneration for any modern bicycle.

[0034] Aspects of the invention are not limited for application to bikes, but can be applied to other kinds of vehicles.