A device for generating electrical energy

Abstract

The invention relates to a device for generating electrical energy, which device comprises: a base; a pendulum mass, which pendulum mass is mounted on the base for pivoting about a first pivot point and wherein the centre of gravity of the pendulum mass is situated substantially above the pivot point for oscillating in a pendulum range relative to the first pivot point under the influence of external forces, such as for instance ambient vibration forces; - an impact element which extends at least partially in the pendulum range and wherein the pendulum mass is moveable relative to the impact element; and - a triboelectric nanogenerator, coupled mechanically to the impact element for generating electrical energy from an impact of the pendulum mass on the impact element.

Description

[0001] A device for generating electrical energy

[0002] The invention relates to a device for generating electrical energy, which device comprises :

[0003] - a base ;

[0004] - a pendulum mass , which pendulum mass is mounted on the base for pivoting about a first pivot point and wherein the centre of gravity of the pendulum mass is situated substantially above the pivot point for oscillating in a pendulum range relative to the first pivot point under the influence of external forces , such as for instance ambient vibration forces .

[0005] In such an inverted pendulum the pendulum mass is situated above the point of rotation, as seen in the direction of the force of gravity .

[0006] There are known devices which utili ze the principle of an inverted pendulum, as for instance described in NL2015077 and NL2030619 . In the known devices the inverted pendulum is held in a neutral position by means of spring means .

[0007] The spring means for holding the inverted pendulum in a neutral position, these also comprising the triboelectric nanogenerator or piezo generator in the known device , also damp the amplitude of excitations of the pendulum when external forces act thereon .

[0008] It is now an obj ect of the invention to reduce or even wholly obviate the above stated drawback .

[0009] This obj ect is achieved according to the invention with a device according to the preamble , which device is characteri zed in that it also comprises :

[0010] - an impact element which extends at least partially in the pendulum range and wherein the pendulum mass is moveable relative to the impact element ; and - a triboelectric nanogenerator, coupled mechanically to the impact element for generating electrical energy from an impact of the pendulum mass on the impact element .

[0011] Because an inverted pendulum is unstable , it can be moved between di f ferent unstable positions in the pendulum range under the influence of external forces , such as for instance ambient vibration forces or forces generated by means of temperature di f ferences . In the device according to the invention use is made here of an impact element which is situated in the range of the pendulum mass , so that the pendulum mass can come into contact therewith while moving . This results in the pendulum mass striking the impact element with an impulse . Coupling a triboelectric nanogenerator mechanically to the impact element enables electrical energy to be generated from the impulse acting on the impact element . A plurality of impact elements can optionally also be applied .

[0012] Because use is made of a mechanical impulse instead of a gradual compression, as in the known devices , a greater part of the energy exerted by the external force can be converted usefully with the nanogenerator . A better output can hereby be obtained with a device according to the invention than with the known devices . Although the external force is converted into a movement of the pendulum mass in similar manner, owing to the impulse the conversion in the nanogenerator is obtained on the basis of a shorter mechanical action, although an action with a greater amplitude . This appears to produce the observed advantage relative to the existing devices . In order to achieve an impulse on the nanogenerator no compression of the nanogenerator is thus obtained in a part of the pendulum range , this in contrast to the known devices . The spring action of the nanogenerator or additional spring elements can still be utili zed for pendulum characteristic optimi zation .

[0013] In another embodiment of a device according to the invention the nanogenerator is formed by a first material of the impact element and a second material of the pendulum mass , which first and second material form a triboelectric pair .

[0014] A large surface area can hereby be utili zed for generating electrical energy . The mechanical action is here also directly on the nanogenerator .

[0015] Another embodiment of a device according to the invention is an embodiment wherein the nanogenerator is arranged on a contact surface between the pendulum mass and the impact element .

[0016] The nanogenerator can also be arranged on a contact surface between the pendulum mass and the impact element for the purpose of directly absorbing and converting the mechanical impulse . The nanogenerator can here be provided on the pendulum mass and / or on the impact element .

[0017] In yet another embodiment of a device according to the invention the impact element is arranged all around the pendulum mass .

[0018] Arranging the impact element around the pendulum mass enables a movement to result in an impact in any desired direction .

[0019] Another device according to the invention is an embodiment of a device wherein the impact element is pivotable about a second pivot point , which second pivot point lies at a distance from the first pivot point .

[0020] Making the impact element pivotable about a second pivot point enables a large contact surface to be obtained between the pendulum mass and the impact element , also in di f ferent positions of the pendulum mass . Placing the second pivot point at a distance from the first pivot point prevents the impact element from following the movements of the pendulum mass without impact . Owing to the di f ferent pivot points , a collision between the impact element and the pendulum mass is obtained more frequently .

[0021] Yet another embodiment of a device according to the invention is a device wherein the impact element is a tube .

[0022] A tube arranged around the pendulum mass provides large , flat contact surfaces . The pendulum mass preferably has a form corresponding with the impact element and is therefore also tubular in this embodiment .

[0023] Another embodiment of a device according to the invention is a device wherein the impact element is pivotable about a first pivot axis , which first pivot axis cuts the second pivot point and is parallel to a first wall of the impact element .

[0024] Having the impact element pivot about a pivot axis instead of about a pivot point makes it possible to suf fice with a simpler construction . It is particularly with an impulse element enclosing the pendulum mass that a construction with a second pivot point is more di f ficult to reali ze when the second pivot point is situated in the pendulum range .

[0025] In a preferred embodiment of a device according to the invention the impact element is also pivotable about a second pivot axis , which second pivot axis is parallel to a second wall of the impact element lying at right angles to the first wall and preferably cuts the second pivot point .

[0026] The impact element can rotate in the two respective perpendicular planes by means of a second pivot axis placed at right angles to the first pivot axis . When the second pivot axis also cuts the second pivot point here , a rotation about the second pivot point is obtained with combined rotations around the two pivot axes . The impact element is preferably in an indi f ferent equilibrium owing to the pivotable suspension . These and other features of the invention are further elucidated with reference to the accompanying figures .

[0027] Figure 1 shows a schematic representation of an embodiment of the device according to the invention .

[0028] Figure 2 shows a detail of a cross-section of a second embodiment of the device according to the invention .

[0029] Figure 3 shows a detail of a suspension for an impact element according to the invention .

[0030] Figure 1 shows a schematic representation of an embodiment of the device 1 according to the invention . A pendulum mass 3 is arranged on a base 2 . The pendulum mass 3 is pivotable about pivot point 4 . The centre of gravity of the pendulum mass is situated above the pivot point 4 . Provided around pendulum mass 3 is an impact element 5 . The impact element 5 is only shown partially . The pendulum mass 3 is movable relative to the impact element 5 , as indicated with arrow 6 . Arranged on the inner surface 7 of impact element 5 is a triboelectric nanogenerator for generating electrical energy from an impact of pendulum mass 3 on impact element 5 . Impact element 5 is connected by means of a hinge 8 to a housing 9 . The impact element can pivot about the pivot axis 10 . The ef fective mass of pendulum mass 3 can be increased in simple manner by concentrating additional mass at the outer end thereof .

[0031] The nanogenerator can alternatively also be formed on pendulum mass 3 with the material of impact element 5 , such as for instance aluminium, and a second material , such as for instance a polyimide layer such as Kapton®, arranged on the pendulum mass 3 of for instance aluminium . Aluminium and polyimide form a triboelectric pair .

[0032] Figure 2 shows a detail of a cross-section of a second embodiment of a device 11 according to the invention .

[0033] The pendulum mass 13 is arranged on base 12 for pivoting about pivot point 14 . The impact element 15 and the pendulum mass 13 both take the form of a tube . The pendulum mass 13 is movable relative to the impact element 15 , as follows clearly from the applied ball j oint . Arranged on the inner surface 17 of impact element 15 is a triboelectric nanogenerator . The whole is enclosed by a housing 19 to which the impact element 15 is attached .

[0034] Figure 3 shows a detail of a suspension for an impact element 25 according to the invention . The impact element 25 is pivotable about a second pivot point 26 . The pivot point 26 is formed by a rotation about a first pivot axis 27 , which pivoting suspension 28 is in turn attached to a frame 30 pivoting about a second pivot axis 29 . The two pivot axes 27 , 29 are oriented at right angles to each other and are each parallel to a wall of the tubular impact element .

Claims

Claims1 . A device for generating electrical energy, which device comprises :- a base ;- a pendulum mass , which pendulum mass is mounted on the base for pivoting about a first pivot point and wherein the centre of gravity of the pendulum mass is situated substantially above the pivot point for oscillating in a pendulum range relative to the first pivot point under the influence of external forces , such as for instance ambient vibration forces , characteri zed in that the device also comprises :- an impact element which extends at least partially in the pendulum range and wherein the pendulum mass is moveable relative to the impact element ; and- a triboelectric nanogenerator, coupled mechanically to the impact element for generating electrical energy from an impact of the pendulum mass on the impact element .2 . Device according to claim 1 , wherein the nanogenerator is formed by a first material of the impact element and a second material of the pendulum mass , which first and second material form a triboelectric pair .3 . Device according to claim 1 , wherein the nanogenerator is arranged on a contact surface between the pendulum mass and the impact element .4 . Device according to any one of the foregoing claims , wherein the impact element is arranged all around the pendulum mass .5 . Device according to claim 4 , wherein the impact element is pivotable about a second pivot point , which second pivot point lies at a distance from the first pivot point .6 . Device according to claim 4 or 5 , wherein the impact element is a tube .7 . Device according to claim 6 , wherein the impact element is pivotable about a first pivot axis , which first pivot axis cuts the second pivot point and is parallel to a first wall of the impact element .8 . Device according to claim 7 , wherein the impact element is also pivotable about a second pivot axis , which second pivot axis is parallel to a second wall of the impact element lying at right angles to the first wall and preferably cuts the second pivot point .

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