The invention relates to a mechanical frequency con verter.

A geartrain is an example of such a mechanical fre quency converter. Notable disadvantages of the known mechani cal frequency converter are friction between its components, a difficult assembly, and backlash.

The invention is aimed to provide a mechanical fre quency converter in which these disadvantages are alleviated or removed.

The mechanical frequency converter of the invention is embodied with the features of one or more of the appended claims .

First and foremost the mechanical frequency converter of the invention is built in MEMS (wherein MEMS stands for mi croelectromechanical systems) , and comprises an input receiving end for a back-and-forth input motion with a first fre quency and hinged to a frame, and an output receiving end hinged to the frame for a back-and-forth output motion with a second frequency, wherein between the input receiving end and the output receiving end a construction is provided which is embodied with a plurality of hinges, and the input receiving end and the output receiving end are movable substantially in a same plane and arranged such that the output motion of the output receiving end is depending on the input motion of the input receiving end, and the first frequency of motion at the input receiving end is converted to the second frequency of motion at the output receiving end, wherein reversal of the motion direction of the output receiving end occurs when at least one condition is satisfied of the group comprising a first condition wherein three hinges are aligned, and a second condition wherein a first hinge connected to the input receiv ing end and a second hinge connected to the output receiving end are on a same virtual line through the first hinge and the second hinge, wherein said virtual line is then exactly per pendicular to a movement direction of the input receiving end.

The combination of these features covers several em bodiments as will be elucidated hereinafter. The beauty of the mechanical frequency converter of the invention is that it is completely without bearings, is devoid of friction and has very little if any loss of energy.

In one embodiment it is preferred that the directions of motion of the input receiving end and the output receiving end are substantially orthogonal. This is however not essen tial .

In a preferred embodiment the converter comprises a frame, wherein both the input receiving end and the output receiving end are movably connected to the frame with beams. These beams are required to provide the input receiving end and the output receiving end with a suitable ovability that enables their mutual linking and transfer of motion from the input receiving end to the output receiving end.

Suitably the beams provide a hinging connection be tween the frame and the input receiving end and the output re ceiving end, respectively.

According to an embodiment representing a relatively simple design, the construction is embodied with a flexible beam or beams directly connecting the input receiving end and the output receiving end to each other. In this embodiment the construction amplifies the frequency but the output stroke and as result the output speed is low.

According to a an embodiment representing a relative ly more complicated design, the construction amplifies the frequency and also the output stroke which means amplifying the speed and frequency at the same time. This construction is embodied with a rigid central beam with sideways extending arms at extremities of the rigid central beam, wherein rela tive to the rigid central beam and on opposite sides thereof flexible beams are provided between and connecting the side ways extending arms of the rigid central beam, and wherein each flexible beam is entirely positioned on one side of the rigid central beam, and that said construction is integrally suspended between the input receiving end and the output re ceiving end, wherein the input receiving end and the output receiving end connect to the flexible beams on opposite sides of the rigid central beam. This provides an appropriate cou pling of input end and output end wherein the flexible beams provide a hinging functionality with reference to the rigid central beam and its side arms that enables the intended mo tion of the output end at double the frequency of the motion of the input end.

Correspondingly the input receiving end and the out put receiving end that connect to the construction are ar ranged to cause that an input motion at the input receiving end causes tilting of the construction, which tilting of the construction causes an output motion of the output receiving end which is orthogonal to the input motion and at double the frequency of the input motion.

Preferably the input receiving end is equipped with preload beams so as to provide that the input end is statical ly balanced. Accordingly the preload beams act as a source of negative stiffness which can counteract the positive stiffness of the frequency converter, which has the advantage that the potential energy that is stored in the device can thus be kept virtually constant in its subjected working range.

If other multiplication factors are required, it is possible to concatenate the mechanical frequency converter of the invention with one or more other mechanical frequency converters of the invention, to meet a predefined multiplier ra tio between a frequency at an input receiving end of the first mechanical frequency converter and the frequency and an output receiving end of the last mechanical frequency converter in the concatenated series of mechanical frequency converters.

The invention will hereinafter be further elucidated with reference to the drawing of an exemplary embodiment of an apparatus according to the invention that is not limiting as to the appended claims.

In the drawing:

-figure 1 shows a mechanical frequency converter ac cording to first embodiment the invention;

-figure 2 shows a mechanical frequency converter ac cording to second embodiment the invention;

-figure 3 shows a mechanical frequency converter ac cording to a third embodiment of the invention;

-figure 4 shows a mechanical frequency converter according to a fourth embodiment of the invention that corre- sponds with the embodiment of fig. 1, yet completed with stat ic balancing features;

-figure 5 shows a mechanical frequency converter ac cording to a fifth embodiment of the invention that corresponds with the embodiment of fig. 3, yet completed with stat ic balancing features;

-figure 6 shows yet another embodiment of the mechan ical frequency converter of the invention; and

-figure 7 shows a series connection of the device of figure 1 and the device of figure 2 concatenated behind each other .

Whenever in the figures the same reference numerals are applied, these numerals refer to the same or similar parts .

With reference to all figures 1 - 6 reference 1 denotes a mechanical frequency converter according to the inven tion which is embodied in mems technology and comprises an input receiving end 2 for a back-and-forth input motion in the direction of arrows A-A' with a first frequency, and an output receiving end 3 for a corresponding back-and-forth output mo tion in the direction of arrows B-B' with a second frequency. Further between the input receiving end 2 and the output re ceiving end 3 a construction 7 is provided that connects the input receiving end 2 and the output receiving end 3.

As is clear from the direction of arrows A-A' and the direction of arrows B-B' the input receiving end 2 is capable to undergo an input motion and the output receiving end 3 is capable to undergo an output motion, wherein the input motion and the output motion are in different directions, which are preferably orthogonal. This is however not essential. The mo tions can also be oblique with reference to each other, or at least not exactly orthogonal. In the embodiment of figure 6 for instance the input receiving end 2 executes a rotational motion over a part of a circular arc, as will be explained hereinafter. The motions of the input receiving end 2 and the output receiving end 3 are further essentially in the same plane .

The output motion in the direction of arrows B-B' is depending on the input motion in the direction of arrows A-A' and the first frequency of motion at the input receiving end 2 is converted to the second frequency of motion at the output receiving end 3. This is reflected by the arrows B and B' pointing in the same direction in fig. 1 and 3 and represent ing the motion of the output receiving end 3, corresponding to a back-and-forth motion of the input receiving end 2 as de picted by arrows A-A' . Opposed thereto figure 2 shows that the arrows B-B' representing the motion of the output receiving end 3 are pointing in opposite directions when the input re ceiving end 2 moves to the right in direction A-A' . This sym bolizes that the output motion of the output receiving end 3 is depending on the input motion of the input receiving end 2, and that the first frequency of motion at the input receiving end 2 is converted to the second frequency of motion at the output receiving end 3. Reversal of the motion direction of the output receiving end 3 occurs during a complete back-and- forth input motion cycle of the input receiving end 2.

The figures 1 - 6 show that the converter 1 comprises a frame 4 and that both the input receiving end 2 and the out put receiving end 3 are movably connected to the frame 4 with beams 5 and 6, respectively. These beams 5, 6 provide a hing ing connection between the frame 4 on the one part and the in put receiving end 2 and the output receiving end 3 on the oth er part .

Figure 1 depicts a relatively simple design in which the construction 7 is embodied with a flexible beam or beams 13 directly connecting the input receiving end 2 and the out put receiving end 3 to each other. Hinges 16 connect the beams 13 of the construction 7 with the input receiving end 2 and hinges 17 connecting beams 13 of the construction 7 with the output receiving end 3. In this embodiment reversal of the mo tion direction of the output receiving end 3 occurs when a first hinge 16 connected to the input receiving end 2 and a second hinge 17 connected to the output receiving end 3 are on a same virtual line through the first hinge 16 and the second hinge 17, wherein said virtual line is then exactly perpendic ular to a movement direction of the input receiving end 2.

Figure 2 shows an embodiment which is comparable to the embodiment shown in figure 1, the difference being that the beams 5 that connect the input end 2 to the frame 4, and the beams 13 that provide a connection between the input end 2 and the output end 3 are oblique or at an angle. Also in this embodiment hinges 16 and 17 connect the beams 13 of the con struction 7 with the input receiving end 2 and the output re ceiving end 3, respectively. Reversal of the motion direction of the output receiving end 3 occurs when a first hinge 16 connected to the input receiving end 2 and a second hinge 17 connected to the output receiving end 3 are on a same virtual line through the first hinge 16 and the second hinge 17, wherein said virtual line is then exactly perpendicular to a movement direction of the input receiving end 2.

In figure 7 the devices of figure 1 {upper part of figure 7) and figure 2 (lower part of figure 7) are concatenated behind each other, which leads to a tripling of the fre quency from first input receiving end to last output receiving end.

Also figure 4 shows an embodiment which is comparable to the embodiment shown in figure 1, here the difference is that the input end 2 is statically balanced by a preload in the direction of arrows C-C' with the aid of beams 14 connect ing the input end 2 to the frame 4. These beams 14 provide negative stiffness to the input end 2 counteracting the posi tive stiffness of the beams 5, 6 and 13 connected to the input receiving end 2 and output receiving end 3.

In the embodiments of figure 1, 2 and 4 an input mo tion at the input receiving end 2 causes an output motion of the output receiving end 3 which is orthogonal to the input motion at the input receiving end 2 and at double the frequen cy of said input motion.

A more complicated design than the design of figures 1, 2 and 4 is shown in figure 3, wherein the construction 7 is embodied with a rigid central beam 8 with sideways extending arms 9, 10 at extremities of the rigid central beam 8. Rela tive to the rigid central beam 8 and on opposite sides thereof flexible beams 11, 12 are provided between and connecting the sideways extending arms 9, 10 of the rigid central beam 8, wherein each flexible beam 11, 12 is entirely positioned on one side of the rigid central beam 8. This construction 7 is integrally suspended between the input receiving end 2 and the output receiving end 3, wherein the input receiving end 2 and the output receiving end 3 connect to said flexible beams 11, 12 on opposite sides of the rigid central beam 8.

With the input receiving end 2 and the output receiv ing end 3 connected to the construction 7, an input motion at the input receiving end 2 causes tilting of the linking construction 7, which tilting of the linking construction 7 caus es an output motion of the output receiving end 3 which is substantially orthogonal to the input motion at the input re ceiving end 2 and at double the frequency of said input mo tion. This applies to both the embodiment of figure 3 and the embodiment of figure 5 to be discussed hereinafter.

In the embodiment of figure 3 the construction 7 is provided with virtual hinges 18, 19 that provide a connection of the construction 7 with the input receiving end 2 and the output receiving end 3, respectively. Actually, beams 11 pro vides the virtual hinge 18 between the input receiving end 2 and the rigid central beam 8, and beams 12 provides the virtu al hinge 19 between the output receiving end 3 and the rigid central beam 8. In this embodiment reversal of the motion di rection of the output receiving end 3 occurs when a first hinge 18 connecting the construction 7 to the input receiving end 2 and a second hinge 19 connecting the construction 7 to the output receiving end 3 are on a same virtual line through the first hinge 18 and the second hinge 19, wherein said vir tual line is then exactly perpendicular to a movement direc tion of the input receiving end 2.

The embodiment shown in figure 5 compares to the embodiment of figure 3, the only difference being that the input end 2 is statically balanced by a preload in the direction of arrows C-C' with the aid of beams 14 connecting the input end 2 to the frame 4. These beams 14 provide negative stiffness to the input end 2 counteracting the positive stiffness of the remainder of the construction acting on the input receiving end 2.

In figure 6 the beams 5 connect the input receiving end 2 to the frame 4, so as to provide that the input receiv ing end 2 can carry out a rotational motion over a part of a circular arc, with a centre point 20 in the frame 4 acting as a virtual hinge. A construction 7 embodied as a single beam connects the input receiving end 2 to the output receiving end 3, which in turn is connected through flexible beams 6 with the frame 4. The construction 7 connects with hinges 16 and 17 to the input receiving end 2 and the output receiving end 3, respectively. In this way rotational motion of the input re ceiving end 2 over a part of a circular arc with the virtual hinge 20 acting as the centre point causes that the construc tion 7 will drive the output receiving end 3 up and down. Re versal of the motion direction of the output receiving end 3 occurs when the hinges 16, 17 and the virtual hinge 20 are aligned .

Although the invention has been discussed in the foregoing with reference to an exemplary embodiment of the me chanical frequency converter of the invention, the invention is not restricted to this particular embodiment which can be varied in many ways without departing from the invention. The discussed exemplary embodiment shall therefore not be used to construe the appended claims strictly in accordance therewith. On the contrary the embodiment is merely intended to explain the wording of the appended claims without intent to limit the claims to this exemplary embodiment. The scope of protection of the invention shall therefore be construed in accordance with the appended claims only, wherein a possible ambiguity in the wording of the claims shall be resolved using this exem plary embodiment.