JP5239761B2 - Direct acting generator - Google Patents

Description

  The present invention relates to a direct-acting power generator that is free from a decrease in power generation due to magnetic saturation, has no external leakage of magnetic flux, is small, and has little vibration.

  The driving forces for power generation include thermal power, hydropower, nuclear power, heat, wind power, and tidal power. Conventional generators include a motion conversion mechanism that converts linear motion generated from these driving forces into rotational motion. The conventional power generator has a motion conversion mechanism that increases in size and reduces power generation efficiency due to conversion loss when converting linear motion into rotational motion and friction loss due to mechanical contact.

  In order to solve the above problems, a linear motion generator that converts reciprocating motion, which is one of linear motion, into electric power has been proposed. Since the linear motion generator does not include a motion conversion mechanism, it can be miniaturized, and power generation efficiency is improved because there is no conversion loss or friction loss during motion conversion. Since it is difficult to convert vibration motion into rotational motion with conventional generators, free piston type Stirling engines that generate stroke fluctuation during reciprocating motion, and direct-acting power generation that uses tidal power and vibration power for power generation The machine is expected to be highly efficient.

  As shown in FIG. 4, a conventional linear motion generator 41 includes a substantially cylindrical inner movable yoke 42 and an outer side of the inner movable yoke 42 that is arranged coaxially with the inner movable yoke 42 and can reciprocate in the axial direction. And a substantially cylindrical outer fixed yoke 43 that covers the outer periphery. A permanent magnet 44 with a magnetic pole directed in the radial direction is attached to the center of the inner movable yoke 42 in the axial direction. The outer fixed yoke 43 accommodates a coil 45 wound in the circumferential direction.

  The outer fixed yoke 43 has a gap 46 with a predetermined axial distance located in the axial center of the inner circumference side of the coil 45, and the gap 46 passes from one end of the gap 46 through the inner circumference, outer circumference, and inner circumference of the coil 45. The coil 45 is covered to the opposite end. That is, the outer fixed yoke 43 is located on the inner periphery of the coil 45 and is separated by the gap 46 at one end side inner peripheral wall 47 and the opposite end side inner peripheral wall 48, the outer peripheral wall 49 positioned on the outer periphery of the coil 45, The coil 45 includes one end side end wall 50 and an opposite end side end wall 51 which cover the end portion of the coil 45 and are integrally connected from the inner peripheral walls 47 and 48 to the outer peripheral wall 49.

  The principle of power generation is that when the inner movable yoke 42 moves in the axial direction and the relative position with the outer fixed yoke 43 changes, the magnetic flux density of the magnetic flux crossing the coil 45 changes and an electromotive force is generated.

JP-A-11-262234 JP 2004-88884 A

  The operation of the conventional linear motion generator 41 will be described with reference to FIG.

  FIG. 5B shows a state where the inner movable yoke 42 is located in the middle of the reciprocating motion range of the inner movable yoke 42 (referred to as a neutral position). At this time, a magnetic path by the permanent magnet 44 is formed on the end side opposite to the one end side of the inner movable yoke 42. The magnetic path on the one end side forms a short closed magnetic path that passes through the inner peripheral wall 47 on the one end side of the outer fixed yoke 43, the end wall 50 on the one end side of the outer fixed yoke 43, and the inner movable yoke 42. The opposite end side magnetic path forms a short closed magnetic path passing through the opposite end side inner peripheral wall 48 of the outer fixed yoke 43, the opposite end side end wall 51 of the outer fixed yoke 43, and the inner movable yoke 42. The coil 45 does not cross these closed magnetic paths.

  As shown in FIG. 5A, in a state where the inner movable yoke 42 is positioned above the reciprocating range of the inner movable yoke 42 (referred to as an upper position), one magnetic path by the permanent magnet 44 is fixed outside. A short closed magnetic path is formed that passes through the inner peripheral wall 47 at one end of the yoke 43, the end wall 50 at one end of the outer fixed yoke 43, the space, and the inner movable yoke 42. The coil 45 does not cross this closed magnetic path. The other magnetic path includes one end side inner peripheral wall 47 of the outer fixed yoke 43, one end side end wall 50 of the outer fixed yoke 43, an outer peripheral wall 49 of the outer fixed yoke 43, and an opposite end side wall of the outer fixed yoke 43. 51, a long closed magnetic path passing through the inner movable yoke 42 is formed. This long closed magnetic circuit surrounds the coil 45 in the cross section shown. Therefore, a magnetic flux that intersects the coil 45 is generated.

  As shown in FIG. 5C, in a state where the inner movable yoke 42 is positioned below the reciprocating range of the inner movable yoke 42 (referred to as a lower position), one magnetic path by the permanent magnet 44 is fixed outside. The inner peripheral wall 48 on the opposite end side of the yoke 43, the end wall 51 on the opposite end side of the outer fixed yoke 43, the outer peripheral wall 49 of the outer fixed yoke 43, the end wall 50 on the one end side of the outer fixed yoke 43, and the inner movable yoke 42 are passed. A long closed magnetic circuit is formed. At this time, a magnetic flux crossing the coil 45 is generated, but the direction of the magnetic flux is opposite between the upper position and the lower position. The other magnetic path forms a short closed magnetic path that passes through the opposite inner peripheral wall 48 of the outer fixed yoke 43, the opposite end wall 51 of the outer fixed yoke 43, the space, and the inner movable yoke 42. The coil 45 does not cross this closed magnetic path.

  As described above, when the inner movable yoke 42 reciprocates, the magnetic flux intersecting the coil 45 is alternately generated in the opposite direction, so that a large magnetic flux density fluctuation occurs and power generation is performed.

  However, paying attention to the closed magnetic path that does not participate in power generation, in the upper position, a short closed magnetic path that occurs on one end side of the inner movable yoke 42 causes the outer peripheral wall 49 of the outer fixed yoke 43 from the inner movable yoke 42 that is involved in power generation. And a long closed magnetic circuit that overlaps with the inner peripheral wall 47 on the one end side of the outer fixed yoke 43 (area E1 surrounded by a broken line). Even in the lower position, the short closed magnetic path generated on the opposite end side of the inner movable yoke 42 is a long closed magnetic path that goes around the outer peripheral wall 49 of the outer fixed yoke 43 from the inner movable yoke 42 involved in power generation, and the outer fixed yoke 43. Of the inner peripheral wall 48 on the opposite end side (area E2 surrounded by a broken line). Thus, when a plurality of magnetic paths overlap at the same location, magnetic saturation occurs at that location.

  When magnetic saturation occurs in the inner peripheral walls 47 and 48 of the outer fixed yoke 43 through which the long closed magnetic path involved in power generation passes, the magnetic flux density of the long closed magnetic path involved in the power generation decreases, and the power generation amount is reduced. Decrease.

  Thus, since the conventional linear motion generator 41 has a structure in which a plurality of closed magnetic circuits overlap at the same place, there is a problem that the amount of power generation is reduced due to magnetic saturation.

  Further, in the conventional linear motion generator 41, the axial length of the inner movable yoke 42 is always longer than the axial length of the outer fixed yoke 43. For this reason, the volume of the whole direct acting generator 41 becomes huge.

  Further, since the movable mass composed of the inner movable yoke 42 is large, vibration is generated in the direct acting generator 41.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-described problems, and to provide a direct-acting generator that is small in size and has little vibration, with no reduction in power generation due to magnetic saturation, no external leakage of magnetic flux.

  In order to achieve the above object, the present invention has a coil and a gap having a predetermined axial distance on the inner circumferential side of the coil, from one end of the gap to the opposite end of the gap through the inner and outer circumferences of the coil. An outer fixed yoke that covers the coil, an inner fixed yoke that has a gap of a predetermined distance in the radial direction of the coil with respect to the outer fixed yoke, and that faces the outer fixed yoke across the axial gap; One end side movable yoke having a predetermined length in the direction and reciprocating in the axial direction to move from the inside of the radial gap to one end side of the inner fixed yoke, and the one end side movable yoke in the axial direction An opposite end side movable yoke having a length equal to that of the one end side movable yoke and reciprocating in the axial direction to move from the radial gap to the opposite end side of the inner fixed yoke. The one end side movable yoke and In conjunction with the opposite end movable yoke reciprocates in the radial clearance to both sides of the axial gap, are those having a movable permanent magnet to face the magnetic pole in the radial direction.

  The axial length of the movable permanent magnet may be (the length of the axial gap + the reciprocating distance) / 2.

  The axial length of the inner fixed yoke may be equal to the distance from one end side of the movable permanent magnet to the opposite end side of the opposite end side movable yoke.

  The present invention exhibits the following excellent effects.

  (1) No decrease in power generation due to magnetic saturation.

  (2) The size can be reduced.

  (3) There is little vibration.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, a linear motion generator 1 according to the present invention includes a coil 2 and a gap 3 having a predetermined axial distance on the inner peripheral side of the coil 2. An outer fixed yoke 4 that covers the coil 2 through the outer periphery to the opposite end of the gap 3, and a gap 5 of a predetermined distance in the radial direction of the coil 2 with respect to the outer fixed yoke 4, and extends outside the axial gap 3. An inner fixed yoke 6 facing the fixed yoke 4, one end having a predetermined length in the axial direction, reciprocating in the axial direction, and moving from the inside of the radial gap 5 to one end side of the inner fixed yoke 6. The side movable yoke 7 has the same length as the one end side movable yoke 7 in the axial direction, reciprocates in the axial direction in conjunction with the one end side movable yoke 7, and is opposite to the inner fixed yoke 6 from the radial gap 5. Opposite end side movable yoke 8 that moves to the opposite end side, and one end side movable yoke And the radial gap 5 in conjunction with the opposite end movable yoke 8 reciprocates on both sides of the axial gap 3, and a movable permanent magnet 9 to face the magnetic pole in a radial direction. The linear motion generator 1 is depicted in a posture in which one end is up and the opposite end is down.

  The coil 2 is wound around the central axis C with a predetermined diameter at a right angle to the central axis C of the linear motion generator 1.

  The outer fixed yoke 4 has an axial gap 3 of a predetermined distance located in the axial center of the inner circumference side of the coil 2, and passes through the inner circumference, outer circumference, and inner circumference of the coil 2 from one end of the axial gap 3. The coil 2 is covered up to the opposite end of the axial gap 3. That is, the outer fixed yoke 4 is located on the inner periphery of the coil 2 and is separated by the axial gap 3 at one end side inner peripheral wall 10 and the opposite end side inner peripheral wall 11, and the outer peripheral wall 12 positioned at the outer periphery of the coil 2. And one end side end wall 13 and the opposite end side end wall 14 which cover the end of the coil 2 and are integrally connected from the inner peripheral walls 10, 11 to the outer peripheral wall 12. The outer fixed yoke 4 has a cylindrical shape, and is fixed to a fixed structure on the outer periphery of the outer fixed yoke 4.

  The inner fixed yoke 6 is formed in a cylindrical shape or a columnar shape centered on the central axis C, and has a predetermined length in the axial direction. The outer diameter of the inner fixed yoke 6 is smaller than the inner diameter of the outer fixed yoke 4. By disposing the inner fixed yoke 6 across the axial gap 3, radial gaps 5 are formed on both ends of the axial gap 3. The inner fixed yoke 6 is fixed to a fixed structure at a location not shown. The axial length L of the inner fixed yoke 6 is preferably equal to or approximately equal to the distance b from one end side of the movable permanent magnet 9 to the opposite end side of the opposite end side movable yoke 8.

  The one end side movable yoke 7 and the opposite end side movable yoke 8 are formed in a cylindrical shape having appropriate inner and outer diameters so that they can smoothly reciprocate while facing the inner fixed yoke 6 and the outer fixed yoke 4. ing. The reciprocating distance s shown in the drawing indicates a range in which one end of the one end side movable yoke 7 moves.

The movable permanent magnet 9 is a cylindrical (annular) permanent magnet having an N pole on the outer periphery and an S pole on the inner periphery, and the inner and outer diameters conform to those of the one end side movable yoke 7 and the opposite end side movable yoke 8. The axial length of the movable permanent magnet 9 is
(Length of axial gap 3 a + reciprocating distance s) / 2
Or similar.

  The one end side movable yoke 7, the opposite end side movable yoke 8, and the movable permanent magnet 9 are integrated with a predetermined distance apart by a structure not shown. Thereby, the one end side movable yoke 7, the opposite end side movable yoke 8, and the movable permanent magnet 9 can reciprocate at the same speed in the same direction in conjunction with each other while maintaining the mutual distance.

  Next, the operation of the direct acting generator 1 will be described.

  As shown in FIG. 2B, when one end side movable yoke 7 and the opposite end side movable yoke 8 and the movable permanent magnet 9 are located in the middle of the reciprocating range (neutral position), the one end side movable is movable. The yoke 7 faces the inner peripheral wall 10 on the one end side of the outer fixed yoke 4 and faces the inner fixed yoke 6 partially in close proximity. The opposite end side movable yoke 8 faces close to the opposite end side inner peripheral wall 11 of the outer fixed yoke 4 and also faces the inner fixed yoke 6 partially close. The movable permanent magnet 9 faces the outer fixed yoke 4 partially in the vicinity of the one end side inner peripheral wall 10 and the opposite end side inner peripheral wall 11 across the axial gap 3 and also close to the inner fixed yoke 6. I'm facing.

  At this time, a magnetic path is formed by the movable permanent magnet 9 on the opposite end side to the one end side. The magnetic path on one end side forms a short closed magnetic path that passes through the inner peripheral wall 10 on one end side of the outer fixed yoke 4, the one end movable yoke 7, and the inner fixed yoke 6, and the magnetic path on the opposite end side is the magnetic path of the outer fixed yoke 4. A short closed magnetic path that passes through the opposite end side inner peripheral wall 11, the opposite end side movable yoke 8, and the inner fixed yoke 6 is formed. The coil 2 does not cross these closed magnetic paths.

  As shown in FIG. 2 (a), when the one end side movable yoke 7, the opposite end side movable yoke 8 and the movable permanent magnet 9 are located in the upper part of the reciprocating motion range (upper position), the movable permanent magnet 9 The magnetic path is composed of one end side inner peripheral wall 10, one end side end wall 13, outer peripheral wall 12, opposite end side end wall 14, opposite end side inner peripheral wall 11, opposite end side movable yoke 8, inner fixed side of the outer fixed yoke 4. A long closed magnetic path passing through the yoke 6 is formed.

  On the other hand, since the one end side movable yoke 7 is greatly separated from the inner fixed yoke 6, the air gap is large at that portion (inside the broken line circle), and a closed magnetic path passing through the one end side movable yoke 7 is hardly generated.

  A long closed magnetic path by the movable permanent magnet 9 surrounds the coil 2 in the cross section shown in the figure, so that a magnetic flux crossing the coil 2 is generated and contributes to power generation. This is almost the same as the conventional linear motion generator 41. However, it differs greatly from the conventional linear motion generator 41 in that a closed magnetic circuit that does not participate in power generation does not occur.

  As shown in FIG. 2 (c), when the one end side movable yoke 7, the opposite end side movable yoke 8 and the movable permanent magnet 9 are located at the lower part of the reciprocating motion range (lower position), the movable permanent magnet 9 The magnetic path consists of the opposite end side inner peripheral wall 11, the opposite end side end wall 14, the outer peripheral wall 12, the one end side end wall 13, the one end side inner peripheral wall 10, the one end side movable yoke 7, and the inner fixed yoke. A long closed magnetic circuit passing through 6 is formed.

  Also at this time, unlike the conventional linear motion generator 41, the opposite end side movable yoke 8 is largely separated from the inner fixed yoke 6 (inside the broken line circle), so that the closed magnetic path passing through the opposite end side movable yoke 8 is It hardly occurs.

  As already described, in the conventional linear motion generator 41, the closed magnetic circuit that is not involved in power generation overlaps with the closed magnetic circuit that is involved in power generation at the same location, so that magnetic saturation occurs and power generation is reduced. did. On the other hand, the direct acting generator 1 of the present invention does not generate a closed magnetic circuit that is not involved in power generation. Therefore, magnetic saturation does not occur in the long closed magnetic circuit involved in power generation, and the amount of power generation is increased as compared with the conventional case, so that efficient power generation is possible.

  As described above, according to the present invention, since the closed magnetic circuit that is not involved in power generation is not generated, the magnetic power generation is reduced by avoiding magnetic saturation caused by the overlapping of a plurality of closed magnetic circuits at the same place. Can be prevented. In the linear motion generator 1 according to the present invention, the magnetic flux is switched at almost the theoretical maximum efficiency, and thus the amount of power generation is increased. In the case of the same amount of power generation as that of the conventional linear motion generator 41, the permanent magnet to be used can be reduced.

  Further, since the direct acting generator 1 of the present invention has less magnetic flux leakage than the conventional direct acting generator 41, the magnetic influence on other devices (for example, magnetic sensors) is reduced.

  Moreover, in the conventional linear motion generator 41, since the inner movable yoke 42 including the permanent magnet 44 reciprocates, the movable mass is large. On the other hand, in the linear motion generator 1 of the present invention, the outer fixed yoke 4, the coil 2, and the inner fixed yoke 6, which are heavy, are fixed, and are movable with one end side movable yoke 7 and the opposite end side movable yoke 8. Since the permanent magnet 9 only reciprocates, the movable mass is small. The movable mass in the present invention can be ½ or less of the conventional mass.

  Since the linear motion generator 1 of the present invention has a small movable mass, it can generate electric power with an extremely small driving force as compared with the prior art. Thereby, the direct acting generator 1 whole for obtaining the same generated electric power can be reduced in size compared with the conventional one, and a volume can be made small.

  Since the direct acting generator 1 of the present invention has a small movable mass, the vibration of the direct acting generator 1 can be reduced as compared with the prior art.

  Since the linear motion generator 1 of the present invention has a small movable mass, it is possible to reduce the counter mass to be opposed to the movable mass.

  Unlike the conventional linear motion generator 1 of the present invention, there is no member that protrudes from the outer fixed yoke 4, and a member that reciprocates does not come out of the outer fixed yoke 4. Thereby, the volume of the linear motion generator 1 can be reduced.

  Next, another embodiment of the present invention will be described.

  In the linear motion generator 31 shown in FIG. 3, the inner fixed yoke 6 is fixed to a predetermined axial position by attaching the inner fixed yoke 6 to a spacer 32 having the same inner and outer diameters as the inner fixed yoke 6. The spacer 32 is fixed to a housing (not shown) together with the outer fixed yoke 4 outside the drawing.

  Spacers 33 and 34 are connected between the one end side movable yoke 7 and the movable permanent magnet 9 and between the movable permanent magnet 9 and the opposite end side movable yoke 8. Thereby, the one end side movable yoke 7, the opposite end side movable yoke 8, and the movable permanent magnet 9 can reciprocate in conjunction with each other. Further, here, a movable base 35 is formed in which the inner peripheral portion of the one end side movable yoke 7 is thinly extended to reach the inner periphery of the opposite end side movable yoke 8, and the movable base 35 is opposite to the movable permanent magnet 9. A movable yoke 8 is attached. Even in this case, the one end side movable yoke 7, the opposite end side movable yoke 8 and the movable permanent magnet 9 can reciprocate in conjunction with each other.

  A spiral ring 36 that supports the one end side movable yoke 7, the opposite end side movable yoke 8, and the movable permanent magnet 9 may be provided. Since the spiral ring 36 is free with respect to the housing (not shown), the outer fixed yoke 4 and the inner fixed yoke 6, the spiral ring 36 is driven from the outside of the housing, so that the one end side movable yoke 7 and The opposite end side movable yoke 8 and the movable permanent magnet 9 can reciprocate in conjunction with each other.

  In the embodiments described so far, the N pole of the movable permanent magnet 9 is directed radially outward and the S pole is directed radially inward. However, the S pole is directed radially outward and the N pole is radially inward. You may turn towards.

  Further, in the embodiments so far, the linear motion generator 1 is arranged in such a posture that the reciprocating motion direction of the one end side movable yoke 7, the opposite end side movable yoke 8 and the movable permanent magnet 9 is the vertical direction. The present invention can be applied even when the posture is a direction other than the vertical direction.

It is sectional drawing of the linear motion generator which shows one Embodiment of this invention. 1A is a cross-sectional view at the upper position of the linear motion generator in FIG. 1, FIG. 1B is a cross-sectional view at the neutral position of the direct motion generator in FIG. 1, and FIG. FIG. It is a fracture | rupture solid view of the linear motion generator by other embodiment of this invention. It is sectional drawing of the conventional linear motion generator. 4A is a cross-sectional view at the upper position of the linear motion generator in FIG. 4, FIG. 4B is a cross-sectional view at the neutral position of the direct motion generator in FIG. 4, and FIG. FIG.

Explanation of symbols

1 linear motion generator 2 coil 3 axial gap 4 outer fixed yoke 5 radial gap 6 inner fixed yoke 7 one end side movable yoke 8 opposite end side movable yoke 9 movable permanent magnet

Claims (3)

Coils,
An outer fixed yoke that has a gap of a predetermined axial distance on the inner circumferential side of the coil, covers the coil from one end of the gap to the opposite end of the gap through the inner circumferential outer circumference of the coil;
An inner fixed yoke having a predetermined distance in the radial direction of the coil with respect to the outer fixed yoke and facing the outer fixed yoke across the axial gap;
One end side movable yoke having a predetermined length in the axial direction and reciprocating in the axial direction to move from the inside of the radial gap to one end side of the inner fixed yoke;
It has the same length as the one end side movable yoke in the axial direction, reciprocates in the axial direction in conjunction with the one end side movable yoke, and from the radial gap to the opposite end side than the opposite end of the inner fixed yoke. A movable yoke on the opposite end side that moves,
A movable permanent magnet that reciprocates in the radial gap to both sides of the axial gap in conjunction with the one end side movable yoke and the opposite end side movable yoke, and faces the magnetic pole in the radial direction;
A direct acting generator characterized by comprising:   2. The linear motion generator according to claim 1, wherein the length of the movable permanent magnet in the axial direction is (length of the axial gap + reciprocating distance) / 2.   The linear motion generator according to claim 1, wherein an axial length of the inner fixed yoke is equal to a distance from one end side of the movable permanent magnet to the opposite end side of the opposite end side movable yoke.

Images