JP2005051999A - Stator of rotary electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the stator of the rotary electric machine substantially reducing a product cost while improving assembly workability. <P>SOLUTION: The stator of the rotary electric machine is characterized by providing terminal members 16, 17 electrically connecting a halfway part and a tip end part of the neutral point end part of a coil 12 adjacent to an insulating member 11 and by connecting the coil 12 wound to a magnetic pole teeth 15 to the coil 12 of the other stator unit adjacent respectively with the neutral point end part extended, so as to be connected to each other between the adjacent coils 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a stator of a rotating electrical machine, and more particularly to a technique for improving productivity of a rotating electrical machine, reducing product cost, and reducing weight.

  Conventionally, as a stator used in rotating electrical machines such as electric motors and generators, an annular stator core formed by laminating a plurality of magnetic steel plates, and arranged in the circumferential direction of the stator core with a space therebetween, radially inward A coil wound around each of a plurality of magnetic teeth projecting toward the center via an insulating member, a neutral point bus bar which is a ring-plate-like conductive member connecting the inner peripheral side ends of all the coils, and What has the power collection / distribution bus bar which is three ring-plate-like electroconductive members which connect the outer peripheral side edge part of a coil for every three in the circumferential direction is used (for example, patent document 1).

  As shown in FIG. 7, each power collection / distribution bus bar 30 includes a ring plate-shaped portion 30a, an external connection terminal 30b that protrudes radially outward from the outer periphery thereof and is connected to a power source and other external devices, and an inner periphery thereof. And a coil connection terminal 30c connected to the outer peripheral side end of the coil wound around every three magnetic pole teeth in the circumferential direction. As shown by a chain line P in FIG. 7, each power collection / distribution bus bar 30 is provided with an insulating coating so as to cover the entire surface of the ring plate-like portion 30a. The external connection terminal 30b and the coil connection terminal 30c are: It is exposed from the painted surface without any insulation coating.

  As shown in FIG. 8, the insulating member 33 provided in each of the plurality of stator cores 31 is provided with an extending portion 33 a extending outward in the radial direction on the end surface of the stator core 31, and the magnetic poles are interposed via the insulating member 33. A terminal member 34 for fixing one end 32a of the coil 32 wound around the tooth 31a to the extension portion 33a via one connection portion 34a is attached. The terminal member 34 is provided with another connecting portion 34b, and as shown by a chain line in FIG. 8, the coil connecting terminal 30c protruding inward in the radial direction from the inner periphery of the power collection / distribution bus bar 30 is fixed. Can be done. Thereby, when used for an electric motor, the power supplied from the power source is transmitted to the power collection / distribution bus bar 30 via the external connection terminal 30b, and is further fixed to the extension portion 33a of the insulating member 33. It is transmitted to the coil 32 through 34.

Further, the neutral point bus bar 35 protrudes radially outward at a pitch equal to the arrangement pitch of the magnetic pole teeth 31 a of the stator core 31 on the outer periphery, and is connected to the inner peripheral side end portions 32 b of all the coils 32. A point connection terminal 35a is provided. Further, as shown in FIGS. 8 and 9, the insulating member 33 of each magnetic pole tooth 31 includes an extending portion 33 b extending inward in the radial direction on the end surface of the stator core 31, and the other end 32 b of the coil 32 is connected. A terminal member 36 that is fixed to the extending portion 33b of the insulating member 33 is attached via one connecting portion 36a. The terminal member 36 is provided with another connecting portion 36b so that the neutral point connecting terminal 35a projecting radially outward from the outer periphery of the neutral point bus bar 35 can be fixed. . As a result, the neutral point bus bar 35 is configured to connect the inner peripheral side end portions 32b of all the coils 32 to each other to constitute a neutral point of all the coils 32.
JP 2001-25187 A

However, the conventional stator 37 configured as described above has the following problems.
First, the three power collection / distribution bus bars 30 cannot share components due to the phase relationship between the external connection terminals 30b and the coil connection terminals 30c, and it is necessary to use different components for each phase. is there. That is, the external connection terminals 30b provided on the three power collection / distribution bus bars 30 are preferably arranged close to each other for convenience of connection wiring with an external device, but the coil connection terminals 30c are arranged on the magnetic pole teeth 31. Since they are arranged at a pitch three times the arrangement pitch, it is difficult to make them common.

  Further, since the neutral point bus bar 35 is different in structure from the power collection / distribution bus bar 30, it cannot be shared with the power collection / distribution bus bar 30. Therefore, the number of parts is inevitably increased, and there is a problem that a great number of work steps are required for assembly. In particular, since the three types of power collection / distribution bus bars 30 are similar in form, it is difficult to discriminate them when they are mixed, and there is a problem that workability during assembly is reduced.

  Secondly, the three types of power collection / distribution bus bars 30 need to be electrically insulated from each other and to the coils 32 that are not connected to each other. Conventionally, these power collection / distribution bus bars 30 are assembled as separate parts. In the stator 37, there is a problem in that it is necessary to separately perform reliable insulation treatment on all the power collection / distribution bus bars 30. That is, in the conventional stator 37 that performs the insulation treatment for each part individually, a lot of man-hours are required for manufacturing a single part, and in order to obtain a stable insulation performance for each part, a multilayer coating or the like is required. It is necessary to form a uniform insulating coating film by a complicated manufacturing process. Therefore, there is a disadvantage that the product cost increases.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a stator for a rotating electrical machine that can improve assembly workability and can significantly reduce product cost.

In order to achieve the above object, the present invention proposes the following means.
According to a first aspect of the present invention, there is provided a stator core having a plurality of magnetic teeth arranged in the circumferential direction and spaced apart by a predetermined distance, and a plurality of coils wound around the magnetic teeth of the stator core via insulating members. Each coil is a stator of a rotating electrical machine in which a terminal end extending toward one end of the stator unit is extended, and each coil terminal is connected to a coil connection terminal of a conductive member. A terminal member for electrically connecting the midway terminal portion and the tip portion of the midpoint terminal portion is provided, and the coils wound around the magnetic teeth respectively extend the midpoint terminal portion and connect to coils of other adjacent stator units. Thus, a stator for a rotating electrical machine in which adjacent coils are connected to each other has been proposed.

  According to the present invention, the current collecting and distributing end portion of the coil is disposed on one end surface side in the thickness direction of the stator core, and the current collecting and distributing ring is disposed on the end surface to connect the current collecting and distributing end portion and the coil connection terminal. Therefore, it is possible to simply connect the power collection and distribution ring and the coil, and to configure the connection portion in a compact manner. In addition, since a plurality of conductive members are integrated with resin, it is not necessary to perform expensive insulation processing, positioning and fixing for each conductive member, and it is possible to provide an inexpensive stator.

  Since the neutral point end provided on the other end of the coil is directly connected to the vicinity of the neutral point end of the coil extending from the adjacent magnetic teeth, the conventionally used neutral point bus bar is unnecessary, It is possible to provide a stator having a significantly reduced weight.

Near the neutral point end of the coil via the terminal member attached to the insulating member and the neutral point end of the coil extending from the adjacent magnetic pole teeth, both coils can be connected securely and the coil It is possible to maintain the soundness of the connecting portion by fixing the connecting portion to the insulating member and also by the vibration of the rotating electrical machine.

The invention according to claim 2 proposes a stator for a rotating electrical machine in which the stator according to claim 1 has a guide portion for guiding a terminal end portion of a coil adjacent to a terminal member.
According to the present invention, it is possible to easily perform the handling work when the neutral point end of the coil is connected to the terminal member of the adjacent magnetic teeth.

  According to the stator of the first aspect of the present invention, it is possible to reduce the weight of the motor without using a neutral point bus bar. Further, it is possible to provide a low-priced motor by reducing the man-hours and product costs required for manufacturing the neutral point bus bar.

  In addition, since the neutral point terminal of one magnetic pole tooth and the coil extending from the other magnetic pole tooth are connected by the terminal member and fixed to the insulating member, the connection portion is sound even against vibration caused by the operation of the rotating electrical machine. This produces an effect of maintaining a state and providing a highly reliable rotating electrical machine.

  According to the stator of the second aspect of the present invention, since the guide portion can easily perform the handling operation when connecting the neutral point end of the coil to the terminal member of the adjacent magnetic teeth, the assembly workability As a result, it is possible to provide a stator with high productivity.

Hereinafter, a power collection and distribution ring and a stator having the same according to a first embodiment of the present invention will be described with reference to the accompanying drawings.
A power collection and distribution ring 1 according to the present embodiment is a power collection and distribution ring 1 used in a three-phase rotating electrical machine, and as shown in FIG. 1, a strip-shaped conductive plate material is curled (round bent). ) Three bus bars (conductive members) 2, 3, 4 formed in a substantially cylindrical shape and an insulating resin that wraps and fixes the bus bars 2, 3, 4 together And 5.
The power collection / distribution ring 1 is used for power distribution from a power source disposed outside when the rotating electrical machine is an electric motor, and any device disposed outside when the rotating electrical machine is a generator. It is used for collecting electricity.

  Each of the bus bars 2, 3, and 4 has an incomplete cylindrical tubular portion 2a, 3a, 4a lacking a part in the circumferential direction, and a predetermined interval in the circumferential direction between the tubular portions 2a, 3a, 4a. It has a plurality of coil connection terminals 2b, 3b, 4b that are spaced apart and extend radially inward, and external connection terminals 2c, 3c, 4c that extend radially outward from one place in the circumferential direction. The cylindrical portions 2a, 3a, 4a have different radial dimensions in the three bus bars 2, 3, 4, and when arranged in the center, as shown in FIG. It is arranged concentrically with a gap.

  The interval between the coil connection terminals 2b, 3b, 4b is three times the interval between the magnetic pole teeth 7 of the stator 6 described later. Further, as shown in FIG. 1, the lengths of the coil connection terminals 2b, 3b, 4b are equal to the positions in the radial direction in the state where the three bus bars 2, 3, 4 are concentrically arranged. The bus bar 2 having a large radial dimension is long, and the small bus bars 3 and 4 are successively shorter than the bus bar 2 so as to extend to the distance.

  The external connection terminals 2c, 3c and 4c are connected to the coils of the three bus bars 2, 3 and 4 when the ones provided on the three bus bars 2, 3 and 4 are adjacent to each other with a predetermined interval. The terminals 2b, 3b, 4b are provided at predetermined positions on the cylindrical portions 2a, 3a, 4a so that the arrangement pitch of the terminals 2b, 3b, 4b is equal to the pitch of the magnetic teeth 7 protruding radially inward of the stator 6.

  For example, the bus bars 2, 3, and 4 are each punched out from a single metal thin plate, and then curled to form the whole into a cylindrical shape. Thereafter, the coil connection terminals 2b are formed by bending. , 3b, 4b are bent inward in the radial direction, and the external connection terminals 2c, 3c, 4c are bent outward in the radial direction.

As shown in FIG. 1, these bus bars 2, 3, and 4 are integrated with the resin portion 5 in advance in a state where they are concentrically spaced apart from each other before the stator is assembled as shown by a chain line. An integrated conductive unit fixed to is formed.
In order to fix the three bus bars 2, 3, and 4 by the resin portion 5, first, as shown in FIG. 2, the three bus bars 2, 3, 4 are connected to the three grooves 8 a, 8 b, Housed in 8c.

  At this time, the coil connection terminals 2b, 3b, and 4b extending radially inward from the bus bars 2, 3, and 4 are arranged with a phase shifted by an angle equal to the arrangement pitch of the magnetic pole teeth 7, thereby three bus bars. The coil connection terminals 2 b, 3 b, 4 b of 2, 3 and 4 are arranged so as to protrude alternately inward in the radial direction at a pitch equal to the arrangement pitch of the magnetic pole teeth 7. At this time, the external connection terminals 2c, 3c, and 4c of the three bus bars 2, 3, and 4 are arranged adjacent to each other with a predetermined distance therebetween.

  The rail 8 is made of an insulating material, and in order to secure stable insulating performance, the bus bars 2, 3, and 4 are partitioned by sufficiently high side walls so as to obtain a creepage distance. Next, in the state where the three bus bars 2, 3, 4 are accommodated in the grooves 8a, 8b, 8c of the rail 8, the insulating resin is accommodated in a cavity of a mold (not shown) and melted in the cavity. Is injected and cured to form the resin portion 5.

  Thereby, the power collection and distribution ring 1 in which the three bus bars 2, 3 and 4 are integrally fixed by the resin portion 5 is manufactured. In the power distribution ring 1, three bus bars 2, 3, and 4 are integrally formed in an annular resin portion 5 in a state where they are electrically insulated from each other by an insulating rail 8 and an insulating resin. So that the coil connection terminals 2b, 3b, 4b extending from the bus bars 2, 3, 4 extend radially inward and the external connection terminals 2c, 3c, 4c extend radially outward, respectively. It is exposed from the surface of the resin part 5.

  According to the power collection / distribution ring 1 configured as described above, unlike the conventional ring plate-like bus bar 30 (see FIG. 7), most of it is curled from a strip-like conductive plate material (usually a copper plate). Since each bus bar 2, 3, and 4 can be comprised, the yield of an expensive material can be improved and the cost can be reduced significantly.

  Further, the bus bars 2, 3 and 4 do not need to be configured in a perfect cylindrical shape as described above, and the cylindrical portions 2a, 3a and 4a corresponding to approximately three times the arrangement pitch of the magnetic teeth 7 are unnecessary. Material can be saved also in terms of points. Further, when the bus bars 2, 3, 4 themselves are configured in an incomplete cylindrical shape, the strength of the bus bars 2, 3, 4 is reduced. Is supported by the rail 8 and is fixed integrally by being wrapped by the resin portion 5, so that it is not deformed.

  Furthermore, according to the power collection and distribution ring 1 configured as described above, since the three bus bars 2, 3, and 4 are integrated by the resin portion 5, workability when the stator 6 is assembled can be improved. That is, in the conventional method in which the bus bars are separated, it is necessary to mount the three bus bars 30 separately, and in this case, it is necessary to distinguish between three types of bus bars 30 having similar forms. According to the power collection and distribution ring 1 in the form, the three bus bars 2, 3, and 4 can be attached together by a single mounting operation.

  In addition, according to the power collection and distribution ring 1 according to the present embodiment, stable electrical insulation between the three bus bars 2, 3, and 4 can be achieved. In other words, in the conventional method in which the bus bars 30 are separated, it is necessary to separately insulate each of the three bus bars 30, which is troublesome and relatively expensive. On the other hand, according to the power collection and distribution ring 1 of the present embodiment, the bus bars 2, 3, 4 are substantially insulated by the rail 8, and further reliably insulated by the resin portion 5 made of an insulating resin. Since it can be fixed, stable insulation performance can be achieved and the manufacturing cost can be reduced.

Next, the stator 6 of the rotating electrical machine according to the present embodiment equipped with the power collection and distribution ring 1 configured as described above will be described below with reference to the drawings.
As shown in FIG. 3, the stator 6 according to the present embodiment is common to the conventional stator 37 in that it is configured in an annular shape by arranging a plurality of stator units 9 in the circumferential direction. As shown in FIG. 5, the stator unit 9 includes a core unit 10, an insulating member 11, and a coil 12. The core unit 10 comprises a laminated iron core in which a substantially T-shaped magnetic steel plate composed of a back yoke on the outer periphery side of the stator core and magnetic pole teeth protruding toward the inner periphery side of the stator core is laminated. An annular stator core 13 is configured by arranging a plurality of them.

  Further, the stator unit 9 of the present embodiment also has a coil 12 wound around the outer periphery of the core unit 10 constituting the magnetic pole teeth 15 by laminating a plurality of magnetic steel plates 14 as in the conventional case. In the point which is comprised, it is common with the conventional one.

However, the stator 6 according to the present embodiment uses the current collection and distribution ring 1 in which the above-described three bus bars 2, 3, and 4 are integrally fixed by the resin portion 5, and uses the neutral point bus bar 35. This is different from the conventional stator 37 in that it is not.
Also in the stator 6 according to the present embodiment, the terminal members 16 and 17 for connecting the end portions of the coils 12 to the insulating member 11 disposed on the one end surface side in the stacking direction of the magnetic steel plates 14 are on the outer peripheral side of the stator core 13. And it is being fixed to the inner peripheral side by the fixing pieces 16c and 17c, respectively.

  Each terminal member 16, 17 has two connecting portions 16 a, 16 b; 17 a, 17 b formed so as to sandwich the conductor inside, and the terminal member 16 on the outer peripheral side has a magnetic pole tooth 15. One end 12a (power collection / distribution end) of the coil 12 wound around the coil 12 extends to one end surface side in the stacking direction of the laminated steel plates 14 constituting the magnetic pole teeth 15, and is accommodated in one connecting portion 16a. They are electrically connected by any joining method such as crimping, welding or fusing.

  Further, in the other connection portion 16b of the terminal member 16 on the outer peripheral side, as shown by a chain line in FIG. 3, when the above-described current collection and distribution ring 1 is disposed near the outer periphery on the one end face side of the magnetic pole teeth 15, The coil connection terminals 2b, 3b, 4b exposed from the inner periphery of the power collection and distribution ring 1 in the radial direction are accommodated. The terminal member 16 has the same shape at the same position of all the stator units 9.

Thereby, all the coil connection terminals 2b, 3b, 4b protruding from the inner periphery of the power collection and distribution ring 1 with a certain interval in the circumferential direction can be simultaneously accommodated in the connection portion 16b of the terminal member 16. The coils 12 of the three magnetic teeth 15 adjacent in the circumferential direction of the stator 6 can be separated from each other only by electrically joining the coil connection terminals 2b, 3b, 4b and the connection portion 16b. 3 and 4 can be connected.
The vicinity of the connection portion 16b between the coil connection terminals 2b, 3b, 4b and the terminal member 16 is preferably covered with an insulating resin such as a silicone resin to enhance the waterproofness.

Also, the inner peripheral side terminal member 17 has the same structure as the outer peripheral side terminal member 16 described above, but the other end 12b of the coil 12 wound around each magnetic pole tooth 15 has other adjacent ones. A substantially U-shaped neutral point end portion 12c is provided so as to extend to one end face side in the thickness direction of the stator core of the magnetic pole teeth. Then, as shown in FIG. 5, a midway portion 12 e of the neutral point end portion 12 c of the coil 12 wound around each magnetic pole tooth 15 is connected to one connection portion 17 a of the terminal member 17.
Further, as shown in FIG. 4, the other connecting portion 17 b is connected to a tip end portion 12 d of a neutral point end portion 12 c extending from another stator unit 9 adjacent to the other side of the stator unit 9. ing.

That is, according to the stator 6 according to the present embodiment, the neutral point end portion 12c of the coil 12 wound around each magnetic pole tooth 15 is connected to a single neutral point bus bar 35 (see FIG. 8). Unlike the stator 37, the neutral point end 12b of the coil 12 of one stator unit 9 is connected to the neutral point end 12b of the coil 12 of the other adjacent stator unit 9, and the terminal member 17 is connected to the intermediate portion 12e of the neutral point end 12b of the other stator unit 9. Therefore, the neutral point bus bar 35 is unnecessary.
As a result, it is possible to reduce the weight substantially corresponding to the neutral point bus bar 35 and to reduce the product cost of the stator 6.

Next, a stator 20 according to a second embodiment of the present invention will be described below with reference to FIG.
In the description of the present embodiment, portions having the same configuration as that of the stator 6 according to the first embodiment are denoted by the same reference numerals and the description will be simplified.

  As shown in FIG. 6, the stator 20 according to the present embodiment is configured such that the stator units 21 are connected to each other and bendable, the shape of the end of the neutral point, and the insulation of each stator unit 21. The structure of the terminal member 22 on the inner peripheral side attached to the member 11 is different from the stator 6 according to the first embodiment.

  The stator unit 21 of the present embodiment is configured by winding a coil 12 on a core unit 24 connected to each other by a hinge portion 23 formed at a corner portion, after covering a cylindrical insulating member 11. Yes. As a result, when the stator units 21 are bent and moved from the state separated from each other as shown on the left side of FIG. 6 to the position where they are in contact with each other as shown on the right side of FIG. The stator 20 is configured. The neutral point end portion 12b has the other end of the coil formed in a substantially L shape so as to extend and be disposed on one end surface side in the thickness direction of the stator core of another adjacent magnetic pole tooth 15.

  The terminal member 22 includes a first connecting portion 22a connected to the midway portion 12e of the neutral point end portion 12b of the coil 12 of the stator unit 21 to which the terminal member 22 is attached, and the adjacent stator unit 21 side. A second connecting portion 22b connected to the tip end portion 12d of the neutral point end portion 12b of the extended coil 12, and guides the connection of the neutral point end portion 12b to the second connecting portion 22b. And a guide portion 22c.

  The first connecting portion 22a is the same as the connecting portion 17a of the stator 9 according to the first embodiment described above, but the second connecting portion 22b is substantially orthogonal to the first connecting portion 22a. The guide portion 22c is arranged in alignment with the inlet side of the second connection portion 22b. For example, as shown in FIG. 6, the guide portion 22c has a width that gradually decreases toward the second connecting portion 22b. It is directed in the direction of the unit 21.

  According to the stator 9 according to the present embodiment configured as described above, each magnetic pole tooth 15 is covered with the insulating member 11 and the coil 12 is wound around the insulating member 11 as described above. Each stator unit 21 is bent by a hinge portion 23 to form an annular stator 9. At that time, the neutral point end portion 12 b extending from the inner peripheral side of one stator unit 21 is inserted and arranged on the opening 22 d side of the guide portion 22 c of another adjacent stator unit 21 and then moved. Thereby, the neutral point end part 12b is guided in the 2nd connection part 22b along the inner wall of the guide part 22c.

  And when both stator units 21 and 21 contact | abut, the 2nd connection part 22b and the neutral point end part 12b of the coil 12 are joined by arbitrary joining methods, such as crimping | compression-bonding, welding, or fusing. As a result, the vicinity of the neutral point end 12 b of the coil 12 of one stator unit 21 and the neutral point end 12 b of the coil 12 of another adjacent stator unit 21 are electrically connected via the terminal member 22. Is done. By performing this operation on all the stator units 21, the annular stator 9 is configured, and all the neutral point end portions 12b are connected.

  That is, according to the stator 9 according to the present embodiment, the neutral point end portion 12b is guided by the guide portion 22c provided in the terminal member 22 so as to be disposed at the second connection portion 22b. Work can be facilitated.

  In the above description, the stators 6 and 20 for a rotating electrical machine having a plurality of magnetic teeth 15 projecting inward in the radial direction and having rotors (not shown) opposed to each other with a gap therebetween are arranged. Explained with an example. However, the present invention is not limited to the above-described configuration. A stator for a rotating electrical machine in which a plurality of magnetic pole teeth 15 are arranged radially outward and a cylindrical hollow rotor (not shown) is arranged on the outside thereof. Can also be applied.

It is a front view which omits the resin part and shows the power collection and distribution ring concerning one embodiment of the present invention. It is a longitudinal cross-sectional view which shows partially the power collection and distribution ring of FIG. It is a front view which shows the stator of the rotary electric machine which concerns on one Embodiment of this invention. It is an enlarged view of the A section of FIG. It is a front view which shows one stator unit which comprises the stator of FIG. It is a front view which shows partially the stator of the rotary electric machine which concerns on other embodiment of this invention. It is a front view which shows the conventional power collection / distribution bus-bar. It is a front view which shows the stator of the conventional rotary electric machine which shows a single power collection / distribution bus-bar with a dashed line. It is an enlarged view of the B section of FIG.

Explanation of symbols

2,3,4 bus bar (conductive member)
2a, 3a, 4a Coil connection terminal 6, 20 Stator 11 Insulating member 12 Coil 12a Current collection and distribution end (termination)
12b Neutral point end (middle point terminal)
13 Stator core 15 Magnetic teeth 16, 17, 22 Terminal member 22c Guide portion

Claims (2)

  A stator core having a plurality of magnetic teeth arranged in the circumferential direction and spaced apart from each other by a predetermined distance, and a plurality of coils wound around the magnetic teeth of the stator core via an insulating member, each coil being a stator unit A stator of a rotating electrical machine in which a terminal end toward one end of each of the coils is extended, and a terminal end of each coil is connected to a coil connection terminal of a conductive member, and the insulating member includes a midway terminal part of an adjacent coil The coil wound around the magnetic teeth is provided with a terminal member for electrically connecting the coil and the tip, and the middle point terminal is extended to connect to the coil of another adjacent stator unit so that the adjacent coils are mutually connected. The stator of the rotating electrical machine connected to the. 2. A stator for a rotating electrical machine according to claim 1, wherein the terminal member has a guide portion for guiding a terminal portion of the adjacent coil.

Images