KR100412511B1 - A small motor - Google Patents

Abstract

It is an object of the present invention to provide a small motor capable of reducing the number of components constituting the terminal portion and simplifying the attachment structure of the circuit board portion, thereby making it possible to miniaturize and increase the space of the lubrication portion.

In order to solve this problem, a cutout is formed in a part of the motor case, and in the small motor having a connector part connected to an external connector for energizing the motor coil, the connector part is connected to the external connector inserted from the outside. (24) and the cover portion (25) having an opening portion (25b), which is a storage space of the external connector, are integrally molded by fixing or synthetic resin, and the flexible substrate (23) is formed by the motor coil and the connector portion (24) as the energizing member. It is in the structure interposed between).

Description

Small Motors {A SMALL MOTOR}

The present invention relates to a small motor for fitting a connector to a connector housing and performing electrical bonding.

Conventionally, a small motor disclosed in Japanese Patent Laid-Open No. 10-14170 as shown in Fig. 11 is known. The terminal portion 202 corresponding to the supply of current to the coil of the small motor 201 has a terminal pin 205 disposed in the middle of two coils 203 and 204, and is fixed by inserting the terminal pin 205. A holder member 206, a circuit board 207 fixed to the holder member 206, a connector housing 208 electrically connected to the circuit board 207, and a cover 209 covering these members. It consists of).

The assembly of the terminal portion in the conventional small motor 201 will be described. First, the circuit board 207 is inserted into the holder member 206 into the circuit board insertion hole, and one surface is brought into contact with the holder member 206. Subsequently, the holder member 206 and the circuit board 207 are moved to the coil bobbin 211 so that the terminal pins 205 fixed to the coil bobbins 211 and 212 penetrate the holder member 206 and the circuit board 207. 212). Thereafter, the connector housing 208 is attached to the holder member 206 and the connection terminal is fixed to the circuit board 207. Then, the circuit board 207 is soldered to the terminal pin 205 and finally the cover 209 is attached.

The cover 209 is fitted to the cutout (not shown) of the cylindrical case 213 and is coupled to the flat case 214 so as not to be released from the small motor 201. In this manner, the cover 209 serves as the outer cover of the connector housing 208 and also functions as a case of the small motor 201 in cooperation with the cylindrical case 213 and the flat case 214.

The terminal portion of the small motor 201 shown in Japanese Patent Application Laid-Open No. 10-14170 is composed of a holder member 206, a circuit board 207, a connector housing 208, and a cover 209, and is assembled in a complex manner. have. In particular, the attachment structure to the other member of the terminal part of the connector housing 208 becomes complicated. As described above, the terminal portion of the conventional small motor 201 uses a plurality of components and is complicatedly assembled, which is disadvantageous in terms of workability and cost.

In the conventional small motor 201, the structure of the holder member 206 is complicated by the attachment of the circuit board 207. In addition, in order to prevent the terminal portion of the small motor 201 from protruding, the thickness of the circuit board 207 is considered and the thickness of the holder member 206 is suppressed. However, the holder member 206 also requires a certain thickness and tends to increase in the radial direction as a whole. In addition, since the circuit board 207 and the holder member 206 enter the lubrication portion 215 of the small motor 201, the space in which the lubrication portion 215 is disposed is narrowed, making the gear and the like small. Will be restricted.

SUMMARY OF THE INVENTION The present invention has been made in view of solving the above-mentioned problems, and aims to provide a small motor which is advantageous in terms of cost and excellent workability and manufacturing efficiency as well as reducing the number of parts constituting the terminal portion. Still another object of the present invention is to provide a small motor which can simplify the attachment structure of the circuit board portion, which can be miniaturized, and which can increase the space of the lubrication portion.

1 is a side cross-sectional view of a small motor of a first embodiment of the present invention.

FIG. 2 is a plan view illustrating a gear transmission mechanism of the small motor of FIG. 1. FIG.

Figure 3 is a side view of the cutout of the cylindrical case of the small motor of Figure 1;

4 is a front view of the connector member used in the small motor of FIG.

5 is a plan view of the connector member used in the small motor of FIG.

6 is a bottom view of the connector member used in the small motor of FIG.

7 is a cross-sectional view taken along the line B-B in FIG. 4.

8 is a plan view of a stop plate portion of the small motor of FIG.

9 is a side cross-sectional view of a small motor as a second embodiment of the present invention.

10 is a side cross-sectional view of a small motor as a third embodiment of the present invention.

11 is a side cross-sectional view of a conventional small motor.

In order to achieve the above object, the invention described in claim 1 cuts a part of the motor case to form a cutout, and in the small motor in which a connector member having a connector part connected to an external connector for energizing the motor coil is fixed to the cutout. The connector member is integrally arranged with a cover portion covering the cutout portion.

In the invention according to claim 2, in the small motor according to claim 1, the connector member is molded by integral molding of a connector part and a cover part by synthetic resin.

In the invention according to claim 3, an external connector is attached to a connector housing having an extreme value arranged in a circular shape constituting the stator portion and a motor coil wound around the extreme value, and the electrical connection to the terminal pin to which the coil is connected to the motor. In a small motor configured to be connected by connecting, a connector part to which an external connector to be inserted from the outside is connected, and a cover part having an opening to be a storage space of the external connector are integrally molded by fixing or synthetic resin so that both are integrated. have.

According to a fourth aspect of the present invention, in the small motor according to claim 1 or 3, the arm portion extending from the inside of the cover portion to the outside is disposed, and a locking portion for preventing the connection from being released after the external connector is connected to the connector portion. The locking member is arranged separately from the connector member, and the locking member is bent by the arm when the external connector is connected to the connector, and allows the connection with the external connector. When the external connector is connected, the bending of the arm is restored to restore the external connector. It is set as the structure which prevents falling out.

In the invention of claim 5, in the small motor according to claim 4, the arm portion is configured to extend from a receiving stand supporting an energizing member between the terminal of the motor coil and the connector pin fixed to the connector portion.

In the invention according to claim 6, in the small motor according to claim 5, the support base is fixed to the stator core to which the motor coil is wound.

In a seventh aspect of the present invention, in the small motor of the fifth aspect, the receiving stand passes through a press-fit fixing part arranged to press-fit the stator core to which the motor coil is wound, and a terminal pin to which the terminal of the motor coil is connected. The terminal pin window is arranged as a through hole to enable solder connection. Further, in the invention of claim 8, in the small motor according to claim 1 or 3, a flexible substrate as a conduction member is interposed between the terminal of the motor coil and the connector pin fixed to the connector portion.

In the invention of claim 10, a part of the motor case is cut out to form a cutout portion, and in the small motor having a connector member having a connector portion to which an external connector for energizing the motor coil is connected to the cutout portion, the terminal of the motor coil is fixed. And a flexible substrate serving as an energizing member is interposed between the connector pins fixed by the connector portion.

In the invention of claim 10, the flexible board is a single-sided flexible board having a circuit formed only on one side thereof, and the circuit is formed by connecting the terminal of the motor coil and the flexible board and the connection between the connector pin and the flexible board. It is configured to perform only on one side.

In the invention according to claim 11, in the small motor according to claim 1, 3 or 10, the connector portion is formed so that the external connector can be connected in parallel with the motor circuit shaft.

In the invention according to claim 12, in the small motor according to claim 11, an inclined portion for smoothly guiding the external connector is formed at the inlet of the connector portion. In the invention according to claim 13, in the small motor according to claim 1, 3 or 9, the contact surface of the connector portion when the external connector is connected is located at the insertion side of the external connector further from the center of the axial direction of the small motor. It consists.

The connector member serving as the terminal portion of the present invention has a structure in which the connector portion and the cover portion are integrated. The function of the terminal portion composed of the conventional connector housing and cover is satisfied with the integrated connector member. At the same time as the number of parts decreases, a complicated structure as in the prior art becomes unnecessary.

An embodiment of the present invention will be described with reference to FIGS. First, the small motor of the first embodiment will be described with reference to Figs.

First, the structure of the terminal part and the receiving stand used as the point of this invention is demonstrated with reference to FIGS. The connector member 6, which is a terminal portion, includes a connector portion 24 to which a connector to be inserted from the outside is connected, and a cover portion 25 having an opening 25b to serve as a storage space for the connector to be inserted from the outside. It integrally shape | molds by this and becomes what integrated both.

The connector portion 24 is arranged integrally with the cover portion 25 in the center of the cover portion 25 to be described later to fix the connector pin 24a and the flexible substrate 23 constituting the energization path.

The cover portion 25 is a groove (25a) arranged to cover and fit the cutout portion (11a) of the cylindrical case 11 on both ends of the cover portion 25, as shown in Figs. The opening 25b disposed as a storage space of the external connector inserted from the outside, the connector guide 25c arranged on both sides to introduce the external connector inserted from the outside, and being guide grooves, and the insertion of the external connector inserted from the outside In combination with the two insertion confirmation window (25d) arranged to confirm, the locking window (25e) arranged to pass through the locking member (22a) arranged to extend from the inside to the outside, and the flat case 20 in combination The connector part 24 which has the coupling pin 25f arrange | positioned at the upper two places so that it may not deviate from the motor 1, and is shape | molded and arrange | positioned by integral molding is arrange | positioned.

In the opening portion 25b disposed in the cover portion 25, a curved inclined portion 25g, which is an inclined portion with rounded corners, is disposed at the tip of the inner portion of the entrance to improve the insertion operation of the external connector inserted from the outside. Moreover, the connector part 24 is arrange | positioned in the vicinity of the axial cross section which becomes a position on the opposite side to an output shaft so that the insertion workability of an external connector inserted from the outside may be improved. In other words, the abutting surface 24b of the small motor 1 is struck in the axial center of the small motor 1 so that the external connector can be coupled to the connector pin 24a by inserting the external connector slightly from the bottom side of the small motor 1. It is arranged to come to the bottom side.

In the receiving stand 22, the locking member 22a for preventing the insertion of the external connector inserted as shown in FIG. 1 and the stator constituting the extreme value 8 (the upper stator portion 8a in FIG. 1) are press-fitted and fixed. Terminal pin window 22c, which is a through-hole arranged to allow solder connection by passing the arranged press-fit fixing part 22b and the terminal pins 21 and 21 of the motor coils 9 and 10 from the support base 22. ) Is placed.

The energizing member to the motor coils 9 and 10 is connected to the flexible board 23 soldered to the terminal pins 21 of the motor coils 9 and 10 as shown in FIG. It consists of the connector pin 24a. The flexible substrate 23 is a single-sided flexible substrate with wiring on one side, but may be a double-sided flexible substrate with wiring on both sides.

In addition, the terminal pin window 22c not only allows the terminal pin 21 to pass therethrough, but also supports the support portion 9b of the terminal pin 21 of the coil bobbin 9a for fixing the terminal pin 21 from one side thereof. have. By this configuration, the support stand 22 enters the vicinity of the winding surface of the motor coils 9 and 10, which can reduce the size of the small motor 1 in the radial direction and at the same time the motor coils 9 and 10. The winding of the can be prevented from falling.

The locking member 22a disposed on the support base 22 is arranged to protrude laterally from the bottom of the support base 22 and also in the portion surrounding the terminal pin window 22c as shown in FIG. 1. The locking member 22a has an arm portion and a locking portion whose tip is bent at right angles to face the connector pin 24a side. And the locking member 22a receives the force shown by arrow A of FIG. 1 when inserting an external connector, and has the elastic force bent in the arrow A direction. When the external connector fits into the opening portion 25b of the cover portion 25 and is connected to the connector pin 24a, the locking member 22a is restored to its original position, and the back of the external connector and the locking portion of the locking member 22a are lined up. The end face 22d is opposite, and the external connector cannot simply be separated.

As the energizing member, the flexible substrate 23 extends in the horizontal direction along the connector portion 24 from the connection with the connector pin 24a as shown in FIG. 1, and then bends downward at a right angle and again near the locking member 22a. It is bent at a right angle and then bent at a right angle upward again along the base 22. And it is soldered in the terminal pin 21 and the terminal pin window 22c. In this way, the flexible substrate 23 is bent several times and is connected to the terminal pin 21 or the connector pin 24a in a relaxed state, so that a force is applied when fitting the external connector to the connector pin 24a. Even if the position of the 24a or the connector 24 is shifted or reduced, the influence does not reach the soldered portion of the terminal pin 21, so that the connection of the terminal pin 21 is maintained in a stable state.

In addition, since the flexible substrate 23 is bent as shown in Fig. 1, a single-sided flexible substrate having a circuit formed only on one side can be adopted, and soldering is performed on only one side. In addition, since the use of the flexible board 23 does not require the use of the circuit board 207 having the same thickness as in the prior art, it is possible to reduce the size of the small motor 1 in the radial direction. Further, a space is formed in the upper portion of FIG.

The connector member 6 has a small motor 1 compared to the configuration in which the opening 25b is in the direction parallel to the axial direction of the small motor 1, that is, directly downward in FIG. Can be reduced in size in the radial direction. In addition, the connector portion 24 is arranged on the bottom side of the prior art and the flexible substrate 23 is used, so that the upper space S of the connector portion 24 becomes wider, and the connector pins 24a and the flexible substrate 23 are larger. It will be easier to solder with.

As shown in Fig. 1, the small motor 1 is composed of a stator part 2, a rotor part 3, a gear transmission mechanism 4 which is a gear reducer gear train, an output shaft 5, and a connector member 6; It consists of a stepping motor. And the stator part 2 and the gear transmission mechanism 4 are arrange | positioned adjacent to the axial direction.

The stator part 2 has extreme values 7 arranged in a circular shape in which the tip ends of two stators are intertwined alternately, extreme values 8 arranged in the axial direction with the extreme values 7, and extreme values ( A coil 10 wound around the outer periphery of 7) and a cylindrical case 11 serving as a stator are formed. In addition, the coil 9 is wound around the extreme value 7 through the coil bobbin 9a, and the coil 10 is wound around the extreme value 8 through the coil bobbin 10a.

The rotor part 3 is comprised from the fixed rotor shaft 13 and the rotor 14 rotatably supported by this rotor shaft 13 which has the magnet 14a.

The gear transmission mechanism 4 includes a pinion 14b formed on the rotor 14 as shown in FIG. 2, a first gear 15 engaged with the pinion 14b, and a first gear 5. 2nd gear 16 to be engaged, 3rd gear 17 to mesh with this 2nd gear 16, 4th gear 18 to mesh with this 3rd gear 17, and 4th gear It consists of the gear 5a arrange | positioned at the output shaft 5 so that it may engage with (18). Moreover, this gear transmission mechanism 4 becomes a deceleration mechanism, and the pinion 14b and each gear 15, 16, 17, 18, 5a decelerate and transmit rotation.

The stop plate 19 made of synthetic resin has a circular hole 19a disposed at the center to pass through the rotor shaft 13, and a circular support portion having a thick width surrounding the circular hole 19a. 19b), two support parts 19c and 19c, and two fitting protrusions (not shown) for positioning with a stator are integrated. Moreover, the base board contact part 19e which the base stand 22 contacts is arrange | positioned at the stop plate 19 by cutting out the outer peripheral part of the stop plate 19 in circular arc shape. The outer circumferential portion of the stator portion 8a is exposed to this cutout portion. And the exposed part is fitted into the press fitting part 22b of the base stand 22, and the base stand 22 is being fixed (refer FIG. 8). Moreover, the outer periphery of the bobbin 10a by the side of the base stand contact part 19e is also cut | disconnected so that it may become the same shape as this base stand contact part 19e, and becomes a straight line which can contact the base stand 22. As shown in FIG. By such a configuration, the base 22 is reliably fixed and the width in the radial direction of the small motor 1 is not increased.

The circular bearing portion 19b protruding in the axial direction is positioned and fixed in the radial direction by being fitted into a circular hole in the center portion of the stator surrounding the rotor portion 3 as shown in FIG.

Next, another Example of this invention shown in FIG. 9 and FIG. 10 is demonstrated. In addition, in the description of another embodiment of the present invention, the same reference numerals are given to the same constituent parts of the first embodiment of the present invention, and redundant descriptions are omitted.

In the second embodiment of the present invention of FIG. 9, the difference from the first embodiment is the shape of the connector pin 24a fixed to the connector portion 24 and the length of the flexible substrate 23 accordingly. The connector pin 24a bends the tip of the connector 24 into the internal space of the small motor 1 by 90 degrees. The connector pin 24a is soldered and connected to the flexible substrate 23 in the vicinity of the support base 22. The connection between the flexible board 23 and the connector pin 24a is a terminal board 21. The length of the flexible substrate 23 can be made shorter than that of the first embodiment because it is performed at a position close to).

The soldering work between the connector pin 24a and the flexible board 23 is performed because the bent tip portion 24c is placed on the front side of the connector member 6 instead of the inside, and the soldering portion becomes the front side. Is improved. In addition, the bent tip portion 24c protrudes toward the front side, whereby the upper space S surrounded by the connector portion 24 and the cover portion 25 can be enlarged. Also in this embodiment, the flexible substrate 23 is soldered on one side as a one-sided flexible substrate, but a double-sided flexible substrate may be used.

The difference from the first embodiment in the third embodiment of the present invention in FIG. 10 is the tip shape of the cover portion 25 and the shape of the support base 22. The cover portion 25 is a cover portion freely open and closed between the upper end portion 25j on which the fitting pin 25f is disposed and the connector portion 24 fixing the connector pin 24a so that soldering can be easily performed. Has 25 h.

On the other hand, the base 22 is provided with a protrusion 22e for sandwiching the tip of the lid 25h between the upper ends 25j when the lid 25h is closed. The use of the cover portion 25 having the lid portion 25h and the receiving stand 22 having the projection portion 22e in pairs makes soldering much easier. This is because soldering can be performed while the lid portion 25h is open. After the soldering of the terminal pin 21 and the flexible substrate 23 of the motor coils 9 and 10 is completed, the connector member 6 is fitted to the cutout portion 11a of the cylindrical case 11. The flat case 20 is attached. Then, the solder pin 24a and the flexible substrate 23 can be soldered. When the soldering is finished and the lid portion 25h is closed, the tip of the lid portion 25h is sandwiched between the upper end portion 25j of the cover portion 25 and the protrusion portion 22e of the holder portion 22, and the support portion 22 ) Is correctly supported.

In the case of the small motor 1 of the first or second embodiment, the soldering operation of the connector pin 24a and the flexible board 23 is performed before or after the connection between the terminal pin 21 and the flexible board 23. FIG. As the connector member 6 must be soldered before attaching the connector member 6 to the small motor 1, the connector member 6 is performed in an unstable state. On the other hand, in the third embodiment, after attaching the connector member 6 to the small motor 1, soldering of the connector pins 24a and the flexible 23 can be performed, thereby improving solderability.

In addition, although each Example mentioned above is an example of a suitable embodiment of this invention, various modifications are possible in the range which does not deviate from the summary of this invention. For example, the small motor may be an AC small synchronous motor, a small DC motor, or the like in addition to the stepping motor.

In addition to the integration by the resin molding, the integration of the connector portion 24 and the cover portion 25 may be fixed to each other with an adhesive or the like. In addition, the part supporting the flexible substrate 23 of the support base 22 may be removed, and the part corresponding to the locking member 22a may be arrange | positioned at the connector part 24. As shown in FIG. In addition, the direction of the opening portion 25b of the portion in which the connector portion 24 and the cover portion 25 are integrated may be inclined downward or upside down in the same manner as in the prior art so as to be upward or radially outward.

As can be seen from the above description, each invention can obtain the effects listed below.

In each invention of Claims 1, 2 and 3, since the connector part and the cover part are integrated together, there is no need for complicated assembly. Simplification of assembly improves the quality of the product and at the same time the parts management is not cumbersome, greatly reducing the number of processes and improving the manufacturing efficiency. In the invention of Claim 2, since both are integrated by integral molding of the resin, the manufacturing efficiency is further improved.

In addition, according to the invention of claim 4, the connector from the outside inserted into the opening portion facilitates the insertion work by the bending action of the arm portion, and the external connector once inserted does not fall out by the action of the locking portion.

In addition, in the invention of claim 5, the length of the arm portion extending from the support base easily causes warpage, and the warp provides ease of insertion work of the insertion connector from the outside and prevention of detachment of the external connector. Moreover, since the locking member is formed in the support base which supports the electricity supply member, it is unnecessary to arrange | position a locking member specially as one component, or to fix it individually to a case member etc.

In addition, in the invention of claim 6, the support stand is fixed to a strong stator core, so that the support stand can be attached in a stable state, and the fixing work is simplified. In addition, in the invention of claim 7, the terminal pin connected to the terminal of the motor coil protrudes through the terminal pin window of the support base, so that the soldering operation of the terminal pin and the energizing member becomes easy.

In the invention according to claim 8, the flexible substrate, which is a good conduction path, exhibits flexibility, and even if an extra force is applied to the terminal portion, the flexible substrate, or the like during soldering, the influence can be prevented from appearing on other connecting portions. In addition, the use of the flexible board eliminates the need to use a circuit board having the same thickness as in the prior art, thereby making it possible to reduce the size of the small motor in the radial direction and increase the space of the gear transmission mechanism that becomes the lubrication mechanism.

In addition, in the invention of claim 10, since a flexible substrate is provided as a conduction path, for example, a force is applied when fitting a connector from the outside to the connector pin, so that even if the position of the connector pin or the external connector is shifted or expanded, Silver does not extend to terminal pin, so connection is kept stable. In addition, by using the flexible board, it is not necessary to use a circuit board having the same thickness as in the prior art, so that the size of the small motor can be reduced in the radial direction and the space of the gear transmission mechanism that becomes the lubrication device can be increased.

In addition, in the invention of claim 10, since the single-sided flexible substrate can be used, the energization path becomes low cost. In addition, since the connection is made only on one side of the single-sided flexible substrate, the connection work can be performed from the same side of the flexible substrate and the work efficiency can be increased. In addition, in the invention of claim 11, since the external connector can be inserted directly under the small motor, the insertion operation of the external connector is improved. It also eliminates the need for extra space for insertion.

In addition, in the invention of claim 12, the external connector is fitted smoothly along the inclined portion to facilitate the insertion operation. In addition, in the invention of claim 13, by slightly plugging in the external connector, the connector can be combined with the connector, thereby making the connection work efficient.

Claims (13)

In a small motor in which a part of the motor case is cut out to form an incision, and a connector member having a connector portion to which an external connector for energizing the motor coil is connected to the incision is fixed, wherein the connector member includes a cover portion covering the incision. Small motors, characterized in that arranged integrally. The method of claim 1, The connector member is a small motor, characterized in that the connector portion and the cover portion is molded by integral molding by synthetic resin. A small motor having a pole arranged in a circular shape constituting the stator portion and a motor coil wound around the pole, and configured to perform electrical connection to the terminal pin to which the coil is connected by connecting an external connector to a connector housing attached to the motor. The small motor according to claim 1, wherein the connector portion to which the external connector to be inserted from the outside is connected and the cover portion having the opening to be the storage space of the external connector are integrally formed by fixing or synthetic resin to integrate the both. The method according to claim 1 or 3, A locking member having an arm portion extending outwardly from the inside of the cover portion and a locking portion for preventing the connection from being released after the external connector is connected to the connector portion, and the locking member is disposed separately from the connector member. When the external connector is connected to the connector portion, the female portion is bent to allow the connection with the external connector and at the same time when the external connector is connected, the bending of the female portion is restored to prevent the external connector from falling out. Small motor. The method of claim 4, wherein The female motor is characterized in that the small motor is extended from the receiving stand for supporting the conduction member between the terminal of the motor coil and the connector pin fixed to the connector. The method of claim 5, The receiving stand is a small motor, characterized in that the motor coil is fixed to the stator core is wound. The method of claim 5, The support base has a press-fit fixing part arranged to press-fit the stator core to which the motor coil is wound, and a terminal pin window arranged as a through hole to allow solder connection by passing through a terminal pin to which the terminal of the motor coil is connected. Small motor, characterized in that. The method according to claim 1 or 3, A small motor, characterized in that a flexible substrate as a conduction member is interposed between the terminal of the motor coil and the connector pin fixed to the connector. delete A small motor in which a part of the motor case is cut out to form an incision, and a connector member having a connector part to which an external connector for energizing the motor coil is connected to the incision, is fixed to the terminal of the motor coil and the connector part. Interposed between the connector pins as a flexible substrate as a conducting member, The flexible substrate is a one-sided flexible substrate having a circuit formed only on one side thereof, and both the terminal of the motor coil and the flexible substrate and the connector pin and the flexible substrate are connected only on one side of the circuit. Small motor, characterized in that to be. The method according to claim 1, 3 or 10, The connector unit is a small motor, characterized in that the external connector is formed to be connected to move in parallel to the motor axis of rotation. The method of claim 11, Small motor, characterized in that the inclined portion formed to guide the external connector smoothly at the inlet of the connector. The method according to claim 1, 3 or 10, And the contact surface of the connector portion is further located at the insertion side of the external connector at the axial center of the small motor when the external connector is connected.