JP2008512980A - Rotating armature of electric starter motor partially impregnated and automobile starter equipped with this rotating armature - Google Patents

Abstract

【Task】
Provided is a rotary armature for an electric starter motor in which the front lead-out line is not impregnated and the heat exchange surface of the front lead-out line is increased.
[Solution]
The rotary armature of the electric motor of the present invention has a predetermined axial distance from the rear lead-out line 43 to the intermediate position of the magnetic circuit 39 in the welded portion 44 where the end portion of the conductor 41 is welded to the blade 45 of the current collector 23. v, partly with a rotor winding impregnated with an impregnant. The present invention is suitable for an automobile starter.
[Selection] Figure 3

Description

  The present invention includes a rotary output shaft that supports a magnetic circuit with a half-open notch, a current collector, and a rotor including a starter head, a half-open notch, protruding on both sides of the magnetic circuit, and a front lead-out line on the starter head side, Further, the present invention relates to a rotary armature of an electric starter motor including a rotor winding having a conductor that forms a rear lead-out line on the current collector side.

  According to the known technique, the conductors contained in the windings of the rotary electrical equipment, in particular the armature of the starter of the automotive internal combustion engine, are fixed by the action of the impregnating lacquer in the notch of the magnetic circuit comprising the laminated metal plates. In the impregnated lacquer, the conductive wires are bonded to each other at the front end and the rear end of the laminated metal plate, and the conductive wire and its housing are bonded at the notch.

  Since the alternator stator described in Patent Document 1 is fixed, it is not affected by centrifugal force, and impregnation is performed on the conductive portion accommodated in the notch. The notch is filled with an impregnating agent over its entire axial length. Further, the insulating layer is formed so that the lead-out line portion is thinner than the conductor accommodated in the notch.

  In addition, another fixing means may be used to enhance the mechanical strength of the conductor in the notch. By using a hoop-shaped glass fiber for the lead wire on the front side of the starter head side or the back side of the current collector side, or both, or as described in Patent Documents 2 to 6 below, the inlet of the notch is pressed. However, the above-mentioned reinforcement may be performed by holding the conductor.

European Patent Publication No. 0881747 French Patent Publication No. 2721769 French Patent Publication No. 2722037 French Patent Publication No. 2726701 French Patent Publication No. 2244284 French Patent Publication No. 2843427

  However, here are the following two problems. The first problem is that the method of applying the impregnated lacquer requires a lot of conditions, which adds to the power required for the lacquer, the application and baking equipment, and the cost required for complex maintenance work. .

  The second problem is that in the front lead-out line, the gap between the rough surfaces is filled in such a way that the lacquer blocks the periphery of the copper wire. As a result, the heat exchange surface where the copper wire and the surrounding air come into contact with each other becomes small, and the heat resistance of the starter may be lowered due to excessive heating.

  An object of the present invention is to provide a rotary armature for an electric starter motor that solves the above-mentioned problems without incorporating a transmission.

  The rotating armature of the electric starter motor according to the present invention has an end portion of the conductor over a certain distance in the axial direction from the rear lead-out line in the welded portion welded to the blade of the current collector to the intermediate position of the magnetic circuit. A rotor winding partially impregnated with an impregnating agent is provided. As a result, the front lead-out line is not impregnated and its heat exchange surface increases. The impregnation distance in the axial direction of the winding is shorter than the total length of the magnetic circuit.

  The impregnating agent is generally lacquer and is applied only to the rear part of the armature on the current collector side. Since the lacquer is not applied to the front lead wire on the starter head side, after lead-out, the surrounding air will be touched more in this part. According to the thermal test, compared with the case where the lead wire impregnated is used. As a result, it was found that the power loss was greatly reduced. Therefore, the heat resistance of the starter is improved. Further, when the armature is rotated, there is an advantage that the amount of lacquer used can be reduced without impairing the resistance during centrifugation.

  According to a preferred embodiment, the intermediate position that is the end point of impregnation is a point that is 1/2 to 2/3 of the axial length of the laminated metal plate that forms the magnetic circuit. The electrical conductor is held in the notch by fixing means that are activated by pressing the magnetic circuit to narrow the entrance to the notch.

In the present invention, in addition to the above, the following features are provided singly or in combination.
The fixing means comprises a pressure contact protrusion formed at at least one locking point of the magnetic circuit;
The locking point is axially separated from the rear end of the current collector side magnetic circuit, the middle locking point being more impregnated forward than the impregnated rear lead line Located near the line.
-In order to protect the rotating armature, an elastic washer is provided, which abuts against the cover, closes the brush housing and suppresses vibrations.

  The starter 10 is for starting a heat engine (in this case, for an automobile), and includes a support 11 fixed to a fixed portion of the automobile as shown in FIG. The support 11 includes a protrusion 12 for attaching a front bearing 13 such as a needle-shaped bearing that coaxially surrounds the tubular sleeve 14 included in the starter head 15.

  A front end of the sleeve 14 protrudes from the protruding portion 12 and is a control pinion 16 that engages with a start ring (not shown) that interlocks with the heat engine of the automobile and starts it.

  The rear end of the sleeve 14 of the starter head 15 is disposed on the inner circumference of a roller 17 belonging to a free wheel located between the pinion 16 and the driver 18.

  The driver 18 includes an internal protrusion 19 that engages with an external protrusion 20 integrated with the output shaft 21 of the rotor 22 included in the electric motor M of the starter. The protrusions 19 and 20 have a complementary spiral shape.

  On the opposite side of the starter head 15, the shaft 21 of the rotor 22 is formed on the current collector 23 by a known method. The current collector 23 is of a shaft type as described in Patent Document 3, for example. The conductive shaft blade of the current collector 23 is structured to be rubbed by the brush 24 acting radially.

  The brush 24 is attached to a housing in a brush holder including a main body (not shown in FIG. 1) having a structure that serves as a support for a plurality of springs so as to meet the above-described purpose. Each spring is here attached radially to the housing in the brush holder and in conjunction with the brush 24 moves the brush in the direction of the conductive blade of the current collector 23.

  The rear end of the output shaft 21 is rotatably attached to a rear bearing 25 such as a sliding bearing, and is held at a sleeve-like central portion of the cover 26. For example, it is the structure described in the said patent document 4.

  A stator 28 can be placed on the casing 27 disposed between the cover 26 and the support portion 11. The stator 28 is provided with an induction coil 28 that coaxially surrounds the rotor 22 via a radial gap. The cover 26 and the casing 27 are connected to the support portion 11 by a tie rod 30.

  More specifically, as described in Patent Document 4, the stator includes a laminated metal plate that is cut so as to define a housing (not shown) of the electric coil 29.

  Plastic receiving pieces (not shown in FIG. 1) are formed on both axial end faces of the laminated metal plate of the stator. This receiving piece is used for winding the coil 29. In addition, a washer (not labeled) is used to close the housing of the brush 24.

  The housing is thus defined by a plastic body (not numbered) of the brush holder and a washer over the body and a partial projection on the cover 26. The main body of the brush holder is in contact with an adjacent receiving piece. The washer is elastic and is configured to suppress vibration in the axial direction. For details, see Patent Document 4 (particularly FIG. 1). In this way, the washer protects the brush and the rotating armature described later.

  The support portion 11 also has a function of placing the cell 31 included in the electromagnetic contactor CT disposed in parallel with the motor above the electric motor M. The contactor CT includes a fixed core 32, at least one excitation winding 33, a movable core 34 that cooperates with fixed terminals 36 and 37 for supplying electric power to the electric motor M, and a movable contact 35 in a known manner. I have.

  A fork-type control lever 38 is pivotally attached on the axis of a rod elastically connected to the movable core 34. The fork-shaped base has two fingers attached to an annular groove in the driver 18 of the starter head 15.

  The rotor 22 includes a magnetic circuit 39 made of stacked metal plates. A hole is formed in the laminated metal plate to support the metal plate in the axial direction on the output shaft 21 by, for example, press-fitting using at least one notched portion of the shaft 21. Each metal plate is provided with a plurality of notches 40 which are radially opened outwardly on the outer periphery thereof. The notches 40 are arranged at equiangular intervals and form an axial groove after positioning the metal plate.

  Each notch 40 accommodates a coiled conductor 41 that passes through the magnetic circuit 39 of the rotor 22. The conductor 41 protrudes in the axial direction at both ends of the magnetic circuit 39, and constitutes a front lead-out line 42 on the starter head 15 side and a rear lead-out line 43 on the current collector 23 side, respectively. The front lead-out line 42 is formed at the tip of the conductor 41. On the other hand, the rear lead wire 43 is composed of an end portion of the conductor 41 connected to the conductive blade of the current collector 23.

  In order not to damage the conductor 41, it is preferable to interpose a notch insulating film between the conductor 41 and the surface defining the notch 40. More specifically, an electrical insulating film such as a coating or enamel indicated by reference numeral 47 in FIGS. 4 and 5 is used. The insulating film 47 covers the conductor 41 made of copper or the like.

  The notch insulating film is preferably formed integrally with the magnetic circuit 39, more specifically, a laminated metal plate constituting the main body of the rotor 22 integrated with the shaft 21.

  1 to 3, a series of superimposed conductors 41 are provided for each notch 40, and form a rotor winding. As an example, four conductors 41 are provided for each winding, and are superimposed in the notch 40 in the winding operation.

  The cross section of the winding is initially circular, but after being compressed by a plate-like tool with a pressure punch, it becomes a crushed shape, as clearly shown in FIGS. After that, the laminated metal plate of the magnetic circuit 39 is pressed by the press-contact punch of the plate-like tool, particularly at one or more locking points A, B, C as shown in the three examples in FIG. Locked to each conductor. This locking is performed by, for example, the press contact method described in Patent Document 2 above.

  According to this method, by partially folding a part of the metal plate above the notch 40, the entrance to the notch is narrowed and the lead wire is mechanically prevented from popping out.

  As described above, the three engagement points A, B, and C in the peripheral portion further cause adhesion within the notch 40 due to adhesion caused by the overlapping conductors contacting each other and adhesion between the conductor and the inner wall of the notch 40. The mechanical strength of the conductor 41 is exhibited.

  In the present invention, the rotor windings are further reinforced by partial lacquer impregnation. In FIG. 3, the amount of lacquer applied in the notch 40 of the armature has decreased and is only behind the armature on the side of the current collector 23, ie, the mechanical strength of the conductor subjected to centrifugal force when the current collector 23 rotates. Impregnation is applied only to the part where is more important.

  The front lead-out line 42 on the starter head 15 side is not coated with lacquer or other impregnating agents except for the insulation for the lead-out line. The lacquer-impregnated portion of the conductor 41 extends from the welded portion 44 at the end of the conductor 41 to an axial distance v from the current collector 23 to the conductive blade 45 of the current collector 23. This corresponds to approximately 1/2 to 2/3 of the total length z of the magnetic circuit 39. The impregnation lacquer is not applied also to the active region u of the blade 45 of the current collector 23.

  The locking points A, B, and C are separated from the rear end of the magnetic circuit 39 on the current collector side by distances l1, l2, and l3, respectively. The intermediate locking point B is located closer to the front lead-out line 42 that is not impregnated than to the rear lead-out line 43 that is impregnated with lacquer.

  By not applying the lacquer to the front lead wire 42, the heat exchange surface where the conductor 41 and the surrounding air come into contact increases. FIG. 4 shows that the heat exchange surface S of the lead wire subjected to the impregnation lacquer 46 in the prior art is smaller than the heat exchange surface S 'of the lead wire not subjected to the impregnation lacquer shown in FIG. In any case, the conductor 41 is electrically insulated by a normal method using an insulating coating 47 for enlarging electrical insulation between various conductors or an enamel layer.

  Thus, the increase in the heat exchange surface of the front lead-out line 42 improves the ventilation and heat resistance inside the starter, and when the electric motor M is manufactured, the amount of lacquer used is reduced, and the impregnation device is reduced. A simple structure can be obtained. There is no need to provide hoops for holding the conductors 41 in the lead wires 42 and 43 radially.

  This partial impregnation can be applied to any type of wound armature, and can also be applied to the hairpin winding described in Patent Document 5 above. It can also be applied to any kind of starter that starts a heat engine.

  The range of application includes all types of starters ranging from minicars to heavy-duty vehicles, and because of the low armature rotation speed, there is no starter with no built-in gearbox with little risk of centrifugal separation of conductors. Especially mentioned.

  It is clear that the elastic washer of the brush holder has the function of protecting the front lead-out line that is not lacquered by suppressing axial vibrations.

  The current collector 23 may be a surface type, and the brush may act in the axial direction. Similarly, the pinion 16 of the starter head 15 may be attached to the inside of the support 11.

  The free wheel located between the pinion 16 of the starter head 15 and the driver 18 includes a friction concave surface included in one of the starter head 15 and the pinion 16 and a friction convex surface included in the other of the starter head and the pinion. A configuration like a clutch may be used.

  As a modification, the contactor CT may be attached to the rear of the electric motor M and perpendicular to the axis of the output shaft 21. At this time, as described in Patent Document 6, the fork-shaped tip of the control lever 38 includes an auxiliary rod extending in parallel with the electric motor M, and a rod connected to the movable core 34 and the auxiliary rod. Connected to a return mechanism operating between.

  The contactor in the modified example is attached in front of the electric motor, and the movable core of the contactor is a starter head, so that the control lever 38 is unnecessary.

  The number of conductors accommodated in each notch varies depending on the application.

FIG. 1 is a longitudinal sectional view of a starter equipped with a rotary armature according to the present invention. FIG. 2 is a longitudinal sectional view of the rotating armature of FIG. 1 showing the locking position of the metal plate of the magnetic circuit for the mechanical strength of the conductor in the notch. FIG. 3 is a diagram showing a partial impregnation site of the rotary armature of FIG. FIG. 4 is a schematic cross-sectional view of an armature lead-out line with impregnation lacquer in the prior art. FIG. 5 is a view similar to FIG. 4 showing an armature according to the present invention in which the lead-out line is not impregnated with an impregnation lacquer.

Explanation of symbols

M Starter motor 15 Starter head 21 Rotation output shaft 22 Rotor 23 Current collector 39 Magnetic circuit 40 Half-open notch 41 Conductor 42 Front lead-out line 43 Rear lead-out line 44 Welding part 45 Blade

Claims (10)

A rotor (22) comprising a rotary output shaft (21) supporting a magnetic circuit (39) in a half-open notch (40), a current collector (23), and a starter head (15);
It is accommodated in a half-open notch (40), protrudes on both sides of the magnetic circuit (39), and extends to the front lead line (42) on the starter head (15) side and the rear lead line (43) on the current collector (23) side. A rotary armature of an electric starter motor (M) comprising a rotor winding having a conductor (41) forming
The rotor winding includes a magnetic circuit (39) from a rear lead-out line (43) in a welded part (44) in which an end of the conductor (41) is welded to a blade (45) of the current collector (23). ) Is partially impregnated with an impregnating agent over a certain distance (v) in the axial direction to the intermediate position, so that the front lead-out line (42) is not impregnated and the front lead-out line A rotating armature characterized by an increased heat exchange surface.   The rotary armature according to claim 1, wherein the axial distance (v) for impregnating the winding is shorter than the total length (z) of the magnetic circuit (39).   The said intermediate position which becomes an end point of impregnation is a location of 1/2 to 2/3 of the axial length (z) of the laminated metal plate forming the magnetic circuit (39). Rotating armature.   The conductor (41) is held in the notch (40) by fixing means which are activated by pressing the magnetic circuit (39) to narrow the entrance to the notch (40). The rotating armature according to claim 1.   5. The rotary armature according to claim 4, wherein the fixing means comprises a pressing contact projection formed at at least one locking point (A, B, C) of the magnetic circuit (39).   The locking points (A, B, C) are separated from the rear end of the magnetic circuit (39) on the current collector (23) side by an axial distance (l1, l2, l3). 6. Rotation according to claim 5, characterized in that the locking point (B) is located closer to the non-impregnated front lead-out line (42) than to the impregnated rear lead-out line (43). Armature.   2. A rotary armature according to claim 1, wherein the impregnating agent is lacquer.   The rotary armature according to claim 7, wherein the conductor (41) of the rotor winding comprises a coil winding or a hairpin winding. An automotive starter having an electric motor (M) having a rotary armature and controlled by a contactor (CT),
The said rotary armature is a starter for motor vehicles which has the structure of Claim 1. A brush holder having a body defining a housing for scrubbing the conductive blades of the current collector by a resilient washer;
The rear end of the shaft (21) of the rotor (22) is rotatably attached to the rear bearing at the center of the cover (26), and the elastic washer abuts against the cover, The automobile starter according to claim 9, wherein the starter is configured to suppress vibration by being closed.

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