DE8505664U1 - Collector motor with assigned tachometer generator - Google Patents

Description

PRINZ, LEISBRi- ^ UWsE-Sc

P.-itcntfinwfilte .'... fcuropfeim ".Watijnt '.Allfif Fieys

Munich Stuttgart

February 27, 1985

SOCIETE ELECTROMECANIQUE DU NIVERNAIS SELNI 166, rue des Grands Champs

58000 Nevers / France

Our reference: S 3246

Collector motor with assigned tachometer generator

The invention relates to a direct current motor, in particular in series, and a universal motor which is assigned to a speedometer generator which has a signal indicating the speed of rotation of the motor generated so that the speed of rotation can be controlled.

As is known, DC motors contain an inductor which forms the stator and which is usually made up of one on the poles Magnetic circuit applied windings is formed and generates a magnetic constant field, as well as rotor windings, the ends of which are connected to diametrically opposed collector lamellas and on which grinders expire. The sliders take a fixed position and have the task of winding the rotor one after the other to supply electricity or these rotor windings

HD / kn

short-circuit one after the other. The rotation of the engine is obtained by the action of the magnetic field on each winding through which a current flows or short-circuited.

In the case of a DC motor with excitation in series, the inductors are in series for the power supply switched with the rotor coils.

IQ A universal motor has the same structure as a DC motor with series excitation; however, it is fed with alternating current.

It is also known that in such motors the rotational speed greatly different from that given by the burden

Torque depends. For this reason, such motors are often assigned control devices, the task of which is to keep the speed of rotation constant. Such control devices usually contain a _on tachometer generator, having a magnet which attached to the motor shaft and is surrounded by a coil. The rotation of the magnet in relation to this coil induces a current in it, the strength of which depends on the speed and which is used

is used to generate the 25th in each half cycle of an alternating current

To control the duration of the conductive state of a triac, which is in series with the power supply of the motor in order to keep its speed constant.

It has been found that in such universal motors or DC motors, the noise level in operation for is too high for certain applications, especially for domestic use. In addition, one of the camps becomes quickly burdened with dirt, causing premature

Wear and tear can be caused and further noise-35

development arises.

The invention is based on the object of remedying these deficiencies.

According to the invention, the tachometer generator is between the collector and a bearing, in particular a ball bearing, arranged with the rotor fixed on the motor shaft, and one side wall of the non-rotating Part of the speedometer generator is located opposite the circumference of the collector so that it forms a screen, which keeps dust away from the bearing, which is caused by the friction of the brushes or grinders on the collector lamellas arises. This screen, the design of which is particularly simple, reduces wear on the bearing and counteracts a corresponding increase in noise development, moreover is the speedometer generator housed in the same housing as the engine, creating an additional housing for this speedometer generator can be omitted.

^The noise development can be further reduced if the unit consisting of motor and generator is assembled as follows: The rotor group of the motor, which includes the rotor windings, the collector, the two bearings, the magnet of the tachometer generator between the collector and a bearing and, if necessary, one Contains pulley for driving a load, is mounted on the shaft separately from the stator group and is then dynamically balanced to avoid imbalances; Finally, the final assembly of the motor is carried out by placing the rotor assembly in the housing.

According to the state of the art, the tachometer generator forms an attached unit that is used for dynamic balancing was not taken into account in the manufacture of the engine. The magnet of the generator could therefore Cause imbalances, which led to the development of noise.

Further features and advantages of the invention emerge from the following description of exemplary embodiments and from the drawing, the sole figure of which shows an axial section of a motor according to the invention.

The embodiment shown in the drawing forms a universal motor, i.e. a motor that can be operated with either direct current or alternating current and is widely used in domestic applications, particularly as a drum drive motor for washing machines.

This motor contains a stator 10 formed from magnetic or magnetizable sheets, the sheets of which extend perpendicular to the axis 11 of the motor and covered by a sheath 12 made of thermoplastic or polymerizable material are held together in the form of a stack, the envelope on the one hand includes two end walls 13 and 14 which bear against the outer surfaces of the outermost sheets, and on the other hand cross struts 15.

The stator formed from sheet metal has two poles (which are not illustrated in the drawing) which the inductor windings 9 are wound.

The casing 12 forms a support for housing elements 16 and 17, which in the embodiment shown are metallic are and each have the shape of a cylinder part, which extends over a fraction of the circumference of the engine extends. In the axial direction, each of these elements 16 and 17 extends over a greater length than the inductor or stator 10, the protruding part on the side of the wall 14 being larger than the one on the side of the wall 13.

The side wall 14 of the casing 12 is firmly connected to a connection device 17, the task of which is

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to guide and connect the connecting conductors and / or control conductors. This facility
Slider guides 18 and 19.

to connect. This device 17 also carries the

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Furthermore, the motor has a wound rotor 20, the windings 21 of which with the lamellae 22 of a collector 23 are connected, against which the brushes or grinders 24, 25 are pressed.

The device 17 has a transverse end

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surface 2 6, which assumes the same position in the axial direction as the end of the collector 23, which the Windings 21 of the motor 2 0 is opposite. On the end wall 2 6 .. is the winding 27 of a tachometer generator 28 attached, the magnet 29 of which is attached to the shaft 32 of the motor.

To fasten the winding 27, fingers 50 protrude from the surface 26 of the part marked 17_

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extend in the axial direction and each in the form of a Hook 51 are bent. Each finger 50 is flexible in the radial direction to allow installation of the winding 27, which are fixed in this way on the one hand between the surface 26 and on the other hand between the hooks 51 is. The housing of the winding 27 has a side wall 52 which extends in the radial direction on both sides of the periphery 54 of the collector 23 to form a protective screen that keeps the dust out, which is caused by the friction of the grinder 24, 25 on the collector lamellas, so that this dust does not can advance to a ball bearing 33, which on the shaft 32 opposite the collector 23, with respect to the Magnet 29, is attached. The outer ring of this bearing 33 is in a cylindrical extension 34 of a End flange 35 added, which can consist of metal or plastic) material and has outer edges 36 and 37, which are attached to the ends of the housing elements 16 and 1 '.

-δι The magnet 29 has a central part 29 larger Diameter, which is surrounded by the winding 27, and side parts of smaller diameter, namely 29_, which is supported against the end face of the collector 23 and 29 ,, which against the inner ring of the Bearing 33 is supported. In this way, the magnet 29 forms a strut between the collector 23 and warehouse 33.

In another embodiment, instead of the fingers 50, for fastening the winding 27 to the part 17,

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which protrude from the end face 26 of the part 17, before |! Cracks (not shown) of the wall 52 are provided, which interact with holes (also not shown) which protrude in the end wall 26 _{1 of} the part 17

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are seen. p

The extension 34 is in turn by a further;

Lengthen the cylindrical part 38 of a smaller diameter

gert, which is supported by an elastic ring 39 for suspension $. of the engine is surrounded. Between the cylindrical parts 34 and 38 is a shoulder 40, the one

Forms stop for the outer ring of the bearing 33. ! ■

On the collector 23 with respect to the rotor 20 Opposite side, an inner ring of a further ball bearing 41 is attached to the shaft 32, whose The outer ring is received in an extension 42 of a flange 43, which is formed analogously to the flange 35 is. The cylindrical extension 42 is extended by a further cylindrical part 44 of smaller diameter, which is surrounded by an elastic ring 45, which is designed analogously to the ring 39.

Finally, the end of the shaft 32 on the flange 43 side carries a pulley 46 for the drive the belt of a washing machine.

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In the manufacture of this motor, the rotating and stationary parts are assembled separately.

As for the rotating part, in front of his Assemble with the rest of the motor on the shaft 32 the bearing 33, the magnet 29 of the speedometer generator 28, the collector 23, the rotor 20 with the windings 21, which are connected to the fins 22 of the collector are mounted, the ball bearing 41 and the pulley jQ 4 6. Before assembly is a dynamic balancing made of this rotating part in order to avoid imbalances.

So after the final assembly it is not; very necessary, »Ρ · to carry out a new balancing, because after this assembly no further part is attached to the shaft 32; b ^ in the prior art, however, was the Tachometer generator attached after balancing.

The friction of the grinders 24 and 25 on the larc ^ llen 22 of the collector 23 generates dust, which penetrates to the bearing 33 through the interposition of the wall 52 of the tachometer generator 28 between the collector and this bearing 33 is prevented. The fixed winding 27 and the rotating magnet 29 thus form screens that keep the dust out of the grinder 24 and 25 is generated. The rotational movement of the magnet 29 also leads to a rejection effect by the

g ₀ dust is pushed outward in the radial direction, whereby the shielding effect is supported.

By dynamically balancing the rotating part of the motor before assembling it with the non-rotating _P- the part is made very easy to manufacture. Further it is achieved that the noise generated during operation of the engine is reduced. Through the arrival

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order of the speedometer generator 28 between the camp 33 and the grinders 24, 25, the service life of the bearing 33 is also increased, and there is a generation of noise avoided that could be caused by a dirty or worn bearing.

Claims (7)

PRINZ, LEISE-R ;; BLINKE & -RARTNER patent attorneys, · *; · Euröpf-terC tPat ^ U 'Attorneys Munich Stuttgart February 27, 1985 SOCIETE ELECTROMECANIQUE DU NIVERNAIS SELNI 166, rue des Grands Champs 58000 Nevers / France Our reference: S 3246 Protection claims 1. Electric motor with a collector (23) whose lamellae (22) are in contact with sliders (24, 25), and with a shaft (32) which is in a bearing (33) in the j is stored near the collector (23), as well as with a Tachometer generator which is arranged between the collector (23) and the bearing (33) and whose rotor (29) is fastened to the motor shaft, characterized in that f, a side wall (52) of the non-rotating part (27) ί of the speedometer generator (28) opposite the circumference (54) 10 of the collector (23) is arranged and a protection ί screen that prevents dust from penetrating through ji, the friction of the grinder on the collector lamellas Γ testifies to the camp prevented. 2. Electric motor according to claim 1, characterized in that; that the tachometer generator (28) has a magnet (29), which is mounted on the shaft (32) between the bearing (33) and the collector (23) and of a non-rotating one Winding (27) is surrounded. HD / kn -2- 3. Electric motor according to claim 1 or 2, characterized in that the non-rotating part (27) of the Tachometer generator is firmly connected to a part (17) which is firmly connected to a side wall (14) of the stator (12) is connected and preferably carries the grinder (24, 25). 4. Electric motor according to claim 3, characterized in that that said part (17,) has an end wall (26.,) a. I. , Q tz ^m AEGT having axially directed and elastic in the radial direction of finger (50) disposed between the end wall (26 ..) and respectively the hook (51) to set the non-rotating part (27) edges of these fingers. , j- 5. Electric motor according to claim 3, characterized in that that said side wall (52) of the non-rotating part (27) of the tachometer generator has projections which cooperate with holes in the end wall (26-) of said part (17). 6. Electric motor according to claim 2, characterized in that the magnet (29) of the tachometer generator (28) forms a strut which separates the collector (23) from the bearing (33). 7. Electric motor according to claim 6, characterized in that the magnet (29) has a central part (29) of larger diameter, which is surrounded by the non-rotating winding (27), and lateral parts (29, ² ^ ₃ ) has a smaller diameter.