FR2494732A1 - ENGINE AND TRANSMISSION MECHANISM FOR WASHING MACHINE - Google Patents

Abstract

THIS WASHING MACHINE MECHANISM INCLUDES AN ALTERNATIVE CURRENT MOTOR AND NUMBER OF 7 POLE PERMUTATION, WHICH, THROUGH AN INDUCTION CLUTCH DEVICE 15 AND A BELT 5 TRANSMISSION SYSTEM, DRIVED IN ROTATION DRUM 3 OF THE WASHING MACHINE 1. A PROGRAM CONTROL 11 STARTS THE MOTOR WITH THE LOWER NAME OF POLES (FOR EXAMPLE 2) FOR THE SPIN CYCLE AND WITH THE HIGHER NUMBER OF POLES (FOR EXAMPLE 12) FOR THE CYCLE WASHING. THE OUTPUT SPEED OF THE CLUTCH DEVICE 15 IS, BOTH IN SPIN AND WASHING RPM, MAINTAINED BY A REGULATION CIRCUIT 17 AT THE PROGRAMMED SET VALUE. THIS CIRCUIT SENDS TO THE CLUTCH DEVICE 15 DIRECT CURRENT PULSES THE RATE OR DURATION OF WHICH ARE A FUNCTION OF THE ACTUAL OUTPUT SPEED FROM THE latter.

Description

The present invention relates to a motor and transmission mechanism for

rotate the drum

  a washing machine operating with at least one speed

  and a spin speed, including a

  electric tor, an induction clutch

  incorporated in the kinematic chain between the electric motor

  that and the drum and a program cycle control of

wash and spin cycle.

  In traditional drum washing machines,

  the drum is rotated at a speed which,

  during the washing cycle, is around 50 rpm, while during the spin cycle it reaches about 1000

  revolutions / minute. This ratio of 1/10 between the speeds of ro-

  respective washing and spinning stations cannot, when

  only one electric motor is provided for the central-

  drum, obtained exclusively by permu-

  number of motor poles. This is why these mo-

  pole swap drives drive the drum through the

  intermediary of a transmission mechanism whose inter-

  vention is controlled by centrifugal force, depending

  the engine speed. The motorcycle-re groups

  conductors of this type cannot, however, entrain the

  bour only at two different speeds, set by the cons-

  tructor. In order for the washing machine to operate with more than one washing speed and more than one spin speed, it is known to use collector motors for driving the drum; electronically adjustable. However, such motor mechanisms consume a lot of current during the washing cycles and, due to the presence of a collector, they are excessively noisy during the spin.

  We also know by the description that is made

  in the German utility model 66 03 904 a

  wash whose drum is, during the wash cycle,

  dragged by a first motor, designed to turn at regi

  peculiar to this cycle, while during the test cycle

  rage, it is driven by a second electric motor, di-

  set to spin at spin speed. To avoid

  ter unnecessary losses of motive power, each of

  these two motors is coupled to the drum by means of

  diary of an electrically controlled clutch device.

  The washing motor clutch is a clutch device.

  traditional age, magnetically actuable, that is, either

  totally engaged, or totally disengaged. That of the mo-

  spin wrench is an induction clutch

  and it is brought into the engaged state according to a program-

  given to me when starting the drum in the spin cycle,

  so that the laundry to be spun can be evenly distributed

lying on the wall of the drum.

  British patent 910,884 and German patent 1,488,483 contain information on mechanisms

  electric motors are the output speed can be mo-

  defined by means of an induction clutch.

  The output speed of the latter is detected by means of a tachometric dynamo. A control regulation circuit

  excitation of the clutch device so that its

  output tesse remains substantially constant, whatever

or the engine load.

  The object of the invention is to provide for a machine

  do to wash a motor mechanism which with a single motor

  electric, allows the drum to be driven at a speed which can be chosen practically at will within the limits

  a very wide speed range. In addition, the per-

  your electrics should be kept as small as possible, especially during the wash cycle, and during the cycle

  the operating noise must be reduced.

  Finally, construction must remain relatively simple.

  To this end, in the motor and trans-

  mission according to the invention, the electric motor is alternating current with pole reversal which the program control starts with a first number of poles in

  spin cycle and with a second number of poles, higher

  first, in the washing cycle, and the

  induction clutch is connected to a regulation circuit

  speed which, by regulating the excitation current of the clutch device, maintains its output speed at the programmed values, both for the spin cycle and for the wash cycle. Thanks to this arrangement, it is possible to use a silent, robust and maintenance-free induction motor, the consumption of which is low,

  both during spinning and washing. This engine is advantageous-

  a single-phase alternating current motor. Opposite-

  traditional motor mechanisms at regular speed

  lée used in washing machines, the decrease in the motor output speed is not obtained in the prig of its heating, because, both in washing and spinning mode, the engine runs at nominal speed fixed by the number of poles. Engine cooling

  is therefore insured. The control current of the emitting device

  induction clutch is very low, so you can

  use inexpensive control circuits.

  All that is required is a permutation of the electric motor

  be two numbers of poles to obtain the necessary speeds

  drums, both washing and spinning. The name-

  the lowest number of poles is such that it allows the highest spin speed to be obtained. The difference between the speeds of the electric motor and whose ratio between the numbers of poles are advantageously between 6/1 and 10/1. To keep the higher number of poles involved in the washing cycle within limits where it is technically feasible in a simple manner, the

  first number of poles, which determines the spin speed

  ge, must be as low as possible. It is advantageous that the lower number of poles is 2, the higher number

  being 12. As with a number of poles equal to 2 the speed-

  motor output is greater than the speed of the drum

  bour which is necessary in the spin cycle, the engine

  electric is connected to the drum via a

  reduction gear, preferably a belt mechanism

  of transmission. The reduction ratio of this met-

  reduction gear is advantageously between 2.5 / 1

and 3.5 / 1.

  The speed control circuit controls the sliding of the clutch by induction between

  values between about 0.85 and almost zero.

  When the drum rotates at the highest spin speed

  high, the excitation of the clutch device by induc-

  tion is total, so that the slip is close to zero.

  During the washing cycle, sliding is understood

be 0.5 and 0.85, approximately.

  The excitation winding of the clutch device

  induction ge is preferably powered by a mounting

  of the speed control circuit in pulses of

  continuous rant, assembly which emits these pulses with a rate or a width of pulse which is a function of the output speed of the clutch device. As the excitation current of the latter is relatively low, we can

  use as excitation pulse trigger assembly

  tion an assembly with a transistor output stage. Com-

  ready for relatively late thyristor phase delay controls

  complex, the complexity of building such a

mounting is reduced.

  In a preferred embodiment, the motor

  alternating current is connected, on the one hand, by the device-

  tif clutch by induction to the drum and, on the other hand, by at least one additional clutch device with permanent magnet to at least one auxiliary device of the

  washing machine, such as the drain pump or a fan

  tor. We therefore use a single motor for the drive

  drum and auxiliary equipment. These

  the latter may, depending on the excitation of the em-

  induction clutch, operate at the same time as the

  drum or when it is stopped.

  An induction clutch device must be able to be manufactured without great expenditure of technical means, that is to say in an economical manner, and it must also have a good yield. A clutch device which fulfills these conditions comprises a pole wheel provided with

  an excitation winding which produces a magnetic field

  axially oriented, as well as an inductor arranged co-

  axially to the wheel and which rotates relative to it. The polar wheel, for its part, carries a cylinder head with a

  disc at each of the two axial ends of the coil-

  exciter, the discs each carrying a plurality of pole pieces distributed around their periphery with intervals between them, each pole piece being in each disc opposite an interval between the pieces

  the other discs. The exciter winding pro-

  then duit between the pole pieces of the magnetic fields

  oriented in the peripheral direction and of alternate polarities

  born. The inductor is preferably shaped as a short-circuit rotor and is formed from a molded piece of metal

  under pressure, which is fitted with two short-circuit rings

  cooked placed at a certain distance from each other in

  the axial direction, coaxial with the polar wheel, and a greater

  of short-circuit strips, distributed over its

  riphery, which extend between the two rings in the axial direction and form with the rings only one piece. The

  angular distance between the bars is preferably equal to-

  equal to that between neighboring pole pieces. One of the short-circuit rings at the same time forms a hub for cantilever mounting of the inductor on the motor shaft or on a separate shaft, linked in rotation to that of the

  engine. An inductor of the type just described

  crit can be made inexpensively. This is particularly

  strictly true when the short-circuit ring which forms the hub forms only one piece with the output pulley

movement.

  To improve the performance of the clutch system

  by induction, the short-circuit bars are covered

  lées in axial grooves of a carcass made of sheet metal

  the soft iron insulated from each other and

stacked in the axial direction.

  In any case, the invention will be well understood at

  using the following description, with reference to the drawing

  schematic appended, showing, by way of nonlimiting example, an embodiment of this motor mechanism: FIG. 1 is a diagram of a drum washing machine and of the motor mechanism according to the invention; Fig. 2 is a side view and half in longitudinal section of an induction clutch device

  for the motor mechanism - of fig. 1.

  We can see in Figure 1 a drum washing machine 1, whose drum 1 rotatably mounted on an axis

  horizontal is driven, both during the

  during the spinning cycle, by a single-phase alternating current motor 7 'to which it is connected by a belt transmission system 5. A program control Il connected to the mains (alternating current> at 9 starts and stops the cycles of washing and spinning the machine

  wash 1 and adjust the speed of rotation of the drum 3

  according to the wash and spin program selected.

  The spin speed is around 1000 revolutions per minute, while the washing speed is only about 50 revolutions / minute. There is therefore a difference between these two speeds which corresponds to a ratio of 20/1. To get

  this difference and to be able to vary the spin speed

  and that of washing as a function of the program formed on the command 11, the alternating current motor 7 is conformed to an induction motor with permutation of number of poles and, between its output shaft 13 and the belt transmission system 5 a clutch device is interposed by

  induction 15, including sliding and, consequently, vi-

  output, are maintained at the set value given by the program control II by means of a regulation circuit 17. The induction clutch device

  includes a pole wheel 19 mounted on the output shaft

  tie of the motor and provided with an excitation winding, wheel which produces in a coaxial inductor 21, able to turn

  relatively to it, eddy currents which communicate

  quent a rotational movement to the inductor 21 linked to the system

  belt transmission teme 5 when the pole wheel

  re 19 is driven by the alternating current motor 7.

  In the embodiment shown, the pole wheel 19 is fixed on the output shaft 13 of the motor. A reverse arrangement, in which the inductor 21 is set on 1 '

  tree 13, is also suitable.

  The sliding of the clutch device by induc-

  tion 15 is a function of the excitation of the pole wheel 19.

  The excitation current is sent by a trigger circuit

  pulse generator 23, which consists of a rectangular pulse generator 25 and an output stage A

  transistor 27. The generator 25 produces pulses rec-

  the output stage 27 sends in the form of direct current pulses to the excitation winding of the pole wheel 19. The width or duration of the pulses

  and if necessary also the pulse rate is controlled

  dice by a comparator stage 29, which compares the signal of

  setpoint given by the program command Il a-

  with an actual value signal, which corresponds to the actual output speed of the clutch device 15 and sends to the

  rectangular pulse generator 25 an er- signal

  which determines the duration and the rate of the impulses.

  The AC motor 7 is designed so that it is possible to swap between two numbers of poles: 2 and 12. For the spin cycle, the program command sends on line 33 a signal which starts the motor with the number of poles 2. For an alternating current of 50 Hz, this gives an output shaft speed 13 of approximately 3000 revolutions / minute. For a maximum spin speed, the command Il sends a setpoint signal which causes total excitation of the clutch device 15. In this case, the slip of the latter, that is to say the ratio of the difference between the input speed and

  that of exit with the speed of entry is close to zero

  ro, which means that the output speed is, it

  also, about 3000 revolutions / minute. The trans-

  belt drive 5 has a gear ratio of about 2.8 / 1, so that it lowers the output speed of the clutch device 15 and rotates the drum at a speed of about 1000 rpm. By increasing the slip of the clutch device, the

spin speed.

  For the washing cycle, the program control 11 starts the alternating current motor 7 with the number of poles 12 by sending a signal on line 35. For a mains frequency of 50 Hz, this gives an output speed d '' around 500 rpm in the case of a synchronous motor, and a reduced speed depending on the slip of the motor when it is asynchronous. For

  total excitation of the clutch device by induc-

  tion 15, the drum 3 would therefore rotate at a speed which doesn’t

  not quite reaches 180 rpm. To bring this-

  rotational speed at the desired washing speed, approx.

  at 50 rpm, control 11 increases the sliding of the available

  clutch clutch 15, bringing it to about 0.7. We can therefore, by modifying this sliding, modify in a large

measures the washing speed.

  The same motor 7 can, via an au-

  be belt transmission system 37, drive a drain pump 39 or another auxiliary device of the

  washing machine 1. The drain pump 39 is advantageous-

  flange mounted on the side of the electric motor 7

  opposite to that where the clutch device is located.

  tre the motor 7 and the pump wheel 39 is interposed a permanent magnet clutch device 41. The latter serves to limit the torque transmitted to the pump, in the case

  o its wheel would be blocked by a foreign body

  ger, present for example in the detergent water to be drained.

  The pump 39 can operate either simultaneously with the drum, or independently of the latter, when, in

  the latter case, the clutch device 15 is not ex-

  cited. Figure 2 shows in detail the construction of an induction clutch device suitable for use in the washing machine described with reference to the figure

  1, the same parts being designated by the same references

  these. On the output shaft 13 of the alternating current motor

  tif and permutation of poles 7 is wedged a hollow shaft 44,

  on which a polar wheel is rotatably mounted

  re 19. This wheel 19 comprises a coil 45 arranged coa-

  xial to the shaft 1, which surrounds a soft iron core 47 in the form of a sleeve. At each axial end of this core 47 is connected a cylinder head disc, respectively

  49, 51, which carries a plurality of pole pieces, respectively

  53 and 55, distributed over its periphery. Each piece

  this polar of each disc extends into the interval-

  the correspondent between two pole pieces close to the other disc. When the coil 45 is supplied with current, magnetic fields are formed between the pole pieces 53, 55 oriented in the peripheral direction of the wheel.

  polar 19, whose polarities alternate.

  Inductor 21 is made from a single piece of die-cast metal. It surrounds the pole wheel 19 and is mounted coaxially with the latter, overhanging on the hollow shaft 44, by means of bearings with

  balls 57. This inductor 21 comprises a plurality of bars

  short circuit 59, which are arranged at intervals

  them on its periphery and form a single piece, on the

  side facing motor 7, with a short-circuit ring

  baked 61 and, on the opposite side, with a hub 63, which also serves as a short circuit ring. The hub 63 maintains the inductor on the hollow shaft 44 by means of the

  ball bearings 57 and it has a trapezoid groove! -

  dale 65 for the belt of the transmission system 5. The short-circuited bars 59 are mounted in axial grooves 67 of an annular carcass 69 constituted by a

  axial stacking of electrically insulated soft iron sheets 71

  relative to each other.

  On the pole wheel 19 are mounted two rings of

  concentric contacts 73, 75, connected to the terminals of the box

  bine 45 and electrically isolated from each other, against

  which rub brushes 77 and 79, respectively.

  These brushes 77, 79 are mounted on an insulating support 81

  secured to the flange adjacent to the motor housing.

  In operation, excitation current pulses are sent to the coil 45 via the brushes 77, 79 and the contact rings 73, 75 and these pulses

  produce between the pole pieces 53, 55 a magnetic field

  tick which turns with the polar wheel 19. This magnetic field

  that induced in the short-circuit bars 59 of the

  eddy rants and thus rotate the inductor 21.

11.

Claims (14)

- CLAIMS -   1.- Motor and transmission mechanism for driving   rotating the drum of a functioning washing machine   with at least a washing speed and a spin speed, comprising an electric motor, an induction clutch device incorporated in the kinematic chain between the electric motor and the drum and an X-control   wash cycle and spin cycle program, charac-   characterized in that the electric motor (7) is an alternating current motor and number of poles swap, which the program control (11) starts with a first number of poles for the spin cycle and with a second   number of poles, greater than the first, for the cycle of the-   vage, and in that the induction clutch device (15) is connected to a speed control circuit (17) which, by regulating the excitation current of the clutch device (15), maintains the speed of output thereof at the programmed values, both for the spin cycle and for that of washing.   2.- Mechanism according to claim 1, characterized in that the ratio between the second and the first number   of poles is chosen between 6/1 and 10/1.   3.- Mechanism according to claim 2, character-   se in that the first number of poles is 2 and in that the second number of poles is 12.   4.- Mechanism according to claim 1, characterized in that the electric motor (7) is connected to the drum (3)   via a transmission system by cour-   goose (5) which has a constant reduction ratio understood between 2.5 / 1 and 3.5 / 1.   5.- Mechanism according to claim 1, characterized   in that the speed regulation circuit (17) modifies   relies on the sliding of the induction clutch   (15) between values of approximately 0.85 and almost zero.   6.- Mechanism according to claim 1, characterized in that the induction clutch device (15) is electrically connected to a pulse trigger assembly   (23) of the regulation circuit (17), which sends to the device   tif clutch of direct current pulses whose rate and duration are a function of the output speed of this last.   - 7-.- Mechanism according to claim 6, characterized in that the pulse trigger assembly (23) comprises   a transistor output stage (27).   8.- Mechanism according to claim 1, characterized   in that the DC motor (7) is connected to the drum   bour (3) by the induction clutch device (15) and at least one auxiliary appliance (39) of the washing machine, in particular a drain pump or a fan, via at least one clutch additional (41) of the permanent magnet type.   9.- Mechanism according to claim 1, characterized   in that the induction clutch device (15) comprises   carries a pole wheel (19) provided with an excitation winding   tation (45) which produces an axially oriented magnetic field   ment, as well as an inductor (21) arranged coaxially with the pole wheel and which rotates relative to it, in that the pole wheel (19) comprises a yoke (47,49,51) with a disc (49,51) at each of the two axial ends   of the exciter winding (45), the discs carrying each   cull a plurality of pole pieces (53,55) arranged at intervals around their periphery, each pole piece being, in each disc, facing an interval between the pole pieces adjacent to the other disc, in that the inductor (21) is formed from a single piece of die-cast metal, provided with two short-circuit rings (61,   63) arranged at a certain axial distance from one another   tre, coaxial with the polar wheel (19), and a plurali-   tee of short-circuit bars (59), distributed on its   periphery, which extend between the two short rings   circuit in the axial direction and do not form with these   only one piece, and in that one of the short rings-   circuit (63) at the same time forms a hub for mounting   o-false carrier of the inductor (21).   10.- Mechanism according to claim 9, characterized in that the short-circuit bars (59) are cast in axial grooves (67) of a carcass (69) formed of annular sheets of soft iron (71) electrically insulated relative to each other and stacked in the direction axial of the inductor.   11.- Mechanism according to claim 9, characterized in that the short-circuit ring (63) which forms a hub forms only one piece with an output pulley movement (65).   12.- Mechanism according to claim 9, characterized   in that the pole wheel (19) and the inductor (21) are   lées on a common shaft (44) integral in rotation with the output shaft (13) of the AC motor (7).   13.- Mechanism according to claim 12, character-   in that the common shaft is a hollow shaft threaded on the output shaft of the engine and integral in rotation with this tree.   14.- Mechanism according to claim 1, characterized in that the alternating current motor (7) is a single phase motor.