DE8403634U1 - Drive device for a vibration device - Google Patents

Description

Drive device for a vibration device

10

The innovation relates to a drive device for a vibration device, especially a small household appliance, like dry shaver or massage machine, where the Rotor shaft of a rotary drive motor, in particular a single-phase synchronous motor, a Neeken defalcation roller gear, which drives the motor's rotary motion into one Converts vibratory movement, in the case of the cam scanning scanning rollers at a drive end of a pivot arm that can be tilted about a central area and a pivot arm that is to be moved Vibration part are arranged at the output end of the swing arm.

20th

From DE-OS 25 13 007 a starting aid device for a single-phase synchronous motor is known in which pressure rollers are pressed against one cam from opposite directions, which press rollers on slides against one another and can be moved away from each other * This device is an additional starting aid and has with the actual operation nothing to do * The cam is opened after de-energizing by means of the spring-loaded pressure rollers of the stator, even with high friction values, turn the rotor of a single-phase synchronous motor so that it always starts is guaranteed or, in other words, that the main magnetization direction of the rotor is rotated from the main stator field direction so that both directions one

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2 PHD 84-024

Include angles with each other. If both directions of magnetization were to coincide, then the Motor not possible.

Aue of EP-OS 45 107 it is for vibration dry shavers known «to drive these with the help of rotary motors. There are two perpendicular to each other on the rotor shaft Arranged cam disks, each of which is scanned by a roller and which via a lifting joint system Drive the lower blade of the dry shaver. This lever hinge system is vulnerable because it involves film hinges is formed between the individual joint parts. Two cams arranged one above the other on the motor shaft also increase the overall height / what the desire for one as flat a device as possible. In another training with a rotating motor and a Crank drive causes annoying noises.

From EP-OS 45 107 a cam mechanism is also known in which the cam has the shape of an equilateral triangle with three sides curved in the same convex manner, the oscillating movement being picked up on the circumference of the f) cam. The acceptance takes place with the help a U-shaped yoke with parallel legs which enclose the cam on both sides. Has the profile of the cam the property that the distance between any two parallel lines tangent to the profile is constant is. The device is known as a so-called Gieichdick. In this way, when the cam is rotated, the con is within the parallel flanks of the U-shaped yoke The timing of the cam and yoke is constantly maintained. It has been shown that tolerance-

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Problems, clamping and noise considerable difficulties prepare. This also applies to those in US Pat. No. 2,741,132 described arrangement.

Aue of US-PS 27 41 132 it is still known * against a cam by means of a spring to push a roller so as to rotate the cam into an oscillating one Convert movement. To avoid LMrm and vibration, the spring must be made relatively strong, ,, 10 in order to avoid constant contact between roll and cam is lost. On the one hand, this leads to high bearing loads with the risk of premature storage Wear of the mechanical transmission components. On the other hand, there is a significantly higher load torque for the motor due to additional friction and deformations, so that the useful power available on the parts to be driven is significantly smaller will.

It is the task of the innovation, a drive for a Vib ** ationsgerat of the type mentioned, in which the rotating movement of a drive motor in an oscillating ι, movement of a driven vibration part implemented will create * that does not jam, works quietly and. which, compared to known drives, is flat.

According to the innovation, the set task is solved by that two Amäströllen at the same time on the contour of one roll with the rotating cam with the rotor shaft. 30th

In this drive device, the roles alone ensure that contact is maintained between

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4 PHD 84-024

Cams and rollers, as there is a loss of contact with one roller is prevented by the other role.

It is known per se from US-PS 27 41 132, a To let cams revolve between two straight arms in such a way that the rotary movement of a cam in a oscillating movement of the arm assembly is converted. Such an arrangement tends to occur in the case of a Mass production unavoidable tolerances for clamping «The .-, 10 Clamping could be avoided by increasing the Game. However, this would only result in increased vibrations and noise.

Furthermore, the force transmission inevitably occurs at the contact surfaces between the arms IS and the cams

Sliding friction on. In connection with the clamping forces, this leads to frictional moments that are so strong that the drive motor is quickly overloaded. In the case of single-phase synchronous motors, start-up is also endangered · Disadvantageous is also that due to the given geometry with mutually perpendicular arm contact surfaces and a minimum distance between the cam axis and the oscillating! 1-) axis of the cams does not have a certain minimum size can fall below. This minimum size can lead to such a large moment of inertia that the Operation with single-phase synchronous motors is at risk.

The implementation of such a system therefore encounters insurmountable difficulties in practice and is in in the past not even with vibration devices, such as for example dry shavers.

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According to a further embodiment of the innovation it is provided that

- both rollers have the same diameter,

- When the rollers are in the middle, the distance between the two roller axes and the cam axis is the same.

According to a further embodiment of the innovation, the connection between the swivel arm and the axis is one of the both or both roles are designed to be elastic, whereby be-A-10 preferably the oscillation planes of the swivel arm and rollers coincide. This allows running noises to be reduced even further .

According to a further embodiment of the innovation it is provided that in the middle position with an offset angle of ccq = φ = ΐ80 "the connecting lines between the pivot center and the roller center and the connecting lines between the roller center and the cam axis are perpendicular to each other. The pivoting path of the roller center deviates only slightly in this case a linearly oscillating path.

ζ The innovation is explained in more detail using the exemplary embodiment shown in the drawing. Show it:

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Fig. 1 shows the functional view of a vibrator shaver with a rotary drive motor and a cam follower roller gear with a rotating cam and two cam scanning rollers in the middle position.

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Fig. 2a to c three different Nockenatellungen opposite the Abtaet roll in the transmission of Fig * 1 with one

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6 PHD 84-024

elongated, approximately elliptical cams (n = 2), where Fig. 2a shows the system in the middle position, Fig. 2b the left end position and Fig. 2c the right end position,

Fig. 3a to c the transmission according to Fig. 1 with an approximately triangular cam (n = 3) at three different Nocfcunstellen, 3a and 3b middle position, Fig. 3c left end position,

f "\ 10 Fig. 4a to d the transmission according to Fig. 1 with an approximately square cam (n = 4); four different cam positions (a - d) are shown, Fig. 4a and 4d middle position, Fig. 4b left end position , Fig.4c right end position; the cams should otherwise meet the above symmetry conditions.

In the functional view of a Vxbratorrasierapparates 1 shown in Fig. 1 is on a base plate 3 Single-phase synchronous motor 5 attached. The single-phase synchronous motor has a U-shaped laminated core 7 with two legs and 9a. Excitation coils 11 and 11a are pushed onto the legs 9 and 9a. At the free ends of the iron ( kel 9, 9a form pole pieces 13, 13a with formation

a stator bore 15. In the stator bore 15, a permanent magnet rotor 17 rotates on its shaft 19 Cam 21 is arranged. In the illustration according to FIG. 1, the cam 21 has an elongated, approximately elliptical shape Shape·

An axis 23, on which a pivot arm 25 is pivotably mounted, is fastened to the base plate 3. The swivel arm 25 divides into two sub-arms 27, 27a on the drive side

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on. At the free ends of the drive part arms are means Axles 29, 29a mounted on scanning rollers 31, 31a. The follower rollers 31 and 31a feel the contour 33 of the cam 21 by constant concern. At the output end 35 of the lever arm 25 engage drivers 37 of a knife block 39.

In a manner not shown in detail, both drive part arms 27 and 27a or only one of the two can be designed to be elastic ( ^Λ ) 10. It is also possible to make the bearings in the area of the axles 29 and 29a elastic or to provide the outer surface of one or both rollers 31, 31a with an elastic coating in order to bring about a certain compensation to avoid jamming.

15th

In the embodiment according to FIG. 1, the connecting lines close 43 between the motor / cam axis 19 and the roller axes 29, 29a in the center position shown an angle «ο with each other that is 90 *. the right-angled design results with

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25th

for η - 2 and μ - 0 (frequency doubling).

The phase shift depends on the offset angle oco Articulations xi and X2 (Fig.2a). For the invention Function is important to that

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* '** »*' * PHD 84-024 * II * f I • J III3 t »I * 8th xi is always equal to -X2, - 0. where χι = f (oc) and X2 = f (Ct ± öc ₀ ) is. In Figs. 1 and 2a to c is: η = ^: 2 and μ = 90 "one gets: X2 = sin 2 (oc + 90 °) = -sin 2 cc.

Hence X2 = -xi 10

Correspondingly, in Fig. 3a to c: η = 3 and μ = 0.

With xi = sin 3 oc and Ocq = 60 ° one obtains: X2 = sin 3 (oc + 60 ") = -sin 3 oc. 15

Hence X2 = -xi Correspondingly, in Fig. 4a to d: η = 4 and μ - 0

With xi = sin 4 cc and (X o = 45 "we get X2 ■ sin 4 (cc + 45") = -sin 4 «.

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The mentioned dependencies xi and X2 can also be harmonics of higher frequencies than the fundamental frequency included as long as the above-mentioned symmetry condition is met. Since the movement that the rollers 31, 31a from Cam 21 is imposed, originally starting from the central position of the rollers 31, 31a, from a linear oscillating movement in the direction du ;: connecting lines 43 is based on the cam and roller axis, for example

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the center 45 of the pivot axis 23 of the swivel arm is the center of a circle that defines the two roller axes 29, 29a when the rollers 31, 31a are in the middle affects. This circular path should be as close as possible to the originally linearly oscillating roller conveyor. For this purpose, the Sohwenkartnaohee 23 or * the center line 47 of the output parts of the swivel armies the bisecting line 2Wisehen the connecting lines 43 of the roller axle 29, 29a and Wockenachee 19, with the center line 47 runs through Noekenaehse 19 «Bei Mittenetand des Swivel arm 25 should connect lines 41 between the swivel arm axis 23 and roller axes 29, 29a and the Connecting lines 43 between the cam axis 19 and the roller axes 29, 29a are perpendicular to one another Deviations from the linear path lead to distortions. It is possible to take these into account when defining the cam contour and to compensate for them Possibility to come eu a simultaneous uniform abutment of the rollers on the cam is that the Deviations from the ideal linear path in the positive and negative directions are equal. Tolerances and Residual noise can be combated with rollers that are elastic on the whole or on the surface. It is an advantage when one or both drive part arms 27, 27a are elastic and with light pressure for a low Provide contact pressure on the cam 21.

The correct cam contour 33, which meets the above symmetry conditions, is a prerequisite for a Functioning of the drive device. The cam contour can be determined as follows:

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Requirements are ι

1. The roll diameter »Rq

2. The mean distance between the cam axle 19 and roller axles 29, 29a is equal to b.

3. The dependence of the roller deflection on the cam

Rotation χ = f (oe), where the symmetry condition () ¹⁰ «1 * - * 2 must be fulfilled in such a way that the deflection is repeated with the opposite sign after half a period, the dependency thus only containing odd harmonics.

So one draws a circle around the cam axis 19 The radius is equal to the mean distance b from the cam axis 19 and roller sleeves 29, 29a. Above the scope of this In a circle, the positive and negative associated with the respective angles are carried in the radial direction Displacements according to the condition χ = f (Oc). The corresponding radii are around the to the respective angle belonging amount of deflection C. extended or shortened. To get yourself that way The resulting trajectory is drawn in circles in close succession, whose radius is equal to the roller radius. These cut from the original, struck around the nock axis Circle parts out. After the trajectory has been completely circled, the desired cam contour remains. For example the deflection should be sinusoidal from the twist angle depend

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11 PHD 84-024

χ β a sin η α,

where a is the amplitude of the roller deflection that occurs below Consideration that depends on the construction Leverage ratios also determine the amplitude of the oscillating movement of the knife.

The case shown in Fig. 3 with η «3, u« 0 leads to a rotation angle CC ο of the roller axis of 60 ". The case η =» 3, u »1 - not shown in the drawing - leads to an angle with the same cam contour ocq of 180 °. This arrangement with an approximately triangular cam is reminiscent of a Gleichdick drive with a triangular, convexly curved flake The same-thickness contour generally does not have the required symmetry condition, according to which the dependence of the deflection on the rotation only contains odd-numbered harmonics <3 fundamental frequency of the deflection period. In addition, the tangents of the roller drive at the calming points are only parallel in a few positions, and the distance between the contact points of the rollers on the cam circumference 333 is not constant.

It can be seen that if the symmetry condition X2 - -xi is observed, the follower rollers 31, 31a in both cases possible middle positions (Fig. 3a and 3b) of the swivel arm 25 as well as when the swivel arm 25 is deflected from the center line securely on the surface 333 of the triangular Cam 321 are in contact.

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,; In the embodiment according to FIG. 4 with η · 4 and

μ a O results in an approximately quadrangular cam 421. The offset angle <xq of the rollers 31, 31a is then at μ ■ 0 45 °. 4a shows that in this case the lines 41j 5 between the pivot center 45 and the roller center 29 I and the connecting lines 43 between the roller center 29

and cam axis 19 in the middle position of the arrangement perpendicular y are right on each other. The roles 31 «31a are both

? in the middle position of the swivel arm 25 (Figs. 4a and 4d)

&, \ 10 as well as deviating pivot positions (Fig. 4b and 4c) securely to the surface 433 of the quadrangular

ί cam on. The frequency multiplication that can be achieved here

I can be implemented purely mechanically in a very compact design

be f. There are advantages in particular with the

4 IS miniaturization.

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Claims (1)

G 84 04 299.7 PHD 84-024 Philips Patentverwaltung GmbH Protection claims: 1. Drive device for a vibration device, in particular a small household appliance, such as a dry shaver / or massage apparatus, in which the rotor shaft of a Rotary drive motor, in particular a single-phase synchronous motor, a cam-scanning full gear drives, which converts the motor rotary motion into a vibratory motion, in which the cam is scanned Follower rollers at one drive end of a swivel arm that can be tilted around a central area and a closed moving vibration part at the output end of the swivel arm are arranged, characterized in that two scanning rollers (31, 31a) simultaneously on the contour (? 3, 333, 433) of a cam (21, 321, 421) rotating with the rotor shaft. 15th (ι 2. Drive device according to claim 1, characterized in that - both rollers (31, 31a) have the same diameter, - when the rollers (31, 31a) are in the middle, the distance between the two roller axes (29, 29a) and the cam axis (19) is the same size. 3. Drive device according to claims 1 and / or 2, characterized in that at an offset angle the connecting line (41) between the swivel • II i> <iii «Ti» »*> ·">> >> < 14 PHD 84-024 center (45) and roller center (29) and the connecting lines (43) between roller center point (29) and The cam axis (19) are perpendicular to one another. 5 4. Drive device according to claims 1 to 3, characterized characterized in that the connection between the pivot axis (23) and the axis (29, 29a) is one of the two I or both rollers (31, 31a) is designed to be elastic. f (~ \ 10 5. Drive device according to one or more of An-I Proverbs 1 to 4, characterized in that the oscillating ■, level the swivel arm (25) and rollers (31, 31a) together '^; fall. 15 6. Drive device according to claims 1 to 5, I characterized in that the pivot arm (25) on the one side of the pivot axis (23) an output arm (35): for cooperation with a vibrating part (39) and on ', the other side of the pivot axis (23) drive part arms 20 (27, 27a) which can be pivoted with respect to the output arm (35) and are spring-tensioned towards one another. 25th 30th 35 Il I I I · I