DE10253570A1 - External vibrator with unbalanced weight and weight fixture constructed so centre of gravity of weight can be adjusted in radial direction, to be used in machine for loosening, compacting, or cleaning - Google Patents

Abstract

Outer vibrator is attachable to mechanism to be actuated by external vibrations. It contains rotary, motor driven shaft (1) with inserted unbalanced weight (2), coupled non-rotatably to shaft by releasable fastener. Unbalanced weight and its fastener to shaft are so designed that gravity centre of unbalanced weight is displaceable radially, pref. using adjustable displacement mechanism. Unbalanced weight contains shaft retainer (3), while weight motion is limited by radial path limiter(s) (5).

Description

The invention relates to an external vibrator for attachment at one over an external vibration device to be excited, with a housing and at least one in the housing rotatably mounted and motor-driven shaft with at least an attached unbalance weight that via a detachable attachment with adjustable Unbalance is rotatably connected to the shaft.

External vibrators of this type are common known. You will e.g. with a speed of 3000 revolutions to loosen, loosen, compress or clean used in screening technology. With speeds from e.g. 1500 revolutions per minute they are used for conveying or Drain in conveyor technology used. High frequency external vibrators that at a speed of e.g. 6000 revolutions are operated, e.g. used for compacting concrete in the construction industry. These external vibrators point essentially one or more waves on which one or several unbalances are attached, which are caused by rotation of the shaft causes the eccentrically arranged center of gravity to vibrate. The system can be vibrated by an elastic mounting Effect of the external vibrator reinforced become.

The known simple external vibrators have a variably adjustable unbalance to the working moment to be able to adjust continuously. Corresponding the setting then turns at a certain speed desired Waveform on. about An upstream electronic control unit can control the speed of the vibrator become.

With the known external vibrators the unbalance is produced by using an electric motor as the basic unit is used, the rotor shaft has a free end on which the unbalance disks are placed. These unbalance disks have e.g. a circular segment-shaped cross section , usually using several unbalance disks at once that are arranged side by side. Usually both ends of the shaft identically equipped with unbalance disks.

It is for the operation of such an external vibrator advantageous to be able to adjust the unbalance to suit the application. For this the unbalance disks are adjusted against each other so that the center of gravity is adjustable.

To implement this setting option the known unbalance disks have a clamp connection. For this the unbalance disks from the axial direction onto the free shaft end the rotor shaft postponed and then over a Screw connection clamped. By loosening the screw connection then the unbalance disc is rotated and then tightened the clamping screw can be fixed on the shaft so that it cannot rotate. The unbalance package so placed on the free shaft end is usually covered by a pot-shaped cover to avoid injury by avoiding the moving parts. This pot-like cover is with the housing screwed on the external vibrator, because very high forces here and frequencies must occur by a sufficient number of Screw connections ensure that the cover cannot detach from the housing.

The cover has in turn been attached now the disadvantage that to adjust the unbalance the cover must be dismantled in order to subsequently the individual panes to be able to adjust. This is relatively high up times connected, which in turn has a negative impact on operating costs.

The object of the invention is therefore an external vibrator create, with little change in manufacturing costs is easy and simple to set with short set-up times.

This object is achieved according to the invention solved by that the unbalance weight and its attachment to the shaft so are trained that the center of gravity of the unbalance weight is radial Direction is displaceable. This is preferably done using a Adjusting device, via the focus is shifted. The adjustment device can either cause a radial displacement of the unbalance weight or due to centrifugal forces or two parts of the unbalance weight in the radial direction relative move to each other.

In a preferred embodiment According to the invention, the unbalance weight has a wave shape a recess open on one side. It is then radial Direction placed on the shaft so that the shaft in the Shaft holder is arranged radially displaceable. Alternatively, you can also a shape of an elongated hole for chosen the wave recording become.

The unbalance weight indicates this Form of the invention on a first through hole through which a limiting emigration due to radial displaceability Radial path limiter is inserted on its shaft side End with a first restraint supported on the shaft and at its weight-side end opposite the shaft-side end with a second restraint, which is based on the unbalance weight is provided.

Due to the inventive design of the external vibrator, the unbalance weights can now be adjusted with little effort. The shaft receptacle is preferably U-shaped, so that the unbalance weight can be attached to the side of the shaft. As with the already known external vibrator, the shaft is preferably a rotor shaft of an electric motor that drives the external electromotive drive guaranteed vibrator. This shaft is led out of the actual motor area so that the unbalance weights can be attached to the free end or the free ends.

The free end is for securing against unintentional touch covered with a pot-like lid that is screwed to the housing. This detail is also natural only optional and essentially does not differ from that known external vibrators. This pot-like cover now preferably has a slot-like opening, via which the adjusting screws for adjusting the unbalance weights can be reached are. Through these openings the operator saves having to dismantle the cover and the openings can with simple snap locks, Plastic caps or two housing parts that can be rotated against each other be completed.

The unbalance weight is over the Radial travel limiter held on the shaft. For this purpose, the radial travel limiter protruding on its side facing away from the shaft End of the first restraint that counteracts the centrifugal force of the rotating unbalance weight and thus prevents slipping off the radial travel limiter. The Radial path limiter in turn is via the second restraint held on the shaft, the second retaining means on the unbalanced weight opposite side can reach behind the shaft or in shape there may be a fixed connection to the shaft. For example the radial travel limiter can be formed by a bolt which is connected to the Shaft is welded.

In a particularly preferred embodiment the invention has not only the unbalance weight of the first through hole on, but there is also a second through hole in the shaft, the radial path limiter then passing through the first and second Through hole is inserted. Alternatively, it can also be in the through hole on the shaft side is screwed in so that the through hole arranged in the shaft is a threaded hole, into which the radial path limiter, which is then preferably cylindrical, is formed is screwed in.

The first through hole in the unbalance weight and the second through hole in the shaft are concentric arranged to each other so that the radial travel limiter through both Can be inserted through holes. In the usual configurations the invention will have at least two imbalance weights. These are opposite to each other arranged on two free ends of the shaft, each of course the shaft ends can also carry several unbalance weights. Necessary and therefore preferred is only one weight per side because of the invention the unbalance already adjustable on the weight itself is and the twisting of individual weights relative to each other is eliminated can.

As an alternative to the second through holes you can also put a ring on the shaft, which then with the radial path limiter is connected. For example, a pleuelstangenähnlicher Attachment ring can be used, which is pushed onto the free shaft end and then over a Clamp connection is attached. Since the setting of the unbalance according to the invention on the Setting the radial distance of the center of gravity of the unbalance weight to the shaft, this clamp connection must be used to adjust the unbalance and then the vibration behavior can no longer be solved.

The radial path limiter preferably has a thread at its rear end into which the first restraint means can be screwed in to limit the unbalance weight. In a particularly simple embodiment, this thread can be a external thread so that a hexagon screw is simply screwed onto the radial travel limiter can be. So that this screw is not accidentally during the Operation solved an anti-rotation device is preferably provided, which prevents rotation the screw prevents.

When using a hexagon nut as the first restraint this protection against rotation can be achieved very simply by that the unbalance weight in the area of this mother's contact surface is a two-sided one Has recess with parallel, opposite edges, into which the nut can just be inserted, but not twisted is. Alternatively, the shape of a hexagon can also be selected, so that the nut with the entire contour can be inserted into the recess. Due to the centrifugal force, the unbalance weight is now against the mother pressed the anti-rotation device will be effective even if the hexagon nut is not aligned with the recess. Twisted namely at this moment the mother around due to the vibration behavior a few degrees, the position in which the Recess and the mother are congruent with each other and the mother snaps into the recess due to the sliding outwards Circulation weight. A further twist is then excluded.

Because of the thickness of the mother however to the outside displacing unbalance weight can, however, affect the vibration behavior of the external jogger changed become. A further preferred embodiment therefore uses one Compression spring, for example as a coil spring around the cylindrical Radial path limiter is wound around. This compression spring pushes that Unbalance weight to the outside, so after setting the one you want Radial distance the nut can be rotated until the hexagonal recess with the hexagonal shape of the nut congruent is.

The spring force then ensures that the unbalance weight is pushed outwards when the nut clicks into place. So there is none during the Necessary rotation of the nut with unpredictable engagement time required. Alternatively, with a simpler design, too the nut and the front face of the radial travel limiter be marked so that the hiring staff the nut can twist so that when the unbalance weight is pushed outwards can snap into the recess.

Particularly inexpensive to manufacture is the radial path limiter, even if the second through hole is used in the wave. In this case it can be used as a radial travel limiter a simple standard screw can be used that is inexpensive as Bulk product available is. This standard screw can be an external and an internal hex screw, it is only essential that it has a thickened head area, the thread-side edge acts as a second restraint. alternative can also use a simple set screw as a radial path limiter on which a hexagon nut is the first or second restraint is screwed on.

Generally can be used as a radial path limiter any form of grub screw or screw can be used both internal and external threads can be used. The radial travel limiter can be inserted into the through hole on the shaft side be screwed in or inserted through them. On Sides of the unbalance weight could an internal thread can also be provided, into which the radial travel limiter is screwed in.

With this configuration then Of course the adjustment on the opposite Side, i.e. then would have to the second through hole penetrate the shaft, the radial travel limiter with a cylindrical rear thread this second through hole also enforce and the second restraint from one the one opposite the unbalance weight Be screwed on at the end. An anti-rotation device could also be used here realized by flattening the shaft in some areas become. After assembling the components, one of the two connections could also be made between either the radial travel limiter and the unbalance weight or between the radial travel limiter and the shaft, for example spot welding become.

The unbalance weight is preferred a segment of a circle Cross-section, with semi-circular cross-sections or circular segments preferred here are going to be between 90 ° and 270 °. The side edges of these circle segments can parallel to the radii of the corresponding circle, but it can other contours can also be used. Especially since the inner areas have less influence on the shift of the focus than the outer areas, one could seen from the shaft radially enlarged segment are used.

The outer radial surface of the Imbalance weight preferably has a circular curvature. In this way the space between the pot-like housing cover can be most effective be exploited. additionally offers this round outer contour some security for the case that, contrary to expectations, an unbalance weight moves away from the radial travel limiter triggers, about due to an assembly error, because in this case the unbalance weight with a surface contact the inner surface the pot-like cover lies and are dragged along so grinding can.

The axial position of the unbalance weights can can be defined either by a clamp connection or by the through hole in the shaft, if provided should be. In these cases are no further measures necessary. In contrast, is the unbalance weight on a radial travel limiter attached, which can be moved radially, for example via a tongue and groove connection is connected to the shaft, so can between a motor Shaft shoulder and the inner unbalance weight a compression spring arranged against the outside of the package formed by the unbalance weights an end abutment presses.

Other features and advantages of Invention result from the dependent claims and from the following Description of preferred embodiments based on the drawings.

In the drawings:

1 a side view of the shaft with the unbalance weight attached,

2 the wave out 1 in a bottom view,

3 the in the 1 and 2 shown shaft in a side view and

4 a 3-dimensional representation of the in the 1 to 3 represented wave.

In the 1 to 4 is a possible design of the shaft 1 with unbalance weight attached to it 2 shown.

The unbalance weight 2 has a semicircular cross section and is with a U-shaped shaft mount 3 provided, which has an offset center to the cross section of the shaft. In this wave shot 3 can the wave 1 are used and over the radial travel limiter 5 be set in the radial direction. Basically, the unbalance weight 2 on the wave 1 slidably supported, the radial travel limiter 5 only limits the maximum displacement.

The unbalance weight 2 is with a first through opening 4 provided by the radial path limiter here cylindrical 5 ge through is stuck. On that of the shaft 1 opposite end forms a simple hexagon nut, which on the externally threaded rear area of the radial travel limiter 5 is screwed on, a first restraint 6 for the unbalance weight 2 , To form an anti-rotation device, the unbalance weight 2 has a hexagonal receptacle in the area of the hexagon nut, into which the nut is inserted when the unbalance weight 2 is pushed outwards due to the centrifugal force.

The first restraint 6 the wave is opposite 1 with a second through hole 8th provided, also through the radial path limiter 5 is stuck through. In the exemplary embodiment shown, the radial travel limiter is formed by a simple standard screw, shown here as an Allen screw.

To form a second restraint 7 has the second through hole 8th a paragraph on which the screw head of the standard screw can be supported. With this connection too, the radial travel limiter could be rotated, for example by a tongue and groove connection 5 be prevented. Alternatively, after inserting the standard screw, a small welding spot can ensure that the standard screw is firmly attached to the shaft 1 connected is.

1

wave

2

unbalanced weight

3

shaft mount

4

Through Hole

5

Radialwegbegrenzer

6

Retention means

7

second Retention means

8th

second Through Hole

Claims (19)

External vibrator for attachment to a device to be excited by an external vibration, with a housing and at least one motor-driven shaft rotatably mounted in the housing ( 1 ) with at least one imbalance weight ( 2 ) that a releasable attachment with adjustable unbalance rotates with the shaft ( 1 ), characterized in that the unbalance weight ( 2 ) and its attachment to the shaft ( 1 ) are designed such that the center of gravity of the unbalance weight ( 2 ) can be moved in the radial direction. External vibrator after Claim 1, characterized in that the location of the focus on a adjustable adjustment device adjustable from the radial direction is. External vibrator according to claim 2, characterized in that the unbalance weight ( 2 ) a wave shot ( 3 ) and the shaft ( 1 ) radially displaceable in the shaft holder ( 3 ) is arranged, the radial mobility of the unbalance weight ( 2 ) via a radial path limiter ( 5 ) is limited, which at its shaft-side end is supported by a first restraining means supported on the shaft ( 6 ) and at its weight-side end opposite the shaft-side end with an unbalance weight ( 2 ) supporting second restraint ( 7 ) is provided. External vibrator according to claim 3, characterized in that the shaft holder ( 3 ) is a recess which is open on one side and in particular has a semicircular end region into which the shaft ( 3 ) is inserted. External vibrator according to claim 2 in conjunction with claim 3 or 4, characterized in that the adjusting device is designed such that the distance between the first retaining means ( 6 ) and the second restraint ( 7 ) is adjustable. External vibrator according to one of the preceding claims, characterized in that the shaft ( 1 ) to the first through hole ( 4 ) concentric second through hole ( 8th ) and the radial travel limiter ( 5 ) the first through hole ( 4 ) and the second through hole ( 8th ) enforced. External vibrator according to one of the preceding claims, characterized in that the radial travel limiter ( 5 ) is formed by a cylindrical rod which is in the area of the first restraint ( 6 ) is threaded onto the first restraint ( 6 ) is screwed on. External vibrator according to the preceding claim, characterized in that the first retaining means ( 6 ) is a hexagon nut. External vibrator according to one of claims 1 to 6, characterized in that the radial travel limiter ( 5 ) is formed by a cylindrical rod, which in the area of the second restraint means ( 7 ) is threaded onto the second restraint ( 7 ) is screwed on. External vibrator according to the preceding claim, characterized in that the second retaining means ( 7 ) is a hexagon nut. External vibrator according to one of claims 7 to 10, characterized in that the radial travel limiter ( 6 ) is formed by a commercially available screw. External vibrator according to one of claims 7 to 10, characterized in that the radial travel limiter ( 6 ) has a screw lock against unintentional loosening in the area of the screw connection. External vibrator according to one of the preceding claims, characterized in that the radial path limiter ( 6 ) at its shaft-side end firmly with the first through hole ( 4 ) connected is. External vibrator according to one of the preceding claims, characterized in that the radial path limiter ( 6 ) at its weight-side end firmly with the second through hole ( 8th ) connected is. External vibrator according to one of the preceding claims, characterized in that the unbalance weight ( 2 ) has a circular segment-shaped cross section and the shaft holder is arranged concentrically with the circular segment. External vibrator according to the preceding claim, characterized in that the unbalance weight ( 2 ) has a semicircular cross section. External vibrator according to one of the preceding claims, characterized in that it has a plurality of unbalance weights arranged next to one another ( 2 ) having. External vibrator according to one of the preceding claims, characterized in that the shaft ( 1 ) is driven by an electric motor arranged in the housing, the shaft ( 1 ) is the rotor shaft of the electric motor. External vibrator according to one of the preceding claims, characterized in that it has two shafts ( 1 ), which are driven by an electric motor, whereby to drive both shafts ( 1 ) a power transmission is provided.