Kit for Rammers with Different Drive Types

Abstract

A rammer kit for soil compaction rammers with different drive types includes a crankcase for receiving a crank driving mechanism for converting a rotary drive motion generated by a drive into an oscillating translational motion. The crankcase has a connection opening to which a drive cover can be connected. The drive is attached to the drive cover. Different drive covers are provided as part of the kit for drives of different drive types, while the crankcase is identical for drives of different drive types.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a rammer kit for soil compaction rammers with different drive types.

2. Description of the Related Art

Soil compaction rammers are often also referred to as vibration or vibratory rammers and have a rotating drive, for example an internal combustion engine or an electric motor, which drives a spring ramming system with a crank driving mechanism and a spring system. Usually, a rammer has an upper mass, which is essentially formed by the motor and for example the crank driving mechanism and other components, and a lower mass, which is coupled to the upper mass via the spring ramming system and can be moved back and forth relative to the upper mass, comprising a ground contact plate or a ramming foot. The upper mass and the lower mass may for example also be additionally connected by a bellows, which allows the components to move in relation to one another and protects the interior, in particular the crank driving mechanism and the spring system, from the ingress of dust and dirt.

A guiding device, such as a guiding bar, may be mounted on the upper mass for an operator to guide the rammer. It is possible here to provide a vibration decoupling device, for example in the form of rubber elements, between the upper mass and the guiding handle, so that the strong vibrations occurring at the upper mass are not introduced directly into the hands and arms of the operator.

Such rammers are typically operated here by means of a rotating drive via a crank driving mechanism, a connecting rod and a double-acting spring ramming system. Provided for this purpose in the spring ramming system is a piston which can be moved back and forth by the connecting rod and against both sides of which, i.e. in particular above and below, there respectively lies a spring assembly.

The crank driving mechanism is enclosed here at the upper mass by a crankcase, to which the drive is also attached.

Such a rammer is known from DE 10 2021 116 244 A1.

In the past, vibratory rammers were often driven by internal combustion engines, for example diesel or two-stroke or four-stroke petrol engines. Increasingly, however, the drives are being electrified. Modern battery technologies in particular make it possible also to drive vibration rammers by powerful electric drives.

On the manufacturer's side, a separate crankcase with a suitable motor flange must be provided for each rammer or drive type. The motor (drive) respectively provided can be attached to the motor flange of the crankcase. Due to the variety of drive options and the resulting crankcases, manufacturers are facing an increasingly greater logistical effort. This means that many different components must be stored and fed to the assembly line. Assembling the components on known crankcases is sometimes laborious and inefficient.

SUMMARY OF THE INVENTION

The invention is based on the object of countering the increasing number of different components in the assembly of vibration rammers and reducing the number of components.

The object is achieved by a rammer kit for soil compaction rammers with different drive types. The rammer kit includes a crankcase for receiving a crank driving mechanism for converting a rotary drive motion generated by a drive into an oscillating translational motion. The crankcase has a connection opening to which a drive cover can be connected. The drive is attached to the drive cover. Different drive covers are provided as part of the kit for drives of different drive types, while the crankcase is identical for drives of different drive types.

While, in the prior art, different crankcases are therefore also necessary for receiving the crank driving mechanism for different drive types, according to the invention uniform or identical crankcases can be used. It can be that just the drive covers that cover the connection opening on the crankcase for connecting the drive vary.

The crank driving mechanism arranged in the interior of the crankcase may have, in particular, a crank pin or crank cam, via which a connecting rod can be driven, via which the oscillatory translational movement that can be generated thereby can be generated as a working movement.

The different drive types include different motor types, with which respectively the rammer can be driven. Regarded as the system limit for a drive or motor is the motor shaft, to which further components can subsequently be connected.

According to the basic concept of the kit or modular system, according to the invention different rammer versions can thus be set up and assembled with always the same crankcase. The kit therefore has a single type of crankcase and several drive covers which can be assembled on the crankcase and to which for their part a drive can be attached.

The drive covers which can be attached to the crankcase may be standardized and equipped with different drives. In this context, standardized means that the connection flange of the drive cover to be attached to the crankcase can be standardized, that is to say made uniform, while further areas of the drive cover can be configured and customized or adapted to the drive depending on the drive to be assembled on it.

This makes modular drive mounting possible. In particular, the drive can be pre-assembled with the drive cover as a module before the drive and drive cover are attached together to the crankcase of the rammer. In this way, the drives can already be completely set up on the drive cover beforehand. The drive cover is then placed on the crankcase together with the completely assembled drive and attached.

The drive cover completes and closes the crankcase, so that the interior of the crankcase is protected against the ingress of dust and dirt.

When the drive is completely attached to the drive cover, the drive cover supports the drive.

The further setup of the rammer may be known, per se, from the prior art. Thus, the rammer may have an upper mass and a lower mass, which can be moved relative to the upper mass, wherein the lower mass may have a ramming foot with a ground contact plate for soil compaction, the crankcase may be part of the upper mass and wherein the crank driving mechanism may be designed to move the ramming foot back and forth.

The drive cover may be completely pre-assemblable, such that the drive is completely set up on the drive cover before the drive cover is placed on the crankcase.

The drive types may be selected from the group consisting of:

• • an internal combustion engine;
  • an electric motor in which a drive torque of the electric motor is transmitted to the crank driving mechanism via a gear mechanism;
  • an electric motor that is designed as a direct drive. In this case, a rotor of the motor may be formed on a motor shaft which transmits the drive torque directly to the crank driving mechanism without a further gear mechanism in between;
  • an electric motor that is formed as a segmented motor. In this case, the motor may have a rotor and a (possibly segmented) stator surrounding the rotor over a segment of a circle with an angle of less than 360 degrees;

Petrol engines, specifically two-stroke or four-stroke engines, as well as diesel engines, are suitable as internal combustion engines.

In addition to the aforementioned gear mechanism, a clutch, such as a clutch bell, may also be arranged between the engine and the crank driving mechanism. The clutch bell has a centrifugal clutch that opens or closes the clutch depending on the speed and thus allows or does not allow a torque flow. It is possible here to set a limiting speed above which the clutch closes, so that the drive torque can drive the crank driving mechanism.

The types of electric motors may be differently designed. For instance, in one variant an electric motor may directly replace an internal combustion engine without any further structural modifications in the drive area, the drive torque of the electric motor being transmitted to the crank driving mechanism via a gear mechanism.

In another variant, the electric motor is designed as a direct drive. The drive torque is in this case transmitted from the motor shaft of the electric motor to the crank driving mechanism directly, without a further gear mechanism, for example a toothed gear mechanism, in between. The crank driving mechanism can then for example be coupled directly to the rotor of the electric motor.

A special embodiment of the electric motor may be the segmented motor in which a (possibly segmented) stator surrounds the rotor over a segment of a circle with an angle of less than 360°. Here, too, the rotor forms the motor shaft directly and can be coupled directly to the crank driving mechanism. In particular, the rotor can also directly support the crank pin, which serves for driving the connecting rod.

A connection flange may be provided at the connection opening of the crankcase, wherein the different drive covers respectively have a connection flange adapted to the connection flange of the crankcase and wherein the connection flanges of the different drive covers are identical to one another. Relevant here for the identity of the connection flanges is an identical flange pattern with an identical arrangement of the bolts and possibly sealing profiles.

The drive respectively assigned to a drive cover may be attached directly on one side of the drive cover. This means that the motor may be attached to and supported by the drive cover directly on the inside or outside. Internal combustion engines are usually always attached here on the outside, while in the case of electric motors it can be chosen, depending on the type, whether they are to be attached on the outside or inside (and thus inside the crankcase). The drive or the motor may be bolted directly to the drive cover or attached by a suitable bracket.

The crank driving mechanism may have a crank pin rotationally driven by the drive. Different types of design can be implemented for torque transmission between the motor shaft or the rotor of the drive and the crank pin. The crank pin may thus be arranged directly on the rotor of the electric motor, as is the case for example with a direct drive or segmented motor.

In one variant, a gear stage may be provided between the motor shaft and the crank pin, with the crank pin itself being mounted on a gear wheel. In another variant, a clutch bell which allows the torque flow to be interrupted at low motor speed may also be provided between the motor shaft and the gear stage. Only when the motor is brought up to a higher speed does the clutch close, so that the gear mechanism and thus the crank pin are rotationally driven.

As already explained, the drive may have an electric segmented motor, wherein the segmented motor has a rotor and a segmented stator, which encloses the rotor not over the entire circumference but only over a segment of a circle. Here, the angle of the segment of a circle is below 360°, for example less than or equal to 180°, less than or equal to 120° or less than or equal to 90°.

The segmented motor can particularly advantageously be assembled on the drive cover. For this purpose, a bearing pin may be provided or formed on an inner side of the drive cover, for rotatably supporting or bearing the rotor, wherein the segmented stator may then also be held on the inner side of the drive cover.

In one particular embodiment, at least two grooved recesses may be formed on the inner side of the drive cover, wherein the segmented stator, seen in its circumferential direction, may have two end-face ends, wherein a cam which can be pushed into the respectively assigned grooved recess may be respectively formed at the two end-face ends of the segmented stator, and wherein the respective pairings comprising a cam and a grooved recess at the two end-face ends of the segmented stator form stator brackets which are arranged in the circumferential direction of the segmented stator.

In this case, the ends of the segmented stator are arranged at the end faces, seen in the circumferential or main direction of extent of the segmented stator. The stator brackets or pairings serve primarily for centering the stator on the drive cover. This allows the rotor and the stator to be conveniently pre-assembled on the drive cover before the complete unit, consisting of the drive cover and the segmented motor, is attached to the remaining rammer or its crankcase.

The stator brackets are arranged in the circumferential direction of the segmented stator and can in this way support the drive torque well.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other advantages and features of the invention are explained in more detail below on the basis of examples with the help of the accompanying figures, in which:

FIG. 1 shows in a schematic perspective view an example of a soil compaction rammer according to the invention;

FIG. 2 shows in a schematic representation different variants of rammers with different drive types;

FIG. 3 shows some of the variants of FIG. 2 in a more detailed representation; and

FIG. 4 shows an example of a drive cover for a segmented motor, with a pre-assembled segmented stator.

DETAILED DESCRIPTION

FIG. 1 shows an example of a rammer according to the invention.

The rammer has an upper mass 1 and a lower mass 2, which can be moved relative to the upper mass 1. A guiding bar is mounted on the upper mass 1 as a guiding handle 3 for an operator. For the connection and vibration decoupling between the upper mass 1 and the guiding handle 3, vibration decoupling elements in the form of rubber buffers 4 are arranged in a manner known per se.

A component part of the upper mass 1 is also a drive motor 5, which may be designed as an internal combustion engine or an electric motor, as will be explained in detail later.

In the example shown in FIG. 1, the drive motor 5 rotationally drives a crank disk 7 via a gear mechanism 6, which may for example have a pinion. The crank disk 7 accordingly bears an external toothing. Coupled to the crank disk 7 via a crank pin 9 is a connecting rod 8, whereby a crank-swivel joint is formed.

The crank driving mechanism formed by the crank disk 7 and the crank pin 9 is housed in a crankcase 10. An outer guide tube 11 extends on its underside.

The lower mass has a ramming foot 12 with a ground contact plate 13 and an inner guide tube 14 extending upward from the ground contact plate 13. The inner guide tube 14 of the lower mass 2 can be moved axially back and forth in the outer guide tube 11 of the upper mass 1.

The crankcase 10 is connected to the ramming foot 12 via a bellows 15 in order to protect the components provided there from dirt, dust and moisture.

Arranged inside the inner guide tube 14 is a piston 16, which is movably connected to the connecting rod 8 via a rotary joint 17.

Respectively arranged above and below the piston 16 is a spring assembly, specifically an upper spring assembly 18 and a lower spring assembly 19. The two spring assemblies 18, 19 are thus connected to the piston 16 with one side of the respective springs. With the other, opposite side, each spring assembly 18, 19 lies against an end-side end of the inner guide tube 14. In this way, the movement of the piston 16 enforced by the movement of the connecting rod 8 can be transmitted vibratingly via the two spring assemblies 18, 19 to the ramming foot 12 in a manner known per se.

The setup of such a rammer is known to this extent.

It can be used uniformly for rammers with different drive types. It is thus possible to use motors of different types of design for the drive motor 5, as will be explained later on the basis of FIGS. 2 to 4.

The drive motor 5 is supported by a drive cover 20, on which in the example shown the gear mechanism 6 and the crank disk 7 with the crank pin 9 are also attached or rotatably mounted. In an assembled form, the drive cover 20 forms part of the crankcase 10 and closes a rear connection opening of the crankcase 10.

FIG. 2 shows examples of rammers with different drive types in a schematic representation.

Variant A relates to a so-called direct drive, in which the drive motor 5 is attached to the drive cover 20 on the inner side, so that all components of the drive motor 5 are arranged inside the crankcase 10. The direct drive may be advantageously formed by a segmented motor, which is further explained later on the basis of FIGS. 3 and 4.

In variant B, the drive motor 5 is designed as an interior electric motor that drives the gear mechanism 6.

In variant C, the drive motor 5 is implemented as an exterior electric motor and drives the gear mechanism 6.

Variant D shows a two-stroke petrol engine with an exterior internal combustion engine as the drive motor 5, which drives the interior gear mechanism 6.

In variant E, a four-stroke engine is provided as the drive motor 5, in variant F a diesel engine.

In FIG. 3, the variants of FIG. 2 are shown in more detail.

Variant A of FIG. 2 corresponds to variant A of FIG. 3. Schematically shown here is the drive cover 20, which has a segmented stator 21 on its inner side and a rotor 22 rotatably mounted on the drive cover 20. The segmented stator 21 only encloses the rotor over a specific segment of a circle of for example 100° or 90°. This is sufficient to drive the rotor 22 rotationally. Formed on the end face of the rotor 22 is the crank pin 9, so that the rotor 22 and the crank pin 9 together form a crank disk 7.

An example of the segmented motor will be further explained later on the basis of FIG. 4.

Variant B of FIG. 3 corresponds to variant B of FIG. 2. Accordingly, mounted as an electric motor on the inner side of the drive cover 20 is the drive motor 5, which rotationally drives a gear wheel 24 via a pinion 23 (schematically shown only as a black line). The pinion 23 and the gear wheel 24 form the gear mechanism 6. Attached to the gear wheel 24 is the crank pin 9.

Variant C of FIGS. 2 and 3 are also identical. The drive motor 5 is mounted here as an exterior electric motor. A motor shaft, not shown, of the drive motor 5 leads to a clutch bell 25, which, depending on the speed, permits or interrupts a torque flow to the pinion 23. In particular at higher motor speeds, the clutch bell 25 closes, so that the pinion 23 is rotationally driven.

In variant D, the drive motor 5 is mounted on the drive cover 20 as an exterior internal combustion engine.

In the examples shown, the complete drives, i.e. not only the drive motor 5 but also the gear mechanism 6 and possibly the clutch bell 25, are held on the drive cover 20 and are supported by it. The units shown in each case can in this way be easily pre-assembled and can be completely inserted as a whole into the crankcase 10 and attached to it.

FIG. 4 shows an example of an embodiment of the drive cover 20 for a segmented motor.

The drive cover 20 has a connection flange 26, with corresponding bores 27, in which bolts for attaching the drive cover 20 to the crankcase 10 can be inserted. In addition, the connection flange 26 may bear a seal that is not shown.

Attached on the inner side of the drive cover 20 is a bearing pin 28, on which a rotor, not shown, and possibly suitable bearing elements can be pushed. The rotor corresponds to an example of the rotor 22 shown in FIG. 3, Variant A. The bearing pin 28 may be formed in one piece with the drive cover 20. For example, the drive cover 20 may be produced together with the bearing pin 28 as a cast part. The rotor is rotatably mounted on the bearing pin 28.

Also attached on the inner side of the drive cover is a segmented stator 29, which corresponds to an example of the stator 21 shown in FIG. 3, variant A. The segmented stator 29 extends only over a certain segment of a circle, in the example shown in FIG. 4 over an angle of approx. 90°. The segmented stator 29 is bolted to the drive cover 20. At end-face ends 30 of the segmented stator 29, a cam 31 which can be pushed into a corresponding groove 32 is respectively provided on both sides. The two grooves 32 are part of the drive cover 20.

This allows the segmented stator 29 to be stably held on the drive cover 20 with interlocking engagement. The two cams 31 and the two assigned grooves 32 together respectively form a stator bracket, which supports the segmented stator 29 well in the direction of the drive torque.

The bolt pattern of the connection flange 26 predetermined by the bores 27 and their position can be identical for all variants of the drive cover 20, regardless of the drive type set up in each case. The further design of the drive cover 20 is then variable and dependent on the drive type that is to be supported by the drive cover 20.

Claims

1. A rammer kit for soil compaction rammers with different drive types, comprising: a crankcase for receiving a crank driving mechanism for converting a rotary drive motion generated by a drive into an oscillating translational motion; whereinthe crankcase has a connection opening to which a drive cover can be connected;the drive is attached to the drive cover; and whereindifferent drive covers are provided as part of the kit for drives of different drive types, while the crankcase is identical for drives of different drive types.

2. Then rammer kit according to claim 1, wherein the rammer has an upper mass and a lower mass which can be moved relative to the upper mass;the lower mass has a ramming foot with a ground contact plate for soil compaction;the crankcase is part of the upper mass; and whereinthe crank driving mechanism is designed to move the ramming foot back and forth.

3. The rammer kit according to claim 1, wherein the drive cover is completely pre-assemblable such that the drive is completely set up on the drive cover before the drive cover is placed on the crankcase.

4. The rammer kit according to claim 1, wherein the drive types are selected from the group consisting of: an internal combustion engine;an electric motor in which a drive torque of the electric motor is transmitted to the crank drive mechanism via a gear mechanism;an electric motor that is designed as a direct drive, with a rotor and a stator, wherein the rotor is formed on a motor shaft, which transmits the drive torque directly to the crank driving mechanism, without a further gear mechanism in between;an electric motor that is formed as a segmented motor, with a rotor and a stator surrounding the rotor over a segment of a circle with an angle of less than 360 degrees.

5. The rammer kit according to claim 1, wherein a connection flange is provided at a connection opening of the crankcase;each of the respective different drive covers has a connection flange adapted to be connected to the connection flange of the crankcase; and whereinthe connection flanges of the different drive covers are identical to one another.

6. The rammer kit according to claim 1, wherein the drive that is respectively assigned to each drive cover is attached directly on one side of the drive cover.

7. The rammer kit according to claim 1, wherein the crank driving mechanism has a crank pin rotationally driven by the drive.

8. The rammer kit according to claim 1, wherein the drive has an electric segmented motor; and whereinthe segmented motor has a rotor and a segmented stator which encloses the rotor not over the entire circumference but only over a segment of a circle.

9. The rammer kit according to claim 8, wherein a bearing pin is provided on an inner side of the drive cover for rotatably supporting the rotor; and whereinthe segmented stator is held on the inner side of the drive cover.

10. The rammer kit according to claim 8, wherein at least two grooved recesses are formed on the inner side of the drive cover;the segmented stator, seen in a circumferential direction thereof, has two end-face ends;a cam, which can be pushed into the respectively assigned grooved recess, is respectively formed at the two end-face ends of the segmented stator;respective pairings, each comprising a cam and a grooved recess at the two end-face ends of the segmented stator, form stator brackets which are arranged in the circumferential direction of the segmented stator.