Unbalance Exciter for Vibratory Plates

Abstract

An unbalance exciter for a vibratory plate includes a rotatably mounted unbalance shaft, on which an unbalance mass is provided. The exciter includes an exciter housing for the unbalance shaft, at least two bearing devices for the rotatable mounting of the unbalance shaft, and two bearing seats for the bearing devices. The exciter housing has a central part and two end parts arranged at the ends of the central part. The central part has a hollow-cylindrical recess in which a bearing point is provided for each of the bearing devices. The the central part is designed to optionally accommodate an unbalance shaft for either a first drive type in which the unbalance exciter can be driven by a drive device provided outside the exciter housing, or a second drive type in which the unbalance exciter can be driven by a drive device provided inside the exciter housing.

Claims

1. An unbalance exciter for a vibratory plate for ground compaction, comprising: a rotatably mounted unbalance shaft, on which an unbalance mass is provided to generate an unbalance, an exciter housing which at least partly surrounds the unbalance shaft, and at least two bearing devices for the rotatable mounting of the unbalance shaft in the exciter housing; wherein the unbalance shaft has two bearing seats, on each of which one of two bearing devices are provided to support the unbalance shaft; wherein the exciter housing has a central part; the exciter housing has two end parts arranged at ends of the central part; the central part has a hollow-cylindrical recess, in which two bearing points are provided, one for each of the two bearing devices; the central part is designed to optionally accommodate an unbalance shaft for one of two different drive types; a first drive type is provided in which the unbalance exciter can be driven by a drive device provided outside of the exciter housing of the unbalance exciter; and wherein a second drive type is provided in which the unbalance exciter can be driven by a drive device provided inside of the exciter housing of the unbalance exciter.

2. The unbalance exciter as claimed in claim 1, wherein a central installation space is formed between the two bearing points and, therefore, between the two bearing devices, and wherein the central part is designed to accommodate optionally one of first and second different designs of an unbalance shaft, corresponding to the first and second drive types, wherein the first unbalance shaft design is one in which the unbalance mass is provided in the central installation space and in which the unbalance shaft has a shaft extension outside the central installation space, via which the unbalance shaft can be driven by a drive provided outside the exciter housing; or the second unbalance shaft design is one in which the unbalance mass is arranged outside the central installation space and in which an electric motor is provided inside the central installation space as a drive for the unbalance exciter.

3. The unbalance exciter as claimed in claim 1, wherein, in the first unbalance shaft design, the shaft extension of the unbalance shaft carries a torque transmission device to introduce a drive torque from the drive.

4. The unbalance exciter as claimed in claim 1, wherein, in the second unbalance shaft design, a respective shaft extension, on which a respective partial unbalance mass is arranged, is formed on the unbalance shaft on both end sides thereof.

5. The unbalance exciter as claimed in claim 2, wherein, in the second unbalance shaft design, the electric motor has a rotor which is arranged in a region between the two bearing seats on the unbalance shaft.

6. The unbalance exciter as claimed in claim 2, wherein, in the second unbalance shaft design, the electric motor has a stator which is inserted into the central part in a region between the two bearing points.

7. The unbalance exciter as claimed in claim 1, wherein at least one sub-region having a conical taper is provided in the region of the central part between the two bearing points.

8. The unbalance exciter as claimed in claim 1, wherein the stator can be pressed into the region of the central part between the two bearing points; and wherein a mounting stop is provided in the region of the central part between the two bearing points.

9. The unbalance exciter as claimed in claim 1, wherein, in the second drive type, a terminal device is arranged on the outer side of the central part for feeding electric lines to the stator (17) of the electric motor.

10. The unbalance exciter as claimed in claim 1, wherein identical bearing devices are provided for both of the first and second unbalance shaft designs.

11. The unbalance exciter as claimed in claim 1, further comprising at least two or more rotatably mounted unbalance shafts, on each of which an unbalance mass is provided to provide an unbalance; and wherein the unbalance shafts are mounted jointly in the exciter housing.

12. A vibratory plate for ground compaction, comprising: an unbalance exciter including: a rotatably mounted unbalance shaft, on which an unbalance mass is provided to generate an unbalance, an exciter housing which at least partly surrounds the unbalance shaft, and at least two bearing devices for the rotatable mounting of the unbalance shaft in the exciter housing; wherein the unbalance shaft has two bearing seats, on each of which one of two bearing devices are provided to support the unbalance shaft, wherein the exciter housing has a central part, the exciter housing has two end parts arranged at ends of the central part, the central part has a hollow-cylindrical recess, in which two bearing points are provided, one for each of the two bearing devices, the central part is designed to optionally accommodate an unbalance shaft for one of two different drive types, a first drive type is provided in which the unbalance exciter can be driven by a drive device provided outside of the exciter housing of the unbalance exciter, and wherein a second drive type is provided in which the unbalance exciter can be driven by a drive device provided inside of the exciter housing of the unbalance exciter; and a drive device for driving the unbalance exciter, wherein in the case of the first drive type, the drive device comprises an internal combustion engine or electric motor provided outside of the exciter housing of the unbalance exciter; and wherein in the case of the second drive type, the drive device comprises an electric motor provided inside the exciter housing of the unbalance exciter.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] These further advantages and features of the invention will be explained in more detail below with reference to examples and with the aid of the accompanying figures, in which:

[0041] FIG. 1 shows a perspective view of an unbalance exciter for a first drive type by a drive motor provided outside the unbalance exciter;

[0042] FIG. 2 shows a vertical section through the unbalance exciter from FIG. 1;

[0043] FIG. 3 shows a perspective view of an unbalance exciter according to a second drive type for a drive provided inside the unbalance exciter;

[0044] FIG. 4 shows a vertical section through the unbalance exciter from FIG. 3; and

[0045] FIG. 5 shows a perspective sectional illustration of a central part of the exciter housing of the unbalance exciter from FIGS. 1 to 4.

DETAILED DESCRIPTION

[0046] FIGS. 1 and 2 show an unbalance exciter for a first drive type in a perspective and sectional illustration.

[0047] The unbalance exciter has an exciter housing 1, in which an unbalance shaft 2 is rotatably mounted. The exciter housing 1 can be fixed to a ground contact plate, not shown, by means of screw connections 1a, in order in this way to be able to use the vibrations generated by the unbalance exciter effectively for ground compaction by the ground contact plate.

[0048] In a variant not illustrated in the figures, the exciter housing can also be made in one piece or integrally with the ground contact plate. For example, the exciter housing and the ground contact plate can be produced as a casting.

[0049] The exciter housing 1 has a central part 3 and two end parts 4 arranged at the ends of the central part 3.

[0050] In the variant that is not illustrated, in which the exciter housing is made in one piece with the ground contact plate, the central part of the exciter housing can in particular accordingly be made in one piece with the ground contact plate, for example in the form of an integral casting.

[0051] Provided on the unbalance shaft 2 is an unbalance mass 5 which in a known way, during rotation of the unbalance shaft 2 about its central axis or axis of rotation X, generates the desired circumferential unbalance force, which can be used in a vibratory plate for ground compaction.

[0052] The unbalance shaft 2 is rotatably mounted in the central part 3 of the exciter housing 1 via two bearings 6. For this purpose, the unbalance shaft 2 has two bearing seats 7. In a corresponding way, two bearing points 8, on which the outer rings of the bearings 6 rest, are provided in the central part.

[0053] The bearings 6 can be—as shown in FIG. 2—rolling contact bearings (here: grooved ball bearings), which can be designed in accordance with the strength requirement. Suitable for this purpose are, in particular, the grooved ball bearings shown in FIG. 2, but also cylindrical roller bearings, etc. Alternatively, the bearings 6 can also be formed as sliding bearings.

[0054] The unbalance shaft 2 has at one end a shaft extension 9, to the end of which a belt pulley 10 is attached.

[0055] The end parts 4 also serve as cover parts, wherein one end part 4 (the left-hand one in FIG. 2) is completely closed, while the other end part 4 (the right-hand one in FIG. 2) has a through hole, through which the shaft extension 9 of the unbalance shaft 2 is guided.

[0056] The gap between the end part 4 and the shaft extension 9 is sealed off by a seal 11.

[0057] Via the belt pulley 10 and a belt drive 30, the unbalance shaft 2 can be driven by an external drive device 31 or drive motor provided outside the unbalance exciter shown in the figures, in particular one provided outside the exciter housing 1. Instead of the belt pulley 10, another device for introducing torque into the unbalance shaft 2 can also be used.

[0058] For example, an internal combustion engine or an electric motor is suitable as a drive motor. The drive by such a drive device provided outside the exciter housing 1 of the unbalance exciter is understood as a first drive type.

[0059] FIGS. 3 and 4 show an unbalance exciter for a second drive type in a perspective and sectional illustration. The same or analogous components to those in the embodiment of FIGS. 1 and 2 are designated by the same designations.

[0060] In this embodiment, an exciter housing 1 having the central part 3 is likewise provided. The central part 3 is identical to the central part 3 of the embodiment of FIGS. 1 and 2. In addition, the two end parts 4 are used as a part of the exciter housing. While the end parts 4 of the first embodiment have a rather flat shape (FIG. 2), the end parts 4 of the second embodiment (FIG. 4) are curved to be similar to a cap, in order to enclose the unbalance shaft 2. For this purpose, it is possible for the end parts 4 to be identical in the second embodiment. In particular, no end part 4 having a through hole is needed, as is the case in the first embodiment.

[0061] Arranged in the interior of the exciter housing 1 is the unbalance shaft 2, in which shaft extensions 12 to each of which partial unbalance masses 13 are attached are present at both ends. The partial unbalance masses 13 can correspond in their overall effect to the unbalance action of the unbalance mass 5 of the first embodiment.

[0062] Also part of the unbalance shaft 2 are bearing rings 2a, on which there are the bearing seats 7 for the bearings 6. In this way, the unbalance shaft 2 is also arranged on bearing points 8 in the interior of the central part 3 of the exciter housing 1 in this embodiment. The identical bearing can thus be used in both drive types.

[0063] Between the two bearings 6 there is formed a space, which is designated as a central installation space 14, and in which an electric motor 15 is arranged. The electric motor 15 has a rotor 16 and a stator 17. The rotor 16 is fixed to the unbalance shaft 2 in a suitable way, for example by pressing on. The stator 17 is pressed into the recess in the central part 3. In this way, the electric motor 15 with the unbalance shaft 2 can be installed in a very simple way in the interior of the central part 3.

[0064] Thus, a variant in which the unbalance exciter can be driven by a drive device provided inside the exciter housing 1 is understood as a second drive type. This drive device in the present case is the electric motor 15.

[0065] In addition, a terminal box 18 is provided on the outside of the central part 3 for the connection of an electric feed line 19 for the electric motor 15 in the interior of the exciter housing 1. A hole not shown in the figures is provided in the central part 3 to introduce the electric feed line 19.

[0066] FIG. 5 shows the central part 3 in a sectional illustration.

[0067] The central part 3 has a substantially hollow-cylindrical recess. Provided at the ends are the bearing points 8, as already explained above.

[0068] At the ends, there can additionally be holes 20, to which the end parts 4 can be screwed.

[0069] A conical taper 21 with a low slope angle can be formed in the interior of the central part 3, which makes it possible to press the stator 17 (FIG. 4) axially against the conical taper and to clamp it firmly.

[0070] To define the pressing position, there is a stop 22, which a pressing tool can strike as the stator 17 is pressed in, in order that the stator 17 assumes the desired axial position in the conical taper 21.

[0071] According to the invention, the central part 3 can be used in both variants of the unbalance exciter, that is to say in the first and in the second drive type. This makes it possible to make and stock only one design of a central part 3 for the exciter housing 1 for the production of the unbalance exciter. The multiplicity of parts otherwise required because of the different drive variants can therefore be avoided.