Add-on milling unit with cross-cutting heads at an angle to each other and output gears with Belevoid toothing

Abstract

A milling unit attachment for fastening to a movable carrier arm of a carrier device permits the production of a substantially uninterrupted milling surface without requiring, for this purpose, a constant pendulum movement of the carrier arm and the milling unit attachment attached thereto.

Claims

1. Milling unit attachment comprising: a housing with a mounting bracket at the rear end of the milling unit attachment for fastening to a movable carrier arm of a carrier device, wherein the housing extends along a longitudinal axis (01); at least one motor (02); a transmission unit which is arranged in the housing, is coupled on the drive side to the at least one motor (02) and comprises a drive spur gear (04), the axis of rotation (05) of which runs perpendicular to the longitudinal axis (01) of the housing; two transverse cutter heads (06), which are rotationally driven via the transmission unit, and which are mounted on either side of the longitudinal axis (01) of the housing and carry numerous router bits (07), wherein each of the transverse cutter heads (06) has a driven pinion shaft (09), about which the transverse cutter head (06) rotates, wherein the two pinion shafts (09) of the transverse cutter heads (06) are arranged at an angle to each other and respectively form an acute angle with the longitudinal axis (01) of the housing on the side facing away from the mounting bracket; wherein an output gear wheel (10) with conical involute gears is mounted on each of the pinion shafts (09), wherein the conical involute gears of each output gear wheel (10) engage directly in an associated section of the spur gearing of the drive spur gear (04).

2. Milling unit attachment according to claim 1, wherein the drive spur gear of the transmission unit is divided into two partial drive spur gears which are parallel to each other, the common axis of rotation of which is perpendicular to the longitudinal axis (01) of the housing, and the conical involute gears of the output gear wheel (10) mounted on the pinion shafts (09) respectively engage in the spur gearing of one of the two partial drive spur gears.

3. Milling unit attachment according to claim 1, wherein each of the two output gear wheels (10) is provided with an internal gearing which is placed on external gearing of a geared connecting shaft.

4. Milling unit attachment according to claim 1, wherein, during their rotation, the router bits (07) of each transverse cutter head (06) describe a truncated conical milling lateral surface (08).

5. Milling unit attachment according to claim 4, wherein at the front end of the milling unit attachment, the two truncated conical milling lateral surfaces (08) are tangential to a common milling contact plane.

6. Milling unit attachment according to claim 1, wherein the motor (02) is a hydraulic motor mounted on a side surface of the housing.

7. Milling unit attachment according to claim 1, wherein it comprises two hydraulic motors that are mounted on opposite side surfaces of the housing.

8. Milling unit attachment according to claim 1, wherein the transmission unit comprises at least one drive pinion (03), which is directly or indirectly in driving engagement with the drive spur gear (04) via further gears.

9. Milling unit attachment according to claim 1, wherein on the side facing the front end of the milling unit attachment, an angle in the range of 150? to 170? is formed between the two pinion shafts (09) of the transverse cutter heads (06).

10. Milling unit attachment according to claim 1, wherein the distance between the milling lateral surfaces (08) described by the transverse cutter heads (06) is smaller than the width of the housing, preferably smaller than half the width of the housing of the milling unit attachment on the rear-facing side of the transverse cutter heads.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Further advantages and details of the invention will be apparent from the following description of preferred embodiments, with reference to the drawing. Wherein:

[0021] FIG. 1 shows a schematic diagram of a first embodiment of a milling unit attachment according to the invention;

[0022] FIG. 2 shows a cross-sectional drawing of a second embodiment of the milling unit attachment.

DETAILED DESCRIPTION OF THE INVENTION

[0023] FIG. 1 shows a milling unit attachment in a principle view, in which a housing and a mounting bracket, which bracket serves to attach the milling unit attachment to the support arm of an excavator or the like, are not shown for simplification. The housing, which is not shown, does however have a longitudinal extension described by a longitudinal axis 01. In this embodiment, the milling unit attachment has a high-torque motor 02, which is mounted on one side of the housing and is preferably supplied with power by the hydraulic system of the excavator. Alternatively, an electric motor can be used.

[0024] A transmission unit is arranged inside of the housing, which transmission unit is driven by the motor 02. In the embodiment shown, the transmission unit comprises a drive pinion 03, which is flanged directly onto the motor shaft. Moreover, the transmission unit comprises a drive spur gear 04 the axis of rotation 05 of which is perpendicular to the longitudinal axis 01 of the housing.

[0025] The milling unit attachment has two transverse cutter heads 06 which are driven in rotation via the transmission unit, which cutter heads are mounted on both sides of the longitudinal axis 01 of the housing and carry numerous router bits 07, wherein the router bits are shown only in the case of the transverse cutter head located on the right in the drawing. During rotation of the transverse cutter heads 06, these router bits 07 describe a truncated conical milling lateral surface 08 symbolized by dashed lines. Each transverse cutter head 06 is seated on a driven pinion shaft 09 about which the transverse cutter head rotates. The two pinion shafts 09 of the transverse cutter heads are arranged at an angle to each other. Preferably, they enclose an angle in the range from 150? to 170?. The enclosed angle is preferably selected in such a way that the truncated conical milling lateral surfaces 08 lie with their lateral line or line of contact facing the milling surface in a common plane, which plane is vertical to the longitudinal axis 01 of the housing. In other words, the pinion shafts 09 respectively enclose an acute angle with the longitudinal axis 01 of the housing at the front end, preferably at an angle of approx. 75? to 85?.

[0026] In order to set the transverse cutter heads into rotation, an output gear wheel 10 with conical involute gears is respectively mounted on each pinion shaft 09, wherein the conical involute gears of each output gear wheel 10 engage directly in an associated section of the spur gearing of the drive spur gear 04.

[0027] FIG. 2 shows a modified embodiment of the milling unit attachment in a cross-sectional view. The direct engagement of the conical involute gears of the output gear wheels 10 in the associated, lateral sections of the straight gearing of the drive gear 04 is clearly visible here. On the side opposite the circumference of the drive gear 04, the drive pinion 03 engages in the central area of the gearing. This arrangement has the advantage that there is uniform application of load and thereby uniform wear occurs over the gearing surface on the drive gear. Whereas the driving force is applied to the central area of the gearing, it is dissipated to the output gear wheels 10 at the lateral area of the gearing, which are not brushed by the drive pinion 03. The special conical involute gears nevertheless ensure that the gearing does not change in the axial direction of the drive pinion, which is to say, along the individual tooth flanks, whereby a simple and inexpensive production of the drive pinion remains possible.