Attached milling unit with cross-cutting heads arranged at angle to each other and driven gear having beveled teeth, and construction machine having such attached milling unit

Abstract

The present invention relates to an attachment milling unit, the housing of which has an attachment bracket for attachment to a movable carrier arm of a carrier device. The housing extends along a longitudinal axis (01). Furthermore, the attached milling unit comprises at least one motor (02) and a transmission unit, the axis of rotation (05) of the drive spur gear (04) of which is perpendicular to the longitudinal axis (01) of the housing. Two transverse cutting heads (06) driven in rotation by a transmission unit are attached to both sides of the longitudinal axis (01) of the housing and carry a plurality of milling and chipping knives (07). Each transverse cutting head (06) has a driven output shaft (09) about which the transverse cutting head (06) rotates, the two output shafts (09) of the transverse cutting head (06) being arranged at an angle to each other and each at an acute angle to the longitudinal axis (01) of the housing on the side facing away from the attachment bracket. The output shafts (09) are each attached with a driven gear (10) having bevel teeth, wherein each bevel tooth directly meshes with an associated spur tooth segment of the driving spur gear (04).

Description

Technical Field

[0001] The invention relates to an attachment milling unit having two crosscutting heads arranged at an angle to each other. The attachment milling unit comprises a housing, which is provided with an attachment bracket at the rear end of the attachment milling unit for attachment to a movable support arm of a carrying device (preferably an excavator or similar construction machinery). In addition, the attachment milling unit also comprises at least one motor and a transmission unit, which is arranged in the housing and coupled to the at least one motor on the drive side. Finally, two crosscutting heads driven in rotation by the transmission unit are attached to both sides of the longitudinal axis of the housing, wherein each crosscutting head carries a plurality of milling cutters and each crosscutting head has a driven output shaft, around which the crosscutting head rotates.

[0002] The application areas of such attached milling systems are, in particular, canal construction, road construction, specialized civil engineering, tunneling or hydraulic engineering. For example, the milling machine can be used both to break up sealing surfaces and to remove concrete and certain soil and rock layers. Background Art

[0003] Existing excavator-attached milling cutters are designed as cross-cutting head milling cutters equipped with carbide round-shank chisels as cutting tools. When using this type of milling cutter, the milling cutter usually needs to be shaken back and forth to break up the material between the cutting heads. The disadvantage of this type of milling cutter is that the cutting width is greater than the actual width of the milling head, which is particularly disadvantageous in channel engineering. Another disadvantage of this type of milling cutter is the load on the excavator's rotating gear, which will continue to be subjected to huge torsional and shear forces during the milling process.

[0004] Excavator-mounted milling cutters are also frequently used in the mining of soft and medium-hard rock, such as limestone or gypsum. In gypsum mining, it is particularly important to minimize the fine particles in the milled material. When using excavator-mounted milling cutters with side cutting heads, these cutting heads swing over the excavation wall and the material cut off by the front cutting head is unintentionally further crushed by the following cutting head.

[0005] Patent document DE10041275B4 discloses a milling system attached to a hydraulic carrier, which is composed of two or more attached milling cutters of the same or different structures and the same or different tool holders, each of which is driven separately and simultaneously by a hydraulic motor. The attached milling cutters can be arranged interchangeably left and right, front and back, or at angles to each other through an attached bracket, with the same or different heights. In this way, the material in front of the carrier can be removed more efficiently. However, this milling system is very complicated and is not very suitable for operations such as trenching.

[0006] Patent document US 7,096,609 B2 discloses a so-called trencher equipped with a milling chain. The trencher comprises a screw shaft attached perpendicularly to the direction of travel of the milling chain, which pushes the excavated soil away from the excavated trench. The disadvantage of this type of machine is its limited applicability. Such trenchers are not suitable for large-scale removal of material from walls. Due to their elevated design, trenchers are also subject to high mechanical stresses, which occur not only in the longitudinal direction of the rotating milling chain, but also in the direction perpendicular to the milling chain, in particular when the milling cutter encounters stones or similar obstacles.

[0007] Patent document DE102008041982A1 describes an attachment milling system for a movable support arm attached to a carrying device. The attachment milling system includes an attachment stand, and a rotating cutting head is attached to both sides of the longitudinal axis of the attachment stand. In addition, the attachment milling system also includes a spiral milling chain, whose travel direction is parallel to the longitudinal axis of the attachment stand and extends between the two cutting heads. Several milling cutters are attached to the milling chain and the cutting head, and when the cutting head rotates, these milling cutters mill out a cylindrical milling surface. The milling cutters of the milling chain form a semi-cylindrical surface at the exposed front end of the milling chain. The front end reversal line of the milling chain is basically located on a plane tangent to the milling surfaces of the two cutting heads. The contact line between the milling cutter of the cutting head and the surface to be milled is adjacent to the contact line of the milling cutter of the milling chain, and there is no obvious gap between the two. In a machine without a milling chain, the gap depends on the width of the attachment bracket. Suitably, these contact lines are also located on the same plane. This allows for an uninterrupted milling surface and may eliminate the need for an attached milling system for lateral oscillation, but the system is expensive to construct, especially since the milling chain is subject to severe wear problems.

[0008] Patent document WO2021 / 239225A1 describes a drum cutting device for a vehicle. The drum cutting device includes: a main part with a longitudinal extension; a first rotary cutting drum and a second rotary cutting drum connected to the main part and arranged on opposite sides of the main part; and a drive system for driving the first cutting drum and the second cutting drum. The first cutting drum can rotate about a first axis, and the second cutting drum can rotate about a second axis. The first axis and the second axis are perpendicular to the longitudinal extension of the main part with respect to a first plane, wherein the first axis and the second axis are at an angle to each other. Driving the two cutting drums is a transmission system with a complex design. The main part has at least one central spur gear and two laterally attached bevel gears, which interact with two other bevel gears associated with the cutting drum. In this way, two bevel gear sets (double bevel gear pairs) consisting of two bevel gears are symmetrically arranged on opposite sides of the central spur gear. Thereby, the main part consists of three gears, namely a central spur gear and two lateral bevel gears, which drive other bevel gears located on the cutting drum shaft. This configuration is very complex and requires frequent maintenance. Summary of the invention

[0009] Starting from the prior art, the object of the present invention is to provide an improved attachment milling unit for a movable support arm attached to a carrier device, which can be manufactured more simply and at a lower cost, while creating a substantially uninterrupted milling surface without requiring a continuous oscillation of the support arm and the attachment milling unit fixed thereto. In particular, the drive gear is inexpensive and durable.

[0010] Furthermore, the present invention is also directed to an improved construction machine with such an attached milling unit.

[0011] In order to achieve the above-mentioned object, the present invention proposes an attached milling unit according to claim 1 and a construction machine according to claim 11 .

[0012] In the attached milling unit according to the invention, the two output shafts of the crosscutting head are arranged at an angle to each other, and the two output shafts each make an acute angle with the longitudinal axis of the housing on the side facing away from the attachment bracket. In this way, on the side facing the front end of the attached milling unit, the angle between the two output shafts of the crosscutting head ranges from 135° to 175°, preferably from 160° to 170°. Thereby, the crosscutting heads are tilted to each other so that the milling surfaces milled by the rotating milling head are closer together on the front side of the crosscutting head than on the rear side. In particular, the spacing between the milling surfaces is smaller than the width of the housing, preferably smaller than half the width of the housing of the attached milling unit on the rear side of the crosscutting head. In a preferred case, the spacing between the milling surfaces is only a few centimeters.

[0013] Furthermore, the invention is characterized in that the transmission unit comprises a driving spur gear, the rotation axis of which is perpendicular to the longitudinal axis of the housing. Thereby, the tooth tip line of each tooth of the driving spur gear is transverse to the longitudinal axis of the housing, and thus preferably parallel to the milling contact line milled at the front end of the attached milling unit when the crosscutting head rotates. Furthermore, a driven gear with bevel teeth (also called a tapered spur gear) is attached to each of the two output shafts of the crosscutting head, wherein the bevel teeth of each driven gear directly mesh with the associated spur tooth segment of the driving spur gear.

[0014] In this way, the present invention can minimize the area that the milling head of the cross-cutting head cannot reach between these cutting heads without installing a milling chain between the cutting heads. At the same time, a transmission device equipped with a small number of gears is adopted to achieve structural stability, reduce wear and reduce maintenance requirements.

[0015] Compared with the prior art, since no double bevel gear set is used, only one spur gear with straight teeth and two gears with bevel teeth (directly driven by the straight teeth) are needed, the use of bevel teeth can significantly simplify the design, especially the structure is more compact.

[0016] Preferably, each of the two driven gears is provided with internal teeth which are inserted into the external teeth of the toothed connecting shaft. The connecting shaft connects the internal teeth of the output shaft with the internal teeth of the driven gear bearing the bevel teeth. Preferably, the output shaft is supported in an output housing with two tapered roller bearings. The right crosscutting head and the left crosscutting head are respectively mounted on the output shaft.

[0017] According to a certain improved embodiment, the transmission unit comprises two mutually parallel partial drive spur gears, and the common rotation axis of the two partial drive spur gears is perpendicular to the longitudinal axis of the housing. In this case, a driven gear with bevel teeth is also attached to the two output shafts, wherein the bevel teeth of each driven gear mesh with the spur teeth of one of the two drive spur gears.

[0018] Particularly preferably, the milling cutter of each crosscutting head mills a truncated cone-shaped milling surface during its rotation. In particular, the two truncated cone-shaped milling surfaces attached to the front end of the milling unit are tangential to a common milling contact surface, that is, the milling contact line defined by two adjacent crosscutting head segments extends in a common plane, which is preferably perpendicular to the longitudinal axis of the housing.

[0019] A certain advantageous embodiment is characterized in that the motor is a hydraulic motor, which is preferably fixed to the side of the housing and can alternatively be built into the housing. According to another improved embodiment, the attached milling unit can include two hydraulic motors, which are preferably fixed to opposite sides of the housing. The two hydraulic motors can be used together to drive the above-mentioned drive spur gear or to drive two drive gears that rotate independently of each other. In the latter case, the two crosscutting heads are driven independently of each other, thereby achieving separate speed control. For example, under certain conditions, one of the two crosscutting heads can be made to rotate more slowly than the other, or even stop rotating completely. This makes it easier to mill curved grooves, etc., and reduces the wear of the crosscutting heads.

[0020] Preferably, the transmission unit comprises at least one driving pinion which is drivingly meshed with the driving spur gear directly or indirectly through other gears. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The preferred embodiments of the present invention are explained below in conjunction with the accompanying drawings, from which more advantages and details of the present invention can be understood.

[0022] In the figure:

[0023] Figure 1 A schematic diagram showing a first embodiment of an attached milling unit according to the present invention;

[0024] Figure 2 A cross-sectional view of a second embodiment of the inventive attached milling unit is shown. DETAILED DESCRIPTION

[0025] Figure 1 A schematic diagram of an attached milling unit is shown, without, for the sake of simplicity, the housing and the attachment bracket for fixing the attached milling unit to the support arm of an excavator or similar machine. However, the housing (not shown) has a longitudinal extension depicted by a longitudinal axis 01. In this embodiment, the attached milling unit has a high torque motor 02, which is attached to one side of the housing and is preferably powered by the hydraulic system of the excavator. Alternatively, an electric motor can also be used.

[0026] Arranged inside the housing is a transmission unit driven by a motor 02. In the embodiment shown, the transmission unit comprises a drive pinion 03 directly connected to the motor shaft via a flange. In addition, the transmission unit comprises a drive spur gear 04, whose axis of rotation 05 is perpendicular to the longitudinal axis 01 of the housing.

[0027] The attached milling unit has two crosscutting heads 06, which are driven to rotate by a transmission unit, attached to both sides of the longitudinal axis 01 of the housing, and carry several milling cutters 07, of which only the milling cutters are shown on the right crosscutting head in this figure. During the rotation of the crosscutting head 06, these milling cutters 07 mill out a truncated cone-shaped milling surface 08, which is indicated by a dotted line. Each crosscutting head 06 is located on a driven output shaft 09, around which the crosscutting head rotates. The two output shafts 09 of the crosscutting head are arranged at an angle to each other. Preferably, the angle between the two output shafts 09 ranges from 150° to 170°. Preferably, the angle is selected so that the truncated cone-shaped milling surface 08 is located in a common plane with its envelope or contact line facing the milling surface, which is perpendicular to the longitudinal axis 01 of the housing. In other words, the output shafts 09 each make an acute angle with the longitudinal axis 01 of the housing at the front end, preferably about 75° to 85°.

[0028] In order to rotate the crosscutting head, a driven gear 10 with bevel teeth is attached to each output shaft 09 , wherein the bevel teeth of each driven gear 10 directly mesh with the corresponding spur tooth segment of the driving spur gear 04 .

[0029] Figure 2 A sectional view of an improved embodiment of the attached milling unit is shown. It can be clearly seen from the figure that the bevel teeth of the driven gear 10 mesh directly with the associated straight tooth side area of ​​the driving spur gear 04. The driving pinion 03 is located on the opposite side of the circumference of the driving spur gear 04 and meshes with the central tooth area. The advantage of this arrangement is that the load can be applied evenly, so that the wear on the tooth flanks of the driving gear is even. When the driving force acts on the central tooth area, it is transmitted to the lateral tooth area that is not meshing with the driving pinion 03 and is transmitted to the driven gear 10. The special bevel teeth ensure that the toothing does not change in the axial direction of the driving gear (that is, along the individual tooth flanks), so that the driving gear can be produced simply and cost-effectively.

[0030] List of Reference Numerals

[0031] 01 Shell longitudinal axis

[0032] 02Motor

[0033] 03Drive pinion

[0034] 04 Driving spur gear

[0035] 05Rotation axis of driving spur gear

[0036] 06 Horizontal cutting head

[0037] 07 Milling Chisel

[0038] 08 Milling surface

[0039] 09 Output shaft of cross cutting head

[0040] 10 driven gear

Claims

1. An attached milling unit, comprising: - a housing provided with an attachment bracket at the rear end of the attachment milling unit for attachment to a movable support arm of a carrying 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 to the at least one motor (02) on the drive side and comprises a drive spur gear (04), the rotation axis (05) of which is perpendicular to the longitudinal axis (01) of the housing; - two crosscutting heads (06), which are driven to rotate via the transmission unit, are attached to both sides of the longitudinal axis (01) of the housing, and carry a plurality of milling cutters (07), wherein each of the crosscutting heads (06) has a driven output shaft (09), about which the crosscutting head (06) rotates, wherein the two output shafts (09) of the crosscutting heads (06) are arranged at an angle to each other and each forms an acute angle with the longitudinal axis (01) of the housing on the side facing away from the attachment bracket, It is characterized in that A driven gear (10) with bevel teeth is attached to each of the output shafts (09), wherein the bevel teeth of each driven gear (10) directly mesh with the corresponding spur tooth segment of the driving spur gear (04).

2. The attached milling unit according to claim 1, characterized in that The driving spur gear of the transmission unit is divided into two mutually parallel partial driving spur gears, the common rotation axis of the two partial driving spur gears is perpendicular to the longitudinal axis (01) of the housing, and the bevel teeth of the driven gear (10) respectively attached to the output shaft (09) are meshed with the spur teeth of one of the two partial driving spur gears.

3. The attached milling unit according to claim 1 or 2, characterized in that: Each of the two driven gears (10) is provided with internal teeth which are inserted into the external teeth of the gear connection shaft.

4. The attached milling unit according to any one of claims 1 to 3, characterized in that The milling cutter (07) of each crosscutting head (06) mills out a truncated cone-shaped milling surface (08) when the milling cutter (07) rotates.

5. The attached milling unit according to claim 4, characterized in that The two truncated cone-shaped milling surfaces (08) at the front end of the attached milling unit are tangent to the common milling contact surface.

6. The attached milling unit according to any one of claims 1 to 5, characterized in that The motor (02) is a hydraulic motor fixed to the side of the housing.

7. The attached milling unit according to any one of claims 1 to 5, characterized in that The attached milling unit includes two hydraulic motors fixed to opposite sides of the housing.

8. The attached milling unit according to any one of claims 1 to 7, characterized in that The transmission unit comprises at least one driving pinion (03), which is directly or indirectly drivingly engaged with the driving spur gear (04) through other gears.

9. The attached milling unit according to any one of claims 1 to 8, characterized in that On the side facing the front end of the attached milling unit, the angle between the two output shafts (09) of the crosscutting head (06) ranges from 150° to 170°.

10. The attached milling unit according to any one of claims 1 to 9, characterized in that The spacing between the milling surfaces (08) milled by the crosscutting head (06) is smaller than the width of the housing, preferably smaller than half the width of the housing to which the milling unit is attached on the rear side of the crosscutting head.

11. An engineering machine, wherein the movable support arm comprises a fastening mechanism for an attachment unit, characterized in that: The fastening mechanism is detachably mounted with an attached milling unit according to any one of claims 1 to 10 .

12. The construction machine according to claim 11, characterized in that: The engineering machinery is designed as an excavator.

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