Attachment milling unit with transversely cut heads arranged at an angle to each other and driven gear with bevel teeth and engineering machine with such attachment milling unit

Abstract

This invention relates to an attached milling unit, the housing of which has an attachment bracket for attachment to a movable support arm of a carrier. The housing extends along a longitudinal axis (01). Furthermore, the attached milling unit includes at least one motor (02) and a transmission unit, the axis of rotation (05) of which is perpendicular to the longitudinal axis (01) of the housing. Two cross-cutting heads (06) driven to rotate by the transmission unit are attached to both sides of the longitudinal axis (01) of the housing and carry several milling cutters (07). Each cross-cutting head (06) has a driven output shaft (09) about which it rotates, wherein the two output shafts (09) of the cross-cutting head (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 opposite to the attachment bracket. Each output shaft (09) is attached with a driven gear (10) having helical teeth, wherein each helical tooth directly meshes with the corresponding spur tooth segment of the drive spur gear (04).

Description

Technical Field

[0001] This invention relates to an attached milling unit having two cross-cutting heads arranged at an angle to each other. The attached milling unit includes a housing with an attachment bracket at its rear end for attachment to a movable boom of a load-bearing device (preferably an excavator or similar construction machinery). Furthermore, the attached milling unit includes at least one motor and a transmission unit, the transmission unit being arranged within the housing and coupled to the at least one motor on the drive side. Finally, two cross-cutting heads, driven to rotate by the transmission unit, are attached to both sides of the longitudinal axis of the housing, each cross-cutting head carrying several milling cutters, and each cross-cutting head having a driven output shaft about which it rotates.

[0002] The application areas for this type of milling system are particularly canal construction, road construction, specialized civil engineering, tunnel or water conservancy projects. For example, milling machines can be used to break sealed surfaces, as well as to remove concrete and clear certain soil and rock layers. Background Technology

[0003] Existing excavator-mounted milling cutters are designed as cross-head milling cutters, equipped with carbide round shank chisels as cutting tools. When using this type of milling cutter, the cutter typically requires back-and-forth oscillation to break the material between the cutting heads. A 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 slewing gear; during milling, the slewing gear is constantly subjected to enormous torsional and shearing forces.

[0004] Excavator-mounted milling cutters are also frequently used for mining soft and medium-hard rocks, 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 lateral cutting heads, these heads oscillate across the excavation face, and the material cut by the preceding cutting head can be unintentionally further pulverized by subsequent cutting heads.

[0005] Patent document DE10041275B4 discloses a milling system attached to a hydraulic support device. This system consists of two or more attached milling cutters with identical or different structures and identical or different tool holders, each tool holder being driven simultaneously and individually by a hydraulic motor. The attached milling cutters can be arranged interchangeably left-right, front-back, or at angles to each other via attached supports, with the heights being the same or different. This allows for more efficient removal of material in front of the support device. However, this milling system is very complex and not well-suited for tasks such as trenching.

[0006] Patent document US7,096,609B2 discloses a so-called trenching machine equipped with a milling chain. The trenching machine includes a helical shaft attached perpendicular to the direction of travel of the milling chain, which pushes the excavated soil away from the dug trench. A disadvantage of such machinery is its limited applicability. This trenching machine is not suitable for large-scale removal of material from wall surfaces. Due to its elevated design, the trenching machine is also subjected to high mechanical stresses, occurring not only longitudinally along the rotating milling chain but also perpendicularly, particularly when the milling cutter encounters rocks or similar obstacles.

[0007] Patent document DE102008041982A1 describes an attachment milling system for a movable support arm attached to a load-bearing device. This attachment milling system includes an attachment frame with rotating cutting heads attached to both sides of its longitudinal axis. Furthermore, the system includes a rotating milling chain whose travel direction is parallel to the longitudinal axis of the attachment frame and extends between the two cutting heads. Several milling cutters are attached to the milling chain and the cutting heads, which mill cylindrical milling surfaces as the cutting heads rotate. The milling cutters of the milling chain form a semi-cylindrical surface at the exposed front end of the chain. The leading edge reversal line of the milling chain lies substantially on a plane tangent to the milling surfaces of the two cutting heads. The contact line between the milling cutters of the cutting heads and the surface to be milled is adjacent to the contact line of the milling cutters of the milling chain, with no significant gap between them, whereas in machinery without a milling chain, this gap depends on the width of the attachment support. Suitably, these contact lines also lie on the same plane. While this method can produce uninterrupted milled surfaces and may eliminate the need for a milling system with lateral oscillation, the construction cost of such a system is high, and the milling chain is particularly susceptible to severe wear.

[0008] Patent document WO2021 / 239225A1 describes a roller cutting device for a transport vehicle. This roller cutting device includes: a main component with a longitudinal extension; a first and a second rotary cutting roller connected to the main component and arranged on opposite sides of the main component; and a drive system for driving the first and second cutting rollers. The first cutting roller is rotatable about a first axis, and the second cutting roller is rotatable about a second axis. The first and second axes are perpendicular to the longitudinal extension of the main component about a first plane, wherein the first and second axes form an angle with each other. Driving these two cutting rollers is a complex transmission system design. The main component has at least one central spur gear and two laterally attached bevel gears that interact with two other bevel gears associated with the cutting rollers. Thus, two bevel gear sets (double bevel gear pairs) consisting of two bevel gears are symmetrically arranged on opposite sides of the central spur gear. Therefore, the main component consists of three gears: one central spur gear and two lateral bevel gears, the latter driving the other bevel gears located on the cutting roller shaft. This configuration is very complex and requires frequent maintenance. Summary of the Invention

[0009] Based on existing technology, the object of this invention is to provide an improved attached milling unit for a movable support arm attached to a load-bearing device, which simplifies the manufacturing process and reduces costs, while creating a substantially uninterrupted milling surface without requiring continuous oscillation of the support arm and the attached milling unit fixed thereon. In particular, the drive gear is inexpensive and robust.

[0010] Furthermore, the present invention also aims to provide an improved engineering machine with such an attached milling unit.

[0011] In the attached milling unit according to the invention, the two output shafts of the cross-cutting head are arranged at an angle to each other, each of the two output shafts forming an acute angle with the longitudinal axis of the housing on the side opposite to the attachment bracket. Thus, on the side facing the front end of the attached milling unit, the included angle between the two output shafts of the cross-cutting head ranges from 135° to 175°, preferably from 160° to 170°. This causes the cross-cutting heads to be tilted relative to each other, resulting in a smaller spacing between the milled surfaces cleaved by the rotating milling head on the forward side of the cross-cutting head than on the rear side. In particular, the spacing between the milled surfaces is less than the width of the housing, preferably less than half the width of the housing of the attached milling unit on the rear side of the cross-cutting head. In a preferred case, the spacing between the milled surfaces is only a few centimeters.

[0012] Furthermore, the invention is characterized in that the transmission unit includes a drive spur gear, the axis of rotation of which is perpendicular to the longitudinal axis of the housing. Thereby, the tooth tips of each tooth of the drive spur gear are transverse to the longitudinal axis of the housing, and preferably parallel to the milling contact line milled at the front end of the attached milling unit when the cross-cutting head rotates. In addition, each of the two output shafts of the cross-cutting head is attached with a driven gear (also called a bevel spur gear) having helical teeth, wherein the helical teeth of each driven gear directly mesh with the corresponding spur tooth segment of the drive spur gear.

[0013] In this way, the present invention can minimize the area that the milling head of the cross-cutting head cannot reach between these milling heads, without the need to install milling chains between the milling heads, while using a transmission device equipped with a small number of gears to achieve structural stability, reduce wear, and reduce maintenance needs.

[0014] Compared with existing technologies, since no double bevel gear set is used, only one spur gear with straight teeth and two gears with helical teeth (directly driven by the spur gear) are needed. Therefore, the use of helical teeth can significantly simplify the design, especially making the structure more compact.

[0015] Preferably, each of the two driven gears has internal teeth that are fitted onto the external teeth of the gear-type connecting shaft. The connecting shaft connects the internal teeth of the output shaft with the internal teeth of the driven gear carrying the helical teeth. Preferably, the output shaft is supported within an output housing with two tapered roller bearings. The right and left cross-cutting heads are respectively mounted on the output shaft.

[0016] According to one improved embodiment, the transmission unit includes two parallel partial drive spur gears, the common axis of rotation of which is perpendicular to the longitudinal axis of the housing. In this case, driven gears with helical teeth are also attached to the two output shafts, wherein the helical teeth of each driven gear mesh with the spur teeth of one of the two drive spur gears.

[0017] Particularly preferably, the milling cutter of each cross-cutting head mills a frustoconical milling surface as it rotates. In particular, the two frustoconical milling surfaces at the front end of the attached milling unit are tangent to a common milling contact surface, that is, the milling contact line segmented by the two adjacent cross-cutting heads extends in a common plane, which is preferably perpendicular to the longitudinal axis of the housing.

[0018] One advantageous embodiment features a hydraulic motor, which is preferably fixed to the side of the housing, or alternatively, built into the housing. According to another improved embodiment, the attached milling unit may include two hydraulic motors, preferably fixed to opposite sides of the housing. The two hydraulic motors can be used together to drive the aforementioned drive spur gear or to drive two independently rotating drive gears. In the latter case, the two cross-cutting heads are driven independently, thereby achieving individual speed control; for example, under certain conditions, one of the cross-cutting heads can rotate at a slower speed than the other, or even stop rotating completely. This makes it easier to mill curved grooves, etc., and reduces wear on the cross-cutting heads.

[0019] Preferably, the transmission unit includes at least one drive pinion, which engages directly or indirectly with the drive spur gear through other gears. Attached Figure Description

[0020] The preferred embodiments of the present invention are illustrated below with reference to the accompanying drawings, thereby revealing more advantages and details of the present invention.

[0021] In the picture:

[0022] Figure 1 A schematic diagram of a first embodiment of the present invention with a milling unit attached is shown;

[0023] Figure 2 A cross-sectional view of a second embodiment of the present invention with a milling unit attached is shown. Detailed Implementation

[0024] Figure 1A schematic diagram of the attached milling unit is shown. For simplicity, the housing and the mounting bracket for securing the attached milling unit to the boom of an excavator or similar machinery are not shown. However, the housing (not shown) has a longitudinal extension depicted by the longitudinal axis 01. In this embodiment, the attached milling unit has a high-torque motor 02 attached to one side of the housing, preferably powered by the hydraulic system of the excavator. Alternatively, an electric motor may also be used.

[0025] The housing houses a transmission unit driven by a motor 02. In the illustrated embodiment, the transmission unit includes a drive pinion 03 directly connected to the motor shaft via a flange. Furthermore, the transmission unit also includes a drive spur gear 04, whose rotation axis 05 is perpendicular to the longitudinal axis 01 of the housing.

[0026] The attached milling unit has two cross-cutting heads 06, which are driven to rotate by a transmission unit. These heads are attached to both sides of the longitudinal axis 01 of the housing and carry several milling cutters 07; only the cutters on the right cross-cutting head are shown in this figure. During the rotation of the cross-cutting heads 06, these milling cutters 07 mill out a frustoconical milling surface 08, indicated by dashed lines. Each cross-cutting head 06 is located on a driven output shaft 09 about which it rotates. The two output shafts 09 of the cross-cutting heads are arranged at an angle to each other. Preferably, the included angle between the two output shafts 09 ranges from 150° to 170°. Preferably, this included angle is chosen such that the envelope or contact line of the frustoconical milling surface 08 facing the milling surface lies in a common plane perpendicular to the longitudinal axis 01 of the housing. In other words, each output shaft 09 forms an acute angle with the longitudinal axis 01 of the housing at its front end, preferably approximately 75° to 85°.

[0027] In order to make the cutting head rotate, each of the output shafts 09 is attached with a driven gear 10 with helical teeth, wherein the helical teeth of each driven gear 10 directly mesh with the corresponding spur tooth segment of the drive spur gear 04.

[0028] Figure 2 A cross-sectional view of the improved embodiment with the attached milling unit is shown. It is clearly visible that the helical teeth of the driven gear 10 directly mesh with the corresponding spur tooth side area of ​​the drive spur gear 04. The drive pinion 03 is located on the opposite side of the circumference of the drive spur gear 04 and meshes with the central tooth area. The advantage of this arrangement is that it allows for uniform load application, resulting in uniform wear on the tooth surfaces of the drive gears. When the driving force acts on the central tooth area, it is transmitted to the lateral tooth areas not meshing with the drive pinion 03, and thus to the driven gear 10. The special helical teeth ensure that the meshing does not change axially along the drive gear (i.e., along each tooth surface), thus enabling simple and low-cost production of the drive gear.

[0029] List of reference numerals

[0030] 01 Longitudinal axis of the shell

[0031] 02 Motor

[0032] 03 Drive pinion

[0033] 04 Drive spur gear

[0034] 05 The axis of rotation of the drive spur gear

[0035] 06 Cross-cutting head

[0036] 07 Milling Cutter

[0037] 08 Milling surface

[0038] 09 Output shaft of the cross-cutting head

[0039] 10 driven gears

Claims

1. A milling unit, comprising: - A housing, wherein the housing is provided with an attachment bracket at the rear end of the attached milling unit for attachment to a movable support arm of a bearing device, wherein the housing extends along the longitudinal axis (01); - At least one motor (02); - A transmission unit, which is disposed within the housing and coupled to the at least one motor (02) on the drive side, and includes a drive spur gear (04) whose rotation axis (05) is perpendicular to the longitudinal axis (01) of the housing. - Two cross-cutting 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 several milling cutters (07), wherein each cross-cutting head (06) has a driven output shaft (09) about which it rotates, wherein the two output shafts (09) of the cross-cutting head (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 opposite to the attachment bracket. Its features are, Each of the output shafts (09) is attached with a driven gear (10) having helical teeth, wherein the helical teeth of each driven gear (10) directly mesh with the relevant spur teeth of the drive spur gear (04); each of the two driven gears (10) has internal teeth, which are inserted into the external teeth of the gear connecting shaft; the drive spur gear of the transmission unit is divided into two parallel partial drive spur gears, the common axis of rotation of the two partial drive spur gears is perpendicular to the longitudinal axis (01) of the housing, and the helical teeth of the driven gears (10) attached to the output shaft (09) mesh with the spur teeth of one of the two partial drive spur gears.

2. The attached milling unit according to claim 1, characterized in that, The milling cutter (07) of each cross-cutting head (06) mills a truncated cone milling surface (08) as it rotates.

3. The attached milling unit according to claim 2, characterized in that, The two truncated conical milling surfaces (08) at the front end of the attached milling unit are tangent to the common milling contact surface.

4. The attached milling unit according to claim 1, characterized in that, The motor (02) is a hydraulic motor fixed to the side of the housing.

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

6. The attached milling unit according to claim 1, characterized in that, The transmission unit includes at least one drive pinion (03), which directly or indirectly engages with the drive spur gear (04) via other gears.

7. The attached milling unit according to claim 1, characterized in that, On the side facing the front end of the attached milling unit, the included angle between the two output shafts (09) of the cross-cutting head (06) ranges from 150° to 170°.

8. The attached milling unit according to claim 1, characterized in that, The spacing between the milled surfaces (08) milled by the cross-cutting head (06) is less than the width of the housing.

9. The attached milling unit according to claim 1, characterized in that, The spacing between the milled surfaces (08) milled by the cross-cutting head (06) is less than half the width of the housing of the attached milling unit on the rearward side of the cross-cutting head.

10. An engineering machine, wherein the movable boom includes a fastening mechanism for attaching a unit, characterized in that, The fastening mechanism is detachably mounted with an attached milling unit according to any one of claims 1 to 9.

11. The engineering machinery according to claim 10, characterized in that, The engineering machinery is designed as an excavator.

Images