Impact-resistant cutting arm for hard rock heading machine

Abstract

The utility model belongs to the technical field of cutting arms, and particularly relates to an impact-resistant cutting arm for a hard rock heading machine. Comprising a cantilever cylinder; the cutting main shaft is installed in the cantilever cylinder, a self-aligning roller bearing, a thrust bearing and a cylindrical roller bearing are sequentially arranged between the cutting main shaft and the cantilever cylinder from front to back, a framework oil seal II is arranged behind the cylindrical roller bearing, and a framework oil seal I is arranged in front of the self-aligning roller bearing; the front end of the cantilever cylinder is provided with a floating sealing frame sleeved on the cutting main shaft, the front end of the floating sealing frame is provided with a floating sealing seat sleeved on the cutting main shaft, the floating sealing seat is provided with a mechanical labyrinth seal, and a floating seal is arranged between the floating sealing frame and the floating sealing seat; and the cutting head is fixed at the front end of the cutting main shaft. When the cutting arm of the hard rock heading machine is used for cutting rocks of which the compressive strength is more than 70MPa, the service life of the cutting arm is prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of cutting arms, in particular to an impact-resistant cutting arm for a hard rock tunneling machine. Background Art

[0002] At present, during the operation of hard rock tunnel boring machines: the cutting arm transmits torque to the cutting head through the involute spline of the main shaft, and the cutting head and the cutting arm are fastened by bolts, or 1 to 2 bolts are fastened at the front end of the cutting head, or the rear end of the cutting head is fastened by a circle of bolts through a packing seat; the cutting arm is composed of a cutting spindle, a cantilever cylinder, a floating seal, a floating seal seat, a floating seal frame, a plate of spherical roller bearings or a group of tapered roller bearings, a group of full roller bearings, an oil seal, a bushing, a spacer, etc., which belongs to the traditional cutting arm and cutting head structure, suitable for full rock and semi-coal rock conditions with rock compressive strength below 70MPa, but the cutting arm is extremely uneconomical for full rock conditions with rock compressive strength between 70MPa and 100MPa.

[0003] The existing problems are as follows: When the tunnel boring machine is cutting hard rock, the impact load and vibration of the rock wall on the cutting head cause the front end fastening bolts of the cutting head to loosen and fall off, and the rear end fastening bolts of the cutting head to wear and cannot be disassembled; dust enters around the floating seal, destroying the sealing performance of the floating seal, and then the floating seal leaks oil, or the work inside the bearing cavity causes the cavity temperature to rise, and the existence of air pressure breaks through the front and rear seals to exhaust and cause front and rear seals to leak oil; under the action of the impact load, the internal bearing clearance of the cutting arm increases, and then the bearing is damaged. This greatly reduces the service life of the cutting arm under this working condition. Therefore, it is particularly important to design an impact-resistant cutting arm for hard rock tunnel boring machines. Summary of the invention

[0004] In order to solve the problem of service life of a cutting arm, the utility model provides an impact-resistant cutting arm for a hard rock tunneling machine.

[0005] The utility model adopts the following technical scheme: an impact-resistant cutting arm for a hard rock tunnel boring machine, comprising:

[0006] cantilever cylinder;

[0007] A cutting spindle, wherein the cutting spindle is installed in the cantilever tube, and a spherical roller bearing, a thrust bearing and a cylindrical roller bearing are sequentially arranged between the cutting spindle and the cantilever tube from front to back, wherein a skeleton oil seal II is arranged behind the cylindrical roller bearing, and a skeleton oil seal I is arranged in front of the spherical roller bearing; a floating seal frame sleeved on the cutting spindle is installed at the front end of the cantilever tube, a floating seal seat sleeved on the cutting spindle is installed at the front end of the floating seal frame, a mechanical labyrinth seal is arranged on the floating seal seat, and a floating seal is arranged between the floating seal frame and the floating seal seat;

[0008] A cutting head is fixed at the front end of the cutting spindle.

[0009] In some embodiments, 5-8 oil holes are provided on the floating seal frame.

[0010] In some embodiments, a vent plug is provided on the cantilever tube so that the heat after work done inside the cavity can be discharged to the outside in time.

[0011] In some embodiments, the front end of the cutting head is fastened to the axial end surface of the cutting spindle by a cutting head fastening bolt.

[0012] In some embodiments, the rear end of the cutting head is axially fixed on the floating seal seat by 2-4 positioning pins.

[0013] Compared with the prior art, the utility model has the following beneficial effects:

[0014] 1. When the hard rock tunnel boring machine is cutting rock with a compressive strength of less than 100MPa in full rock working conditions, the cutting head will not fall off due to the breakage or loosening of the fastening bolts;

[0015] 2. When the hard rock tunnel boring machine is cutting rock with a compressive strength of less than 100MPa in full rock working conditions, the cutting head of the rear end fastening structure is severely worn at the rear end, causing the bolt head and the packing seat to grind together, making it impossible to unscrew the bolts and disassemble the cutting head;

[0016] 3. The floating seal of the cutting arm will not wear and leak oil due to inadequate dust protection;

[0017] 4. When the hard rock tunnel boring machine is cutting rock with a compressive strength below 100 MPa in full rock working conditions, the cutting arm can fully resist the cluster loads from the axial and radial directions, and the cutting arm will not end its service due to premature bearing failure;

[0018] 5. When the cutting arm is performing cutting operations, the rotating parts such as bearings and grease rotate and do work, causing the inside of the bearing cavity to heat up. The severe temperature can reach 70°C, and a certain air pressure is formed inside. Exhaust holes are designed at the corresponding positions on the cantilever tube to extend the service life of the seal. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the connection between the cantilever cylinder and the cutting spindle of the utility model;

[0020] Figure 2 It is a schematic diagram of the floating seal frame structure;

[0021] Figure 3 It is a schematic diagram of the connection between the cutting spindle and the cutting head;

[0022] Figure 4 It is a schematic diagram of the floating seal seat structure;

[0023] In the figure, a-cutting spindle, b-cantilever cylinder, c-cutting head, 1-floating seal seat, 2-floating seal frame 3-floating seal, 4-skeleton oil seal, 5-spherical roller bearing, 6-thrust bearing, 7-breathing plug, 8-cylindrical roller bearing, 9-skeleton oil seal, 10-fastening bolt, 11-double-stacked self-locking washer, 12-elastic retaining ring for hole, 13-pull screw, 14-locating pin, 15-oil hole. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the utility model clearer, the technical solutions in the embodiments of the utility model will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all of the embodiments; based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0025] like Figure 1 , 3 As shown, an impact-resistant cutting arm for a hard rock tunnel boring machine comprises a cantilever tube b, a cutting spindle a and a cutting head c, wherein the cutting head c is fixed at the front end of the cutting spindle a. The cutting spindle a is installed in the cantilever tube b, and a spherical roller bearing 5, a thrust bearing 6 and a cylindrical roller bearing 8 are arranged in sequence from front to back between the cutting spindle a and the cantilever tube b, wherein a skeleton oil seal II9 is ​​arranged behind the cylindrical roller bearing 8, and a skeleton oil seal I4 is arranged in front of the spherical roller bearing 5; a floating seal frame 2 sleeved on the cutting spindle a is installed at the front end of the cantilever tube b, a floating seal seat 1 sleeved on the cutting spindle a is installed at the front end of the floating seal frame 2, a mechanical labyrinth seal is arranged on the floating seal seat 1, and a floating seal 3 is arranged between the floating seal frame 2 and the floating seal seat 1.

[0026] The floating seal frame 2 is provided with 5 to 8 oil holes 15 .

[0027] The cutting arm solves the problem of seal oil leakage. The floating seal 3 is a key dynamic sealing element. The mechanical labyrinth seal of the floating seal seat 1 prevents external dust from invading the floating seal, providing a clean environment for the floating seal 3. The sealing principle of the floating seal 3 is to form an oil film between the two sealing rings, which is an oil film seal. However, if the floating seal is directly connected to the bearing cavity, a large amount of gear oil will surge at the front end of the cutting arm, that is, the floating seal. Since the cutting arm cuts hard rock, impact and vibration coexist, the dynamic and static rings of the floating seal 3 will squeeze the internal gear oil out of the floating seal, resulting in oil leakage. Therefore, a skeleton oil seal I4 is installed on the inner side of the floating seal 3, and 5-8 φ6 oil holes are made above the floating seal frame 2, so that the gear oil in the bearing cavity is transported to the specific position of the cutting arm. The appropriate amount of lubricating oil required for the floating oil seal is used to form an oil film, creating a good working environment for the floating seal 3.

[0028] In addition, the cutting arm operates in an all-rock condition with a compressive strength of less than 100 MPa. The reaction force from the rock wall causes the cutting arm to frequently receive axial and radial impact loads. Through the reasonable coordination of bearings and axial dimensions, from left to right, the first group of bearings are designed as spherical roller bearings 5 ​​or tapered roller bearings and the third group of cylindrical roller bearings 8, which bear the radial load from the rock wall. The second group of bearings are designed as thrust bearings 6. Special dimension chain control allows the axial load from the rock wall to act completely on the thrust bearing 6, giving full play to the load-bearing capacity advantages of different types of bearings and extending the service life of the bearings.

[0029] A vent plug 7 is provided on the cantilever tube b so that the heat after work inside the cavity can be discharged to the outside in time, avoiding the formation of air pressure inside the bearing cavity and causing damage to the bearing and the seal.

[0030] The front end of the cutting head c is fastened to the axial end face of the cutting spindle a by the cutting head fastening bolts 10. The rear end of the cutting head c is axially fixed to the floating seal seat 1 by 2-4 positioning pins 14. The front end of the cutting head is fastened to the axial end face of the cutting spindle by the cutting head fastening bolts, and the rear end is assisted in axial limitation by 2-4 positioning pins and their accessories. The 2-4 positioning pins 14 are directly inserted from the cutting head into the outer waist groove of the floating seal seat. When the cutting head cuts hard rock, it is frequently impacted and vibrated, and the cutting head fastening bolts M36 are easy to loosen and back out. At this time, the rear end 2-4 positioning pins and their accessories limit the cutting head axially to prevent the cutting head from falling off.

[0031] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the utility model, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effect and purpose that can be achieved by the utility model, should still fall within the scope of the technical content disclosed by the utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the utility model. The change or adjustment of the relative relationship, without substantial change of the technical content, should also be regarded as the scope of the implementation of the utility model.

Claims

1. An impact-resistant cutting arm for a hard rock tunnel boring machine, characterized in that: include: Cantilever tube (b); A cutting spindle (a), wherein the cutting spindle (a) is installed in a cantilever tube (b), and a spherical roller bearing (5), a thrust bearing (6) and a cylindrical roller bearing (8) are arranged in sequence from front to back between the cutting spindle (a) and the cantilever tube (b), wherein a skeleton oil seal II (9) is arranged behind the cylindrical roller bearing (8), and a skeleton oil seal I (4) is arranged in front of the spherical roller bearing (5); a floating seal frame (2) sleeved on the cutting spindle (a) is installed at the front end of the cantilever tube (b), a floating seal seat (1) sleeved on the cutting spindle (a) is installed at the front end of the floating seal frame (2), a mechanical labyrinth seal is arranged on the floating seal seat (1), and a floating seal (3) is arranged between the floating seal frame (2) and the floating seal seat (1); The floating seal frame (2) is provided with 5 to 8 oil holes (15); A vent plug (7) is provided on the cantilever tube (b) so that the heat generated after work is done inside the cavity can be discharged to the outside in a timely manner; A cutting head (c), wherein the cutting head (c) is fixed at the front end of the cutting spindle (a).

2. The impact-resistant cutting arm for a hard rock tunnel boring machine according to claim 1, characterized in that: The front end of the cutting head (c) is fastened to the axial end surface of the cutting main shaft (a) by means of a cutting head fastening bolt (10).

3. The impact-resistant cutting arm for a hard rock tunnel boring machine according to claim 2, characterized in that: The rear end of the cutting head (c) is axially fixed on the floating sealing seat (1) via 2 to 4 positioning pins (14).

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