Shaft cutter with unbalanced roller cutter

Abstract

The utility model relates to the technical field of cutter, disclose the partial load hob for vertical shaft cutter head, including the cutter shaft and first cutter ring, the circumferential outside of first cutter ring is fixedly installed with second cutter ring through the snap spring, the both ends of first cutter ring all are set up and communicate with each other the step hole, and the both ends step hole installs bearing, end face seal and end cover from inside to outside in proper order, bearing, end face seal and end cover all cover the cutter shaft, and the cutter shaft still covers and is used for abutting the interval ring of bearing, the circumferential side left end of cutter shaft is provided with the shoulder, and right end sets up the external thread, and the left end end cover sets up the shoulder groove for clamping shoulder, and the right end end cover sets up the internal thread for screwing the external thread. The utility model realizes the accurate matching of axial, radial carrying capacity through the bearing selection difference configuration, effectively solves the problem of traditional symmetrical bearing group partial load failure, prolongs the service life of bearing.

Description

Technical Field

[0001] This utility model relates to the field of hobbing technology, specifically to an off-center hobbing cutter for a vertical shaft cutterhead. Background Technology

[0002] In vertical shaft excavation operations, the tunneling machine drives the roller cutters on the cutter box to break rocks by rotating a conical cutterhead.

[0003] Traditional hobs use a symmetrically distributed double tapered roller bearing structure of the same model. The inclined arrangement of the tapered cutter head causes the hob to bear a compound off-center load, of which the axial component accounts for a significant proportion upward. Under long-term off-center load conditions, stress concentration, abnormal changes in bearing clearance, and shortening of the overall service life of the hob will occur.

[0004] When symmetrical bearing assemblies experience unilateral overload failure, using small contact angle bearings for all bearings will result in insufficient radial load capacity, while using large contact angle bearings for all bearings will result in redundant axial load capacity, thus leading to design waste.

[0005] Therefore, in order to solve the above problems, an off-center loading hob for vertical shaft cutterheads is proposed. Utility Model Content

[0006] The purpose of this invention is to provide an off-center load hob for a vertical shaft cutterhead, which rationally allocates bearing types, thereby solving the problems mentioned in the background art.

[0007] To achieve the above objectives, this utility model provides the following technical solution: Technical Solution 1: A hob for a vertical shaft cutterhead is provided, comprising a cutter shaft and a first cutter ring. A second cutter ring is fixedly mounted on the outer circumference of the first cutter ring by a retaining spring. Both ends of the first cutter ring have interconnected stepped holes. A bearing, an end face seal, and an end cap are sequentially installed in the stepped holes from the inside to the outside. The bearing, end face seal, and end cap are all sleeved on the cutter shaft. The cutter shaft is also sleeved with a spacer ring for abutting the bearing. The left end of the circumference of the cutter shaft is provided with a shoulder, and the right end is provided with an external thread. The left end cap has a shoulder groove for engaging the shoulder, and the right end cap has an internal thread for threading the external thread. The bearing in the stepped hole at the left end is a large contact angle tapered roller bearing, and the bearing in the stepped hole at the right end is a small contact angle tapered roller bearing.

[0008] Specifically, the spacer ring includes a first cylindrical ring, and there is one of each of the large contact angle tapered roller bearing and the small contact angle tapered roller bearing. The cutter shaft is fitted with the first cylindrical ring, and the first cylindrical ring abuts between the large contact angle tapered roller bearing and the small contact angle tapered roller bearing.

[0009] Technical Solution Two: Another type of off-center hob for vertical shaft cutterheads is provided, which differs from technical solution one in the distribution of the large contact angle tapered roller bearings and the form of the spacer rings.

[0010] The spacer ring includes a housing and a second housing. There are two large contact angle tapered roller bearings and one small contact angle tapered roller bearing. The small contact angle tapered roller bearing and the large contact angle tapered roller bearing on the right side are abutted by the second housing. The cutter shaft is fitted with a housing. The large contact angle tapered roller bearing on the left side is fitted on the housing. The right end of the housing is provided with a flange, which abuts between the two large contact angle tapered roller bearings.

[0011] Furthermore, a gap is left between the cylinder seat and the end cap on the left end.

[0012] Specifically, a placement groove is provided at the center of the end of the cutter shaft, and a strain gauge force sensor is fixedly installed in the placement groove.

[0013] Compared with the prior art, the beneficial effects of this utility model are: The left end uses a tapered roller bearing with a large contact angle to enhance axial load, while the right end uses a tapered roller bearing with a small contact angle to improve radial load. This avoids design redundancy or insufficient radial force. Through this differentiated configuration of bearing selection, the axial and radial load capacities are precisely matched, effectively solving the problem of eccentric load failure in traditional symmetrical bearing sets.

[0014] It reduces stress concentration and abnormal changes in bearing clearance, extends bearing service life, lowers the overall cost of shaft construction, improves tunneling efficiency and equipment reliability, and better meets the actual needs of shaft cutterhead under off-center loading conditions. Attached Figure Description

[0015] Figure 1 This is a schematic cross-sectional view of the structure of Embodiment 1 of this utility model; Figure 2 This is a schematic cross-sectional view of the structure of Embodiment 2 of this utility model.

[0016] In the figure: 1. Cutter shaft, 2. End cover, 3. First cutter ring, 4. Large contact angle tapered roller bearing, 5. First cylindrical ring, 6. Small contact angle tapered roller bearing, 7. End face seal, 8. Second cutter ring, 9. Strain gauge force sensor, 10. Cylindrical base, 11. Second cylindrical ring. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Example 1: Please see Figure 1 A hob for a vertical shaft cutterhead is provided, including a cutter shaft 1 and a first cutter ring 3. A second cutter ring 8 is fixedly installed on the outer circumference of the first cutter ring 3 by a retaining spring. An annular groove for placing the second cutter ring 8 is opened on the outer circumference of the first cutter ring 3. The second cutter ring 8 is fixed on the annular groove by interference fit and is axially limited by the retaining spring.

[0019] Both ends of the first cutter ring 3 are provided with interconnected stepped holes. The diameter of the stepped holes increases from the inside to the outside. Bearings, end face seals 7 and end caps 2 are installed in the stepped holes from the inside to the outside. The bearings, end face seals 7 and end caps 2 are all sleeved on the cutter shaft 1. The cutter shaft 1 is also sleeved with a spacer ring for abutting the bearings.

[0020] When in use, the cutter shaft 1 is mounted on the cutter holder. The first cutter ring 3 can rotate on the cutter shaft 1 through the bearing. The end caps 2 at both ends are used to press the internal end face seal 7 and the bearing, thereby adjusting the sealing strength of the end face seal 7 and the preload of the bearing.

[0021] Each end face seal 7 consists of two rotating sealing rings that are set in opposite directions to ensure sealing performance and prevent dust, water and other foreign objects from entering the bearing through the gap at the edge of the end cover 2, thereby contaminating the lubricating oil or damaging the bearing.

[0022] In addition, a screw hole is provided on the end cover 2, and a plug is screwed into the screw hole, which makes it convenient to open the plug during inspection and maintenance and fill the internal cavity of the hob with lubricating oil.

[0023] The cutter shaft 1 has a shoulder on the left side of its circumference and an external thread on the right side. The left end cover 2 has a shoulder groove for engaging the shoulder, and the right end cover 2 has an internal thread for engaging the external thread. The left end cover 2 is limited by the shoulder, while the right end cover 2 adjusts the pressure by screwing the thread.

[0024] The right end cap 2 also has a groove on its right end face. There are four grooves arranged in a circle to facilitate the insertion of a torque wrench into the groove, thereby applying torque and facilitating the screwing of the right end cap 2.

[0025] To accommodate the installation and distribution of conical cutterheads: The bearing in the stepped hole at the left end is a tapered roller bearing with a large contact angle 4, such as the bearing with model number H924033-010, with a contact angle α=0.67 and stronger axial load capacity; the bearing in the stepped hole at the right end is a tapered roller bearing with a small contact angle 6, such as HH224335-310, with a contact angle α=0.33 and stronger radial load capacity.

[0026] Different models of bearings are selected at the left and right ends to better adapt to the stress conditions of the roller cutter during the tunneling process of the conical cutterhead, reduce bearing wear, and ensure the overall service life of the roller cutter.

[0027] The spacer ring includes a first cylindrical ring 5, and there is one large contact angle tapered roller bearing 4 and one small contact angle tapered roller bearing 6. The cutter shaft 1 is fitted with the first cylindrical ring 5, and the first cylindrical ring 5 abuts between the large contact angle tapered roller bearing 4 and the small contact angle tapered roller bearing 6.

[0028] The first cylindrical ring 5 is used to support the inner rings of the large contact angle tapered roller bearing 4 and the small contact angle tapered roller bearing 6, and to transmit the abutment force on the right end cover 2, thereby changing the preload of the large contact angle tapered roller bearing 4 and the small contact angle tapered roller bearing 6, and thus changing the torque on the first cutter ring 3 and the second cutter ring 8.

[0029] Job Description: When installing the cutter head, install the cutter head on the cutter box of the conical cutter head of the tunneling machine, and fix the cutter shaft 1 with bolts. At this time, the axis of the cutter shaft 1 is parallel to the conical surface of the conical cutter head, and the small contact angle tapered roller bearing 6 is below the large contact angle tapered roller bearing 4.

[0030] During tunneling operations, the cutterhead rotates with the cutterhead and tunnels downwards. The cutterhead experiences a greater upward eccentric load. The small contact angle tapered roller bearing 6 is mainly used to provide radial load, while the large contact angle tapered roller bearing 4 is mainly used to provide axial load. By coordinating the load-bearing capacities of different bearings, the cutterhead is better suited for eccentric load operations, ensuring its service life.

[0031] Example 2: Please see Figure 2 Another type of off-center hob for vertical shaft cutterheads is provided, which differs from the first embodiment in the distribution of the large contact angle tapered roller bearing 4 and the form of the spacer ring, as detailed below.

[0032] For the same overall volume of hob, compared with the large contact angle tapered roller bearing 4 and the small contact angle tapered roller bearing 6 in Embodiment 1, the large contact angle tapered roller bearing 4 and the small contact angle tapered roller bearing 6 are selected with smaller volume. However, there are two large contact angle tapered roller bearings 4, which are more suitable for hob operation with off-center loading.

[0033] That is, the spacer ring includes a housing 10 and a second housing 11. There are two large contact angle tapered roller bearings 4 and one small contact angle tapered roller bearing 6. The small contact angle tapered roller bearing 6 and the large contact angle tapered roller bearing 4 on the right side are abutted by the second housing 11. The cutter shaft 1 is fitted with the housing 10. The large contact angle tapered roller bearing 4 on the left side is fitted on the housing 10. The right end of the housing 10 is provided with a flange, which abuts between the two large contact angle tapered roller bearings 4.

[0034] The cylinder seat 10 and the flange are integrally formed. The cylinder seat 10 is used to support the large contact angle tapered roller bearing 4 on the left side, so that the large contact angle tapered roller bearing 4 on the left side can be installed in the left end stepped hole in the correct position. The diameter of the large contact angle tapered roller bearing 4 on the left side is larger than the diameter of the large contact angle tapered roller bearing 4 on the right side. The two large contact angle tapered roller bearings 4 work together to better axially support the first cutter ring 3.

[0035] In addition, the second cylindrical ring 11 and the cylindrical seat 10 are used to transmit the abutment force on the right end cap 2, thereby adjusting the preload force on the two large contact angle tapered roller bearings 4 and the small contact angle tapered roller bearing 6.

[0036] To prevent the housing 10 from affecting the preload adjustment of the left-side large contact angle tapered roller bearing 4, a gap is left between the housing 10 and the left end cover 2, providing conditions for the outer ring of the left-side large contact angle tapered roller bearing 4 to abut against the left end cover 2.

[0037] To further understand the stress conditions of the hob: A placement groove is provided at the center of the end of the cutter shaft 1. A strain gauge force sensor 9 is fixedly installed in the placement groove by means of screwing and high-strength adhesive. When in use, the strain gauge force sensor 9 is electrically connected to the controller in the tunneling machine and detects the load by measuring the small deformation of the cutter shaft 1 when it is subjected to force.

[0038] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0039] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A shaft cutter head with eccentric loading hob, comprising a cutter shaft (1) and a first cutter ring (3), wherein a second cutter ring (8) is fixedly mounted on the outer circumference of the first cutter ring (3) by a retaining spring, characterized in that: The first cutter ring (3) has interconnected stepped holes at both ends. The stepped holes at both ends are installed with bearings, end face seals (7) and end caps (2) from the inside to the outside. The bearings, end face seals (7) and end caps (2) are all sleeved on the cutter shaft (1). The cutter shaft (1) is also sleeved with a spacer ring for abutting the bearing. The cutter shaft (1) has a shoulder on the left side of its circumference and an external thread on the right side. The end cap (2) on the left side has a shoulder groove for engaging the shoulder, and the end cap (2) on the right side has an internal thread for engaging the external thread. The bearing in the stepped hole at the left end is a tapered roller bearing with a large contact angle (4), and the bearing in the stepped hole at the right end is a tapered roller bearing with a small contact angle (6).

2. The off-center loading hob for a vertical shaft cutterhead according to claim 1, characterized in that: The spacer ring includes a first cylindrical ring (5), and there is one of each of the large contact angle tapered roller bearing (4) and the small contact angle tapered roller bearing (6). The cutter shaft (1) is fitted with the first cylindrical ring (5), and the first cylindrical ring (5) abuts between the large contact angle tapered roller bearing (4) and the small contact angle tapered roller bearing (6).

3. The off-center loading hob for a vertical shaft cutterhead according to claim 1, characterized in that: The spacer ring includes a housing (10) and a second housing (11). There are two large contact angle tapered roller bearings (4) and one small contact angle tapered roller bearing (6). The small contact angle tapered roller bearing (6) and the large contact angle tapered roller bearing (4) on the right side are connected by the second housing (11). The cutter shaft (1) is fitted with a housing (10). The large contact angle tapered roller bearing (4) on the left side is fitted on the housing (10). The right end of the housing (10) is provided with a flange. The flange abuts between the two large contact angle tapered roller bearings (4).

4. The off-center loading hob for a vertical shaft cutterhead according to claim 3, characterized in that: There is a gap between the cylinder seat (10) and the end cap (2) on the left.

5. The off-center loading hob for a vertical shaft cutterhead according to claim 1, characterized in that: A placement groove is provided at the center of the end of the cutter shaft (1), and a strain gauge force sensor (9) is fixedly installed in the placement groove.

Images