CN116443128A

CN116443128A - Thrust wheel, side cover, wheel body, sealing, fine adjusting and oiling device thereof, and mounting and dismounting tool and method

Info

Publication number: CN116443128A
Application number: CN202211625922.2A
Authority: CN
Inventors: 黄联生
Original assignee: Fujian Quanzhou Chengfa Electrical Machinery Technology Co ltd
Current assignee: Fujian Quanzhou Chengfa Electrical Machinery Technology Co ltd
Priority date: 2022-12-16
Filing date: 2022-12-16
Publication date: 2023-07-18
Also published as: WO2024124962A1

Abstract

A thrust wheel, wheel body (1) includes: the guide rails (120) and the wheel shafts (111), the guide rails (120) around the two sides of the wheel body and the wheel shafts (111) in the centers of the two sides of the wheel body are integrally formed with the wheel body; and a supporting seat (112) formed by a concave cavity formed by integral molding is arranged between the guide rail (120) and the wheel axle (111). The side cover (2) includes: the bearing seat (262) and the fixing seat (242) are integrally formed, and the connecting part (252) is used for connecting the bearing seat and the fixing seat; the fixed seat is provided with at least one fixed screw hole (24) for screw fastening, and the two side covers are respectively arranged in the supporting seat (112); the bearing (3) is supported between the outer peripheral surface of the wheel shaft and the inner wall of the bearing seat, and the chain moves in the guide rail to drive the wheel body and the wheel shaft to synchronously rotate on the inner ring (302) of the bearing, so that the function of rotating the inner ring of the bearing and preventing the outer ring (301) from rotating is realized.

Description

Thrust wheel, side cover, wheel body, sealing, fine adjusting and oiling device thereof, and mounting and dismounting tool and method

Technical Field

The invention relates to the technical field of engineering machinery, in particular to a thrust wheel, a side cover, a wheel body, a sealing, fine adjustment and oiling device, an installation tool and a disassembly tool and a method thereof.

Background

The thrust wheel is used as a core part of the excavator and the tank chassis, and the product performance of the thrust wheel directly influences the reliability and the working efficiency of the whole machine.

Currently, in the related art, a thrust wheel includes a wheel body, a wheel shaft, a bearing, an end cover, a floating oil seal, a rubber ring and a pin, wherein the bearing is pressed into the wheel body, the wheel shaft penetrates into the bearing, the floating oil seal and the rubber ring are respectively installed into the wheel body, and the two end covers are respectively fixed with the wheel shaft through the pin. The structure has complex assembly process and higher cost, and is suitable for heavy-load medium-large-tonnage excavators. Technical document CN115214813a discloses a thrust wheel comprising a wheel body, a wheel shaft and two box-type sealing members, the thrust wheel comprising two bearings and two check rings, the two bearings being respectively arranged on both sides of the first shoulder, the two check rings being respectively arranged on one side of the corresponding bearing far away from the first shoulder, the structure also being a combination of the wheel body and the wheel shaft, the axial length of the wheel shaft being greater than that of the wheel body in [0053], so as to facilitate connection of the wheel shaft with a frame or other parts, the wheel body of the structure being rotated under the drive of a chain, but the shaft being used for supporting rotation of the wheel body, the structure being incapable of realizing heavy load operation.

It should be noted that the information disclosed in the background section of the present invention is only for increasing the understanding of the general background of the present invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

The embodiment of the invention provides a thrust wheel, a side cover, a wheel body, a sealing, fine-tuning and oiling device thereof, an installation and disassembly tool and a method, which can effectively simplify the structure of the thrust wheel, reduce the cost of the thrust wheel and are suitable for heavy-load large-tonnage excavators and tanks.

According to a first aspect of the present invention,

provided is a wheel body, the wheel body includes: the guide rails and the wheel shafts are arranged on the periphery of two sides of the wheel body, and the wheel shafts in the centers of two sides of the wheel body are integrally formed with the wheel body; and a supporting seat formed by the concave cavity formed by the integral molding is arranged between the guide rail and the wheel shaft.

According to a second aspect of the present invention,

provided is a side cover including: the bearing seat, the fixing seat and the connecting part for connecting the bearing seat and the fixing seat are integrally formed, and the fixing seat is at least provided with a fixing screw hole for fastening a screw.

According to a third aspect of the present invention,

the bearing comprises a first aspect and a second aspect, wherein the bearing is supported between the outer peripheral surface of the wheel shaft and the inner wall of the bearing seat, and the chain moves in the guide rail to drive the wheel body and the wheel shaft to synchronously rotate on the inner ring of the bearing, so that the function of rotating the inner ring of the bearing and preventing the outer ring from rotating is realized.

Further, the inside of the supporting seat is a first limiting device.

Further, the bearing seat extends inwards to form a second limiting device.

Further, the inner limit of the bearing is positioned between the first limiting device and the second limiting device.

Further, the limiting device extends from the inner ring to the outer ring of the bearing, and does not touch the outer ring at maximum.

Further, the second limiting device extends from the outer ring to the inner ring of the bearing, and does not touch the inner ring at the longest.

Further, the first limiting device and the second limiting device are designed to be rough surfaces or grain surfaces.

Further, side cover installation positioning screw holes are formed in the centers of the side surfaces of the two ends of the wheel shaft, and the screw holes are of internal thread structures.

Further, the axial length of the wheel axle is less than or equal to the axial length of the wheel body.

Further, the wheel body and the wheel shaft are integrally formed.

Further, the wheel body and the side cover are preferably forged, followed by a casting process and finally by founding or turning.

According to a fourth aspect of the invention, the device further comprises a fine adjustment device for adjusting the axial displacement of the wheel axle, the fine adjustment device is screwed into the fine adjustment screw hole, and the fine adjustment device is abutted against the wheel axle.

According to a fifth aspect of the present invention, the side cover further includes a fine adjustment screw hole for adjusting axial displacement of the axle, a fine adjustment device screwed into the fine adjustment screw hole, and a sliding device disposed between the supporting axle and the fine adjustment device.

Further, the device also comprises a sliding device, wherein the sliding device is arranged between the propping wheel shaft and the fine adjustment device.

Further, the center points of the fine adjustment device, the fine adjustment screw hole and the wheel shaft are at the same level.

Further, the thread of the fine adjustment device and the thread of the fine adjustment screw hole are matched in a combined way.

Further, the sliding device is: ball bearings, balls, needle bearings, pressure ball bearings, limiting blocks and the like.

Further, the wheel axle is provided with a valve seat extending outwards, and the sliding device is sleeved on the outer diameter of the valve seat; alternatively, the axle has an inward valve seat and the sliding means is sleeved in the inner diameter of the valve seat.

Further, the side cover is provided with a fine adjustment screw hole, the fine adjustment device is screwed into the fine adjustment screw hole, and the fine adjustment device is propped against the elastic device.

Further, the device also comprises a pressure disc, wherein the pressure disc is arranged between the sliding device and the fine adjustment device; or, the pressure disc is arranged between the sliding device and the elastic device.

Further, the device also comprises an elastic device, wherein the elastic device is arranged between the sliding device and the fine adjustment device.

According to a sixth aspect of the invention, the wheel body is provided with a seat for mounting the sealing element at the joint of the side cover and the wheel body, and the seat is a groove for mounting the sealing element.

According to a seventh aspect of the present invention, the side cover is provided with a seat for mounting the sealing member at a junction of the side cover and the wheel body, and the seat is a groove for mounting the sealing member.

Further, the outer ring of the sealing element is in interference fit with the groove.

According to an eighth aspect of the present invention, the side cover is further provided with an oil adding passage.

According to a ninth aspect of the present invention, the dust cap further includes an oil adding passage.

According to a tenth aspect of the present invention, the fine adjustment device further includes an oil adding passage.

Further, one end of the oiling channel is communicated with a cavity between the side cover and the wheel body.

Further, a one-way valve is arranged at the other end of the oiling channel.

Further, the oiling channel of the fine adjustment device is communicated with the oiling channel of the dust cap.

Further, the device also comprises a dustproof cap, wherein the dustproof cap is fastened outside the fine adjustment device and is attached to the fine adjustment device.

According to an eleventh aspect of the present invention, there is provided an excavator comprising the above-described thrust wheel.

According to a twelfth aspect of the present invention, there is provided a tank including the above-described thrust wheel.

According to a thirteenth aspect of the invention, the method comprises the steps of installing a pull rod and a bearing pull nut, wherein the pull rod and the bearing pull nut are of a combined thread matching structure, and the diameter of the pull rod is smaller than the inner diameter of a fine adjustment screw hole.

According to a fourteenth aspect of the invention, the device comprises a mounting push rod, wherein the threads of the mounting push rod and the threads of the fine adjustment screw hole are of a combined matched structure.

Further, the installation pull rod or the installation push rod and the pressure sheet are of an integrated structure.

Further, the diameter of the beginning end of the side cover retreating push rod is smaller than the inner diameter of the side cover installing and positioning screw hole.

According to a fifteenth aspect of the present invention, the side cover mounting screw and the side cover pressure nut are combined and matched.

According to a sixteenth aspect of the present invention, the screw comprises a side cover mounting screw, and the screw thread of the side cover mounting screw and the screw thread of the side cover mounting positioning screw are combined matching structures.

According to a seventeenth aspect of the invention, the side cover withdrawing push rod comprises a side cover withdrawing push rod, and the threads of the side cover withdrawing push rod and the threads of the fine adjustment screw hole are of a combined matching structure.

Further, the side cover withdrawing push rod is a fine adjustment device.

Based on the technical scheme, the embodiment of the thrust wheel has the following beneficial effects:

1. the wheel body and the wheel shaft are integrally formed to realize synchronous rotation of the wheel shaft and the wheel body, so that the bearing load of the thrust wheel is effectively increased, and the installation procedure of the wheel shaft and the wheel body is reduced. The bearing replaces the tile cover, the bearing of the supporting wheel is borne by the bearing, the bearing can select the bearing corresponding to the bearing force according to the matching body, so that the bearing force of the bearing wheel is at least 5 times higher than that of the tile cover, the defects that the gap of the original tile cover is large, the load exceeds the locking of the rear tile cover are overcome, the chain passes through the wheel body, the wheel body cannot rotate due to the locking of the tile cover, the chain rubs the wheel body like a file, and the supporting wheel is scrapped are also overcome; regarding the reduction of the installation of the wheel shaft and the wheel body, the wheel body and the wheel shaft in the prior art are separated, the wheel shaft is screwed into the whole wheel body and then inserted into the side cover, and the side cover is fixed on the side cover by a bolt or a fixing screw of the side cover, and the tile covers on two sides are also required to be assembled between the wheel body and the wheel shaft, so the step of inserting the wheel shaft into the wheel body and the step of fixing the wheel shaft on the bolt of the side cover are reduced at least in the technology.

2. The fixing seat is provided with fixed screw on the side cover, and fixed screw is used for the side cover to be fixed in on the carrier, and after two side covers were fixed in the carrier (test frame, excavator, tank), can realize the spacing of bearing, and the chain drives wheel body and shaft and rotates on the bearing in step.

3. The cooperation of shaft and micromatic setting realizes preventing the axial displacement of shaft self clearance. The application of the fine adjustment structure in the invention not only realizes the purpose of preventing the displacement of the wheel axle and prolonging the service life of the bearing and the sealing element, but also realizes the disassembly function of the side cover by means of the fine adjustment device and the fine adjustment screw hole, and the function of easily installing the bearing, thereby reducing the damage to the bearing and the damage to the bearing seat ring caused by knocking in the bearing installation process.

4. The wheel axle is designed with a side cover mounting positioning screw hole, so that the side cover is conveniently mounted, and the wheel axle is positioned; the cost is saved, the efficiency is improved, and the service life of the bearing is prolonged.

5. The axial length of the wheel axle is smaller than or equal to that of the wheel body, so that the axle end bears a large load, the deformation of the wheel axle is reduced, and the service life of the sealing element is prolonged.

6. The dustproof cap realizes the dustproof effect on the oiling one-way valve and the positioning effect on the fine adjustment device.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of a wheel according to the present invention;

FIG. 2 is a schematic side cover of the present invention;

FIG. 3 is a diagram showing a wheel and side cover assembly according to the present invention;

FIG. 4 is a schematic view of a fine straightening top type of the present invention;

FIG. 5 is a schematic view of a fine ball sliding device according to the present invention;

FIG. 6 is a schematic view of a fine-tuned plain bearing slide according to the present invention;

FIG. 7 is a schematic view of a stopper sliding device according to the present invention;

FIG. 8 is a schematic view of a pressure slide apparatus according to the present invention;

FIG. 9 is a schematic view of a self-aligning ball slide of the spring assembly of the present invention;

FIG. 10 is a schematic view of a self-aligning plain bearing slide of the resilient means of the present invention;

FIG. 11 is a schematic view of a self-adjusting ball slide of the cushion gum of the present invention;

FIG. 12 is a schematic view of a self-adjusting plain bearing slide assembly of the present invention with a cushion gum;

FIG. 13 is a schematic view of an elastic slider according to the present invention;

FIG. 14 is a schematic view of a laterally disposed seal of the present invention;

FIG. 15 is a schematic view of a vertically disposed single seal of the present invention;

FIG. 16 is a schematic view of a vertically disposed dual seal of the present invention;

FIG. 17 is a schematic view of a transverse and vertical combined arrangement seal of the present invention;

FIG. 18 is a drawing of a bearing assembly of the present invention;

FIG. 19 is a press-in bearing assembly view of the present invention;

FIG. 20 is a schematic view of a direct push side cover installation of the present invention;

FIG. 21 is a schematic view of a nut pressure side cover installation of the present invention;

FIG. 22 is a schematic view showing the removal of the side cover of the trimming screw according to the present invention;

FIG. 23 is a schematic view showing the removal of a push rod side cover of the present invention;

FIGS. 24-28 are CAD line cross-sectional views of the present invention.

In the figure:

1. a wheel body; 11. the side cover is provided with a positioning screw hole; 12. a seal; 111. a wheel axle; 112. a support base; 113. a first limiting device; 120. a guide rail; 2. a side cover; 21. a fine tuning device; 211. an elastic device; 22. a dust cap; 23. fine tuning the screw hole; 24. fixing the screw holes; 242. a fixing seat; 252. a connection part; 262. a bearing seat; 263. a second limiting device; 3. a bearing; 301. an outer ring; 302. an inner ring; 31. a sliding device; 311. a pressure plate; 312. a valve seat; 32. a pull rod; 33. a push rod; 321. a pressure plate; 322. a bearing tension nut; 41. a side cover mounting screw; 411. a side cover mounting nut; 412. the side cover withdraws from the push rod; side cover pressure nut 413.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The invention provides a thrust wheel, a side cover, a wheel body, a sealing, fine-tuning and oiling device thereof, an installation and disassembly tool and a method, which can effectively simplify the structure of the thrust wheel, reduce the cost of the thrust wheel and are suitable for heavy-load large-tonnage excavators and tanks.

As shown in figures 1, 2 and 3 of the drawings,

wheel body 1, wheel body 1 includes: the guide rail 120 and the wheel axle 111, the guide rail 120 around the two sides of the wheel body 1 and the wheel axle 111 in the center of the two sides of the wheel body 1 are integrally formed with the wheel body 1; the guide rail 120 and the axle 111 are integrally formed into a concave cavity to form a supporting seat 112, and the interior of the supporting seat 112 is a first limiting device 113. The first limiting device 113 extends from the inner ring 302 of the bearing 3 to the outer ring 301, and does not touch the outer ring 301 at the longest, so that the limiting mode of the traditional bearing is changed, the limiting of the inner ring of the bearing is supported to the greatest extent under the condition that the outer ring is not touched, and noise generated by rotation of the bearing is effectively reduced. The other part of the first limiting device 113 exceeding the inner ring 302 or the first limiting device adopts a rough surface or grain surface design, which is more beneficial to eliminating the noise of the bearing 3.

A side cover 2, the side cover 2 comprising: the bearing seat 262, the fixing seat 242 and the connecting part 252 for connecting the bearing seat 262 and the fixing seat 242 are integrally formed, and the bearing seat 262 extends inwards to form a second limiting device 263. The invention benefits from the fact that the outer diameter of the connecting part 252 is smaller than that of the bearing seat 262 and the fixing seat 242, the density of the connecting part 252 after the integral molding is higher, the service life of the connecting part 252 is prolonged, and meanwhile, the inner diameter of the connecting part 252 is smaller than that of the bearing seat 262, so that the bearing 3 can play a limiting role and a role of increasing the connecting force. The second limiting device 263 extends from the outer ring 301 of the bearing 3 to the inner ring 302, and does not touch the inner ring 302 at the longest, so that the limiting mode of the traditional bearing is changed, the stress of the outer ring of the bearing is protected to the greatest extent under the condition that the inner ring is not touched, and the noise generated by rotation of the bearing is effectively reduced. The other part of the second limiting device 263 which exceeds the outer ring 301 or the second limiting device adopts a rough surface or grain surface design, which is more beneficial to eliminating the noise of the bearing 3.

The thrust wheel comprises a wheel body 1 and a side cover 2, wherein the two side covers 2 are respectively arranged in a supporting seat 112; the bearing 3 is supported between the outer peripheral surface of the wheel axle 111 and the inner wall of the bearing seat 262 and is limited in the first limiting device 113 and the second limiting device 263; the fixing seat 242 is provided with a fixing screw hole 24, the fixing screw hole 24 is used for fixing the side covers 2 on the carrier, after the two side covers 2 are fixed on the carrier, the inner ring 302 of the bearing 3 is limited between the first limiting device 113 and the second limiting device 263, the chain moves in the guide rail 120 to drive the wheel body 1 and the wheel shaft 111 to synchronously rotate on the inner ring 302 of the bearing 3, and the functions of rotating the inner ring 302 and preventing the outer ring 301 from rotating are realized. In the invention, the conventional limiting structure of the bearing is omitted, for example, the limiting is realized by combining an inner spring or an outer spring with a clamping groove, or the limiting is realized by fastening a limiting piece on the outer surface of the bearing by a screw.

Forging or casting and turning processes can be adopted in the process. Forging is carried out by heating solid materials, forging and integrally forming on a forging machine, and finishing rough surface parts by machining to obtain the wheel body 1 and the side cover 2. The wheel body 1 and the side cover 2 adopt a forging process to improve durability, the wheel body 1 and the wheel shaft 111 are integrally formed to realize synchronous rotation of the wheel shaft 1 and the wheel body 111, and the load is effectively increased to reduce defective products caused by the installation procedure and welding of the wheel shaft 111 and the wheel body 1. The invention is preferably a multi-directional hammering forging machine. The casting process and the turning process are known processes and are not stated here. In order to save the cost, the wheel body can be welded into a whole by adopting a bilateral symmetry structure, and the material and forging process cost can be reduced by adopting the mode.

In further embodiments, the bearing 3 may be: deep groove ball bearings, cylindrical roller bearings, self-aligning ball bearings, needle bearings, angular contact bearings, self-aligning roller bearings or tapered roller bearings, and the like.

The fine tuning structure, as shown in figures 4-10,

in some embodiments, as shown in fig. 4, the side cover 2 further includes a fine adjustment screw hole 23 for adjusting the axial displacement of the axle 111, a fine adjustment device 21 is screwed into the fine adjustment screw hole 23, the fine adjustment device 21 abuts against the axle 111, and the fine adjustment device 21, the fine adjustment screw hole 23, and the center point of the axle 111 are at the same level. The surface of the fine adjustment device 21, which is in contact with the axle 111, may be a plane or an arc surface, if the surface is an arc surface, the arc surface may be inserted into the center point of the axle 111 to apply force to the periphery of the center of the axle 111, and this structure can prevent the wheel axle from jumping to damage the wheel body 1 and the side cover 2 under the condition of damage of the bearing. Fixing the assembled thrust wheel to the carrier by means of the fixing screw holes 24; after the fine adjustment device 21 rotates against the wheel axle 111, the fine adjustment device 21 moves back a certain distance in the opposite direction; the two sides synchronously operate above, so that the bearing 3 does not have any play gap, but flexibly rotates to be standard.

As shown in fig. 5, 6, 7 and 8, in some embodiments, the side cover 2 further includes a fine adjustment screw hole 23 for adjusting the axial displacement of the axle 111, a fine adjustment device 21 screwed into the fine adjustment screw hole 23, and a sliding device 31 disposed between the supporting axle 111 and the fine adjustment device 21, wherein the fine adjustment device 21, the fine adjustment screw hole 23 and the center point of the axle 111 are at the same level. When the sliding device 31 adopts balls, the axle 111 is provided with an inward concave arc valve seat, and the fine adjustment device 21 is also provided with an inward concave arc valve seat, and the valve seat is used for supporting the positioning of the balls; when the sliding device 31 adopts a needle bearing, the wheel axle 111 is provided with an inward concave valve seat, the valve seat is an inward step, the inner diameter of the sliding seat is slightly larger than the outer diameter of the needle bearing, and the needle bearing is embedded in the valve seat; when the sliding device 31 adopts a limiting block, one surface of the limiting block is provided with a concave hole, the concave hole is used for supporting the insertion of the fine adjustment timing screw 21, a gap is reserved between the concave hole and the fine adjustment device 21, the other surface of the limiting block is propped against the wheel shaft 111, and the other end of the limiting block is propped against the fine adjustment device 21; when the sliding device 31 adopts a pressure ball bearing, the axle 111 has an outwardly protruding valve seat 312, the pressure ball bearing is sleeved on the outer diameter of the valve seat, one end of a pressure disc 311 is propped against the sliding device 31, the other end is propped against the fine adjustment device 21, and the pressure disc 311 is U-shaped. Fixing the assembled thrust wheel to the carrier by means of the fixing screw holes 24; after the fine adjustment device 21 rotates to push the sliding device 31 against the wheel axle 111, the fine adjustment device 21 moves back a certain distance in the opposite direction; the two sides synchronously operate above, so that the bearing 3 does not have any play gap, but flexibly rotates to be standard.

The threads of the fine adjustment device 21 and the threads of the fine adjustment screw hole 23 are of a combined structure, the fine adjustment device 21 can achieve the function of inwards extending or outwards withdrawing by means of force rotation in the fine adjustment screw hole, and the limit of the wheel axle 111 is achieved by extending or withdrawing of the fine adjustment screw 21. The design can effectively reduce the side impact of displacement play on the bearing 3, so that the service life of the bearing 3 is prolonged, meanwhile, the chain is ensured to be on the same working surface, the swinging of the chain is reduced, and the service life of the chain is prolonged.

As shown in fig. 9 to 13, in some embodiments, the self-adaptive device further includes an elastic device 211 for adjusting the axial displacement of the axle 111, a sliding device 31 disposed between the supporting axle 111 and the elastic device 211, and the other end of the elastic device 211 is supported inside the side cover 2. In another embodiment, a sliding device 31 is a pressure ball bearing, the axle 111 has a valve seat 312 extending outwards, the pressure ball bearing is sleeved on the outer diameter of the valve seat, and an elastic device 211 has one end abutting against the sliding device 31 and the other end abutting against the inside of the side cover 2. The other end of the elastic device 211 in the adaptive case can also be sleeved into the fine tuning screw hole 23 and then abutted against the dust cap 22. After the side cover is installed, the wheel axle 111 is centered based on the thrust of the elastic device 211, the design is suitable for medium and light load, when the chain or the guide rail 120 is worn, when a certain part of the chain is abnormal, the wheel axle 111 is displaced leftwards or rightwards, under the action of the elastic device 211, the wheel axle is automatically reset and centered, the re-abrasion of the abnormal abrasion position is reduced, and the service life of the wheel body 1 is prolonged. The dust cap 22 and the fine tuning screw hole 23 contained in the drawing can be removed in production, and can also be reserved, so that the functions of bearing installation and side cover disassembly can be realized. The elastic means 211 may be a spring, as in fig. 9, 10, 13, or a rubber, as in fig. 11, 12, a hydraulic damping device or other resettable means.

In some embodiments, a fine adjustment device 21 is added in the case of the self-adaptive type, the side cover 2 further includes a fine adjustment screw hole 23 for adjusting the axial displacement of the axle 111, an elastic device 211 is sleeved in the fine adjustment screw hole 23, a sliding device 31 is disposed between the supporting axle 111 and the elastic device 211, the other end of the elastic device 211 supports against the fine adjustment device 21, and the fine adjustment device 21, the fine adjustment screw hole 23 and the center point of the axle 111 are at the same level. Fixing the assembled thrust wheel to the carrier by means of the fixing screw holes 24; the fine adjustment device 21 rotates to push the elastic device 211 to the sliding device 31 to abut against the wheel axle 111; the two sides synchronously operate above, so that the bearing 3 does not have any play gap, but flexibly rotates to be standard. In this embodiment, the elastic device 211 may also be disposed in the side cover 2, as shown in fig. 13, instead of being sleeved in the fine tuning screw hole 23, and the fine tuning device 21 extends out of the fine tuning screw hole 23 and abuts against the elastic device 211. The design is suitable for medium and high load, the fine adjustment device 21 can strengthen the reset force of the elastic device 211 to adapt to different wear degrees of the chain or the guide rail 120, when a certain link of the chain is abnormal to cause the left or right displacement of the wheel shaft 111, after the abnormal link passes through the wheel body 1, the wheel shaft is automatically reset and centered under the action of the elastic device 211, the re-abrasion of the abnormal abrasion position is reduced, and the service life of the wheel body 1 is prolonged.

The application of the fine adjustment structure in the invention not only realizes the prevention of the displacement of the wheel axle 111, the reduction of the side friction force of the bearing 3 and the lip abrasion of the sealing element 12, the prolongation of the service life of the bearing 3 and the sealing element 12 by more than two times, but also realizes the function of simply and conveniently assembling and disassembling the side cover 2, and realizes the easy installation of the bearing 3 and the reduction of the damage to the bearing 3 and the damage to the seat ring of the bearing seat 262 caused by knocking in the installation process of the bearing 3, especially for the market after maintenance, the on-site maintenance does not need to use a hydraulic device or other professional tools to ensure the assembly quality.

The sealing structure, as shown in figures 14-17,

the wheel body 1 or the side cover 2 is provided with a seat for installing the sealing element 12 at the joint of the side cover 2 and the wheel body 1, the seat is a groove for installing the sealing element 12, and the outer ring of the sealing element 12 is in interference fit with the groove. The sealing element 12 is arranged between the side cover 2 and the wheel body 1, the sealing element 12 comprises an inner ring and an outer ring, the inner ring and the outer ring can rotate relatively under the sealing condition, the wheel shaft 111 rotates easily under the support of the bearing 3 when the chain drives the wheel body 1 to rotate, at the moment, the bearing 3 is arranged in the side cover 2 and positioned in the sealing element 12, and the influence of muddy water on the service life of the bearing can be effectively avoided. The wheel body 1 is provided with a seat for installing the sealing element 12, and the sealing element 12 and the wheel body 1 are transversely arranged relative to the structure shown in fig. 14, in the other way, the side cover 2 is provided with a seat for installing the sealing element 12, and the sealing element 12 and the wheel body 1 are transversely arranged, so that the installation of the side cover is not influenced by the lip of the sealing element during the installation of the structure; in order to meet the requirements of more sealing modes and convenient operation in the processing process, as shown in fig. 15, the wheel body 1 is provided with seats for installing the sealing element 12, the sealing element 12 and the wheel body 1 are vertically arranged, and special environments and severe areas such as a puddle and marshland are vertically arranged, the sealing element 12 and the wheel body 1 are vertically arranged, and the wheel body 1 is provided with double seats for installing the sealing element 12, as shown in fig. 16, so as to meet the requirements of the special environments; in another way, the side cover 2 is vertically provided with a seal 12 mounting seat, which is a further way of achieving a simple mounting of the seal. Of course, the seal 12 and thrust wheel may also be of a design as described above in combination with a transverse arrangement and a vertical arrangement, as shown in fig. 17.

The oil filling structure comprises a main body and a main body,

as an application of the bearing support structure in the present invention, in order to facilitate the post-maintenance of the bearing 3 or the sliding device 31, scheme one: a fueling channel is arranged on the dust cap 22 or the side cover 2, one end of the fueling channel is communicated with a cavity between the side cover 2 and the wheel body 1, and the other end of the fueling channel is connected with a fueling check valve. Scheme II: the fine adjustment device 21 is provided with a refueling passage, one end of the refueling passage leads to a cavity between the side cover 2 and the wheel body 1, the other end of the refueling passage is connected with a refueling one-way valve, and the dustproof cap 22 achieves the dustproof effect on the refueling one-way valve and the positioning effect on the fine adjustment device 21. Scheme III: the fine adjustment device 21 and the dust cap 22 are provided with oiling channels, one end of each oiling channel of the fine adjustment device 21 is communicated with a cavity between the side cover 2 and the wheel body 1, the other end of each oiling channel of the fine adjustment device is connected with the oiling channel of the dust cap 22, the other end of each oiling channel of the dust cap 22 is connected with an oiling one-way valve, the oiling channel of the dust cap 22 is connected with the oiling channel of the fine adjustment device 21, and the structure can realize post-maintenance on the bearing 3 or the sliding device 31 without disassembling the dust cap 22. The connection of the oiling one-way valve and the components can be welding or threaded connection.

The invention provides a carrier with a thrust wheel, in particular an excavator and a tank.

A side cover bearing mounting tool, as shown in figures 18 and 19,

scheme one:

and (3) a tool: including installation pull rod 32 and bearing pull nut 322, pull rod 32 and bearing pull nut 322 are the supporting structure of combination screw thread, the diameter of pull rod 32 is less than the internal diameter of fine setting screw 23, packs into side cap 2 with bearing 3, and bearing installation pull rod 32 screw in bearing 3 hole and fine setting screw 23, bearing installation pull rod 32 cover bearing pull nut 322, borrow the instrument to bearing pull nut 322's rotation pulls in side cap 2 with bearing 3, withdraws from bearing pull nut 322 to withdraw from both accomplishing the installation with installation pull rod 32.

Scheme II:

and (3) a tool: the device comprises a mounting push rod 33, wherein the threads of the mounting push rod 33 and the threads of the fine adjustment screw hole 23 are of a combined matching structure. A bearing 3 is arranged in the side cover 2, a bearing installation push rod 33 is screwed into an inner hole of the bearing 3 and is screwed into the fine adjustment screw hole 23, the bearing installation push rod 33 is rotated to push the bearing 3 into the side cover 2, and the installation push rod 33 is withdrawn to complete the installation.

The tool (1) the installation pull rod 32 or the installation push rod 33 and the pressure sheet 321 are integrated, or may be non-integrated, for example, the non-integrated structure, and the bearing installation pull rod 32 or the bearing installation push rod 33 should be sleeved with the pressure sheet 321; (2) the seal 12 is fitted to the side cover 2 or to the wheel body 1 before the side cover 2 is not mounted to the wheel axle 111.

A side cover installation tool, as shown in figures 20 and 21,

scheme one:

and (3) a tool: the side cover mounting screw comprises a side cover mounting screw 41 and a side cover pressure nut 413, wherein the threads of the side cover mounting screw 41 and the threads of the side cover mounting positioning screw hole 11 and the side cover pressure nut 413 are of a combined matched structure. The side cover 2 with the bearing 3 is sleeved on the wheel shaft 111 of the wheel body 1, after the side cover pressure nut 413 is screwed into the bottom of the side cover mounting screw 41, the side cover mounting screw 41 is screwed into the fine adjustment screw hole 23 to be locked on the side cover mounting positioning screw hole 11, after the side cover pressure nut 413 is rotated by a tool to press the side cover 2 into place, the mounting screw 41 is withdrawn, and thus the mounting is completed.

Scheme II:

and (3) a tool: the side cover mounting structure comprises side cover mounting screws 41, wherein the threads of the side cover mounting screws 41 and the threads of the side cover mounting positioning screw holes 11 are of a combined matching structure. The side cover 2 with the bearing 3 is sleeved on the wheel shaft 111 of the wheel body 1, the side cover mounting screw 41 is screwed into the fine adjustment screw hole 23 and locked on the side cover mounting positioning screw hole 11, and after the side cover 2 is pressed in place by means of the tool rotating mounting screw 41, the mounting screw 41 is withdrawn, so that the mounting is completed.

As shown in fig. 22 and 23,

and (3) a tool: the side cover withdrawing push rod 412 is included, and the threads of the side cover withdrawing push rod 412 and the threads of the fine adjustment screw hole 23 are of a combined matching structure. The fine adjustment device 21 is rotated in the direction of the wheel axle 111 based on the fine adjustment screw hole 23, and the wheel axle 111 or the slide device 31 is used to withdraw the side cover 2 from the wheel axle 111.

The side cover withdrawing push rod 412 is a fine adjustment device 21.

The diameter of the beginning end of the side cover withdrawing push rod 412 is smaller than the inner diameter of the side cover mounting positioning screw hole 11.

A method for assembling a thrust wheel, as shown in figures 18, 20 and 21,

the first step: a bearing 3 is arranged in the side cover 2, a bearing installation pull rod 32 penetrates through an inner hole of the bearing 3 and the fine adjustment screw hole 23, a bearing pull nut 322 is sleeved on the bearing installation pull rod 32, and the bearing 3 is pulled into the side cover 2 by rotating the bearing pull nut 322 through a tool;

and a second step of: repeating the first step to finish the loading of the other bearing 3 into the other side cover 2;

and a third step of: the side cover 2 with the bearing 3 is sleeved on the wheel shaft 111 of the wheel body 1, a side cover mounting screw 41 penetrates through the fine adjustment screw hole 23 to be locked on the side cover mounting positioning screw hole 11, the side cover 2 is pressed into place by means of tool rotation of the mounting screw 41, and then the mounting screw 41 is withdrawn;

fourth step: repeating the third step, assembling the other side cover 2 with the bearing 3 on the wheel axle 111 of the wheel body 1, and completing the assembly.

A method for assembling a thrust wheel, as shown in figures 19, 20 and 21,

the first step: a bearing 3 is arranged in the side cover 2, a bearing installation push rod 33 is screwed into the fine adjustment screw hole 23 through an inner hole of the bearing 3, the bearing 3 is pushed into the side cover 2 by rotating the bearing installation push rod 33, and the bearing installation push rod 33 is withdrawn;

And a second step of: repeating the first step on the other side cover 2 to load the other bearing 3;

and a third step of: the side cover 2 with the bearing 3 is sleeved on the wheel shaft 111 of the wheel body 1, the mounting screw 41 penetrates through the fine adjustment screw hole 23 to be locked on the side cover mounting positioning screw hole 11, the mounting screw 41 is rotated by a tool to press the side cover 2 into place, and then the mounting screw 41 is withdrawn;

In the assembly method of the two thrust wheels, the bearing mounting pull rod 32 or the bearing mounting push rod 33 and the pressure plate 321 are (1) integrated or non-integrated, such as non-integrated, and in the first step, the bearing mounting pull rod 32 or the bearing mounting push rod 33 should be sleeved with the pressure plate 321; (2) the seal 12 is fitted to the side cover 2 or to the wheel body 1 in a step prior to the side cover 2 being mounted on the wheel axle 111.

A method for adjusting a thrust wheel is shown in figure 4,

the first step: fixing the assembled thrust wheel to the carrier by means of the fixing screw holes 24;

and a second step of: after the fine adjustment device 21 rotates against the wheel axle 111, the fine adjustment device 21 moves back a distance in the opposite direction;

and a third step of: the two sides synchronously operate above, so that the bearing 3 does not have any play gap, but flexibly rotates to be standard.

An adjusting method of a thrust wheel is shown in figures 5-8,

and a second step of: after the fine adjustment device 21 rotates to push the sliding device 31 against the wheel axle 111, the fine adjustment device 21 moves back a distance in the opposite direction;

A method for adjusting a thrust wheel is shown in FIG. 13,

and a second step of: the fine adjustment device 21 rotates to push the elastic device 211 to the sliding device 31 to abut against the wheel axle 111;

According to the requirement, after the fine adjustment device 21 is adjusted, the joint of the fine adjustment device 21 and the fine adjustment screw hole 23 is coated with anti-loose glue, or a dustproof cap 22 is fastened outside the fine adjustment screw hole 23, and the dustproof cap 22 is propped against the fine adjustment device 21 at the same time, so that dust can be prevented and the fine adjustment device 21 can be prevented from loosening.

The carrier is as follows: and testing the tool table, the excavator, the tank and other objects under the operating conditions.

A method of dismounting a thrust wheel, as shown in figure 22,

the first step: rotating the fine adjustment device 21 in the direction of the axle 111 based on the fine adjustment screw hole 23, and withdrawing the side cover 2 from the axle 111 by means of the axle 111 or the sliding device 31;

and a second step of: the above operations are synchronized on both sides, so that the two side covers 2 are separated from the wheel body 1.

A method of dismounting a thrust wheel, as shown in figure 23,

the first step: based on the fine adjustment screw hole 23, the fine adjustment device 21 is withdrawn, a side cover withdrawing push rod 412 rotates towards the wheel axle 111 by means of the fine adjustment screw hole 23, and the side cover 2 is withdrawn from the wheel axle 111 by means of the bottom of the side cover mounting screw hole;

Fig. 24 to 28 are CAD drawings drawn by the production of the present invention, and are brief descriptions of the floor-standing production of the present application.

The foregoing has outlined rather broadly the more detailed description of embodiments of the invention, wherein the principles and embodiments of the invention are explained in detail using specific examples, the above examples being provided solely to facilitate the understanding of the method and core concepts of the invention; meanwhile, as those skilled in the art will have variations in the specific embodiments and application scope in accordance with the ideas of the present invention, the present description should not be construed as limiting the present invention in view of the above.

Claims

1. A wheel body is characterized in that,

the wheel body (1) comprises: the guide rails (120) and the wheel shafts (111), the guide rails (120) around the two sides of the wheel body (1) and the wheel shafts (111) in the centers of the two sides of the wheel body (1) are integrally formed with the wheel body (1); and a supporting seat (112) formed by a concave cavity formed by integral molding is arranged between the guide rail (120) and the wheel axle (111).

2. A side cover is characterized in that,

the side cover (2) includes: the bearing seat (262) and the fixing seat (242) and the connecting part (252) for connecting the bearing seat (262) and the fixing seat (242), and the bearing seat (262), the fixing seat (242) and the connecting part (252) are integrally formed;

the fixing seat (242) is provided with at least one fixing screw hole (24) for screw fastening.

3. A thrust wheel is characterized in that,

comprising the claims 1 and 2.

4. A thrust wheel is characterized in that,

comprising the structure of claim 3, wherein the two side covers (2) are respectively arranged in the supporting seat (112);

the bearing (3) is supported between the outer peripheral surface of the wheel shaft (111) and the inner wall of the bearing seat (262), and the chain moves in the guide rail (120) to drive the wheel body (1) and the wheel shaft (111) to synchronously rotate on the inner ring (302) of the bearing (3), so that the rotation of the inner ring (302) of the bearing is realized, and the outer ring (301) does not rotate.

5. Wheel or thrust wheel according to claim 1 or 3, 4, characterized in that the inside of the support (112) is a first stop means (113).

6. A side cover or roller according to claim 2 or 3 or 4, wherein the bearing seat (262) extends inwardly by a second stop means (263).

7. The thrust wheel according to claim 4, wherein the inner ring (302) of the bearing (3) is limited between the first limiting device (113) and the outer ring (301) is limited between the second limiting device (263).

8. The wheel according to claim 5, wherein the first stop means (113) extends from the inner ring (302) of the bearing 3 in the direction of the outer ring (301) and does not touch the outer ring (301) at maximum.

9. The side cover according to claim 6, characterized in that the second stop means (263) extends from the outer ring (301) of the bearing (3) in the direction of the inner ring (302), at the longest without touching the inner ring (302).

10. A wheel or side cover according to claim 5 or claim 6, wherein the first and second stop means are of roughened or textured design.

11. The wheel body or the thrust wheel according to claim 1, 3 and 4, wherein side surface centers of two ends of the wheel axle (111) are also provided with side cover installation positioning screw holes (11), and the screw holes are of internal thread structures.

12. A side cover or thrust wheel according to claim 2 or 3, 4, characterized in that the side cover (2) is provided with fine tuning screw holes (23) for mounting bearings (3), said screw holes being of internal thread construction.

13. Wheel or thrust wheel according to claim 1 or 3, 4, characterized in that the axial length of the axle (111) is smaller than or equal to the axial length of the wheel (1).

14. A thrust wheel with a fine adjustment device is characterized in that,

comprising a composition according to claim 12,

further comprises a fine adjustment device (21) for adjusting the axial displacement of the wheel axle (111),

the fine adjustment device (21) is screwed into the fine adjustment screw hole (23),

the fine adjustment device (21) is abutted against the wheel shaft (111).

15. A thrust wheel with a self-adaptive fine adjustment device is characterized in that,

comprising a composition according to claim 3 or 4,

also comprises elastic means (211) for adjusting the axial displacement of the axle (111),

the sliding device (31) is propped against the space between the wheel axle (111) and the elastic device (211), and the other end of the elastic device (211) is propped against the inside of the side cover (2).

16. The thrust wheel of claim 14, wherein the thrust wheel comprises,

also comprises a sliding device (31),

the sliding device (31) is arranged between the propped wheel axle (111) and the fine adjustment device (21).

17. The thrust wheel according to claim 14, wherein the center points of the fine adjustment device (21), the fine adjustment screw hole (23) and the wheel shaft (111) are at the same level.

18. The thrust wheel according to claim 14, characterized in that the thread of the fine adjustment means (21) is combined with the thread of the fine adjustment screw hole (23).

19. The thrust wheel according to claim 14 or 15, characterized in that the sliding means (31) are: ball, needle bearing, pressure ball bearing, stopper.

20. A thrust wheel according to claim 14 or 15, wherein the axle (111) has an outwardly extending valve seat (312), the sliding means (31) being fitted over the outer diameter of the valve seat (312); alternatively, the axle (111) has an inward valve seat, and the sliding device (31) is sleeved in the inner diameter of the valve seat.

21. The thrust wheel of claim 15, wherein the thrust wheel comprises,

further comprises a fine adjustment device (21),

the side cover (2) is provided with a fine adjustment screw hole (23), the fine adjustment device (21) is screwed into the fine adjustment screw hole (23), and the fine adjustment device (21) abuts against the elastic device (211).

22. The thrust wheel of claim 16, wherein the thrust wheel comprises,

the device also comprises a pressure disc (311), wherein the pressure disc (311) is arranged between the sliding device (31) and the fine adjustment device (21); or, the pressure disc (311) is arranged between the sliding device (31) and the elastic device (211).

23. The thrust wheel of claim 16, wherein the thrust wheel comprises,

the device further comprises an elastic device (211), wherein the elastic device (211) is arranged between the sliding device (31) and the fine adjustment device (21).

24. A thrust wheel with a sealing device is characterized in that,

comprising the composition of claim 3 or 4 or 14 or 15,

the wheel body (1) is provided with a seat for installing the sealing element (12) at the joint of the side cover (2) and the wheel body (1), and the seat is a groove for installing the sealing element (12).

25. A thrust wheel with a sealing device is characterized in that,

comprising the composition of claim 3 or 4 or 14 or 15,

the side cover (2) is provided with a seat for installing the sealing element (12) at the joint of the side cover (2) and the wheel body (1), and the seat is a groove for installing the sealing element (12).

26. The sealing arrangement according to claim 24 or 25, characterized in that the outer ring of the seal (12) is an interference fit with the groove.

27. A thrust wheel with a oiling device is characterized in that,

comprising any of the claims 3, 4 or 14, 15, 24, 25,

the utility model also comprises a side cover (2) provided with an oil adding channel.

28. A thrust wheel with a oiling device is characterized in that,

comprising any of the claims 3, 4 or 14, 15, 24, 25,

the dust cap (22) is also provided with an oil adding passage.

29. A thrust wheel with a oiling device is characterized in that,

comprising any of the claims 3, 4 or 14, 15, 24, 25,

The device also comprises a fine adjustment device (23) provided with an oil adding passage.

30. A roller according to claim 27 or 28 or 29, wherein one end of the oiling channel opens into a cavity between the side cover (2) and the wheel body (1).

31. A roller according to claim 27 or 28 or 29, wherein a one-way valve is mounted at the other end of the oil gallery.

32. A thrust wheel according to claim 29, wherein the oiling channel of the fine adjustment device (23) communicates with the oiling channel of the dust cap (22).

33. The thrust wheel of claim 14 or 28, 29, further comprising a dust cap (22), the dust cap (22) being fastened to the outside of the fine adjustment device (21) in engagement with the fine adjustment device (21).

34. An excavator comprising a bogie as claimed in any one of claims 4, 14, 15, 24, 25, 27, 28, 29.

35. A tank comprising a bogie wheel according to any one of claims 4, 14, 15, 24, 25, 27, 28, 29.

36. A side cover bearing installation tool is characterized in that,

comprising a composition according to claim 3 or 4,

the device comprises a pull rod (32) and a bearing tension nut (322), wherein the pull rod (32) and the bearing tension nut (322) are of a combined thread matching structure, and the diameter of the pull rod (32) is smaller than the inner diameter of a fine adjustment screw hole (23).

37. A side cover bearing installation tool is characterized in that,

comprising a composition according to claim 3 or 4,

the device comprises a mounting push rod (33), wherein the threads of the mounting push rod (33) and the threads of the fine adjustment screw hole (23) are of a combined matched structure.

38. The side cover bearing mounting tool according to claim 36 or 37, wherein the mounting tie rod (32) or the mounting push rod (33) is of unitary construction with the pressure plate (321).

39. A side cover installation tool is characterized in that,

comprising a composition according to claim 1,

the novel side cover mounting structure comprises side cover mounting screws (41) and side cover pressure nuts (413), wherein the threads of the side cover mounting screws (41) and the threads of the side cover mounting positioning screw holes (11) and the side cover pressure nuts (413) are of a combined matched structure.

40. A side cover installation tool is characterized in that,

comprising a composition according to claim 1,

the novel side cover mounting structure comprises side cover mounting screws (41), wherein the threads of the side cover mounting screws (41) and the threads of the side cover mounting positioning screw holes (11) are of a combined matching structure.

41. A side cover dismounting tool is characterized in that,

comprising a composition according to claim 3 or 4,

the side cover withdrawing push rod (412) is included, and the threads of the side cover withdrawing push rod (412) and the threads of the fine adjustment screw hole (23) are of a combined matching structure.

42. The side cover removing tool according to claim 41, wherein said side cover withdrawing push rod (412) is a fine adjustment device (21).

43. The side cover removing tool according to claim 41, wherein a start end diameter of said side cover withdrawing push rod (412) is smaller than an inner diameter of said side cover mounting positioning screw hole (11).

44. A method for adjusting a thrust wheel is characterized in that,

comprising a thrust wheel according to claim 12,

the first step: fixing the assembled thrust wheel on a carrier by means of fixing screw holes (24);

and a second step of: after the fine adjustment device (21) rotates to prop against the wheel shaft (111), the fine adjustment device (21) moves back a certain distance in the opposite direction;

and a third step of: the two sides synchronously operate, so that the bearing (3) does not have any play gap, but flexibly rotates to be standard.

45. A method for adjusting a thrust wheel is characterized in that,

comprising a thrust wheel according to claim 14,

and a second step of: after the fine adjustment device (21) rotates to push the sliding device (31) to prop against the wheel shaft (111), the fine adjustment device (21) moves back a certain distance in the opposite direction;

46. A method for adjusting a thrust wheel is characterized in that,

comprising a thrust wheel according to claim 21,

and a second step of: the fine adjustment device (21) rotates to push the elastic device (211) to the sliding device (31) to prop against the wheel shaft (111);

47. A method of adjusting a thrust wheel according to any one of claims 44 to 46, wherein a dust cap (22) is fastened to the outside of the fine adjustment screw (23), the dust cap (22) simultaneously being pressed against the fine adjustment device (21).

48. A method for disassembling a thrust wheel is characterized in that,

comprising a thrust wheel according to claim 12,

the first step: rotating the fine adjustment device (21) in the direction of the wheel axle (111) based on the fine adjustment screw hole (23), and withdrawing the side cover (2) from the wheel axle (111) by means of the wheel axle (111) or the sliding device (31);

and a second step of: the two sides synchronously operate to separate the two side covers (2) from the wheel body (1).

49. A method for disassembling a thrust wheel is characterized in that,

comprising a thrust wheel according to claim 12,

the first step: the side cover withdrawing push rod (412) withdraws from the fine adjustment device (21) on the basis of the fine adjustment screw hole (23), and the side cover withdrawing push rod (412) rotates towards the wheel shaft (111) by means of the fine adjustment screw hole (23), so that the side cover (2) withdraws from the wheel shaft (111) by means of the bottom of the side cover mounting screw hole;