CN111005947A

CN111005947A - Hydraulic wheel hub

Info

Publication number: CN111005947A
Application number: CN201911381815.8A
Authority: CN
Inventors: 陈伟; 高冠华
Original assignee: Beijing Baska Technology Co ltd
Current assignee: Beijing Baska Technology Co ltd
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2020-04-14

Abstract

The application discloses hydraulic pressure wheel hub contains: the hydraulic pressure device comprises a shaft sleeve, a hydraulic pressure cavity and a pressure sensor, wherein the shaft sleeve is provided with a hydraulic pressure cavity, and a pressure medium is injected into the hydraulic pressure cavity; the shaft sleeve is sleeved on the rotating shaft; the pressure release valve is fixedly connected with the shaft sleeve and communicated with the hydraulic cavity; the pressure release valve extends out of a pressure lever in the axial direction of the rotating shaft, and the pressure lever can move in the axial direction and is used for opening the pressure release valve; the end cover is provided with a sliding groove close to the axial side face of the shaft sleeve, the sliding groove is used for accommodating the end part of the pressure lever, and the end cover is fixedly connected with the rotating shaft; after the shaft sleeve and the rotating shaft slide relatively in the circumferential direction, the end part of the pressure lever slides out of the sliding groove, the pressure relief valve is opened, and the pressure medium in the hydraulic cavity is released. The beneficial effects of this application lie in the pressure medium in the hydraulic pressure cavity release back, need not change any spare part, safe and reliable can promote work efficiency.

Description

Hydraulic wheel hub

Technical Field

The application relates to the technical field of couplings, in particular to a hydraulic hub.

Background

Conventional couplings primarily transfer torque by means of various keyed connections. For devices that transmit relatively large amounts of torque, keyways in the shaft can severely weaken the strength, stiffness, and load carrying capability of the shaft. Increasing the radius of the shaft increases the size of the entire device, which makes the device bulky and heavy, and increases the production cost, and the radial size of the shaft alone does not provide a desirable effect. In addition, the large-scale coupling is required to be capable of stably operating for a long time in the working process. In order to ensure the concentricity of the two connected shafts and avoid vibration, the general large-scale coupling and the shafts are in over fit or interference fit. The mounting and dismounting of such couplings is difficult. The coupling with smaller size can be assembled with the shaft by means of mechanical striking or pushing, but the inner wall of the sleeve of the coupling and the shaft are often pulled to be damaged in the assembling process, and the large coupling cannot be assembled at all by means of mechanical striking.

The advent of hydraulic couplings solved these problems. By injecting a hydraulic medium into a sandwiched sleeve and then pressing the medium with a screw/piston or an external working pump, the pressure can be dispersed and uniformly transmitted to the contact surface of the shaft and the hub (or other components connected with the shaft), and the sandwiched sleeve expands uniformly around the shaft, thereby generating uniform contact pressure. Compared with a coupler connected by a common traditional key, the hydraulic coupler has the advantages of more compact structure, quicker installation and disassembly, easier positioning, no damage to a joint surface and more convenience in disassembly and assembly.

However, the hub and the mounting shaft of the hydraulic coupling adopt a keyless connection mode, and torque is transmitted by means of friction force between the joint surfaces. When the transmission system is in an abnormal working condition, the system is overloaded, the coupling and the shaft cannot be disconnected in time, the joint surfaces of the hub and the mounting shaft of the coupling slide relatively, and the inner hole of the hub and the transmission system are easily damaged. The problem of above-mentioned hydraulic coupling is solved to prior art is that the shear valve of intercommunication hydraulic medium is installed to the wheel hub, and when wheel hub and installation axle take place relative slip, the shear valve is sheared, and the hydraulic medium in the wheel hub is released, appears the clearance between wheel hub hole and the installation axle. Although this kind of scheme has solved the risk that wheel hub and installation axle damaged, and the shear valve shears the back, need change again, work efficiency is low, also requires higher to the personnel.

Disclosure of Invention

It is an object of the present application to provide a hydraulic hub that overcomes or at least alleviates at least one of the above-mentioned disadvantages of the prior art.

To achieve the above object, the present application provides a hydraulic hub, comprising:

the hydraulic pressure device comprises a shaft sleeve, a hydraulic pressure cavity and a pressure sensor, wherein the shaft sleeve is provided with a hydraulic pressure cavity, and a pressure medium is injected into the hydraulic pressure cavity; the shaft sleeve is sleeved on the rotating shaft;

the pressure release valve is fixedly connected with the shaft sleeve and communicated with the hydraulic cavity; the pressure release valve extends out of a pressure lever in the axial direction of the rotating shaft, and the pressure lever can move in the axial direction and is used for opening the pressure release valve;

the end cover is provided with a sliding groove close to the axial side face of the shaft sleeve, the sliding groove is used for accommodating the end part of the pressure lever, and the end cover is fixedly connected with the rotating shaft;

after the shaft sleeve and the rotating shaft slide relatively in the circumferential direction, the end part of the pressure lever slides out of the sliding groove, the pressure relief valve is opened, and the pressure medium in the hydraulic cavity is released.

Preferably, the pressure relief valve comprises:

the valve body is fixedly connected with the shaft sleeve in a detachable mode, an axial through hole is formed in the center of the valve body, and a one-way valve structure is arranged at one end of the axial through hole;

the pressure lever is arranged at the other end of the axial through hole, one end of the pressure lever extends out of the axial end face of the valve body, and the other end of the pressure lever is used for enabling the one-way valve structure to be in an open state when the pressure lever moves.

Preferably, the axial through hole comprises three sections, wherein one section is provided with a threaded hole at the end part, the other two sections are provided with unthreaded holes, the diameter of the unthreaded hole at the middle section is larger than that of the unthreaded hole at the other section, and the two sections of unthreaded holes are excessively connected through a conical surface;

the pressure release valve also comprises a compression spring, a screw plug and a sealing body;

the screw plug is arranged at the threaded hole, and a through hole is formed in the center of the screw plug;

the sealing body is arranged in the unthreaded hole in the middle section, is in contact with the conical surface and is used for sealing the axial through hole in the center of the valve body;

one end of the compression spring is abutted against the sealing body, and the other end of the compression spring is abutted against the end face of the screw plug;

and when the compression rod moves axially, pressure is applied to the sealing body so as to overcome the force of the compression spring and enable the axial through hole in the center of the valve body to be turned from a closed state to an open state.

Preferably, the sealing body is a steel ball.

Preferably: the valve body is fixedly connected with the shaft sleeve through threads; the valve body is characterized in that an even number of blind holes are uniformly distributed on the circumference of the end face of the valve body and used for inserting an installation tool so as to screw the valve body.

Preferably, one end of the pressure rod, which extends out of the valve body, is provided with a ball head, and the ball head is arranged in a sliding groove in the end cover.

Preferably, the pressure relief valves are uniformly distributed in the circumferential direction of the shaft sleeve.

Preferably, the sliding groove is an arc-shaped sliding groove, the axis of the arc-shaped sliding groove coincides with the axis of the end cover, and the axial depth of the arc-shaped sliding groove decreases progressively from the middle part to the two ends in the circumferential direction.

Preferably, the shaft sleeve is provided with a connecting flange at one end far away from the end cover, and the connecting flange is used for being connected with another hub to form a coupler.

Preferably, a shaft rolling bearing is mounted between the shaft sleeve and the rotating shaft.

Compared with the prior art, the method has the following beneficial effects:

the utility model provides a hydraulic pressure wheel hub is provided with the hydrovalve, be provided with the depression bar on the relief valve, the one end of depression bar sets up in the spout on the end cover, hydraulic pressure axle sleeve installs on the rotation axis, a transmission torque, and end cover and rotation axis fixed connection, after hydraulic pressure wheel hub takes place to transship, relative rotation takes place in the circumferencial direction between axle sleeve and the rotation axis, the slide out in the spout is certainly to the depression bar, axial displacement takes place, and then open the relief valve, make the release of pressure medium in the axle sleeve, the clearance appears between axle sleeve and the rotation axis, can effectively prevent because of the wearing and tearing that.

In addition, hydraulic pressure wheel hub of this application need not change any spare part again after the pressure release, only needs rotatory wheel hub, makes in the depression bar reentrants the spout on the end cover, and the closing state is replied to the relief valve promptly, injects pressure medium again this moment, can realize the locking of axle sleeve and rotation axis. Compared with the safety shear valve structure in the existing structure, the pressure in the shaft sleeve can be released only after the shear valve is sheared, and the shear valve needs to be replaced again after the pressure is released; the technical scheme that this application provided has work efficiency height, requires low advantage to staff's technical merit.

Thirdly, when releasing the pressure medium in the shaft sleeve, the hydraulic hub provided by the application is safe and reliable, and the pressure medium is axially discharged. In the prior art, radial discharge exists, so that certain potential safety hazards exist;

drawings

Fig. 1 is a schematic structural diagram of a hydraulic hub according to an embodiment of the present application.

Fig. 2 is a schematic structural view of a relief valve of the hydraulic hub shown in fig. 1.

FIG. 3 is a schematic structural view of an end cover of the hydraulic hub illustrated in FIG. 1.

FIG. 4 is a schematic view of another orientation of the end cap of the hydraulic hub illustrated in FIG. 1.

Fig. 5 is a schematic sectional view taken along line B-B in fig. 4.

Fig. 6 is a schematic sectional view taken along line a-a in fig. 4.

Wherein, 1-shaft sleeve; 12-a connecting flange; 2-a pressure relief valve; 21-a pressure bar; 22-a valve body; 23-a compression spring; 24-a plug screw; 25-a seal; 3-end cover; 31-chute.

Detailed Description

In order to make the implementation objects, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the drawings in the embodiments of the present application. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are a subset of the embodiments in the present application and not all embodiments in the present application. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present application and should not be construed as limiting the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application. Embodiments of the present application will be described in detail below with reference to the accompanying drawings.

In the description of the present application, it is to be understood that the terms "central," "longitudinal," "lateral," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientation or positional relationship indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated in a particular manner and are not to be considered limiting of the scope of the present application.

Referring to fig. 1 to 6, a hydraulic hub includes a shaft sleeve 1, a pressure relief valve 2 and an end cover 3.

The shaft sleeve 1 comprises an outer sleeve and an inner sleeve, the radial thickness of the outer sleeve is larger than that of the inner sleeve, and an inner hole of the outer sleeve is matched with the outer circle of the inner sleeve to form a hydraulic cavity 11. An oil inlet nozzle and an oil drainage nozzle are arranged on the outer sleeve and are respectively communicated with the hydraulic cavity 11, and the oil inlet nozzle is used for injecting pressure medium into the hydraulic cavity 11; the oil drain nozzle is used for releasing pressure media in the hydraulic cavity 11 when the hub is disassembled. The shaft sleeve 1 is sleeved on the rotating shaft, and when pressure media are injected into the hydraulic cavity 11 through the external pump, the inner layer sleeve shrinks and deforms, so that the shaft sleeve and the rotating shaft are locked. It will be appreciated that the pressure medium may be a thin oil, such as a hydraulic oil, or a glycerol, such as grease. When the shaft sleeve is used for a rotating shaft rotating at a low speed, the pressure medium can be lubricating grease, and the lubricating grease has the advantage of poor fluidity and is more beneficial to sealing. When the shaft sleeve is used for a rotating shaft rotating at a high speed, the pressure medium can adopt thin oil, and the thin oil has the advantages of good fluidity, and can be instantly released in a short time when hydraulic oil in the hydraulic cavity 11 needs to be released, so that the abrasion between the shaft sleeve and the rotating shaft is reduced to the minimum.

The pressure release valve 2 is fixedly connected with the shaft sleeve 1 and communicated with the hydraulic cavity 11; the pressure relief valve 2 extends with a pressure lever 21 in the axial direction of the rotating shaft, and the pressure lever 21 can move axially for opening the pressure relief valve 2. In the embodiment, the pressure release valve 2 is fixedly connected with the shaft sleeve 1 through threads, an axial threaded hole is formed in an outer-layer sleeve of the shaft sleeve 1, and the threaded hole is communicated with the hydraulic cavity 11; the pressure release valve 2 is provided with the external screw thread, and the pressure release valve 2 is provided with sealing end face, be provided with sealed the pad between sealing end face and the axle sleeve 1, sealed the pad be used for sealing the connecting thread of pressure release valve 2 and axle sleeve, prevent that the pressure medium in the hydraulic chamber 11 from following connecting thread department reveals. In this embodiment, the sealing pad is a copper pad.

It will be appreciated that the pressure relief valve 2 may also be fixedly connected to the sleeve 1 by screws. For example, in an alternative embodiment, one end of the pressure relief valve 2 is provided with a mounting flange, a mounting counter bore of the flange is arranged on the shaft sleeve 1 correspondingly, the mounting flange of the pressure relief valve is provided with a screw hole for a screw to pass through, and a threaded blind hole is arranged on the shaft sleeve 1 correspondingly and used for mounting the screw; in a similar way, by adopting the structure, the sealing gasket is also arranged between the mounting flange of the pressure release valve 2 and the axial matching surface of the shaft sleeve 1.

The axial side surface of the end cover 3 close to the shaft sleeve 1 is provided with a sliding groove 31, the sliding groove 31 is used for accommodating the end part of the pressure lever 21, and the end cover 3 is fixedly connected with the rotating shaft; when the rotating shaft is provided with a key groove, the end cover 3 and the rotating shaft can be connected through a key; when the rotating shaft is an optical axis, the end cover 3 may be provided with a set screw in a radial direction, and the fixed connection between the end cover 3 and the rotating shaft is realized through the set screw.

Under the normal working condition of the hydraulic hub, the pressure release valve 2 is in a normally closed state, and the hydraulic hub can normally transmit torque. When overload or impact occurs, if overload force or impact force exceeds hydraulic locking force between the shaft sleeve 1 and the rotating shaft, relative sliding occurs between the shaft sleeve 1 and the rotating shaft in the circumferential direction, at the moment, the end part of the pressure rod 21 slides out of the sliding groove 31, the pressure rod 21 moves axially, the pressure release valve 2 is opened, and pressure media in the hydraulic cavity 11 are released.

The hydraulic hub has the advantages that when overload protection is carried out on the hydraulic hub, no damaged part is arranged on the hydraulic hub, so that the hydraulic hub does not need to be disassembled, replaced and the like, and spare parts do not need to be stored. When the hydraulic hub is required to recover the function of transmitting torque again, the hydraulic hub is only required to be rotated, so that the end part of the pressure rod 21 slides into the chute again, and the pressure release valve 2 can be closed. At this time, pressure medium can be injected into the hydraulic cavity 11 again through the oil inlet nozzle, and the rotating shaft is locked, so that the hydraulic hub starts to transmit torque again.

In the present embodiment, the center of the valve body 22 is provided with an axial through hole, and one end of the axial through hole is provided with a one-way valve structure; the pressure lever 21 is arranged at the other end of the axial through hole, one end of the pressure lever extends out of the axial end face of the valve body 22, and the other end of the pressure lever is used for enabling the one-way valve structure to be in an open state when the pressure lever 21 moves. It will be understood that one end and the other end of the axial through hole are not limited to the end portions, but are relative.

The axial through hole comprises three sections, wherein one section is provided with a threaded hole at the end part, the other two sections are provided with unthreaded holes, namely, one end of the axial through hole is provided with the threaded hole, the other end opposite to the threaded hole is provided with the unthreaded hole, the section positioned in the middle is still provided with the unthreaded hole, the diameter of the unthreaded hole at the middle section is larger than that of the unthreaded hole at the other section, and the two sections of unthreaded holes are excessively connected through a conical surface.

The relief valve 2 further includes a compression spring 23, a plug screw 24, and a seal body 25.

The plug screw 24 is installed at the threaded hole, and a through hole is formed in the center of the plug screw for allowing the pressure medium in the hydraulic chamber 11 to pass through.

The sealing body 25 is arranged in the unthreaded hole in the middle section, is in contact with the conical surface and is used for sealing the axial through hole in the center of the valve body. In this embodiment, the sealing body 25 is a steel ball, and the steel ball is engaged with the conical surface to form a seal. It will be appreciated that the sealing body 25 may also be configured as an external cone, and the conical surface of the external cone is matched with the internal conical surface connecting the two segments of the light holes to form a conical surface seal.

One end of the compression spring 23 is pressed against the sealing body 25, and the other end is pressed against the end face of the screw plug 24; in an initial state, the compression spring is compressed, and the spring force pushes the steel ball against the inner conical surface to form sealing; when the pressure rod 21 is pressed, the pressure rod moves rightwards, the compression spring is further compressed through the steel ball, at the moment, the steel ball is separated from the inner conical surface, and the pressure medium in the hydraulic cavity 11 can flow out through the central through hole of the pressure release valve. It should be understood that the installation of the pressure rod 21 and the valve body 22 in fig. 2 is only a schematic structural diagram, and actually, the engagement of the pressure rod 21 and the valve body 22 is a large clearance fit, which aims to smoothly circulate the pressure medium. Or, a plurality of flow channels are arranged on the axial surface of the pressure rod 21 or the unthreaded hole section of the valve body 22 where the pressure rod 21 is installed along the axial direction of the pressure rod, so that the pressure medium in the hydraulic cavity 11 can flow out conveniently; still alternatively, an axial through hole may be provided in the center of the pressing rod 21. In the present embodiment, the compression spring 23 is a cylindrical compression spring, and it is understood that the compression spring may be a disc spring.

When the pressure rod 21 moves axially, pressure is applied to the sealing body 25 to overcome the force of the compression spring, so that the axial through hole in the center of the valve body is turned from a closed state to an open state.

In the present embodiment, an even number of blind holes 221 are uniformly distributed on the circumference of the end surface of the valve body 22, and the blind holes 221 are used for inserting an installation tool to screw the valve body. The valve has the advantages that the radial size of the valve body 22 can be reduced, the thickness requirement of the outer sleeve is further reduced, the requirement that the same type meets a plurality of apertures under the fixed overall dimension is met, and the shaft sleeve is more universal.

In this embodiment, the end of the pressure rod 21 extending out of the valve body 22 is provided with a ball head, and the ball head is arranged in a sliding groove on the end cover. The advantage is that the ball head is more beneficial to smooth sliding in the chute 31.

The pressure release valves 2 are uniformly distributed in the circumferential direction of the shaft sleeve 1, correspondingly, the end covers 3 are provided with a plurality of sliding grooves 31, the purpose is that pressure media in the hydraulic cavity 11 can be released in a short time, and the joint surface of the inner hole of the shaft sleeve 1 and the joint surface of the installation shaft is guaranteed not to be abraded to the maximum extent.

In this embodiment, as shown in fig. 3 to 6, the slide groove 31 is provided as an arc-shaped slide groove, the axis of the arc-shaped slide groove coincides with the axis of the end cover (fig. 4), the axial depth of the arc-shaped slide groove decreases from the middle to both ends in the circumferential direction (fig. 6), and the depth of the arc-shaped slide groove in the arc-shaped radial direction decreases from the middle to both sides (fig. 5).

It is understood that the arc chute may be provided in other forms. For example, in an alternative embodiment, the width of the arc-shaped sliding chute is greater than the diameter of the ball head at the end of the pressure rod, the axis of the arc-shaped sliding chute is perpendicular to the axis of the end cover 3, the length direction of the arc-shaped sliding chute is perpendicular to the axial direction of the end cover 3, and the depth of the arc-shaped sliding chute in the axial direction of the end cover 3 decreases from the middle to both sides uniformly.

The end of the shaft sleeve 1 far away from the end cover 3 is provided with a connecting flange 12, and different structures can be arranged on the connecting flange 12 according to requirements so as to be connected with another hub to form a coupler. For example, the connecting flange may be provided with a bolt connecting hole, a pin hole, a tooth, and the like to form a hub of a rigid coupling, a hub of an elastic pin coupling, a hub of an elastic sleeve pin coupling, a hub of an elastic pin gear coupling, a hub of a crowned gear coupling, a hub of a serpentine spring coupling, a hub of a diaphragm coupling, a hub of a quincunx coupling, and the like, and the two hubs form two half hubs of the whole coupling.

It is understood that when the rotational shaft to which the sleeve is attached is rotated at a high speed, the linear velocity is more than 5m/s, and that rolling bearings may be installed between the sleeve 1 and the rotational shaft, the rolling bearings being provided at both axial ends of the sleeve 1. To avoid wear between the inner bore of the sleeve 1 and the mounting shaft.

Finally, it should be pointed out that: the above examples are only for illustrating the technical solutions of the present application, and are not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.

Claims

1. A hydraulic hub, comprising:

the hydraulic pressure pump comprises a shaft sleeve (1), wherein a hydraulic cavity (11) is arranged on the shaft sleeve, and a pressure medium is injected into the hydraulic cavity (11); the shaft sleeve (1) is sleeved on the rotating shaft;

the pressure release valve (2), the pressure release valve (2) is fixedly connected with the shaft sleeve (1) and is communicated with the hydraulic cavity (11); the pressure relief valve extends out of a pressure lever (21) in the axial direction of the rotating shaft, and the pressure lever (21) can axially move and is used for opening the pressure relief valve (2);

the end cover (3), the axial side face of the end cover (3) close to the shaft sleeve (1) is provided with a sliding groove (31), the sliding groove (31) is used for accommodating the end part of the pressure lever (21), and the end cover (3) is fixedly connected with the rotating shaft;

after the shaft sleeve (1) and the rotating shaft slide relatively in the circumferential direction, the end part of the pressure lever (21) slides out of the sliding groove (31), the pressure release valve (2) is opened, and the pressure medium in the hydraulic cavity (11) is released.

2. A hydraulic hub according to claim 1, wherein the pressure relief valve (2) comprises:

the valve body (22), the valve body (22) and the shaft sleeve (1) are fixedly connected in a detachable mode, an axial through hole is formed in the center of the valve body (22), and a one-way valve structure is arranged at one end of the axial through hole;

the pressure lever (21) is arranged at the other end of the axial through hole, one end of the pressure lever extends out of the axial end face of the valve body, and the other end of the pressure lever is used for enabling the one-way valve structure to be in an open state when the pressure lever moves.

3. The hydraulic hub of claim 2, wherein the axial through-hole comprises three sections, wherein one section is provided with a threaded hole at an end portion, the other two sections are provided with unthreaded holes, the diameter of the unthreaded hole of the middle section is larger than that of the unthreaded hole of the other section, and the two sections of unthreaded holes are excessively connected through a conical surface;

the pressure relief valve also comprises a compression spring (23), a screw plug (24) and a sealing body (25);

the screw plug (24) is arranged at the threaded hole, and a through hole is formed in the center of the screw plug;

the sealing body (25) is arranged in the unthreaded hole in the middle section, is in contact with the conical surface and is used for sealing the axial through hole in the center of the valve body;

one end of the compression spring (23) is abutted against the sealing body, and the other end of the compression spring is abutted against the end face of the screw plug;

when the compression rod (21) moves axially, pressure is applied to the sealing body (25) so as to overcome the force of the compression spring and enable the axial through hole in the center of the valve body to be turned from a closed state to an open state.

4. A hydraulic hub as claimed in claim 3, wherein said seal is a steel ball.

5. A hydraulic hub as claimed in claim 4, wherein: the valve body (22) is fixedly connected with the shaft sleeve (1) through threads; the end face circumference of the valve body (22) is uniformly provided with an even number of blind holes, and the blind holes are used for inserting an installation tool to screw the valve body.

6. A hydraulic hub as claimed in claim 5, wherein: one end of the pressure lever (21) extending out of the valve body is provided with a ball head, and the ball head is arranged in a sliding groove in the end cover.

7. A hydraulic hub as claimed in claim 6, wherein: the pressure release valves (2) are uniformly distributed in the circumferential direction of the shaft sleeve (1) in a plurality.

8. A hydraulic hub as claimed in claim 7, wherein: the sliding groove (31) is an arc-shaped sliding groove, the axis of the arc-shaped sliding groove coincides with the axis of the end cover, and the axial depth of the arc-shaped sliding groove decreases progressively from the middle part to the two ends in the circumferential direction.

9. A hydraulic hub as claimed in claim 8, wherein: the shaft sleeve (1) is provided with a connecting flange (12) at one end far away from the end cover, and the connecting flange is used for being connected with another hub to form a coupler.

10. A hydraulic hub as claimed in claim 9, wherein: and a shaft rolling bearing is arranged between the shaft sleeve (1) and the rotating shaft.