Oil pressure locking device

Abstract

The invention discloses an oil pressure locking device which is used for braking a shaft core of an electric spindle, the oil pressure locking device comprises a flange assembly and a braking assembly, the flange assembly can be assembled on a front bearing seat of the electric spindle and is arranged on the periphery of the shaft core in a sleeving mode, and a first gap is formed between the flange assembly and the shaft core; the flange assembly is provided with a containing cavity, a first through hole communicating with the containing cavity and the first gap, and an oil way communicating with the containing cavity and located on the side, away from the first gap, of the containing cavity. The brake assembly is arranged in the containing cavity and the first through hole, and hydraulic oil in the oil way can drive the brake assembly to partially move into the first gap in the extending direction of the first through hole so as to abut against the periphery of the shaft core. The hydraulic oil can extrude the brake assembly towards the direction of the shaft core, the brake assembly located in the containing cavity deforms into the first through hole to extrude or drive the brake assembly located in the first through hole to enter the first gap and abut against the periphery of the shaft core, and therefore rapid braking of the shaft core during power failure is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of shaft core braking, and in particular to a hydraulic locking device. Background Art

[0002] The electric spindle consists of a spindle, bearings, a spindle unit housing, a drive module, and a cooling device. The motor rotor is press-fitted into one piece with the spindle, and the spindle is supported by front and rear bearings. The motor stator is installed in the spindle unit housing through a cooling sleeve. The spindle speed is controlled by the spindle drive module, and the temperature rise in the spindle unit is limited by the cooling device. The shaft core runs when the power is on, and the shaft core slows down and stops running when the power is off. However, the shaft core will still run for a period of time when the power is off, which is dangerous.

[0003] Therefore, how to provide a hydraulic locking device to achieve rapid braking of the shaft core when power is off is a technical problem that technical personnel in this field currently need to solve. Summary of the invention

[0004] The object of the present invention is to provide a hydraulic locking device which can realize rapid braking of a shaft core when power is off.

[0005] To achieve the above object, the present invention provides a hydraulic locking device for braking the shaft core of an electric spindle, the hydraulic locking device comprising:

[0006] A flange assembly can be assembled on the front bearing seat of the electric spindle and is sleeved on the outer periphery of the shaft core, a first gap is provided between the flange assembly and the shaft core, the flange assembly is provided with a receiving cavity, a first through hole connected to the receiving cavity and the first gap, and an oil passage connected to the receiving cavity and located on a side of the receiving cavity away from the first gap;

[0007] The brake assembly is arranged in the accommodating cavity and the first through hole. The hydraulic oil in the oil circuit can drive the brake assembly part to move along the extending direction of the first through hole into the first gap to abut against the outer periphery of the shaft core.

[0008] Preferably, the flange assembly comprises:

[0009] The first flange comprises a first limiting portion and a first connecting portion, wherein the first limiting portion is sleeved on the outer circumference of the shaft core and forms a first gap with the outer circumference of the shaft core, and a first through hole is provided in the circumference of the first limiting portion;

[0010] The second flange includes a second limiting portion and a second connecting portion connected to the first connecting portion, the second limiting portion is provided with a first groove and an oil path connected to the first groove, and the second limiting portion abuts against the outer periphery of the first limiting portion so that the first groove and the outer periphery of the first limiting portion form a accommodating cavity.

[0011] Preferably, the first connecting portion is provided with an oil port, which is connected to the oil circuit and is used for hydraulic oil to flow into and out of the oil circuit.

[0012] Preferably, the oil circuit includes:

[0013] A first flow channel, one end of which is connected to the accommodating cavity, and an axis of the first flow channel is perpendicular to the central axis of the shaft core and has an intersection;

[0014] The second flow channel is connected to an end of the first flow channel away from the accommodating cavity, and the second flow channel is connected to the oil port.

[0015] Preferably, the brake assembly comprises:

[0016] A first brake member is disposed in the accommodating cavity and is interference-fitted with the outer periphery of the first limiting portion, and the first brake member located on the end surface of the first through hole can be deformed into the first through hole;

[0017] The second braking member is disposed in the first through hole and connected to the first braking member, and the second braking member can move along the extending direction of the first through hole.

[0018] Preferably, the second limiting portion is also provided with two second grooves, the two second grooves are opened on the side of the first groove away from the first limiting portion, one end of the first flow channel away from the second flow channel is located between the two second grooves, a first sealing ring is provided in the second groove, and the first sealing ring abuts against the side of the first brake member away from the first limiting portion.

[0019] Preferably, the first through holes are evenly arranged along the circumference of the first limiting portion, and the length direction of the first through holes is parallel to the axial direction of the shaft core.

[0020] Preferably, there are two oil circuits and two oil ports, and the two oil circuits correspond one-to-one to the first through holes that coincide with the two central axes.

[0021] Preferably, the first connecting portion is provided with a first assembly hole and a second assembly hole, the first assembly hole and the second assembly hole are evenly arranged along the circumference of the first connecting portion, and the first assembly hole is located between two adjacent second assembly holes;

[0022] The second connecting part is provided with a third assembly hole corresponding to the first assembly hole, and a fourth assembly hole corresponding to the second assembly hole. The first connecting member can be passed through the corresponding first assembly hole and the third assembly hole to connect the first connecting part and the second connecting part. The second connecting member can be passed through the corresponding second assembly hole and the fourth assembly hole and connect the front bearing seat so that the flange assembly is relatively fixed to the front bearing seat.

[0023] Preferably, the first connecting part is further provided with a third groove, the third groove is opened at one end of the first connecting part facing the second connecting part, the third groove is located at the outer periphery of the oil port, and a second sealing ring is provided in the third groove.

[0024] With respect to the above-mentioned background technology, the hydraulic locking device provided by the present invention is used for braking the shaft core of the electric spindle. The hydraulic locking device includes a flange assembly and a brake assembly. The flange assembly can be assembled on the front bearing seat of the electric spindle and is sleeved on the outer periphery of the shaft core. A first gap is provided between the flange assembly and the shaft core. The flange assembly is provided with a accommodating cavity, a first through hole connected to the accommodating cavity and the first gap, and an oil circuit connected to the accommodating cavity and located on the side of the accommodating cavity away from the first gap; the brake assembly is arranged in the accommodating cavity and the first through hole, and the hydraulic oil in the oil circuit can drive a part of the brake assembly to move along the extension direction of the first through hole into the first gap to abut against the outer periphery of the shaft core.

[0025] Specifically, the brake assembly is arranged in the accommodating cavity and the first through hole. The brake assembly located in the accommodating cavity is squeezed by introducing hydraulic oil into the oil circuit. The hydraulic oil can squeeze the brake assembly toward the direction of the shaft core. The brake assembly located in the accommodating cavity is deformed into the first through hole to squeeze or drive the brake assembly located in the first through hole to move along the extension direction of the first through hole into the first gap and abut against the outer periphery of the shaft core. Through the relative friction between the brake assembly and the outer periphery of the shaft core, the shaft core is quickly braked when the power is off. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0027] Figure 1 A schematic diagram of the structure of a hydraulic braking device provided in an embodiment of the present invention;

[0028] Figure 2 An exploded diagram of a hydraulic braking device provided in an embodiment of the present invention;

[0029] Figure 3 for Figure 1 Left view of

[0030] Figure 4 for Figure 3 Cross-sectional view along EE;

[0031] Figure 5 for Figure 1 Right view of;

[0032] Figure 6 for Figure 5 Cross-sectional view along DD.

[0033] in:

[0034] 100-shaft core;

[0035] 220-first through hole, 230-oil passage, 231-first flow channel, 232-second flow channel, 240-first flange, 241-first limiting portion, 242-first connecting portion, 243-oil port, 244-first assembly hole, 245-second assembly hole, 246-third groove, 250-second flange, 251-second limiting portion, 252-second connecting portion, 253-second groove, 254-third assembly hole, 255-fourth assembly hole;

[0036] 300-brake assembly, 310-first brake member, 320-second brake member;

[0037] 400-First sealing ring. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0040] In the description of the present invention, it should be understood that the terms "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the position or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation of the present invention.

[0041] The object of the present invention is to provide a hydraulic braking device capable of achieving rapid braking of the shaft core 100 when power is off.

[0042] See also Figure 1 and Figure 2 To achieve the above-mentioned purpose, the present invention provides a hydraulic locking device for braking the shaft core 100 of the electric spindle. The hydraulic locking device includes a flange assembly and a brake assembly 300. The flange assembly can be assembled on the front bearing seat of the electric spindle and is sleeved on the outer periphery of the shaft core 100. A first gap is provided between the flange assembly and the shaft core 100. The flange assembly is provided with a accommodating cavity, a first through hole 220 connected to the accommodating cavity and the first gap, and an oil path 230 connected to the accommodating cavity and located on the side of the accommodating cavity away from the first gap.

[0043] The brake assembly 300 is arranged in the accommodating cavity and the first through hole 220, and the hydraulic oil in the oil circuit 230 can drive part of the brake assembly 300 to move along the extension direction of the first through hole 220 to the first gap to abut against the outer periphery of the shaft core 100, wherein part of the brake assembly 300 is located in the accommodating cavity, and part of the brake assembly 300 is located in the first through hole 220, the part of the brake assembly 300 located in the accommodating cavity can contact with the hydraulic oil and can be deformed under the extrusion of the hydraulic oil, and the part of the brake assembly 300 located in the first through hole 220 can move driven by the part of the brake assembly 300 located in the accommodating cavity.

[0044] Specifically, the brake assembly 300 is arranged in the accommodating cavity and the first through hole 220. The brake assembly 300 located in the accommodating cavity is squeezed by introducing hydraulic oil into the oil circuit 230. The hydraulic oil can squeeze the brake assembly 300 toward the direction of the shaft core 100. The brake assembly 300 located in the accommodating cavity is deformed into the first through hole 220 to squeeze or drive the brake assembly 300 located in the first through hole 220 to move along the extension direction of the first through hole 220 into the first gap and abut against the outer periphery of the shaft core 100. Through the relative friction between the brake assembly 300 and the outer periphery of the shaft core 100, the shaft core 100 is quickly braked when the power is off.

[0045] In this embodiment, the flange assembly includes a first flange 240 and a second flange 250. The first flange 240 and the second flange 250 can be made of bronze alloy or hardened steel. The first flange 240 includes a first limiting portion 241 and a first connecting portion 242 connected to each other. The first limiting portion 241 is sleeved on the outer periphery of the shaft core 100 and forms a first gap with the outer periphery of the shaft core 100. When installing the hydraulic locking device, a thin layer of grease is applied to the inner hole of the flange assembly (the inner wall of the first limiting portion 241), and the flange assembly is vertically installed into the shaft core 100 which is absolutely stationary. 00; When assembling the hydraulic braking device, it is necessary to assemble it vertically to prevent air pockets from forming inside the hydraulic braking device; a first through hole 220 is provided in the circumference of the first limiting portion 241; the second flange 250 includes a second limiting portion 251 and a second connecting portion 252 connected to each other, and the second connecting portion 252 is connected to the first connecting portion 242, the second limiting portion 251 is provided with a first groove and an oil path 230 connected to the first groove, and the second limiting portion 251 abuts against the outer periphery of the first limiting portion 241 so that the first groove and the outer periphery of the first limiting portion 241 form a receiving cavity.

[0046] It should be noted that the first limiting portion 241 is arranged on one side of the first connecting portion 242, and the first limiting portion 241 is perpendicular to the first connecting portion 242, the first groove is an annular groove, and the longitudinal section of the annular groove (the cross section parallel to the axis of the annular groove) is square, and is connected to the first connecting portion 242 through the second connecting portion 252, so that one side of the second limiting portion 251 can abut against the first connecting portion 242, and the second limiting portion 251 and the first limiting portion 241 are located on the same side of the first connecting portion 242 to achieve sealing of one side of the first groove, and at the same time, the other end of the second limiting portion 251 is sleeved on the outer periphery of the first limiting portion 241 to achieve sealing of the other side of the first groove, so that the bottom surface of the first groove and the outer periphery of the first limiting portion 241 are surrounded to form a accommodating cavity with an accommodating space.

[0047] See also Figure 5 and Figure 6 , wherein the first connecting portion 242 is provided with a first assembly hole 244 and a second assembly hole 245, the first assembly hole 244 and the second assembly hole 245 are evenly arranged along the circumference of the first connecting portion 242, and the first assembly hole 244 is located between two adjacent second assembly holes 245; the second connecting portion 252 is provided with a third assembly hole 254 corresponding to the first assembly hole 244, and a fourth assembly hole 255 corresponding to the second assembly hole 245, the first connecting member can be passed through the corresponding first assembly hole 244 and the third assembly hole 254 to connect the first connecting portion 242 and the second connecting portion 252, the second connecting member can be passed through the corresponding second assembly hole 245 and the fourth assembly hole 255 and connect the front bearing seat of the electric spindle, so that the flange assembly is relatively fixed to the front bearing seat, and preferably the first connecting portion 242 is fitted to the front bearing seat.

[0048] The first connecting member may adopt a cross recessed countersunk screw to realize the detachable connection between the first connecting portion 242 and the second connecting portion 252. The second connecting member may adopt a hexagon socket head screw to realize the detachable connection between the first connecting portion 242 and the second connecting portion 252 and the front bearing seat. The two hexagon socket head screws may be removed first when disassembly is required, and replaced with longer screws with the same thread specification to screw in, so as to push the flange assembly out of the front bearing seat, thereby improving the disassembly efficiency of the first flange 240 and the second flange 250. In addition, the number of the first assembly holes 244 and the second assembly holes 245 may be adjusted according to actual needs. For example, four first assembly holes 244 and four groups of second assembly holes 245 are provided, each group of second assembly holes 245 includes two second assembly holes 245. After the second assembly holes 245 are evenly arranged along the circumference of the first connecting portion 242, the first assembly holes 244 are respectively arranged between the two second assembly holes 245 in each group of second assembly holes 245, so that the first connecting member and the second connecting member can be staggered.

[0049] In one embodiment, the brake assembly 300 includes a first brake member 310 and a second brake member 320. The first brake member 310 is arranged in the accommodating cavity and has an interference fit with the outer periphery of the first limiting portion 241. The first brake member 310 located at the end face of the first through hole 220 can be deformed into the first through hole 220; the second brake member 320 is arranged in the first through hole 220 and is connected to the first brake member 310. The second brake member 320 can move along the extension direction of the first through hole 220; the first brake member 310 can adopt a circular plastic sheath, which is convenient for interference fit with the outer periphery of the first limiting portion 241 through the plastic sheath, so as to prevent the hydraulic oil from flowing out along the first through hole 220. At the same time, the plastic sheath The sleeve has a certain deformation and recovery ability. It can be deformed in time after being squeezed by the hydraulic oil to drive the movement of the second brake component 320. The second brake component 320 can be made of bronze alloy or hardened steel, and has wear-resistant properties. It can increase the service life of the brake assembly 300. Among them, the distance between the second brake component 320 and the shaft core 100 on the side facing the shaft core 100 is extremely small, so as to ensure that the deformation of the first brake component 310 can quickly drive the second brake component 320 to fit closely to the shaft core 100, so that the shaft core 100 can quickly decelerate to stop rotating. The second brake component 320 can be connected to the first brake component 310 by bonding, snap connection, ultrasonic riveting, etc., which can achieve the above purpose.

[0050] The plastic sheath is partially deformed (the surface in contact with the second brake member 320), the deformed portion moves toward the shaft core 100, the second brake member 320 is squeezed or pushed as a whole and moves toward the shaft core 100 to fill the first gap, the second brake member 320 and the shaft core 100 are in close contact, the first through hole 220 is evenly arranged along the circumference of the first limiting portion 241, and the length direction of the first through hole 220 is parallel to the axial direction of the shaft core 100, so as to increase the contact area between the second brake member 320 and the shaft core 100, and the shaft core 100 is clamped at multiple locations evenly divided around the circumference. Force is used to realize clamping and braking of the shaft core 100, that is, the function of the oil pressure locking device is realized by converting the oil pressure into clamping force through the composite material and flexible metal body adopted by the plastic sheath and the second brake member 320. Preferably, the thickness of the first through hole 220 on its own central axis is greater than the thickness of the first gap, so that the second brake member 320 can achieve contact with the shaft core 100 without completely moving out of the first through hole 220. By transmitting torque, the hole wall of the first through hole 220 can eliminate the movement tendency of the second brake member 320 after friction with the shaft core 100, thereby improving the braking effect.

[0051] See also Figure 3 and Figure 4In one embodiment, the first connecting portion 242 is provided with an oil port 243, the oil port 243 is connected to the oil circuit 230, and the front bearing seat of the electric spindle is also provided with a flow channel connected to the oil port 243, so as to allow the hydraulic oil to flow into and out of the oil circuit 230 along the oil port 243. The oil circuit 230 includes a first flow channel 231 and a second flow channel 232. One end of the first flow channel 231 is connected to the accommodating cavity. The axis of the first flow channel 231 is perpendicular to the central axis of the shaft core 100 and has an intersection, that is, the first flow channel 2 The axial direction of 31 is a radial extension direction of the shaft core 100, which can enable the hydraulic oil flowing along the first flow channel 231 to contact the first brake member 310 to exert pressure in the radial direction of the shaft core 100, thereby improving the squeezing effect of the hydraulic oil on the first brake member 310; the second flow channel 232 is connected to the end of the first flow channel 231 away from the accommodating chamber, and the second flow channel 232 is connected to the oil port 243, and the axes of the second flow channel 232 and the oil port 243 can be aligned to avoid affecting the flow rate of the hydraulic oil.

[0052] Furthermore, the second limiting portion 251 is further provided with two second grooves 253, the two second grooves 253 are opened on the side of the first groove away from the first limiting portion 241, the end of the first flow channel 231 away from the second flow channel 232 is located between the two second grooves 253, a first sealing ring 400 is provided in the second groove 253, and the first sealing ring 400 abuts against the side of the first brake member 310 away from the first limiting portion 241, the two first sealing rings 400 can be made of nitrile rubber (NBR) and are adapted to the first groove. O-rings have a lead angle of 20°, which can prevent The burr scratches the O-ring, and the two first sealing rings 400 play a sealing role when the hydraulic oil flows in and out. The first connecting part 242 is also provided with a third groove 246. The third groove 246 is opened at one end of the first connecting part 242 facing the second connecting part 252. The third groove 246 is located on the outer periphery of the oil port 243, and a second sealing ring is provided in the third groove 246. The provision of the second sealing ring can prevent the hydraulic oil from leaking on the side of the first connecting part 242 and the second connecting part 252 facing each other. Grease can be applied when the first sealing ring 400 and the second sealing ring are placed to facilitate installation.

[0053] In addition, there are two oil circuits 230 and two oil ports 243, and the end faces of the two oil ports 243 are located on the same side of the first connecting portion 242. The axes of the two oil ports 243 are parallel and distributed at 180°. The two oil circuits 230 correspond one-to-one to the two first through holes 220 whose central axes coincide with each other, that is, one oil circuit 230 corresponds to one first through hole 220, and the other oil circuit 230 corresponds to another through hole arranged at 180° to the first through hole 220. The two oil ports 243 are both the inlet and the outlet for the oil, that is, the oil pressure locking device can realize the functions of "one in and one out" and "two in and two out" through the solenoid valve. This function is realized by the recovery of the elastic deformation of the brake assembly 300, which is affected by the strength properties of the material of the brake assembly 300. When the hydraulic braking device stops working, the hydraulic oil does not pass through the hydraulic pump and continuously enter the accommodating chamber from the oil circuit 230. Only the residual hydraulic oil remains in the accommodating chamber. The oil pressure generated by gravity is not enough to overcome the behavior of the brake assembly 300 restoring its elastic deformation. The hydraulic oil is squeezed out of the oil circuit 230 by the force generated by the brake assembly 300 restoring its elastic deformation (only part of the oil remains in the oil circuit 230, which does not affect the use), thereby realizing the oil discharge function.

[0054] In addition, the braking of the shaft core 100 can also be achieved by a locking device having a car brake disc and a caliper, specifically, the brake disc is clamped by an externally controlled caliper, thereby locking the shaft core 100; the braking of the shaft core 100 can also be achieved by setting a locking device of gears and pistons, specifically, a gear is fixed on the shaft core 100, and when braking is required, the piston pushes the gear and the gear on the shaft core 100 to engage, thereby locking the shaft core 100.

[0055] It should be noted that, in this specification, relational terms such as first and second are merely used to distinguish one entity from other entities, but do not necessarily require or imply any actual relationship or order between these entities.

[0056] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0057] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the present invention.

Claims

1. A hydraulic braking device for braking a shaft core (100) of an electric spindle, characterized in that: The oil pressure locking device comprises: A flange assembly capable of being assembled on the front bearing seat of the electric spindle and sleeved on the outer periphery of the shaft core (100), a first gap being provided between the flange assembly and the shaft core (100), the flange assembly being provided with a receiving cavity, a first through hole (220) communicating with the receiving cavity and the first gap, and an oil passage (230) communicating with the receiving cavity and located on a side of the receiving cavity away from the first gap; A brake assembly (300) is disposed in the accommodating cavity and the first through hole (220), and the hydraulic oil in the oil circuit (230) can drive a portion of the brake assembly (300) to move along an extension direction of the first through hole (220) into the first gap to abut against the outer periphery of the shaft core (100).

2. The hydraulic braking device according to claim 1, characterized in that: The flange assembly comprises: A first flange (240) comprises a first limiting portion (241) and a first connecting portion (242); the first limiting portion (241) is sleeved on the outer circumference of the shaft core (100) and forms the first gap with the outer circumference of the shaft core (100); and the first through hole (220) is provided in the circumferential direction of the first limiting portion (241); The second flange (250) comprises a second limiting portion (251) and a second connecting portion (252) connected to the first connecting portion (242), the second limiting portion (251) being provided with a first groove and an oil path (230) connected to the first groove, the second limiting portion (251) being in contact with the outer periphery of the first limiting portion (241), so that the first groove and the outer periphery of the first limiting portion (241) form the accommodating cavity.

3. The hydraulic braking device according to claim 2, characterized in that: The first connecting portion (242) is provided with an oil port (243), and the oil port (243) is connected to the oil circuit (230) and is used for hydraulic oil to flow into and out of the oil circuit (230).

4. The hydraulic braking device according to claim 3, characterized in that: The oil circuit (230) comprises: A first flow channel (231), one end of which is connected to the accommodating cavity, wherein the axis of the first flow channel (231) is perpendicular to the central axis of the shaft core (100) and has an intersection; The second flow channel (232) is connected to an end of the first flow channel (231) away from the accommodating cavity, and the second flow channel (232) is connected to the oil port (243).

5. The hydraulic braking device according to claim 4, characterized in that: The brake assembly (300) comprises: a first braking member (310) disposed in the accommodating cavity and having an interference fit with the outer periphery of the first limiting portion (241); the first braking member (310) located at the end surface of the first through hole (220) can be deformed into the first through hole (220); The second braking member (320) is arranged in the first through hole (220) and connected to the first braking member (310), and the second braking member (320) is capable of moving along an extension direction of the first through hole (220).

6. The hydraulic braking device according to claim 5, characterized in that: The second limiting portion (251) is further provided with two second grooves (253), the two second grooves (253) being opened on the side of the first groove facing away from the first limiting portion (241), one end of the first flow channel (231) facing away from the second flow channel (232) is located between the two second grooves (253), a first sealing ring (400) is provided in the second groove (253), and the first sealing ring (400) abuts against the side of the first brake member (310) facing away from the first limiting portion (241).

7. The hydraulic braking device according to claim 4, characterized in that: The first through holes (220) are evenly arranged along the circumference of the first limiting portion (241), and the length direction of the first through holes (220) is parallel to the axial direction of the shaft core (100).

8. The hydraulic braking device according to claim 4, characterized in that: There are two of each of the oil circuits (230) and the oil ports (243), and the two oil circuits (230) correspond one to one with two first through holes (220) whose central axes coincide with each other.

9. The hydraulic braking device according to claim 4, characterized in that: The first connecting portion (242) is provided with a first assembly hole (244) and a second assembly hole (245), the first assembly hole (244) and the second assembly hole (245) are evenly arranged along the circumference of the first connecting portion (242), and the first assembly hole (244) is located between two adjacent second assembly holes (245); The second connecting portion (252) is provided with a third assembly hole (254) corresponding to the first assembly hole (244), and a fourth assembly hole (255) corresponding to the second assembly hole (245); a first connecting member can be inserted into the corresponding first assembly hole (244) and the third assembly hole (254) to connect the first connecting portion (242) and the second connecting portion (252); a second connecting member can be inserted into the corresponding second assembly hole (245) and the fourth assembly hole (255) and connected to the front bearing seat, so that the flange assembly is relatively fixed to the front bearing seat.

10. The hydraulic braking device according to claim 4, characterized in that: The first connecting portion (242) is further provided with a third groove (246). The third groove (246) is opened at one end of the first connecting portion (242) facing the second connecting portion (252). The third groove (246) is located at the outer periphery of the oil port (243), and a second sealing ring is provided in the third groove (246).

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