A constant current controlled power-off brake

Abstract

The embodiment of the present application provides a constant current controlled power-off brake. The brake includes: a moving iron core assembly and a stationary iron core assembly, wherein the friction ring in the moving iron core assembly can contact and rub with the iron core shell in the stationary iron core assembly to generate a friction torque; the power-off brake also includes: a constant current drive assembly, fixedly mounted on the moving iron core assembly, for constant current control of the current passing through the armature in the stationary iron core assembly, so that the friction ring is separated and unlocked from the iron core shell; the constant current drive assembly includes: a circuit board mounting seat, fixedly mounted on the iron core shell of the stationary iron core assembly; a circuit board, fixedly mounted on the circuit board mounting seat, and insulated from the circuit board mounting seat, and a constant current drive circuit is printed on the circuit board, wherein the constant current drive circuit is used to detect the actual current of the armature, and adjust the PWM duty cycle according to the actual current and the preset current, so that the current of the armature is maintained constant.

Description

Technical Field

[0001] The present application relates to the technical field of brakes, and in particular to a power-loss brake with constant current control. Background Art

[0002] Brakes have been widely developed and applied in various industries such as metallurgy, mining, automobiles, and elevators. Permanent magnet brakes mainly include static iron core components and moving iron core components. The static iron core includes an outer shell, an inner shell, an armature, a permanent magnet, etc., and the moving iron core mainly includes a friction ring, an annular spring, etc.

[0003] When general permanent magnet brakes and traditional spring-type electromagnetic brakes operate at rated working voltage, at low temperatures, the resistance of the winding becomes smaller and the current becomes larger, causing the armature winding to burn out; at high temperatures, the winding resistance becomes larger and the current becomes smaller, causing the brake to fail to unlock; therefore, it is difficult to adapt to the requirements of high and low temperature operating temperatures (for example, a temperature range of -55 degrees Celsius to 85 degrees Celsius).

[0004] Therefore, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Summary of the invention

[0005] In view of this, an embodiment of the present application provides a constant current controlled power-off brake to solve or alleviate the technical problems existing in the above-mentioned technology.

[0006] An embodiment of the present application provides a constant current controlled power-off brake, comprising: a moving iron core assembly and a stationary iron core assembly, wherein a friction ring in the moving iron core assembly can contact and rub with an iron core shell in the stationary iron core assembly to generate a friction torque; the power-off brake also comprises: a constant current drive assembly, fixedly mounted on the moving iron core assembly, for performing constant current control on the current passing through the armature in the stationary iron core assembly, so as to separate and unlock the friction ring from the iron core shell; the constant current drive assembly comprises: a circuit board mounting seat, fixedly mounted on the iron core shell of the stationary iron core assembly; a circuit board, fixedly mounted on the circuit board mounting seat and insulated from the circuit board mounting seat, a constant current drive circuit printed on the circuit board, wherein the constant current drive circuit is used to detect the actual current of the armature, and adjust the PWM duty cycle according to the actual current and the preset current, so as to maintain the current of the armature constant.

[0007] In some optional embodiments of the present application, the circuit board mounting seat includes: a side wall, which is an annular structure and the inner surface cooperates with the core shell; a mounting base plate, connected to one end of the annular structure, for mounting the circuit board; wherein the static core assembly is inserted into the side wall from the other end of the annular structure.

[0008] In some optional embodiments of the present application, a wire outlet hole is radially provided on the side wall and penetrates the side wall, and the wire outlet hole is used to lead out the lead wires of the armature so that the lead wires are electrically connected to the circuit board.

[0009] In some optional embodiments of the present application, a groove is provided on the outer surface of the side wall along the axial direction, one end of the groove is connected to the wire outlet hole, and the other end passes through the side wall for laying the lead wire.

[0010] In some optional embodiments of the present application, the groove is filled with vulcanized silicone rubber to fix the lead wire in the groove.

[0011] In some optional embodiments of the present application, the constant current drive assembly further includes: an insulating gasket, located between the circuit board and the circuit board mounting seat, for insulating the circuit board from the circuit board mounting seat.

[0012] In some optional embodiments of the present application, a first through hole is provided on the circuit board, and correspondingly, a second through hole is provided on the insulating gasket ring, and screws are passed through the first through hole and the second through hole in sequence to be screwed to the mounting base plate to fix the circuit board to the mounting base plate.

[0013] In some optional embodiments of the present application, the constant current drive circuit detects the actual current of the armature in real time through a sampling resistor, and adjusts the PWM duty cycle according to the difference between the actual current and the preset current to maintain the current of the armature constant.

[0014] In some optional embodiments of the present application, the circuit board mounting seat is made of non-magnetic stainless steel, and / or the friction ring is made of soft magnetic alloy with surface plating.

[0015] In some optional embodiments of the present application, the core outer shell and the core inner shell in the static core assembly are made of soft magnetic alloy, and the magnetic steel in the static core assembly is made of samarium cobalt permanent magnet.

[0016] Compared with the closest prior art, the technical solution of the embodiment of the present application has the following beneficial effects:

[0017] The actual current of the armature in the static iron core assembly is detected by the constant current drive assembly installed on the moving iron core assembly, and the duty cycle of the PWM is adjusted according to the actual current and the preset current. The current of the armature is maintained constant to achieve constant current control of the armature current, thereby avoiding the armature winding burning out at low temperatures due to the power-off brake, and ensuring that the power-off brake is effectively unlocked at high temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application 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 some embodiments recorded in the embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0019] Figure 1 A schematic diagram of the structure of a power-loss brake with constant current control provided according to some embodiments of the present application;

[0020] Figure 2 A schematic diagram of the structure of a static iron core assembly provided according to some embodiments of the present application;

[0021] Figure 3 A schematic diagram of the structure of a moving iron core assembly provided according to some embodiments of the present application;

[0022] Figure 4 A schematic diagram of the structure of a constant current drive component provided according to some embodiments of the present application;

[0023] Figure 5 A schematic diagram of the structure of an annular spring provided according to some embodiments of the present application;

[0024] Figure 6 A schematic front view of a shaft sleeve provided according to some embodiments of the present application;

[0025] Figure 7 A schematic side view of a sleeve provided according to some embodiments of the present application;

[0026] Figure 8 It is a structural schematic diagram of a power-off brake in an engaged state according to some embodiments of the present application;

[0027] Fig. 9 A magnetic field distribution diagram of a power-off brake in an engaged state according to some embodiments of the present application;

[0028] Fig.10 A magnetic field distribution diagram at the moment of unlocking a power-off brake provided according to some embodiments of the present application;

[0029] Fig.11 A magnetic field distribution diagram after the power-off brake is unlocked according to some embodiments of the present application;

[0030] Fig.12 A schematic structural diagram of a power-off brake unlocking state provided according to some embodiments of the present application;

[0031] Fig.13 A circuit schematic diagram of a constant current drive circuit provided according to some embodiments of the present application.

[0032] Description of reference numerals:

[0033] 1-static iron core assembly; 2-moving iron core assembly; 3-constant current drive assembly; 4-mounting base; 5-brass washer; 6-core shell; 7-armature; 8-armature lead wire; 9-magnet; 10-core inner shell; 11-sleeve; 12-annular spring; 13-rivet; 14-friction ring; 15-circuit board mounting seat; 16-insulating gasket; 17-circuit board; 18-screw; 19-circuit board lead wire. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the embodiments of the present application should fall within the scope of protection of the embodiments of the present application.

[0035] In the description of the present application, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention. The terms "connected", "connected", and "set" used in the present invention should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection; it can be a direct connection or an indirect connection through an intermediate component; it can be a wired electrical connection, a radio connection, or a wireless communication signal connection. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0036] First, in the embodiment of the present application, taking the permanent magnet brake as an example, the static iron core assembly 1 and the moving iron core assembly 2 in the power-off brake and their structures are described. The static iron core assembly 1 generally includes: a mounting base 4, a brass washer 5, an iron core shell 6, an armature 7, an armature lead wire 8, a magnetic steel 9, and an iron core inner shell 10. It is an assembled structure, and its components are connected together by pins and glue. The moving iron core assembly 2 generally includes: a sleeve 11, an annular spring 12, a rivet, a friction ring 14, etc., which are riveted bidirectionally by rivets. Among them, the armature 7 is located between the core inner shell 10 and the core outer shell 6, and is made of enameled wire on the insulating skeleton, and is formed and fixed by brushing glue; the brass washer 5 is located between the mounting base 4 and the core outer shell 6, and is used to isolate the core outer shell 6 and the mounting base 4 from the magnetic field; the magnetic steel 9 is located in the gap between the lower side of the core outer shell 6 and the upper side of the core inner shell; the annular spring 12 is made of spring steel, one side is in contact with the friction ring 14, and the other side is in contact with the sleeve 11, and the sleeve 11, the annular spring 12, and the friction ring 14 are riveted together by rivets (the sleeve 11, the annular spring 12, and the friction ring 14 are all processed with matching holes for riveting). It can be understood that the above description is only exemplary, and the embodiments of the present application are not limited to this.

[0037] Secondly, in the embodiment of the present application, the PWM (Pulse Width Modulation) duty cycle is the ratio of the time of outputting a high level in one cycle to the entire cycle. It can be understood that the above description is only exemplary and the embodiment of the present application does not limit this.

[0038] like Figure 1-Figure 7 As shown, the constant current controlled power-off brake comprises: a moving iron core assembly 2 and a stationary iron core assembly 1, wherein the friction ring 14 in the moving iron core assembly 2 can be connected to the iron core housing 6 in the stationary iron core assembly 1 to generate a friction torque; the power-off brake also comprises: a constant current drive assembly 3, fixedly mounted on the moving iron core assembly 2, for constant current control of the current passing through the armature 7 in the stationary iron core assembly 1, so that the friction ring 14 is separated and unlocked from the iron core housing 6; the constant current drive assembly 3 comprises: a circuit board mounting seat 15, fixedly mounted on the iron core housing 6 of the stationary iron core assembly 1; a circuit board 17, fixedly mounted on the circuit board mounting seat 15, and insulated from the circuit board mounting seat 15, and a constant current drive circuit is printed on the circuit board, wherein the constant current drive circuit is used to detect the actual current of the armature 7, and adjust the duty cycle of the PWM according to the actual current and the preset current, so that the current of the armature 7 is maintained constant. It can be understood that the above description is only exemplary, and the embodiment of the present application is not limited to this.

[0039] In the embodiment of the present application, the actual current of the armature 7 in the static iron core assembly 1 is detected by the constant current drive assembly 3 installed on the moving iron core assembly 2, and the duty cycle of the PWM is adjusted according to the actual current and the preset current, so that the current of the armature 7 is maintained constant, and the constant current control of the current of the armature 7 is achieved, so as to avoid the armature 7 from being burned out by the power-off brake at low temperatures, and ensure that the power-off brake is effectively unlocked at high temperatures. It can be understood that the above description is only exemplary, and the embodiment of the present application does not limit this.

[0040] In the embodiment of the present application, the power-off brake mainly generates a braking torque by friction between the friction ring 14 and the core housing 6. When the power-off brake is in a power-off state, the magnetic force of the magnetic steel on the friction ring 14 is greater than the elastic force of the annular spring 12, and the brake is engaged. At this time, the air gap X0 between the friction ring 14 and the core housing 6 of the static core assembly 1 is zero (such as Figure 8 As shown), the magnetic field lines between the friction ring 14 and the static iron core are the most dense (as shown Fig. 9 As shown in FIG. 1 , at this time, the positive pressure on the cross section of the static core assembly 1 is the largest, which is the difference between the magnetic force of the magnetic steel 9 and the elastic force of the annular spring 12, thereby generating a static friction torque on the contact surface between the core housing 6 and the friction ring 14 to achieve braking. It can be understood that the above description is only exemplary and is not limited to this embodiment of the present application.

[0041] In the embodiment of the present application, when the power-off brake is energized, the armature 7 generates a magnetic field, and the combined force of the magnetic force of the magnetic field of the armature 7 on the friction ring 14 and the magnetic force of the magnetic steel 9 on the friction ring 14 is less than the elastic force of the annular spring 12 at this time. At this time, the magnetic field at the air gap between the friction ring 14 and the core shell 6 of the static core assembly 1 is greatly weakened, and the magnetic lines of force between the friction ring 14 and the static core are very sparse (such as Fig.10 , Fig.11 As shown), the magnetic force on the friction ring 14 is the smallest, and the elastic force of the annular spring 12 is greater than the combined magnetic force of the armature 7 and the magnetic steel 9 on the friction ring 14; the annular spring 12 pulls the friction ring 14 back, and the air gap between the friction ring 14 and the core housing 6 of the static core assembly 1 returns to the initial state X1 (X1>0) (as shown Fig.12 It can be understood that the above description is only exemplary and the embodiments of the present application do not limit this.

[0042] In the embodiment of the present application, the circuit board 17 is painted with three-proof paint, and the circuit board lead wire 19 of the circuit board 17 is led downward and connected to an external power supply so that the power-off brake is powered by the external power supply. The sampling resistor uses a resistor with a very small temperature drift (used to indicate the magnitude of the change in resistance with temperature), such as a metal film resistor (low temperature coefficient of 50 (PPM / ℃)). In a specific example, the sampling resistor is a resistor model CSSH2728FT50L0 produced by Stackpole Electronics. Inc. (SEI), with a temperature drift of 15PPM and a resistance of 0.15 ohms. It can be understood that the above description is only exemplary and the embodiment of the present application does not limit this.

[0043] In some optional embodiments, the circuit board mounting seat 15 includes: a side wall, the side wall is an annular structure, and the inner surface matches the core housing 6; a mounting base plate connected to one end of the annular structure, and used to mount the circuit board 17; wherein the static core assembly 1 is inserted into the side wall from the other end of the annular structure. It can be understood that the above description is only exemplary, and the embodiments of the present application are not limited thereto.

[0044] In the embodiment of the present application, the circuit board mounting seat 15 can be formed by one-piece molding, or it can be formed by splicing a split structure, for example, the side wall and the mounting base are processed separately and then welded together. The mounting base is adapted to the end of the annular structure, for example, the mounting base is a circular structure, and the diameter is the same as the inner diameter or outer diameter of the annular structure of the side wall. When the diameter of the mounting base is the same as the inner diameter of the annular structure, the side of the mounting base contacts the inner side wall of the annular structure (for example, welding); when the diameter of the mounting base is the same as the outer diameter of the annular structure, the end face of the annular structure contacts the bottom surface of the mounting base (for example, welding). It can be understood that the above description is only exemplary, and the embodiment of the present application does not limit this.

[0045] In an embodiment of the present application, an annular cavity is formed between the annular structure of the side wall and the mounting base, and the static iron core assembly 1 is inserted into the annular cavity from one end of the annular structure of the side wall, and the iron core housing 6 is fixedly connected to the side wall, for example, by pins. Thereby, the constant current drive assembly 3 is connected to the iron core housing 6 through the circuit board mounting seat 15, which is convenient for installation and maintenance, as well as circuit routing. Moreover, the static iron core assembly 1 is inserted into the annular cavity of the circuit board mounting seat 15, which can effectively protect the static iron core assembly 1 and the moving iron core assembly 2 connected to the static iron core assembly 1 (for example, the moving iron core assembly 2 is connected to one end of the static iron core assembly 1, and is located between the mounting base and the static iron core assembly 1). It can be understood that the above description is only exemplary, and the embodiment of the present application does not limit this.

[0046] In a specific example, a wire outlet hole is radially provided on the side wall and penetrates the side wall, and the wire outlet hole is used to lead out the lead wire of the armature 7 so that the lead wire is electrically connected to the circuit board 17. It can be understood that the above description is only exemplary and the embodiment of the present application does not limit this.

[0047] In the embodiment of the present application, the lead wires of the armature 7 are electrically connected to the circuit board 17 by setting the lead wire holes radially on the side wall. In this way, based on the structural form of the armature lead wires 8 of the original permanent magnet brake, the radial space of the side wall is fully utilized to connect the armature lead wires 8 to the circuit board 17, which is convenient for circuit wiring. At the same time, it is beneficial to reduce the processing design cost. It can be understood that the above description is only exemplary and the embodiment of the present application does not limit this.

[0048] In another specific example, a groove is provided on the outer surface of the side wall along the axial direction, one end of the groove is connected to the outlet hole, and the other end passes through the side wall for laying the lead wire. It can be understood that the above description is only exemplary and the embodiments of the present application do not limit this.

[0049] In the embodiment of the present application, the lead wires of the armature 7 are led out from the lead hole of the side wall, laid in the groove, and connected to the circuit board 17, thereby not only making the outer surface of the side wall smoother, but also making the circuit wiring neat and beautiful. It can be understood that the above description is only exemplary and the embodiment of the present application does not limit this.

[0050] In one application scenario, the groove is filled with vulcanized silicone rubber to fix the lead wire in the groove. For example, the model of the vulcanized silicone rubber is GD414 glue, whereby the lead wire of the armature 7 is fixed in the groove by GD414 glue to prevent the lead wire from falling off. It is understandable that the above description is only exemplary and the embodiments of the present application are not limited to this.

[0051] In some optional embodiments, the constant current drive component 3 further includes: an insulating gasket 16, located between the circuit board 17 and the circuit board mounting seat 15, for insulating the circuit board 17 from the circuit board mounting seat 15. It can be understood that the above description is only exemplary and the embodiments of the present application are not limited thereto.

[0052] In the embodiment of the present application, the circuit board 17 is printed with various circuits, and the circuit board mounting seat 15 is made of metal. In order to avoid a short circuit between the circuit and the circuit board mounting seat 15, when the circuit board 17 is mounted on the circuit board mounting seat 15, it is necessary to ensure that the circuit board 17 and the circuit board mounting seat 15 are insulated. It can be understood that the above description is only exemplary and the embodiment of the present application does not limit this.

[0053] In the embodiment of the present application, an insulating gasket 16 made of polyimide is provided between the circuit board 17 and the circuit board mounting seat 15 to achieve insulation between the circuit board 17 and the circuit board mounting seat 15, thereby ensuring effective stability of each circuit on the circuit board 17. It is understood that the above description is only exemplary and is not limited to this embodiment of the present application.

[0054] In a specific example, the circuit board 17 is provided with a first through hole, and correspondingly, the insulating gasket 16 is provided with a second through hole, and a screw 18 is passed through the first through hole and the second through hole in sequence to be screwed to the mounting base plate, so as to fix the circuit board 17 to the mounting base plate. It can be understood that the above description is only exemplary, and the embodiments of the present application are not limited to this.

[0055] In the embodiment of the present application, the sizes of the first through hole and the second through hole are matched, so that the circuit board 17 can be fixed to the mounting base plate by screws 18. It can be understood that the above description is only exemplary and the embodiment of the present application does not limit this.

[0056] In the embodiment of the present application, the insulating gasket 16 is columnar (such as cylindrical, prism or truncated cone), and a second through hole is provided along the axial direction of the column, so that the second through hole passes through the insulating gasket 16 to facilitate passing the screw 18. It can be understood that the above description is only exemplary and the embodiment of the present application does not limit this.

[0057] In the embodiment of the present application, a threaded hole is provided on the mounting base plate, and the threaded hole is adapted to the screw 18 for fixing the circuit board 17. When processing the threaded hole on the mounting base plate, a positioning center hole is set on the mounting base plate, and the threaded hole is processed around the positioning center hole to achieve the matching with the first through hole on the circuit board 17. The number of threaded holes on the mounting base plate is the same as the number of the first through holes. When there are multiple threaded holes, the multiple threaded holes are evenly distributed along the positioning center hole, thereby effectively fixing the circuit board 17 on the mounting base plate to prevent the circuit board 17 from sliding, etc. It can be understood that the above description is only exemplary, and the embodiment of the present application does not limit this.

[0058] In some optional embodiments, the constant current drive circuit detects the actual current of the armature 7 in real time through a sampling resistor, and adjusts the duty cycle of PWM according to the difference between the actual current and the preset current, so as to maintain a constant current of the armature 7. It can be understood that the above description is only exemplary and the embodiments of the present application are not limited thereto.

[0059] In the embodiment of the present application, the actual current through the winding of the armature 7 is detected in real time by a sampling resistor, and the actual current is compared with the threshold of the preset current (for example, the actual current is compared with the preset current by a comparator). When the actual current detected is greater than the preset current, the duty cycle of the PWM is adjusted to decrease so that the actual current of the armature 7 is maintained at a constant current; when the actual current detected is less than the preset current, the duty cycle of the PWM is adjusted to increase so that the actual current of the armature 7 is maintained at a constant current. In this way, the armature 7 winding is effectively prevented from being burned out by the power-off brake at low temperatures, and at the same time, the power-off brake is effectively unlocked at high temperatures. It can be understood that the above description is only exemplary and the embodiment of the present application does not limit this.

[0060] In the embodiments of the present application, Fig.13 As shown, D1 represents a freewheeling diode (when the switch device is closed, the winding continues to flow through the freewheeling diode), C1 represents an energy storage capacitor, Rs represents a sampling resistor (converts the current signal in the circuit into a voltage signal), V+ represents the power supply, Vin represents the power input line, Isense represents current detection, GND represents the ground reference level, and Drv represents the switch tube drive output. The winding current of the armature 7 is collected through the sampling resistor Rs, and the duty cycle of the PWM is adjusted according to the difference between the actual current of the winding and the preset current, so as to realize constant current control of the actual current of the winding of the armature 7. It can be understood that the above description is only exemplary and the embodiments of the present application are not limited to this.

[0061] In some optional embodiments, the circuit board mounting base 15 is made of non-magnetic stainless steel, and / or the friction ring 14 is made of soft magnetic alloy, and the surface is chrome-plated. The core shell 6 and the core inner shell 10 in the static core assembly 1 are both made of soft magnetic alloy, and the magnetic steel in the static core assembly 1 is a samarium cobalt permanent magnet. Thereby, under high and low temperature working conditions, the operation of the power-off brake is more stable and reliable. It can be understood that the above description is only exemplary, and the embodiments of the present application do not limit this.

[0062] In the embodiment of the present application, the magnetic steel has a magnetic effect on the friction ring 14, providing positive pressure for the brake. The samarium cobalt permanent magnet (for example, Sm2Co 17) As a raw material for magnetic steel, it has a high torque density and good magnetic stability under high and low temperature conditions. Therefore, the electromagnetic volume of the brake can be effectively reduced, the torque density of the brake can be improved, and the miniaturized design and production of the brake can be realized. The circuit board mounting seat 15, the shaft sleeve 11 in the moving iron core assembly 2 and other components are processed using non-magnetic stainless steel, so that the processed components have a good thermal expansion coefficient and can work more stably and reliably in high and low temperature environments. Thereby, the problem of floating working current and large deformation of components of the power-off brake, which causes the brake to get stuck or cannot be unlocked reliably, is effectively avoided, thereby improving the reliability of the power-off brake. It will be understood that the above description is only exemplary and is not limited to the embodiments of the present application.

[0063] In the embodiment of the present application, the sleeve 11 is a cylindrical structure, wherein a connecting flange is provided at one end of the cylindrical structure in the radial direction, and a plurality of first through holes are evenly arranged on the flange surface of the connecting flange along the axis of the sleeve 11, wherein each first through hole is adapted to the second through hole on the friction ring 14. The annular spring 12 is located between the connecting flange and the friction ring 14, and a third through hole is provided thereon, and the third through hole is adapted to the first through hole and the second through hole. The rivet 13 (or bolt fastener, etc.) passes through the second through hole, the third through hole, and the first through hole, and the annular spring 12 is pressed against the flange surface through the friction ring 14. It can be understood that the above description is only exemplary, and the embodiment of the present application does not limit this.

[0064] In the embodiment of the present application, the friction ring 14 is an annular structure, and the central circular ring of the friction ring 14 is sleeved on one end of the shaft sleeve 11 provided with a connecting flange. When the friction ring 14 presses the annular spring 12 onto the connecting flange, the outer end surface of the friction ring 14 is flush with the end surface of the shaft sleeve 14. The outer end surface of the friction ring 14 is the side opposite to the contact surface between the friction ring 14 and the annular spring 12. It can be understood that the above description is only exemplary and is not limited to this in the embodiment of the present application.

[0065] In the embodiment of the present application, the friction ring 14, the core shell 6, and the core inner shell 10 are all made of soft magnetic alloy (for example, 1J50). Thereby, the friction ring 14, the core shell 6, and the core inner shell 10 have better magnetic conductivity and are not easy to rust. In addition, the friction ring 14, the core shell 6, the core inner shell 10 and other components can also be made of No. 10 steel to save costs. It can be understood that the above description is only exemplary and the embodiment of the present application does not limit this.

[0066] In the embodiment of the present application, the constant current control component controls the current of the armature 7, so that the current passing through the armature 7 remains constant; at the same time, each component is made of a material with a low thermal expansion coefficient, which effectively reduces the influence of the power-off brake on the external temperature change during operation, and ensures the safety and reliability of the power-off brake during operation. It can be understood that the above description is only exemplary, and the embodiment of the present application does not limit this.

[0067] It should be noted that each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. Some or all of the modules can be selected according to actual needs to achieve the purpose of the embodiment scheme. Ordinary technicians in this field can understand and implement it without paying creative work.

[0068] The above implementation methods are only used to illustrate the embodiments of the present application, rather than to limit the embodiments of the present application. Ordinary technicians in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the embodiments of the present application. Therefore, all equivalent technical solutions also belong to the scope of the embodiments of the present application. The professional protection scope of the embodiments of the present application should be defined by the claims.

Claims

1. A constant current controlled power-off brake, comprising: A moving iron core assembly and a stationary iron core assembly, wherein the friction ring in the moving iron core assembly can contact and rub with the iron core shell in the stationary iron core assembly to generate a friction torque; characterized in that: The power-off brake further includes: a constant current drive component, fixedly mounted on the moving iron core component, for performing constant current control on the current passing through the armature in the stationary iron core component, so as to separate and unlock the friction ring from the iron core housing; the constant current drive component includes: A circuit board mounting seat, fixedly mounted on the iron core shell of the static iron core assembly; A circuit board is fixedly mounted on the circuit board mounting base and insulated from the circuit board mounting base, and a constant current drive circuit is printed on the circuit board, wherein the constant current drive circuit is used to detect the actual current of the armature and adjust the PWM duty cycle according to the actual current and the preset current to keep the current of the armature constant.

2. The brake according to claim 1, characterized in that The circuit board mounting seat comprises: A side wall, wherein the side wall is an annular structure, and the inner surface thereof matches the core shell; A mounting base plate connected to one end of the ring structure and used for mounting the circuit board; Wherein, the static iron core component is sleeved into the side wall from the other end of the annular structure.

3. The brake according to claim 2, characterized in that The side wall is provided with a wire outlet hole which penetrates the side wall in a radial direction, and the wire outlet hole is used for leading out the lead wire of the armature so that the lead wire is electrically connected to the circuit board.

4. The brake according to claim 3, characterized in that A groove is axially arranged on the outer surface of the side wall, one end of the groove is communicated with the lead-out hole, and the other end passes through the side wall for laying the lead-out wire.

5. The brake according to claim 4, characterized in that The groove is filled with vulcanized silicone rubber to fix the lead wire in the groove.

6. The brake according to claim 2, characterized in that The constant current driving component further includes: an insulating gasket, which is located between the circuit board and the circuit board mounting seat and is used to insulate the circuit board from the circuit board mounting seat.

7. The brake according to claim 6, characterized in that The circuit board is provided with a first through hole, and correspondingly, the insulating gasket is provided with a second through hole, and screws are passed through the first through hole and the second through hole in sequence to be screwed to the mounting base plate to fix the circuit board on the mounting base plate.

8. The brake according to claim 1, characterized in that The constant current drive circuit detects the actual current of the armature in real time through a sampling resistor, and adjusts the duty cycle of PWM according to the difference between the actual current and the preset current, so as to maintain the current of the armature constant.

9. The brake according to claim 1, characterized in that The circuit board mounting seat is made of non-magnetic stainless steel, and / or the friction ring is made of soft magnetic alloy with a surface coating.

10. The brake according to any one of claims 1 to 9, characterized in that: The iron core outer shell and the iron core inner shell in the static iron core assembly are both made of soft magnetic alloy, and the magnetic steel in the static iron core assembly is made of samarium cobalt permanent magnet.

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