Linear motor braking structure and braking system based on same

Abstract

The invention discloses a linear motor braking structure and a braking system based on the structure. The linear motor braking structure comprises a stator core, a braking winding and a short-circuit copper bar. A wire clamping groove matched with the brake winding is arranged along the length direction of the stator core, and the short-circuit copper bar is connected with the brake winding; the whole brake winding is a 4Y winding, and the head and the tail of each Y winding in the 4Y winding are short-circuited to form a Y shape; according to the scheme, the application range is wide, the braking distance is short, and the braking problem of the ultra-high-speed linear motor is innovatively solved. At present, the maximum speed of a linear motor which is put into operation is about 600km / h, most linear motors are long lines of dozens of kilometers, enough braking lines exist, a regenerative braking mode is adopted mostly, and the braking deceleration is small. By means of the structure, stable deceleration and parking of hundreds of kilograms of objects running 1500 km / h within hundreds of meters can be achieved, the braking system can flexibly match and set braking intervals according to the braking initial speed requirement, and global braking is achieved.

Description

Technical Field

[0001] The invention relates to the field of linear motor braking, and in particular to a linear motor braking structure and a braking system based on the structure. Background Art

[0002] At present, the three main braking methods for linear motors are regenerative braking, series resistor braking, and eddy current braking. Regenerative braking uses vector control to make the linear motor work in a power generation state, and the electromagnetic thrust is the braking force. The series resistor braking method uses a large resistor in series in the stator winding of the linear motor, and the energy is consumed by the resistor. The eddy current braking method uses a brake plate installed on the end face of the stator core, and brake plates with different resistivity are set according to the motor running speed to achieve the braking function. Among the above three braking methods, regenerative braking increases the difficulty and complexity of system control, and greatly increases the equipment investment cost; the series resistor braking method connects the brake resistor in series into each phase brake winding through a cable, which requires a large space to arrange the resistor cabinet, and the scope of application is limited. It is not an ideal braking method; the eddy current braking method is only suitable for low-speed motor braking, and the braking force is small. In order to obtain a better braking effect, it is necessary to set a variety of material brakes according to different speeds. Summary of the invention

[0003] The purpose of the present invention is to provide a linear motor braking structure and a braking system based on the structure to address the above-mentioned deficiencies, thereby solving the deficiencies in the prior art feedback braking, series resistance braking, and eddy current braking.

[0004] The present invention is achieved through the following scheme:

[0005] A linear motor braking structure includes at least but not limited to a stator core, a brake winding and a short-circuited copper bar; a wire clamping groove cooperating with the brake winding is arranged along the length direction of the stator core, and the short-circuited copper bar is connected to the brake winding; the brake winding is a 4Y winding as a whole, and the head and tail of each Y winding in the 4Y winding are short-circuited into a Y shape.

[0006] Based on the above-mentioned linear motor braking structure, the stator core includes stator punching sheets, stator pressure rings and insulating screws; the stator punching sheets are stacked into multiple sheets in the vertical direction to form a stator core, and the stator pressure rings are respectively arranged on the upper and lower end surfaces of the stator core, and the wire clamping grooves of multiple stator punching sheets are stacked in the same direction to form long wire clamping grooves. The stator punching sheets and stator pressure rings are both provided with multiple through holes cooperating with the insulating screws along their length direction, and the insulating screws are arranged to pass through them.

[0007] Based on the above-mentioned linear motor braking structure, the insulating screw includes a stud, a nut, a flat washer, an insulating washer and an insulating sleeve; the insulating sleeve passes through the stator punching sheet and the through hole on the stator pressure ring, the stud screw is sleeved in the insulating sleeve, the nut, flat washer and insulating washer are respectively arranged on both sides of the stud screw and contact with the stator pressure ring to lock the stator core.

[0008] Based on the above-mentioned linear motor braking structure, the braking winding is a single-layer, full-pitch, wave winding. The lead wires of the braking winding are bent toward the back of the core and staggered in vertical layers. The short-circuited copper bar and the lead wires of the winding are fixed by brazing and passed the PT flaw detection after welding.

[0009] Based on the above-mentioned linear motor brake structure, A1 / B1 / C1, A2 / B2 / C2, A3 / B3 / C3, and A4 / B4 / C4 of the brake winding are staggered in 4 layers in the height direction; the material of the short-circuit copper bar is consistent with that of the brake winding, and a total of 8 short-circuit copper bars are arranged in each brake structure; 1# copper bar is connected to A1 / B1 / C1, 2# copper bar is connected to A2 / B2 / C2, 3# copper bar is connected to A3 / B3 / C3, and 4# copper bar is connected Connect A4 / B4 / C4, 5# copper busbar connects -C1 / -A1 / -B1, 6# copper busbar connects -C2 / -A2 / -B2, 7# copper busbar connects -C3 / -A3 / -B3, 8# copper busbar connects -C4 / -A4 / -B4; the short-circuit copper busbar is half-wrapped with a specified number of layers of mica tape as required by the low vacuum insulation specification, the outer half is wrapped with 1 layer of low-resistance anti-corona tape, and the last half is wrapped with 1 layer of glass fiber tape; the overlap length between the copper busbar insulation and the winding insulation should be greater than 30mm.

[0010] The present solution also discloses a linear motor braking system, comprising a plurality of braking units spaced apart along the length direction, each braking unit comprising a symmetrically arranged braking structure, the end faces of the symmetrically arranged braking structures being aligned with each other, and the distance between the two braking structures arranged on the opposite sides being adapted to the structure of the mover.

[0011] Based on the above linear motor braking system, the winding inductance Li remains unchanged during the braking process. In order to ensure that the electrical time constant e has the least effect on the braking current, different winding resistances need to be set according to different speed ranges to ensure that the average braking deceleration is maximized and the braking effect is optimal. The details are as follows:

[0012] When the braking speed is in the range of V1 to V2, a brake winding with a resistivity of ρ1 and a cross section of S1 is set to ensure that the bilateral brake unit provides a braking deceleration of g1;

[0013] When the braking speed is in the range of V2 to V3, a brake winding with a resistivity of ρ1 and a cross section of S2 is set to ensure that the bilateral brake unit provides a braking deceleration of g2;

[0014] When the braking speed is in the range of V3 to V4, a brake winding with a resistivity of ρ1 and a cross section of S3 is set to ensure that the bilateral brake unit provides a braking deceleration of g3;

[0015] When the braking speed is in the range of V4 to 0, a brake winding with a resistivity of ρ2 and a cross section of S4 is set to ensure that the bilateral brake unit provides a braking deceleration of g4;

[0016] Among them, V1~V4 is the high-speed braking stage, V4~0 is the low-speed braking stage, and V1>V2>V3>V4, S1=S3 / 3, S2=S3 / 2, S4=S2, ρ1=5ρ2, g1~g4 transition smoothly without mutation;

[0017] According to the initial braking speed levels V1=1500km / h, V2=1000km / h, V3=500km / h and V4=300km / h, different braking intervals are selected and the braking system achieves full-range braking.

[0018] Based on the above-mentioned linear motor braking system, the interval between adjacent braking units is 2 mm; the winding resistivity ρ2 in the low-speed braking stage should be 10 to 20 times the copper resistivity; the winding section S = a (length) * b (width); in order to ensure the universality of stator punching sheets with different cross-sections, the winding width b is guaranteed to remain unchanged under different cross-sections during winding design, and the length a is adjusted to achieve variable cross-section; after embedding the wire, the empty part of the slot bottom is tightened by a gasket.

[0019] Based on the above-mentioned linear motor braking system, considering the influence of the electrical time constant e on the braking current, the high-speed section brake winding uses high resistivity ρ1 material to reduce the time constant and ensure the braking effect; the low-speed section brake winding uses ρ2 material with a slightly lower resistivity to ensure safe braking of the mover and smaller electromagnetic resistance when the mover is pulled back.

[0020] Based on the above linear motor braking system, for specific braking conditions, the braking system is arranged as follows under different initial braking speeds:

[0021] When the initial braking speed is V1, the braking system includes a braking winding with a resistivity of ρ1 and a cross-section of S1; a braking winding with a resistivity of ρ1 and a cross-section of S2; a braking winding with a resistivity of ρ1 and a cross-section of S3; and a braking winding with a resistivity of ρ2 and a cross-section of S4.

[0022] When the initial braking speed is V2, the braking system includes a braking winding with a resistivity of ρ1 and a cross-section of S2; a braking winding with a resistivity of ρ1 and a cross-section of S3; and a braking winding with a resistivity of ρ2 and a cross-section of S4.

[0023] When the initial braking speed is V3, the braking system includes a braking winding with a resistivity of ρ1 and a cross-section of S3; a braking winding with a resistivity of ρ2 and a cross-section of S4;

[0024] When the initial braking speed is V4, the braking system includes a braking winding with a resistivity of ρ2 and a cross-section of S4.

[0025] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0026] 1. Wide application range, short braking distance, innovative solution to the braking problem of ultra-high-speed linear motors. The maximum speed of linear motors currently in operation is about 600km / h, most of which are tens of kilometers long, with sufficient braking lines, and mostly adopt feedback braking, with a small braking deceleration. The structure described in this proposal can achieve smooth deceleration and stop of an object weighing hundreds of kilograms running at 1500km / h within a few hundred meters, and the braking system can flexibly set the braking range according to the initial braking speed requirements to achieve full-range braking.

[0027] 2. The braking function is integrated and modularized, with a simple structure and high reliability. The original series resistor braking structure must be connected in series with a large resistor in each braking section, and the installation space requirements of the braking resistor must be considered. The braking resistor series cable must be completed after the long stator VPI. Under low vacuum, it is difficult to achieve insulation at the cable joint. In this proposal, the braking function is integrated into the long stator module through the special design of the braking winding. The braking units are independent of each other, with high braking reliability and no need for additional space. Only the long stator module needs to be installed during on-site installation.

[0028] 3. The braking force of the mover pulling back is small, and the cost of the multi-functional vehicle is low. For the braking of the linear motor in the low-speed section, eddy current braking is usually used in the previous structure. The brake plates with different resistivities are divided into sections and connected to the end face of the long stator core. Eddy current braking can obtain a large braking force. Conversely, the electromagnetic resistance is also large when the mover is pulled back at low speed, and it is difficult to pull the multi-functional vehicle back. In this proposal, the low-speed section uses a brake winding with a resistivity of ρ2, which can meet the braking requirements within the effective length, and the electromagnetic resistance is small when the mover is pulled back;

[0029] 4. System complexity and investment cost are greatly reduced. When the linear motor adopts the feedback braking method, the inverter is required to drive and control the linear motor to accelerate to the required test speed, and control the linear motor to brake and feed back the generated energy to the power grid. This method requires the inverter to be a four-quadrant inverter, which increases the cost of the inverter and complicates the control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic diagram of the linear motor braking structure of the present invention;

[0031] Figure 2 It is a schematic diagram of the enlarged structure of the stator core in the present invention;

[0032] Figure 3 It is a schematic diagram of the enlarged structure of the stator punching sheet in the present invention;

[0033] Figure 4 It is a schematic diagram of the enlarged structure of the stator pressing ring in the present invention;

[0034] Figure 5 It is an enlarged schematic diagram of the brake winding in the present invention;

[0035] Figure 6 This is a schematic diagram of the wiring of the brake winding in the present invention;

[0036] Figure 7 Arrangement in the winding slot of the present invention;

[0037] Figure 8 It is an enlarged structural schematic diagram of the sliding mechanism in the present invention;

[0038] Markings in the figure: 1. Stator core; 2. Brake winding; 3. Short-circuit copper bar; 4. Wire clamping groove; 5. Wire clamping long groove; 11. Stator punching sheet; 12. Stator pressure ring; 13. Insulating screw; 131. Double-headed stud; 132. Nut; 133. Flat washer; 134. Insulating washer; 135. Insulating sleeve. DETAILED DESCRIPTION

[0039] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0040] Any feature disclosed in this specification (including any additional claims and abstract), unless otherwise stated, may be replaced by other equivalent or alternative features having similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0041] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "up", "down", "left", "right", etc. are based on the directions 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 device or element referred to must have a predetermined direction, be constructed and operated in a predetermined direction, and therefore cannot be understood as a limitation on the present invention.

[0042] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0043] Example 1

[0044] like Figure 1 to Figure 6 As shown, the present invention provides a technical solution:

[0045] A linear motor braking structure includes at least but not limited to a stator core 1, a brake winding 2 and a short-circuit copper bar 3; a wire clamping groove 4 cooperating with the brake winding 2 is arranged along the length direction of the stator core 1, and the short-circuit copper bar 3 is connected to the brake winding 2; the brake winding 2 is a 4Y winding as a whole, and the head and tail of each Y winding in the 4Y winding are short-circuited into a Y shape.

[0046] Based on the above structure, this solution short-circuits the multi-phase braking winding 2 into a star shape. When the permanent magnet mover slides over the stator segment, the mover magnetic field cuts the stator winding, and the induced current inside the winding generates a braking force on the mover, thereby achieving a smooth deceleration and braking stop of the mover and the model car from high speed within the braking segment.

[0047] As an example, the stator core 1 may include a stator punching sheet 11, a stator pressure ring 12 and an insulating screw 13; the stator punching sheet 11 is stacked into multiple pieces in the vertical direction to form a stator core, the stator pressure ring 12 is respectively arranged on the upper and lower end surfaces of the stator core, and the wire holding grooves 4 of multiple stator punching sheets 11 are stacked in the same direction to form a long wire holding groove 5. The stator punching sheet 11 and the stator pressure ring 12 are both provided with multiple through holes that cooperate with the insulating screw 13 along their length direction, and the insulating screw 13 is penetrated through the arrangement.

[0048] Based on the above structure, the stator core 1 of this solution provides the magnetic flux path required for the operation of the motor and bears the longitudinal force, normal force and vertical force when the motor is running, so it must have sufficient rigidity and strength; the wire clamping slot 5 in this solution is clamped with the brake winding 2;

[0049] The stator sheet 11 is the main magnetic flux path of the linear motor. In view of the ultra-high frequency operation requirements in this proposal, non-oriented cold-rolled silicon steel sheets with good high-frequency characteristics and low loss are selected. The specific structure is shown in Figure 3 As shown. There are multiple coil slots on each sheet in the stator core, and it is difficult to solve the accuracy problem with traditional compound punching dies. Only segmented punching and accurate positioning can ensure the slot size accuracy. In order to ensure that the center line and normal center line of the many long stator modules laid along the track are basically consistent in height direction, slot sample bars and L-shaped tooling are used during stacking to ensure that the core height tolerance after pressing is ≤0.5mm and the core end face flatness tolerance is 0.2mm.

[0050] The linear motor long stator module in this proposal is relatively long, and there are multiple turning conditions during the manufacturing process (turning once when off the line, turning twice when the coil end is glued, turning once when the finished product is transported, and turning once when installed on site). It is necessary to ensure that the stator core 1 has sufficient rigidity and that the core is reliably pressed to prevent the core from turning over and deforming, damaging the insulation, and preventing the risk of winding pressure breaking. A set of stator pressing rings 12 are set on the upper and lower surfaces of the stator core 1. The specific structure is shown in Figure 4 The pressing ring is made of anti-magnetic steel material, and multiple sets of tightening screw holes are evenly arranged along the length of the pressing ring. At the same time, considering that the clamping force can be transmitted to the core teeth, the width of the pressing ring is extended to the notch of the punching sheet, and the coil slot on the pressing ring is processed by laser cutting.

[0051] As an example, the insulating screw 13 may include a stud 131, a nut 132, a flat washer 133, an insulating washer 134 and an insulating sleeve 135; the insulating sleeve 135 passes through the through holes on the stator punching sheet 11 and the stator pressure ring 12, the stud screw is sleeved in the insulating sleeve 135, the nut 132, the flat washer 133, and the insulating washer 134 are respectively arranged on both sides of the stud screw and in contact with the stator pressure ring 12, so that the stator core is locked.

[0052] The stud 131 is formed by straightening cold-drawn round steel as a whole, the insulating sleeve 135 is made of epoxy phenolic glass cloth tube, and the insulating gasket 134 is a high-strength laminated glass cloth plate. The insulating gasket 134 and the insulating sleeve 135 block the current flow path between the screw and other components to prevent the screw from burning due to the flow of induced current when the motor is running, thereby affecting safe operation.

[0053] Based on the above structure, the insulating screw 13 bears the need to press the long stator module, avoiding large vibrations caused by the long stator core 1 not being pressed during operation, and large deformations during the installation and transportation of the long stator. When the core is pressed, the core is pressed according to the specified inter-sheet pressure by a hydraulic press or a special pressing tool, and lubricant is sprayed on the thread surface and the surface of the nut 132. The nut 132 is tightened in sequence according to the specified torque value when the core is under pressure. After the pressure is released, the nut 132 is spot welded to the stud, and each nut 132 is spot welded on at least one pair of sides.

[0054] The linear motor in this proposal is a 12-phase motor, and the brake winding 2 uses a single-layer, full-pitch, wave winding. The specific structure is shown in Figure 5 As shown. After the 12-phase winding lead wires are bent toward the back of the core, A1 / B1 / C1, A2 / B2 / C2, A3 / B3 / C3, A4 / B4 / C4 are staggered in 4 layers in the height direction; they are staggered in layers in the vertical direction; limited by the requirements of the pipeline space and the total height of the coil, the end of the winding has a large inclination angle after it leaves the slot. The short-circuit copper bar 3 is fixed to the winding lead wire by brazing, and the PT flaw detection is qualified after welding.

[0055] Comprehensively consider the accuracy of the coil bending size and the density of the end insulation wrapping. The winding material is copper plate, with one conductor in each slot. The same-phase windings in the same module are twisted and brazed into one through the nose end. Since there is only one conductor in each slot, the two conductors in each span of the same phase need to be staggered in the normal direction to avoid interference between the coil edges and the inability to embed the wire.

[0056] After the wire embedding is completed, the long stator module is subjected to overall VPI (dip varnish) and then dip-baked for curing. Limited by the end space requirements, the bevel gap between the ends of adjacent two-phase windings is small and cannot meet the discharge distance requirements of the low-vacuum winding. The winding ends need to be filled with glue and sealed as a whole to ensure that the bevel gap is densely filled and the motor winding will not be broken down during low-vacuum operation.

[0057] The material of the short-circuit copper bar 3 in each module is consistent with that of the brake winding 2. A total of 8 short-circuit copper bars 3 are arranged in each module. 1# copper bar connects A1 / B1 / C1, 2# copper bar connects A2 / B2 / C2, 3# copper bar connects A3 / B3 / C3, 4# copper bar connects A4 / B4 / C4, 5# copper bar connects -C1 / -A1 / -B1, 6# copper bar connects -C2 / -A2 / -B2, 7# copper bar connects -C3 / -A3 / -B3, and 8# copper bar connects -C4 / -A4 / -B4.

[0058] The short-circuit copper bar 3 is half-wrapped with a specified number of layers of mica tape according to the low vacuum insulation specification, the outer half is wrapped with a layer of low-resistance anti-corona tape, and the last half is wrapped with a layer of glass fiber tape. The overlap length between the copper bar insulation and the winding insulation should be greater than 30mm.

[0059] Example 2

[0060] like Figure 7 and Figure 8 As shown, the present invention provides a technical solution:

[0061] A linear motor braking system comprises at least a plurality of braking units spaced apart along the length direction, each braking unit comprises a symmetrically arranged braking structure, the end faces of the symmetrically arranged braking structures are aligned with each other, and the distance between the two braking structures arranged on opposite sides is adapted to the structure of the mover.

[0062] Based on the above structure, during the braking process, the braking structures on both sides of each braking unit each provide half of the braking electromagnetic resistance.

[0063] As an example, the interval between adjacent brake units is 2 mm. Considering the thermal expansion and contraction in the entire line direction, an installation gap of about 2 mm is set between the brake units. During the braking process, the 2 mm installation gap provides non-electric longitudinal positioning resistance to assist braking.

[0064] As an example, during the braking process, the winding inductance coefficient Li remains unchanged. To ensure that the electrical time constant e (Li / Ri) has the least effect on the braking current, different winding resistances need to be set according to different speed ranges to ensure that the average braking deceleration is maximized and the braking effect is optimal. The specific implementation is as follows:

[0065] When the braking speed is in the range of V1 to V2, set the brake winding 2 winding with a resistivity of ρ1 and a cross section of S1 to ensure that the bilateral brake unit provides a braking deceleration of g1;

[0066] When the braking speed is in the range of V2 to V3, set the brake winding 2 winding with a resistivity of ρ1 and a cross section of S2 to ensure that the bilateral brake unit provides a braking deceleration of g2;

[0067] When the braking speed is in the range of V3 to V4, set the brake winding 2 winding with a resistivity of ρ1 and a cross section of S3 to ensure that the bilateral brake unit provides a braking deceleration of g3;

[0068] When the braking speed is in the range of V4 to 0, set the brake winding 2 winding with a resistivity of ρ2 and a cross section of S4 to ensure that the bilateral brake unit provides a braking deceleration of g4;

[0069] Among them, V1~V4 is the high-speed braking stage, V4~0 is the low-speed braking stage, and V1>V2>V3>V4, S1=S3 / 3, S2=S3 / 2, S4=S2, ρ1=5ρ2, g1~g4 transition smoothly without mutation.

[0070] According to the level of initial braking speed (V1=1500km / h, V2=1000km / h, V3=500km / h, V4=300km / h), different braking intervals are selected and the braking system achieves full-range braking.

[0071] The reduction in kinetic energy when the mover passes through each brake unit is basically close to the energy consumed by the heating of the winding resistance. The braking force F = k*i2*r / v1. Through resistor matching, the maximum i2*r in each brake unit is ensured.

[0072] When the mover is towed back to the starting point by a trailer, the speed is relatively low, generally around 2m / s. At this time, the winding inductance is small, and the impedance is mainly composed of the winding resistance. To ensure that the induced current is small during low-speed towing, the winding resistivity ρ2 during the low-speed braking stage should be 10 to 20 times the copper resistivity.

[0073] Winding cross section S = a (length) * b (width). To ensure that stator punching sheets 11 with different cross sections are universal, the winding width b is kept constant under different cross sections during winding design, and the length a is adjusted to achieve variable cross section. After the wire is embedded, the empty part at the bottom of the slot is plugged with a pad, and the winding arrangement in the slot is shown in Figure 7 shown.

[0074] Considering the influence of the electrical time constant e (Li / Ri, the inductance coefficient Li is a physical quantity and remains basically unchanged) on the braking current, the high-speed section brake winding 2 uses a high resistivity ρ1 material to reduce the time constant and ensure the braking effect; the low-speed section brake winding 2 uses a slightly lower resistivity ρ2 material to ensure safe braking of the mover and smaller electromagnetic resistance when the mover is pulled back.

[0075] For specific braking conditions, at different initial braking speeds, the braking system is arranged as follows:

[0076] When the initial braking speed is V1 (~1500km / h level), the braking system needs to include a brake winding 2 winding with a resistivity of ρ1 and a cross-section of S1 (V1~V2 interval); a brake winding 2 winding with a resistivity of ρ1 and a cross-section of S2 (V2~V3 interval); a brake winding 2 winding with a resistivity of ρ1 and a cross-section of S3 (V3~V4 interval); and a brake winding 2 winding with a resistivity of ρ2 and a cross-section of S4 (V4~0 interval).

[0077] When the initial braking speed is V2 (~1000km / h level), the braking system needs to include a brake winding 2 winding with a resistivity of ρ1 and a cross-section of S2 (V2~V3 interval); a brake winding 2 winding with a resistivity of ρ1 and a cross-section of S3 (V3~V4 interval); and a brake winding 2 winding with a resistivity of ρ2 and a cross-section of S4 (V4~0 interval).

[0078] When the initial braking speed is V3 (~500km / h level), the braking system needs to include a brake winding 2 winding with a resistivity of ρ1 and a cross section of S3 (V3~V4 interval); a brake winding 2 winding with a resistivity of ρ2 and a cross section of S4 (V4~0 interval);

[0079] When the initial braking speed is V4 (~300km / h level), the braking system needs to include a brake winding 2 winding (V4~0 interval) with a resistivity of ρ2 and a cross section of S4;

[0080] In this way, this solution matches winding resistors of different resistivities and cross-sections according to different braking speed requirements, ensuring that the energy consumed by the brake winding 2 is close to the reduction in the kinetic energy of the mover, and the system braking effect is optimal and the system cost performance is optimal.

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A linear motor braking structure, characterized in that: At least includes but is not limited to a stator core, a brake winding and a short-circuit copper bar; a wire clamping groove cooperating with the brake winding is arranged along the length direction of the stator core, and the short-circuit copper bar is connected to the brake winding; the brake winding is a 4Y winding as a whole, and the head and tail of each Y winding in the 4Y winding are short-circuited into a Y shape.

2. A linear motor brake structure according to claim 1, characterized in that: The stator core includes stator punching sheets, stator pressing rings and insulating screws; the stator punching sheets are stacked into multiple sheets in the vertical direction to form a stator core, the stator pressing rings are respectively arranged on the upper and lower end surfaces of the stator core, the wire clamping grooves of multiple stator punching sheets are stacked in the same direction to form long wire clamping grooves, the stator punching sheets and stator pressing rings are both provided with multiple through holes cooperating with the insulating screws along their length direction, and the insulating screws are arranged to pass through.

3. A linear motor brake structure as claimed in claim 2, characterized in that: The insulating screw comprises a stud, a nut, a flat washer, an insulating washer and an insulating sleeve; the insulating sleeve passes through the through holes on the stator punching sheet and the stator pressure ring, the stud screw is sleeved in the insulating sleeve, the nut, the flat washer and the insulating washer are respectively arranged on both sides of the stud screw and contact with the stator pressure ring to lock the stator core.

4. A linear motor brake structure as claimed in claim 3, characterized in that: The brake winding is a single-layer, full-pitch, wave winding. The brake winding lead wire is bent toward the back of the core and then staggered in vertical layers. The short-circuit copper bar and the winding lead wire are fixed by brazing and passed the PT flaw detection after welding.

5. A linear motor brake structure as claimed in claim 4, characterized in that: A1 / B1 / C1, A2 / B2 / C2, A3 / B3 / C3, A4 / B4 / C4 of the brake winding are staggered in 4 layers in the height direction; the material of the short-circuit copper bar is consistent with that of the brake winding, and a total of 8 short-circuit copper bars are arranged in each brake structure; 1# copper bar connects A1 / B1 / C1, 2# copper bar connects A2 / B2 / C2, 3# copper bar connects A3 / B3 / C3, 4# copper bar connects A4 / B4 / C4, 5# copper busbars are connected to -C1 / -A1 / -B1, 6# copper busbars are connected to -C2 / -A2 / -B2, 7# copper busbars are connected to -C3 / -A3 / -B3, and 8# copper busbars are connected to -C4 / -A4 / -B4; the short-circuiting copper busbars are half-wrapped with a specified number of layers of mica tape as required by the low vacuum insulation specifications, the outer half is wrapped with a layer of low-resistance anti-corona tape, and the last half is wrapped with a layer of glass fiber tape; the overlap length between the copper busbar insulation and the winding insulation should be greater than 30mm.

6. A linear motor braking system, characterized in that: It comprises a plurality of brake units spaced apart along the length direction, each brake unit comprises a symmetrically arranged brake structure as described in any one of claims 1 to 5, the end faces of the symmetrically arranged brake structures are aligned with each other, and the distance between the two brake structures arranged on the opposite sides is adapted to the structure of the mover.

7. A linear motor brake system as claimed in claim 6, characterized in that: During the braking process, the winding inductance Li remains unchanged. To ensure that the electrical time constant e has the least effect on the braking current, different winding resistances need to be set according to different speed ranges to ensure that the average braking deceleration is maximized and the braking effect is optimal. The details are as follows: When the braking speed is in the range of V1 to V2, a brake winding with a resistivity of ρ1 and a cross section of S1 is set to ensure that the bilateral brake unit provides a braking deceleration of g1; When the braking speed is in the range of V2 to V3, a brake winding with a resistivity of ρ1 and a cross section of S2 is set to ensure that the bilateral brake unit provides a braking deceleration of g2; When the braking speed is in the range of V3 to V4, a brake winding with a resistivity of ρ1 and a cross section of S3 is set to ensure that the bilateral brake unit provides a braking deceleration of g3; When the braking speed is in the range of V4 to 0, a brake winding with a resistivity of ρ2 and a cross section of S4 is set to ensure that the bilateral brake unit provides a braking deceleration of g4; Among them, V1~V4 is the high-speed braking stage, V4~0 is the low-speed braking stage, and V1>V2>V3>V4, S1=S3 / 3, S2=S3 / 2, S4=S2, ρ1=5ρ2, g1~g4 transition smoothly without mutation; According to the initial braking speed levels V1=1500km / h, V2=1000km / h, V3=500km / h and V4=300km / h, different braking intervals are selected and the braking system achieves full-range braking.

8. A linear motor brake system as claimed in claim 7, characterized in that: The interval between adjacent brake units is 2mm; the winding resistivity ρ2 in the low-speed braking stage should be 10 to 20 times the copper resistivity; the winding section S = a (length) * b (width); to ensure that stator punchings with different cross-sections are universal, the winding width b is kept constant under different cross-sections during winding design, and the length a is adjusted to achieve variable cross-section; After embedding the wire, the empty part of the groove bottom is filled with a gasket.

9. A linear motor brake system as claimed in claim 7, characterized in that: Considering the influence of the electrical time constant e on the braking current, the high-speed section brake winding uses high resistivity ρ1 material to reduce the time constant and ensure the braking effect; the low-speed section brake winding uses ρ2 material with a slightly lower resistivity to ensure safe braking of the mover and smaller electromagnetic resistance when the mover is pulled back.

10. A linear motor brake system as claimed in claim 7, characterized in that: For specific braking conditions, at different initial braking speeds, the braking system is arranged as follows: When the initial braking speed is V1, the braking system includes a braking winding with a resistivity of ρ1 and a cross-section of S1; a braking winding with a resistivity of ρ1 and a cross-section of S2; a braking winding with a resistivity of ρ1 and a cross-section of S3; and a braking winding with a resistivity of ρ2 and a cross-section of S4. When the initial braking speed is V2, the braking system includes a braking winding with a resistivity of ρ1 and a cross-section of S2; a braking winding with a resistivity of ρ1 and a cross-section of S3; and a braking winding with a resistivity of ρ2 and a cross-section of S4. When the initial braking speed is V3, the braking system includes a braking winding with a resistivity of ρ1 and a cross-section of S3; a braking winding with a resistivity of ρ2 and a cross-section of S4; When the initial braking speed is V4, the braking system includes a braking winding with a resistivity of ρ2 and a cross-section of S4.

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