59 results about "Electromagnetic brake" patented technology

This utility model discloses a simulation device for testing the functional interface circuits of a simulating mobility scooter. It includes a controller with various functional interfaces, a plastic housing for testing the simulation interfaces, and a circuit board for interface simulation control connectors. A power enable switch, a simulated manual brake switch, an electromagnetic brake switch, a speed switching mode switch, a speed control potentiometer, an adjustable resistor mounting position, a horn, a working status indicator light, and CAN converter connector terminals are all electrically connected to the interface simulation control connector circuit board. The controller connector terminals are electrically connected to the controller with its various functional interfaces via an adapter cable. The working status indicator light is used to detect and indicate whether the operation is normal. This device simplifies and reduces the cost of testing the controller's functional interfaces and allows for simulated monitoring of the lifespan of the simulating mobility scooter's functions after functional testing.

The application discloses a kind of wind generating set electromagnetic brake splines dismounting device and dismounting method, for dismounting spline;The dismounting device includes two thrust blocks, two sliders, two fixed blocks and two adjusting screws;Two thrust blocks are respectively arranged in the opposite sides of the top of yaw motor end cover of wind generating set, and are respectively located in the opposite sides of spline;The side of each thrust block towards spline is formed with a limit structure, and the top surface of the side of thrust block towards spline is wedge surface;The side of each thrust block away from spline is formed with mounting groove;Two sliders are respectively installed in the mounting groove of two thrust blocks;Two fixed blocks are detachably installed in the opposite sides of the top of yaw motor end cover, and are respectively located outside two sliders;Two adjusting screws are respectively connected with two fixed blocks in one-to-one correspondence in horizontal direction by screw thread.This application can effectively solve the problems of limited spline dismounting space, poor centering effect, easy damage to components, insufficient universality and the like.

The utility model discloses an electromagnetic brake and drive assembly sealed with motor cooperation, and the electromagnetic brake includes the casing of one side open structure, and the casing open side is provided with the apron, and the casing is provided with armature and friction plate with apron, its characterized in that, the side of apron away from the casing is suitable for with motor cooperation, and the edge area of the side of apron away from the casing extends first flanging, and the end face of first flanging is suitable for with motor pressure, and the inner periphery of first flanging is provided with first sealing washer, wherein, the height of first sealing washer is greater than the height of first flanging. Thus, the first flanging and corresponding first sealing washer are arranged in the apron area of electromagnetic brake and motor cooperation, to seal the gap existing between the apron and motor end face. In this way, the output shaft of motor through to the first center hole of electromagnetic brake area is sealed in, can effectively prevent liquid or dust etc. from first center hole, keeps good sealing effect.

The utility model provides a kind of electromagnetic brake, the electromagnetic brake includes the shell, clutch plate, friction disc and tail plate in turn stacked along preset path, the preset path is parallel to the axial direction of the shell, the shell is equipped with the elastic member and excitation coil acting on the clutch plate;Multiple first slots extending along its radial direction are opened on the clutch plate, the opening of the first slot extends to the outer ring of the clutch plate, and penetrates the clutch plate along the axial direction of the clutch plate, so that the clutch plate is composed of multiple action pieces evenly distributed around its axis;The elastic member includes multiple brake springs, multiple brake springs are one-to-one corresponding with the action piece Setting, and for abutting on the action piece. The electromagnetic brake provided by the utility model is more uniform to the friction effect of friction disc, reduces the local wear of friction disc;Metal powder accumulation in friction area can be reduced, so as to improve the service life of friction disc.

This utility model discloses a sealed and locked photoelectric platform with anti-interference and modular disassembly, comprising a horizontal assembly, an elevation and descent assembly, and a cabin assembly. The horizontal assembly includes a horizontal axis system component, a horizontal control component, and an inertial measurement component. The cabin assembly includes a sensor component, a main shell, a front shell, and a rear shell. The elevation and descent assembly is installed on the horizontal assembly via a stop fit, and the cabin assembly is installed on the elevation and descent assembly via stop fits at both ends of the main shell, thus forming the photoelectric platform. The cabin assembly adopts a detachable sealed structure to improve airtightness and maintainability, and the horizontal assembly is equipped with an electromagnetic brake to achieve locking and unlocking functions. Each module, through shielding filtering and modular disassembly design, improves anti-interference and maintainability, meets the stable operation requirements under high humidity, electromagnetic interference, and turbulent environments, and has high economic benefits.

This invention provides an integrated vector reluctance motor drive and control device for ship hatch covers, relating to the field of motor technology. It includes a motor body, a reducer, an electromagnetic brake, a controller, and a rear cover. By installing a reducer and an electromagnetic brake at both ends of the motor body, and then enclosing the electromagnetic brake inside the rear cover, and integrating the controller within the rear cover, the integrated structure formed by the motor body, reducer, electromagnetic brake, controller, and rear cover is more compact. Furthermore, the reducer exhibits better sealing at both ends, preventing poor contact and corrosion problems caused by marine salt spray environments when applied to ship hatches.

The application discloses a damping stabilizing method of a stacking machine, and solves the problem of shaking of the existing stacking machine due to braking. The method comprises the following steps: an L-shaped upper cross beam (4) and a damping mounting bracket (7) are arranged on a vertical beam (2) of the stacking machine; a left end of the damping mounting bracket (7) is connected with a first end of a left brake arm (8) arranged along the direction of an upper track (5); a right end of the damping mounting bracket (7) is connected with a first end of a right brake arm (9) arranged along the direction of the upper track (5); a pull rod (13) is connected between the last end of the left brake arm (8) and the last end of the right brake arm (9); a damping brake wheel (10) is arranged at the middle part of the left brake arm (8); a guide wheel (11) is arranged at the middle part of the right brake arm (9); and an electromagnetic brake (12) electrically connected with a dynamic motor controller is arranged on the axle of the damping brake wheel (10). The method has the characteristics of simple and compact structure, and the mechanism runs stably.

This invention belongs to the field of wind power generation technology and discloses a braking structure for wind power generation. When the electromagnetic brake in the wind turbine fails, this structure provides redundant braking assurance for the wind turbine, significantly reducing the risk of wind turbine failure. The invention includes a main shaft, one end of which is equipped with blades. An elastic membrane with its opening facing the blades and fitted behind them is used. Airflow first blows over the blades, causing the main shaft to rotate. The airflow passing over the blades then blows onto the open elastic membrane. Under the action of the airflow load, the elastic membrane stretches and moves along the airflow direction, transmitting the wind load to a connected slider. The slider moves synchronously along the main shaft away from the blades. A brake pad installed at the end of the slider axially away from the blades continuously approaches a brake disc that is axially fixed and circumferentially rotating at the other end of the main shaft. When the wind speed is high, the brake pad in the slider makes frictional contact with the brake disc, forming a braking function. No manual intervention or additional complex wind speed monitoring and triggering devices are required to activate the brake.

A hub motor with an electromagnetic brake includes a hub motor body with a built-in brake disc. The brake disc is flexibly connected to the motor rotor within the hub motor body via an elastic component. A fixed first fixing plate is located on the left side of the brake disc, and a movable second fixing plate is located on the right side. The first fixing plate is connected to a solenoid valve via a fixing post. The second fixing plate is sleeved on the fixing post and can move left and right along the fixing post. The second fixing plate is also connected to a manual trigger for manually pulling the second fixing plate to brake or release the brake. The hub motor with an electromagnetic brake of this invention achieves a flexible connection between the brake disc and the motor rotor by setting an elastic component. The elastic component can clamp the brake disc between the two brake pads under elastic action, realizing the function of simultaneous braking by both brake pads.

The utility model discloses three cylinder magnetic engine relates to engine technical field, it includes mounting panel, and the middle part of mounting panel is provided with support frame, and the inside installation of support frame has low speed generator, and one end low speed generator side is provided with stop electromagnetic brake, and the inside of low speed generator and stop electromagnetic brake is provided with the pivot, and the outside of pivot is provided with the flywheel, and the outside of flywheel is provided with starting mechanism, and the other end pivot side end fixed mounting has eccentric shaft seat, and the outside of eccentric shaft seat is provided with magnetic field adjusting mechanism, magnetic field adjusting mechanism includes magnetic cylinder starter, eccentric connecting shaft, and the outside fixed connection of eccentric shaft seat has eccentric connecting shaft, and the outside of eccentric connecting shaft is provided with three groups of magnetic cylinder starter, and through the magnetic field intensity of magnetic cylinder starter adjustment, dynamic adjustment power output, the utility model discloses three cylinder magnetic engine through magnetic drive, has strengthened its environmental adaptability and operation convenience.

The utility model relates to the technical field of brake, provide a kind of electromagnetic brake of small outer diameter big axle hole, including stator, moving plate, brake disc and flange arranged in sequence, flange is fixedly connected with stator, it further include support screw and locating sleeve, brake disc has the through hole for the locating sleeve to pass through, support screw is used to pass through locating sleeve and the shaft shoulder connection of the power axle connection, locating sleeve limits the distance between shaft shoulder and support screw head portion.The utility model compared with prior art, can realize the basis of small outer diameter big axle hole (in the case where brake small outer diameter makes big power axle axle diameter), not prone to abnormal wear, to reduce noise, avoid jamming.

The present invention relates to an electromagnetic brake (1) or clutch comprising an electromagnet (10) arranged in a ring around a longitudinal axis (L) with a magnet housing (20) having an inner pole (14) and an outer pole (16), an armature disk (40), and a hub flange (50), wherein the armature disk (40) is movably arranged between the hub flange and the electromagnet along the longitudinal axis (L) and can frictionally interact with the inner pole (14) and / or the outer pole (16), wherein at least one first elastic damping element (60) is provided between the electromagnet (10) and the armature disk (40) and / or at least one second elastic damping element (70) is provided between the armature disk (40) and the hub flange (50) to decelerate a movement of the armature disk (40).

The application discloses a water droplet wheel with an electromagnetic brake, and belongs to the technical field of fishing reel equipment. The water droplet wheel comprises a main body frame, a line cup and a brake mechanism. The line cup is rotatably arranged in the main body frame. The brake mechanism comprises a magnetic ring, a coil and a control mechanism. The coil is arranged outside the magnetic ring. The control mechanism is provided with a variable resistor, an adjusting seat and an adjusting knob. The variable resistor is provided with a resistor body and a sliding contact. The sliding contact is slidably arranged on the resistor body and is in communication with the resistor body. The adjusting knob is rotatably arranged on the adjusting seat and is linked with the sliding contact. The variable resistor and the coil are connected in series and form a closed path. The line cup is provided with a line cup shaft. The magnetic ring is fixedly arranged on the line cup shaft. The line cup is rotated to release the line and drives the magnetic ring to rotate. The magnetic induction lines formed by the magnetic ring rotate. The coil is arranged outside the magnetic ring. The magnetic induction lines cut the coil. The variable resistor is in communication with the coil to form a closed path. An induced current is generated in the path to generate resistance to the rotation of the line cup, thereby avoiding the line explosion.

This invention discloses a control system and its circuit based on dual-axis electromagnetic brake drive, including a power supply and protection unit, a dual-axis brake drive unit, a dual-axis brake detection unit, and a drive isolation unit. Through the synergy and combination of the above units, four key technologies are formed: integrated symmetrical dual-axis drive, dual-signal redundant enable logic, isolated precision monitoring, and multi-level anti-interference protection. These technologies work together to overcome bottlenecks and achieve the goals of high-precision, high-reliability, and high-safety control. Its advantages include: (1) The symmetrical dual-channel architecture significantly reduces the timing deviation of dual-axis braking, improving positioning accuracy and equipment stability; (2) The innovative redundant logic can achieve PLD-level safety and eliminate the risk of over-cutting; (3) The use of an isolated detection unit greatly improves voltage sampling accuracy and anti-interference; (4) The circuit structure of the multi-level protection network is adaptable to more complex industrial environments.

This utility model relates to the field of brake technology and provides a dust-free enclosed electromagnetic brake, including a magnetic yoke, a moving plate, a rotor, and a flange. One end of the magnetic yoke has a mounting annular groove. The moving plate, rotor, and flange are located inside the mounting annular groove and arranged sequentially from the inside to the outside along the groove. The flange is fixedly connected to the magnetic yoke. The side wall of the magnetic yoke has an air inlet and an air outlet communicating with the inside of the mounting annular groove. The air inlet is used to connect to an air supply assembly, and the air outlet is used to connect to a dust collection container. This utility model blows air into the mounting annular groove through the air supply assembly and blows out the dust generated by rotor friction through the dust collection container, preventing a large accumulation of dust between the rotors and thus avoiding brake failure.

The application relates to an electric vehicle brake device which comprises a mounting support, a contact switch and a handle assembly; the handle assembly comprises a rotating shaft rotatably mounted on the mounting support, a rotating cam sleeved on the upper end of the rotating shaft and provided with one end, and a brake handle fixed to the rotating shaft and used for coaxially driving the rotating cam to rotate; the brake handle has an initial position and a brake position; when the brake handle is in the initial position, the rotating cam abuts against the triggering end of the contact switch, so that the driving power source keeps in a connected state; when the brake handle is in the brake position, the brake handle coaxially drives the rotating cam to rotate, so that the rotating cam is separated from the triggering end of the contact switch, the contact switch is disconnected, and the driving power source is cut off. The application has the effect of improving the problem that the electric vehicle cannot start the power source due to the failure of the electromagnetic brake device.

The utility model provides a kind of electromagnetic brake load testing equipment, belong to electromagnetic brake field, it solves the problem of the lack of test equipment of electromagnetic brake under different load when test emergency braking situation length of service life.The utility model includes pedestal and servo motor, pedestal is equipped with mounting plate one and mounting plate two, mounting plate two installs servo motor, mounting plate one installs base, base installs the brake to be measured, the rotating shaft is installed in the brake to be measured, rotating shaft installs load block, servo motor is equipped with output shaft, connecting shaft is installed between rotating shaft and output shaft, rotating shaft is equipped with fixed plate, fixed plate is inserted between load block bolt.The utility model has the advantages of;Load block is installed on the rotating shaft of the brake to be measured, the situation under emergency braking situation is simulated through servo motor and the service life of brake is detected;Load block is connected with fixed plate by bolt, can be replaced, it is convenient to detect the influence of service life of brake when emergency braking under different load.

This utility model discloses a zipline trolley with speed measurement and braking functions, relating to the field of zipline safety technology. It includes a frame, a first wheel set, a second wheel set, an encoder, an electromagnetic brake, and a controller. The first wheel set includes two first wheels mounted on the frame, used for rotating downwards along the carrying cable. The second wheel set includes a brake wheel axle and two second wheels mounted on the frame, capable of rotation, and the second wheels fixedly mounted on the brake wheel axle, also used for rotating downwards along the carrying cable. The electromagnetic brake is fixedly mounted on the frame and mounted on the brake wheel axle, capable of braking the brake wheel axle. The encoder is fixedly mounted on the frame and can detect the rotational speed of the brake wheel axle. The controller is fixedly mounted on the frame and is communicatively connected to the encoder and the electromagnetic brake. This utility model can effectively measure and control the running speed and station entry speed of the zipline trolley.

An electromagnetic brake motor, the rotor core (1) of which is formed by silicon steel sheet stacking, the upper core is embedded with several current guide bars (2), the two ends of the current guide bar are connected with the bus ring, the right end of the current guide bar is exposed from the core and is placed on the outer circle of the right bus ring, the annular magnetic yoke (9) is arranged between the right bus ring and the end surface of the core, the outer circle of the magnetic yoke is provided with a groove body accommodating the current guide bar, the right end surface of the magnetic yoke is provided with a recess accommodating the right bus ring; the disc-shaped armature is sleeved on the rotating shaft, the armature can only move axially on the rotating shaft, the inner side surface of the right end cover is connected with the friction ring, the armature is located between the magnetic yoke and the friction ring, the spring is arranged between the armature and the right end surface of the rotor, and the spring is sleeved on the rotating shaft. The beneficial effects are that the magnetic yoke is arranged on the rotor, the rotor has the function of suction disc, the energy for generating the magnetic attraction force comes from the rotor current, and no additional power consumption is generated; the armature and the friction ring are arranged in the machine shell, so that the volume of the brake motor can be reduced.

An exercise device includes a frame assembly having a flywheel support member and supporting a drive shaft adapted to be driven by a bicycle. The exercise device further includes a flywheel assembly supported by the flywheel support member and including a flywheel supported by a flywheel shaft extending through the support member. The flywheel shaft is coupled to the drive shaft such that rotation of the drive shaft drives the flywheel shaft, and the flywheel includes an outer portion and a rim that together define a flywheel volume. An electromagnetic brake assembly coupled to the support member and including an electromagnet extends within the flywheel volume to provide magnetic drag. The electromagnet can include two asymmetric outer legs. The electromagnet can be disposed inside or outside the flywheel volume.

This invention discloses an electromagnetic brake control method, device, and servo system for a servo system. The servo system includes a controller, an electromagnetic brake module, a motor drive bridge, a motor, a voltage sampling unit, a current sampling unit, and an ADC converter. The electromagnetic brake module includes a brake coil, a first switch, a second switch, a self-test circuit, and a freewheeling diode. Self-testing for open / short circuit faults in the brake is achieved by controlling the first switch to be on and the second switch to be off. After the self-test passes, the second switch is turned on, and the motor is restarted only when the coil current reaches the unlocking threshold. During operation, the duty cycle of the second switch is adjusted via PWM to maintain the coil voltage between the holding voltage and the rated voltage, reducing heat generation. Simultaneously, the coil temperature is estimated in real time based on voltage and current; if the temperature exceeds the limit, the duty cycle is automatically adjusted to cool it down. This achieves fault pre-detection, unlocking interlock, low power consumption maintenance, and safety warning, preventing motor stall and improving the safety and reliability of the servo system.

The utility model discloses a motor electromagnetic stay performance test equipment, including lower frame, upper frame, jacking mechanism, support platform, clamping structure, test table, sliding table cylinder and control module, upper frame fixed mounting is in the lower frame, jacking mechanism fixed mounting is in the lower frame, jacking mechanism, sliding table cylinder all are connected to control module through the circuit. This equipment is after the axle of wheel hub motor clamping fixed, when the sliding table cylinder reciprocatingly applies the force to the left or right to test table, whether the tire of wheel hub motor is observed to rotate, can simulate the tire stay state of wheel hub motor, the use performance of the electromagnetic brake pad acting on the wheel hub motor rotor, through setting jacking mechanism, both facilitate the axle of wheel hub motor clamping on clamping structure, can satisfy the use demand of various size wheel hub motor electromagnetic brake pad test.

The utility model relates to brake technology field provides a compact electromagnetic brake, including the stator, movable plate, rotor and flange that arrange successively, the fixed connection between flange and stator, one end of stator is equipped with recess, movable plate, rotor and flange all are in recess inside, and the target distance is left to flange outside and recess top edge. The utility model makes stator whole bowl -shaped structure, movable plate, rotor and flange all are in bowl, and flange distance bowl mouth also has target distance, cannot exceed bowl mouth or with bowl mouth level, in this way, for the compact occasion of electromagnetic brake installation between two parts, the pressure (or tension) between two parts only acts on stator, avoids flange stress and destroys brake structure stability and internal clearance precision, and then avoids thus influence brake service life.

The application provides a kind of wafer cleaning speed measuring wheel brake method and wafer cleaning device, it is applied to the speed measuring wheel being provided with electromagnetic brake, electromagnetic brake includes stator, rotor, coil winding, the side of stator close to rotor includes friction plate, rotor is fixedly connected with the rotating shaft of speed measuring wheel, method includes: first pulse current is passed to coil winding, so that coil winding magnetization, attract stator to move close to rotor direction until contact friction plate and brake;Second pulse current is passed to coil winding, so that coil winding demagnetization, stator and friction plate are separated, and the brake limit of speed measuring wheel is released.The application magnetizes coil winding by first pulse current, so that coil winding generates constant magnetic field, and electromagnetic brake does not need to be continuously energized when maintaining brake state or maintaining release state of speed measuring wheel, thereby reducing the heat output of coil winding.

The utility model provides a kind of wheel hub motor electric brake and electromagnetic brake assembly, including first shell and second shell, first shell is installed below wheel hub motor, second shell is installed below first shell;Wheel hub motor one end is clamped in first shell, wheel hub motor below is provided with clamping block and first brake disc, clamping block below is provided with fixed block, fixed groove is set up on first brake disc, fixed block is clamped in fixed groove, first brake disc below is equipped with pressure plate;Second shell is clamped in support sleeve, support sleeve below is provided with fan blade, top is provided with brake assembly, rotation block and connecting block are provided in support sleeve.The component is through brake assembly, realizes the brake operation to wheel hub motor, improves brake effect, makes vehicle travel safer;Through fan blade, can accelerate heat dissipation, reduce brake assembly heat accumulation, so that component performance is more stable.

The application discloses a caterpillar rotary cultivator tilting angle test platform, which comprises a base, an angle adjusting platform, a hydraulic cylinder, a first hinged support, a second hinged support, an arc-shaped rod, an electromagnetic brake and a brake shoe. One side of the angle adjusting platform is connected with the base through the second hinged support, the output end of the hydraulic cylinder is connected with the base through the first hinged support, the fixed end of the hydraulic cylinder is hinged with the base, the end of the arc-shaped rod is fixedly connected with the bottom of the angle adjusting platform, the electromagnetic brake is fixedly arranged on the base, and the arc-shaped rod is clamped between the brake shoes of the electromagnetic brake, so that the brake shoes can tightly hold or separate from the arc-shaped rod. The safety braking system is adopted, the arc-shaped rod is embedded between the brake shoes of the electromagnetic brake through linkage of the electromagnetic brake and the brake shoes, the brake shoes are separated when electrified, the angle adjusting platform is allowed to be flexibly adjusted in angle, the brake shoes automatically hold the arc-shaped rod through springs when power is off, the angle adjusting platform is prevented from accidentally falling, and absolute safety is ensured in the test process.

The present invention provides a control device and control program that can notify the user that the vehicle's electromagnetic brake is not released, thereby making the user aware that there is a problem with their operation. [Solution] A control device according to one embodiment controls a vehicle equipped with an electromagnetic brake that operates when the vehicle is stopped. The control device includes a controller that releases the electromagnetic brake when the user's accelerator operation changes from the off state to the on state while the electromagnetic brake is activated. The controller activates the electromagnetic brake when the stopping condition is met while the vehicle is in motion. The controller notifies the user when the accelerator operation is on while the electromagnetic brake is activated.

This invention provides a spring-driven self-resetting electric actuator, comprising a housing, a motor, and a gear assembly. The housing has a mating shaft that passes through it, with one end for mounting a self-centering connector, which in turn mounts a valve stem. The motor is mounted on the housing and has an output shaft. The gear assembly is mounted on the housing, with one end meshing with the output shaft gear and the other end meshing with the mating shaft. The motor drives the gear assembly to rotate the valve stem to open and close the valve. This spring-driven self-resetting electric actuator utilizes the motor's stall capability to brake the valve stem, eliminating the need for an electromagnetic brake. It meets the requirements for installation in both forward and reverse directions, enabling the electric actuator to simultaneously perform reset-opening and reset-closed valve functions. Furthermore, the self-centering connector can accommodate valve stems of different sizes while maintaining concentricity between the valve stem and the self-centering connector.

The application discloses a kind of adjusting member for electromagnetic brake and its use method, including loading component, the front of the loading component is centrally mounted with electromagnetic brake body, the top and bottom of the front of the loading component are symmetrically movably connected with limiting component, the back of two the limiting component is symmetrically provided with movable component, the opposite side of two the limiting component is symmetrically rotatably connected with gyro wheel, the front of two the limiting component is symmetrically movably connected with baffle, the opposite side of two the back is symmetrically fixedly connected with tightening block, the back of two the tightening block is symmetrically movably connected with movable block, the back of the loading component is installed and has adjusting component, the left and right sides of the bottom of the adjusting component are symmetrically movably connected with support column.The adjusting member for electromagnetic brake and its use method, the adjusting member is convenient for adjusting, and it is convenient to install limiting treatment to electromagnetic brake.

The utility model relates to winch technical field especially relates to a new permanent magnet frequency conversion tension winch, including base and reel, the one side of base is provided with the explosion -proof housing, the explosion -proof housing includes the first casing and second casing of integral connection, be provided with drive assembly in first casing and second casing, drive assembly includes the motor of installation in first casing, the drive end fixed mounting of motor has output shaft, be provided with speed reducer on output shaft, install electromagnetic brake in second casing. The utility model electromagnetic brake and permanent magnet motor adopt integral type arrangement, and the electromagnetic brake is installed in the tail shaft end opposite of motor output shaft, is closed in the explosion -proof housing, and the electromagnetic brake adopts magnetic force and is attracted and is disconnected, instantaneous response, action has no delay, no external speed reducer, and the permanent magnet motor is directly connected to the reel, and transmission efficiency greatly increases, can make winch rope or rope release speed reach maximization.