39results about How to "Limit radial displacement" patented technology

The invention relates to food crushing equipment, in particular to an ice cream juicing all-in-one machine provided with a telescopic grid crushing part. The machine comprises a base, a barrel body and an end cover, wherein the barrel body is detachably installed on the side face of the base, the end cover is detachably installed on the barrel body, a crushing screw and a squeezing barrel, food to be squeezed is pushed into the squeezing barrel by the crushing screw in the rotating process, meanwhile, the crushing screw rotates relative to the squeezing barrel, and a detachable elastic grid device is arranged at the squeezed juice outlet end of the squeezing barrel. According to the machine, the problem that the machine is difficult to clean is thoroughly solved through the detachable elastic grid device which can be detached from the squeezing device, and the detachable elastic grid device can be soaked in water to be cleaned if the detachable elastic grid device can not be thoroughly cleaned; the detachable elastic grid device can make gaps enlarged under the action of external force, the gaps return to be in an original shape after the external force is removed, and therefore fruit and vegetable residues can be very easy to clean.

The invention discloses a stationary fixture used for an axial compression stability test of a columnar bent plate. The stationary fixture comprises a down press plate, two L-shaped upright posts and multiple pairs of collets, wherein horizontal surfaces of the two L-shaped upright posts are respectively fixed on the down press plate and are located at the straight sides of two ends of a to-be-tested bent plate, and the multiple pairs of collets are fixed on the vertical surfaces in a segmental manner respectively along the straight sides of the two ends of the to-be-tested bent plate, so that the straight sides of the two end parts of the to-be-tested bent plate are clamped between the collets at two sides. The stationary fixture used for the axial compression stability test of the columnar bent plate, disclosed by the invention, has a simple structure and is suitable for testing bent plates with multiple curvatures as the clamping positions of the L-shaped upright posts and the collets are adjustable.

The invention provides a condensation type solar power generation tracking rotating disc which comprises a fixed part and a rotating part. The fixed part is composed of a chassis with a U-shaped guiding groove, a reduction motor fixed on the chassis, two worm and gear reduction boxes symmetrically fixed on the chassis, more than three studs evenly distributed on the outer side of the U-shaped guiding groove of the chassis and pressing plates assembled on the studs, wherein the reduction motor is respectively connected with driving shafts of the two worm and gear reduction boxes on the chassis through connection shafts. The rotating part is composed of a gear ring with a U-shaped guiding groove at the bottom, more than three steel balls rolling in the U-shaped guiding groove of the gear ring, and two driving gears. The two driving gears are connected with output shafts of the two worm and gear reduction boxes fixed on the chassis symmetrically, the reduction motor drives the driving shafts of the two worm and gear reduction boxes to enable the driving gears assembled on the output shafts of the worm and gear reduction boxes to rotate, and the driving gears are symmetrically meshed with inner teeth of the gear ring to drive the gear ring to rotate so as to enable the upper rotating disc integrated with the gear ring in a fixing mode to rotate.

The invention relates to a connection fitting of a household product, which comprises a fitting body and a screw, wherein the screw comprises a screw head and a screw rod, and the screw rod is dividedinto a positioning section and a connecting section; a special-shaped channel in a racket shape is arranged on the fitting body and comprises a channel in a racket plate shape and a channel in a racket rod shape; a toothed body with an expansion function is arranged on the peripheral surface of the fitting body to form a first toothed surface, and at least a pair of positioning grooves and at least a pair of clamping strips which extend to two sides are respectively arranged symmetrically in the axial direction of the first toothed surface; two inner side surfaces of the channel in the racketrod shape on the fitting body form a second toothed surface; the distance between the two toothed surfaces is slightly smaller than the external diameter of the positioning section of the screw rod;a pair of inclined third toothed surfaces are formed between the second toothed surface and the back surface of the fitting body; and the integral gradient of each third toothed surface is matched with the external form of the bottom of the screw head, and the junction of each third toothed surface and the second toothed surface is slightly higher than the positioning section of the screw rod. Thefitting body can be fixed without using any screw thread, can be quickly assembled, and has high construction efficiency and firm connection.

The invention provides a solar power generation tracking rotating table. The solar power generation tracking rotating table comprises a fixed portion and a rotating portion, the fixed portion comprises a flange ring with a V-shaped guide groove, two direct-current slowdown motors, two transmission shaft seats, more than three guide shafts and guide wheels, wherein the flange ring with the V-shaped guide groove is fixed on a base plate, the two slowdown motors are symmetrically fixed on the base plate, the two transmission shaft seats are symmetrically fixed in the flange ring with the V-shaped guide groove, the guide shafts are fixed outside the flange ring with the V-shaped guide groove, and the guide wheels are assembled on the guide shafts. The rotating portion comprises the rotating table, more than three steel balls rolling in the V-shaped guide groove, a rotating ring, a chain, two driving gears, two driven gears and sprockets, wherein the chain is fixed on the inner side of the rotating ring, and the sprockets are fixed on the driven gears. The two direct-current slowdown motors symmetrically fixed on the base plate are meshed with the driven gears on the transmission shaft seats through the driving gears to drive the sprockets to drive the chain fixed on the inner side of the rotating ring, so that the rotating portion rotates.

The invention discloses a whip restraint device and method for a high-energy pipeline. The whip restraint device comprises a bracket assembly, a first pin base, a first pin shaft, a first speed sensitive hydraulic damper, a second pin shaft, a second pin base, nuts, bolts, a plate type arc pipe clamp, a third pin base, a third pin shaft, a second speed sensitive hydraulic damper, a fourth pin shaft and a fourth pin base. Each of the parts, near the two sides of a high-energy pipeline elbow, of the high-energy pipeline is provided with one or more whip restraint device bodies. When the high-energy pipeline generates heat displacement, the speed sensitive hydraulic dampers follow the high-energy pipeline, and only small resisting force is generated to the high-energy pipeline; and when the high-temperature pipeline is broken at the high-energy pipeline elbow, the speed sensitive hydraulic dampers are locked, and due to rated resisting force formed for the high-energy pipeline, other key devices and the high-energy pipeline are effectively protected.

The invention discloses a high-energy pipeline whipping limiting system and method. The system comprises multiple groups of whipping limiting devices, wherein the two whipping limiting devices in one group are separately mounted at the two sides of a high-energy pipeline bend; and each whipping limiting device comprises a carrier assembly, a first pin seat, a first hinge pin, a speed sensitivity type hydraulic damper, a second hinge pin, a second pin seat, a nut, a bolt and a plate type arc-shaped pipe hoop. By separately mounting one group or multiple groups of whipping limiting devices on the high-energy pipelines close to the two sides of the high-energy pipeline bend, when the high-energy pipelines generate thermal displacement, the speed sensitivity type hydraulic dampers move with the high-energy pipelines, and only small resistance is produced on the high-energy pipelines; and when the high-energy pipeline bend is broken, the high-energy pipelines are locked by the speed sensitivity type hydraulic dampers, rated resistance is formed on the high-energy pipelines, and at the same time, other key equipment and the high-energy pipelines are effectively protected.

The invention discloses an automatic conveying device and method suitable for shared bicycle. A shell is arranged at the rear and upper part of a chassis. The left and right sides of the front end ofthe chassis are provided with steering wheels, and the left and right sides of the rear end of the chassis are provided with driving wheels. The driving wheels are controlled to move forward by a driving part, and the steering wheels are controlled to steer by a steering part. A flap plate is hinged in front of the shell, the front surface of the flap plate is fixedly connected with a U-shaped groove plate in the middle, and a locking device capable of locking the rear wheel of a shared bicycle is arranged between the U-shaped groove plate and the flap plate; A lifting mechanism capable of lifting and lowering the tipping plate is arranged at the rear of the tipping plate, and a camera capable of identifying the position of the shared bicycle is arranged at the side of the U-shaped slot plate; The invention uses a camera to identify the rear wheel position of the shared bicycle, and then uses an electromagnet drive to carry out clamping and a motor drive to carry out lifting and conveying, without human participation, so as to improve the conveying efficiency of the shared bicycle. The design of worm gear and worm gear in lifting mechanism has self-locking function, which solves the problem of instability of single car when carrying shared bicycle.

The invention belongs to the field of minitype mechanical pumps and discloses a liquid dynamic pressure suspension mechanical pump which comprises a volute, an impeller, an upper end cover, a brushless electric machine and a waterproof sleeve, wherein the brushless electric machine comprises an electric machine shell, a silicon steel sheet, a coil, a magnetic steel rotor, a waterproof sleeve, a rotor sleeve and a rotor rotary shaft; and when the liquid dynamic pressure suspension mechanical pump works, a radial liquid dynamic pressure bearing can be formed between the outer wall of the rotor sleeve and the inner wall of the waterproof sleeve through liquid and the radial displacement of the magnetic steel rotor can be limited. As the magnetic steel rotor has magnetism, magnetic force is generated between the silicon steel sheet and the magnetic steel rotor, and the magnetic steel rotor moves in the axial direction now. In addition, when liquid enters a gap at the upper part of the magnetic steel rotor, liquid generates upward thrust to the magnetic steel rotor, and resultant force of thrust in two directions and the magnetic force can limit the axial displacement of the magnetic steel rotor, so that non-contact suspension of the magnetic steel rotor can be realized.

The invention provides a flywheel energy storage device. The flywheel energy storage device comprises a shell; a mandrel; a first radial electromagnetic bearing; a second radial electromagnetic bearing; a first protection bearing; a second protection bearing; a motor; a flywheel; and a friction limiting piece; wherein a radial gap between a stator and a rotor of the second radial electromagnetic bearing is b; the radial clearance between the inner ring of the second protection bearing and the mandrel is a, and a is less than b; the radial gap between the stator and the rotor of the motor is c, and c is greater than b; the motor comprises a wheel body and a hub, and an annular space is formed by the inner ring wall and the outer ring wall of the hub, the friction limiting piece comprises an extending part extending into the annular space, the radial gap between the extending part and the inner and outer ring walls is d, and d is smaller than b. By arranging the friction limiting piece, radial vibration displacement of the mandrel is forcibly limited, the motor rotor is protected against friction with the motor stator, the bearing rotor of the radial electromagnetic bearing is protected against friction with the bearing stator in cooperation with the protection bearing, and the electromagnetic bearing and the motor are better protected; and the use safety and the service life of the flywheel energy storage device are ensured.

The invention discloses a compound polymeric housed metal oxide arrester. The compound polymeric housed metal oxide arrester comprises a plurality of arrester elements connected in series. Each arrester element comprises a compound housing, wherein an upper cover plate and a lower cover plate are arranged at the two ends of the compound housing, an arrester core is arranged between the upper cover plate and the lower cover plate, and a plurality of insulating rods are arranged in an inner cavity of the compound housing in the axial direction of the arrester core. Due to the adoption of the compound housings of the structure, the bending strength is increased by 50-120%, the winding degree is decreased by 30-80%, the tensile strength is improved by 100-400%, bending and stretching strength and rigidity of the compound housings are improved, the aim of applying the compound polymeric housed metal oxide arrester in occasions with high requirements for mechanical strength is achieved, radial displacement of the top end of the arrester under the effects of wire horizontal force, wind force and earthquake force is limited, stability of the mechanical structure and the core structure of the arrester is ensured, and safe running of the arrester is ensured.

The invention provides a bearing support device and a stiffness calibration system and method, and relates to the technical field of aircraft structural strength test verification. The bearing supportdevice comprises an outer bearing support which provides a first inner annular surface, wherein an annular fixed bearing is arranged on the first inner annular surface. The device further comprises an inner bearing support which provides a second inner annular surface, wherein another annular fixed bearing is arranged on the second inner annular surface. The inner and outer bearing supports are fixedly connected. Axial and radial directions of shaft members are defined by the bearing support device. According to the stiffness calibration system and method, which are provided by the invention,rigidity calibration of the outer bearing support and the inner bearing support is carried out through a load applying mechanism and a displacement gauge; the test method is simple and reliable; andthe test precision is high.

The invention discloses a high-speed rolling mill, and belongs to the field of pipe machining equipment. According to the high-speed rolling mill, the machining speed of a pipe is improved. The high-speed rolling mill comprises a frame, a rolling machine head installed on the frame and used for rolling the pipe, a core rod arranged on the frame and used for guiding pipe conveying, a core rod supporting piece arranged on the frame and used for supporting the core rod, a pipe supporting piece arranged on the frame and used for supporting the pipe, a jacking trolley slidably arranged on the frameand used for pushing the pipe to be conveyed to the rolling machine head, and a plurality of core rod holding devices used for limiting the axial displacement and the radial displacement of the corerod during conveying and machining the pipe. The jacking trolley can push the core rod supporting piece so that the core rod supporting piece can overturn in the axial direction of the pipe, and eachcore rod holding device comprises a clamping jaw capable of clamping or loosening the core rod, and a lifting oil cylinder for controlling the lifting of the clamping jaw, so that the influence on themovement of the jacking trolley is avoided.

The invention discloses a hand relieving mechanism of a parking braking cylinder. The hand relieving mechanism of the parking braking cylinder is arranged on a cylinder cover of the parking braking cylinder; the hand relieving mechanism of the parking braking cylinder comprises a hand relieving body, a pawl, a ratchet wheel bush, a first hand relieving spring, a second hand relieving spring, a hand relieving sliding sleeve, a first pawl shifting sleeve and a second pawl shifting sleeve; the ratchet wheel bush is rotationally connected to the cylinder cover; the pawl is rotationally connected to the cylinder cover through a pawl shaft; and one end of the pawl is matched with a toothed groove in the ratchet wheel bush. According to the hand relieving mechanism of the parking braking cylinder, by arranging the first pawl shifting sleeve and the second pawl shifting sleeve, the use of a torsion spring is avoided; and therefore, a problem of failure caused by too long use time brought by the torsion spring is solved; the detaching is convenient during overhauling; it only needs to detect wear capacity of a pawl rotating internal hole, two contacts, the first pawl shifting sleeve and thesecond pawl shifting sleeve; and the workload during overhauling is reduced.

The invention belongs to a motor testing structure, and particularly relates to a motor shaft voltage testing structure. The motor shaft voltage testing structure comprises an end cover arranged at a non-transmission end of a rotating shaft, an electric brush, a shaft sleeve and an electric brush fixing frame, wherein the end of the rotating shaft is installed in the end cover through a bearing; a shaft sealing ring is arranged between the end cover and the rotating shaft; an outer cover is arranged on the end face of the end cover; a penetrating hole is formed in the outer cover; the shaft sleeve penetrates through the penetrating hole to be fixed to the end face of the rotating shaft; one end of the electric brush fixing frame is fixed to the end cover, and the other end of the electric brush fixing frame extends to the shaft sleeve and is fixedly provided with an insulating sleeve; and the electric brush is arranged in the insulating sleeve and abuts against the shaft sleeve. According to the invention, the electric brush fixing frame is fixed to the end cover located at the non-transmission end, and is cooperated with the shaft sleeve extending from the end of the rotating shaft, so the electric potential of a motor shaft side can be tested in a limited space environment; and the outer cover and the shaft sealing ring ensure the internal sealing performance of the motor, the outer cover is provided with a through hole, and the shaft sleeve is led out through the through hole, so assembling can be completed in a narrow space.

The invention discloses a pile fixing system suitable for a lifting platform, and belongs to the field of lifting platforms. The pile fixing system comprises pile fixing devices, each pile fixing device comprises a locating block, a pile fixing slide block and a telescopic oil cylinder; each locating block is fixedly mounted on a platform main body of the lifting platform; each locating block and the pile leg of the lifting platform are arranged at an interval; each pile fixing slide block is slidably arranged on the platform main body; each pile fixing slide block is provided with a matching surface matched with an oblique plane of each locating block and a friction surface matched with a peripheral wall of the pile leg; one end of the telescopic oil cylinder is fixedly mounted on the platform main body; the other end of the telescopic oil cylinder is connected to the pile fixing slide block; the telescopic oil cylinder is used for driving each pile fixing slide block to slide between a first position and a second position along the corresponding oblique plane; when each pile fixing slide block is located in the first position, the friction surface and the peripheral wall of the pile leg are arranged at an interval; and when each pile fixing slide block is located in the second position, the friction surface abuts against the peripheral wall of the pile leg. The pile fixing system saves manpower.

The invention discloses a mechanical seal assembly. The mechanical seal assembly comprises a static ring assembly and a movable ring assembly; the static ring assembly comprises a static ring seat, a static ring, a corrugated pipe, a straining ring and a spring; the movable ring assembly comprises a shaft sleeve, a movable ring seat and a movable ring; a vibration reduction ring is arranged in the static ring seat and abuts against the position between the outer side wall of the corrugated pipe and the inner side wall of the static ring seat; the straining ring is arranged between the inner wall of the upper end of the corrugated pipe and the inner wall of the lower end of the static ring seat; the straining ring and the corrugated pipe are both provided with fixing grooves; and the spring is arranged in the fixing grooves. According to the mechanical seal assembly, the spring is arranged between the corrugated pipe and the straining ring, so that the situation that the spring generates radial displacement due to vibration of the static ring seat is avoided; and through the damping ring arranged between the corrugated pipe and the static ring seat, the vibration of the static ring seat is reduced, and the sealing performance and the sealing stability are improved.

The invention relates to a railway wagon power generation device, in particular to a railway wagon magnetic drive power generation device. The device comprises a generator and a bearing rear stopper assembly, the bearing rear stopper assembly comprises a bearing body, the bearing body is provided with a rear stopper, and the key technology is that a generator steel magnetic sheet is arranged in the generator, a rear stopper steel magnetic sheet is arranged on the outer wall of the rear stopper, and a protection ring is arranged on the outer wall of the rear stopper. The invention has the following beneficial effects: the steel magnetic sheet is arranged on the outer wall of the rear block composed of the bearing rear block, and the protective ring is arranged on the outer wall of the rear block provided with the steel magnetic sheet, so that the rear block can be unconditionally exchanged with the existing rear block of the axle system of the railway wagon, the original axle system structure is not changed, corresponding devices are not added, the traction resistance is not increased, and the weight of a single vehicle is not increased; and the magnetic lines of the permanent magnets are matched with the generator arranged on the bogie to form a loop nearby and are effectively coupled with the magnetic lines of the generator, so that the kinetic energy of the wagon is converted into electric energy to provide energy for electric equipment of the wagon.

The invention belongs to the field of minitype mechanical pumps and discloses a liquid dynamic pressure suspension mechanical pump which comprises a volute, an impeller, an upper end cover, a brushless electric machine and a waterproof sleeve, wherein the brushless electric machine comprises an electric machine shell, a silicon steel sheet, a coil, a magnetic steel rotor, a waterproof sleeve, a rotor sleeve and a rotor rotary shaft; and when the liquid dynamic pressure suspension mechanical pump works, a radial liquid dynamic pressure bearing can be formed between the outer wall of the rotor sleeve and the inner wall of the waterproof sleeve through liquid and the radial displacement of the magnetic steel rotor can be limited. As the magnetic steel rotor has magnetism, magnetic force is generated between the silicon steel sheet and the magnetic steel rotor, and the magnetic steel rotor moves in the axial direction now. In addition, when liquid enters a gap at the upper part of the magnetic steel rotor, liquid generates upward thrust to the magnetic steel rotor, and resultant force of thrust in two directions and the magnetic force can limit the axial displacement of the magnetic steel rotor, so that non-contact suspension of the magnetic steel rotor can be realized.

The invention discloses a mechanical structure of an ultra high voltage DC arrester. The mechanical structure comprises a plurality of arrester elements connected in series with one another and anti-corona devices arranged at the top ends of the arrester elements, wherein the arrester element comprises an arrester core body and a weatherproof umbrella cover sleeved outside the arrester core body;an enhanced mechanical structure is formed between the arrester core body and the weatherproof umbrella cover, and is a composite outer sleeve arranged between the arrester core body and the weatherproof umbrella sleeve; a plurality of insulating rods are axially arranged along the arrester core body on the inner wall of an insulating cylinder of the composite outer sleeve; and a plurality of support rings are radially arranged along the arrester core body. The mechanical structure can meet the requirements of strong mechanical strength and high shock resistance level of the ultra high voltage DC arrester, limit the radial displacement of the top end of the arrester under the action of a horizontal force of a conductor, wind power and a seismic force, enhance the strength and rigidity of the composite outer sleeve and ensure the stability of the support structures and core body structure of the arrester as well as the safe running of the arrester.

The invention discloses a low-flow-resistance pressurized plugging fluid connector which comprises a plug and a socket matched with the plug, and the front end of the plug and the front end of the socket are plugging ends. The plug comprises a first mounting shell, a first sealing ring, a first spring, a first axial sliding sealing assembly and a plug-in shell; the first axial sliding sealing assembly is assembled at the front end in the first mounting shell in a sliding manner; the socket comprises a second mounting shell, a third sealing ring group, a fourth sealing ring, a fifth sealing ring, an axial fixed sealing assembly, a third spring, a guide shell and a second axial sliding sealing assembly; by means of the structural design, in the working process, the sealing ring at the valve element at one end of the switch flow channel is exposed in fluid, and the sealing ring at the valve element at the other end is not exposed in the fluid, so that the sealing ring at the position cannot be washed away when the flow speed of the fluid is large; the service life of the sealing ring is prolonged, and the number of times of under-pressure plugging and unplugging of the connector is increased.

The invention relates to an anti-whipping energy dissipation limiting device for a high-energy pipe. The anti-whipping energy dissipation limiting device is characterized in that the device is composed of an anti-whipping energy dissipation and limiting annular restraining piece, the annular restraining piece comprises an inner ring cylinder body and an outer ring cylinder body, and a built-in annular cylinder body is embedded into the outer ring cylinder body; a high-energy pipe is sleeved with the inner ring cylinder body, the outer ring cylinder body is an external fixed connecting end to form a fixed cylinder body, and the inner ring cylinder body and the outer ring cylinder body are connected into a whole through the built-in annular cylinder body to form a radial limiting structure; the inner ring cylinder body and the built-in annular cylinder body form a nested movable connection structure, the built-in annular cylinder body and the outer ring cylinder body form a nested movable connection structure, and the built-in annular cylinder body and the inner ring cylinder body are movable cylinder bodies and form a multi-directional rotation and longitudinal limiting structure; and elastic buffer units are arranged at the gap position of the joint of the inner ring cylinder body and the built-in annular cylinder body and the gap position of the joint of the outer ring cylinder body and the built-in annular cylinder body to form a built-in damping and energy dissipation structure. The device has the advantages of preventing the fixed end and the pipeline from being damaged and the like.

The invention provides a locking device and a shell with the locking device. The locking device comprises a sliding lock and an interlocking assembly, wherein the interlocking assembly includes a first locking element and a second locking element; the axial opposite surfaces of the first locking element and the second locking element are respectively provided with a positioning rib and a positioning groove; the radial opposite surfaces of the first locking element and the second locking element are respectively provided with a first locking groove and a second locking groove; when the first locking element and the second locking element are assembled together, the positioning rib and the positioning groove are mutually matched to limit the radial displacement of the interlocking assembly; the first locking groove and the second locking groove are spliced to form a locking cavity, the axial displacement of the interlocking assembly is limited when the sliding lock is inserted into the locking cavity, thereby fixing and locking an interlocking device. The locking device realizes the fixing and locking functions through the above configuration. Meanwhile, the locking device has the advantages of simple structure, small occupied space, easy disassembly, convenient maintenance and low maintenance cost.

The invention provides a locking device and a shell with the locking device. The locking device comprises a sliding lock and an interlocking assembly, wherein the interlocking assembly includes a first locking element and a second locking element; the axial opposite surfaces of the first locking element and the second locking element are respectively provided with a positioning rib and a positioning groove; the radial opposite surfaces of the first locking element and the second locking element are respectively provided with a first locking groove and a second locking groove; when the first locking element and the second locking element are assembled together, the positioning rib and the positioning groove are mutually matched to limit the radial displacement of the interlocking assembly; the first locking groove and the second locking groove are spliced to form a locking cavity, the axial displacement of the interlocking assembly is limited when the sliding lock is inserted into the locking cavity, thereby fixing and locking an interlocking device. The locking device realizes the fixing and locking functions through the above configuration. Meanwhile, the locking device has the advantages of simple structure, small occupied space, easy disassembly, convenient maintenance and low maintenance cost.

The invention belongs to the technical field of ignition systems of automobile engines, and particularly relates to a mounting structure of an ignition coil. The mounting structure of the ignition coil comprises an ignition coil body, a high voltage end of the ignition coil body is connected with a contact spring, a rubber sleeve and an outer protective sleeve are sequentially arranged on the outer portion of the contact spring in a defining mode, a high voltage core of an ignition plug extends into the rubber sleeve and is connected with the rubber sleeve, a limiting unit is arranged in the rubber sleeve, and the limiting unit prevents the ignition plug from conducting axial displacement in the rubber sleeve. According to the mounting structure of the ignition coil, the high voltage core of the ignition plug extends into the rubber sleeve and is matched with the limiting unit, reliable connection of the ignition coil and the ignition plug is ensured, the rubber sleeve has certain elasticity so that stress applied by the ignition coil on an ignition plug ceramic body can be reduced greatly, therefore the problem of breaking off of the ignition plug ceramic body is avoided, and accordingly the reliability of assembly of the ignition coil is improved.