151 results about "Rooted tooth" patented technology

The invention provides an assembling and meshing precision adjusting method for a harmonic reducer, and relates to the technical field of reducers, the harmonic reducer comprises a flexible gear and a rigid gear with specific tooth profiles, and the tooth profile of the flexible gear comprises a first arc tooth top and a first arc tooth root; the tooth profile of the rigid gear comprises a second planar tooth top, transition arcs located at the vertex angles of the two sides of the second planar tooth top and a second arc-shaped tooth root. The elliptical wave generator is used for driving the flexible gear; the wave height of the wave generator is defined as the difference between a long half shaft and a short half shaft; the method comprises the following steps: acquiring a tooth profile parameter set of a flexible gear and a rigid gear, wherein the tooth profile parameter set comprises a first tooth crest arc radius, a first tooth root arc radius, a second tooth crest plane width and a second tooth root arc radius; based on the tooth profile parameter set, according to a preset matching relation used for optimizing the meshing performance, cooperatively determining a target wave height matched with the tooth profile parameter; and according to the target wave height, a corresponding wave generator is selected to complete the assembly of the harmonic reducer.

The invention discloses a gear pair life prediction method based on dynamic stress, belongs to the technical field of reliability design of mechanical transmission systems, and aims to solve the problem of inaccurate life prediction caused by neglecting a dynamic effect and a real surface topography in an existing gear design method. The method comprises the following steps: firstly, acquiring gear pair interface mechanical property parameters considering shafting vibration, dynamic load and surface roughness, wherein the parameters comprise transient oil film pressure, friction coefficient, oil film thickness and shear stress; solving a three-dimensional subsurface stress field by adopting an algorithm and calculating von Mises equivalent stress distribution; stress volume integration is conducted on different rough surfaces, the honed surface is used as the reference, the relative fatigue life of other surfaces is calculated based on the Zaretsky life prediction theory, and accurate prediction and process optimization of the contact fatigue life are achieved; meanwhile, the dynamic bending stress of the tooth root is calculated based on the dynamic normal load, and the bending fatigue safety coefficient is checked.

The invention provides a bionic stubble cutting knife, a bionic stubble cutting knife device and a design method, and relates to the technical field of agricultural machinery, the bionic stubble cutting knife comprises a knife disc base body and a plurality of knife teeth uniformly distributed along the circumference of the knife disc base body in the same direction, each knife tooth comprises a main cutting edge, a tooth tip, a knife back and a tooth root reinforcing rib which are connected in sequence, and the angle of the main cutting edge imitates the upper jaw of a earwig. The outer contour curve of the cutter tooth is formed by sequentially connecting a main cutting edge curve, a tooth top curve, a cutter back curve and a tooth root reinforcing rib curve in a transition mode, and the connecting points of the curves are tangent. The bionic stubble cutting knife device comprises a bionic stubble cutting knife, a connecting structure, a vibration reduction structure, a connecting spring and a driving device, and the vibration reduction structure adopts a two-stage composite vibration reduction system. Through a bionic cutting structure, a two-stage vibration reduction system and a flexible adaptive design, cooperation of efficient cutting, stable operation, cost reduction, efficiency improvement and environmental protection is achieved, a better solution is provided for agricultural stubble cutting operation, and technological upgrading of agricultural machinery equipment is promoted.

The present application relates to gear processing forging equipment technical field, specifically a kind of temperature monitoring function's gear processing is forged device, and the forging device includes first forging machine, second forging machine, manipulator, test table, first forging machine is processed into intermediate body by hollow cylindrical raw material block, second forging machine is placed in first forging machine side, second forging machine is processed into gear-shaped forming body by intermediate body, test table is placed in second forging machine side, test table tests the tooth root toughness in the meshing process of forming body, manipulator is set between first forging machine, second forging machine, test table for transferring workpiece.Raw material block is heated to forging point using resistance heating mode, resistance heating electrode is set in first forging machine and second forging machine, first forging machine and second forging machine are with infrared probe to identify the temperature of raw material block and intermediate body in heating process.After obtaining intermediate body, the outer edge of heated intermediate body, so that the material that becomes tooth surface finally in second forging process is based on the material of original outer edge.

The removable anti-loosening false tooth comprises a false tooth main body, a tooth root connecting block is arranged at the bottom of the false tooth main body through a connecting groove with internal threads, and a tooth root sleeve for performing outer protection positioning on the tooth root connecting block is arranged at a bottom port of the connecting groove and located at the bottom of the false tooth main body; through the false tooth main body, the connecting groove, the tooth root connecting block, the tooth root main body and the threaded connecting part, the false tooth main body is fixed on the threaded connecting part on the tooth root connecting block through threads of the connecting groove for connection and fixation, so that the false tooth main body and the tooth root connecting block can be quickly fixed, and the tooth root sheath is positioned and sleeved outside the tooth root connecting block for protection; according to the structural connection mode, the false tooth main body only needs to be screwed to be separated from the tooth root connecting block in the picking and replacing process, so that the worn false tooth main body can be conveniently picked and replaced, and the problem of gingival injury caused by picking and replacing by virtue of a tool is avoided.

The application discloses a high-bearing low-noise special gear precision machining process, which comprises the following steps: precision die forging and isothermal normalizing, double-reference composite finish turning, self-adaptive roll-scrub composite near-net forming, segmented and partial-pressure gradient carburizing and quenching, deep cryogenic graded aging, reference reconstruction flexible honing polishing, pulse laser shock strengthening, tooth root fillet roll strengthening, full-parameter precision detection, hierarchical selection and micro-correction. The application solves the problems of large deformation, low precision, poor fatigue and high noise in traditional processes through the synergistic control of forming-stress-precision-surface morphology, and the special tooth profile is stably up to DIN 4-5 level, the tooth surface is Ra≤0.2 microns, the fatigue life is increased by more than 60%, and the noise is reduced by 6-10 dB. The process combination is not obvious and has outstanding creativity, and is suitable for high-precision batch manufacturing of special gears of high-end equipment such as new energy vehicles and high-speed heavy-duty transmission.

The utility model provides a screw rotor and a vacuum pump. The screw rotor comprises a rotating shaft and a plurality of rotor blades, the plurality of rotor blades are sleeved on the rotating shaft; each rotor blade comprises a tooth top part, a tooth root part, a chamfer surface and an end surface; the end face is configured to be penetrated by a rotating shaft. The tooth top is provided with a tooth top surface, and the tooth root is provided with a tooth root surface; one side of the chamfered surface is connected with the edge of the tooth top surface, and the other side of the chamfered surface is connected with the edge of the end surface; the tooth root face is provided with a concave part, and the side wall of the concave part is matched with the chamfer face. According to the screw rotor, the chamfered surfaces are arranged at the tooth tops of the rotor blades, and the concave part side walls matched with the chamfered surfaces at the tooth tops are correspondingly arranged at the tooth root parts, so that the machining error caused by secondary positioning of a rotating procedure is avoided on the basis of reducing a gap in the meshing process of the screw rotor; therefore, the sealing precision of the vacuum pump is improved, and finally the working efficiency of the vacuum pump comprising the screw rotor provided by the utility model is improved.

The invention discloses a cycloidal gear tooth profile three-section modification method. The cycloidal gear tooth profile is divided into a tooth root section, a meshing area section and a tooth top section; according to the thickness of the lubricating oil film, the modification gap at the tooth root is obtained, and according to the contact deformation at the tooth crest, the modification gap at the tooth crest is obtained; and by taking the return difference and the minimum contact stress in the dynamic transmission chain precision interval as boundary conditions, the modification clearance of the meshing area is obtained, the modification clearances at the tooth root, the meshing area and the tooth top are combined, and the tooth profile of the cycloidal gear is obtained according to the modification clearance curve. Different modification gaps can be designed according to different return differences and dynamic transmission chain precision intervals. A cycloidal gear tooth profile with controllable return difference and dynamic transmission chain precision and minimum contact stress when lubrication and stable and uniform meshing of a gear pair are considered can be obtained; the method is a modification method with higher precision.

This invention discloses a gear mold, an in-cavity sensing structure, a measurement system, and a measurement method. The gear mold includes at least one mold wall constituting the gear mold cavity. The in-cavity sensing structure includes a temperature sensing component and a pressure sensing component. The temperature sensing component includes at least a plurality of probes arranged in an array along key cavity positions. The key cavity positions include at least two of the gear's tooth tip forming area, tooth root forming area, and gate area. The pressure sensing component includes at least a plurality of ejector pins arranged in an array below the gear mold cavity. One end of each ejector pin abuts against a pressure sensing element. The probes are electrically connected via lead wires passing through the mold wall, and the pressure sensing element is electrically connected via a lead wire storage portion pre-embedded in the gear mold. Through an integrated sensing array layout deeply coupled with the gear mold structure, synchronous, direct, and in-situ monitoring of multi-point temperature and distributed pressure within the cavity during the precision gear injection molding process is achieved.

This invention discloses a continuous induction hardening device for sprockets, belonging to the field of hardening technology. It includes a hardening frame filled with coolant; a hardening section installed inside the hardening frame for induction heating of the sprocket; and a loading section installed at the bottom of the hardening frame for picking up and feeding the sprocket. In this device, the induction coil is curved to match the arc-shaped tooth profile of the sprocket. The upper and lower effective heating sections correspond to the upper and lower tooth roots, respectively. The heat source preferentially acts on the thicker part of the tooth root, ensuring sufficient heat input. Simultaneously, a rotary motor drives the sprocket to rotate. For sprockets with greater thickness, a side coil can be added to assist in heating the tooth sides, avoiding the problem of overheating in the main heating zone and insufficient heating of the side walls. This improves upon existing circular induction coils where the tooth tip heating rate is much faster than the tooth root during hardening, effectively reducing the risk of hardening cracks caused by the significant difference in heating rates and improving the quality of the finished sprocket.

A vehicle seat adjustment mechanism includes a first component and a second component that is movable relative to the first component. A drive mechanism is drivingly connected to the second component for moving the second component relative to the first component. The drive mechanism includes a drive motor drivingly connected to a first gear member having conical involute teeth. A second gear member includes conical involute teeth in meshing engagement with the conical involute teeth of the first gear member. The conical involute teeth have a tapered tooth thickness, a tapered root and a tapered outside diameter.

The present invention relates to the technical field of pinion transmission, and provides a pure rolling pinion-and-rack mechanism having parabolic function-based tooth profiles and hyperbolic tooth traces, comprising a pinion and a rack. A transverse tooth profile of each of the pinion and the rack consist of a transverse working tooth profile curve and a root transition curve, and the transverse tooth profiles of the pinion and the rack are both bilaterally symmetrical; the transverse working tooth profile curves of the pinion and the rack are parabolas; the tooth surfaces of the pinion and the rack have a hyperbolic tooth trace structure; and at least one pair of tooth meshing points of the pinion and the rack are located at nodes to achieve pure rolling meshing contact, and a meshing line formed by a movement trajectory of the meshing points of the pinion and the rack form two contact lines on the tooth surfaces of the pinion and the rack, respectively. The present invention has the advantage effects that: the contact lines are axisymmetric hyperbolas after being unfolded on a pitch cylinder surface to eliminate axial force, the theoretical value of the relative sliding speed of all meshing points on the contact lines is zero, the tooth profile tooth surface is a meshing tooth surface without relative sliding, the friction loss and noise are significantly reduced, and the transmission efficiency is greatly improved.

This invention discloses a shape-free measurement method for spur gears based on a single set of line structured light. The method includes: constructing an optical platform coordinate system; calibrating the line structured light coordinate system using a spherical calibration body; calibrating the rotation center of a precision turntable; installing the spur gear under test and establishing its coordinate system; adjusting the position of the line structured light probe so that its measurement field of view covers the spur gear from the root circle to the addendum circle; mounting the spur gear on the precision turntable and driving it to rotate at a uniform speed; the line structured light probe scanning and acquiring the spur gear contour point cloud data and circular grating angle information to obtain three-dimensional point cloud data of the tooth surface; based on the three-dimensional point cloud data of the tooth surface, extracting the addendum circle, root circle, and involute tooth profile, and calculating the spur gear parameters; performing reverse three-dimensional tooth surface identification on the modified spur gear to generate a three-dimensional deviation map; outputting the measurement results and printing a report. This invention solves the problems of rapid shape-free measurement of spur gears with unknown basic parameters, tooth surface identification of modified gears, and three-dimensional deviation characterization of the tooth surface.

The application provides a gear fatigue crack propagation life calculation method and system considering random dynamic load, and the method is as follows: a local plane coordinate system is established at a crack tip, and a crack propagation equation is constructed; time-varying mesh stiffness containing a tooth root crack feature is calculated; a vibration differential equation of a gear mesh pair is constructed and solved, and dynamic meshing forces of the gear pair under different crack states are obtained; the dynamic meshing forces of the gear pair under different crack states are processed, and a load spectrum is prepared, and variable amplitude load data with multi-periodicity are obtained; the variable amplitude load data are taken as boundary conditions, crack propagation is simulated, gear fatigue crack propagation data are read from a finite element data file; stress intensity factors are calculated based on the gear fatigue crack propagation data; and fatigue crack propagation life is estimated based on the Paris formula and the stress intensity factors. The method can improve the reliability and fatigue crack propagation life of the gear, improve the safety of equipment, and reduce maintenance costs.

The invention relates to a gear, a wind generating set and a gear design method, the gear has a main rotation direction, from the cross section view of the gear, a tooth groove of the gear is provided with a working face side, a first tooth profile, a first tooth root transition curve, a second tooth profile and a second tooth root transition curve, the non-working face side is located behind the working face side in the main rotation direction, and the non-working face side is provided with a second tooth profile and a second tooth root transition curve which are connected; wherein the first tooth profile and the second tooth profile are symmetrically arranged relative to a symmetry plane, and a preset distance exists between the connection point of the first tooth root transition curve and the second tooth root transition curve and the symmetry plane. And the connection point of the first tooth root transition curve and the second tooth root transition curve is closer to the second tooth profile than the first tooth profile. According to the technical scheme, the bending fatigue strength of the working face side of the gear can be improved while the size of the gear is not increased.

The invention belongs to the technical field of laser cladding remanufacturing, and relates to a method for repairing broken tooth damage of a gear. According to the method, firstly, a machining method is adopted, after all areas of broken teeth to be repaired are removed, the broken teeth are continuously cut inwards, and a groove which is provided with a flat and defect-free bottom face and is parallel to the axis of a gear is obtained in a tooth root circle; after gear parameters are collected, a gear base body is preheated, the bottom face serves as a base face, technological parameters are determined, a scanning mode is selected for basic tooth profile cladding, cladding continues after a groove is filled, an approximately-trapezoidal basic tooth profile is obtained, and cladding allowance is reserved on the tooth side face; the relative position posture that a laser head is vertical and the tooth side face is inclined is adopted, gradient composite powder is adopted for tooth side face cladding material increase, a gradient cladding layer is obtained, the cladding allowance reserved for basic tooth profile cladding is supplemented, and the machining allowance of the tooth face is removed; and finish machining and heat treatment are conducted on the repairing layer, the precision and performance of the repaired gear are improved, and the performance of the repaired gear is inspected.

The application discloses a gear design optimization method based on a Bayesian algorithm, and relates to the technical field of gear design. A tooth surface geometric model is established based on the pure rolling relationship of a rack and a gear, a load stiffness coupling model is constructed by combining meshing partition and a tooth direction slicing method, contact and bending stress are obtained, and drive and non-drive side pressure angles, addendum height coefficients, dedendum fillet radius coefficients, radial variables and tooth widths are taken as design parameters. A multi-objective function of minimizing maximum dedendum bending stress, maximum contact stress and maximizing average overlapping degree is set. A Markov blanket structure is introduced to screen key variables, a Gaussian process is used to establish a proxy model, and an improved acquisition function based on an expected hypervolume is used for iterative optimization. The number of iterations, the improvement amplitude and the running time limit are taken as termination conditions. The optimal parameters are screened by combining a normalized comprehensive score. The gear design optimization method based on the Bayesian algorithm can improve the design accuracy of asymmetric high-overlapping gears and the efficiency of design parameter optimization.

The invention relates to the technical field of gear machining, and discloses a gear turning method of a cycloid-like internal meshing gear, which comprises the following steps of: establishing a tooth profile mathematical model based on an arc meshing line, determining a tooth crest and tooth root conjugate tooth profile equation of an external gear and an internal gear, and establishing a four-coordinate system and a spatial motion relation; an innovative variable-domain directional search coupling dichotomy algorithm is adopted, a blade curve is accurately solved on the axial section of Z = 0, and the problem of unstable calculation caused by tooth surface singular points is solved; a parameterized tool is designed, linkage cutting of the tool and a workpiece and control of cutting parameters are achieved by means of a five-axis numerical control machine tool, the precise machining effect is finally obtained, the gear bearing capacity is improved, the transmission stability is improved, the single-piece machining time is only 30 minutes, and the technical bottlenecks that a traditional method is low in machining efficiency and prone to over-cutting and under-cutting are broken through. The method is suitable for the precision transmission field of aerospace, new energy automobiles and the like, and the high-precision industrial manufacturing problem of the cycloid-like gear is practically solved.

This utility model discloses a novel disposable, tamper-proof food packaging box, comprising a bottom box and a top cover. The bottom box has an inclined wall with several inwardly folding teeth along its opening edge. The top cover has a pressing edge groove at its opening. When the top cover is inserted into the bottom box, the upper edge of the pressing edge groove is lower than the root of the teeth on the bottom box. The folding teeth of the bottom box fold over the pressing edge groove of the top cover, thereby fixing the top cover to the bottom box. This utility model achieves sealing between the bottom box and the top cover by folding the folding teeth of the bottom box over the pressing edge groove of the top cover. It is suitable for packaging foods such as rice balls, pastries, and takeout meals, preventing unauthorized opening and ensuring food safety inside the packaging.

This invention relates to the field of heat treatment technology and discloses a large-size gear heat treatment equipment, including a base with a support at the end of the base. The support has a quenching liquid tank for holding coolant, and the equipment also includes a lifting and adjusting mechanism and a heat treatment mechanism. The heat treatment mechanism includes cooling nozzles located on both sides of the bottom of the quenching liquid tank, which spray coolant onto the gear surface. The lifting and adjusting mechanism includes a height-adjustable fixing plate above the quenching liquid tank, with a clamping assembly for holding the gear and a rotation drive assembly for driving the gear to rotate on the side of the fixing plate. This invention utilizes the gear's own lifting motion to achieve seamless switching between immersion cooling and spray cooling. Immersion first uniformly cools the entire gear teeth, reducing thermal stress, and then spraying forcibly breaks the vapor film at the tooth root, ensuring that the cooling rate at the tooth root meets the martensitic transformation requirements and completely solving the problem of insufficient tooth root hardening.

The application discloses a method for determining a tooth root fillet radius of a straight bevel gear and related devices, and relates to the technical field of gear parameter calculation. The method comprises the following steps: obtaining a first calculation equation of a target included angle when the tooth root fillet radius is maximum based on the parameters of a driving gear under the condition that the driving gear is not engaged, obtaining a second calculation equation of the target included angle when the tooth root fillet is a full circular arc based on the gear parameters, and obtaining a geometric maximum value of the tooth root fillet radius based on the first calculation equation and the second calculation equation; obtaining the diameter of a starting point of engagement of the driving gear based on the parameters of the engaged gears under the condition that the driving gear is engaged with a driven gear, determining the maximum value of the engaged tooth root fillet radius based on the diameter of the starting point of engagement of the driving gear and the parameters of the engaged gears, and comparing the geometric maximum value of the tooth root fillet radius with the maximum value of the engaged tooth root fillet radius, so that the smaller value is taken as the tooth root fillet radius of the straight bevel gear. The application can solve the problems of gear engagement interference and poor gear strength.

The present application provides a kind of inner and outer tooth forming device and method of clutch hub, including die, the inside of the die is provided with reverse block for fixing blank, the upper side of the reverse block is equipped with bulging forming assembly or stamping forming assembly, the bulging forming assembly includes punch slider and driving mechanism for driving the radial movement of the punch slider, the stamping forming assembly includes punch that can be installed on press, the circumferential side of the punch is equipped with second forming part same with the shape of the internal tooth of target part, the bottom end outside of the punch is equipped with guide belt connected with second forming part;The present application has the following beneficial effects: the present application adopts bulging and stamping compound forming method, promotes the flow of blank material in the fillet portion, reduces the fillet gap at the fillet, not only effectively improves the filling quality of clutch hub class parts at the fillet, but also effectively avoids the generation of folding defects at the tooth shape inside close to the tooth root portion in the forming process.

The invention relates to a wide helical gear tooth surface contact state analysis and evaluation method based on a tooth root stress ratio. The method comprises the following steps: establishing a wide helical gear tooth surface contact stress simulation model considering axis deflection; tooth surface contact stress simulation is carried out under the condition of different axis deflection amounts, and a stress ratio and a corresponding tooth surface contact impression area are obtained; establishing a mapping relation between the stress ratio and the tooth surface contact impression area by adopting a neural network algorithm; arranging a strain gauge at the tooth root of the actual gear pair, and collecting the actual ratio of stress; the actual ratio is input into the established mapping relation, and tooth surface contact impression area prediction is obtained; and analysis and evaluation of the tooth surface contact state of the wide helical teeth are realized. According to the method, the contact mark area of the tooth surface of the gear is mapped based on the tooth root stress ratio, and the tooth surface contact state of the wide bevel gear is analyzed quickly and accurately.

The application discloses a large internal ratchet wheel machining method, which comprises the following steps: S1, rotating a machine tool B shaft; S2, tooling a ball cutter (4) installed on the machine tool B shaft accessory with any two points on a large tooth surface of a tooling slot and any one point on a small tooth surface respectively to obtain coordinate values of each tooling point in a cutter tip coordinate system; S3, according to the intersection of a tooth root virtual circle under the cutter tip coordinate system and the connecting line of the two tooling points on the large tooth surface, the intersection point constitutes the coordinate values of a tooth root vertex in the cutter tip coordinate system, and the coordinate values of the tooth root vertex in the cutter tip coordinate system and the offset of the cutter tip coordinate system relative to a part coordinate system are obtained according to a trigonometric function relationship; and S4, the offset is used for compensating the cutter tip position deviation generated by the rotation of the machine tool B shaft. The technical effect of the application is that qualified large internal ratchet wheels are machined by compensating the cutter tip position deviation and the part tooth slot phase deviation, qualified large internal ratchet wheels are machined on a machine tool by using a common ball cutter, and production cost is saved.

The present application relates to the technical field of picking elastic tooth, especially to a pepper picking elastic tooth imitating human hand, comprising: a tooth root, the tooth root is connected with a tooth section, the tooth section is connected with a tooth tip; a connecting assembly, the connecting assembly comprises a rotating connection mechanism, an adjusting mechanism and a fixing mechanism; a friction assembly, the friction assembly is arranged on the tooth root, the tooth section and the tooth tip and is used for increasing the friction of the tooth root, the tooth section and the tooth tip; a cleaning assembly, the cleaning assembly comprises an energy storage mechanism and a blowing mechanism; when the present application is used, the relative position between the tooth root, the tooth section and the tooth tip can be fixed by the fixing mechanism after the position of the tooth root, the tooth section and the tooth tip is adjusted by the rotating connection mechanism, so that the bending state of the human hand can be simulated when picking, and the picking angle can be adjusted more conveniently to adapt to the picking of different peppers.

A stator includes a stator core and a seal kit. The stator core includes a yoke part and a plurality of tooth parts. A tooth root of the tooth part is connected to the yoke part. A tooth top of the tooth part is away from the yoke part. An opening slot is formed between two adjacent tooth parts. The opening slot includes a coil slot and a flow passing slot that communicate with each other. The coil slot extends from the tooth top to the tooth root. The coil slot is configured to accommodate a stator coil. The flow passing slot extends from the tooth root to the yoke part. The seal kit is connected to an inner wall of the opening slot. The seal kit and the inner wall of the flow passing slot jointly form a flow passing passage for a coolant to flow through.

In a gear structure of a helical gear G2 forming a gear pair with a mating gear G1, a tooth tip-side chamfered portion R1 and a tooth root-side chamfered portion R2 are provided at a pair of a tooth tip-side corner portion C1 and a tooth root-side corner portion C2 having a diagonal positional relationship on a tooth surface F abutting the mating gear G1. An amount of chamfering of the tooth root-side chamfered portion R2 is set to be larger than an amount of chamfering of the tooth tip-side chamfered portion R1, thereby preventing edge contact with the mating gear G1, and achieving a long service life.

The utility model discloses a stepping motor casing pole plate structure, which comprises a pair of pole plates and a pair of casings, the two casings form a motor casing, the two pole plates are arranged in the two casings, bases of the two pole plates are overlapped and fixed together and are arranged at the center of the motor casing, and the two pole plates are arranged in the motor casing. A circle of machine shell teeth vertically extending towards the center of the motor shell is fixed to each machine shell, pole plate teeth matched with the machine shell teeth are fixed to the two pole plates, the pole plate teeth and the machine shell teeth are each in a multi-section line tooth shape, each multi-section line tooth shape comprises a tooth root, a tooth face and a tooth top, each tooth face is in an arc line shape protruding outwards from the middle, and each tooth top is in an arc line shape protruding outwards from the middle. The arc line is tangent to the linear sections, the top of the tooth surface is connected with the tooth top through a tooth surface fillet, and the bottom of the tooth surface is connected with the tooth root through a tooth surface draft angle. According to the utility model, through the smooth transition of the multi-section line tooth form and the synchronous design of the pole plate teeth and the casing teeth, the static cogging torque and the operation vibration are obviously reduced, and the requirement of a mute scene is met.

The present application relates to an electric motor. The electric motor comprises an electric motor housing and a stator core. The electric motor housing has a liquid inlet. The stator core is arranged inside the electric motor housing; the stator core comprises an annular stator yoke and a plurality of stator teeth distributed at intervals in the circumferential direction of the stator yoke, and the stator core further comprises a first end face located on one axial end and a second end face located on the other axial end. A first tooth root cooling channel extending in the axial direction of the stator core is provided at the tooth roots of the stator teeth, and the first tooth root cooling channel comprises a first inlet and a first outlet, the first inlet being arranged between the first end face and the second end face, and the first outlet being arranged on the second end face; and in the axial direction of the stator core, the liquid inlet is closer to the first outlet than the first inlet, and a first outer cooling channel bringing the liquid inlet into communication with the first inlet is formed between the electric motor housing and the stator core.