82results about How to "Large space" patented technology

Implant devices in the form of a vertebral body replacement for implantation within an intervertebral space between adjacent vertebrae is disclosed for immobilization and support of the adjacent vertebrae in a desired spatial relationship and for promotion of fusion by the adjacent vertebrae. Instruments for insertion and implantation of the implant devices and of fusion material such as bone graft material are disclosed. Methods are disclosed for implantation of the implant devices.

The present invention discloses an electrical connector comprising: a housing; a base body having a tongue, whose one surface is disposed with a plurality of first terminal slots and whose other surface is disposed with a plurality of second terminal slots; a first terminal assembly whose each first terminal is disposed with a leg and a contact portion slightly perpendicular to the leg, respectively, with the legs being alternately arranged; and a second terminal assembly whose each second terminal is disposed with a leg and a contact portion slightly perpendicular to the leg and then bending downward, respectively.

The invention discloses an automatic measuring method for digitalized airplane assembly. The method includes the steps of determining the transforming relationship between all coordinate systems and an assembly coordinate system through measurement preparatory work, transforming theoretical coordinate values of all detection points under the airplane coordinate system to the assembly coordinate system to obtain theoretical coordinate values of all the detection points under the assembly coordinate system, and conducting automatic searching with the theoretical coordinate values of the detection points under the assembly coordinate system as initial light pointing points of a laser scanner to obtain actual coordinate values of all the detection points under the assembly coordinate system. Through the automatic measuring method, digitalized measurement of airplane components is achieved, the problems that the size of airplane space is large, the detection points to be measured are wide in distribution area, manual light guiding at a part of detection points is difficult, and the detection points need to be measured repeatedly in the assembly process are solved, one-off manual installation of a reflector is achieved, multiple automated measurement is achieved, manpower is saved, the measurement time is shortened, and the measurement efficiency and the assembly efficiency are greatly improved.

A top gate and bottom gate thin film transistor (TFT) are provided with an associated fabrication method. The TFT is fabricated from a substrate, and an active metal oxide semiconductor (MOS) layer overlying the substrate. Source / drain (S / D) regions are formed in contact with the active MOS layer. A channel region is interposed between the S / D regions. The TFT includes a gate electrode, and a gate dielectric interposed between the channel region and the gate electrode. The active MOS layer may be ZnOx, InOx, GaOx, SnOx, or combinations of the above-mentioned materials. The active MOS layer also includes a primary dopant such as H, K, Sc, La, Mo, Bi, Ce, Pr, Nd, Sm, Dy, or combinations of the above-mentioned dopants. The active MOS layer may also include a secondary dopant.

The invention discloses a tissue engineering scaffold material for repairing cartilage defects and a preparation method thereof. The tissue engineering scaffold material is prepared by the following steps of: cleaning the spongy bone at the shoulder blade of a fresh pig; cutting the spongy bone into small blocks with diameter of between 5 and 10mm and thickness of between 3 and 5mm; degreasing, decalcifying and deproteinizing; immersing with alcohol for 30 minutes; and air-drying, wherein the decalcifying time is 6 hours. The prepared demineralized spongy bone matrix (DSBM) has the characteristics of relatively simple and convenient preparation method, and capacity of being obtained on a large scale, can be stored for a long time at a low temperature and is economic and cheap. The material can be prepared into different shapes and sizes according to the shapes of the defects to be repaired, so the material is convenient to apply. The DSBM remains a natural netlike gap structural system of the pig spongy bone, has high cellular compatibility, biocompatibility and degradability and is a very good cartilage tissue engineering scaffold material.

The invention discloses a beam combining, emitting and receiving method of lasers and a system, which belong to the technical field of photoelectricity and are used for carrying out beam combination, emission and reception on multi-beam multi-band high-power lasers. The beam combination, the emission and the reception of lasers in incidence in a plurality of directions are realized by adopting the reflection of a film at the side face of a prism, the incidence and the penetration of an end face, an optical fibre bar and a collimating mirror. The system contains a plurality of laser light sources, a multi-dimensional beam combiner, a shaper, a collimating mirror, a receiving and detecting unit and a computer system. The multi-dimensional beam combiner contains a multi-face prism and a prism holder, wherein the multi-face prism is provided with an end face and a plurality of reflecting mirror faces. A plurality of lasers are irradiated on the end face and the reflecting mirror faces of the multi-dimensional beam combiner from the periphery, the lasers of which the beams are combined are gathered on the input end face of the shaper at an aperture angle smaller than the numerical value of optical fibers, the output lasers are collimated into quasi-parallel light by the collimating mirror for irradiating a target, and the diffuse reflection lasers and the laser-induced radiation patterns of the target are received by the receiving and detecting unit positioned at the position of the focal point of the collimating mirror so as to realize the detection of the target and the acquisition of images.

The invention discloses a method for preparing a guanidine-gum fracturing-liquid nanometer cross-linking agent.The method includes the steps that sodium silicate serves as a silicon source to be hydrolyzed, surface modification is carried out with an organic silicon modifier, reactive nanometer silicon dioxide is prepared, and boric acid is loaded on the surface of the reactive nanometer silicon dioxide.According to the method, the raw materials are low in cost, the preparation technology is simple, and the cross-linking time can be controlled by adjusting the content of surface amido and the loading capacity of the boric acid; as cross-linking time is delayed, frictional resistance between fracturing liquid and a conveying pipe in the construction process can be reduced, and effective time is bought for construction while energy consumption is reduced; meanwhile, as the spatial size of the boric acid is increased, the cross-linking efficiency can be improved, the fracturing liquid has the good temperature resistance and the good shearing resistance accordingly, and gum breaking is complete.

The invention relates to a hook rod gear mechanism for parallel shaft transmission. The hook rod gear mechanism comprises a transmission pair composed of a driving wheel and a driven wheel. The axis of the driving wheel and the axis of the driven wheel are parallel to each other. The driving wheel is connected with an input shaft. The driven wheel is connected with an output shaft. Driving hook rods on the driving wheel are evenly distributed in the circumference of the cylindrical end face of the driving wheel. Driven hook rods on the driven wheel are also evenly distributed in the circumference of the cylindrical end face of the driven wheel. The driving hook rods and the driven hook rods are each in a cylindrical spiral linear shape. When the driving wheel and the driven wheel are installed, the driving hook rod and the driven hook rod in one pair are meshed, the driving wheel is driven by a driver to rotate, the continuous and stable meshing is completed through the meshed hook rods, and transmission between the two parallel shafts is achieved. The spiral linear shapes of the driving hook rods and the driven hook rods can be determined according to the installation spatial coordinate system, the transmission ratio and other parameters of the driving wheel and the driven wheel and according to the hook rod contact line equation. The hook rod gear mechanism is simple in structure, fewer in transmission mechanism part, small in size, light in weight, large in transmission ratio, stable in transmission and suitable for being applied to the fields of mini machines and micro machines.

The invention discloses a cabin door opening device for a hypersonic velocity wind tunnel experiment cabin, which is suitable for opening or closing a cabin door of a wind tunnel experiment cabin. The cabin door is a circular arc-shaped turnover cover, of which the circle center of the arc is positioned on the axial center line of a cabin body of the experiment cabin when the wind tunnel experiment cabin is in a closed state; the cabin door opening device for the hypersonic velocity wind tunnel experiment cabin comprises an elastic push-pull rod; one end of the elastic push-pull rod is connected with the circular arc-shaped turnover cover by a hinge; the other end of the elastic push-pull rod is connected with a rotating arm by a hinge; and the rotating arm is connected with a power driving mechanism by a rotating arm shaft. According to the invention, the elastic push-pull rod is respectively connected with the circular arc-shaped turnover cover and the rotating arm connected with the power driving mechanism, so that an actuating mechanism is provided for opening and closing the arc turnover cover; and the arc turnover cover adopted in the invention provides an access with a wide opening angle and a large space for the experiment cabin, so that a large-scaled experiment module conveniently gets in and out of the experiment cabin, experiment efficiency of a wind tunnel experiment of the large-scaled experiment module is improved and labor intensity in the process of the wind tunnel experiment is reduced.

An apparatus for capturing an object scene, in particular a seeking head for target-tracking missiles, such that, with a detector 86 in fixed relationship with a structure, it is possible to capture a large spatial angle. For that purpose the imaging optical system (30) has a system portion (28) facing the object scene which is pivotable with a pitch frame (24) about a pitch axis (26) perpendicular to a roll axis (18). The pitch frame (24) is mounted pivotably about the pitch axis (26) in a roll frame (16) which is supported in the structure (10) rotatably about the roll axis (18). The system portion (28) includes first beam deflection structure (36) by which the imaging beam path of the imaging optical system (30) is deflectable in a direction along the pitch axis (26). The imaging optical system (30) further includes second beam deflection structure (52) which are rotatable with the roll frame (16) and by which the deflected beam path is picked up along the pitch axis (26) and deflected in the direction of the roll axis (18). The detector (86) is arranged on the roll axis (18).

The invention relates to an intelligent football training information acquisition system and method. The system comprises a peripheral rebound assembly and at least three data acquisition cards. The peripheral rebound assembly is formed by connecting at least three rebound plates. Each data acquisition card is provided with a data acquisition controller, an impact force sensor, an acquisition card data storage, a data preprocessor and an acquisition card power supply battery. The honeycomb structure principle is used, and a space with the largest area is provided by least consumables. Meanwhile, the Internet-of-things technology and an interesting football training method are designed in the system so that teenagers can be helped to improve football training interest, and the system is suitable for families, kindergartens or middle schools or primary schools and other indoor and outdoor scenes. The teenagers can share training performances of themselves with coaches, classmates and teammates through the Internet of things and the Internet technology so as to obtain further guidance and help from the coaches, and can complete remote competitions by comparing the training performances with other classmates so as to improve learning and training interest.

The invention discloses a system for carrying out dynamic triaxial test by using high frequency circulating water pressure. The test system is formed by a dynamic compression device and a rock sample test bin. The dynamic compression device comprises a connecting rod transmission mechanism and a dynamic compression bin body (20); and the rock sample test bin comprises a pressure head (1), a sample bin body (21), a rubber bush (8) arranged in the sample bin body (21), and a pedestal (10) provided with a central hydraulic pressure hole. The test system makes a rock sample 5 simultaneously bear axial static load and hydraulic circulating load, and the active forces transmitted to the rock sample 5 from bearing parts belong to uniformly distributed load according to the Saint-Venant principle, so concentration and non-uniformity of the stress of an action end surface are avoided. Increase of the axial static load makes the rock sample be gradually destroyed in order to obtain the hydraulic triaxial strength of the rock. The test system has the advantages of obtaining of the trixial strength of the rock under high frequency action, good stability and reliability in the test result, low cost of the test process, and small destroys to devices.

The relates to a multifunctional crawler type tobacco planting and managing operation vehicle, which is composed of a tobacco planting and managing operation vehicle, a single-mouth transplanting device, a three-mouth transplanting device and a medicament sprinkling device. The tobacco planting and managing operation vehicle is a basic platform which accomplishes walking, man carrying and harvesting and provides power to the medicament sprinkling device; the single-mouth transplanting device can be combined with the tobacco planting and managing operation vehicle for completion of under-film young seedling transplantation and pond-making transplantation; the three-mouth transplanting device can be combined with the tobacco planting and managing operation vehicle for completion of above-film transplantation; and a power input system of the medicament sprinkling device is installed at a left-lower position of the tobacco planting and managing operation vehicle, and the medicament sprinkling device is mounted at the front of the tobacco planting and managing operation vehicle and used for completing sprinkling operation.

The invention discloses a combined protective cover for a linear cutting machine screw guide rail and relates to the field of combined protective covers mounted around carriages for protecting screw guide rails under the carriages. A left sliding rail (8), a left sliding rail mounting bending plate (10), a left spring (12), a right sliding rail (9), a right sliding rail mounting bending plate (11) and a right spring (13) are mounted between both sides of a front outer protective cover body (1) and a front inner protective cover body (5) as well as on both sides of a rear outer protective cover body (3) and a rear inner protective cover body (6), so that the front outer protective cover body (1) and the front inner protective cover body (5) as well as the rear outer protective cover body (3) and the rear inner protective cover body (6) are slidably connected to each other respectively, and a left connecting protective cover body (2) and a right connecting protective cover body (4) are mounted between both left and right sides of the front outer protective cover body (1) and the rear outer protective cover body (3) to form the combined protective cover for the screw guide rail under the carriage. The combined protective cover for the linear cutting machine screw guide rail is compact in structure, small in space size, free of noise and good in protection.

An air grid is constructed such that absorbing foil strips, which absorb scattered X-rays, are arranged in a direction parallel to the direction of rows of detecting elements, and that spacing between adjacent shadows among shadows of the absorbing foil strips formed on a flat panel X-ray detector (FPD) as a result of the absorbing foil strips absorbing X-rays is larger than spacing between pixels forming an X-ray image. An image data acquiring unit, a transmittance smoothing unit, a grid data acquiring unit, a shadowless pixel calculating unit, a shadow total quantity calculating unit, a transmittance correcting unit and an X-ray image acquiring unit are provided to remove the shadows with high accuracy by using corrected image data (X-ray transmittances) which constitutes a profile of shadows occurring at an actual time of X-ray imaging of a subject.

The invention discloses a servo-cylinder. According to the servo-cylinder, a grating scale is replaced b y a rolling grating; the rolling grating serves as an external displacement sensor for the servo-cylinder; a friction wheel of the rolling grating can be always tightly attached to a piston rod of the cylinder at certain positive pressure through a regulating device, relative sliding in the rolling process is avoided, and the problems of the traditional grating scale are well solved; moreover, requirements of the grating on installation reference accuracy, working stability of the cylinder and the like are reduced; the servo-cylinder is wide in range, small in spatial size, convenient to install and maintain and reliable in accuracy.

The invention discloses a tube external circle repairing device. A tool rest and a power mechanism are arranged at the left end and the right end of a small bottom plate; a main shaft of the tool rest is coaxial with the power mechanism; the small bottom plate is arranged on a small bearing plate which is a feeding mechanism; the main shaft of the tool rest is parallel to the feeding direction of the small bearing plate; a tube clamping frame and the small bearing plate are arranged on a large bottom plate; the main shaft of the tool rest is coaxial with a cambered positioning surface of a tube clamping frame mounting pedestal of the tube clamping frame; a corresponding tool setting strip is selected to adjust the position of a tool on the tool rest according to the size of a machined external circle; after the tool is arranged, the tool setting strip is taken out of a central cavity of the main shaft; a tube to be machined is fixed on the clamping frame mounting pedestal; one end of a spindle has an outer hexagonal shape, and the other end of the spindle is a clamping end; after the clamping end of the spindle is matched with the inner side of the tube to be machined, the other end of the spindle is inserted into the central cavity of the main shaft; and during machining, the spindle is in a static state, the tool rest is driven by the power mechanism to rotate relative to the spindle, and the small bearing plate is linearly fed so as to finish the machining.

The invention provides a precise three-dimension hand and human body attitude estimating method based on a single depth image; the method mainly comprises the following contents: a network model, an improved target position, system input, a voxel-to-voxel prediction network; the method comprises the following steps: firstly providing a network whole framework, using a convolution nerve network-based method to improve the target position, using a back projection technology to build the system input, finally using four structure blocks and an encoder and a decoder to form the voxel-to-voxel prediction network, wherein the four blocks comprises a volume basic block, a volume residual block, a volume lower sampling block and a volume upper sampling block. The method can solve the perspective distortion and nonlinear mapping problems, can obtain high precision three-dimension hand and human body attitude estimations, uses less time consumption, and can realize real time human body behaviorprediction and estimation.

The invention relates to an air plasma waste gas treatment device. The air plasma waste gas treatment device comprises a high-voltage alternating-current power supply, a housing, two first dielectric slabs installed on the housing and a grounding electrode arranged in the housing, wherein a waste gas inlet and a waste gas outlet are respectively formed in two ends of the housing, a high-voltage electrode is installed on each first dielectric slab and comprises a conductive tube and a capillary tube with one end extending into the conductive tube, an air inlet is formed in at least one end of the conductive tube, the conductive tube is connected with the high-voltage end of the high-voltage alternating-current power supply, the grounding electrode is connected with the grounding end of the high-voltage alternating-current power supply, and the other end of the capillary tube is communicated with the housing. The invention further relates to an air plasma waste gas treatment method. The air plasma waste gas treatment device and method have the advantages of efficient decomposition and low treatment power consumption, and a new thought is provided for industrial waste gas treatment.

The present invention comprises a gripping system that slides along a surface and a modular structure that incorporates this gripping system for performing physical exercise having a plurality of exercise places that can be used simultaneously. The sliding gripping system of the modular structure allows varying the height of the anchoring point where the exercise bands or ropes arc attached.A subject matter of the present invention is providing a station for performing physical exercise with resistance bands that is flexible, easy to user and is capable of accommodating different types of resistance bands and other exercise apparatuses that require anchorage to a physical object.

The invention relates to a super-bright polyester partially oriented yarn and a preparation method thereof. The preparation method comprises the following steps: uniformly mixing terephthalic acid, ethylene glycol, dihydric alcohol containing silicon on a main chain, a fluorine-containing binary acid, 2,2,3,4,5,5-hexamethyl-3,4-hexanediol and doped modified ZrO2 powder, sequentially carrying out an esterification reaction and a condensation polymerization reaction so as to prepare modified polyester; and preparing modified polyester POY yarns from the modified polyester melt according to a POYprocess by adopting a triangular spinneret plate, thereby obtaining the super-bright polyester partially oriented yarn. The prepared super-bright polyester partially oriented yarn is high in dye-uptake, K / S value and color fastness during dyeing, and the national degradation speed is high. According to the addition of the 2,2,3,4,5,5-hexamethyl-3,4-hexanediol and the dihydric alcohol containing silicon on the main chain, the dyeing property of fibers is improved, and due to the addition of the fluorine-containing binary acid and the doped modified ZrO2 powder, the degradation performance of the polyester is improved; and the prepared product is excellent in dyeing property and degradation property.

The invention discloses a preparation method of a guar gum fracturing fluid nano crosslinking agent with good temperature resistance. The method comprises the following steps: firstly adding inorganic titanium salt into a reaction medium at a temperature of 30 to 60 degrees centigrade, and stirring for 0.5 to 1 hour; and then adding an alkoxy silicon compound which contains reactive functional groups, and stirring for 2 to 8 hours at a temperature of 40 to 120 degrees centigrade to prepare the guar gum fracturing fluid nano crosslinking agent, wherein the mass ratio of the inorganic titanium salt to the alkoxy silicon compound to the reaction medium is 1 : (1 to 4) : (10 to 45). The preparation method disclosed by the invention is simple in preparation process, and ensures that the crosslinking time can be controlled by adjusting the loading capacity of titanium ions, the friction resistance between the fracturing fluid and borehole walls generated during construction can be reduced; and meanwhile, an organic-inorganic hybrid material with a larger spatial size structure can be formed by using the hydrolysis and self-polymerization functions of the alkoxy silicon compound, and thus the fracturing fluid with low concentration can achieve good temperature resistance.

The invention discloses a high-altitude rotation construction method for a large-scale venue steel awning, and relates to the technical field of constructional engineering. The method comprises the following steps: the steel awning is divided into a roof awning and a facade awning, and the roof awning is divided into n rotating structure units; after construction of a venue concrete main body structure is completed, the facade awning starts to be constructed, meanwhile, a horizontally-assembled supporting jig frame is installed on a stand structure, a lifting frame is installed in a venue, and three transverse linkage beams are arranged at different elevation positions of the front lifting frame; after the horizontally-assembled supporting jig frame is installed, the facade awning and the rotating structure units are assembled, and limiting devices are arranged; and lifting equipment is installed on the lifting frame, the lifting equipment and a cross-core oil cylinder are connected through a buckle cable, the rotating structure units continue to be rotationally lifted to the designed elevation, rotating hinges are packaged and welded, and then rod pieces between the rotating structure units are installed in an inlaying mode. By means of the method, the high-altitude work amount is remarkably reduced, the construction efficiency and the construction safety coefficient are improved, and the construction quality is also guaranteed.

The invention provides an internal connection structure of a semiconductor device and a manufacturing method of the internal connection structure. The manufacturing method includes the steps of forming a first medium layer on the substrate structure and covering a first layer interconnecting wire in the process of forming the inner connecting layer, wherein the first medium layer is attached to the side wall of the first layer interconnecting wire and grows in the direction away from the side wall of the first layer interconnecting wire to partially fill the interval region in a non-filling mode, so that a first air gap is formed in the first medium layer in the interval region, and the first air gap is sealed in the first medium layer; opening the first air gap to form a plurality of opengrooves between the first layer interconnecting wires, and expanding the space size of the grooves; forming a second medium layer on the first medium layer, covering the upper notch of the grooves bythe second medium layer to seal the open slot to form a second air gap, wherein the space enclosed by the second air gap is larger than the space enclosed by the first air gap, so that an air gap with a larger size can be formed between every two adjacent interconnecting wires to realize effective and reliable isolation between the interconnecting wires.

A vehicle seat is provided. The vehicle seat includes: a seat cushion including a seating part, a front leg which is rotatably attached to the seating part at a front side, and rear legs which support a rear side of the seating part; and a seatback is provided rotatably to the rear side of the seat cushion. The front leg is rotatably attached to a vehicle floor, the rear legs are detachably attached to the vehicle floor, and the vehicle seat is adapted to be arranged into a seating mode and a storage mode. In the seating mode, the seatback is locked on the seat cushion in an upright state, and the rear legs are locked on the vehicle floor, and in the storage mode, the seat cushion is turned forward by unlocking the lock on the seatback and the locks on both of the rear legs.

The invention relates to the technical field of biomedical material preparation, in particular to a preparation method of high-strength degradable porous biological ceramic. According to the method, light calcined calcium powder is self-made and mixed with biological glass powder, polystyrene foam microspheres are doped, the mixture is soaked in a paraffin section solution, and high-solid-phase slurry is obtained; hot-pressing molding is carried out to obtain a green body, and the degradable biological ceramic is obtained after the green body is subjected to deparaffinage, pore forming and sintering. Channels communicated with one another are reserved after ignition loss of the foam microspheres and are controlled according to the contact compact degree between the microspheres, and the larger the contact area of biological matter and the biological ceramic is, the more the strength of the biological ceramic is improved. The porous ceramic is of a special structure, and cell adhesion growth, extracellular matrix deposition, entering of nutrition and oxygen and the like are facilitated; the light calcined calcium powder is easy to biodegrade, so that the porous biological ceramic has relatively good degradation performance and has wide application prospects in the aspect of inducing bone regeneration.

A composite paper for embroidering, printing, foil coating and embossing on a same surface is provided. The composite paper is comprised of a top layer of printable paper, a middle layer of non-woven polyester felt coated with anhydrous thermoplastic glue, and a bottom layer of paper. The three layers of materials are overlapped and pressed up to 1.5 atm at 150° C. for 5 sec to form a composite paper. The composite paper of the current application is tear resistant. It is especially useful as an embroidering substrate and useful in the manufacture of cards and packaging materials that require various decorations of printing, embossing, foil coating and embroidery on a same surface.

The invention discloses a storage goods updating method and device and a logistics system, and belongs to the technical field of logistics storage. The method comprises the steps of receiving an ordersent by a first warehouse end; generating a picking task of the tray and a shelving task of each transport box on the tray according to the order information, and issuing the picking task to a secondwarehouse end, or issuing the picking task to an autonomous mobile carrier of the second warehouse, and issuing the shelving task to the second warehouse end; and generating a carrying task accordingto the inventory information of the first warehouse, and issuing the carrying task to the first warehouse end, or issuing the carrying task to an autonomous mobile carrier of the first warehouse. According to the method, the device and the logistics system provided by the invention, the shelving of the first warehouse is moved forwards to the second warehouse for shelving. The shelving and warehousing processes of the first warehouse are optimized, the efficiency of the first warehouse is improved, the picking efficiency of subsequent shipment can be effectively ensured by the first warehouse. Meanwhile, the efficiency of the whole supply chain is effectively improved, and the whole cost is reduced.

The invention discloses a planet gear tooth side gap adjusting mechanism. A planet carrier of the mechanism can adjust the distance of two pairs of adjacent planet gear shafts. A spoke type planet carrier hub of the mechanism is slotted in the radial direction, and screws are arranged in the direction vertically intersecting with a groove. Elastic deformation of the spoke type planet carrier happens through tightening of the screws, accordingly the distance between every two adjacent planet gear shafts is reduced, so that the tooth side gap between every two adjacent planet gears and a sun gear is reduced in the opposite direction, when the sun gear rotates forwards or reversely, bearing is conducted through different pairs of planet gears, and the gear return error is greatly reduced on the premise that the meshing gap of the pair of gears is guaranteed. By means of the planet gear tooth side gap adjusting mechanism, the planet gear speed reducer tooth side gap adjustment is more convenient, and meanwhile the transmission precision of a speed reducer is improved on the premise of the equal component machining precision.