90results about How to "Reduce assembly stress" patented technology

The invention discloses a micro-stress assembly flexible supporting method of a small-calibre micro-crystal glass material reflector. The method comprises the following steps of: firstly, carrying out lightweight processing on the back of the reflector, and processing a central column in the centre of the back; secondly, processing a flexible core shaft having an equilateral triangular structure, processing a hollow cylinder in the middle of the flexible core shaft, respectively processing a connecting part having a cuboid structure at three angles, processing three rectangular through holes between the cylinder and the connecting part, and processing a flexible discharging groove, a mounting hole and a pin hole in the connecting part; and finally, directly bonding and fixing an outer surface of the cylinder of the flexible core shaft with an inner surface of the central column at the back of the reflector. By the method, the positioning accuracy of the reflector is improved integrally, temperature adaptability is improved, a forced environment of the reflector during assembly is improved, and optical aberration such as field curvature and astigmatism generated by compression in the conventional mode is eliminated.

The invention relates to a diffusion welding method of dissimilar metal. A specially designed outer side limiting tool and an inner support tool are adopted for thermal expansion constraint in the welding process of an assembled to-be-welded dissimilar metal part, thus, sufficient and even welding pressure on the radial welding face is obtained, and reliable welding guarantee is provided for diffusion welding of the dissimilar metal. The expansion constraint pressurizing idea is provided by the invention for dissimilar metal interface radial pressurizing, radial expansion of the to-be-welded part is constrained through an inner side limiting tool and the outer side limiting tool, and axial expansion of the to-be-welded part is constrained through axial pressure applied by a diffusion welding device or tool, so that expansion pressure is effectively applied to the welding interface of the dissimilar metal, and the dissimilar metal weld part with good joint performance and airtightness is obtained; and the seaming condition of the whole welding interface is good, obvious concentration gradient of the welding interface exists, and the diffusion characteristic is met.

A space camera reflecting mirror center support device relates to the technical field of a space camera. The space camera reflecting mirror center support device solves the problem of a poor reflecting mirror surface deformation resulted from a large adhesion area, which exists in an existing reflecting mirror support structure, of a reflecting mirror, the problem of low installation precision resulted from poor axial and radial positioning, which exist in the existing reflecting mirror support structure, when the reflecting mirror and the support structure are adhered, and other problems. The space camera reflecting mirror center support device comprises a flexible support structure, and the flexible support structure is directly obtained through a machining mode; the flexible support structure comprises a support structure and three flexible structures uniformly distributed in the circumferential direction of the support structure; and a reflecting mirror is accurately positioned and installed, and, through design of six glue grooves, adhesive stresses are small, and an influence of assembly on a surface shape of the reflecting mirror is reduced. Through design of multiple radial and axial flexile links, dynamic structural rigidity and static structural rigidity are guaranteed, influences of a borne force and a deformation of a machine body of the space camera on the reflecting mirror can be effectively eliminated, and influences of a temperature change, the gravity and other factors on the surface shape of the reflecting mirror are reduced.

The invention relates to an axial main lens support mechanism for a vehicle-mounted self-adapting optical imaging telescope and belongs to the field of large-diameter self-adapting optical imaging detection. The mechanism solves the technical problems of low inherent frequency and low overall rigidity. The axial main lens support mechanism comprises balance mechanisms, main lenses and a main lens chamber, wherein the balance mechanisms comprise balance components and balance levers; each of the two ends of each balance lever is fixedly connected with one balance component respectively; the balance mechanisms are uniformly distributed and fixedly connected into the main lens chamber circumferentially via column articulation components and the balance levers; and the main lenses are located on the balance mechanisms. The mechanism is compact in structure, good in system rigidity, high in structural space utilization rate, small in assembly stress and high in locating accuracy, and surface shapes of the main lenses have small influence.

The invention discloses a multi-corrugation one-time forming device of an EGR pipe. The one-time forming device comprises two corrugation forming half cylinders surrounding the EGR pipe. The two corrugation forming half cylinders are correspondingly provided with forming half-cylinder mold combining devices respectively. Corrugation forming half grooves and corrugation top forming holes are formed in the inner walls of the two corrugation forming half cylinders. Corrugation top limiting molds are oppositely arranged on the outer sides of the corrugation forming half cylinders. Corrugation top limiting inserting pieces corresponding to the corrugation forming holes are arranged on the inner walls of the two corrugation top limiting molds respectively. The two corrugation top limiting molds are each connected with a limiting drive device. Forming half cylinder ejecting devices are arranged at the side portions of the two corrugation forming half cylinders respectively. A corrugation pressure forming device is arranged between the two corrugation forming half cylinders. One-time forming of multiple independent corrugations is achieved, consistency of the sizes such as the corrugation outer diameter, the corrugation outer outline and the length is effectively guaranteed, and the reliability of the EGR pipe is improved. Meanwhile, the production efficiency of the EGR pipe is greatly improved. The rejection rate and the assembling stress of the EGR pipe are greatly reduced.

The invention discloses a digitized correcting method for the assembly deformation of aircraft panels based on a six-shaft numerical control positioner. In the digitized correcting method, the relation between the motion parameter of the six-shaft numerical control positioner and the position error data of a detection point is built by a partial least squares regression inversion modeling method to obtain a digitized correcting model, so that the digitized correction of the assembly deformation of the panels of the large aircraft is realized, the assembly stress generated due to the assembly deformation of the large aircraft panels is effectively reduced, at the same time, the attitude adjustment and the butt joint with high effects and high precision for each panel during the assembly of the fuselage are ensured, and the assembly quality of large parts of the aircraft are finally improved. Through the coordinate movement of the six-shaft numerical control positioner, the digitized correcting method has the advantages that the problems of the assembly deformation correction and the accurate positioning of the panels of the large aircraft are successfully solved, the assembly stress generated by the assembly deformation of the large aircraft panels is effectively reduced, and the assembly quality of the large parts of the aircraft are improved.

The invention discloses a digitizing correction method for aircraft panel assembling deformation based on a triaxial numerical control locator. The digitizing correction method comprises the steps that the relation between location error data of the motion parameter and detection point of the triaxial numerical control locator is built through a partial least squares regression inverting modeling method to obtain a digitizing correction model, digitizing correction of the large aircraft panel assembling deformation is achieved, assembling stress caused by assembling deformation on a large aircraft panel is effectively reduced, meanwhile, efficient and high-precision posture adjusting and butt joint of all panels in the fuselage section assembling process are guaranteed, and finally the assembling quality of large aircraft parts is improved. According to the digitizing correction method, the problem of correction and accurate locating of the large aircraft panel assembling deformation is successfully solved through the coordinate movement of the triaxial numerical control locator, the assembling stress caused by the assembling deformation to the large aircraft panel is effectively reduced, and the assembling quality of the large aircraft parts is improved.

The invention relates to a flexible assembly robot with an autonomous navigation positioning function. The flexible assembly robot comprises a movable chassis, a control unit, a navigation device, a first binocular camera and a Stewart parallel robot which are arranged on the chassis, and the navigation device is composed of a laser radar, an inertial navigator and a second binocular camera; the second binocular camera is used for collecting environment point cloud data, the first binocular camera is used for collecting a three-dimensional model and pose information of a to-be-assembled workpiece, and the Stewart parallel robot is used for bearing the to-be-assembled workpiece and is provided with a first pressure sensor used for measuring the weight of the workpiece and a second pressuresensor used for measuring assembly environment force; and the control unit is used for controlling the chassis and the Stewart parallel robot to execute corresponding actions in combination with related data acquired by the navigation device, the first binocular camera, the first pressure sensor and the second pressure sensor. According to the flexible assembly robot, the operation space range ofthe assembly robot can be effectively widened, and assembly stress can be reduced or stress-free assembly can be achieved.

A three-piece jewel case for information storage discs, such as CDs and DVDs, is of the clam-shell type, and includes a base portion having a pair of generally rectangular hinge recesses positioned at adjacent corners along a rear side edge thereof, a lid portion having a pair of generally rectangular hinge arms positioned at adjacent corners along a rear side edge thereof, and a media tray having a lid portion supporting hub, which snaps into the base portion. For a preferred embodiment of the case, the media tray is hingeably connected to the base portion along the rear side edge. Each hinge arm has a rectangular solid component that extends from the outer edge to the inner edge and from the front edge to the back edge thereof. This feature rigidifies the rectangular hinge so that it is much more resistant to mechanical damage from crushing or dropping loads.

The invention relates to a slotted cylinder variable frication damper which can be applied to building structure vibration reduction control and engine vibration reduction. The damper comprises a cylinder barrel, a frictional ring and a sliding axle, wherein a vertical slot is arranged at the middle part of the cylinder barrel; the internal diameter of the cylinder barrel is equal everywhere; the frictional ring is arranged in the vertical slot of the cylinder barrel and aligned with the center of the vertical slot; the size of the vertical slot along the length direction of the cylinder barrel is larger than the axial length size of the frictional ring; the external diameter of the frictional ring is slightly larger than the internal diameter of the cylinder barrel; the frictional ring has the compressibility; the cylinder barrel has the expansibility; the axes of the frictional ring and the sliding axle are superposed and connected into a whole; and one side of both end surfaces of the frictional ring facing towards the inner wall of the cylinder barrel is provided with a circular arc chamfer. The damper can simultaneously meet the vibration reduction requirement during the strong vibration and the weak vibration of building structure.

A fastener for connecting a first part (54) having a first hole to a second part (52) having a second hole, comprising a retainer (10) having at its end A radial flange (14) and a shank (16) of square or rectangular cross-section. This shank (16) can be inserted into a second hole of the second part to abut against a corresponding side of the second part. A nut (12) is at least partially received axially within the retainer and is rotatable from a first rotational position within the retainer to a second rotational position. The nut (12) has an axially drilled hole to accommodate a set screw (56) and includes on its outer side diametrically opposite wing elements (46) which, when the nut is rotated from a first rotational position to a second rotational position, the wing elements (46) ) will be pulled due to the set screw (56) resting against the outside of the second part, the head (58) of the set screw (56) pressing against the first part (54) and pressing the latter against the retainer flange.

The invention discloses a supporting system and a supporting method for tender broken roofs of coal roadways. The supporting system is characterized in that each support canopy frame comprises two upper canopy legs, two lower canopy legs, a top transverse beam and an arched support beam, the upper ends of the two upper canopy legs of each support canopy frame are fixedly overlapped with the top transverse beam of the support canopy frame, the lower ends of the two upper canopy legs of each support canopy frame are overlapped with the upper ends of the two lower canopy legs of the support canopy frame and then are fastened and connected with the upper ends of the lower canopy legs by clamp cables, the arched support beams are arranged below the top transverse beams, the middles of the arched support beams are overlapped with the middles of the top transverse beams, and two ends of each arched support beam are overlapped with the two corresponding upper canopy legs and then are fastenedand connected with the two upper canopy legs by clamp cables; a metal support net is arranged on the upper portions of the top transverse beams of the multiple support canopy frames, the lower canopylegs of the multiple support canopy frames are fastened and connected with one another by side connectors, and the top transverse beams of the multiple support canopy frames are fastened and connectedwith one another by top connectors. The supporting system and the supporting method have the advantages that the supporting system has excellent setting load, high resistant force can be continuouslyprovided, accordingly, roadway surrounding rock can uniformly deform and can collaboratively deform with surrounding rock, and effects of supporting the coal roadways can be realized.

A three-piece jewel case for information storage discs, such as CDs and DVDs, is of the clam-shell type, and includes a base portion having a pair of generally rectangular hinge recesses positioned at adjacent corners along a rear side edge thereof, a lid portion having a pair of generally rectangular hinge arms positioned at adjacent corners along a rear side edge thereof, and a media tray having a lid portion supporting hub, which snaps into the base portion. For a preferred embodiment of the case, the media tray is hingeably connected to the base portion along the rear side edge. Each hinge arm has a rectangular solid component that extends from the outer edge to the inner edge and from the front edge to the back edge thereof. This feature rigidifies the rectangular hinge so that it is much more resistant to mechanical damage from crushing or dropping loads.

The invention relates to a cooling and sterilizing process for a protein preparation and a special horizontal type shaking table thereof. In the prior art, a sterilizing device for the protein preparation has the defects of poor stability and difficult control of parameters. The special shaking table comprises a cycloidal pin wheel speed reducer, a driving motor and a shaking table, wherein an eccentric outer gear, an eccentric inner gear, a gear shaft sleeve and a left gear base are fixedly arranged on the cycloidal pin wheel speed reducer and an output shaft of the driving motor; the left gear base is connected with one end of a regulating lead screw; the other end of the regulating lead screw is connected with a right bearing base; a shaking amplitude adjustment device is connected with the bearing base and one end of a shaking oscillating bar; the other end of the shaking oscillating bar is connected with one end of a rotating shaft of the shaking oscillating bar; and the other end of the rotating shaft of the shaking oscillating bar is connected with the shaking table by a transmission device in a shaking table cylinder body. The special horizontal type shaking table has a reasonable and compact structure, is reliable in strength, rigidity and toughness of key positions, small in assembly stress of parts and high process performance, process parameters are easy to control, and the optimal bacteriostatic effect can be achieved.

The invention relates to a front suspension support. The front suspension support comprises a U-shaped support seat. The upper portions of side plates on the two sides of the U-shaped support seat are each provided with a transverse through hole, and the through holes in the two side plates are coaxial and are the same in size. The lower portion of the front end face of the U-shaped support seat is provided with a transversely formed first rivet groove. A front-right installation block is matched in the first rivet groove. The rear end face of the front-right installation block is provided with a first rabbet matched with the first rivet groove. The front-right installation block is provided with a first installation hole of which the axial direction is in the vertical direction. According to the front suspension support, a combined type support is adopted, on the one hand, the assembly stress is lowered, and the phenomenon that after the assembly stress is relieved gradually, due to the influence of the vibration of an engine, suspension is disturbed and damaged is avoided. On the other hand, through the adoption of the combined support, the relative positions of all installation holes of the suspension support can be subjected to fine adjustment, thus the requirements for machining precision of the holes are lowered, the production cost is reduced, through replacement of all subdivisions, the maintenance cost of the whole suspension support can be reduced.

The invention discloses an aircraft structural part positioning unit in-place method based on hybrid control, and relates to the technical field of digital assembly of large structural parts. The problem that a traditional locating method is not high in locating precision is solved. The method specifically comprises the following steps: measuring the pose of an aircraft structural part through a laser tracker, and determining hybrid control parameters by constructing a transmission model of a force control shaft; enabling a ball socket to move along the X / Y direction, and enabling the positions of the ball head and the ball socket to coincide as much as possible in the X / Y direction; running the ball socket run in a Z direction until the ball socket is in contact with the ball socket; andlifting the ball socket along the Z axis from the motion stage through mixed control until the ball head completely enters the ball socket; the positioning unit comprises a servo motor, a ball screw nut, a linear guide rail and a sliding platform. The positioning unit performs force control in the horizontal direction, so that the ball socket can be adaptively close to the ball head, the safety ofthe in-place process is ensured, the assembly stress is reduced, and the operation is simple and quick.

The invention relates to a conductor electrical connection device comprising a contact finger installing sleeve which extends along a left-and-right direction. The contact finger installing sleeve is provided with a plugging hole segment which sleeves the corresponding end part of a plugging conductor under conductive connection in a clearance way. The contact finger installing sleeve is provided with a conductive contact finger structure. The conductive contact finger structure is provided with an elastic contact finger part which stretches to the plugging hole segment in a suspension way and is arranged in a way of inwardly protruding out of the internal hole wall of the plugging hole segment so as to be conductively contacted with the corresponding plugging conductor. The elastic contact finger part can deform in the radial direction of the contact finger installing sleeve under the abutting effect of the plugging conductor so that the radial position of the plugging conductor in the contact finger installing sleeve can be adjusted, effective conductive contact of the electrical connection device and the plugging conductor can be realized through radial deformation of the elastic contact finger part even deviation exists between the original installing position of the plugging conductor and the design position, and thus the assembling accuracy requirement for the plugging conductor can be reduced and the assembling efficiency can be enhanced.

The invention belongs to a storage battery formation process, and specifically relates to an AGM storage battery inner formation process comprises the following steps: firstly, confirming constant-current uninterrupted charging of charging current according to 100% of the actual capacity of a storage battery; then performing standing for 5-25 min when charging for 4-6 min, performing discharging for 1 min and charging 0.9-1.0 storage battery actual capacity, then performing vacuum acid pumping, and finally performing confirmation according to the total charging ampere-hour amount of 15%-17% when charging is carried out for 4-6 min, performing discharging for 1 min and performing the charging ampere-hour amount. The invention further provides an AGM start-stop storage battery. According tothe AGM storage battery inner formation process provided by the invention, the charging acceptance of the polar plate is greatly improved, the formation time is shortened to be within 7-8 hours, and the formation efficiency is improved.

The invention belongs to the field of aero-engine external pipeline design, and particularly relates to a pipeline connecting device with multidirectional displacement compensation capability. The pipeline connecting device comprises a first pipeline, wherein one end of the first pipeline is a columnar port, the outer wall is an outer cylindrical surface, and the tail end protrudes to form a flange; a second pipeline, wherein one end of the second pipeline is a spherical port; and a connecting pipe which comprises a first sleeve opening and a second sleeve opening, wherein the first sleeve opening sleeves the first pipeline, an elastic O-shaped ring is arranged between the first sleeve opening and the outer cylindrical surface, the second sleeve opening sleeves the second pipeline, the position, corresponding to the spherical port of the second pipeline, of the second sleeve opening is in a horn shape, and a first connecting piece and the connecting pipe are matched in shape to clamp the elastic O- shaped ring. Through the integrated design of axial compensation and angular compensation, the compensation requirements of the pipeline in all directions can be met while the sealing performance is guaranteed; and the pipeline connecting device has the advantages of a simple structure, small occupied space and strong compensation capability.

The invention relates to a rigid-flexible combined I / O modular device, comprising: a rigid-flexible combined I / O module assembly and a box assembly; and the rigid-flexible combined I / O module assemblycomprises: a panel, an I / O port backboard assembly, an adapter board assembly, and a motherboard assembly connected to the lower end of the adapter board assembly in sequence, wherein a connection board between the adapter board assembly and the motherboard assembly is a flexible connection board. The rigid-flexible combined I / O modular device provided by the present invention achieves communication between the adapter board assembly and the motherboard assembly through the flexible connection board, thereby improving the assembly processability, realizing modular and high-reliability connection, and improving system reliability, signal integrity, and device electromagnetic compatibility.

The invention discloses an array type pressure measuring device, and the device comprises a piezoresistive sensitive chip which is used for applying a reference pressure to the front surface of the piezoresistive sensitive chip and applying an external gas pressure to the back surface of the piezoresistive sensitive chip to generate a pressure difference; a circuit system used for converting the generated pressure difference into an electric signal which is in direct proportion to pressure change, outputting the electric signal and performing processing and calculating; and an air path system used for providing air pressure and acting on the two surfaces of the piezoresistive sensitive chip so as to generate the pressure difference. According to the device, the alloy substrate and the piezoresistive sensitive chip are directly bonded through the packaging sealant, and the PCBs are located on the two sides of the piezoresistive sensitive chip to be electrically connected, so that the assembly stress can be reduced, support is provided for precise control over the stress and temperature state of the piezoresistive sensitive chip, and the piezoresistive sensitive chip or related circuit system components are convenient to disassemble and independently replace; and multiple layers of circuit chips are stacked and integrated, and an internal integrated gas circuit system is beneficial to miniaturization of the whole pressure measuring device assembly.

The invention discloses a method for controlling a bulging deformation of a valve-regulated lead-acid (VRLA) storage battery. The method comprises a process of assembling a plate group in a jar, a process of performing capping, a process of adding an electrolyte into a battery, a process of forming the battery and a process of buckling a safety valve. In the process of assembling the plate group in the jar, a plate group assembling compression ratio is controlled between 20 percent and 25 percent. The process of adding the electrolyte into the battery comprises the following steps: firstly, performing cryogenic refrigeration on the battery; putting the assembled battery into an environment being lower than 0 DEG C in temperature, and standing the battery for 4-15 hours; and taking the refrigerated battery out, and adding the electrolyte immediately, wherein the temperature of the electrolyte is controlled below 15 DEG C. In the process of forming the battery, a water bath temperature is controlled between 20 DEG C and 30 DEG C. Compared with a battery produced with an existing process, the VRLA storage battery manufactured with the method has the advantages that a bulging deformation situation is improved remarkably; the bulging deformation of the VRLA battery is eliminated or reduced greatly; a deformation amount can be controlled below 1mm; and tremendous economic losses of enterprises due to return of deformed batteries are avoided.

The invention is an axial support mechanism for the main mirror of a vehicle-mounted adaptive optical imaging telescope, which belongs to the field of large-aperture adaptive optical imaging detection, and solves the technical problems of low natural frequency and low overall rigidity in the prior art; the invention includes balance Mechanism, main mirror and main mirror room; the balance mechanism includes a balance assembly and a balance lever; the two ends of the balance lever are respectively fixedly connected to a balance assembly, and a plurality of balance mechanisms are uniformly distributed and fixedly connected to the main body through the column hinge assembly and the balance lever. In the mirror room, the main mirror is on a plurality of balance mechanisms; the invention has compact structure, good system rigidity, high utilization of structural space; small assembly stress, little influence on the surface shape of the main mirror, and high positioning accuracy.

The invention discloses an optical axis angle adjustment and calibration method, which belongs to the technical field of precision optical machine assembly and calibration, and relates to an optical axis adjustment and calibration method. The optical axis angle adjustment and calibration method comprises the steps of: adjusting azimuth and pitch angles of an infrared target source 1 to enable an optical axis of the infrared target source 1 to be parallel to an infrared assembly 2; detecting azimuth angle deviation alpha and pitch angle deviation beta of an optical axis of a laser receiving assembly 3; and calculating thicknesses of three gaskets according to a formula. By adopting the innovative optical axis angle adjustment and calibration method, the thickness of each gasket is preciselycalculated according to the test result of the optical axis deviation, and precise assembly and calibration of the optical axis are achieved. The optical axis angle adjustment and calibration methodis high in precision, high in efficiency and stable in optical axis.

The invention belongs to the field of gas turbine engines of aviation, ships, ground gas turbines and the like, and particularly relates to a gas turbine engine component thermal state performance test protection device. The device comprises a first mounting edge, a distance fixing rod, an elastic channel and a second mounting edge. According to the invention, a fixed-distance compensation mode isadopted to replace an existing gas turbine engine component thermal state performance test design structure, so that it is guaranteed that gas turbine engine components are not damaged, and the testcost is reduced. In addition, by the adoption of the technical scheme, the gas turbine engine test component directly uses an engine installation part, so that the number of processed test pieces is reduced, the test cost is reduced, the real working state of the test component is simulated, and the test data accuracy is improved.

The invention discloses a method for stress monitoring of an aircraft assembly process based on appearance detection. The method comprises the following steps of hoisting a component A and a componentB into places; establishing an aircraft coordinate system and measuring appearance key points of the component A and the component B respectively, recording coordinate records of the appearance key points after posture adjustment of the component A and the component B to an initial data storage unit and transmitting to a data operation unit; pre-aligning the component A and the component B; carrying out trail assembly on a transition section framework and skin, monitoring process positions of the appearance key points by using a measuring instrument, and sending the process positions to the data operation unit; comparing location degree of the appearance key points through the data operation unit, if the change exceeds a preset threshold value, giving out an alarm, and otherwise installing the transition section framework and the skin. According to the method, the transition section framework is installed under a condition of monitoring the coordinate condition of the appearance key points, so that the deformation of the parts at a docking part due to the assembly stress generated by forced assembly is avoided, the assembly quality is improved, the service life of the aircraft isprolonged, and the assembly stress of the docking process of the aircraft is reduced.

The invention discloses a light sensation imaging assembly of a camera. Based on the invention, the imaging module can only be directly and fixedly connected with the lens module, and can be indirectly arranged on the fixed frame through the mounting housing assembled with the lens module, so that the assembly stress borne by the circuit board of the imaging module can be reduced; therefore, the influence of deformation or vibration of the circuit board in response to the assembly stress on the image sensor of the imaging module is reduced, so that the influence of the assembly stress on the imaging quality of the imaging module is reduced.

The invention provides an oil suction pipe part, comprising a pipeline flange, an oil suction bent pipe, a fixing frame and an oil suction cover. The front end of the oil suction bent pipe and the oilsuction cover are solidified, the tail end of the oil suction bent pipe and the pipeline flange are solidified, and the fixing frame is arranged at the tail end of the oil suction bent pipe; and theoil suction cover comprises an arc-shaped upper cover, an arc-shaped lower cover and an arc-shaped filter net, the arc-shaped upper cover and the front end of the oil suction bent pipe communicate andare solidified, the arc-shaped upper cover and the arc-shaped lower cover are in clamping fit and solidified, the arc-shaped filter net is arranged between the arc-shaped upper cover and the arc-shaped lower cover, and an oil suction opening is further formed in the arc-shaped lower cover. According to the oil suction pipe part provided by the invention, an assembly-type oil suction pipe part isadopted as the fixing frame so that the assembly error within a certain range can be eliminated, assembly stress is reduced, reliability is improved, and a breakage failure caused by long-term usage is avoided.

The invention discloses a bidirectional-positioning small-stress assembly structure. The bidirectional-positioning small-stress assembly structure comprises a shaft and a shaft sleeve, wherein a fit part of the shaft and the shaft sleeve is positioned between a retaining step and a positioning step at the two ends; and the shaft and the shaft sleeve are in noncircular-curve interference magnitude fit, for example standard elliptical-curve interference magnitude fit. The assembly interference magnitude of the shaft and the shaft sleeve accounts for 0.02%-0.03% of an assembly diameter; a retaining groove and a positioning groove are formed in the shaft sleeve respectively; the retaining groove and the positioning groove are fitted with the retaining step and the positioning step respectively; the diameter of the retaining step is 1.0025 times that of the assembly diameter (a long shaft); the assembly interference magnitude between the retaining step and the retaining groove is 0.02%-0.03%; and the length of the retaining step accounts for 10% of the shaft sleeve fit length, and the length of the retaining groove is 1.04 times that of the retaining step. The bidirectional-positioning small-stress assembly structure can be positioned in a bidirectional mode to prevent the shaft and the sleeve from relative axial movement; moreover, the assembly stress is small, the shearing stress is gentle, and relative sliding between the shaft and the sleeve is avoided; and the reliability and the stability of operation after assembly are greatly improved.