84results about How to "Expand the scope of safe work" patented technology

The invention discloses a leveling control method and system for a fire engine. According to the method and the system, a force leveling control strategy is introduced after angle leveling when supporting pieces of the fire engine are automatically unfolded, angle leveling is adopted as rough leveling means, and force leveling is adopted as fine leveling means, so that the angle leveling of the whole fire engine is sensuously implemented, supporting force is more balanced to prevent a certain support leg from leaving from the ground or leaves from the ground by a height exceeding the limit (the standard forbids excess of 20mm) in an unfolding process of a cantilever crane, the safe working range of an elevating fire engine is maximally widened, and the working safety and stability of the elevating fire engine are improved.

The invention relates to a radial sleeve type labyrinth type magnetic fluid sealing device. The radial sleeve type labyrinth type magnetic fluid sealing device comprises a shaft, a shell, a left poleshoe ring, a right pole shoe ring, a sleeve and a permanent magnet ring. The left pole shoe ring and the right pole shoe ring are arranged in the shell in a spaced mode; the shaft is sleeved with thesleeve located between the left pole shoe ring and the right pole shoe ring; the permanent magnet ring is arranged in the shell and located between the left pole shoe ring and the right pole shoe ring; a gap is reserved between the outer circular face of the sleeve and the inner circle face of the permanent magnet ring; pole teeth I are arranged on the right end face of the left pole shoe ring atintervals; pole teeth II are arranged on the left end face of the sleeve at intervals, and pole teeth III are arranged on the right end face of the sleeve at intervals; and pole teeth IV are arrangedon the left end face of the right pole shoe ring at intervals. The radial sleeve type labyrinth type magnetic fluid sealing device is used for solving the problem of low pressure-resistant performanceof an existing sealing device, and the sealing technology is successfully applied to the fields such as the high-speed and heavy-load field.

The invention discloses a leveling control method and a leveling control system of a firefighting vehicle. The leveling control method aims to lead into a force leveling control strategy after angle leveling in automatic expansion of a firefighting vehicle supporting member. Angle leveling is used as a coarse leveling facility, and force leveling is used as a fine leveling facility so that the angle leveling of the integral firefighting vehicle is visually realized, and furthermore supporting force balance is realized, thereby preventing certain supporting leg off-ground or off-ground height limit exceeding (wherein the standard height requirement is not larger than 20mm) in an arm bracket expansion process, thereby maximally increasing a safe operation range of hoisting firefighting vehicles, and improving operation safety and stability of the hoisting firefighting vehicles.

The invention relates to the technical field of gas turbines, and particularly discloses a fuel switching device for a multi-fuel combustion chamber of a gas turbine. The fuel switching device comprises a flame tube, a natural gas fuel channel, a synthesis gas fuel channel and a fuel front-end system, wherein the fuel front-end system comprises a natural gas purge system and a synthesis gas purge system; an inlet of the natural gas purge system is connected with a natural gas source; the outlet of the natural gas purge system is connected with the inlet of the natural gas fuel channel; the inlet of the synthesis gas purge system is connected with a medium and low heat value gas source; the outlet of the synthesis gas purge system is connected with the inlet of the synthesis gas fuel pipeline; a natural gas pressure-stabilizing valve is arranged at the upstream of the natural gas purge system; a third control valve is arranged at the downstream of the natural gas purge system; a synthesis gas pressure-stabilizing valve is arranged at the upstream of the synthesis gas purge system; a second control valve is arranged at the downstream of the synthesis gas purge system; and a first control valve is arranged between the downstream of the third control valve and the upstream of the second control valve. According to the fuel switching device, the required effective jet area of the head part of a nozzle when a lot of synthesis gas is jet is effectively reduced.

The invention relates to the technical field of mechanical engineering sealing, and particularly relates to a cone magnetic fluid sealing device. The device comprises an outer pole piece, an inner pole piece, outer permanent magnets and inner permanent magnets, wherein the inner pole piece sleeves a shaft, the outer wall of the inner pole piece is a conical surface, a plurality of annular grooves I are formed in the conical surface at intervals, and pole teeth I are formed between two adjacent annular grooves I; the inner permanent magnets are installed in the annular grooves I; the outer pole piece is installed on the inner wall of a shell, the inner wall of the outer pole piece is a conical surface, the inner wall of the outer pole piece is parallel to the outer wall of the inner pole piece, a plurality of annular grooves II which correspond to the annular grooves I are formed in the inner wall of the outer pole piece, and pole teeth II are formed between two adjacent annular grooves II; the outer permanent magnets are respectively installed in the annular grooves II; the pole teeth I respectively correspond to the pole teeth II, and gaps are formed between the pole teeth I and the pole teeth II. The sealing device has high pressure-resistant capacity, and the problem of poor sealing performance and reliability of an existing large-gap magnetic fluid sealing device is solved.

The invention relates to the field of mechanical engineering sealing, in particular to a magnetofluid sealing device for high vacuum. The magnetofluid sealing device comprises a stepped shaft, a shell, a left pole shoe, a right pole shoe and a permanent magnet ring. The stepped shaft comprises a middle shaft with the maximum diameter and a plurality of sets of secondary shafts with the sequentially reduced diameters. The permanent magnet ring is arranged at the position, corresponding to the outer circle face of the middle shaft, of the inner wall of the shell. The left pole shoe and the rightpole shoe are arranged on the two sides of the permanent magnet ring and are symmetric. The end face and the annular face of the left pole shoe and the end face and the annular face of the right poleshoe correspond to the outer circle faces and the end faces of the middle shaft and the secondary shafts correspondingly. The end face of the middle shaft and the outer circle faces and the end facesof the secondary shafts are each provided with pole teeth which extend in the radial direction or the axial direction, gaps are reserved between the pole teeth and the corresponding end faces and theannular faces of the left pole shoe and the right pole shoe, and the magnetofluid is located in the gaps. By means of the magnetofluid sealing device for high vacuum, the problem that an existing sealing device is relatively low in pressure resistance and other problems can be solved.

The invention relates to a convex step shaft magnetofluid sealing device. The convex step shaft magnetofluid sealing device comprises a shell, a sealing assembly and an end cover. The sealing assemblycomprises a shaft. The shaft is rotationally arranged in the shell through a bearing. The shaft comprises at least one convex step part. The convex step part comprises a plurality of steps sequentially arranged in the axial direction, and the outer walls of the adjacent steps are connected through arc chamfered transition faces. Each transition face is sleeved with a pole shoe matched with the transition face, wherein the pole shoe extends towards one or two sides of the transition face to the position corresponding to the corresponding step on the side portion of the transition face. Gaps are reserved between the inner walls of the pole shoes and the corresponding transition faces and between the inner walls of the pole shoes and the steps. Pole teeth are arranged on the inner walls of the pole shoes and/or the parts, corresponding to the inner walls of the pole shoes, of the shaft. Permanent magnets are arranged between the adjacent pole shoes. The convex step shaft magnetofluid sealing device is high in pressure resisting capability, the secondary pressure bearing capability and the self-repairing capability are high, the pressure resisting capability and the sealing reliability of magnetic fluid seals under the condition of large gaps are high, and the safety work range is wide.

The invention relates to a reciprocating sealing device for hydraulic cylinder magnetic fluid. The reciprocating sealing device for the hydraulic cylinder magnetic fluid comprises a shell, pole shoe rings, permanent magnet rings, non-magnetic conductive rings and magnetic isolation rings. According to the reciprocating sealing device for the hydraulic cylinder magnetic fluid, a magnetic source isprovided through multiple permanent magnets, the non-magnetic conductive rings are arranged in a space formed by pole shoes, the permanent magnets and shafts in an enclosing mode, the non-magnetic conductive rings are provided with pole teeth, therefore, the problem that the pressure resistance of an existing single-magnetic-source magnetic fluid sealing device and an existing multi-magnetic-source magnetic fluid sealing device is low is solved, and meanwhile the problem that the magnetic fluid utilization rate of an existing magnetic fluid sealing device is low is solved.

The invention relates to a sealing device for magnetic source embedded series-parallel type stepped shaft magnetic fluid. According to the sealing device for the magnetic source embedded series-parallel type stepped shaft magnetic fluid, the diameter of a middle shaft of a stepped shaft is the largest, the diameter of a secondary shaft on the left side of the middle shaft sequentially decreases from right to left, and the diameter of a secondary shaft on the right side of the middle shaft is gradually decreased from left to right; and the sealing device comprises a shell, a left pole shoe ring, a right pole shoe ring, a first permanent magnet ring, a second permanent magnet ring, a third permanent magnet ring and a fourth permanent magnet ring. The problem that an existing sealing device is low in pressure resistance can be solved, and meanwhile the assembling is simple, the processing is easy, and the sealing technology is successfully applied to the fields of high-speed heavy load and the like.

The invention relates to a mixed tooth split type magnetofluid seal device. The mixed tooth split type magnetofluid seal device comprises a stepped shaft, a shell, pole shoe rings, a sectioning non-magnetizer ring and permanent magnet rings. The inner wall of the shell is provided with the sectioning non-magnetizer ring. The stepped shaft is arranged in the inner ring face of the sectioning non-magnetizer ring in a sleeved manner. The outer circle faces of the stepped shaft correspond to the inner ring faces of the sectioning non-magnetizer ring. Each of the inner ring faces of the sectioningnon-magnetizer ring is provided with the corresponding pole shoe rings and the corresponding permanent magnet ring making contact with the pole shoe rings. Gaps are reserved between the pole shoe rings and the corresponding outer circle faces of the stepped shaft and between the permanent magnet rings and the corresponding outer circle faces of the stepped shaft. The pole shoe rings are provided with pole teeth, the pole teeth extend towards the outer circle faces or the end face of the stepped shaft in the radial direction, gaps are reserved between the pole teeth and the outer circle faces or the end face of the stepped shaft, and the magnetofluid is arranged in the gaps. The mixed tooth split type magnetofluid seal device can solve the problems that an existing sealing device is low inpressure resisting performance, and magnetism leakage happens to an inner magnetic field of the sealing device.

The invention discloses a stepped shaft type magnetofluid sealing device. The stepped shaft type magnetofluid sealing device comprises a shaft, an outer shell, sealing rings, pole shoes, magnetofluidand permanent magnets. The shaft penetrates the outer shell, extends out of the two ends of the outer shell and comprises a stepped shaft part, wherein the stepped shaft part is located inside the outer shell. The diameter of a middle step of the stepped shaft part is the maximum, and the diameters of steps at the left side and the right side are decreased progressively and sequentially. Every twoadjacent steps are in circular-truncated-cone transition. The stepped shaft part is provided with cylinder side faces and multiple circular-truncated-cone side faces, wherein the cylinder side facesare parallel with the axis of the shaft, and the circular-truncated-cone side faces are symmetrical about the axis. The inner surface of the outer shell is provided with the two or more pole shoes. Each annular permanent magnet is arranged between the corresponding two adjacent pole shoes. Each pole shoe is provided with radial pole teeth and bevel pole teeth, wherein the radial pole teeth protrude toward the cylinder side faces, and the bevel pole teeth protrude toward the circular-truncated-cone side faces. The magnetofluid is arranged between the radial pole teeth and the cylinder side faces as well as between the bevel pole teeth and the circular-truncated-cone side faces. By means of the stepped shaft type magnetofluid sealing device, the sealing capability and pressure endurance capability of the magnetofluid are greatly enhanced; and the problem that existing sealing devices cannot meet the high-sealing-performance requirement under special working conditions such as the high speed and heavy load is solved.

The invention provides a cross-shaped stepped magnetofluid sealing device. The cross-shaped stepped magnetofluid sealing device comprises a stepped shaft, a shell, a left pole shoe, a right pole shoeand a permanent magnet ring. The stepped shaft is arranged in the shell in a sleeved mode. The stepped shaft comprises an intermediate shaft body with the maximum diameter and a plurality of secondaryshaft bodies with the diameters becoming smaller gradually, and the stepped shaft is bilaterally symmetrical with the intermediate radial section of the intermediate shaft body as the boundary. The permanent magnetic ring is arranged at the position, corresponding to the outer circumference surface of the intermediate shaft body, of the inner wall of the shell, and a gap is reserved between the permanent magnet ring and the outer circumferential surface of the intermediate shaft body. The left pole shoe and the right pole shoe are arranged on the two sides of the permanent magnet ring correspondingly and are symmetrical. Cross-shaped pole teeth are arranged at the junctions of the upper outer circumferential surfaces and end faces of the left and right pole shoes and extend towards the outer circumferential surfaces of the secondary shaft bodies and the end faces of the secondary shaft bodies or the end face of the intermediate shaft body correspondingly, gaps are reserved between theouter circumferential surfaces and the end faces, and magnetofluid is located in the gaps. By adoption of the cross-shaped stepped magnetofluid sealing device, sealing can be achieved in special working conditions such as high-speed and heavy-load working conditions.

The invention discloses a power transistor array structure with an electrostatic protection circuit integrated. Embedding of an electrostatic protection circuit formed by an SCR (silicon controlled rectifier) can be realized by partially replacing region sections of a drain region of a first unit structure of a power transistor with a region P+, and a grid electrode of the SCR is not connected with a grid electrode of the first unit structure but connected with a source electrode of the first unit structure. On the premise that performances of a power transistor array are unaffected and the process is unchanged, electrostatic protection capability of the power transistor array can be improved, false triggering accidents of the silicon controlled rectifier can be effectively reduced, and accordingly safety operation range of the power transistor array can be expanded. In addition, a grid gate structure of the SCR is designed to be recessed towards a drain side, and the region P+ is injected to a body region of a source side, so that the false triggering accidents of the silicon controlled rectifier can be further reduced, and the safety operation range of the power transistor array can be further expanded.

The invention relates to the field of mechanical engineering sealing, in particular to a staggered tooth end face type magnetic fluid sealing device. The staggered tooth end face type magnetic fluid sealing device comprises a left pole shoe, a middle pole shoe, a right pole shoe and a permanent magnet. Pole teeth I and annular grooves I are formed in the left end face of the middle pole shoe, and pole teeth II and annular grooves II are formed in the right end face of the middle pole shoe. Pole teeth III and annular grooves III are formed in the right end face of the left pole shoe, and pole teeth IV and annular grooves IV are formed in the left end face of the right pole shoe. The pole teeth I on the middle pole shoe extend into the annular grooves III of the left pole shoe, the pole teeth III of the left pole shoe extend into the annular grooves I of the middle pole shoe, the pole teeth II of the middle pole shoe extend into the annular grooves IV of the right pole shoe, and the pole teeth IV of the right pole shoe extend into the annular grooves II of the middle pole shoe. A step notch is formed in the position, close to an axle, of the left end face of the left pole shoe, and a step notch is formed in the position, close to the axle, of the right end face of the right pole shoe. The permanent magnet is installed in the step notches. The sealing device is good in sealing effect and stable in sealing performance.