Cause of standard section connecting bolt looseness

Cause of standard section connecting bolt looseness are:mixed installation team personnel,without training,technical quality is uneven,not according to the requirements of construction lifter specification operation,safety awareness is weak;For the provincial process,using the hoisting machinery auxiliary conjoined assembled parts installed,or the standard section on the surface of the assembled integral hoisting,after inspection on connection bolt without fastening;Hand after temporary fixed screw bolt acmotor2.blogspot.com tightening,no longer bolt not use gaskets;Fastening bolt tool is simple,did not use professional torque wrench,short of bolt fastening value;Helped wall after completing the first nut bolts,and the scene the cap number is not enough,back cap missing or not tighten. Helped wall bolt hole is too big,did not use more than electric motor cooling fan 100 x 100 mm 60 mm thick steel gasket;Use of ordinary bolt temporarily use does not change in time. Helped wall bolts are mostly use double-headed screw,and no marked strength,use length,double nut can't tighten;Non-standard professional unit self-check,the acceptance is not serious;Daily use do not timely check and tighten,repair,maintenance,lead to loose bolts,etc.

Second,the elevator installation specification requirements Construction lifter standard section is the spine of the elevator,carrying the weight of the machine itself and cargo movement,the hoisting cage depends on the post up and down reciprocating wheel attachment for standard section,so ac motor electric 65kw attached wheel interface connection,enables the wheel to balance force. Wheel and rack and the place such as transmission mechanism of gear meshing size have the higher requirement of its technology,make sure that the standard section pillar tube joint fault status difference,respectively,0.5 mm and 0.3 mm or less,or less at the same time,the adjacent two rack joint along the direction of tooth difference of 0.3 mm or less,along the length of the tooth difference should be 0.6 mm or less.On the standard section of guide rail and rack column for the first time after installation bolt screw die or have a rivet head. Standard section permanent magnet motors for sale function and requirements of each production manufacturer and requiring less random text file,standard and theory of standard section is not detailed,the expression of the usual safety education,safety inspection and technical clarificaiton,less to this requirement. 

Installation and removal of personnel the subconscious thought standard section strong deformation can not easily,but there is no detailed check for standard section of the wall thickness,therefore in the standard section conjoined assembled parts assembly neglected the connecting bolt fastening.Elevator in the process of installation standard section,section of up to 9 meters high adhesion after installation,the installation of the standard section with conjoined assembled parts are,bolt pseudo screw fixation can be buried. Hanging basket load up and down reciprocating motion acceleration is loose easily guide system two guide verticality and guide the error of the centerline of the overlap is greater than 2 mm,influenced by and other forces,at this time would be a counter weight to run a block or thrown,rope,wire rope guide wheel clearance of large and small. Actuator motor after repair,the rotation speed mismatch cause the vibration of hoisting cage and noise increases,hysteresis shouldn't run into events. Elevator conjoined assembled parts installation operation standard section,to the frequent work of elevator running buried the curse. To resolutely put an end to this is not in conformity with the specification requirements of the installation operation,to regulate the behavior of equipment installation and use.

Induction motor drive system

Asynchronous motor is characterized by simple structure,strong and durable,low cost,reliable operation,low torque ripple,low noise,do not need to position sensor,high speed limit.Induction motor vector control speed regulation technology is mature,the asynchronous motor drive system has obvious advantages,so the earlier was applied in electric vehicle drive system,the current is three phase induction motor still the mainstream of the electric vehicle drive system products,but have been other new type of brushless permanent magnet traction motor driving system is gradually replaced.Biggest disadvantage is that driver circuit is complex,high cost;Relatively permanent magnet motor,induction motor efficiency and power density is low.

2.The brushless permanent magnet synchronous motor drive system Brushless permanent magnet synchronous motor can use cylindrical radial magnetic field structure or disc axial magnetic field structure,due to the power density and high efficiency and magnet prices wide speed range,development prospect is very broad,is a strong competitor in the traction motor of electric vehicle,had been used in a variety of electric vehicles at home and abroad.Built-in permanent magnet synchronous motor,also known as hybrid permanent magnet reluctance motor.The motor on the www.dongfeng-motor.com basis of the permanent magnet torque superposition of the magnetic resistance torque,the existence of the magnetic resistance torque to improve motor overload capacity and power density,and easy to weak magnetic speed regulating,expanding the scope of the constant power operation.Built-in permanent magnet synchronous motor drive system design theory is increasingly perfect and further,with flexible structure,design degrees of freedom,is expected to get high performance,suitable for electric cars,high efficiency,high density and wide speed traction drive.

These cause the attention of the peers in the major car companies,especially the Japanese car company colleague's favor.At present,the American car companies peers in new model design mainly USES the built-in permanent magnet synchronous motor.generator stator Surface;also called permanent magnet

torque motor type permanent magnet synchronous motor,against the built-in permanent magnet

synchronous motor,its weak magnetic speed range is small,low power density.The structure of the motor dynamic response is fast,and is expected to get low torque ripple,suitable for used in automobile electronic servo drive,such as automotive electronic power steering servo motor.Sensorless permanent magnet synchronous motor drive system is currently a hot topic in the research of permanent magnet synchronous motor drive system,will become the development trend of the permanent magnet synchronous motor drive system is one of the potential competitive advantage.Permanent magnet synchronous motor drive system often adopts vector control at low speed,high speed with weak magnetic control.