318 results about "Radial plane" patented technology

The utility model provides a probe purging device which comprises the components of a device base which is provided with a convex step and a plunger piston which is formed on the lower plane of the convex step; the blowing arm comprises a vertical air pipe which vertically penetrates through the device base and a horizontal air nozzle which is arranged below the device base and is parallel to the surface of the device base, and the vertical air pipe and the horizontal air nozzle are connected to form an L-shaped structure; a shaft hole perpendicular to the rotary limiting handle is formed in one end of the rotary limiting handle, a notch is formed in the outer side of the shaft hole, a groove is formed in the radial plane of the shaft hole on the outer side of the shaft hole in the direction perpendicular to the notch, and the vertical air pipe of the blowing arm perpendicularly penetrates through the device base through the shaft hole of the rotary limiting handle above the device base; the spring is vertically arranged between the upper portion of the device base and the shaft hole of the rotary limiting handle and surrounds the outer side of the vertical air pipe, and the rotary limiting handle controls the vertical air pipe to horizontally rotate and / or vertically move so as to control the horizontal air nozzle to be aligned with the probe for blowing.

A downhole tool, with an elongate tool housing that extends around a central longitudinal tool axis, houses a sting, a press device, and a bending arm. The sting is movable in a radially outward direction. The press device acts on the sting, to force the sting in the radially outward direction upon relative movement of the press device, in longitudinal direction, with respect to the sting whereby the sting may extend outside the tool housing. The sting is mounted on a distal end of the bending arm. At its proximal end the bending arm is longitudinally secured stationary relative to the tool housing. The sting and the distal end of the bending arm are movable in unison in a longitudinal-radial plane from the central longitudinal tool axis. The downhole tool can be used to perforate a wall of a downhole tubular arranged within a borehole in the Earth.

A ring seal includes an annular body defining an axial hole therethrough for fluid passage in an axial direction and having a radial plane that is perpendicular to the axial direction. An axial side of the ring seal includes deformable annular protrusions extending from the annular body in an axial direction to first and second apexes, which are configured to deform upon engagement with a first planar sealing surface and define a trough therebetween to engage a first annular rounded sealing protrusion or ring. So configured, the ring seal can seal two different types of flow components.

The invention discloses coating equipment with an angle-adjustable sample holder, which comprises a main cabin body, a vacuum pump assembly, a floating seat, a flange seat, an umbrella-shaped sample holder, a transmission rod and a first driver, a vacuum cavity is arranged in the main cabin body, and the vacuum pump assembly is communicated with the vacuum cavity; the floating seat is arranged at the upper part of the mounting hole of the main cabin body in a liftable manner, an elastic sealing sleeve is connected between the floating seat and the mounting hole, the flange seat is arranged at the lower side of the floating seat and extends into the vacuum cavity, and the elastic sealing sleeve surrounds the outer side of the flange seat; the umbrella-shaped sample rack comprises a plurality of carrier plates, the plurality of carrier plates are respectively hinged to the lower end of the flange seat, the hinge axes of the carrier plates are parallel to the radial plane of the flange seat, a through hole is formed in the flange seat, and the transmission rod is axially and movably mounted in the through hole; the first driver is in transmission connection with the transmission rod in the axis direction, a plurality of rack parts are arranged at the lower end of the transmission rod, gear parts are arranged at the ends, close to the flange base, of the multiple carrying plates, and the rack parts are meshed with the gear parts.

An off-road vehicle includes an intake duct and an air cleaner. The intake duct defines a clean conduit. The air cleaner is connected to the intake duct, and includes an air cleaner case and an air cleaner element. The air cleaner case defines an internal space of the air cleaner. The air cleaner element divides the internal space into dirty and clean regions. The air cleaner case includes an intake port, an exhaust port, and a cylinder. The intake port faces the dirty region. The exhaust port faces the clean region and communicates with the clean conduit. The cylinder protrudes diagonally upward and toward the internal space. The cylinder has a protrusion end portion that is inclined relative to an imaginary radial plane in an angle direction from the plane toward an imaginary vertical plane. The imaginary radial plane is orthogonal to an axis of the cylinder.

Abrasive articles include a circular center member having an outer edge, a radial line, and a radial plane, a plurality of bristles extending outward from the outer edge of the circular center member and having a projection on the radial plane of the center member, the bristles comprise a plurality of abrasive particles, at least a portion of the bristles orient with the projection at a slant angle relative to the corresponding radial line. The abrasive article can have a first direction of use and a second direction of use opposite to the first direction of use, and the abrading performance achieved by the first and the second directions of use is different from each other. Robotic abrading systems can include such abrasive articles for advantageous operations. Methods of making and using such abrasive articles are also disclosed.

The invention relates to the technical field of optical engines, and discloses a pluggable optical engine packaging structure, which comprises a substrate, a silicon optical chip, an optical fiber array unit and an upper cover body, and is characterized in that the silicon optical chip is arranged on the substrate; the silicon optical chip is provided with a first coupling part and a positioning seat, and the positioning seat is provided with a light through hole which penetrates up and down and corresponds to the first coupling part. The optical fiber array unit comprises an optical fiber array and a fixing structure, a second coupling part is arranged on the lower side of the fixing structure, and the second coupling part is in light conduction with the optical fiber array; the upper cover body is mounted on the substrate, an insertion hole is formed in the upper cover body corresponding to the positioning seat, and the fixing structure is inserted into the insertion hole in a guiding manner; a first alignment structure is arranged on the upper side of the positioning seat, and a second alignment structure is arranged on the lower side of the fixing structure; the second alignment structure and the first alignment structure are positioned and matched in the radial plane of the light through hole, and the second coupling part and the first coupling part are aligned up and down; an elastic limiting piece is installed in the inserting hole, the fixing structure is provided with a matching part, and the elastic limiting piece and the matching part are axially stopped during locking.

The invention discloses a propeller hub for a helicopter, a rotor system and the helicopter, and relates to the technical field of aircrafts, the propeller hub comprises a variable pitch hinge mounting seat, an inner propeller hub center body, an elastic device and at least three force transmission devices, and the inner propeller hub center body is arranged in an inner cavity of the variable pitch hinge mounting seat; the elastic device is connected with the inner propeller hub center body and the variable pitch hinge mounting seat; each force transmission device is movably connected with the inner propeller hub center body, each force transmission device is connected with the inner side wall of the variable-pitch hinge mounting seat, and the variable-pitch hinge mounting seat can rotate relative to the force transmission devices so as to generate tilting rotation relative to the radial plane of the rotor shaft; when the rotor shaft rotates, the rotor shaft can drive the inner propeller hub center body, the force transmission devices and the pitch-variable hinge mounting base to rotate. And when the variable-pitch hinge mounting seat tilts relative to the radial plane of the rotor shaft, the elastic device can be compressed or stretched, and the variable-pitch hinge mounting seat can be reset under the action of restoring force of the elastic device. Flight flexibility and stability can be ensured, and the flight quality of the helicopter is effectively improved.

The invention provides a floating mechanism for blind plugging connection and a liquid cooling blind plugging connection system. The floating mechanism comprises a mounting fixing seat fixedly connected with a case; the joint mounting seat is used for mounting a blind-plug joint; the floating connecting assembly is connected between the mounting fixing seat and the joint mounting seat and is configured to allow the joint mounting seat to float in a radial plane relative to the mounting fixing seat; the independent guide mechanism is arranged between the mounting fixing seat and the joint mounting seat and is separated from the floating connecting assembly in space; the independent guide mechanism is configured to restrain axial deflection of the connector mounting base when the connector mounting base floats in the radial direction. The blind plug connector is used for solving the problem that an existing blind plug connector cannot meet the dual requirements of compensating macroscopic assembly tolerance and restraining microcosmic angle deflection at the same time in a limited space due to mutual restriction of the floating amount and the deflection control capacity, and consequently plug-in failure is caused.

A ring seal includes an annular body defining an axial hole therethrough for fluid passage in an axial direction and having a radial plane that is perpendicular to the axial direction. An axial side of the ring seal includes deformable annular protrusions extending from the annular body in an axial direction to first and second apexes, which are configured to deform upon engagement with a first planar sealing surface and define a trough therebetween to engage a first annular rounded sealing protrusion or ring. So configured, the ring seal can seal two different types of flow components.

The present invention discloses a wearable reversible shaftless propeller for underwater diving, comprising: a fixed base bracket; and a rim propeller, which is transferred to the fixed base bracket, and the rim propeller has two transfer status positions based on the fixed base bracket, one of which is a reset status position, and the radial plane of the rim propeller in the reset status position is parallel to the plane of the forward direction, and the other is a propulsion status position, and the radial plane of the rim propeller in the propulsion status position has a predetermined angle with the plane of the forward direction; and a body structure, which is internally configured with an electrically connected battery and a control circuit; the battery and the control circuit inside the body structure are electrically connected to the rim propeller. The invention solves the technical problems that the underwater propeller in the prior art is large in size, inconvenient to carry, and generates thrust through a shaft propeller, which will be entangled when encountering foreign objects such as ropes, and the overall functional safety and stability are poor.

The invention relates to a feeding tank and a feeding and preheating system, belongs to the technical field of recycling of recyclable and renewable resources such as household garbage, industrial garbage and biomass, and solves the problems that in the prior art, a feeding system of existing gasification equipment is prone to material blockage and uneven in material preheating, and waste heat of the system cannot be recycled. The feeding tank comprises a material tank body, a heat exchange jacket arranged outside the material tank body, a rotating shaft arranged in the height direction of the material tank body and penetrating through the material tank body, and a material stirring piece arranged in the axial direction of the rotating shaft. The material stirring pieces comprise the outer side material stirring pieces and the inner side material stirring pieces, and the outer side material stirring pieces and the inner side material stirring pieces are sequentially and alternately arranged in the axial direction of the rotating shaft. And the projections of the outer side material stirring sheets and the inner side material stirring sheets on the radial plane of the rotating shaft are not overlapped. And the fluidity and the preheating effect of the material are improved.

Particles are sorted into paths based on a measurable parameter by forming them into a stream in at least one duct carried on a body rotating around an axis where the duct is shaped so that the particles are accelerated to cause the particles separated into the duct to be aligned one after another in a row in the duct. The parameter of the particles are measured in the aligned stream one after the other and the particles are directed into one of a plurality of paths as determined by the measurement. In one arrangement the body comprises a disk member having a front face facing a supply conduit and the duct lies in a radial plane of the disk member. In one arrangement the measurement of the parameter is carried out by one or more measurement devices either carried on the disk or outside the edge of the disk.

This invention provides a high-efficiency integrated wastewater treatment device, including a flocculation unit. The flocculation unit includes a drive component, a transmission shaft, a dosing container, and an impeller assembly. The drive component is connected to the transmission shaft; the dosing container communicates with the inner cavity of the transmission shaft; the transmission shaft has several dispensing holes; the impeller assembly includes a lower ring and an upper ring coaxially sleeved on the transmission shaft, with the lower and upper rings spaced apart along the axial direction of the transmission shaft; several blade groups are evenly distributed circumferentially between the lower and upper rings; each blade group includes inner and outer blades spaced radially, with the inner and outer blades located in the same radial plane; both the inner and outer blades are plate-like structures with two arc-shaped edges, the arc-shaped edges of the inner blades protruding towards the transmission shaft, and the arc-shaped edges of the outer blades protruding away from the transmission shaft. This invention provides a high-efficiency integrated wastewater treatment device that effectively improves the flocculation effect of the entire space, creating conditions for efficient sedimentation.

An element for a counter-rotating twin screw processor having a pair of screw shafts is disclosed. The element comprises an axial bore for mounting on a screw shaft. The element further comprises multiple lobes and defines a first outer diameter (FOD), a second outer diameter (SOD), a first inner diameter (FID) and a second inner diameter (SID). The FOD is larger than the SOD, the FID is larger than the SID, and a radial center distance ‘a’ between the screw shafts is defined by (FOD+SID) / 2. At least one lobe has a cross sectional profile in the radial plane defining a first segment extending from the FOD to the FID and a second segment extending from the FOD to the SID, or the first segment extending from the SOD to the FID and the second segment extending from the SOD to the SID.

To improve total performance of high mileage, high speed durability, and steering stability.SOLUTION: This tire comprises: a carcass including a carcass code; a belt including a belt code and provided outside the carcass in a tire radial direction; a band including a band code and provided outside the belt in the tire radial direction; and a tread provided outside the band in the tire radial direction. The band code contains a polyethylene terephthalate fiber. When the tread is seen in the tire radial direction in a plan view, an intersection angle which is smaller one of angles between a tire circumferential direction and the longitudinal direction of the belt code is 0-25 degrees. The belt code includes four or more filaments. A radio (Dba / Dbr) of a band code diameter Dba (mm) to a belt code diameter Dbr (mm) satisfies the following expression: 0.5<Dba / Dbr<1.8 (Expression 1).SELECTED DRAWING: Figure 1

The invention discloses automatic welding equipment for an inner circular seam of a large-diameter steel pipe and an automatic welding method for the inner circular seam. The automatic welding equipment comprises an equipment main machine, a welding working device and a connecting device, and a walking mechanism is arranged on the equipment main machine and / or the welding working device; the connecting device comprises a first connecting plate connected with the equipment main machine, a second connecting plate connected with the welding working device and a deviation mechanism used for connecting the first connecting plate and the second connecting plate and enabling the second connecting plate to deviate relative to the radial plane of the steel pipe, and a first positioning mechanism is arranged on the equipment main machine. A second positioning mechanism is arranged on the welding working device; the deviation function of the connecting mechanism can achieve vibration reduction, the situation that the work and operation of a welding working device are affected by vibration of an equipment host is avoided, and therefore the welding quality is guaranteed, and walking and positioning are suitable for the conditions that the axes of two steel pipes are not coincident, and the straightness and roundness of the steel pipes do not reach the standard. Therefore, the automatic welding equipment for the inner circular seam of the large-diameter steel pipe can still complete automatic welding.

The utility model relates to the field of fuel cell hydrogen circulating pumps, in particular to a blade of a vortex type pump impeller. Comprising an impeller, a plurality of arc-shaped blades are uniformly arranged on the outer side of the impeller along the circumference, each arc-shaped blade comprises a top surface, a working surface, a back surface and a side wall between the working surface and the back surface, the working surface is a concave surface, the back surface is a convex surface, and the side wall is a partial cylindrical surface parallel to the radius of the impeller. The side wall extending in the radius direction of the impeller and the working face formed by the concave face conform to the distribution rule of the relative speed of media in an impeller runner, the working face is large, and formation and development of vortex flow are facilitated. The back surfaces of the blades are convex surfaces, so that flow separation around the blades can be reduced. The radius of the cylindrical surface of the side wall does not exceed one fourth of the maximum thickness of the blade, energy loss of media near the edge of the blade can be reduced on the premise of ensuring the strength of the blade, the speed component of the media on the radial plane of the impeller is increased, and the pressure rise and efficiency of the vortex pump are improved.

The invention discloses a double-impeller centrifugal fan with noise reduction type centrifugal impellers, which belongs to the technical field of cooling fans and comprises a frame, a motor and impellers. An air inlet duct is arranged at the end of the rack, and an air outlet duct is arranged on the side wall of the rack. The impeller comprises a rear wheel disc, a front wheel disc and a plurality of blades, the blades are clamped between the rear wheel disc and the front wheel disc in an arc-shaped plate shape, the blades are rotationally and symmetrically arranged on the radial plane of the impeller in the circumferential direction, and an air inlet of the front wheel disc is opposite to the air inlet channel. The cutting angles of the air outlet ends and the air inlet ends of the blades are controlled within a certain angle range, and the noise influence is reduced while it is ensured that the blades have high air exhaust efficiency. The beveling design of the air outlet cutting edge and the air inlet cutting edge of the blade can improve the phenomenon of non-uniform airflow at the turning position, so that the circumferential speed of the airflow on different sections of the blade is changed, and the airflow at the front edge of the blade enters an impeller runner without impact as much as possible.

A centrifugal pump for conveying a fluid, includes a pump housing, a rotor configured to convey the fluid disposed within the housing; and a stator which, together with the rotor, forms an electromagnetic rotary drive configured to rotate the rotor about an axial direction. The stator is a bearing and drive stator with which the rotor capable of being magnetically driven without contact and magnetically levitated without contact with respect to the stator. The rotor is passively magnetically levitated in the axial direction, and actively magnetically levitated in a radial plane perpendicular to the axial direction. The pump housing includes comprising a bottom and a cover, and the rotor is arranged in the pump housing between the bottom and the cover with respect to the axial direction. An indentation is disposed in the bottom or in the cover, the indentation being configured to generate a local turbulence.

The application relates to a main shaft fault identification method for a wind driven generator under a variable load operation state, and the method comprises the following steps: acquiring and storing at least two equal-angle interval sampling vibration signals in orthogonal directions in the radial plane of the front and rear rolling bearings of the main shaft and corresponding rotating speed signals; judging whether the storage amount of the equal-angle interval sampling vibration signals reaches a preset storage amount, if the judgment is yes, performing order spectrum calculation on the equal-angle interval sampling vibration signals, and extracting a fault feature vector; judging whether to trigger main shaft fault diagnosis according to a real-time vibration effective value, if the judgment is yes, inputting the fault feature vector into a pre-constructed confidence rule base model, obtaining the confidence degree distribution of each fault state through confidence reasoning, and identifying the unbalance and misalignment faults of the main shaft of the wind driven generator according to the confidence degree distribution. Compared with the prior art, the application can accurately extract non-stationary fault features under the variable load operation state of the wind driven generator, and improves the accuracy and reliability of fault diagnosis.

Circuit breaker and pressurized fluid handling system comprising such a circuit breaker. In the coupled configuration of the male (100) and female (200) elements of the circuit breaker (10), the first and second radial passages (126, 226) are in fluidic communication, and proximal (132) and distal (134) seals are arranged on either side of the radial passages. A first valve (110) comprises a distal stem (110C) sliding within a male body (102). In an intermediate coupling position, the proximal and distal seals are arranged on either side of the radial passages. The proximal and distal seals are received respectively in a proximal external peripheral groove (136) and in a distal external peripheral groove (138) of the male body (102).A first longitudinal distance (d138), measured between the distal external peripheral groove and a median radial plane (P126) of the first radial passage, is strictly greater than a second longitudinal distance (d136), measured between the proximal external peripheral groove and the median radial plane. Figure for the abstract: 1.

The present invention provides a fuel atomizing nozzle (1) for handling at least two fuels and an atomizing fluid, the fuel atomizing nozzle (1) comprising a solid body (10) having a mainly cylindrical shape around a longitudinal axis (X) defining a first end (11), a second end (12) and a contour surface (16) extending there between connecting the two ends (11, 12), wherein the first end (11) comprises at least one outlet (17), wherein the fuel atomizing nozzle (1) further comprises a fluid compartment (14) being arranged centrally around the longitudinal axis (X) in the solid body (10), at least a first and a second fuel compartment (15a, 15b) being arranged in a radial plane between the fluid compartment (14) and the contour surface (16), the fuel compartments (15a, 15b) having an annular shape, the at least first and second fuel compartments (15a, 15b) being connected to a pre-filling chamber (35) by at least a first and a second fuel channel (25a, 25b), respectively, at least one mixing chamber (40) being arranged between the fluid compartment (14) and the at least one outlet (17), and a fluid channel (24) connecting the at least one mixing chamber (40) and the fluid compartment (14), wherein the pre-filling chamber (35) has an annular shape, and the pre-filling chamber (35) is connected via a pre-filling channel (45) to the at least one mixing chamber (40).

The invention provides a cable protection pipe detection device, method and equipment and a storage medium. A fixing mechanism, a driving mechanism, a laser generator, a laser receiver and a calculation module are integrated. The fixing mechanism is provided with a circumferential fastening support leg for driving the fixing mechanism to stretch; the laser transmitter and the laser receiver are arranged on two sides of the fastening mechanism in a distance-adjustable mode and located in two ends of the pipe, and the receiver moves in a radial plane to receive laser. The system records the laser transmitting and receiving time and the moving angle and distance of the receiver, the calculation module accurately calculates the pipe diameter, the outer diameter and the shape change accordingly, internal tiny damage is accurately captured, and the detection precision and efficiency are remarkably improved.

This invention relates to the field of one-way valve technology, specifically to a low-opening-pressure ultrapure one-way valve, comprising a valve body, a first connecting sleeve, a second connecting sleeve, and further including a valve sleeve, a return spring, a drive assembly, a limit slider, a valve seat assembly, and a tension spring. The valve sleeve is connected to the valve body. Sealing rings are provided on the outer periphery of both the valve body and the valve sleeve. Threaded rings are integrally formed on both the end of the valve body and the end of the valve sleeve. An adjustment groove is provided on the inner periphery of the valve body, and a sliding groove extending to the inner side of the valve sleeve is provided inside the valve body. This invention solves the problem of one-way valves using ordinary thinner helical springs, where the helical spring undergoes radial twisting after repeated use, resulting in a reduction in the total length of the helical spring and preventing a tight fit between the valve disc and the valve body. This is achieved by setting different elastic coefficients for the front and rear sections of the return spring and designing the outer periphery of the return spring as a radial plane, ensuring that the return spring moves tightly against the inner wall of the valve sleeve after compression.

The utility model provides a damping bearing and a photovoltaic tracking support with an angle self-adaption function, the damping bearing comprises a bearing outer ring and a bearing inner ring, the bearing outer ring is provided with a groove with an annular surface, the groove is provided with an annular key groove, the outer surface of the bearing inner ring is provided with an annular spline, and the annular spline is provided with an annular groove. And the bearing inner ring is matched with the annular key groove through the annular spline and is rotatably matched with the bearing outer ring, so that the bearing inner ring realizes relative movement relative to the bearing outer ring in any radial plane of the damping bearing. According to the utility model, the damping function of the damping bearing and the function of the bearing are split, so that the angle self-adaptive capability is realized while the damping force provided by the damping bearing is reserved. The wedge blocks with the adjustable clamping positions are designed in the circumferential direction of the bearing assembly, so that the installation center of the square tube and the rotation center of the damping bearing have certain eccentricity while clamping is achieved, and normal operation of the support system is guaranteed.

A gap seal for an electric machine having a rotor rotatable about a rotation axis and separated from a stator by an annular gap. The gap seal includes an annular body defining a radial ring and an axial ring joined to the radial ring as a unitary part. The radial ring extending in a radial plane and the axial ring extending in a direction of the rotation axis. The radial ring and the axial ring each define an inner surface, the inner surface of the axial ring is configured and positioned to abut an annular axial peripheral surface of the rotor and provide a sliding seal, and the inner surface of the radial ring is configured and positioned to abut a radial peripheral surface of the stator and provide a static seal, wherein the sliding seal and the static seal cooperate to provide a liquid-tight seal of the annular gap.

A reaming hole machining tool includes a shank that can be mounted on a rotating machine, an axis extending longitudinally along the shank, and a cutting part for performing cutting machining, which includes an end face in the feed direction. From the end face in the feed direction of the tool for reaming holes to the axis of the shank, a cutting part, a leading calibration part, and a calibration part are sequentially arranged. The two axial ends of the leading calibration part are respectively connected to the cutting part and the calibration part. The calibration intersection line formed by the circumferential side wall of the leading calibration part on the radial plane is inclined to the axis, and the included angle is less than 90°. The reaming hole machining tool of the present invention is used to perform reaming machining of holes, especially reaming machining of holes formed in metal materials, reduce or eliminate the feed marks on the hole wall, the hole wall is smooth, the surface roughness reaches below Ra0.5, and it presents a bright and uniform silver-white color.

A device for applying a cosmetic product includes a cup comprising at least one lug; a guide comprising a slot passed through by an associated lug of the cup, the slot comprising an upper edge; a sheath comprising internally a helical groove for receiving the lug of the cup; and the lug (32) having an upper flattened area. The upper edge of the slot is inclined with respect to a radial plane.

Screw drive device for use with an impact wrench, comprising a drive shaft (12, 12a) having a drive end (14) that can be coupled to and driven by the impact wrench, and an insert end (44, 44a) with an annular wall (64, 64a), wherein the annular wall (64, 64a) forms a receiving recess (66, 66a) for receiving a screwdriver head (22, 22a) and the annular wall (64, 64a) has several radial holes (46) and each of the radial holes (46, 48) receives a coupling bearing (50, 50a, 50b) that can clamp the screwdriver head (22, 22a) in a drive position and release the screwdriver head (22, 22a) in a coupling position; a hollow coupling sleeve (16, 16a) having an upper end, a lower end and a central cavity (40) that receives the drive shaft (12, 12a), wherein the central cavity (40) has an upper end with a size defined for the passage of the drive end (14) of the drive shaft (12, 12a) and prevents the insert end (44, 44a) of the drive shaft (12, 12a) from passing through it, wherein the hollow coupling sleeve (16, 16a) has an annular groove (72, 72a, 72b) at the lower end of the central cavity (40), the annular groove (72, 72a, 72b) having a size defined to receive the coupling bearings (50, 50a, 50b) therein when the drive shaft (12, 12a) is in the coupling position, such that the loosen the screwdriver head (22, 22a) at the frustoconical ends (52) of the clutch bearings (50), but leave it in the corresponding radial holes (46, 48); a depth control part (18) surrounding the lower end of the hollow coupling sleeve (16, 16a), the depth control part (18) having a lower section (20) having a passage through which the screwdriver head (22, 22a) can extend; and a spring (58) that biases the drive shaft (12, 12a) in the direction of the drive position; characterized by the fact that: The coupling bearings (50, 50a, 50b) each have a cylindrical body with a frustoconical inner end (52) and a circular outer end (54) and are arranged such that they clamp the screwdriver head (22, 22a) in the drive position and the coupling bearings (50) can move from the coupling position to the drive position, wherein the cylindrical body has a total length “a”, the circular outer end (54) has a length “b” which is 1 / 4a, the cylindrical middle section (56) has a length “c” which is 1 / 2a, the frustoconical inner end (52) has a length “d” which is 1 / 4a, the cylindrical middle section (56) has a diameter of 1a, the frustoconical end forms a flat surface which has a diameter “e” which is 3 / 4a, and the circular outer end (54) has a radius “r” has a value of 1 / 2a, wherein the insertion end (44) of the drive shaft (12) has three radial holes (46),the insert end (44) is spaced apart from each other by 120 degrees on a radial plane of the insert end (44), the insert end (44a) of the drive shaft (12a) having three radial holes (46) arranged on a first radial plane of the receiving end (44a), and three radial holes (48) arranged on a second radial plane of the insert end (44a), the second radial plane being separated from the first radial plane, the hollow coupling sleeve (16a) having a first annular groove (72a) and a second annular groove (72b) for receiving the coupling bearings (50a, 50b) which are held in the radial holes (46, 48) arranged on the first and second radial planes when the screw drive device (10a) is in the coupling position, a locking projection (17) being located on one side of the drive shaft (12, 12a) above the insert end (44, 44a) is arranged to serve the screw drive device (10,10a) to fix in the drive position in the reverse direction in order to remove a tightened screw from a workpiece, wherein at least one locking notch (43) is formed at the upper end of the hollow coupling sleeve (16, 16a) and the locking projection (17) can pass through this to fix the screw drive device (10, 10a) in the drive position in the reverse direction, wherein when the locking projection (17) passes through the locking notch (43) and the hollow coupling sleeve (16, 16a) is rotated far enough, the locking projection (17) is held in the hollow coupling sleeve (16, 16a), wherein an axial slot (24) formed at the upper end of the depth control part (18) makes it possible to exchange the depth control part (18) and replace it with another depth control part of a different depth in order to change the depth of a screw driven into a workpiece,wherein the depth control part (18) has a lower section which is smaller than an upper section of the depth control part (18), and wherein each of the radial holes (46) on the first radial plane is spaced 60 degrees apart from each of the adjacent radial holes (48) on the second radial plane.