Screw drill

[0018] Example 1:

[0019] Such as image 3 As shown, the screw drilling tool is composed of an anti-dropping joint 1, an anti-dropping rod 9, a motor assembly, a transmission shaft assembly and an intermediate connecting part. In order to improve the service life of the gears, the material of the internal gear 10 and the external gear 4 is designed to be solid cemented carbide, but because the hardness of cemented carbide is too high, it can only be processed by wire cutting. In order to facilitate the processing of gears by the wire cutting processing equipment, the internal gear 10 and the external gear 4 are designed as straight-toothed cylindrical gears, so that the tooth profile can be processed by the wire cutting method. In order to prevent damage to other parts of the gear except the tooth profile during wire cutting, the gear is designed such that the outer contour of the external gear 4 except the tooth profile is within the cylindrical surface of the tooth root, and the internal gear 10 is inside the other parts except the tooth profile. The contour is outside the cylindrical surface of the tooth root.

[0020] As the screw drill tool occasionally breaks the shell during the drilling process, which will cause the parts below the fracture to fall into the well, so there is a water cap 11 at the lower end of the internal gear 10, and the upper end of the internal gear 10 and the water cap 11 A groove is formed. The inner diameter of the groove is larger than the diameter of the addendum circle of the internal gear 10. The lower end of the screw 8 other than the output shaft is equipped with a shaft extension 13, and the shaft extension 13 is inserted into the internal gear 10. The shape is a stepped shaft, and the lower end step is embedded in the groove. If the motor is always a twin-screw motor, only one output shaft other than the lower end of the screw 8 is equipped with a shaft extension 13; if the motor is always three or more screw motors, it is necessary to have multiple output shafts other than the lower end of the screw 8 Axis extension 13. The upper end of the internal gear is equipped with an anti-dropping ring, and the inner hole size of the anti-dropping ring is smaller than the outer contour size generated by the lower end of the external gear 4 and the shaft extension 13. If the screw housing is broken, the relative position of the screw axis will not change, so the inner and outer gears will not disengage. Since the upper end of the output shaft 3 is equipped with an anti-dropping rod 9, the upper end of the anti-dropping rod 9 is smaller than the inner hole of the anti-dropping connector 1, so even if the housing below the anti-dropping connector 1 is broken, the parts below the fracture will pass through the connection The integrated transmission shaft, internal and external gears, output shaft 3 and anti-dropping rod 9 are firmly hung on the anti-dropping joint 1 so as to avoid the occurrence of falling accidents.

[0021] When the motor is running, the screw will generate radial force and axial force. The inner hole of the motor housing 2 is in direct contact with the screw to bear the radial force, the axial force of the output shaft 3 is borne by the external gear 4 and the water cap 11 directly, and the screw 8 other than the output shaft passes through the shaft extension 13 at the lower end and the inner The upper end of the gear or the upper end of the water cap directly contacts to bear the axial force.

[0022] Example 2:

[0023] Such as Figure 4 As shown, the screw drill is composed of the anti-drop joint 1, the anti-drop rod 9, the motor assembly, the transmission shaft assembly and the intermediate connecting parts. The axis of the motor assembly and the transmission shaft assembly forms a small angle, the bending point At the internal gear. In order to improve the service life of the gears, the material of the internal gear 15 and the external gear 16 is designed to be solid cemented carbide, but due to the high hardness of the cemented carbide, it can only be processed by wire cutting. In order to facilitate the processing of gears by the wire cutting processing equipment, the internal gear 15 and the external gear 16 are designed as straight-tooth bevel gears, so that the tooth profile can be processed by the wire cutting method. In order to prevent damage to other parts of the gear except the tooth profile during wire cutting, the gear is designed such that the outer contour of the external gear 16 except the tooth profile is within the tooth root conical surface, and the internal gear 15 is inside the other parts except the tooth profile. The contour is outside the tooth root cone.

[0024] Due to the occasional shell fracture accident of the screw drilling tool during the drilling process, which will cause the parts below the fracture to fall into the well, so the lower end of the internal gear 15 is equipped with a water cap 11, an internal gear 15 and a water cap 11 A groove is formed at the upper end. The inner diameter of the groove is larger than the diameter of the addendum circle of the lower end surface of the internal gear 15. The lower end of the screw 8 except for one or more output shafts is equipped with a shaft extension 13, which is inserted into the internal gear 15. The shape of the extension 13 is a stepped shaft, and the lower end step is embedded in the groove. If the motor is always a twin-screw motor, only one output shaft other than the lower end of the screw 8 is equipped with a shaft extension 13; if the motor is always three or more screw motors, it is necessary to have multiple output shafts other than the lower end of the screw 8 Axis extension 13. The lower end of the external gear 16 is equipped with an anti-dropping disk 14 which is embedded in the groove, so that the diameter of the addendum of the internal gear 15 is smaller than the outer contour size formed by the step at the lower end of the shaft extension 13 and the anti-dropping disk 14. If the screw housing is broken, the relative position of the screw axis will not change, so the inner and outer gears will not disengage. Since the upper end of the output shaft 3 is equipped with an anti-dropping rod 9, the upper end of the anti-dropping rod 9 is smaller than the inner hole of the anti-dropping connector 1, so even if the housing below the anti-dropping connector 1 is broken, the parts below the fracture will pass through the connection The integrated transmission shaft, internal and external gears, output shaft 3 and anti-dropping rod 9 are firmly hung on the anti-dropping joint 1 so as to avoid the occurrence of falling accidents.

[0025] When the motor is running, the screw will generate radial force and axial force. The lower end of the motor housing 2 is equipped with a thrust plate 7. The inner hole of the motor housing 2 is in direct contact with the screw to bear the radial force. The step surface of all the screws and the upper end surface of the thrust plate 7 directly contact to form a sliding thrust bearing, and all the axial forces of the screw are borne by the thrust plate.