A kind of novel screw nut
The utility model relates to the standard piece technical field, specifically a kind of nut.
When the nut of common standard screw thread and screw rod cooperate, the in fact just single face contact of the tooth form of internal and external threads, the big portion of the load during screw-threaded coupling concentrates on the first and second circle screw threads of nut.Under the vibration situation, locking nut commonly used can lose 70% coupling mechanism force.
The purpose of this utility model provides a kind of can the cooperation with standard external and can overcome because of the loosening nut of vibration.
Technical solution of the present utility model is: when pitch P>0.7mm, the tooth root portion of the internal thread of new type nut has one and axis to be the spirality conical surface, the circular arc conical surface of 25 °~35 ° of angles or form the conical surface of two different amount in above-mentioned angle.(standard female tooth root portion is the cylndrical surface with parallel axes.) this novel internal thread can be connected with the outside thread of standard, under the effect of locking load, the crest of standard external produces distortion, and as the conical surface of wedge near novel thread root, it can prevent the motion between screw pair, and makes external vibration disappearance.
When pitch P≤0.7mm, screw thread is a sawtooth pattern, and being equally has one 25 °~35 ° the spiral conical surface.
The utility model shows through vibration test: the coupling mechanism force of standard nut can completely lose, and torque take-up nut commonly used will lose 70% coupling mechanism force, and new type nut can keep coupling mechanism force in entire test.Test also shows, when standard nut connects, have 50%~60% load to concentrate on the screw threads of first and second circles, and the load on the new type nut be evenly distribution, thereby improved the fatigue strength of screw thread.
Below in conjunction with accompanying drawing the present invention is further explained:
Fig. 1 is the tooth form schematic representation of novel screw thread of the embodiment 1.
A) as pitch P>0.7mm.
B) as pitch P≤0.7mm.
Fig. 2 is the connection diagram of standard internal and external threads.
Fig. 3 is the connection diagram of novel screw thread and standard external.
Fig. 4 is the load tdistribution curve of novel internal thread when being connected with standard external respectively with standard female.
Fig. 5 is the tooth form schematic representation of novel screw thread of the embodiment 2.
Fig. 6 is the tooth form schematic representation of novel screw thread of the embodiment 3.
The spirality conical surface of the tooth root portion of the internal thread of new type nut and axis are 30 ° of angles as can be known from Fig. 1, and when pitch P≤0.7mm, screw thread is a sawtooth pattern.The situation that is connected of standard female [1] and outside thread [2] as can be known from Fig. 2.The situation that is connected of novel as can be known from Fig. 3 internal thread [3] and standard external [2].Vertical pivot is the load (%) on the screw thread among Fig. 4, and transverse axis is the circle that is screwed into screw thread successively number, and curve I represents the junction curve of standard nut, screw rod, and curve II represents the junction curve of new type nut and master screw.When the standard inner nut connects as can be known from Fig. 4, have 50%~60% load to concentrate on the screw threads of first and second circles, and the Load distribution on the new type nut is comparatively even, thereby has improved the fatigue strength of screw thread.
Embodiment 2: as can be seen from Figure 5, novel screw thread has one to be 30 ° the circular arc type conical surface with axis in tooth root portion.
Embodiment 3: as can be seen from Figure 6, novel screw thread has the conical surface of two different amount in tooth root portion and axis are 30 ° angle.