CN100398872C - rolling screw - Google Patents

Abstract

The invention relates to a rolling screw, the thread of the screw and the nut is the configuration of the thread groove-the crest, its characteristic is: two rows of rolling bodies roll in the tooth socket of the single thread, one row is in a load state, and the other row is in a backflow state. The backflow unit is arranged on the nut, so that the rolling bodies in the single tooth socket can directly rotate in a U shape to complete backflow. Therefore, the rolling body of the invention does not need to have high displacement when reflowing, namely the rolling body can complete reflowing without crossing the crest height of the screw thread, and the invention has the advantages of less turning points, can achieve the purpose of stable rolling of the rolling body and avoids the running disturbance or uncertain motion mode of the rolling body.

Description

rolling screw

technical field

The invention relates to a rolling screw, which is mainly the backflow method of the rolling screw. The backflow method enables the rolling body in the nut of the screw to turn to the backflow to complete circular rolling, so that the screw and the nut move with each other to transmit power.

Background technique

Generally, the rolling element backflow method of the screw can be roughly divided into the outer circulation backflow method, the inner circulation backflow method and the end plug backflow method. Backflow for infinite circulation; the internal circulation backflow method is usually to install an S-shaped path steering unit on the thread of the inner diameter of the nut to connect the two adjacent threads, so that the rolling elements can complete the backflow for infinite circulation. The end plug return method is to set an L-shaped turning path connecting the thread and the return hole on the end surface of the nut, and guide the rolling body to turn to enter the return hole to complete the return cycle. The rolling elements of these three reflow methods all need to cross the crest height of the screw thread teeth, so that the rolling elements reflow at a position higher than the crest of the screw thread, so there is a displacement difference between the height of the rolling position of the rolling element and the height of the reflow position, and they are not at the same height The backflow is completed, and it is easy to cause the rolling elements to twist during the backflow, so that the rolling elements do not run smoothly.

Furthermore, the design of the screw rolling elements can also be divided into the design of single-alveolar single-row rolling and the design of single-alveolar multi-row rolling, but the return method still uses the above-mentioned general rolling-element return method. The design of the alveolar single-row rolling, while US5535638 is the design of single-alveolar multi-row rolling, both of which use the external circulation backflow method, the rolling elements of this backflow method enter the tube body and leave its rolling position, and move up the tube body to The outside of the nut guides back to the rolling position to complete the backflow action. Therefore, the two designs of the rolling elements are also likely to cause the rolling elements to twist during the backflow, making the rolling elements not running smoothly.

Combining the above traditional return methods: when the rolling elements reach the end of the rolling path, the rolling elements are guided away from the end of the rolling path by the return device, so that the rolling elements are guided back to the head end of the rolling path after passing through the return path for rolling. The torsion of the rolling elements is very likely to occur when the rolling elements leave and enter the rolling path.

The rolling elements of the present invention do not require height displacement during reflow, that is, the rolling elements can complete the reflux without crossing the crest height of the thread of the screw thread, and have the advantage of fewer turning points, which can achieve stable rolling of the rolling elements and avoid disturbances in the operation of the rolling elements or indeterminate movement patterns.

Contents of the invention

The present invention proposes a different reflux design based on the study of the reflux design of the rolling elements applied to the rolling screw. This reflux design features: the rolling elements do not need to have a high displacement during the reflux, that is, the rolling elements do not need to cross the thread teeth of the screw. The backflow can be completed at the height of the crest, and the advantages of fewer turning points can achieve stable rolling of the rolling elements, and avoid rolling element running disturbances or uncertain motion patterns.

First of all, the present invention designs the rolling body at a position equidistant from the center of the rotating shaft to complete load rolling and backflow rolling. All are designed in the thread teeth. Therefore, there are two rows of rolling elements rolling in the tooth socket of a single thread, one row is in the state of load, and the other row is in the state of backflow.

Secondly, in order to separate the two rows of rolling elements with different rolling states from each other, the corresponding relationship between the thread teeth of the screw and the nut is changed, and the traditional screw is changed from the crest-crest and alveolar-alveolar configuration to crest. -Alveolar and alveolar-crest configuration, that is, the crest of the screw is placed in the alveolar of the nut, and oppositely, the alveolar of the screw accommodates the crest of the nut; the rolling element is arranged on the screw and The nut corresponds to the crest-alveolar configuration of the thread teeth, so that the two rows of rolling elements in a single alveolar can move in different directions without affecting each other.

Furthermore, in order to connect the rolling paths of the two rows of rolling elements in a single tooth groove into a complete continuous circulation path, a recirculation unit is provided on the nut, which straddles the two adjacent thread tooth grooves of the nut, The return unit also has a turning path to connect the rolling paths of the two rows of rolling elements in the single tooth groove of the screw, so that the two rows of rolling elements can complete the return circulation movement in the single tooth groove of the screw.

In addition, the turning path of the return unit of the present invention can be designed as a symmetrical planar turning path, and the simplest symmetrical turning path is a U-shaped path, so that the rolling elements in a single tooth socket can directly make a U-shaped turning to complete the backflow. In addition, the return path design of the present invention is applicable to both spherical rolling elements (ie, balls) and cylindrical rolling elements (ie, rollers).

In order to facilitate a further understanding of the features and technical content of the present invention, please refer to the following embodiments of the present invention in detail. However, the embodiments and drawings are for illustration and reference purposes only, and are not intended to limit the present invention.

Description of drawings

Fig. 1 is the exploded schematic diagram of screw rod and nut of the present invention

Fig. 2 is a schematic diagram of the rolling path of the rolling body on the screw of the present invention

Fig. 3 is a schematic cross-sectional view of a nut of the present invention

Figure 4 is a detailed view of the reflow unit in Figure 1

Fig. 5 is a schematic diagram of cooperation between screw and nut thread teeth and rolling elements of the present invention

Figure 6 is a schematic diagram of another embodiment of Figure 5

Figure 7 is a detailed view of the rolling element in Figure 6

Explanation of main component symbols

10 screw 11 thread teeth

111 tooth crest 112 tooth alveolar

20 nuts 21 thread teeth

211 tooth crest 212 tooth alveolar

22 return holes 30 return units

31 Rotary path 32 Auxiliary blocks

33 block 40 rolling body

41 rolling body 42 rolling body

α inclination angle D _i inner diameter

ψ _o major diameter ψ _i minor diameter

L height

Detailed ways

Fig. 1 is an exploded schematic view of the screw and nut of the present invention; wherein the outer diameter of the screw 10 has a thread 11 fitted with a nut 20, and the inner diameter of the nut 20 has a thread 21 to match the thread 11 of the screw 10 , the rolling element 40 rolls between the threaded teeth 11 and 21 of the screw rod 10 and the nut 20, and the return unit 30 is inserted in the return flow hole 22 of the nut 20, so that the rolling element 40 can turn back to flow. Complete the cycle.

Fig. 2 is a schematic diagram of the rolling path of the rolling body on the screw of the present invention; wherein the thread teeth 11 of the screw 10 are divided into two parts: a crest 111 and an alveolar 112, and a single alveolar between two adjacent crests 111 of the screw 10 Two rows of rolling elements 40 are formed in 112 to roll, and the two rows of rolling elements 40 also complete the recirculation movement in the same alveolar 112 .

3 is a schematic cross-sectional view of the nut of the present invention; wherein the rolling elements 40 form two rows in the threaded teeth 21 of the nut 20, and roll in the tooth grooves 212 between two adjacent crests 211, and the reflow unit 30 makes the The rolling paths of the rolling elements 40 on both sides of the tooth crests 211 of the nut 20 can be connected to each other and turn back to complete the circular movement.

FIG. 4 is a detailed view of the backflow unit in FIG. 1; the backflow unit 30 straddles the two threaded teeth 21 tooth grooves 212 adjacent to the nut 20, and the backflow unit is also on the end surface that cooperates with the screw rod 10 in FIG. 1 A turning path 31 is provided, and the turning path 31 is formed into a U-shaped path by the auxiliary block 32 and the stop block 33, so as to connect the rolling paths of two rows of rolling bodies (not shown) in the single tooth groove 112 of the screw rod 10, so that the two rows The rolling elements complete the return circulation movement. The auxiliary block 32 is an extension of the crest 211 of the nut 20 in FIG. 3 , which makes the rolling body turn smoothly; and the stopper 33 is the obstruction of the original rolling path of the rolling body, so as to force the rolling body to turn back.

Fig. 5 is the synoptic diagram of screw rod and nut thread of the present invention and rolling body; Wherein it can be seen that the crest 111 of the thread thread of screw rod 10 is arranged in the tooth groove 212 of corresponding nut 20, and the thread thread of nut 20 The crests 211 of the teeth are arranged in the alveolar 112 of the corresponding screw rod 10, so that the rolling elements 41, 42 are separated by the crests 111 and 211 and roll in two rows in the alveoli 112 and 212. At this time, the alveoli 112 and the One of the columns in 212 is the rolling element 41 in the unloaded state, and the other row is the rolling element 42 in the loaded state. The rolling element 42 in the loaded state can be turned back into a rolling element in the unloaded state by means of a return unit (not shown). body 41, so the two rows of rolling bodies 41 and 42 rolling in the tooth grooves 112 and 212 roll in a complete cycle.

Fig. 6 is a schematic diagram of another embodiment of Fig. 5; Fig. 7 is a detailed view of the rolling elements in Fig. 6; wherein the rolling elements 41, 42 are also separated by tooth crests 111 and 211 to form two rows and roll in the alveolar 112 and 212, the main difference is that the rolling elements 41 and 42 have an inclination angle α, and the tooth peaks 111 and 211 that are in contact with the rolling elements 41 and 42 also have an inclination angle α to match the rolling elements 41 and 42, which can Make rolling elements 41 and 42 roll more smoothly. The inner diameter D ₁ shown in the figure is the thread root diameter of the screw 10, the major diameter ψ _o is the major diameter of the rolling elements 41 and 42, the minor diameter ψ _i is the minor diameter of the rolling elements 41 and 42, and the height L is the diameter of the rolling elements 41 and 42. When the rolling is smooth and the rolling body rolls 360° on the screw, the total number of rolling circles of the rolling body * the circumference of the rolling body must be equal to the circumferential length of the rolling body rolling on the screw, so it needs to satisfy (D _i /ψ _i ) =[(D ₁ +2L)/ψ _o ], it can be seen from Figure 7 that tanα=[(ψ _o -ψ _i )/(2L)], so the inclination angle α=tan ^-1 [(ψ _o -ψ _i )/(2L)].

The above detailed description is a specific description of the feasible embodiment of the present invention, but the embodiment is not used to limit the patent scope of the present invention, and any equivalent implementation or change that does not deviate from the technical spirit of the present invention shall be included in this case within the scope of the patent.

To sum up, this case is not only innovative in terms of space type, but also can enhance the above-mentioned multiple functions compared with conventional technologies, which should have fully met the statutory requirements for a novelty and progressive invention patent.

Claims (6)

1. rolling screw, comprise screw rod, nut and rolling element, its screw rod external diameter has a worm tooth, nut is sleeved on the external diameter of screw rod, nut is hollow shape, its internal diameter has a worm tooth that matches with aforesaid screw flight tooth, the screw thread sound of baby talk peak of aforementioned nut is placed in the corresponding screw flight sound of baby talk groove, aforesaid rolling element is arranged between aforesaid screw rod and the corresponding worm tooth of nut, being formed with two row rolling elements in single alveolus moves towards different direction, and nut is provided with a reflux unit, it is across in the two adjacent worm tooth alveolus of this nut, this reflux unit has the single-revolution path in addition, and connects the rolling path of aforesaid two row rolling elements with rotary path, makes aforesaid two row rolling elements can finish the reflux cycle motion in the single alveolus of screw rod.

2. rolling screw according to claim 1 is characterized in that: this rolling element is a roller.

3. rolling screw according to claim 2 is characterized in that: this roller tool α angle.

4. rolling screw according to claim 3 is characterized in that: have (D between this roller and the screw rod _i/ Ψ _i)=[(D _i+ 2L)/Ψ _o].

5. according to claim 1,2,3 or 4 described rolling screws, it is characterized in that: the tooth peak tool α angle of this worm tooth, α=tan ^-1[(Ψ _o-Ψ _i)/(2L)].

6. rolling screw according to claim 1 is characterized in that: this rolling element is a ball.

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