JP2015121317A - Ball screw device including wiper ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ball screw device including a wiper ring.SOLUTION: A ball screw device includes a screw shaft 1, a nut 2 and a wiper ring 3, the screw shaft 1 has a long structure extended in one direction, a rolling groove 11 is formed on a surface of the screw shaft 1, the nut 2 is provided with a through hole 21 penetrating through the long shaft 1, a rolling groove 211 corresponding to the rolling groove 11 is formed on an inner edge face of the through hole 21, the rolling groove 11 and the rolling groove 211 configure a load passage 90, and positioning grooves 23 are formed on both end faces 24 of the nut 2. Mounting grooves 212 are formed on both ends of the through hole 21, rolling elements 4 are disposed on the load passage, a recessed groove 31 is formed on an end face of the wiper ring 3, the recessed groove 31 defines a main body portion 32 and a lock portion 33 at both ends, the main body portion 32 accommodates the mounting groove 212, the lock portion 33 accommodates a positioning groove 22, the main body portion 32 has a communication hole 321, a lip portion 322 is formed on an inner edge face of the communication hole 321, the nut 2 has a fixing member, and the fixing member is kept into contact with the lock portion 33 at one end.

Description

  The present invention relates to a wiper ring of a ball screw device, and more particularly to a ball screw device provided with a wiper ring that can prevent false pre-pressure from being fixed by looking at the wiper ring.

  The ball screw device uses a ball or rolling element to drive the relative movement between the screw shaft and the nut, and has the advantages of low friction and high accuracy. If any dust or dust enters, the action and accuracy of the ball screw will be adversely affected, so dust prevention measures are very important. For this reason, conventionally, a dustproof technique for a ball screw device has been developed. Among them, as shown in FIG. 1, in this conventional technique, an annular wiper ring B is provided at one end of the nut A, and the nut A has two parts. Two screw holes A1 are opened along the radial direction, and the two screws A2 are respectively threaded through the two screw holes A1 so that the wiper ring B is sandwiched from both sides by the two screws A2, It is designed to be fixed in the nut A. Thus, the lip B1 of the wiper ring B can be accommodated in the rolling groove C1 of the screw shaft C of the ball screw device. When the ball screw device is actuated, the lip B1 of the wiper ring B functions to wipe off foreign matter generated in the rolling groove C1 as the screw shaft C rotates, and dust and dust enter the rolling groove C1. It is possible to prevent the entry, keep the ball screw clean, and operate with high accuracy.

  By the way, when actually used, this type of wiper ring has the following drawbacks.

(1) When installing the wiper ring, make it extremely close to the screw shaft C. Although it is ideal to make it non-contact, it is quite difficult to control the mounting force and the mounting depth. If A2 is inserted too deeply into the screw hole A1, the wiper ring is pressed from both sides, and the lip B1 of the wiper ring B is pressed against the rolling groove C1 of the screw shaft C. This preload is called a false preload). The false pre-pressure here means that the pressure is not previously adjusted between the screw shaft, the nut and the rolling element in the ball screw device, that is, the lip B1 is pressed against the rolling groove C1. By generating the acting force, the user misidentifies that the ball screw has a pre-pressure, and this acting force is temporarily generated, and the lip B1 is in contact with the rolling groove C1. After the wear has occurred, this acting force disappears, thus affecting the operating accuracy of the device.
When the screw shaft C rotates, friction is constantly generated between the lip B1 and the rolling groove C1, and the wiper ring B is formed of a plastic material lower than a metal having high hardness. Therefore, the lip B1 generates a high heat and deforms due to the above-mentioned constant friction, or is crushed and worn to become wear powder. For this reason, there is a problem that not only the destruction of the wiper ring B but also the operation accuracy is affected by the wear powder.

  (2) If the two screws A2 are too shallowly inserted into the screw hole A1, the wiper ring B is liable to loosen, and thus falls off.

  (3) When installing the wiper ring, the lip B1 of the wiper ring B must be placed in the rolling groove C1 of the screw shaft C, and the wiper ring B must be aimed so as to maintain a certain clearance. Because it is necessary to adjust the depth at which the two screws A2 are screwed together so as to avoid contact between the lip B1 and the rolling groove C1, finally succeeding by repeating a number of tests by trial and error Can do. For this reason, there has been a problem that it takes a lot of time and labor to attach the wiper ring, and the unexpected cost increases.

None

  The present invention has been made in view of the above problems, and the object thereof is to easily maintain a gap between the wiper ring and the rolling groove and fix the wiper ring by screwing with a screw. An object of the present invention is to provide a ball screw device provided with a wiper ring that can avoid false preload due to excessive acting force or fixing force.

  In order to solve the above problems, the present invention is a ball screw device provided with a wiper ring, including a screw shaft, a nut, a plurality of rolling elements, and two wiper rings, wherein the screw shaft is It is a long strip structure extending in one direction, and this extending direction is defined as an axial direction. A spiral rolling groove is provided on the surface of the screw shaft, and the long shaft is provided on the nut. A through hole is provided to pass through, and another rolling groove corresponding to the rolling groove is provided on an inner edge surface of the through hole, and the rolling groove and the another rolling groove have a single load path. And annular positioning grooves are provided on both end surfaces of the nut in the axial direction, mounting grooves are provided on both ends of the through hole in the axial direction, and the rolling elements are provided in the load path. Installed, the axial end of the wiper ring has a recessed groove, The concave groove is defined as a body part and a lock part on both sides, the body part accommodates the mounting groove, the lock part accommodates the positioning groove, and the body part includes the screw. A communication hole penetrating the shaft, and an inner edge surface of the communication hole is provided with a lip portion extending toward the rolling groove, wherein the nut includes a fixing member, The fixing member is a ball screw device provided with a wiper ring, one end of which is in contact with the lock portion.

  Here, the fixing member is a screw, and a screw hole communicating with the positioning groove is provided on the surface of the nut. The screw hole serves to screw the screw, and the front end of the screw is It is preferable to press the lock portion.

  Here, it is preferable that a bottom surface of the concave groove is supported by an end surface of the nut.

  Here, a gap is provided between the lip and the rolling groove, and the gap is preferably 0.01 to 0.04 mm.

  The present invention adopts a combination structure of a wiper ring and a nut, so that when the wiper ring is attached and fixed by a fixing member, the wiper ring is brought into contact with the lock part without directly applying pressure to the main body part. The ring can be fixed. In addition, by receiving the bottom surface of the concave groove on the end face of the nut, a constant gap is maintained between the lip and the rolling groove, positioning is performed quickly, and contact between the lip and the rolling groove is achieved. It is possible to avoid the wear of the lips by increasing the resistance force during operation of the ball screw device.

It is a longitudinal cross-sectional view of the ball screw apparatus provided with the wiper ring of the prior art. It is a whole exploded view of a ball screw device provided with a wiper ring of the present invention. It is an assembly figure of the ball screw device provided with the wiper ring of the present invention. It is a longitudinal cross-sectional view of the ball screw apparatus provided with the wiper ring of this invention.

  For a better understanding of the features and technical contents of the present invention, please refer to the description of the implementation method of the present invention and the drawings. However, this implementation method and drawings are for explanation and reference, and these do not impose any limitation on the present invention.

  Referring to a preferred embodiment 1 of the present invention shown in FIGS. 2 to 4, the present invention is a ball screw device having a kind of wiper ring, which includes a screw shaft 1, a nut 2, and a plurality of A rolling element 4 and two wiper rings 3 are included.

  The screw shaft 1 is defined as an elongated structure extending in one direction, and the extending direction is defined as the axial direction X. On the surface of the screw shaft 1, a spiral rolling groove 11 is provided. .

  The nut 2 is provided with a through hole 21 that penetrates the long shaft 1, and an inner edge surface of the through hole 21 is provided with another rolling groove 211 corresponding to the rolling groove 11, and the rolling The groove 11 and the another rolling groove 211 constitute one load path 90, and annular positioning grooves 22 are provided on both end surfaces 24 in the axial direction X of the nut 2, respectively. Attachment grooves 212 are provided at both ends in the direction X, respectively. The rolling element 4 is installed in the load path 90.

  One end surface of the wiper ring 3 in the axial direction X is provided with a concave groove 31, and the concave groove 31 is defined as a main body portion 32 and a lock portion 33 on both sides, respectively. The mounting groove 212 can be accommodated, the lock portion 33 can accommodate the positioning groove 22, and the main body portion 32 has a communication hole 321 that passes through the screw shaft 1, and an inner edge surface of the communication hole 321. Is provided with a lip portion 322 that protrudes and extends toward the rolling groove 11.

  In the present embodiment, as a method for fixing the wiper ring 3, a screw hole 23 communicating with the positioning groove 22 is formed on the surface of the nut 2, and the screw hole 23 is used to screw the screw G. Yes. In addition, the front end of the screw G presses the lock portion 33. As shown in FIG. 4, after the wiper ring 3 is fixed to the nut 2 and the wiper ring 3 is attached, the bottom surface 311 of the concave groove 31 is in close contact with the end surface 24 of the nut 2. Further, a certain gap is provided between the lip 322 of the wiper ring 3 and the rolling groove 11. In addition, the gap is preferably 0.01 to 0.04 mm depending on the standard of the ball screw device. The present invention is not limited to the screw hole and screw screwing method employed in the present embodiment, and the wiper ring 3 may be fixed by other lock structure methods.

  As described above, by adopting the wiper ring and nut combination structure, when the wiper ring is attached and fixed, the screw presses the lock part of the wiper ring, and the lip part of the wiper ring is the wiper ring. By forming a fixed gap between the screw shaft and the rolling groove of the screw shaft, the contact between the lip and the rolling groove is avoided, and the ball screw device is activated. The resistance of the lips can be increased, and wear due to the lips can be avoided.

<Invention>
1: Screw shaft 11: Rolling groove 2: Nut 21: Through hole 211: Rolling groove 212: Mounting groove 22: Positioning groove 23: Screw hole 24: End face 90: Load path 3: Wiper ring 31: Concave groove 311: Bottom surface 32: body portion 321: communication hole 322: lip portion 33: lock portion 4: rolling element G: screw X: axial direction T: gap <conventional technology>
A: Nut A1: Screw hole A2: Screw B: Wiper ring B1: Lip C: Screw shaft C1: Rolling groove

Claims (4)

A ball screw device with a wiper ring,
Including a screw shaft, a nut, a plurality of rolling elements, and two wiper rings,
The screw shaft is an elongated structure extended in one direction, and this extending direction is defined as an axial direction, and the surface of the screw shaft is provided with a spiral rolling groove,
The nut is provided with a through hole that penetrates the long axis, and an inner edge surface of the through hole is provided with another rolling groove corresponding to the rolling groove, and the rolling groove and the another rolling groove are provided. The dynamic groove constitutes one load path, annular positioning grooves are provided on both end surfaces in the axial direction of the nut, and mounting grooves are provided on both axial ends of the through hole,
The rolling element is installed in the load path,
A concave groove is formed in one end surface of the wiper ring in the axial direction, and the concave groove is defined as a main body part and a lock part on both sides, respectively, and the main body part accommodates the mounting groove, The lock portion accommodates the positioning groove, and the main body portion has a communication hole penetrating the screw shaft, and an inner edge surface of the communication hole extends and protrudes toward the rolling groove. Lips are provided,
Among them, the nut has a fixing member, and one end of the fixing member comes into contact with the lock portion, and the ball screw device having a wiper ring is provided.   The fixing member is a screw, and a screw hole communicating with the positioning groove is provided on the surface of the nut. The screw hole serves to screw the screw, and the front end of the screw is the locking portion. The ball screw device with a wiper ring according to claim 1, wherein the ball screw device is pressed.   The ball screw device with a wiper ring according to claim 1, wherein a bottom surface of the concave groove is supported by an end surface of the nut.   The ball screw device with a wiper ring according to claim 1, wherein a gap is provided between the lip and the rolling groove, and the gap is 0.01 to 0.04 mm. .