JP2013119922A - Ball screw device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make fixing force of a seal member uniform to reduce risks of deforming and breaking of a low-rigidity seal member and form the seal member into a compact and simple shape.SOLUTION: A ball screw device 1 includes a housing section 22 provided on both sides of a nut 20; a seal member 50 which comprises a lip section 52 sliding on an outer circumferential surface of a screw shaft on an inner circumferential side of an annular body and is housed in a housing section 22; a face plate 60 which has an annular form with an outer diameter equal to or less than an outer diameter of the seal member 50 and is located on a shaft end side of the screw shaft in relation to the seal member 50 to be housed in the housing section 22; and a plurality of fixing members each comprising a wedge-shaped apical end 70a for pressing the face plate 60 against the seal member 50 by the axial force of the screw shaft when being driven from an outer circumferential side of the face plate 60 to come in contact with an outer circumference of a lateral side 60a of the face plate 60, and a stepped portion 70c for regulating a driving amount of the apical end 70a driven from the outer circumferential side of the face plate 60 by a locking operation between the lateral side 60a and outer circumference of the face plate 60.

Description

  The present invention relates to a ball screw device including a seal member at an end portion of a nut.

In FIG. 15, the structural example of the sealing member 50 attached to the edge part of the nut of a ball screw apparatus is shown. As shown in FIG. 15, the seal member 50 has a lip portion 52 that slides on the outer peripheral surface of the screw shaft of the ball screw device on the inner peripheral side of the substantially annular body portion 51.
Here, in the sealing member 50 which is resin-molded and easily deformed such that the thickness of the main body 51 is 2 mm or less, there is a possibility that desired performance cannot be exhibited if it is deformed when fixed to the nut end. Therefore, in order to suppress deformation when the seal member 50 is fixed, do not apply a fixing force other than compressive force (axial force) to the seal member as much as possible, apply the fixing force uniformly in the circumferential direction, and make fine adjustments. It is desirable to satisfy the conditions such as being able to do so.

Here, Patent Document 1 discloses a technique for managing the fixing force of the seal member with the clearance Δβ by causing the seal member to protrude from the face plate seating surface of the nut by the clearance Δβ. Furthermore, Patent Document 1 discloses a technique for providing a protrusion at a contact portion of the face plate with the seal member in order to prevent the displacement of the seal member.
Patent Document 2 also discloses a technique for providing a protrusion at a contact portion of the face plate with the seal member.

  Patent Document 3 discloses a technique for fastening a seal member and a face plate together with bolts and fixing them to a nut.

JP 2008-309173 A Japanese Patent Laid-Open No. 11-166608 Japanese Utility Model Publication 2-71156

  However, with the technique disclosed in Patent Document 1, the fixing force of the seal member greatly changes even if the clearance Δβ changes by 0.1 mm. Therefore, when the dimensional stability of the sealing member is not good due to resin molding or the like, the fixing force is increased, and a large compressive force is generated on the sealing member, and the face plate may be greatly bent. Therefore, when a sealing member having low rigidity and easily deforming shape is fixed by such a technique, the sealing member 50 may be deformed together with the face plate 60 as shown as a change from (a) to (b) in FIG. There is.

In order to solve such a problem, it is conceivable to reduce the rigidity of the face plate by making the face plate thin. However, in this case, the face plate is likely to be distorted. A big difference appears in the fixing force. In this case, the fixing force of the seal member cannot be made uniform in the circumferential direction.
In addition, it is conceivable to manage the fixing force of the seal member with the bolt tightening force. However, in this case, since the bolt is not tightened, it is difficult to equalize the tightening force of each bolt for stopping the face plate. There is a possibility that it cannot be fixed with uniform force.

Further, when the projection is provided on the face plate, the force concentrates on the contact portion between the seal member and the projection on the face plate, and therefore the seal member may be deformed by the projection on the face plate. In addition, the provision of the protrusions on the face plate leads to an extra cost increase. Also in Patent Document 2, problems similar to these occur.
Here, it is conceivable to provide a fixing claw (protrusion) on the seal member side, but the cost increases because the seal member has a complicated shape. Furthermore, since the thickness cannot be made constant when the seal member is resin-molded, the seal member may be distorted.

In addition, the technique disclosed in Patent Document 3 is not realistic because it is necessary to reduce the bolt tightening force to reduce the fixing force of the seal member, which leads to loosening of the bolt.
Further, the technique disclosed in Patent Document 3 cannot be applied to a seal member having no space for providing a through hole for a bolt. Therefore, when the sealing member of the configuration example shown in FIG. 15 is fixed by the technique disclosed in Patent Document 3, the sealing member 50 has a wall thickness for forming the through hole 55 of the bolt as shown in FIG. It is necessary to form the part 54 in the outer peripheral part, and to form the through-hole 55 in a long hole so that the phase can be adjusted when fixed. In this case, the manufacturing disadvantage of the seal member 50 increases.

  The present invention has been made in view of the above-described problems, and its purpose is to make the fixing force of the sealing member uniform, reduce the risk of deformation and breakage of the low-rigidity sealing member, and make the sealing member compact. It is to make it a simple shape.

  In order to solve the above-mentioned problems, a ball screw device according to claim 1 of the present invention includes a screw shaft in which a spiral rolling element rolling groove is formed on an outer peripheral surface, and a helical shaft through which the screw shaft is inserted. A plurality of rolling elements formed on the inner peripheral surface of the rolling element rolling groove, and a rolling element passage formed by facing the rolling element rolling groove of the screw shaft and the rolling element rolling groove of the nut. A ball screw device having a rolling element, and a housing portion provided at both ends of the nut, and a sliding portion that slides on the outer peripheral surface of the screw shaft on the inner peripheral side of the annular body portion. A seal member housed in the housing portion, and an annular shape having an outer diameter equal to or less than the outer diameter of the seal member, the housing portion being positioned on the shaft end side of the screw shaft with respect to the seal member And the screw shaft in the face plate that is pushed in from the outer peripheral side of the face plate A wedge-shaped pressing portion that presses the face plate against the seal member by an axial force of the screw shaft when contacting the outer peripheral portion of the side surface on the shaft end side, and the pressing portion is pressed from the outer peripheral side of the face plate A plurality of fixing members having a restriction portion that restricts the amount of the face plate by being engaged with the outer peripheral portion of the side surface of the screw shaft on the shaft end side of the face plate.

According to a second aspect of the present invention, the ball screw device according to the first aspect is the ball screw device according to the first aspect, wherein the fixing member is a pointed setscrew, and the pressing portion is formed of the pointed setscrew. It is a front-end | tip part, The said control part is a boundary part of the column-shaped main-body part of the said pointed setscrew, and the said front-end | tip part, It is characterized by the above-mentioned.
According to a third aspect of the present invention, there is provided a ball screw device comprising: a screw shaft having a spiral rolling element rolling groove formed on an outer peripheral surface; and a spiral rolling element rolling groove through which the screw shaft is inserted. A nut formed on an inner peripheral surface, and a plurality of rolling elements that roll on a rolling element passage formed by facing the rolling element rolling groove of the screw shaft and the rolling element rolling groove of the nut. In the ball screw device, a housing portion provided at both ends of the nut and a sliding portion that slides on the outer peripheral surface of the screw shaft on the inner peripheral side of the annular body portion are accommodated in the housing portion. A seal plate, and a face plate that is formed in an annular shape having an outer diameter equal to or less than the outer diameter of the seal member and is positioned on the shaft end side of the screw shaft with respect to the seal member and accommodated in the accommodating portion The front of the face plate when it is formed of a low rigidity material and attached to the outer peripheral side of the face plate A plurality of fixing members that press the face plate against the seal member by an axial force of the screw shaft while deforming a predetermined amount of a contact portion with the outer peripheral portion of the side surface on the shaft end side of the screw shaft; It is characterized by having.

The ball screw device according to claim 4 of the present invention is the ball screw device according to claim 3, wherein the rigidity of the fixing member is a rigidity of a portion of the face plate where the low-rigidity member contacts the outer peripheral portion. It is characterized by being smaller than.
A ball screw device according to a fifth aspect of the present invention is the ball screw device according to any one of the first to fourth aspects, wherein the face plate has a contact portion with the fixing member in an outer peripheral portion. A groove that is concave in the radial direction is formed.

According to the ball screw device according to the first aspect of the present invention, each fixing member can make the pressing amount of the pressing portion equal to each other by the restricting portion, thereby applying an equal force to the entire face plate. It can be pressed against the seal member.
In the ball screw device according to claim 1 of the present invention, the sealing member can be fixed by the force in the direction perpendicular to the seat surface by the axial force of the screw shaft of the fixing member. Even if it has a low rigidity, the risk of deformation and breakage of the seal member can be reduced.

In the ball screw device according to claim 1 of the present invention, since it is not necessary to provide a fixing hole for fixing the seal member to the nut in the seal member, the seal member has a compact and simple shape. it can. Therefore, according to the ball screw device according to claim 1 of the present invention, for example, improvement in productivity can be expected by simplification.
Moreover, according to the ball screw device according to claim 2 of the present invention, the fixing member can be constituted by an existing member such as a pointed set screw.

Moreover, according to the ball screw device according to claim 3 of the present invention, since the fixing members can make the deformation amounts equal to each other, an equal force is applied to the entire face plate to press the face plate against the seal member. be able to.
In the ball screw device according to claim 3 of the present invention, the seal member can be fixed by a force in a direction perpendicular to the seating surface by a force in the axial direction of the screw shaft of the fixing member. Even if it has a low rigidity, the risk of deformation and breakage of the seal member can be reduced.

In the ball screw device according to claim 3 of the present invention, since it is not necessary to provide a fixing hole for fixing the seal member to the nut in the seal member, the seal member has a compact and simple shape. it can. Therefore, according to the ball screw device according to claim 1 of the present invention, for example, improvement in productivity can be expected by simplification.
In the ball screw device according to claim 4 of the present invention, it is possible to prevent the face plate side from being deformed and to ensure that the amount of deformation of each fixing member is equal to each other. The face plate can be pressed against the sealing member by applying an even force to the sealing member.

  In the ball screw device according to claim 5 of the present invention, the fixing member can be positioned closer to the center of the main body of the seal member, so that the axial force of the screw shaft of the fixing member can be increased. It can be made to act on the center position of the main-body part of a sealing member, or its vicinity. Thereby, in the ball screw device according to the fifth aspect of the present invention, the main body portion can be prevented from being displaced in the radial direction.

It is sectional drawing which shows the structural example of the ball screw apparatus of 1st Embodiment. It is sectional drawing which shows the edge part detail of the nut in 1st Embodiment. It is a front view of the ball screw device of a 1st embodiment. It is a figure which shows the detail of the contact site | part of a set screw and a face plate. It is a figure which shows the relationship between a set screw and a face plate at the time of fixing a face plate with a set screw. It is a figure which shows the ball screw apparatus provided with the face plate which provided the groove | channel in the outer periphery. It is a front view which shows the example of the faceplate which provided the groove | channel in the outer periphery. It is a figure which shows the force added to a face plate from a set screw, Comprising: (a) is a figure which shows the case where a groove | channel is provided in outer periphery, (b) is a figure which shows the case where the groove | channel is not provided in outer periphery. It is a figure which shows the structural example which provided the fixing location by a set screw four places at equal intervals in the circumferential direction. It is sectional drawing which shows the structural example provided with two sealing members in the accommodating part. It is sectional drawing which shows the structural example which attached the case which accommodated the sealing member and the faceplate to the edge part of a nut. It is a figure which shows the structural example of the ball screw apparatus of 2nd Embodiment. It is a figure used for description of the effect | action etc. in 2nd Embodiment. It is a figure which shows the example provided with the faceplate which provided the groove | channel in the outer periphery in 2nd Embodiment. It is a figure which shows the structural example of a sealing member. It is a figure used for description of the problem in the past. It is a figure which shows the example of the sealing member in which the thick part for forming the through-hole and through-hole of a volt | bolt in the outer peripheral part was formed.

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
First, the first embodiment will be described.
The first embodiment is a ball screw device to which the present invention is applied.
(Constitution)
1 to 3 are diagrams showing a configuration example of the ball screw device 1 according to the first embodiment. FIG. 1 is a cross-sectional view of the ball screw device 1 as viewed from the side. FIG. 2 is a cross-sectional view showing details of the end of the nut 20 in the ball screw device 1. FIG. 3 is a front view of the ball screw device 1.

As shown in FIGS. 1 to 3, the ball screw device 1 includes a screw shaft 10, a nut 20, and a ball 30.
The screw shaft 10 is a substantially cylindrical rod-like body, and a female screw (spiral) ball screw device groove is formed on the outer peripheral surface. Correspondingly, the nut 20 has a substantially cylindrical shape, and a female screw (spiral) ball screw (not shown) is provided on the inner peripheral surface at a position facing the ball screw device groove of the screw shaft 10 in the radial direction. A device groove is formed. A spiral rolling element passage 40 on which the ball 30 rolls is formed between the nut 20 and the screw shaft 10 by the ball screw device groove of the nut 20 and the ball screw device groove of the screw shaft 10. The nut 20 is formed with a lubricant injection path 21 for injecting lubricating oil into the spiral rolling element passage 40. The nut 20 is provided with a seal member 50 and a face plate 60 for fixing the seal member 50 to the end of the nut 20 at both ends.

In the sealing member 50, a lip portion 52 that slides with the outer peripheral surface of the screw shaft 10 is formed on the inner peripheral side of the substantially annular body portion 51.
The face plate 60 also has a substantially annular shape. The inner diameter of the face plate 60 is slightly larger than the inner diameter of the lip portion 52 of the seal member 50, and the outer diameter is slightly larger than the outer diameter of the seal member 50 (main body portion 51). The face plate 60 contacts the main body 51 of the seal member 50 over the entire circumference. Here, the face plate 60 and the main body 51 of the seal member 50 may be partially brought into contact, for example, by providing a recess on the side surface of the face plate 60 facing the main body 51 of the seal member 50.

The seal member 50 and the face plate 60 are accommodated in the accommodating portions 22 formed at both ends of the nut 20 so that the face plate 60 is positioned on the shaft end (hereinafter simply referred to as the shaft end) side of the screw shaft 10. And fixed by a set screw 70.
The accommodating portion 22 has an inner peripheral diameter larger than that of the inner peripheral surface portion where the ball screw device groove is formed in the nut 20. A set screw mounting hole 23 a is formed in the peripheral wall 23 of the housing portion 22. Specifically, a set screw mounting hole 23a is formed in the peripheral wall 23 at a position offset by a distance L1 on the axial end side with respect to the position of the side surface 60a facing the axial end of the face plate 60 accommodated in the accommodating portion 22. Has been. As shown in FIG. 3, the set screw mounting holes 23 a are formed at equal intervals in the circumferential direction at the end 23 of the nut 20.

  The set screw 70 is a set screw 70 at the pointed end, and is screwed and attached to the set screw attaching hole 23a. When the outer peripheral portion of the side surface 60 a facing the shaft end side of the face plate 60 hits the tip end portion 70 a of the set screw 70, the seal member 50 is housed and fixed in the housing portion 22 together with the face plate 60.

Next, the structure and operation of fixing the face plate 60 with the set screw 70 will be described with reference to FIGS.
FIG. 4 is a diagram illustrating details of a contact portion between the set screw 70 and the face plate 60. FIG. 5 is a view showing the relationship between the set screw 70 and the face plate 60 when the face plate 60 is fixed by the set screw 70.
As shown in FIG. 4, in the set screw 70, the tip end portion 70 a hits the outer peripheral portion of the side surface 60 a facing the shaft end side of the face plate 60 accommodated in the accommodating portion 22. In this state, the distal end portion 70a of the set screw 70 acts as a wedge and presses the face plate 60 in three directions of the radial direction, the axial direction, and the circumferential direction, so that the seal member 50 is fixed to the housing portion 22 together with the face plate 60. The Here, the force by which the tip 70a of the set screw 70 presses the contact portion with the face plate 60 is divided into a radial component indicated by an arrow R and an axial component indicated by an arrow X, and the force of the radial component is caused by the face plate 60. Everything is received. Therefore, the force that the seal member 50 receives from the set screw 70 via the face plate 60 is only the force of the axial component from the set screw 70. Therefore, the seal member 50 is fixed by the force of the axial component acting as a force in a direction perpendicular to the seat surface.

  Further, as shown in FIG. 5, when the set screw 70 is pushed in to fix the face plate 60, the distal end portion 70 a of the set screw 70 bites into the outer peripheral portion of the side surface 60 a of the face plate 60. However, since the stepped portion 70c at the boundary between the distal end portion 70a of the set screw 70 and the substantially cylindrical main body portion 70b functions as a stopper for restricting the amount of pressing of the set screw 70, the set screw 70 is provided on the outer periphery of the face plate 60. No more than a certain amount in the part. Therefore, the fixing force by each set screw 70 can be made equal by keeping the amount of biting (pushing amount) of the set screw 70 into the outer peripheral portion of the face plate 60 constant. That is, the seal member 70 can be fixed by applying a force evenly in the circumferential direction of the seal member 50.

  Further, for example, by changing the distance L2 from the seating surface 53 of the seal member 50 to the set screw 70, the amount of biting can be changed and the fixing force by the set screw 70 can be changed. Therefore, the fixing force by the set screw 70 can be easily adjusted by adjusting the distance L2. For example, the adjustment of the distance L2 is performed by adjusting the axial position of the nut 20 (for example, the distance L1) of the set screw attachment hole 23a provided in the peripheral wall 23 of the housing portion 22.

  In the above-described embodiment, the set screw 70 constitutes a fixing member, for example. Moreover, the front-end | tip part 70a of the set screw 70 comprises a pressing part, for example. Further, the stepped portion 70c of the set screw 70 constitutes a regulating portion, for example.

(Modification of the first embodiment)
Although the first embodiment of the present invention has been described, the first embodiment is not limited to this, and various changes and improvements can be made.
That is, in the present embodiment, a groove can be provided in a contact portion with the set screw 70 in the outer peripheral portion of the face plate 60. 6 and 7 are diagrams showing an example of the face plate 60 in that case. Here, Fig.6 (a) is sectional drawing seen from the side, FIG.6 (b) and FIG. 7 are front views.
As shown in FIGS. 6 and 7, three grooves 61 that are concave in the radial direction can be provided on the outer peripheral surface of the face plate 60 at equal intervals in the circumferential direction corresponding to the arrangement of the set screw 70.

8A shows the force applied from the set screw 70 to the face plate 60 provided with the groove 61 as shown in FIG. 8, and FIG. 8B shows the set screw applied to the face plate 60 not provided with such a groove 61. The force applied from 70 is shown.
As shown in FIG. 8B, in the case of the face plate 60 without the groove 61, the contact position between the set screw 70 and the outer peripheral portion of the face plate 60 corresponds to the outer peripheral position of the seal member 50 in the radial direction. The force of the axial component indicated by the arrow X that 70 pushes the face plate 60 acts on the outermost peripheral portion of the face plate 60, that is, the outermost peripheral portion of the seal member 50. Thereby, a rotational force in the direction of arrow F is generated in the seal member 50. For this reason, the seal member 50 may be displaced in the accommodating portion 22 by this rotational force.

  On the other hand, as shown in FIG. 8A, by providing the groove 61 on the outer periphery of the face plate 60, the contact site between the set screw 70 and the outer periphery of the face plate 60 moves to the center side in the radial direction, As a result, the axial component force indicated by the arrow X by which the set screw 70 pushes the face plate 60 is at or near the center of the main body 51 of the seal member 50, that is, the center of the fixed seating surface of the main body 51 of the seal member 50. Or it will join in the vicinity. As a result, the seal member 50 can be prevented from being displaced in the housing portion 22 due to the aforementioned rotational force.

  Moreover, in this embodiment, the fixing location by the set screw 70 is not limited to 3 locations. FIG. 9 is a diagram showing an example of the configuration. Here, Fig.9 (a) is sectional drawing seen from the side, FIG.9 (b) is a front view. As shown in FIG. 9, in the modified example of the present embodiment, four fixing points by the set screw 70 can be provided at equal intervals in the circumferential direction. Further, in the case of such a configuration, the above-described grooves 61 formed on the outer peripheral portion of the face plate 60 can be provided at four locations corresponding to the arrangement of the set screws 70.

Moreover, in this embodiment, it is not limited to providing the one sealing member 50, Two or more sealing members 50 can also be provided. FIG. 10 is a diagram showing a configuration example in which two seal members 50 are stacked in the accommodating portion 22. In such a configuration, the seal member 50 is more easily deformed.
Moreover, in this embodiment, the sealing member 50, the face plate 60, and the accommodating part which accommodated these can be attached to the nut 20 as a unit. FIG. 11 is a diagram illustrating a configuration example thereof.

As shown in FIG. 11, in the modification of the embodiment, a case 80 having the same shape as the end shape in which the accommodating portion 22 is formed in the nut 20 is attached to the end portion of the nut 20 with a bolt 81. .
Here, the case 80 has a substantially annular shape as a whole, and an insertion hole through which the screw shaft 10 is inserted is formed on the inner periphery. The case 80 is formed with an accommodating portion 80b similar to the end shape of the nut 20 described above. As a result, the seal member 50 and the face plate 60 are fixed to the accommodating portion 22 by the set screw 70 that is positioned on the shaft end side and screwed into the set screw mounting hole 80c on the peripheral wall.
In the present embodiment, the outer diameter of the face plate 60 can be made smaller than the outer diameter of the seal member 50.

(Second Embodiment)
Next, a second embodiment will be described.
The second embodiment is also a ball screw device to which the present invention is applied. In the second embodiment, the same components as those in the first embodiment will be described with the same reference numerals.
In the second embodiment, the face plate 60 is fixed by a bolt attached in the axial direction of the nut 20.
FIG. 12 is a diagram illustrating details of an end portion of the nut 20 in the ball screw device according to the second embodiment. Here, FIG. 12A is a cross-sectional view seen from the side, and FIG. 12B is a front view.

As shown in FIG. 12, in the second embodiment, the face plate 60 is fixed by a bolt 91 attached in the axial direction to the peripheral wall 23 of the accommodating portion 22 in the nut 20 via a washer 92 through which the bolt 91 is inserted. doing. Here, a bolt mounting hole 23b extending in the axial direction is formed in the peripheral wall 23 of the housing portion 22 of the nut 20, and the bolt to which the washer 92 is mounted is screwed into the bolt mounting hole 23b. Thereby, the outer peripheral part of the face plate 60 is pressed and fixed by the washer 92. Here, the washer 92 is made of a low-rigidity material. Specifically, the rigidity of the washer 92 is smaller than the rigidity of the outer peripheral portion of the face plate 60 pressed by the washer 92.
The other configuration of the ball screw device 1 of the second embodiment is the same as that of the ball screw device 1 of the first embodiment.

Next, the structure, operation, etc., of fixing the face plate 60 with such a bolt 91 with a washer will be described.
In the second embodiment, the force that the seal member 50 receives from the bolt 91 (washer 92) via the face plate 60 is mainly an axial component force that the bolt 91 (washer 92) presses the face plate 60.

Here, FIG. 13 shows a state when the bolt 91 is attached to the nut 20.
As shown in FIG. 13, the axial width of the accommodating portion 22 is narrower than the total thickness obtained by adding the thickness of the sealing member 50 and the thickness of the face plate 60. Therefore, in the axial direction of the nut 20, the side surface 60 a of the face plate 60 protrudes from the axial end surface 23 a of the peripheral wall 23 of the housing portion 22 that comes into contact with the seating surface 92 a of the washer 92. Therefore, as shown in FIG. 13A, a gap L3 formed between the side surface 60a of the face plate 60 and the seating surface 92a of the washer 92 when the washer 92 comes into contact with the side surface 60a of the face plate 60. As shown in FIG. 13B, the outer peripheral portion 92b of the washer 92 that is in contact with the side surface 60a of the face plate 60 may have low rigidity, and is deformed when the bolt 91 is completely tightened. At this time, the fixing force by the bolt 91 depends on the deformation amount (elastic force resulting from the deformation amount).

Therefore, even if the bolts 91 are completely tightened, the washer 92 is deformed only for the gap L3 described above, so that the fixing force by each bolt 91 can be made equal.
Further, the fixing force by the bolt 91 can be easily adjusted by adjusting the gap L3 by adjusting the axial width of the accommodating portion 22 and the total thickness of the seal member 50 and the face plate 60. Furthermore, by adjusting the rigidity of the washer 92 and the contact amount between the washer 92 and the face plate 60, the fixing force by the bolt 91 can be easily adjusted. For example, the rigidity of the washer 92 can be adjusted by adjusting the thickness and diameter of the washer 92, and the contact amount between the washer 92 and the face plate 60 can be adjusted by adjusting the diameter of the washer 92.

(Modification of the second embodiment)
Although the second embodiment of the present invention has been described, the second embodiment is not limited to this, and various changes and improvements can be made.
That is, in the second embodiment, as in the modification of the first embodiment, the groove 62 can be provided in the contact portion with the washer 92 in the outer peripheral portion of the face plate 60. FIG. 14 is a diagram showing an example of the face plate 60 in that case. Here, FIG. 14A is a sectional view seen from the side, and FIG. 14B is a front view. As shown in FIG. 14, three grooves 62 can be provided on the outer periphery of the face plate 60 at equal intervals in the circumferential direction corresponding to the arrangement of the bolts 91.

  As a result, the contact portion between the washer 92 and the outer peripheral portion of the face plate 60 moves to the center side in the radial direction. As a result, the force of the axial component that the washer 92 pushes the face plate 60 is applied to the main body 51 of the seal member 50. It is added at or near the center, that is, at or near the center of the fixed seat of the main body 51 of the seal member 50. As a result, the seal member 50 can be prevented from being displaced in the accommodating portion 22 due to the rotational force.

DESCRIPTION OF SYMBOLS 1 Ball screw apparatus 10 Screw shaft 20 Nut 22 Accommodating part 40 Ball 70 Set screw 70a Tip part 70c Step part

Claims (5)

A screw shaft in which a spiral rolling element rolling groove is formed on the outer peripheral surface, a nut in which the screw shaft is inserted and a spiral rolling element rolling groove is formed in the inner peripheral surface, and a rolling element of the screw shaft A ball screw device having a rolling groove and a plurality of rolling elements rolling on a rolling element passage formed by facing the rolling element rolling groove of the nut;
Receiving portions provided at both ends of the nut;
A seal member that has a sliding portion that slides with the outer peripheral surface of the screw shaft on the inner peripheral side of the annular main body portion, and is accommodated in the accommodating portion;
A ring plate having an outer diameter equal to or less than the outer diameter of the seal member, and a face plate accommodated in the accommodating portion located on the shaft end side of the screw shaft with respect to the seal member;
A wedge-like shape that is pressed from the outer peripheral side of the face plate and presses the face plate against the seal member by the axial force of the screw shaft when contacting the outer peripheral portion of the side face of the face plate on the shaft end side of the screw shaft. A plurality of fixing parts, each having a pressing part and a regulating part that regulates the amount by which the pressing part is pushed from the outer peripheral side of the face plate with the outer peripheral part of the side surface of the face plate on the axial end side of the screw shaft. Members,
A ball screw device comprising:   The fixing member is a pointed set screw, the pressing part is a tip part of the pointed set screw, and the restricting part is a columnar body part of the point set screw and the tip part. The ball screw device according to claim 1, wherein the ball screw device is a boundary portion. A screw shaft in which a spiral rolling element rolling groove is formed on the outer peripheral surface, a nut in which the screw shaft is inserted and a spiral rolling element rolling groove is formed in the inner peripheral surface, and a rolling element of the screw shaft A ball screw device having a rolling groove and a plurality of rolling elements rolling on a rolling element passage formed by facing the rolling element rolling groove of the nut;
Receiving portions provided at both ends of the nut;
A seal member that has a sliding portion that slides with the outer peripheral surface of the screw shaft on the inner peripheral side of the annular main body portion, and is accommodated in the accommodating portion;
A ring plate having an outer diameter equal to or less than the outer diameter of the seal member, and a face plate accommodated in the accommodating portion located on the shaft end side of the screw shaft with respect to the seal member;
When the screw shaft is attached to the outer peripheral side of the face plate, the contact portion of the face plate with the outer peripheral portion of the side surface on the shaft end side of the screw shaft is deformed by a predetermined amount while being deformed by a predetermined amount. A plurality of fixing members that press the face plate against the seal member by an axial force;
A ball screw device comprising:   4. The ball screw device according to claim 3, wherein the rigidity of the fixing member is smaller than the rigidity of a portion of the face plate that contacts the low-rigidity member of the outer peripheral portion.   The ball screw device according to any one of claims 1 to 4, wherein a groove that is concave in a radial direction is formed in the face plate at a contact portion with the fixing member in an outer peripheral portion. .

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