JPS5861352A - Ball screw with ball spline for fine speed further accurate feed - Google Patents

Abstract

PURPOSE:To perform relatively fine speed feed, corresponding to a lead difference between screw nuts respectively screwed to both ball screw threads, by providing the ball screw threads with a lead difference in two places and ball spline in the end part of said threads on a single shaft. CONSTITUTION:The first screw groove 13 and the second screw groove 14 are simultaneously rotated in accordance with rotation of a shaft 10. The first movable ball screws 15, 16 and the second movable ball screws 18, 19 are moved advancing both to the left direction in accordance with rotation of the first and second screw grooves 13, 14. However, the first movable ball screws 15, 16 are gradually separated by the distance corresponding to a lead difference, that is, the first movable ball screws are moved backward to the right direction by the lead difference, on the contrary, the second movable ball screws 18, 19 are moved forward to the left direction, and the ball screws are separated (virtual displacement) from each other.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention resides in a ball screw characterized in that the speed of the ball screw moving forward or backward by the rotation of the shaft is determined by the lead difference between the threads formed on the shaft. The present invention relates to a power transmission mechanism that enables slow and precise transmission using a single shaft.

Conventionally, the switching devices for rapid traverse, fine and close traverse p have used a transmission mechanism with complicated gears or a combination with a worm gear, that is, a mechanism in which the axes intersect at right angles.These mechanisms are complicated. requires considerable space,
Moreover, it is extremely difficult to create a highly accurate feeding mechanism.

In addition, the speed at which the cutting tool, table, or workpiece moves from side to side can be determined by applying power transmission to the base shaft using a complex structure such as gears, belt chains, link mechanisms, cam mechanisms, etc. This is difficult because the entire structure becomes large, and maintenance and inspection are not easy since it is difficult to assemble it into a mechanical device.

The object of the invention is to provide two screw grooves with different leads and a ball spline on the tail of the shaft, to move the ball screw forward or backward when the shaft rotates, and to adjust the speed of the forward and backward movement. The object of the present invention is to provide a power transmission mechanism that enables minute speed feed corresponding to the lead difference between the two ball screws, and further simplifies the entire mechanism to enable extremely minute feed.

That is, when the thread groove of the lead lO- and the thread groove of the lead S1 are set on the fist shaft, the lead difference is 0.1 sardine.

When the shaft rotates, one ball screw moves in the same direction or in the opposite direction.

Conventional mechanisms are very complex and require a large number of parts or feeding mechanisms, so they cannot be assembled compactly, and the mechanical parts are complex and use a large number of parts, resulting in overlapping problems such as crush # or part accuracy errors. Bamboo is difficult to use for precision feeding.

In the present invention, the term "r ball screw" refers to a preloaded ball screw.

The preloaded ball screw has good rotational strength, low frictional force, and easy rotation, which is a characteristic of its long life. (See Figure 4 (a), Cd) rifA) Also, “
"Ball spline" means that a large number of balls are interposed between the spline shaft and the outer cylinder, and the axial movement of the seat is 1
This means that the rotational torque of the shaft can be transmitted to the tube outer cylinder by itself.

(Fig. 3 B), (Rumors) In addition, the term "lead" in the *invention refers to a shaft formed with "screw grooves" that fit into each other via a large number of balls, and a "nut" formed with a threaded groove similar to that of the shaft. '' is the distance traveled when one side is fixed and the other side is rotated around its axis.

According to the present invention, by using a ball screw and a ball spline, there is almost no backlash, and the mechanism is extremely simple and the number of parts is small, so extremely precise feeding is possible.

In the present invention, a non-movable ball screw means that the nut portion cannot be moved by rotation of the ball screw.

The gist of the structure is that a spline is formed on one side of the shaft, and at least two screw grooves are formed on the left and right sides of the shaft at arbitrary intervals on the ttlt side, and then a lead is formed on the shaft and the simple shaft. The difference is Tob, and a ball screw corresponding to each lead is screwed together, and a ball spline is not fitted to the spline. The spline has at least two screw grooves formed on the left and right sides of the spline at arbitrary intervals, and the shaft and the screw grooves formed on the shaft have a lead difference and correspond to each lead. In a ball spline ball screw in which two ball screws are screwed together, and a ball spline is fitted into a spline member, the inner movable ball screw of the ball screw is engaged with the movable member, and the rear non-movable ball screw is engaged with the movable member. The ball screw is held in a housing, and the spline is rotatably attached to the rear end of the housing via a ring member, and a driving member is attached to the outer periphery of the ball spline. It is often used in power transmission mechanisms for slow and precise feeding.

A preferred example of the present invention is shown below based on the diagram! i52 Clarification: 10 is a shaft, and one side of the shaft 10 has a spline 11. On the other hand, a first thread groove 13 and a W42 thread groove 14 are formed on the right side and the W42 thread groove 14 on the left side as viewed from the figure, with an arbitrary interval 12 between them.

There is a lead difference between the thread of the first thread groove 13 and the thread of the m2 thread groove 14, that is, the lead of the second thread groove 14 is IJ.
It is formed larger than the lead of gl screw groove 13.

Double nut type ball screws 15 and 16 are screwed into the wIJ1 screw groove 13 via balls.

The ball screws 15 and 16 are disposed in the middle of the shim plate 171 on the left and right sides. (w44 Figure 83. r) Reference W/A
) A ball spline 211jj is fitted to the outer periphery of the spline 11 via balls, and the shaft 10 formed with the spline 11t is slidably disposed, and when a rotational force t-n is applied to the ball spline 21, the shaft 10 is fitted via the balls. The shaft 10 is rotated clockwise or counterclockwise.

Next, we will discuss the basic structure of non-invention, that is, the effect of the 111th invention.

The shaft lO in Figure 1 is the bearing (
On the right side, the ball spline is rotatably held by a frame or housing (not shown), or the shaft part extended through the spline shaft F is rotated and reciprocated on a bearing. The t-condition is that it is movably supported, and that both the first and second ball screws are movable ball screws.

Next, when a rotational force is transmitted to the spline 21 in a counterclockwise direction (left rotation) while the ball spline 21 is held in a fixed position, the spline shaft 11 is rotated together with the ball spline 21.

Said C77)! With 00 rotations, the first screw groove 1
3 and the second screw groove 14 rotate simultaneously.

1. It! As the second screw groove 13.14 rotates, both the w41 movable ball screw 15.1t$ and the second driven ball screw 18.19 move forward to the left, but the first movable ball screw 15.16 In other words, the IRI movable ball screw moves back to the right due to the lead difference, while the second movable ball screw 18° 1 bolt moves to the left and moves away from each other (
apparent displacement).

Also, when the shaft 10 rotates clockwise (right rotation), the first movable ball screw 15, 16 and the island 2 movable ball 1
8.19d both move forward to the right, or the first movable ball screw 15.16 is spaced apart by an amount corresponding to the lead difference, in other words, the lR1 movable ball screw moves forward to the left according to the lead difference. On the other hand, the second movable ball screws move back to the right and approach each other.

Advantageously, the first movable ball screw and the W42 movable ball screw move forward or face each other relative to the shaft, so that they approach each other and become tb or apart from each other as described above.

Therefore, if the cutting tool is fixed to the table on the two movable ball screws with the applied knee sandwiched between the two movable tables, both sides of the workpiece can be cut and ground at the same time. What can be done in terms of processing?

It can also be used as a robot arm by attaching an arm instead of a cutting tool.

Next, the second invention will be explained by station.

The ball screws 22 and 23 in FIG. 142 are fitted into the first screw grooves 13 of the shirt 10 in such a manner that they are sandwiched between the shim plate 24t and arranged on the left and right sides.

Simple ball screw 22. ! The fixed side nousing 26 is fitted onto the outer periphery of the housing 7 frame 28f of the housing.
The seven flange 25 of the ball screw 22 is fixed to the bordering end face via a screw 27t.

Therefore, the ball screws 22 and 23 become non-movable ball screws and are held in the housing 26.

By forming the rear end of the frame 28 of the housing 26 into a substantially convex shape on the KM surface in the axial direction, a cylinder 1129.30 with a size of p is formed.
or formed.

A ring 311 is fitted into the large cylindrical surface 29 of the bait and fixed to the cylindrical surface 29 with a screw 34.

A hollow inner unit 3 is provided on the rear fIIA surface 32 of the housing 26.
It is fixed via 3t-screw 35t-.

The diameter of the hollow circle 117I33 is formed to be somewhat larger than the rear end (f1320 diameter) of the housing 26.

An annular body 3607 with a cross section that fits the ll-shaped recess between the star ring 31 and the hollow circle 1ii33, and a hollow circle 1i391 that fits into the flange 37t and the open end 3B of the annular body 36.
- Fit and fix the hollow circle - 391 - via the screw 40.

A horizontal scale 41 is formed on the outer peripheral surface of the noble ring body 36 that is in contact with the end surface of the shell ring 31.

The flange 42 of the ring 21 is fixed via screws 43t.

Reference numeral 44 denotes a key, which is fitted onto the outer periphery of the ball spline 21 and fixed to a post 45.

The arm 471 of the handle 46 is attached to the position of the post 450.

Reference numeral 48 denotes a moving member such as a table, which is fixed with a screw 49 after being fitted onto the outer periphery of the @2 movable ball screw 18. The moving member 48 is moved by rotation of the handle 46. When the υ sea' r7) 10 is rotated to the left, the spline shaft 11 is rotated together with the ball spline 21, and at the same time, the ring body 36 with a curved cross section connected to one end of the ball spline 21 is inserted into the annular recess of the housing. No power is transmitted to the non-movable ball screws 22 and 23.

The shaft 10 moves back (towards the right in the figure) while being guided by the @1 thread groove 13 of the stationary ball screw 22, 23 (fixed to the housing).

Further, the second movable ball screw 18, 19, which is threaded into the second thread groove 14 formed on the left-rotating shaft 10, is advanced to the left in the figure.

The second movable ball screw 18, 19 is the non-movable ball screw 2.
2.23, the speed of the second movable ball screw 18.19 is a slow feed that compensates for the lead difference of the non-movable ball screw 22.2B.

For example, the lead of a non-movable ball screw 22.23 or 10.1
Then, the second Tl11 dynamic ball screw 18.1 for this
Assuming that the pitch of 9 is 1000, l@2 movable bow
The screw speed is 18.190 and the difference is 0.1.

In the ball screw of the present invention, [as shown in Figure 4, the left and right nuts are fastened together by several bolts, so there is no pack lash between the nuts that have threaded holes as well as the shaft that formed threaded holes. As shown in Fig. 3, the ball spline of the present invention has load balls arranged so as to sandwich the protrusions of the third thread of the spline shaft from the left and right, so that no preloaded ball screw is used. A preloaded ball spline with no lash is used. Therefore, when the rotational force t-m is applied by the handle to the ball spline without any play between the two as shown in FIG. 2, the responsiveness corresponding to the movement of the ball screw which is fed at a very low speed is excellent.

In addition, when changing the direction of the slow feed, there is no play at all, so it has good followability.In addition, due to the movement of the ball screw nut or fast feed according to the power of six people, @10 times the thrust is generated. What special effect can it give to Natsu?

In addition, since the minute speed feeding mechanism is constructed from a combination of extremely few parts, the present invention aims to provide a ball spline ball screw that is easy to maintain and manage and has fewer failures.

Also, the above ball screw has high rigidity.

It has an exceptional effect that can withstand long-term use because it allows accurate v1p measurement and there is no wear.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional front view showing the basic structure of the mechanism of the present invention. Figure $R2 is a partially sectional front view showing an applied configuration of the second invention. Figure 3 shows the ball spline used in the mechanism of the present invention. (
A) is a cross-sectional side view taken along the line A in FIG. Front view 2 (b) is marked A-A.
It is a line sectional view. lO: Shaft ll: Spline f7} l3: First thread groove 14: Second thread groove 15.16: vI41 Movable ball screw 1$, 19: Second movable ball screw 22.23: Non-movable ball screw % needle - Figure 3 (a) Figure 4 (a) (mouth)

Claims (1)

[Scope of Claims] (1) The shaft has a spline on one side, and at least two screw grooves are formed on the left and right sides at a predetermined interval on the other side, and the screw groove formed on the shaft has a lead. There is a difference, and the ball screws corresponding to each lead are screwed together, and the spline side is connected to the ball spline! A ball screw with a ball spline for slow and precise feeding with Ik. (2) A spline is formed on one side of the shaft, and at least two or more threads are formed on the left and right sides at an arbitrary interval t- on the other side, and the tI shaft has a shape i! In a Ball Spline ball screw in which there is a lead difference in the exploded screw groove, a ball screw corresponding to each lead is screwed together, and a ball spline is fitted into the spline plate, the ball Among the screws, a movable ball screw is added to the movable member, a rear non-movable ball screw is held in a housing, and the ball spline is rotatably attached to the rear end of the housing via a ring member, A power transmission mechanism for slow and precise feeding, characterized in that a rotational drive member is additionally provided on the outer periphery of the ball spline. (8) The ring member has a roughly U-shaped cross section and has a scale on the outer circumferential surface on the removal side! A power transmission mechanism for slow and precise feeding as described in Section 2 of the desired range.