JPH06207653A - Power transmitting device - Google Patents

Abstract

PURPOSE:To facilitate pre-load control and reduce the number of parts and cost by providing a pair of thrust bearings on the outer periphery of a fixed shaft coaxial with a driven shaft and attaching a transmitting element supported on the driven shaft to the outer ring of the bearing to cause the end face of the fixed shaft to abut against a casing body. CONSTITUTION:A shaft part 1 of a fixed shaft 6 at the side of a hollow cylindrical driven shaft 32 opposed to a turnable surface is adapted to abut against the bottom 2 of a casing 33 to be fixed by a bolt 3. A cam follower 36 is disposed in the driven shaft 32 and a pair of tapered roller bearings 38 are fited left and right (above and below) with reference to the position of the follower 36 at a predetermined interval. Turrets are attached to the outer rings of the tapered roller bearings 38 with reference to a projecting part 4 with a stage holding a predetermined interval. In the adjustment of pre-load the depth side tapered roller bearing 38 is inserted on the fixed shaft 32 and the cam follower 36 is attached to the outer ring. The other tapered roller bearing 38 is attached and the cam follower 36 is disposed in the central part of both bearing 38, 38 to be assembled after set up pre-load adjustment outside the casing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device, and more particularly to an index unit (intermittent indexing device), a worm speed reducer, a machine tool, or a drive unit of a machine, which sequentially applies a driving force via a number of planned positions. In a mechanism having a multiaxial structure of two or more axes orthogonal to each other in a casing of a device to be transferred, a predetermined preload (preload) of a bearing which receives a thrust force for holding each axis, a drive member of an orthogonal axis, and The present invention relates to a power transmission device capable of surely or easily performing the preload management in an inter-axis adjusting mechanism between axes of a driven member.

[0002]

2. Description of the Related Art Conventional preload control in orthogonal adjustment between axes, in other words, an appropriate preload is required between a driving member and a driven member, and an inspection window opened in a casing body is required to check the preload. is there. When the inter-axis adjustment is performed again based on the result of the inspection through the inspection window, it is necessary to attach and detach the casing of the device. Generally, the casing surrounding the power transmission device has a large amount of weight, and the larger the device, the more time and effort are required for the preload management. Further, it is known that it is extremely difficult to perform the preload management of one shaft, and then the preload management of the other shaft orthogonal thereto, in the inter-axis adjustment. That is, even if one shaft can be attached to the casing as a single unit to measure the preload, if the other shaft orthogonal to this is set, the preload is applied between the driving member and the driven member and the preload is attached to the other shaft. For example, in a bearing that receives a thrust force, a preload of a driving member and a driven member occurs in an arbitrary direction in addition to a preload, and it is extremely difficult to measure the preload required for a bearing that receives a specific thrust force. I was supposed to.

FIG. 2 shows an indexing mechanism using a globoidal cam which is particularly difficult to adjust.
They are (a) and (b).

FIG. 2 (a) is a partial sectional view showing a surface orthogonal to the output shaft, and FIG. 2 (b) is a partial sectional view showing a surface orthogonal to the input shaft. In such a conventional index device, an input shaft 31 and an output shaft 32 are orthogonal to each other and are rotatably supported by a casing 33. A globoidal cam 34 is integrally attached to the input shaft 31, and a cam follower 36 is in contact with a taper rib 35 of the globoidal cam 34.

A plurality of cam followers 36 are provided radially on the outer peripheral surface of a turret shaft 37, which is integrated with the output shaft 32, at predetermined intervals, and two adjacent cam followers 36 are provided.
Both side surfaces of the taper rib are sandwiched between two cam followers 36. The cam follower 36 includes a support shaft 36a and a roller 36 rotatably supported by the support shaft 36a.
b), and a support shaft is planted on the outer peripheral surface of the turret shaft 37 and is fixedly supported by this.

In order to adjust the degree of orthogonality between the input shaft 31 and the output shaft 32 that are orthogonal to each other in such a configuration, a pair of conical roller bearings 38 that hold the input shaft 31 and a globoidal cam that is axially supported by the input shaft 31. Since the point of action of the driving force of 34 is at the center of the output shaft, the both-sided support for supporting both sides of the point of action is generally a stable supporting method. In this double-supported state, a pair of conical roller bearings 38 that support the output shaft are fitted into the inner wall of the housing 33, and then the respective members are finally set in the casing 33 to set the input shaft 31. It is necessary to adjust the preload between the members. This requires the labor required for the preload adjustment described above and a high degree of skill in managing the preload in the casing. That is, the workability is extremely poor because the adjustment management is performed in the inspection window when each member is finally set.

On the other hand, in order to avoid the preload control from the inspection window opened on the casing, FIG. 3 illustrates another conventional example of assembling the input shaft and the output shaft.
The conventional example shown in FIG. 3 is a structure for performing the adjustment management shown in FIG. In the conventional example of FIG. 2, preload control can be performed only after finally setting each member. That is, in order to stabilize the rotational drive of the output shaft, the bearing cases themselves are arranged on both sides of the cam follower in order to dispose the support members on both sides of the cam follower pivotally supported by the output shaft. Such an arrangement relationship necessitates measuring the preload on the bearing and the input member after the final setting of the output member, which is disadvantageous in that the casing must surround each member. Therefore,
The inspection window is inevitably required by providing an opening in a part of the casing.

From this point of view, FIG. 3 shows that the above-mentioned inconvenience has been avoided by once preliminarily carrying out the external preparation of the members around the output shaft. It is necessary to temporarily set the peripheral member of the output shaft outside the casing, and dispose a pair of bearings on one front side in the insertion direction with respect to the position of the cam follower as a bearing for supporting the output shaft. That is, one end of the output shaft that abuts on the closed bottom needs to be a free end when set in the casing, and the rotational drive of the output shaft is cantilevered by the cam follower. This means that a runout of the output shaft on the side opposite to the support bearing is produced, and thus another bearing 39, one end of which is supported, is required to supplement this runout. Furthermore, an accessory 40 (a washer nut or the like) 40 that abuts the end face of the bearing is required to compensate for the displacement of the bearing due to the thrust direction. That is, the number of parts is larger than that of the both-end support of the rotary shaft, new machining accuracy is required, and the cost is increased.

[0009]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above, and preload management is performed outside the casing of either the drive shaft or the driven shaft orthogonal to each other. However, the preload between the driven member and the driven member after assembly can be controlled very accurately and easily, and in addition, the driven member is arranged in the approximate center of the fixed shaft in order to reduce the number of parts and the cost of the device. Then, a pair of bearings that receive thrust force on the outer periphery of the fixed shaft are arranged on both sides,
A transmission element axially supported by a driven member of an outer ring of the bearing that receives the thrust force is mounted, and an end surface of the driven shaft is abutted and fixed to the casing body of the device, and a predetermined position is hung from a table surface of the casing body. The invention provides a power transmission device that is divided into two parts.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below.

FIGS. 1 (a) and 1 (b) are partial cross-sectional views showing a plane perpendicular to a drive shaft and a driven shaft of a power transmission device according to the present invention. Although the description is omitted, the roller gear indexer will be described in particular for one embodiment of the present invention.

The end portion 1 of the fixed shaft 6 on the side of the driven shaft 32 of the hollow cylinder facing the turntable surface abuts the bottom portion 2 of the casing 33 and is screwed and fixed by the bolt 3. Further, a cam follower 36 is arranged on the driven shaft 32, and a pair of conical roller bearings 38 are fitted to the left and right (upper and lower) at predetermined intervals with reference to the position of the cam follower. A turret is mounted on the outer ring of the conical roller bearing 38 with reference to the protrusion 4 having a step for holding the predetermined distance.

On the other hand, as described with reference to the index mechanism of the conventional globoidal cam, the globoidal cam 34 having the tapered rib 35 is inserted into the input shaft 31, and the tapered rib of the cam has a straight portion and a twisted portion. In the straight line portion, the cam follower does not move and the output shaft 32 is completely locked to be in a stopped state, and in the twisted portion, the cam follower 36 is moved to output the output shaft 3
2 performs indexing.

Further, the housing 33 is divided into a lid at a predetermined position A hanging toward the turntable (not shown) side, and after all the members are set, they are integrally connected with the casing body 33 via the oil seal 5. To be done.

On the other hand, a gap between the casing 33 and the driven shaft 32 is sealed in order to seal the gap between the members of the cam follower 36 axially supported by the driven shaft and to seal the lubricating oil filled in the inside of the roller gear indexer. The oil seal 5 is enclosed.

A method of setting up the preload of each of the above-mentioned members in the above structure will be described.

Regarding the adjustment method of preload control in the inter-axis adjustment, as described above, the inter-axis adjustment mechanism is necessary in addition to the preload control of the tapered roller bearings of the drive shaft and the driven shaft in the mechanism of the present invention. Along with this, the driving member and the driven member also need to be adjusted in the thrust direction with respect to their respective shafts. An eccentric mechanism is adopted as a method for adjusting the distance between the shafts. In this case, the conical roller bearing case 6 supporting the drive shaft is used.
The inner circumference is processed with an eccentricity (offset) with respect to the outer circumference. For this reason, the casing is also eccentrically eccentrically bored, and the conical roller bearing case is rotated to reduce or extend the distance between the shafts.

Therefore, it is clear that if the conical roller bearing case is rotated even a little, a deviation occurs with respect to the true center line, and accordingly, it is necessary to align the position of the driven member with the center line of the drive member. . Usually, a shim or the like is inserted between the casing and the case of the driven shaft conical roller bearing, but it may be performed by a lock nut or the like. Further, it is necessary to adjust the thrust direction of the drive shaft at the same time in the same manner as the driven shaft.

Such a complicated adjustment can be preliminarily set up outside the apparatus, and at least one of the orthogonal axes can be adjusted, and then the other axis can be incorporated into the casing of the apparatus main body in a state where it is already set. Is a feature of the present invention.

As a preload adjusting method of the present invention, a fixed shaft 32 which supports a driven portion outside the casing main body.
A cam follower 3 axially supported by a driven member 7 that is fitted with a conical roller bearing 38 on the inner side of the stepped groove engraved on the outer periphery thereof and is further rotationally externally inserted on the outer ring of the bearing 38.
6 is attached. Further, the conical roller bearings 38 on the front side of the other device are inserted into the gap between the outer circumference of the fixed shaft 32 and the inner circumference of the driven member 7 with a predetermined gap, and the cam follower 36 causes the pair of conical roller bearings. The cam follower is supported on both sides by being distributed to both sides of the driving action point of the cam follower so as to be located at the substantially central portion. After such an integral outer setup is performed on the fixed shaft 6, the pair of conical roller bearings 38, and the driven member 36, this integral adjusted member is set to the drive member orthogonal thereto. The integrated driven member is inserted until it abuts on the bottom bottom of the casing body 33,
Fine adjustment is performed by a shim or the like in the axial direction parallel to the driven shaft so as to have a predetermined preload with the drive member.

In this way, after the adjustment of each driving member and driven member is completed, the lid body 8 of the case body divided into two parts described above is closed by bolts.

[0022]

As is apparent from the above description, according to the power transmission device of the present invention, a pair of conical roller bearings are arranged on the outer periphery of the driven shaft on which the turret is axially supported with the driven member as a reference, and the conical roller bearing is provided. A turret in which a cam follower is externally inserted is axially supported by the outer ring of the roller bearing, and the end surface of the driven shaft and the casing body of the present apparatus are brought into contact with each other, and the predetermined position depending from the table surface is divided into two parts. The drive shaft and the driven shaft are separately set outside the casing, and preload control after assembly can be performed very accurately and easily, and the number of parts can be extremely reduced and the cost of the device can be saved.

[Brief description of drawings]

FIG. 1 (a) is a partial sectional view showing a power transmission device of the present invention in a plane perpendicular to a driven shaft. Figure 1
(B) is a partial cross-sectional view showing the power transmission device of the present invention in a plane perpendicular to the drive shaft.

FIG. 2 (a) is a partial sectional view showing a conventional globoidal device in a plane perpendicular to a driven shaft. FIG. 2B is a partial cross-sectional view showing the conventional globoidal device in a plane perpendicular to the drive shaft.

FIG. 3 is a partial sectional view showing a globoidal device for explaining another conventional supporting method in a plane perpendicular to the drive shaft.

[Explanation of symbols]

 1 End 2 Bottom 3 Bolt 4 Projection 5 Oil Seal 6 Fixed Shaft 7 Driven Member 8 Lid 31 Drive Shaft 32 Driven Shaft 33 Case Body 34 Globoidal Cam 35 Tapered Rib 36 Cam Follower 37 Turret Shaft 38 Tapered Roller Bearing 39 Ball Bearing

[Procedure amendment]

[Submission date] March 16, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Figure 1]

[Fig. 2]

[Fig. 2]

[Figure 3] ─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 24, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Figure 1]

[Fig. 2]

[Fig. 2]

[Figure 3]

Claims (2)

[Claims] 1. In a power transmission device having at least two or more orthogonal drive shafts and driven shafts in a casing, a pair of bearings for receiving a thrust force is arranged on the outer periphery of a fixed shaft coaxial with the driven shafts. A transmission element pivotally supported by the driven member of the outer ring of the bearing that receives the thrust force is mounted,
A power transmission device characterized in that an end surface of the fixed shaft and a casing body are fixed by abutting against each other. 2. The power transmission device according to claim 1, wherein the casing body is divided into predetermined positions that hang down from a surface facing the surface on which the fixed shaft is abutted and fixed.