JPS62127556A - Ball coupling composite traction drive - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a traction drive device, and more particularly to a drive traction device with improved volume, sheathing, and a convenient device for changing the rotation ratio. be.

BACKGROUND OF THE INVENTION Traction drives utilize smooth, continuous surface rolling elements to provide a predetermined rotational ratio between input and output members. The components of the device are normally lubricated with a traction fluid such as Monsanto Thrissa/Todrac fluid. Typically,
These include synthetic high traction alicyclic hydrocarbons. The traction coefficient of this fluid is 50 degrees higher than that obtained from normal mineral oil. This coefficient represents the maximum available traction force that would be available at the contacting female interface and is a measure of the maximum available driving torque. Exceeding this torque results in undesirable high slippage. Slips of 5% or less are normal for Taisei's traction drive systems. Although these drives are sometimes referred to as "non-slip", in reality they always have a small amount of micro-creep.

The various drive elements in conventional traction drives are shaped in a variety of shapes, the most popular being annular, conical, and slender. Many of these devices are
It is combined with conventional gear elements to provide a predetermined rotation ratio.

However, conventional traction drives exhibit a number of undesirable characteristics.

For example, nutation drive assemblies that utilize two single-acting conical sections, often bulky and with undesirable diameters, lengths, volumes, and envelopes, that roll within two fixed rings; This is normal.

This configuration of drive elements is also complex to assemble. Another bulky compound transmission uses four fixed cones that are loaded against a movable roller and impart rotation to said movable roller.

This configuration also utilizes a combination of gearing and traction drive to provide an overall rotational ratio.

Another example is a dual pulley transmission that uses a pair of steel V-belts to drive the power output for traction. This drive is also bulky and complex even when restricted to a single drive rate.

NASA's Lewis Research Center has developed a novel traction drive system consisting of a single-stage satellite roller with two rows of five-stage satellite rollers trapped between a concentric center roller and an annular roller. . Although this transmission is compact, it does not offer the advantage of adjusting the rotation rate.

(C) Structure of the Invention The present invention provides a variable ratio traction and drive device that achieves the required rotation ratio using a set of geometrically simple skew shafts, which is provided on an input carrier member and is separated. The outer rings, one half of which is attached to the frame and the other half of which is adapted to drive a drive ball captured between the rings forming the outer member. The resulting drive device fits compactly within the cavity of an internal member, such as a pancake torque device. The device of the present invention is mechanically simple, and the rotation ratio can be easily changed by changing the ball shaft skew angle.

OBJECTS OF THE INVENTION It is therefore an object of the present invention to - provide a variable ratio traction drive device capable of achieving the required rotation ratio by means of a set of geometrically simple skewed shafts, which are mounted on an input carrier member and 2, one half of which is fixed to the frame and the other half captured between split outer rings forming the output member;
The goal is to provide a complete drive unit with two drive balls. The drive of the present invention fits neatly into the cavity of an internal drive, such as a pancake torque device.

The device of the present invention has a simple structure and is movable to easily adapt to changes in rotation ratio by changing the ball shaft skew angle.

(e) Examples of the invention Next, embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, the ball-coupled compound traction drive has an input carrier member 1, which has outer bearings with race rings 6 and 1.
A set of balls 7 is supported in the 0 via bearings 8, the ring 6 being fixed to a housing member 15 and the outer ring 10 being a preload diaphragm 11. It is fixed to the housing member 14 via the output member 12 and the bearing 50 of the output member.

The drive motor armature 2 has a drive input position resolver armature 4.
It is attached to the input member 1 in the same way. Obviously, alternating current motors or additional drive motors or gear means, means such as thumbwheels, as well as further sensing devices (angular position, velocity or acceleration sensing devices) can be mounted on the input member 1. . In the illustrated embodiment, the & excitation motor and position resolver stators 3 and 5 are respectively mounted on the housing member 14.15.

The rotation ratio between the input member 1 and the output member 12 is
(by the position of the ball rotation axis 13 with respect to the rotation axis 19).

Figure 2 shows the analysis diagram. In FIG. 2, due to the skew of the ball rotation axis 13 at an angle θ, the contact points 17 and 1
6 resulting in a different turning radius of 20°21. The radius of rotation of the two ring members 10 and 6 in FIG.
In the figure, it is represented by 22°23, and does not change even if the skew angle changes. The rotation radii 22 and 23 are the same.

The location of the contact point 16 is determined by the rotation 4a19 of the input member, the radius of rotation 26 of the ball 7, and the dimension 27 of the axis of the ball 7.
determined by the central radial offsela) m1m25,
and is located at an angle α.

The rotation ratio TR between the output member 12 and the input member 1 is expressed by the following formula.

Once the angle α is determined in the design, the pole skew angle 0 can be adjusted by adjusting the ball carrier element 9 shown in FIG.
It is chosen to effect a rotation ratio change by replacing it. The ball rotation axis 15 is controlled by the pole carrier elements 9, but these elements? is carrier bearing 8
The ball 7 is supported through. The two elements 9.9 are identical but assembled 180° apart as shown in FIG.

FIG. 5 shows characteristic curves of the rotation ratio TR when α is 30°, 45°, and 60°. As can be seen from Figure 5, 1:1 to 8
A rotation ratio of 0=1 or more is easily achieved by adjusting or changing the pole skew angle θt-.

The pole skew axis θ can be changed by substituting an alternative member 9 into the input member 1 as shown in FIG.

With full reference to FIG. 1, the support ball 7 is preloaded at two contact points 16 and 17 on the fixed ring 6 and the output ring 10 via the preload diaphragm 11t. The drive torque obtained by the drive is determined by the input torque and the rotation ratio is less than that which causes the slip at interfaces 16 and 17.

This limiting torque is determined not only by the traction coefficient, as mentioned above, but also by the normal loads acting on the ball 7 at the contact points 16 and 17. This load is applied to the output member 12 in axial relation to the housing 141C by the adjusting nut 18 acting through the carrier bearing 50.
is generated by positioning the . The axial position of the output member relative to the position of the output ring 10 determines the axial deflection of the diaphragm 11 and thus the ball 7'f
! : through which the threshold axial preload of members 10 and 6 is determined.

The input member 1 is 1. Not only is it supported on all axes by the drive traction mechanism, but it can also fit compactly within the armature cavity of a conventional pancake micro-torque machine, for example. This can provide an ideal mechanicalization of the drive reduction device within the necessary envelope for the armature of the torque device.

The drive mechanism according to the invention provides a less complex means than is necessary for other traction drives to achieve a given rotation ratio. Additionally, ball bearing analysis and fabrication techniques are well established and can be directly applied to the traction drive of the present invention.

The absence of slender cones and shafts used in conventional traction and drive systems increases the angular stiffness of the system. The angular play that exists in other drive devices of this type is reduced to zero.

In the case of very large output torques, which require a significant axial preload, the support bearing 8 of the ball 7 has difficulty accommodating the radial load.

FIGS. 4 and 4a show a configuration in which the radial load component of the axial load is applied via the ball 7, thereby reducing the above component.

In FIG. 4, the skew axis 13 of the ball 7 is maintained as previously described, but the radial load component of the axial load is applied via the floating internal load ring 28 through all internal contact points 29. do.

The apparatus in FIG. 4 is an alternating current drive means, whereby the 1M drive motor shown in FIG. This configuration gives a shadow to the additional rotation ratio T' between the outer member 12 and the inner member 1 expressed by the following equation.

E = pitch diameter of ball 7 d = diameter of ball Figures 5 and 5a show modified examples of the rotation prevention means for attaching the bearing race ring 6 to the nozzling member 15.
1 is a partial sectional view similar to FIG. 1; In this modification, the cam angle β of the member 6 acting on the ball 28 is
as a result of the driving torque resulting in a specific adjustment of the position of the race ring 6 relative to the housing member 15.

This axial position change increases the directional load on the ball Z by the diaphragm 11 as a load, resulting in an increase in the traction coupling ability to drive with increased torque without undue slippage. The relationship between the axial load change Y and the drive torque T is as follows.

However, C=constant based on design parameters.

By choosing the relevant nine-ball skew angle θ,
Another means of fully setting a given rotation ratio can be realized with an arrangement as shown in FIGS. 6 and 6a.

The post 30 attached to the seventh flange of the member 1' is terminated by a sweep ball 51 which guides the ball carrier 32. The ball carrier 32 has two positioning flats 54.
A guide arm 33 having a positioning ball 35 is provided. The flat portion 34 fits into a radial groove 36 at the twenty-seventh flange of the member 1'. These c-blue not only prevent rotation of the ball carrier 32 about the axis of the swivel ball 31, but also allow pure movement of only the guide arm 33. The adjustment plate 37 is fitted via the ball 35 into an angular guide groove 38 which captures the guide arm 35 . This adjustment plate 3
7 is guided on the journal 39 of the input member 1' and the collar 4
It is locked by tightening 0. The ball skew angle θ can be adjusted by rotational adjustment of member 67 relative to the flange of member 1'. This adjustment affects the axis θ of the ball 7, so that equal rotation ratio adjustment is performed for each ball 7. A suitable means of calibration for this rotation adjustment and resulting rotation ratio is as shown in FIG.
1 may be provided. In FIG. 6a, the adjustment groove 38 of the member 67 is configured with a slope and a change in shape to provide a given rotation ratio sensitivity. Increasing the angle β in FIG. 6a decreases the rotation ratio adjustment sensitivity of member 37. This is because a given rotation of member 37 relative to groove 36 results in a small change in skew angle θ and thus results in a rotation ratio.

The arrangement shown in FIG. 6a is a six drive ball arrangement; another variation could include seven balls.

[Brief explanation of drawings]

FIG. 1 is a half cross-sectional view of an embodiment of the present invention, FIG. 2 is the structure of the drive section shown in FIG. 1, and FIG. 5 is related to two of the design parameters shown in FIG. 4 and 4a are cross-sectional views of floating radius load acting members and alternative drive means for high torque levels; FIGS. 1, which provides preload adjustment to accommodate high torque tolerances; FIG. 6 is a modification of the device of FIG. 1 that provides rotation ratio adjustment without replacement of parts; An example. FIG. 6a is a cross-section of the configuration shown in FIG. (In the figure) 1 is an input carrier member, 2 is a drive motor armature, 6
and 5 is a position resolver stator, 4 is a resolver 'Shinko Kame, 6 is an outer race ring, 7 is a set of balls, 8 is a bearing,
9 is a ball carrier bearing, 10 is an outer race ring, 11 is a preload diaphragm, 14 is a housing, and 18 is an adjustment nut. Patent applicant Suberi Corporation FIG, 1゜FIG, 2゜FIG. 6A. (DEGI θ

Claims (1)

Claims: 1) In a ball-coupled composite traction drive with a variable rotation ratio, a plurality of geometrical a skewed shaft drive ball, the first outer link being fixed to the housing and the second outer link forming a rotatable output member, and further preloading first and second outer race rings. and means for selecting the amount of torque to be transmitted from the input carrier member to the output carrier member. 2) A traction drive device according to claim 1, in which the axial drive ball is adjusted geometrically skewed with respect to the axis of rotation of the input carrier member, so that the rotatable input carrier member and the The traction drive device is characterized in that the rotation ratio between the rotation output member and the rotation output member is changed. 3) Traction drive according to claim 2, characterized in that the preload means are adjusted as a traction of the output torque.