JPS6224107Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a plane bearing device in which the friction surface is a plane.

In general, plane bearing devices are used to perform smooth motion with low frictional resistance.For example, in industrial robots, in order to support the hand and arm that grips a workpiece so that they can move relatively freely, a flat bearing device is used between these two members. It has been intervened. That is, the planar bearing device allows the hand that grips the workpiece to be relatively moved in parallel, allowing the eccentricity of the workpiece to be operated efficiently. Self-lubricating plain bearings made of plastic materials are commercially available as such planar bearing devices.

However, in this type of conventional plane bearing device, since it is moved against sliding frictional resistance, it naturally cannot be moved when the external force is small. For this reason, a robot hand equipped with a conventional plane bearing device has the disadvantage that it is not always possible to efficiently manipulate a workpiece, and this has also been a hindrance to increasingly delicate robot operations.

This idea was created with these points in mind.
Three or more through holes are provided in one flat plate interposed between two members having parallel planes, and each through hole holds a steel ball, and each holds an elastic member that is elastically deformed by the rolling movement of the steel ball. To provide a plane bearing device capable of moving two members in parallel even with a small external force by an extremely simple configuration in which the flat plate is held in a state where a gap is formed between the two members. It is. The configuration and the like will be explained in detail below with reference to embodiments shown in the drawings.

FIG. 1 is a cross-sectional view showing the main parts of a robot hand in which a plane bearing device according to the present invention is installed. The holder 1 is formed into a cylindrical shape having a top portion, and a support portion 1a is provided protruding in the axial direction from the top portion. The lower part of this support part 1a is formed to have a smaller diameter than the base end part, and a collar is provided on the lower edge to protrude in the radial direction, and a seat surface 2 is provided on the periphery of this collar.

Reference numeral 3 denotes an eccentricity absorbing member formed in a substantially cylindrical shape, which is disposed so as to be movable in the axial direction and the radial direction by loosely fitting the small diameter portion of the support portion 1a into the opening in the upper end surface, and the peripheral edge of the opening. is provided with a seat surface for seating on the seat surface 2. On the other hand, a seat surface 4 on which a deflection angle absorbing member to be described later is seated is provided at the periphery of the opening in the lower end surface. 5 urges the eccentricity absorbing member 3 to the holder 1 via a regulating cylinder 6 which is itself disposed coaxially with the holder 1 and regulates the eccentricity absorbing member 3 to be coaxial with the holder 1. This is the first spring. A second spring 7 is set to have a stronger biasing force than the first spring 5, and biases the eccentricity absorbing member 3 against the eccentricity absorbing member 8, which is provided with a hand for gripping a workpiece (not shown). ing. That is, the hand is movably disposed relative to the arm by being biased by the eccentricity absorbing member 3 disposed movably relative to the holder 1 fixed to the arm. The deviation angle absorbing member 8 is formed into a cylindrical shape having a bottom, and has a spherical tip surface inside so that the deviation angle absorbing member 8 can swing in contact with the eccentricity absorbing member 3. A formed protrusion 9 is provided.

Reference numeral 10 denotes a plane bearing device interposed between the eccentricity absorbing member 3 and the regulating cylinder 6, which are coaxially arranged and have parallel planes. This plane bearing device 10
As shown in the plan view a and the enlarged sectional view b, at least three steel balls 11, 11, .
By rolling into contact with the and regulating cylinder 6, these two members are supported so as to be movable relative to the plane direction. Around these steel balls 11, 11..., sponges 12, 12, which are elastic members that have elasticity themselves and hold the steel balls 11 in a freely rolling manner, have a cylindrical shape to reduce frictional resistance with the steel balls 11. It is surrounded by a collar 13. When the eccentricity absorbing member 3 and the regulating cylinder 6 move relative to each other and the steel ball 11 rolls, the sponge 12 is elastically deformed without hindering this movement.

Reference numeral 14 denotes a disc as a single flat plate interposed between the eccentricity absorbing member 3 and the regulating cylinder 6. A central hole 16 is bored in the center of this disc 14, through which the support portion 1a of the holder 1 passes, and at least three through holes 15, 15, . . . are bored at equal intervals on the outside thereof. has been done. A sponge 12 for holding the steel ball 11 is loaded and held in each through hole 15. Disc 14 and sponge 12 are steel balls 11
The outer circumferential surface of the disc 14 contacts the inner circumferential surface of the regulating tube 6, thereby forming gaps g, g between the eccentricity absorbing member 3 and the regulating tube 6. It is maintained in the same condition. Therefore, even when the sponge 12 is elastically deformed, it is not subjected to frictional resistance.

In the plane bearing device configured in this way, the work gripped by the hand provided on the eccentricity absorbing member 8 receives an external force, and the first spring 5 is compressed and deformed, and the workpiece is moved to the holder 1 of the eccentricity absorbing member 3. When the seating of the workpiece is released, the eccentricity absorbing member 3 can be moved in the radial direction even if the external force acting on the workpiece is small. That is, the plane bearing device 1
0 is not caused by sliding as in the past, but by steel ball 1
This is because the resistance is extremely small compared to sliding friction because it is due to the rolling of No. 1. At this time, the steel ball 11 itself naturally moves due to rolling, but since the steel ball 11 is surrounded by the elastically deformable sponge 12, the sponge 12 elastically deforms as the steel ball 11 moves. ,
There is nothing that impedes the rolling of the steel ball 11.
Here, since the sponge 12 does not come into contact with the eccentricity absorbing member 3 and the regulating cylinder 6, the frictional resistance generated when the steel ball 11 rolls is minimized, and the movement of the steel ball 11 is made smoother. I can do it. Further, since the plurality of sponges 12 are directly held by one disc 14, the number of parts can be suppressed from increasing.

Note that the elastic member is not limited to a sponge, and may be any material having the same function.

Fig. 3 is a plan view and b sectional view showing another embodiment of the plane bearing device. In these figures, the same members as those shown in Figs. 2 a and b are given the same reference numerals and their explanations are given. is omitted. 17 is a spiral spring as an elastic member surrounding the steel ball 11, and the steel ball 11 provided at the center of this spiral spring 17 is
It can be elastically deformed as it rolls and moves.

As explained above, according to the present invention, three or more through holes are provided in one flat plate interposed between two members having parallel planes, a steel ball is held in each through hole, and the steel ball is rolled and moved. Since the flat plate is held with a gap formed between the two members, the friction generated when the steel ball rolls is minimized and the steel ball is rolled smoothly. By rolling the steel ball, the two members can be moved in parallel, and the movement of the steel ball can be absorbed by the elastic member.

Therefore, there is an effect that the member having the plane bearing device interposed therebetween can be moved with an extremely small external force compared to the conventional method. Furthermore, if this plane bearing device is installed in a robot hand as described above, a workpiece can be decentered by a small external force. As a result, delicate robot movements can be performed, and the effect of efficient workpiece operation can also be expected.
Moreover, since the plurality of elastic members are directly held by the through holes provided in one flat plate, the number of parts can be suppressed from increasing.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the main parts of a robot hand in which a plane bearing device according to the present invention is installed, and Fig. 2 is a plan view and b an enlarged cross section showing an embodiment of the plane bearing device according to the present invention. 3A and 3B are a plan view and a cross-sectional view, respectively, showing another embodiment. 1...Holder, 3...Eccentricity absorbing member, 6...
Regulating tube, 8... Deviation angle absorbing member, 10... Plane bearing device, 11... Steel ball, 12... Sponge, 17
...A spiral spring.

Claims (1)

[Scope of utility model registration request] At least three or more through holes are provided in one flat plate interposed between two members having parallel planes, each of which holds a steel ball and has an elastic member that is elastically deformed by the rolling movement of the steel ball. The flat plate and the elastic member are formed to be thinner than the diameter of the steel ball, and the flat plate is held by one of the two members with a gap formed between the two members. Bearing device.