What is claimed is:
1. A toroidal continuously variable transmission comprising:
an input disk and an output disk disposed co-axially in an opposed orientation,
a power roller which is sandwiched in order to transmit drive force between the input and output disks, and
a trunnion which supports the power roller rotatively on a pivot shaft, wherein
the power roller comprises an inner roller making frictional contact between the input and output disks and an outer roller supporting a contact load input from the input and output disks to the inner roller through a ball bearing, and an inner radial hole to support the pivot shaft is formed on a rotational center of the inner roller, the inner radial hole opens toward the outer roller and is covered by a bottom part on a side faced to the input and output disks.
2. The toroidal continuously variable transmission as defined by claim 1, wherein a point of contact between an orbit of the inner roller and the ball bearing diverges from the rotational center of the power roller and a point of contact between an orbit of the outer roller and the ball bearing converges towards the central axis of the power roller, the line of application of a load with respect to a ball bearing is inclined with respect to a rotational center of the power roller.
3. The toroidal continuously variable transmission as defined in claim 1, wherein a roller bearing is provided between an inner radial hole of the inner roller and the pivot shaft, and lubrication oil is supplied to the roller bearing from a lubrication oil passage pierced in the axial direction on an inner part of the pivot shaft.
4. The toroidal continuously variable transmission as defined in claim 3, wherein a lubrication hole piercing the bottom part of the inner radial hole is provided, and the lubrication oil is supplied to respect to the moving faces of the input and output disks from the lubrication hole.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A fluid circulating apparatus for a drill, the drill including a bit, a bit driving means that drives the bit to rotate, and a fluid inlet used to supply a coolant to the bit, whereby the drill cuts and drills an object to be drilled by rotating the bit while supplying the coolant to the bit,
wherein the fluid circulating apparatus for a drill comprises:
a suspension collecting means that collects a suspension derived from the coolant mixed with chippings through cutting and drilling operations;
a suspension filtering means that filters off the chippings included in the suspension, thereby making the suspension back into the coolant to be stored in a reservoir; and
a coolant supplying means that supplies the coolant obtained by the suspension filtering means and stored in the reservoir to the bit, and
wherein the suspension collecting means includes a vacuum pump used to collect the suspension through a discharge channel from a water receiving pad so provided as to surround a point to be drilled, the vacuum pump changing a pressure in the reservoir to subatmospheric pressure.
2. A fluid circulating apparatus for a drill according to claim 1, further comprising a convection prevention cover between the vacuum pump and a water surface in the reservoir.
3. A fluid circulating apparatus for a drill according to claim 2, wherein the convection prevention cover is disposed in a position where the convection prevention cover may be kept in contact with the water surface in the reservoir.
4. A fluid circulating apparatus for a drill according to claim 1, wherein the coolant supplying means includes a pump provided in the reservoir to supply the coolant stored in the reservoir to the bit.
5. A fluid circulating apparatus for a drill according to claim 4, wherein the pump is provided in a floating state on a fluid surface of the coolant to feed a top layer of the coolant to the bit.
6. A fluid circulating apparatus for a drill according to claim 1, wherein the coolant supplying means includes a grain mixing means that mixes the filtered coolant with grains for grinding a cutting edge of the bit.
7. A fluid circulating apparatus for a drill according to claim 1, wherein the suspension collecting means includes a suspension dispersion jig provided at an end of the discharge channel through which the suspension is collected, and
wherein the suspension dispersion jig includes a cylindrical body part shaped like a cylinder having a bottom end closed, and a branched part that branches out in a predetermined vertical position relative to the closed bottom end of the cylindrical body part, the branched part being shaped like a cylinder having a bottom end closed, an opening through which the suspension is flown out being formed in the branched part.