Patent Description:
<CIT> (see <FIG>) discloses an example of a portable turning machine according to the preamble of claim <NUM>, and specifically it discloses a machine that is attached to a rotor axis of a generator and performs corrective machining of a surface (specifically, a surface that slides against a bearing) of the rotor axis. This portable turning machine includes a first stator section attached on one lengthwise side of the rotor axis, a second stator section attached on the other lengthwise side of the rotor axis, a turning mechanism section that is arranged between the first stator section and the second stator section to be able to turn around the rotor axis, and a motor that turns the turning mechanism section via a gear mechanism. The turning mechanism section includes a first support section that is arranged on one lengthwise side of the rotor axis, a second support section that is arranged on the other lengthwise side of the rotor axis, a plurality of guides that are coupled between the first support section and the second support section, a laterally shifting section that is able to shift along the plurality of guides (i.e., in the lengthwise direction of the rotor axis), a motor that shifts the laterally shifting section in the lengthwise direction of the rotor axis via a transfer mechanism, and a cutting tool that is provided to the laterally shifting section and used for corrective machining of the surface of the rotor axis.

Meanwhile, there are some generators having a rotor axis including a pair of collector rings and a fan that is positioned between the pair of collector rings and has a diameter larger than diameters of the collector rings, for example. Surfaces of the collector rings are pressed against carbon brushes, and so there is a possibility that they experience uneven wear due to long-term use. Accordingly, there is a demand for corrective machining of the surfaces of the collector rings performed during a periodic inspection, for example. In particular, there is a demand for corrective machining of the surfaces of the collector rings performed while the rotor axis of the generator is kept installed in place because taking the rotor axis out of the generator requires time and effort.

As possible configurations of a machine that performs corrective machining of collector rings while a rotor axis of a generator is kept installed in place, there is a configuration by which corrective machining of collector rings is performed with a stationary tool while the rotor axis of the generator is kept turning. However, in this case, corrective machining of the collector rings cannot be performed unless the generator is in a state where it can run during a period of a periodic inspection, for example. That is, the timing for corrective machining of the collector rings is limited, and it is difficult to secure the schedule therefor (several days, for example). Alternatively, there is a possibility that the period of a periodic inspection is prolonged in order to secure the schedule for corrective machining of collector rings, and the return of the generator to its running is delayed.

In view of this, as possible configurations of a machine that performs corrective machining of collector rings while the rotor axis of the generator is kept installed in place, there is a configuration like the one described in <CIT> in which a tool is turned. However, if there is a fan (interfering object) with a diameter larger than the diameters of collector rings (to-be-machined objects) as mentioned above, it is difficult to attach a machine to the rotor axis as in <CIT>. Alternatively, it is difficult to perform corrective machining of both of the collector rings.

The present invention has been made in view of the matters described above, and one of the objects of the present invention is to make it possible to easily perform corrective machining of a to-be-machined object even in a case where there is an interfering object with a diameter larger than a diameter of the to-be-machined object.

In order to achieve the object described above, the present invention suggest the portable turning machine defined in Claim <NUM>. Further advantageous features are set out in Claim <NUM>.

The present invention makes it possible to easily perform corrective machining of a to-be-machined object even in a case where there is an interfering object with a diameter larger than a diameter of the to-be-machined object.

One embodiment according to the present invention is explained by using <FIG>.

<FIG> is a front view representing a structure of a generator that is equipment including to-be-machined objects in the present embodiment. <FIG> is a front view representing a structure of a portable turning machine in the present embodiment (a view as seen in a direction of arrow II in <FIG> is a top view representing the structure of the portable turning machine in the present embodiment (a view as seen in a direction of arrow III in <FIG>). <FIG> is a side view representing the structure of the portable turning machine in the present embodiment (a view as seen in a direction of arrow IV in <FIG>). <FIG> is a side view representing the structure of the portable turning machine in the present embodiment, and illustrates a state where a ring base and a turning ring have been divided.

The equipment in the present embodiment is a generator <NUM> installed on a floor <NUM>. The generator <NUM> includes a rotor axis <NUM> extending in a horizontal direction, a rotor coil etc. (not illustrated) provided to the rotor axis <NUM>, a stator frame <NUM>, and a stator coil etc. (not illustrated) provided to the stator frame <NUM> and arranged on an outer circumference side of the rotor. The rotor axis <NUM> of the generator <NUM> includes a pair of collector rings 4A and 4B and a fan <NUM> that is positioned between the collector rings 4A and 4B and has a diameter larger than diameters of the collector rings 4A and 4B.

A portable turning machine <NUM> in the present embodiment performs corrective machining of the collector rings 4A and 4B (cylindrical to-be-machined objects) while the rotor axis <NUM> of the generator <NUM> is kept installed in place. The portable turning machine <NUM> includes a support <NUM> placed on and fixed to the floor <NUM>, a ring base <NUM> supported by the support <NUM>, a turning ring <NUM> that is turnably supported by the ring base <NUM> and arranged on an outer circumference side of the collector ring 4A or 4B, a motor <NUM> for turning ring that turns the turning ring <NUM>, and a tool <NUM> that is attached to the turning ring <NUM> and is used for performing corrective machining of the collector ring 4A or 4B.

The support <NUM> includes a base plate <NUM> that is placed on the floor <NUM> and fixed thereto by using a plurality of fixing members (not illustrated), a machine bed <NUM> placed above the base plate <NUM>, a leveling mechanism that adjusts a level of the machine bed <NUM> (details thereof are mentioned below), a positioning mechanism that adjusts a position of the machine bed <NUM> (details thereof are mentioned below), and a plurality of clamps <NUM> (four clamps <NUM> in the present embodiment) that fix the machine bed <NUM> to a frame section <NUM> of the base plate <NUM>.

The leveling mechanism has a plurality of screw holes (nine screw holes in the present embodiment) that are formed through the machine bed <NUM> and penetrate the machine bed <NUM> in an upward/downward direction and a plurality of leveling bolts <NUM> (nine leveling bolts <NUM> in the present embodiment) each of which is screwed through one of the plurality of screw holes. Then, lengths of protruding sections of the leveling bolts <NUM> that protrude from a lower surface of the machine bed <NUM> and abut on a top surface of the base plate <NUM> can be adjusted. Thereby, the level of the machine bed <NUM> can be adjusted such that a turning center line L2 of the turning ring <NUM> is at the same level as a turning center line L1 of the rotor axis <NUM> of the generator <NUM>.

The positioning mechanism has a plurality of first screw holes (two first screw holes in the present embodiment) that are formed on a front side (a lower side in <FIG>) of the frame section <NUM> of the base plate <NUM> and penetrate the frame section <NUM> in a forward/backward direction (an upward/downward direction in <FIG>), a plurality of front centering bolts 22A (two front centering bolts 22A in the present embodiment) each of which is screwed through one of the plurality of first screw holes, a plurality of second screw holes (two second screw holes in the present embodiment) that are formed on a rear side (an upper side in <FIG>) of the frame section <NUM> of the base plate <NUM> and penetrate the frame section <NUM> in the forward/backward direction, and a plurality of rear centering bolts 22B (two rear centering bolts 22B in the present embodiment) each of which is screwed through one of the plurality of second screw holes.

In addition, the positioning mechanism has a plurality of third screw holes (two third screw holes in the present embodiment) that are formed on a right side (a right side in <FIG>) of the frame section <NUM> of the base plate <NUM> and penetrate the frame section <NUM> in a leftward/rightward direction (a leftward/rightward direction in <FIG>), a plurality of right centering bolts 22C (two right centering bolts 22C in the present embodiment) each of which is screwed through one of the plurality of third screw holes, a plurality of fourth screw holes (two fourth screw holes in the present embodiment) that are formed on the right side of the frame section <NUM> of the base plate <NUM> and penetrate the frame section <NUM> in the leftward/rightward direction, a plurality of fifth screw holes (two fifth screw holes in the present embodiment) each of which corresponds to one of the plurality of fourth screw holes and is formed on a right portion of the machine bed <NUM>, and a plurality of right pull bolts <NUM> (two right pull bolts <NUM> in the present embodiment) each of which is screwed through both one of the fourth screw holes and one of the fifth screw holes. Note that a reason why not left centering bolts but the right pull bolts <NUM> are provided is for avoiding interference with the stator frame <NUM> of the generator <NUM> (see <FIG>).

Then, the front centering bolts 22A protrude from the frame section <NUM> of the base plate <NUM> to press a front surface of the machine bed <NUM>, the rear centering bolts 22B protrude from the frame section <NUM> of the base plate <NUM> to press a rear surface of the machine bed <NUM>, the right centering bolts 22C protrude from the frame section <NUM> of the base plate <NUM> to press a right surface of the machine bed <NUM>, or the right pull bolts <NUM> pull the right portion of the machine bed <NUM>. Thereby, the position of the machine bed <NUM> can be adjusted such that the turning center line L2 of the turning ring <NUM> becomes parallel to the turning center line L1 of the rotor axis <NUM> of the generator <NUM>.

The support <NUM> further includes a saddle <NUM> that is provided above the machine bed <NUM> and supports the ring base <NUM>, a shifting mechanism 25A that shifts the saddle <NUM> in the forward/backward direction relative to the machine bed <NUM>, and a shifting mechanism 25B that shifts the ring base <NUM> in the leftward/rightward direction relative to the saddle <NUM>.

A plurality of protruding sections <NUM> (three protruding sections <NUM> in the present embodiment) extending in the forward/backward direction are formed above the machine bed <NUM>, and a plurality of groove sections <NUM> (three groove sections <NUM> in the present embodiment) each corresponding to one of the plurality of protruding sections <NUM> are formed below the saddle <NUM>. Thereby, the saddle <NUM> is able to shift in the forward/backward direction relative to the machine bed <NUM>. The shifting mechanism 25A has a ball screw 28A extending in the forward/backward direction and a servomotor 29A that turns the ball screw 28A. The ball screw 28A includes a screw axis and a nut through which the screw axis is screwed via a plurality of balls, and the nut is coupled with the saddle <NUM>. Then, the saddle <NUM> shifts in the forward/backward direction along with the turning of the ball screw 28A. As a result, the ring base <NUM> shifts in the forward/backward direction (i.e., in a horizontal direction orthogonal to the turning center line L2 of the turning ring <NUM>).

The saddle <NUM> is provided with a plurality of rails <NUM> (three rails <NUM> in the present embodiment) extending in the leftward/rightward direction and a plurality of sliders <NUM> (three sliders <NUM> in the present embodiment) each of which is able to shift along one of the plurality of rails <NUM>, and the plurality of sliders <NUM> are coupled with the ring base <NUM>. Thereby, the ring base <NUM> is able to shift in the leftward/rightward direction relative to the saddle <NUM>. The shifting mechanism 25B has a ball screw 28B extending in the leftward/rightward direction and a motor 29B that turns the ball screw 28B. The ball screw 28B includes a screw axis and a nut through which the screw axis is screwed via a plurality of balls, and the nut is coupled with the ring base <NUM>. Then, the ring base <NUM> shifts in the leftward/rightward direction (i.e., in a horizontal direction parallel to the turning center line L2 of the turning ring <NUM>) along with the turning of the ball screw 28B.

The turning ring <NUM> is turnably supported by a plurality of bearings <NUM> (eight bearings <NUM> in the present embodiment) that are arranged spaced apart in a circumferential direction of the ring base <NUM>. The motor <NUM> for turning ring turns the turning ring <NUM> via a gear mechanism which is not illustrated. The turning ring <NUM> is provided with a tool holder <NUM> to which the tool <NUM> is able to be attached detachably. The tool holder <NUM> is able to adjust a position of the tool <NUM> in a radial direction of the turning ring <NUM>. The tool <NUM> is, for example, a cutting tool, a polishing tool, a vanishing tool, or the like and is used for performing corrective machining of a surface of the collector ring 4A or 4B.

Here, as one of the most characteristic features of the present embodiment, the ring base <NUM> and the turning ring <NUM> each have a structure that is dividable into a lower portion and an upper portion. Explaining specifically, the ring base <NUM> has a structure that is dividable into a lower dividable type ring base 34A and an upper dividable type ring base 34B along a dividing line that is inclined to the horizontal direction. The lower dividable type ring base 34A is coupled to the plurality of sliders and nuts that are mentioned above. The upper dividable type ring base 34B is coupled to the lower dividable type ring base 34A by using a first coupling bolt which is not illustrated. The turning ring <NUM> has a structure that is dividable into a lower dividable type turning ring 35A and an upper dividable type turning ring 35B along a dividing line that is the same as that for the ring base <NUM>. The tool holder <NUM> mentioned above is provided to the upper dividable type turning ring 35B. The upper dividable type turning ring 35B is coupled to the lower dividable type turning ring 35A by using a second coupling bolt which is not illustrated.

Next, operation and action/effects of the present embodiment are explained.

The portable turning machine <NUM> performs corrective machining of the collector rings 4A and 4B while the rotor axis <NUM> of the generator <NUM> is kept installed in place. At a preparatory step, the support <NUM> is placed on and fixed to the floor <NUM>. Then, the ring base <NUM>, the turning ring <NUM>, and the like are assembled such that positions of the ring base <NUM> and the turning ring <NUM> align with a position of the collector ring 4A. Then, the level and the position of the machine bed <NUM> included in the support <NUM> are adjusted, and the level and the position of the turning center line L2 of the turning ring <NUM> are adjusted. Then, the turning ring <NUM> is turned to perform corrective machining of the collector ring 4A.

After completion of the corrective machining of the collector ring 4A, a known stopper mechanism is used to stop the turning of the turning ring <NUM> such that the dividing line of the turning ring <NUM> and the dividing line of the ring base <NUM> match. Then, the lower dividable type ring base 34A and the lower dividable type turning ring 35A are coupled by using a first coupling jig which is not illustrated, and the upper dividable type ring base 34B and the upper dividable type turning ring 35B are coupled by using a second coupling jig which is not illustrated. Then, the first and second coupling bolts are removed to separate the lower dividable type ring base 34A and the upper dividable type ring base 34B, and separate the lower dividable type turning ring 35A and the upper dividable type turning ring 35B. Then, the upper dividable type ring base 34B and the upper dividable type turning ring 35B are hung up, and then the lower dividable type ring base 34A and the lower dividable type turning ring 35A are shifted to align with a position of the collector ring 4B.

At this time, in a case where an outer diameter dimension of the fan <NUM> is smaller than an internal diameter dimension of the lower dividable type turning ring 35A as illustrated in <FIG> and <FIG>, the lower dividable type ring base 34A and the lower dividable type turning ring 35A have to be shifted only leftward. Interference between the upper dividable type turning ring 35B and the tool holder <NUM>, and the fan <NUM> can be avoided because the upper dividable type ring base 34B and the upper dividable type turning ring 35B are separated. On the other hand, in a case where the outer diameter dimension of the fan <NUM> is slightly larger than the internal diameter dimension of the lower dividable type turning ring 35A, the lower dividable type ring base 34A and the lower dividable type turning ring 35A have only to be shifted forward, leftward, and backward in this order. Interference between the lower dividable type ring base 34A and the lower dividable type turning ring 35A, and the collector ring 4A can be avoided easily because the dividing lines of the ring base <NUM> and the turning ring <NUM> are inclined to the horizontal direction.

After positions of the lower dividable type ring base 34A and the lower dividable type turning ring 35A get aligned with the position of the collector ring 4B, the upper dividable type ring base 34B and the upper dividable type turning ring 35B are hung down, the lower dividable type ring base 34A and the upper dividable type ring base 34B are coupled by using the first coupling bolt, and the lower dividable type turning ring 35A and the upper dividable type turning ring 35B are coupled by using the second coupling bolt. Then, the first and second coupling jigs are removed to separate the lower dividable type ring base 34A and the lower dividable type turning ring 35A, and separate the upper dividable type ring base 34B and the upper dividable type turning ring 35B. Then, the turning ring <NUM> is turned to perform corrective machining of the collector ring 4B.

In the manner mentioned above, in the present embodiment, corrective machining of the collector rings 4A and 4B can be performed easily even in a case where there is the fan <NUM> with a diameter larger than the diameters of the collector rings 4A and 4B.

Note that although the support <NUM> has the leveling mechanism that adjusts the level of the machine bed <NUM> in the example case explained in the one embodiment described above, this is not the sole example, and a height-raising mechanism that raises the level of the machine bed <NUM> may further be attached. Such a modification example is explained by using <FIG> is a front view representing a structure of the portable turning machine in the present modification example. Note that portions in the present modification example that are equivalent to their counterparts in the one embodiment described above are given the same reference symbols, and explanations thereof are omitted as appropriate.

The height-raising mechanism in the present modification example has a plurality of spacer blocks <NUM> for mechanical bed (nine spacer blocks <NUM> for mechanical bed in the present modification example), a plurality of spacer blocks <NUM> for leveling bolt (six spacer blocks <NUM> for leveling bolt in the present modification example), and a plurality of spacer blocks <NUM> for clamp (four spacer blocks <NUM> for clamp in the present modification example). Each of the nine spacer blocks <NUM> for mechanical bed is attached at a position that is between the top surface of the base plate <NUM> and the lower surface of the machine bed <NUM> and corresponds to one of the nine leveling bolts <NUM>. Each of four spacer blocks <NUM> for leveling bolt is attached at a position that is on an upper side of the frame section <NUM> of the base plate <NUM> and corresponds to one of the two front centering bolts 22A and two rear centering bolts 22B. Each of two spacer blocks <NUM> for leveling bolt is attached at a position that is on the upper side of the frame section <NUM> of the base plate <NUM> and corresponds to one of the two sets of the right centering bolt 22C and the right pull bolt <NUM>. A screw hole through which a front centering bolt 22A, a rear centering bolt 22B, a right centering bolt 22C, or a right pull bolt <NUM> is screwed is formed through each spacer block <NUM> for leveling bolt. The four spacer blocks <NUM> for clamp are attached at positions that are on the upper side of the frame section <NUM> of the base plate <NUM> and correspond to the clamps <NUM>.

According to the present modification example, it is possible to cope with various heights of the rotor axis <NUM> by changing heights of the spacer blocks <NUM> for mechanical bed, the spacer blocks <NUM> for leveling bolt, and the spacer blocks <NUM> for clamp.

Claim 1:
A portable turning machine (<NUM>) comprising:
a support (<NUM>) placed on and fixed to a floor (<NUM>);
a ring base (<NUM>) supported by the support;
a turning ring (<NUM>) that is turnably supported by the ring base and arranged on an outer circumference side of a cylindrical or columnar to-be-machined object (4A; 4B);
a motor (<NUM>) for the turning ring that is adapted to turn the turning ring; and
a tool (<NUM>) that is attached to the turning ring and is adapted to be used for performing corrective machining of the to-be-machined object, wherein
the ring base and the turning ring each have a structure that is dividable into a lower portion (34A; 35A) and an upper portion (34B; 35B),
characterised in that
the support has
a first shifting mechanism (25A) adapted to shift the ring base in a first horizontal direction orthogonal to a turning center line of the turning ring, and
a second shifting mechanism (25B) adapted to shift the ring base in a second horizontal direction parallel to the turning center line of the turning ring.