Inspection apparatus for inspecting performance of structure by inserting measuring element through gap formed therein

The inspection apparatus for inspecting performance of a structure such as stator windings of an electric rotating machine of the invention comprises a probe including a measuring element, an arm unit and a cylinder face circumferential moving apparatus. The arm unit has an arm link section supporting the probe (mainly comprising a leading end link assembly and an arm posture keeping mechanism), an arm housing section (mainly comprising a guide rail) regarding driving of this arm link section, and an arm driving mechanism. The arm driving mechanism causes the leading end link assembly to project from the guide rail at an angle toward a measuring position side of the stator windings relative to the axial direction of the rotor unit, while causing the arm link section to travel along the guide rail. The arm posture keeping mechanism is provided with a link wire and a spring, and maintains a straight arm posture of the leading end link assembly after projection from the guide rail.

BACKGROUND OF THE INVENTION 
The present invention relates to an inspection apparatus using a measuring 
element such as an inspection apparatus of a stator winding of an electric 
rotating machine, an arm unit and a cylinder face circumferential moving 
apparatus. More particularly, the present invention relates to an arm 
construction and a traveling mechanism suitable for an inspection 
apparatus for measuring electrostatic capacity of a stator winding in a 
state in which a rotor is inserted. 
There is known in general a type of electric rotating machine having a 
water-cooled stator winding. Examples of this type are illustrated in 
FIGS. 29 to 31. 
The electric rotating machine shown in FIG. 29 comprises a stator unit 120 
comprising a stator 104 formed by inserting and fixing a stator winding 
(an upper stator winding 103a and a lower stator winding 103b in FIG. 29) 
in a stator iron core 102 attached to a stator frame 101, and a rotor unit 
130 arranged oppositely to this stator unit 120 in a non-contact manner, 
the rotor unit having a rotor 121, protecting ring 122 and a rotation 
shaft 123. 
Among these components, the stator winding 103 is formed, as shown in FIGS. 
30 and 31, by gathering a plurality of strands 105, covering the outside 
thereof with an insulating layer 106 such as an insulating tape or an 
epoxy resin, and attaching clips 107 to each end of the individual strands 
105. Each of the strands 105 is provided with a hollow hole 108 through 
which cooling water can flow. These hollow holes 108 communicate to an 
insulating connection pipe (not shown) and a cooling water duct 110 
outside the stator frame 101 through a water inlet port or a water inlet 
port 109 of the clip 107. Cooling water from the cooling water duct 110 is 
therefore supplied through the insulating connection pipe and the water 
inlet port 109 of the clip 107 to the hollow hole 108, and cooling water 
is discharged through the water inlet port 109 of the clip 107 to the 
cooling water duct 110. 
The individual strands 105, the clip 107 and the insulating connection pipe 
thus forming a path for cooling water are connected by brazing, and the 
outside of braze-connected portions is covered with an insulating layer 
106 in a manner as described above. The braze-connected portions covered 
with the insulating layer 106 is subjected to various leakage tests after 
a strict quality control with a view to preventing leakage of cooling 
water and thus to assuring reliability. To avoid such inconveniences as 
partial peeling of the braze-connected portions or pit corrosion caused by 
vibration, heat cycles and corrosion through service for many years, a 
coil pressurizing test or a vacuum drop test is usually applied during a 
periodical inspection to check a change in pressure and thus to confirm 
the non-leakage state. 
However, when cooling water leaks from the connecting portion between the 
strands 105 and the clip 107, cooling water permeates through the 
insulating layer 106 at the portion covered with an insulating tape by 
capillary action, and particularly when cooling water permeation reaches 
the stator iron core 102, an inconvenience known as a ground-fault may 
occur between the stator winding 103 and the ground. It is therefore 
believed to be important to pay sufficient attention to permeation of 
cooling water into the insulating layer 106 and check it up as early as 
possible. 
As a method for such a checkup, there is proposed a method of inspection, 
paying attention to the difference in specific inductive capacity between 
the insulating layer 106 and cooling water, which comprises determining a 
corroded stator winding resulting from absorption of water by the 
insulating layer caused by cooling water leakage by measuring 
electrostatic capacity through application of a measuring element to 
measuring positions P and P (see FIG. 29) of the stator winding. 
In the checkup method of determining the corroded stator winding resulting 
from absorption of water by the insulating layer caused by cooling water 
leakage, however, the measuring position of the stator winding to which 
the measuring element is applied is located at a depth in the electric 
rotating machine or the human hand is unreachable in the state as it is. 
It is therefore necessary to perform an inspection by pulling out the 
rotor unit from the stator unit. 
The operation of thus pulling out the rotor unit requires much labor for 
dismantling, takes much time, and is not always efficient. Furthermore, 
because inspection of the stator winding including the operation for 
pulling out the rotor unit is carried out by stopping the electric 
rotating machine, a longer inspection period leads to a higher cost. 
The inspection carried out after removal of the rotor unit also requires 
direct use of human power in pressing operation of the measuring element, 
and is not therefore always efficient. 
Because, for example, the measuring element has usually a rectangular 
shape, there may be a change in the effective area of the measuring 
element, depending upon the direction of pressing, resulting in easy 
occurrence of fluctuations of measured data. In order to obtain 
satisfactory measured data, it is necessary to press the measuring element 
while causing the same to follow the curved and other surfaces of the 
stator winding, and it is difficult to carry out this pressing operation 
within a limited space. 
SUMMARY OF THE INVENTION 
Accordingly, the present invention is to solve these conventional problems, 
and has an object to relatively easily and accurately carry out an 
inspection of the stator winding without pulling out the rotor unit from 
the stator unit, and complete this inspection operation in a short period 
of time. 
Another object of the present invention is to construct and provide at a 
low cost a highly practicable equipment configuration suitable for 
inspection of a stator winding of an electric rotating machine. 
Further another object of the present invention is to carry out relatively 
simply and accurately the pressing operation of the measuring element. 
The above objects can be achieved according to the present invention, in 
one aspect providing by an inspection apparatus for inspecting performance 
of a structure at a measuring position placed therein through a gap formed 
in the structure, said inspection apparatus comprising a measuring element 
for measuring data associated with performance of the structure, an arm 
body for supporting the measuring element, and means for inserting the 
measuring element supported by the arm body through the gap along an arm 
axial direction of the arm body by continuously operation, thereby the 
measuring element being set at the measuring position. 
In preferred embodiments, the arm body is an arm link assembly formed by 
connecting a plurality of links in the arm axial direction. 
The inserting means comprises an arm moving element for causing the arm 
link assembly to travel in the gap and to project at an angle directed 
toward the measuring position relative to the direction of the travel 
while causing the travel of the arm link assembly and an arm posture 
keeping element for keeping a linear arm posture of the arm link assembly 
caused to project by the arm moving element. 
The moving element comprises a guide for guiding the travel and projection 
of the arm link assembly and a driving mechanism for driving the arm link 
assembly along the guide. The driving mechanism is a sliding mechanism for 
sliding the arm like assembly in the arm axial direction. The sliding 
mechanism is a feed screw mechanism. 
Adjacent two links of the links are rockable between an angle depending 
upon the linear arm posture and a prescribed angle limited toward one side 
of the linear arm posture mutually around a connecting center of the other 
link. 
The arm posture keeping element includes a cable-like member being secured 
to a leading end side link of the links through one side of each of 
connecting shafts of the links at one end of the cable-like member, an 
elastic member connected to the other end of the cable-like member, the 
elastic member being secured to a trailing end side link of the links. 
The arm posture keeping element includes a leaf spring being secured to a 
leading end side link at one end of the leaf spring and being secured to a 
trailing end side link of the links through one side of each of connecting 
shafts thereof at the other end of the leaf spring. 
The arm posture keeping element includes a plurality of pulleys rotatably 
connected to each of the links so as to constrain a rotation angle of a 
trailing end side pulley of the pulleys and limit a rotation angle of a 
leading end side pulley of the pulleys to a prescribed angle relative to 
the leading end side link and a plurality of belts connecting mutually 
adjacent two pulleys of the pulleys. 
Each of the links form a frame. 
The structure is an electric rotating machine comprising a rotor body of 
cylindrical structure and a stator body covering an outer peripheral 
portion of the rotor body in a non-contact fashion, the stator body 
including a stator winding formed with an insulation and arranged radially 
outward of the rotor body and a stator core which supports the stator 
winding, the gap being located between the rotor body and stator body, 
said measuring position being placed on the stator winding, said arm body 
being attached to the rotor body so that the arm axial direction becomes 
an axial direction of the rotor body, and said measuring element being an 
element for measuring electrostatic capacity of the stator winding as the 
data. 
An inspection apparatus may further comprise a cylinder face 
circumferential moving apparatus for causing the measuring element 
supported by the arm body to freely travel in a circumferential direction 
of the rotor body. 
The cylinder face circumferential moving apparatus comprises a belt member 
having a toothed belt attachable in the circumferential direction of the 
rotor body, a pulley engaging with the toothed belt, a drive which 
rotatably drives the pulley, and a cable-like member attachable in the 
circumferential direction, the cable-like member being detachably wound on 
the rotor body so as to press the drive against the belt member and the 
arm body is attached to the drive. The belt member has a belt and a hoist 
capable of hoisting the belt, the belt being attached to both ends of the 
toothed belt and the belt being hoisted by the hoist, thereby the toothed 
belt hoisted and secured onto the rotor. The belt is attached to one end 
of the cable-like member, said hoist being attached to the other end of 
the cable-like member. The cable-like member is provided with a tension 
regulator. 
The cylinder face circumferentiial moving apparatus comprise a roller chain 
being detachably wound the rotor along the circumferential direction of 
the rotor body, a sprocket engaging with the roller chain, and a drive for 
rotatably driving the sprockets engaging with the roller chain, the drive 
being arranged on the roller chain, the cable-like member being wound on 
the rotor body so as to press the drive against the roller chain, the arm 
body being attached to the drive. 
An inspection apparatus may further comprise means for setting origins for 
the axial position of the rotor body in the arm body and for the 
circumferential position of the rotor body in the cylinder face 
circumferential moving apparatus. 
An inspection apparatus may further comprise a probe body having a base to 
be attached to the arm body, an expansible bellow attached to at least one 
side of the base and means for supplying and discharging air into and from 
the expansible bellow, and the measuring element being attached to the 
expansible bellow. 
The arm body is a rod supporting the probe body. 
The inserting means includes a traveling system for causing the measuring 
element to travel in the axial direction of the rotor body and positioning 
the measuring element at the measuring position of the stator winding, 
said traveling system including a driving mechanism having a servo motor 
and control means which conducts so that a winding of the servo motor is 
in a non-excited state during the measurement of the electrostatic 
capacity. The control means is provided with means for conducting control 
so that a rotation angle of the servo motor is in a non-detection state 
during the measurement of the electrostatic capacity. 
The arm posture keeping element includes an element for keeping a 
prescribed angle of a base posture after the projection of the measuring 
element relative to the arm posture of the arm link assembly. 
The structure is an electric rotating machine comprising a rotor body of 
cylindrical structure and a stator body covering an outer peripheral 
portion of the rotor body in a non-contact fashion, the stator body 
including a stator winding formed with an insulation and arranged radially 
outward of the rotor body and a stator core which supports the stator 
winding, the gap being located between the rotor body and stator body, 
said measuring position being placed on the stator winding, said arm like 
assembly being attached to the rotor body so that the arm axial direction 
becomes an axial direction of the rotor body, and said measuring element 
being a element for measuring electrostatic capacity of the stator winding 
as the data. 
The arm moving means includes means for detecting data associated with a 
winding width in the radial direction of the stator winding when the arm 
link assembly travels and projects under the action of the arm moving 
element and means for specifying the measuring position of the stator 
winding based on the detected data. 
The arm moving element includes means for positioning the measuring element 
at a desired position in the radial direction of the stator winding. 
The cylinder face circumferential moving apparatus includes means for 
determining a insertion position of the measuring element in the 
circumferential direction of the rotor body. 
The cylinder face circumferential moving apparatus includes means for 
limiting circumferential travel of the measuring element supported by the 
arm body on the basis of the state of arrangement of the measuring element 
relative to the arm link assembly. 
The bellow is a plurality of bellows and said probe body has a cover 
covering the measuring element upon contraction of the bellows. 
The measuring element is made of a copper foil being applied to one surface 
of a cushion material, the other surface of the cushion material is 
covered with a copper foil for grounding, and said probe body is attached 
through the copper foil for grounding. 
An inspection apparatus may further comprise means for alternately changing 
each of the measuring elements attached through the expansible bellow to 
both sides of the base. 
The inserting means includes means for causing the probe body supported by 
the rod to freely slide in the axial direction and the radial direction of 
the electric rotating machine, and means for positioning the probe body 
supported by the rod rockably in the circumferential direction of the 
electric rotating machine. 
The rod is a bar rockably supporting the probe body. 
An inspection apparatus may further comprise means for measuring a data in 
a non-contact state with the stator body as an initial value by the 
measuring element. 
An inspection apparatus may further comprise means for discharging charge 
of the measuring element before the measurement of the electrostatic 
capacity. 
The measuring position is selected from an exposed portion extending from 
the iron core end of the stator winding to outside the machine except for 
a portion subjected to a corona preventing treatment of the stator 
winding. 
An inspection apparatus may further comprise means for measuring resistance 
value regarding a contact state of the measuring element with the stator 
winding as data for evaluation of the electrostatic capacity. 
An inspection apparatus may further comprise means for automatically the 
measuring position of the stator winding during the measurement of the 
resistance value. 
The measuring element has a measuring frequency of approximately 1 kHz. 
In the inspection apparatus of this present invention, as described above 
in detail, while causing the arm link assembly to travel in a prescribed 
direction relative to the structure (for example, in the axial direction 
of the rotor unit), the arm link assembly is caused to project at an angle 
toward the measuring position side (for example, the gap of the stator 
windings) relative to this direction. The arm posture of the thus 
projecting arm link assembly is kept linear. Therefore, positioning to a 
prescribed position (for example, the gap of the stator windings) which 
would be unreachable without flexing in the middle, in a limited space of 
service, can be accomplished only by sliding drive of the arm link 
assembly, i.e., by a simple operation of a degree of freedom of 1. 
This effect displays its full merit when the invention is applied in an 
inspection apparatus of stator windings of an electric rotating machine. 
In this case, it is possible to easily and accurately carry out inspection 
of the stator windings without the necessity of removing the rotor unit 
from the stator unit, and complete the inspecting operation in a short 
period of time. It is thus possible to simply achieve an inspection 
apparatus of a high practical merit at the relatively low cost.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Preferred embodiments of the present invention will be described with 
reference to the drawings below. 
FIRST EMBODIMENT 
Now, a first embodiment of the present invention will be described below 
with reference to FIGS. 1 to 10. This embodiment is based on an 
application of the inspection apparatus using a measuring element, the arm 
unit and the cylinder face circumferential moving apparatus of the present 
invention to an inspection apparatus (electrostatic capacity measuring 
apparatus) of a stator winding of an electric rotating machine. As the 
electric rotating machine is almost identical with a conventional one, 
description of an outline thereof is omitted here, the same reference 
numerals being assigned to corresponding components. 
The perspective view of FIG. 1 and the sectional view of FIG. 2 illustrate 
a whole construction of the inspection apparatus of a stator winding of an 
electric rotating machine (hereinafter simply referred to as the 
"inspection apparatus"). 
The inspection apparatus shown in these drawings is to move and position a 
measuring element 1a for measuring electrostatic capacity from a gap 
between a rotor unit 130 and a stator unit 120 to a measuring position P 
of a stator winding 103, and comprises a probe 1 in which the measuring 
element 1a is arranged, an am unit 10 slidably supporting this probe 1, a 
cylinder face circumferential moving apparatus (hereinafter simply 
referred to as the "moving apparatus") 40 rotatably and slidably 
supporting the arm unit 10, and a positional control system 70 for 
positional control of the arm unit 10 and the moving apparatus 40. 
Now, an outline of the probe 1 will be described below with reference to 
the schematic sectional view shown in FIG. 3 and the operational diagram 
shown in FIG. 4, in addition to FIGS. 1 and 2. 
As shown in FIG. 3, the probe 1 has a base 2 forming a body to be attached 
to the arm unit 10. Expansible bellows 3a and 3b are attached to two sides 
with the axis of the base 2 in between, in a direction at right angles to 
the axial direction. An antiskid material 5 is attached to one of the 
sides of the base 2 and the circular-shaped measuring element 1a is 
attached to the other of the sides of the base 2, through cushions 4a and 
4b attached to respective outer plates of the two bellows 3a and 3b. An 
air path 6 communicating spatially to air chambers of the two bellows 3a 
and 3b is provided in the base 2, and this air path 6 is connected to a 
pneumatic circuit (pneumatic source) not shown through an air piping 7 
attached to the base 2. 
During non-measuring time such as upon guiding, for example, to a measuring 
position P (see FIG. 15) of the stator winding 103, the probe 1 houses the 
bellows 3a and 3b in the base 2. During measurement of the stator winding 
103, as shown in FIG. 4B, the probe 1 presses the measuring element 1a 
against the surface (measuring position P) of the stator winding 103 by 
sending air from the pneumatic circuit through the air piping 7 to the air 
path 6 of the base 2, and moving the antiskid material 5 and the measuring 
element 1a in directions opposite to each other through expansion of the 
bellows 3a and 3b. The pressing force of the antiskid material 5 and the 
measuring element 1a is kept constant by adjusting the pneumatic pressure 
of the pneumatic circuit. Upon completion of the measurement in this 
pressing state, the probe 1 houses the bellows 3a and 3b into the base 2, 
as shown in FIG. 4B, by absorbing air by means of the pneumatic circuit in 
the reverse sequent to the above. 
Now, an outline of the arm unit 10 will be described below with reference 
to FIGS. 5 to 7, in addition to FIGS. 1 and 2. 
As shown in FIGS. 1 and 2, the arm unit 10 comprises an arm link section 
(forming an arm link assembly and arm posture keeping means of the present 
invention) 11 to which the probe 1 is attached, an arm housing section 
(forming a guide member of arm traveling means of the present invention) 
12 which slidably houses the arm link section 11 together with the probe 
1, and guides the leading end of the arm link section 11 so that the same 
projects at an angle toward the measuring position P side specified of the 
stator winding 103, and an arm driving mechanism (forming a driving 
mechanism of the arm traveling means of the present invention) 13 which 
sliding-drives the arm link section 11 in the axial direction of the rotor 
unit 130 relative to the arm housing section 12. 
As shown in FIG. 2, the arm link section 11 comprises link assembly 
different for the leading end and the trailing end thereof (hereinafter 
referred to as the "leading end link assembly 11a") and the "trailing end 
link assembly 11b" for convenience sake), and the arm posture keeping 
mechanism (arm shape keeping mechanism) 14 for keeping the arm shape or 
posture of the leading end link assembly 11a from among these assemblies. 
As shown in FIG. 5, the leading end link assembly 11a is provided with two 
short links 15a and 15b having different sizes comprising frame members, 
and is formed by connecting a plurality of these short links alternately 
in an arm shape. Each of the short links 15a and 15b is formed by 
gathering, for example, a plurality of sheet members, i.e., two 
substantially trapezoidal side plates P1, a bottom side plate P2 and a 
front side plate P3 integrally or into a separate frame construction 
(frame member) (FIG. 5 shows an example of integral forming). Connecting 
holes 16 are pierced at prescribed positions in a direction at right 
angles to the arm axial direction on the two side plates P1 and P1. 
The leading end link assembly 11a alternately connects the short links 15a 
and 15b inserting the pins 17 through the connecting holes 16 of the two 
side plates P1 and P1, and rotatably attaching link rollers 18 and 18 to 
the both ends of these pins 17. The leading end link assembly 11a is 
therefore flexural at an angle limited only in a direction to a reference 
direction x at which the bottom side plates P2 and P2 mutually form 
substantially 180.degree. forming almost a straight line toward the 
respective front side plates P3 around the connecting fulcrum O, when 
viewing in a traveling direction limited by the shape and the position of 
the connecting fulcrum O of, for example, the two short links 15a and 15b, 
for each link. 
As shown in FIG. 2, the trailing end assembly 11b is provided with a 
plurality (two in FIG. 2) of long links 19 and 19 connected to the output 
shaft of the arm driving mechanism 13, and formed into an arm shape by 
connecting these long links 19 and 19 through pins 17 and link rollers 18 
as described above. 
As shown in FIG. 5, the arm posture keeping mechanism 14 is provided with a 
link pulley 20 rotatably attached to a prescribed pin 17 (for example, at 
the leading and trailing ends) in the leading end link assembly 11a and 
link wire 21 guided by a pulley 20a at the center of the link pulley 20 
and inserted through the bottom side plate P2 side (the side on which 
flexure of the leading end link assembly 11a is limited), and is secured 
in the trailing end link assembly 11b through a spring 22 in a state in 
which the link wire 21 is guided by the link pulley 20. 
The link roller 20 has, in addition to the pulley 20a at the center 
thereof, pulleys 20b and 20b having a diameter smaller than that of the 
pulley 20a, at both end sides with the center portion in between, and 
these pulleys 20b and 20b guide, within the arm link section 11, cables 23 
and 23 connecting the measuring element 1a and a separate apparatus such 
as an electrostatic capacity measuring instrument (not shown). 
As shown in FIG. 6, the arm housing section 12 has an enclosure 24 
extending in the axial direction, capable of housing the arm link section 
11 and guides the arm link section 11 along guide rails 25 and 25 which is 
slotted on the both opposite side surfaces 24a and 24a of the enclosure 
24. The guide rail 25 has a width equal to or larger than the diameter of 
the link rollers 18 of the leading end link assembly 11a and the trailing 
end link assembly 11b. The traveling direction thereof extends in the 
axial direction of the enclosure 24, and is formed so as to flex at a 
prescribed radius of curvature in a direction at right angles to the axial 
direction on the leading end side thereof. An opening (not shown) is 
provided at the end of the flexing portion of the guide rail, i.e., on the 
leading end side of the enclosure 24, so as to make the leading end arm 
unit 11a formed by attaching the measuring element 1a projectable to 
outside the enclosure 24 through this opening. 
As shown in FIG. 6, the arm driving mechanism 13 comprises a feed screw 27 
for driving the arm arranged in parallel with the traveling direction of 
the guide rail 25, a feed screw nut for arm driving slidably connected to 
this feed screw 27, and an arm motor 29 driving the feed screw 27 such as 
a servo motor connected to the trailing end of the feed screw 27. The feed 
screw 27 is rotatably attached to a bearing section outside the enclosure 
24, and the feed screw nut 28 is connected to the long link 19 at the rear 
end of the trailing end link assembly 11b. The arm driving mechanism 13 
causes the arm link section 11 to travel along the guide rail 25 (in the 
direction E in FIG. 6) by causing the feed screw nut 28 to slide in the 
axial direction while rotating the feed screw 27 through driving of the 
arm motor 29. 
As shown in FIG. 2, a spare arm traveling apparatus 30 is provided in this 
arm driving mechanism 13. This spare traveling apparatus 30 comprises a 
spare arm motor 32 such as a servo motor connected to the feed screw 27 
through an interlock 31, and a coupling section 33 connecting the feed 
screw 27 and the arm motor 29 with a shaft coupling. The spare arm motor 
32 rotates only passively during service of the arm motor 29, not 
participating in the drive of the arm link section 11. When the arm motor 
29 is not serviceable by a failure or the like, it actively drives to 
operate the feed screw 27 through the interlock 31. The coupling section 
33 is exposed to permit manual adjustment. When the both motors 29 and 30 
are in failure, the arm link section 11 is made manually movable by 
directly making manual adjustment. The arm driving mechanism 13 is 
provided with a vertical guide door 34 capable of opening/closing on the 
leading end side of the enclosure 24, and a sliding mechanism 36 connected 
to this vertical guide door 34 through a door operating wire 35. When the 
leading end arm unit 11b projects from inside the arm housing section 12, 
the vertical guide door 34 is opened to an angle on the extension of the 
flexing portion of the guide rail 25, and when the leading end arm unit 
11b is housed, it is closed under the action of the force from the sliding 
mechanism 36 through the door operating wire 35 (in direction D in FIG. 
6). 
The sliding mechanism 36 comprises a rod-like rail 38 formed on an outside 
surface of the enclosure 24 in parallel with the axial direction of the 
feed screw 27 for a prescribed distance and formed by fitting a locking 
spring 38a for the door operating wire 35 in the axial direction thereof 
and a wire slide (body) 37 slidable along this rail 38, and forms this 
wire slide 37 into a body capable of coming into contact with the trailing 
end of a dog 28a of the feed screw nut 28. 
The sliding mechanism 36 causes the wire slide 37 to slide for a prescribed 
distance toward the leading end side under the action of tensile force 
acting toward the leading end side of the door operating wire 35 along 
with the opening action of the vertical guide door 34 upon projection of 
the leading end arm unit 11b. During this sliding, the reaction force of 
the locking spring 38a received by the wire slide 37 pulls the door 
operating wire 35 without loosening toward the trailing end side. Upon 
housing the leading end arm unit 11b, the sliding mechanism 36 feeds the 
wire slide 37 by sliding to the trailing end side together with the feed 
screw nut 28 in a state caught by the dog 28a of the screw nut 28, and 
closes the door by pulling the door operating wire 35 toward the trailing 
end side. 
Now, operation of the above-mentioned arm unit 10 will be described below 
with reference to FIGS. 7A to 7C. 
As shown in FIG. 7A, the arm link section 11 attached with the probe 1 is 
housed in the arm housing section 12. Assume that the arm driving 
mechanism 13 is started in this state. Upon starting, the arm motor 29 
operates, and the power thereof causes the feed screw 27 to rotate to 
cause parallel travel of the feed screw nut 28 toward the leading end 
side, whereby the rearmost long link 19 of the trailing end arm unit 11b 
connected to the feed screw nut 28 is moved toward the leading end side. 
At this point, the direction of travel of the link roller 18 is 
constrained by the guide rail 25. The leading end arm unit 11a is thus 
caused to travel in parallel toward the leading end side in the traveling 
direction of the guide rail 25 together with the probe 1. 
Then, as shown in FIG. 7B, when the leading end arm unit 11 reaches the 
flexing portion of the guide rail 25, the top short link 15 and subsequent 
ones are sequentially guided from horizontal to vertical directions. 
Then, as shown in FIG. 7C, the leading end arm units 11a project in the 
direction of extension of the guide rail 25, i.e., to outside the 
enclosure 24, while changing the direction to vertical, sequentially from 
the short link 15 at the top. At this point, the path distance of the 
leading end arm unit 11a increases by the distance of curved portion 
resulting from the radius of curvature of the guide rail 25. The spring 22 
of the arm posture keeping mechanism 14 therefore extends, and the 
reaction force of the spring 22 pulls the link wire 21 toward the trailing 
end side. As a result of this pulling force of the link wire 21, the short 
links 15a and 15b in the projecting state receive the force on the side on 
which flexure is limited (bottom plate side), and the posture of the 
leading end arm unit 11a after projection is maintained so that the arm 
shape is kept straight. 
Now, an outline of the moving apparatus 40 will be described below with 
reference to FIGS. 8 to 10, in addition to FIGS. 1 and 2. 
As shown in FIG. 1, the moving apparatus 40 is provided with a support 41 
adjustably attached to the periphery (cylinder face) of the rotor unit 
130, and a moving member 42 which travels around the rotor unit 130 
relative to the support 41. The foregoing arm unit 10 is attached as a 
separate unit to the moving member 42. 
The support 41 has, as shown in FIG. 8, a track belt section 42a which 
determines a traveling locus of the moving member 42, and a pressing wire 
43 which presses and support appropriately the moving member 42 against 
the track belt section 42a. 
The track belt section 42a has a wide toothed belt 44. The toothed belt 44 
is installed around the rotor unit 130 by providing track belt end fixing 
sections (hereinafter simply referred to as the "fixing sections") 45 and 
45 at the both ends, respectively, of the toothed belt 44, attaching 
hoisting belts 46 and 46 for fixing the track belt to the fixing sections 
45 and 45, securing a ratchet 47 to one of the hoisting belts 46 and 46, 
and hoisting up the other of the hoisting belts 46 and 46 with this 
ratchet 47. Installing position adjusting scales 48 and 48 are attached to 
the fixing sections 45 and 45. 
The pressing wire section 43 is provided with a pressing wire 50 to be 
inserted into wire guides (holes) 49 and 49 provided in the fixing 
sections 45 and 45, and a tension regulator (tension controller) 51 to be 
inserted in the middle of the pressing wire 50. The pressing wire 50 is 
arranged around the track belt section 42a through the wire guides 49 and 
49 by providing a hoisting belt 52 for securing the pressing wire onto one 
of the both ends of the pressing wire 50, providing a ratchet 53 on the 
other, and releasably connecting the hoisting belt 52 to the ratchet 53. 
The tension regulator 51 is provided, as shown in FIG. 9, with a cylinder 
55 having a piston 54, and a frame 56 tiltably (head-movably) supporting 
the cylinder 55 around a rotation fulcrum 01, and secures the hoisting 
belt 52 on the bottom side of the cylinder 55 and on the leading end side 
of the piston 54, adjusts the horizontal travel of the pressing wire 50 by 
the operation in the stroke direction (see direction G in FIG. 9) caused 
by a compression spring (not shown) of the piston 54 relative to the 
cylinder 55, and adjusts the vertical travel of the pressing wire 50 
through tilting motion (see direction F in FIG. 8) of the cylinder 55 
relative to the frame 56. 
As shown in FIGS. 1 and 10, the moving member 42 has, for example, a 
rectangular body 57. Wheel shafts 59 and 60 are provided at two front and 
rear positions of the body 57, and tire pulleys 59a and 60a engaging with 
teeth of the toothed belt 44 are provided on the both end sides of the 
wheel shafts 59 and 60. A transmission pulley 59b and a circumferential 
motor 62 such as a servo motor via a reducer 61 are connected to the 
outside of the tire pulley 59a, and a phase regulator 63 is connected to 
the outside of the other tire pulley 60a through a transmission pulley 
60b. These transmission pulleys 60b and 59b are mutually connected with a 
transmission belt 64. Wire pulleys 65 and 65 for passage of the pressing 
wire 50 and wire guides 66 and 66 are pressed against the top of this 
moving member 42 at two positions, and a wire guide 67 is provided on the 
pressing wire 50 at an appropriate position (reference numeral 77 in FIG. 
10 represents a contact sensor). 
Now, an installation procedure and operations of the above-mentioned moving 
apparatus 40 will be described below. 
First, upon installing the moving apparatus 40, the toothed belt 44 is 
mounted on a cylinder face of the rotor unit 130 (protecting ring 122). 
Then, while aligning the ends of the installing position adjusting scales 
48 and 48 with the end face in the axial direction of the rotor unit 130, 
the toothed belt 44 is arranged horizontally to this end face. In this 
state, the hoisting belt 46 is caused to rotate around the rotor unit 130 
by a turn. This is hoisted in a ring shape with the ratchet and the 
toothed belt 44 is secured around the rotor unit 130. 
Upon completion of installation of the toothed belt 44, the moving member 
42 is arranged on the belt 44. At this point, the pressing wire 50 is 
caused to pass through the wire pulleys 65 and 65, and the wire guides 66 
and 66 are locked so as to prevent the pressing wire 50 from coming off. 
In this state, the hoisting belt 52 for securing the pressing wire is 
wound around the rotor unit 130 by a turn, and this is hoisted with the 
ratchet 53 into a ring shape. Upon hoisting, the ratchet 53 is operated 
while confirming the amount of change in stroke of the piston 54 of the 
tension regulator 51, to adjust tension of the pressing wire 50. The 
moving apparatus 40 is movably mounted on the rotor unit 130 of the moving 
member 42, thus completing the installation of the moving apparatus 40. 
Then, upon starting this moving apparatus 40, the motor 62 for the 
circumferential direction operates, and the driving force thereof is 
reduced and transmitted from a transmission pulley 59b through a 
transmission belt 64 to the other transmission pulley 60b. The four tire 
pulleys 59a and 60a rotate, and the moving member 42 travels on the 
toothed belt 44. During this travel, mutual engagement phase of the tire 
pulleys 59a and 60a with the toothed belt 44 is appropriately adjusted by 
means of a phase regulator 63. 
Even when there occurs a change in the length of the pressing wire 50 at 
the end of the toothed belt 44 during travel of the moving member 42, 
tension is appropriately adjusted by means of the amount of contraction of 
the compression spring of the tension regulator 51. Further, even when 
there occurs a change in the height of the pressing wire 50 depending upon 
the position of travel of the moving member 42, it is appropriately 
adjusted by tilting of the cylinder 55 so that the stroke direction of the 
piston 54 and the axial direction of the wire 50 are always located on the 
same straight line, thus avoiding the undesirable force or moment in the 
transverse direction produced in the compression spring or the piston 54. 
Now, an outline of the moving position control system 70 will be described 
below with reference to FIG. 2. 
The moving position control system 70 is provided with an axial positioning 
regulator 71 which causes the arm unit 10 to move by a prescribed distance 
in the axial direction of the rotor unit 120 relative to the moving 
apparatus 40 installed on the rotor unit 130. 
The axial positioning regulator 71 has a linear guide 72 for guiding the 
arm unit arranged in the axial direction of the rotor unit 130 in the 
upper portion of the moving member 42, and causes the arm housing section 
12 to travel along the linear guide 72. For example, a motor 73 for the 
arm housing section such as a servo motor similar to the above-mentioned 
arm moving mechanism 13, a feed screw 74 for moving the arm housing 
section, and a feed screw nut 75 are attached to the bottom side of the 
enclosure 24. In parallel with these components, the feed screw nut 75 is 
secured to the arm unit 10, and the leading end side of the feed screw 74 
is rotatably attached to a bearing section not shown of the moving member 
42. 
A camera 75a and a distance sensor 76 are attached to the leading end side 
of the arm housing section 12 for the moving position control system 70. 
Now, operations of this embodiment as a whole will be described below with 
reference to FIG. 2. 
First, an outline of the stator winding to be measured in this inspection 
apparatus will be described. As shown in FIG. 2, the distance between the 
rotor unit 130 and the stator unit 120 is, for example, as small as 60 mm. 
The stator windings 103a and 103b on the outside diameter side and on the 
inside diameter side of the stator unit 120 are arranged in a direction 
formed by an involute curve curving in mutually opposite directions and so 
as to form a mesh-like crossings. Particularly, the stator winding 103a on 
the outside diameter side is arranged at a position, for example, about 
300 mm apart from the surface of the protecting ring 122 of the rotor unit 
130. The measuring element 1a should be pressed from such a gap between 
the stator windings 130. 
In the inspection apparatus of this embodiment, therefore, the measuring 
element 1a is guided to the measuring position P of the stator winding 103 
while avoiding the above mesh portion. There is therefore tried an 
operation in which it moves in the axial direction through a narrow gap of 
about 60 mm and then rises up vertically by about 300 mm (see FIG. 2). 
The moving apparatus 40 is first installed on the rotor unit 130 
(protecting ring 122) in the foregoing steps, and It is caused to travel 
along the circumferential direction (see direction C in FIG. 1) of the 
rotor unit 130 into the gap between the stator winding 103 and the rotor 
unit 130 specified as the first measuring position P. 
Then, the motor 73 for the arm housing section operates by starting up the 
axial positioning regulator 71, and the driving force thereof is 
transmitted to the feed screw 74. The feed screw nut 75 travels in 
parallel, and the arm unit 10 is caused to slide in the axial direction 
(see direction A in the drawing) of the rotor unit 130 relative to the 
moving apparatus 40. The axial position of the probe 1 is thus adjusted to 
the inserting position in the radial direction looking out the measuring 
position P between the stator windings 103. 
Then, as the arm unit 10 executes the above-mentioned arm operations, the 
leading end arm unit 11a rises up at an angle (see B in the drawing) 
toward the measuring position P side of the stator winding 103a while 
maintaining the linear arm posture, and while keeping the linear arm 
posture, the probe 1 is inserted into a slot in the stator winding 103, 
together with the leading end arm unit 11a. 
Then, after the probe 1 reaches the measuring position P of the stator 
winding 103, the measuring element 1a is pressed against the stator 
winding 103 by expanding the bellows 3a and 3b, and in this state, 
electrostatic capacity is measured. Upon completion of this measurement, 
the bellows 3a and 3b are caused to contract, and the measuring element 1a 
is housed in the base 2. The leading end arm unit 11a is housed in the arm 
housing section 12 through the reverse sequence of steps to the above. 
After confirming the state of the housed probe 1 with a camera 75a or the 
like, the moving apparatus 40 is caused to travel in the circumferential 
direction of the rotor unit 130 toward the measuring position P specified 
for the next stator winding 103. Subsequently, these steps are repeated 
until completion of measurement of all the stator windings 103. 
According to this embodiment, therefore, it is possible to relatively 
easily and accurately inspect the stator winding in the arrangement as it 
is without withdrawing the rotor unit from the stator unit as has been 
necessary in the conventional method, and complete the inspection 
operations within a short period of time. 
Now, unique advantages, including respective secondary effects, of the 
probe, the arm unit and the moving apparatus, will be described, in 
addition to the above-mentioned ones. 
First, as to the probe, since the measuring element is housed in the base, 
it is possible to prevent trouble in which the measuring element is caught 
by a projection in the electric rotating machine, and there is available 
another advantage of easily guiding the measuring element into the gap 
subjected to a size restriction within the electric rotating machine. 
Because the measuring element is formed into a circular shape, it is 
possible to further reduce measuring errors caused by the difference in 
the pressing direction against the stator winding and downsize the 
apparatus. 
The measuring element is pressed against the stator winding by the 
utilization of the bellows. It is therefore possible to approximately 
adjust the pressing force through pressure manipulation of the pneumatic 
source. Because the air path communicates with the right and left bellows, 
it is possible to press the right and left bellows against the stator 
winding under equal force irrespective of the center position of the 
probe. As a result, even when the inserting position of the arm shows a 
slight shear, the pressing force can be kept constant. 
The reaction force to pressing is received, not by the arm link section 
which is a support thereof, but by the stator winding (coil) on the 
opposite side. Almost any undesirable force or moment in the transverse 
direction produced in the arm link section can therefore be prevented. 
Since the outer plate of the bellows follows the external shape, it is 
possible to uniformly press the measuring element even for the curved 
portion of the stator winding. 
Then, as to the arm unit, the arm operation comprising passing through the 
gap (a narrow space) between the rotor unit and the stator- unit in the 
electric rotating machine, and after a horizontal travel, reaching a 
specified position while maintaining a linear posture by rising up 
substantially vertically can be accomplished by a simple arm driving of a 
degree of freedom 1. By changing the pressing position of the arm, the 
rise-up position of the arm leading end can be appropriately adjusted. 
As the spare arm unit is mounted, it is possible to drive the arm link 
section as it is even the arm motor becomes unserviceable. Particularly, 
even when all the drive sources inducing the spare motor stop by failure 
upon inserting the leading end arm unit of the arm link section into the 
slot, it is possible to house the arm link section in the arm housing 
section by manual operation without removing the rotor unit from the 
stator unit, thus permitting further improvement of reliability of the 
apparatus. 
Because the vertical guide door is mounted, it is possible to complete the 
extension of the curved portion of the groove for guide rail, as well as 
to set a further lower height of the arm housing section, thus permitting 
further acceleration of downsizing of the arm unit. 
As the link is formed into a frame shape, cables and the like for 
connecting the devices such as the measuring element and the apparatus 
body can be housed only within links in the arm link section without the 
need to conduct complicated transfer. 
The cylinder face circumferential moving apparatus provides advantages that 
it is possible to easily install a locus for determining the 
circumferential direction of the rotor unit within a narrow operating 
space and easily install the moving apparatus only by stretching the wire 
while appropriately maintaining tension of the pressing wire. As a result, 
travel in an arbitrary posture is possible around the rotor unit. In 
addition, even for a rotor unit having a different diameter resulting from 
a difference in model of the electric rotating machine, the simple 
apparatus configuration is applicable as it is without depending upon 
addition of a new mechanism or a change in the radius of curvature of the 
moving member. 
As engagement between the tire pulley and the toothed belt is utilized, it 
is possible to avoid almost any such trouble as slipping, shifting or 
tilting of the inspection apparatus on the rotor unit, thus permitting 
maintenance of circumferential positioning accuracy of the rotor unit. The 
wide width of the toothed belt can mainte with a high accuracy of axial 
posture of the rotor unit. 
Even with a change in the pressing wire length, fluctuation of tension can 
be reduced. An excessive or insufficient tension can be avoided. The 
inspection apparatus can stably travel in the circumferential direction on 
the cylindrical surface of the rotor unit. 
Now, examples of appllication Nos. 1 to 5 of this embodiment will 
sequentially be described below. 
1) A first example of application has a construction In which a fitting 
installable on the rotor unit 130 is provided in place of the moving 
apparatus 40, and the fitting is formed, for example, with a hoisting belt 
arranged in the middle of the ratchet. 
In this example of application, the arm unit 10 is mounted on the upper 
portion of the protecting ring 122 of the rotor unit 130, and after 
winding the hoisting belt around the rotor unit 130, the belt is hoisted 
by means of the ratchet and the arm unit 10 is secured to the protecting 
ring 122. The rotor unit 130 is rotated by controlling the rotation angle 
of the rotor rotating motor provided in the electric rotating machine, 
thereby positioning the arm unit 10 at a prescribed slot position. 
According to this example of application, therefore, it is possible to 
measure electrostatic capacity of the stator winding by guiding the probe 
to the specified measuring position without pulling out the rotor unit 
from the electric rotating machine as in the case mentioned above. 
Particularly, omission of the moving apparatus in this example permits 
achievement of a further simpler apparatus as a whole. 
2) A second example of application is based on a construction in which the 
camera 75a and the distance sensor 76 of the travel position control 
system 70 are used at strategic portions, and the origin position of the 
Inspection apparatus of the above embodiment is set in controllers of the 
foregoing motors 62 and 73. 
For example, the position of the origin in the circumferential direction 
(see direction C in FIG. 1) of the rotor unit 130 is stored as such in the 
controller of the circumferential motor 62 by manually causing the 
inspection apparatus to the position to become the origin while the 
measuring operator confirms the same through the camera 75a after 
installing the inspection apparatus on the rotor unit 130. 
The position of the origin in the axial direction (see direction A in FIG. 
1) of the rotor unit 130 is stored as such in the controller of the arm 
housing motor 73 by manually adjusting the axial position of the arm unit 
10 by means of the axial position regulater 71 while measuring the 
relative distance between the rotor unit 130 and the stator unit 120 by 
means of the distance sensor. 
According to this example of application, therefore, it is possible to set 
an origin at an arbitrary position in the circumferential and axial 
directions of the rotor unit. This provides an advantage of permitting 
ensuring a relative positional accuracy relative to the stator unit, even 
when there occurs a positional shift of the toothed belt, or a shear of 
the axial position of the rotor unit relative to the stator unit. 
3) The third example of application is based on a construction in which 
controllers are provided for the above-mentioned individual motors (servo 
motors) 29, 32, 62 and 71 and these controllers are previously set to 
control the state of excitation of the motor windings on the basis of 
measuring times of the stator winding. More specifically, in this example, 
after positioning of the probe 1 by operation of the motor, the motor 
winding becomes in a non-excited state under the effect of a control 
signal from the controller, and in this state, the stator winding 103 is 
measured. After measurement, a control signal from the controller brings 
the motor winding into an excited state, and then operates the motor. 
According to this example of application, there is particularly provided an 
advantage of further reducing the effect of noise signal in the 
measurement of electrostatic capacity caused by the driving source of the 
inspection apparatus. 
4) The fourth example of application is based on a construction in which 
there is provided a relay circuit ON/OFF-switching over the connection of 
the motor controller and the motor, in addition to the construction of the 
above-mentioned third example of application. More specifically, in this 
example of application, after controlling the motor winding to a 
non-excited state in the same steps as above, the connection between the 
controller and the motor is temporarily switched off by the operation of 
the relay circuit, leading to a non-detection state of the rotation angle 
of the motor in the controller (detecting circuit), and the stator winding 
is measured in this state. After measurement, the relay circuit brings the 
connection between the controller and the motor back to the ON state, and 
the motor winding is controlled by the same steps as above into an excited 
state, this subsequently causing the motor to operate. 
According to this example application, therefore, it is possible to inhibit 
occurrence of electric noise from the motor section, and further, to 
inhibit occurrence of electric noise of signals from the detecting circuit 
of the rotation angle of the motor. There is therefore provided an 
advantage of further reducing the effect of the occurrence of noise 
sources on the measured value of electrostatic capacity and further 
improving the measuring accuracy. 
5) The fifth example of application comprises an instructed operation 
pendant (portable unit) and a circumferential travel limiter, in addition 
to the arm unit 10 and the moving apparatus 40. 
In this example of application, the circumferential travel limiter limits 
(controls) use/non-use of the circumferential motor 62 on the basis of the 
housed state of the probe 1 in the arm unit 10, when the operator manually 
moves the inspection apparatus, by switching over the mode to the manual 
mode previously set in the instructed operation pendant. More 
specifically, when the probe 1 is not housed, the instructed operation 
pendant prohibits driving of the circumferential motor 62, and permits 
driving of the motor 62 only during housing of the probe 1. 
According to this example of application, therefore, there is particularly 
provided an advantage of avoiding the inconvenience that the inspection 
apparatus may travel in the circumferential direction of the rotor unit 
with the arm link section thereof as inserted in the slot as a result of a 
malfunction, and collide with the electric rotating machine. 
While the link wire is adopted as the arm posture keeping mechanism in this 
embodiment, the present invention is not limited to this. For example, a 
leaf spring may be provided in place of the link wire. In this case, the 
restoring force (resistance) produced in a direction reverse to the 
flexing direction of the leaf spring can maintain the link posture at an 
angle on the flexure limiting side. As a result, as in the above case, it 
is possible to achieve an arm operation in which the arm link section 
rises up while maintaining a linear posture after projection of the 
leading end link assembly. 
While the toothed belt and the toothed pulley are adopted for the moving 
apparatus in this embodiment, the present invention is not limited to 
this. For example, a roller chain may be used in place of the toothed 
belt, and sprockets may be used in place of the toothed pulley. In this 
case as well, the same effects as above are available. 
While the present invention is applied to the inspection apparatus of the 
stator winding of the electric rotating machine in this embodiment, the 
present invention is not limited to this. For example, the above-mentioned 
probe, arm unit and moving apparatus as standalone apparatuses are well 
applicable, not only to power generator-related areas such as electric 
rotating machines, but also widely in such various areas as inspection, 
test and research. 
For example, the probe is applicable, not only for the measurement of 
electrostatic capacity, but also, so far as with a measuring element is 
attachable to the side of the bellows, to an inspection apparatus using 
the measuring element, such as an ultrasonic measuring instrument using an 
ultrasonic probe. 
The arm operation in which the arm unit is, for example, horizontally 
inserted into a narrow gap, and then, for example, suddenly rises up 
vertically can be easily achieved in a simple configuration. It is 
therefore applicable particularly to an inspection apparatus using a 
measuring element, which carries out inspection to measure an arm 
structure of a high degree of freedom, a structure not allowing 
installation of a complicated driving mechanism, or a limited space such 
as a narrow gap between structures. 
The moving apparatus is applicable, in addition to the rotor unit, to an 
inspection apparatus using a measuring element, which performs inspection 
while moving the apparatus in the circumferential direction on the guide 
surface of a cylindrical structure such as a pipe, on structures 
surrounding such a cylindrical structure. 
SECOND EMBODIMENT 
Now, a second embodiment of the present invention will be described below 
with reference to FIGS. 11 to 13. In this embodiment, the arm unit of the 
foregoing embodiment is partially modified. For substantially the same or 
corresponding components as those in the first embodiment, the same or 
equivalent reference numerals are used, and the description is simplified 
or omitted here. 
The arm unit 10a shown in FIG. 11 has a modified shape of the short link 
15b inside the leading end link assembly 11a and a changed construction of 
the arm posture keeping mechanism 14. All the other components are 
substantially the same as in the above embodiment. 
The short links 15bn (assigned reference numerals "n=1, 2, . . . , x-1" 
sequentially from the leading end side) are formed, as viewed from the 
axial side surface of the pin 17n shown in FIG. 12, from frame members 
made by forming two side plates P1 and P1 into substantially a rectangular 
shape and curving the two short sides to follow the radius of curvature of 
the toothed pulley described later. 
The arm posture keeping mechanism 14a comprises a plurality of toothed 
pulleys 80n rotatably attached in a plurality of outside and inside short 
links 15an and 15bn except for the rear end inner short link 15bx in the 
leading end link assembly 11a, in place of the above-mentioned link pulley 
20, link wire 21 and spring 22, a toothed pulley 80a for constraining the 
angle (hereinafter referred to as the "angle constraining pulley") 
attached in the rearmost short link 15bx, and a plurality of toothed belts 
81n connected sequentially by alternate belt catching between adjacent 
toothed pulleys 80(n+1) and 80n including this angle constraining pulley 
80a. Among these pulleys, the outer periphery of the topmost toothed 
pulley 80.sub.1 has a projection 82. 
The arm posture keeping mechanism 14a is provided further with stoppers 
83na and 83nb at two positions before and after in the outer short link 
15an, and a stopper 84 capable of coming into contact with the projection 
82 of the toothed pulley 80.sub.1 in the topmost short link 15b1. 
Now, the operating principle of this arm unit 10a will be described below 
with reference to FIG. 12. 
As a result of connection of the toothed pulleys 80n having equal diameters 
by means of toothed belts 81n, rotation of all the toothed pulleys 80n is 
always kept in same direction, and the relative angle of adjacent toothed 
pulleys 80(n+1) and 80n is kept constant. Since the angle constraining 
pulley 80a is fixed to the rearmost short link 15bx, all the toothed 
pulleys 80n have a uniform angle relative to the rearmost short link 15bx. 
Further, since the rearmost short link 15bx travels only on the horizontal 
portion of the guide rail 25, the rotation angle of the angle constraining 
pulley 80a becomes constant relative to the arm unit 10a. 
Even when the arm link section 11 flexes, therefore, the angle of all the 
toothed pulleys 80a is constant relative to the guide rail 25 (for 
example, the triangle marks in FIG. 12 always maintains a direction). 
Now, the rise-up operation of the arm link section 11 will be described 
below with reference to FIG. 13. 
First, as shown in FIG. 13A, the arm link section 11 travels along the 
guide rail 25, and when the topmost short link 15b1 flexes, this short 
link 15b1 rotates relative to the first toothed pulley 80.sub.1. Then, 
when the projection 82 of the toothed pulley 80.sub.1 comes into contact 
with the stopper 84, the toothed belt 81.sub.1 causes the short link 15b1 
to rotate around the axial direction of the pin 17.sub.1 in direction K in 
FIG. 13A. 
Then, as shown in FIG. 13B, when the arm link section 11 is pushed out, the 
topmost short link 15b1 comes into contact with the stopper 83.sub.1 a in 
the adjacent short link 15a1, thus maintaining the linear posture of the 
both short links 15b1 and 15a1. Thus, the toothed belt 81.sub.2 causes the 
adjacent short links 15b1 and 15a1 to integrally rotate around the pin 
17.sub.2 in direction L. 
In the meantime, as shown in FIG. 13C, the topmost short link 15b1 
continues to receive the K-direction moment in FIG. 13C under the effect 
of the toothed belt 81.sub.1, thus maintaining the contact state between 
this short link 15b1 and the stopper 83.sub.1 a and keeping the linear 
posture of the adjacent short links 15b1 and 15a1. Further, when the arm 
link section 11 is pushed out, the short link 15a1 comes into contact with 
the stopper 831b and forms a straight line shape with the short link 15b2. 
As a result of sequential repetition of the above steps, the portions of 
the individual links 15an and 15bn projecting from the guide rail 25 
independently rise up while maintaining the linear shape. 
By adjusting the angle of the angle constraining pulley 80a, it is possible 
to adjust the allowable angle until contact of the projection 82 of the 
toothed pulley 80.sub.1 at the arm leading end with the stopper 84, and to 
adjust the inclination of the straight line formed by the arm link section 
11. 
According to this embodiment, therefore, particularly the link portion 
projecting from the guide rail can rise up while maintaining the linear 
posture, and this provides an advantage of adjusting the rise-up angle of 
the arm link section. 
THIRD EMBODIMENT 
Now, a third embodiment of the present invention will be described below 
with reference to FIG. 14. This embodiment is achieved by modifying the 
probe in the above embodiment. For substantially the same or corresponding 
components as in the above embodiment, the same or equivalent reference 
numerals are used, and the description is simplified or omitted here. 
In the inspection apparatus shown in FIG. 14, the same probe 1 as above is 
attached to a portable rod member 90. This rod member 90 comprises a rod 
91 supporting the probe 1, a grip 92 arranged on the rear end side of the 
rod 91, a plate-shaped positional guide 93 fitted adjustably at an 
appropriate position in the axial direction of the rod 91, and a tube 94 
connected to the rear end side of the rod 91. An air path of the probe 1 
communicates to a separate pneumatic circuit (not shown) through an air 
path not shown in the rod and the tube 94. Remote-operating buttons 95 and 
95 are provided at appropriate positions of the grip 92, are electrically 
connected to the pneumatic circuit. 
Now, operations of this embodiment as a whole will be described below. 
Assume that the rotor unit 130 is removed in the same manner as in the 
conventional method upon inspection of the stator winding 103 of the 
electric rotating machine. Upon removal, the axial position of the 
positional guide is previously adjusted on the basis of the measured 
position of the stator winding 103 (see direction H in the drawing). Then, 
the measuring operator inserts the probe 1 while holding the grip 92 by a 
hand. 
Then, when the positional guide 93 hits the stator winding, the pneumatic 
circuit (supply circuit) by acting on the operating button 95 at this 
position to send air to the air path in the probe 1 through the tube 94 
and the rod 91 and thus to cause the bellows 3a and 3b on the both sides 
of the base 2 to expand (see direction J in the drawing). Then, 
measurement of electrostatic capacity is started by pressing the measuring 
element 1a against the surface (measuring position) of the stator winding. 
Upon completion of measurement, the pneumatic circuit (intake circuit) is 
operated by means of the operating button 95 to cause the bellows 3a and 
3b to contract through the air path reversed to the above. 
According to this embodiment, therefore, upon inspection, in the same 
manner as in the conventional method, carried out by removing the rotor 
unit from the stator unit, it is possible to accurately and relatively 
easily position the measuring element at a position of the stator winding 
at a certain depth, and to press the measuring element against the surface 
of the stator winding with a certain force, thus permitting remarkable 
improvement of operability of pressing. 
FOURTH EMBODIMENT 
The electrostatic capacity measuring apparatus of the stator winding of the 
present invention is formed by connecting a data analyzer to the measuring 
instrument not shown of the measuring element to at least any one of the 
apparatus configurations of the first and the second embodiments This data 
analyzer comprises, for example, a personal computer, and upon receipt of 
measured data of electrostatic capacity from the measuring instrument of 
the measuring element, carries out analysis and evaluation of such 
measured data by executing a previously set algorithm for evaluating 
electrostatic capacity. 
In the measuring method using such an apparatus, the probe is guided toward 
the gap of the target stator winding by driving the foregoing arm unit, 
thereby positioning the same. The status is therefore adjusted by 
causing-the bellows of the probe to contract into a state in which the 
measuring element and the stator winding are mutually in non-contact. 
Electrostatic capacity in air between the both components is measured in 
this non-contact state by means of the measuring element as an initial 
value regarding the initial condition of the stator winding, and the 
measured value is sent to the data analyzer through the measuring 
instrument. 
Then, the measuring element is brought into contact with the stator winding 
by causing the bellows of the probe to expand. In this state, 
electrostatic capacity is measured, and the measured value is sent to the 
data analyzer through the measuring instrument of the measuring element in 
the same manner as above. 
According to this embodiment, therefore, in the measurement of 
electrostatic capacity of the stator winding, electrostatic capacity in 
the non-contact state of the measuring element and the stator winding is 
measured as an initial value. There is therefore an available advantage of 
grasping and evaluating the initial condition before measurement of each 
of the plurality of stator windings, and further improving accuracy and 
reliability of measured data. 
In this embodiment, the present invention is applied to an automatic 
measuring instrument using an arm unit. The present invention is not 
however limited to this. For example, it is applicable also to a manual 
measuring instrument using a rod member as in the third embodiment. 
FIFTH EMBODIMENT 
In the electrostatic capacity measuring instrument of the stator winding 
shown in FIG. 15, a discharge circuit 78 and a controller 79 for 
controlling operations thereof are connected to the measuring element 1a, 
in addition to at least any one of the apparatus configurations of the 
above embodiments (description omitted). The discharge circuit 78 
temporarily performs short-circuiting of the connecting cable between the 
measuring element 1a and an electrostatic capacity input terminal of the 
measuring instrument not shown upon receipt of an instruction regarding 
discharge request from, for example, the controller 79, to a grounding 
terminal. 
In this measuring instrument, the discharge circuit 78 is operated by 
issuing a discharge request instruction of the measuring element 1a from 
the controller 79 to the discharge circuit 78 before execution of 
measurement of electrostatic capacity, and charge of the measuring element 
1a in the preceding run of measurement is discharged through the 
connecting cable. 
According to this embodiment, therefore, upon measuring electrostatic 
capacity of the stator winding, charge of the measuring element is 
discharged before measurement. Each of a plurality of stator windings can 
be measured almost under the same conditions at least regarding charge, 
thus further improving accuracy of measured data. 
SIXTH EMBODIMENT 
In a electric rotating machine, of which the operating voltage is as high 
as about 20 kV, a treatment for reducing electric field intensity of the 
stator winding (prevention of corona) near the iron core end is usually 
applied. Particularly, a portion of several tens of mm from the iron core 
end is subjected to a treatment inhibiting low-resistance corona. 
Therefore, by measurement of electrostatic capacity of such a portion 
subjected to a low-resistance corona preventing treatment, an accurate 
value necessary to inspecting a stator winding can hardly be expected. 
In this embodiment, therefore, when measuring electrostatic capacity of a 
stator winding, the measuring position should not be the corona preventing 
portion, but should preferably be the portion exposed to outside the 
machine from the iron core end, or more preferably, a position near the 
transition portion from straight to curved portions of the stator winding. 
By selecting a measuring position excluding the corona preventing portion, 
a plurality of stator windings can be measured under almost the same 
conditions at least regarding the effect of low-resistance corona 
preventing treatment, thus providing an advantage of further improving 
accuracy of measured data. 
SEVENTH EMBODIMENT 
In general, a electric rotating machine suffers from production of much 
stray electrostatic capacity, and is installed in an environment 
containing produced stray electrostatic capacity. When measuring 
electrostatic capacity of a stator winding, therefore, disregarding the 
effect of stray electrostatic capacity is not wise at all. 
In this embodiment, therefore, there are adopted, as measuring conditions 
of electrostatic capacity of a stator winding, a measuring element capable 
of excluding produced stray electrostatic capacity, and an AC-type 
measuring instrument permitting correction of the effect of stray 
electrostatic capacity superposed on the measuring lead. For the measuring 
frequency, since the electrostatic capacity value to be measured is small 
and a frequency near the commercial one or a high frequency leads to easy 
oscillation, it is set in the proximity of 1 kHz with a small external 
stray electrostatic capacity. 
Since the measuring conditions are selected so as to avoid the effect of 
external stray electrostatic capacity, it is possible, when measuring 
electrostatic capacity of a stator winding, to reduce a measuring error 
caused by stray electrostatic capacity and to obtain more accurate 
measured results. 
EIGHTH EMBODIMENT 
The electrostatic capacity measuring apparatus of this embodiment is 
provided with a surface condition inspecting system (not shown) for 
inspecting the surface condition of the contact portion between the 
measuring element and the stator winding, in addition to the same 
apparatus configuration as at least any one of the above-mentioned 
embodiments. When measuring electrostatic capacity by bringing the 
measuring element into contact with the stator winding through expansion 
of the bellows of the probe, this system simultaneously calculates a 
resistance value by means of a measuring instrument not shown and 
determines the contact state between the measuring element and the stator 
winding by the use of the measured resistance value, thereby inspecting 
the surface condition of the contact portion. 
In this system, when a calculated resistance value is within a previously 
set range, the measuring element is in accurate contact with the stator 
winding. If the measured resistance value is near infinity, the measuring 
element is not in accurate contact with the stator winding, that is, it is 
determined that the surface of the stator winding contains irregularities, 
or the probability of such irregularities is high. 
According to this embodiment, therefore, when measuring electrostatic 
capacity of a stator winding, it is possible to know the surface condition 
of the contact portion which cannot be visually observed before 
measurement, thus providing an advantage of previously avoiding 
measurement at a portion containing a defective surface condition, thus 
further improving reliability of a measured value. 
As an example of application of this embodiment, a system which 
automatically detects a desired measuring position is making it possible 
to bring the measuring element accurately into contact with the stator 
winding. This system, in addition to a measuring instrument measuring the 
above-mentioned resistance value, positions the probe at a desired 
measuring position by driving the arm unit and the moving apparatus in 
response to the result of determination based on that resistance value. 
Operation of this system is as follows. First, when it is determined that 
the measuring element is not accurately in contact with the stator 
winding, the bellows of the probe are caused to contract to arrange the 
measuring element in non-contact with the stator winding. 
Electrostatic capacity and resistance value are therefore measured by 
moving the arm unit for each distance of several millimeters to the stator 
iron core side or to opposite side in the axial direction of the rotor 
unit, and then bringing the measuring element into contact with the stator 
winding through expansion of the bellows of the probe. These operations 
are repeated until the same travels for several cm. In the meantime, the 
operation is discontinued at the point when the measured electrostatic 
capacity and resistance value show values within previously set ranges, 
and the axial position at this moment are stored in a memory not shown in 
the system. This operation covers the case of the axial direction, and the 
steps are the same even for the radial direction of the rotor unit. 
NINTH EMBODIMENT 
The electrostatic capacity measuring apparatus shown in FIG. 16 is formed 
by constructing a measuring element 1a from copper foil, applying the 
copper foil onto a surface of the cushion 4, affixing a guard 80 formed by 
copper foil so as to cover the other surface, providing an insulating 
plate 81 made of an insulating material such as an epoxy resin on the back 
side of this guard 80, and attaching the measuring element 1a through the 
insulating plate 81 to the same probe 1 as that mentioned above. The other 
components are substantially the same as above. 
According to this measuring apparatus, in which the measuring element is 
provided with the insulating plate and the guard, it is possible to shield 
stray electrostatic capacity. Because of the cushion provided between the 
measuring element and the guard, the measuring element follows the surface 
condition of the stator winding, and it is thus possible to uniformly 
press the measuring element against the curved portion. 
TENTH EMBODIMENT 
The inspection apparatus shown in FIG. 17 is provided with a positioning 
system which performs positioning of the probe 1 by detecting the coil 
width in the radial direction of the stator winding 103, in addition to 
the probe 1, the arm unit 10 and the moving apparatus 40 as described 
above (description omitted). 
This positioning system comprises coil width detecting sensors 82a and 82b 
such as optical sensors mounted at two upper and lower positions in the 
probe 1, and a controller (not shown) which controls driving of the arm 
unit 10 on the basis of information regarding the coil width from these 
sensors 82a and 82b. 
Operations of the system are as follows. First, when positioning the probe 
1 to the measuring position of the stator winding 103a, the arm link 
section 11 of the arm unit 10 is caused to travel forward and upward under 
the control of the controller, and the upper edge of the stator winding 
103a on the outside diameter side is detected by means of a sensor 82a 
provided on the upper part side of the probe 1. Subsequently, the arm link 
section 11 is caused to travel backward and downward, and the lower edge 
of the stator winding 103a is detected by means of a sensor 82b provided 
on the lower part side of the probe 1. The winding width in the radial 
direction of the stator winding 103b on the outside diameter side in the 
controller on the basis of a detection signal thereof, and the probe 1 is 
positioned by driving the arm unit 10 so that the center of width is at 
the measuring position. This operation is similarly carried out also for 
the stator winding 103b on the inside diameter side. 
According to this embodiment, therefore, there is provided an advantage of 
accurately positioning the probe by determining the center for each of a 
plurality of stator windings, in addition to the same effects as above. 
ELEVENTH EMBODIMENT 
The inspection apparatus of this embodiment is provided with a positioning 
system which positions the probe in the gap of the stator windings on the 
basis of an image from a camera (see reference numeral 75a in FIG. 1) in 
addition to the probe, the arm unit and the moving apparatus as in the 
above case (description omitted). This system has an image processor which 
executes a previously set image processing algorithm by incorporating an 
image regarding the gap of the stator winding taken by the camera, and a 
controller which controls the circumferential driving of the moving 
apparatus on the basis of the result of processing by this image 
processor. 
This system incorporates an image from the camera during travel of the 
moving apparatus in the circumferential direction, determines whether or 
not the incorporated image matches with a center image of the gap of the 
stator winding previously pattern-recognized, and if determined to be 
matching, discontinues the circumferential travel of the moving apparatus 
at this point. 
According to this embodiment, therefore, it is possible to insert the probe 
along the center position of the gap of the stator winding and thus to 
avoid almost any inconvenience of collision of the probe with the stator 
winding. 
As an example of application of this embodiment, a positioning system may 
be adapted, based on steps of pattern-recognizing an image with the image 
recorded in the preceding run of measurement, and discontinuing the 
circumferential travel of the moving apparatus at the point when these 
images are in agreement. In this case, even when measuring the same stator 
winding a plurality of times, it is possible to set the insertion slot of 
the probe at the same position every time, thus providing an advantage of 
further improving reliability of measured data. 
TWELFTH EMBODIMENT 
The inspection apparatus of this embodiment is provided with an arm unit, a 
moving apparatus, an instructed operation pendant (not shown), and 
circumferential travel limiter (not shown) as in the above-mentioned first 
embodiment (fifth example of application). 
In this embodiment, when the operator manually moves the inspection 
apparatus, the mode should be switched over to the manual mode by means of 
the instructed operation pendant. At this point, the circumferential 
travel limiter limits the use of the circumferential motor in response to 
the state of arm housing. More specifically, if it is not housed in the 
arm unit, driving of the circumferential motor is prohibited by the 
instructed operation pendant, and the use of this motor is allowed only in 
a state in which the probe is housed in the arm unit. According to this 
embodiment, therefore, it is possible to avoid inconvenience in which 
circumferential travel is executed erroneously by the operator with a 
probe or the arm link section as inserted in the gap of the stator winding 
and it collides with the stator winding. 
THIRTEENTH EMBODIMENT 
The inspection apparatus shown in FIG. 18 has a construction in which the 
same insulator 81 and a guard 80 as those in the foregoing ninth 
embodiment, and measuring elements 1a and 1b via a cushion material 4 are 
attached on the outer surfaces of the bellows 3a and 3b on the both sides 
of the probe 1, and signal lines from the both are connected through a 
measuring element switching circuit 83 to a controller 79. The switching 
circuit 83 comprises relays and the like, and can switch over between the 
right and left measuring elements 1a and 1b in response to an instruction 
from the controller 79. 
Operations of this apparatus are as follows. The probe 1 is moved to the 
measuring position, and electrostatic capacity of a measuring element 1a 
is measured through the switching circuit 83. Subsequently, electrostatic 
capacity of the other measuring element 1b is measured by means of the 
switching circuit 83. According to this embodiment, therefore, 
electrostatic capacity of two static windings can be measured at a 
measuring position, thus providing an advantage of further improving 
measuring efficiency. 
FOURTEENTH EMBODIMENT 
The inspection apparatus shown in FIG. 19 is the application of the present 
invention to a manual type measuring apparatus in which the foregoing 
moving apparatus is omitted, and more specifically, is provided with a 
probe 1 and an arm unit 10b for arm-driving the same. 
A transferable arm housing section (formed with substantially the same 
enclosure 24b as that in the above embodiment, a guide rail 25b and a 
vertical guide door 34b) 210 are provided in the arm unit 10b. The section 
210 is used for housing substantially the same link assembly 11a as the 
above-mentioned leading end link assembly together with a probe 1 and 
guiding the arm driving of the same, an axial adjuster 211 using a nut 
capable of adjusting the position of the probe 1 in the axial direction 
relative to the stator winding 103, arranged on the leading end side of 
the arm housing section 210 and a radial adjuster 212 connected to the 
rear end of the link assembly 11a and capable of adjusting the radial 
direction of the probe 1 relative to the stator winding 103. 
Operations of this apparatus are as follows. First, the nut 213 of the 
axial adjuster 211 is adjusted, and the position of a radial stopper not 
shown in the arm housing section 210 is previously aligned with the radial 
measuring positions of the stator windings in two stages 103a and 103b. 
Then, the arm housing section 210 is placed on the rotor unit 130 covered 
with a protecting sheet (not shown), and the axial adjuster 211 on the 
leading end side is pressed against a buffgaffle 214 on the stator iron 
core side to fix the axial position of the arm housing section 210 (see 
arrow al in the drawing). 
Then, in a state in which the arm housing section 210 is manually held, the 
radial adjuster 212 is manually pressed (see arrow a2 in the drawing) to 
the position of the radial stopper, thereby causing the link assembly 11a 
to travel along the guide rail 25b. The probe 1 on the leading end side 
thereof is guided to the radial measuring positions of the two stage 
stator windings 103a and 103b, respectively (see arrow a3 in the drawing). 
Then, the bellows are caused to expand by applying a pneumatic pressure in 
the probe 1, and the measuring element 1a is brought into contact with the 
stator winding 103 for measurement of electrostatic capacity. 
Upon completion of this measurement, the bellows are caused to contract by 
absorbing air in the probe 1, and the probe is housed in the arm housing 
section 210 by pulling the radial adjuster back to the original position. 
The arm housing section 210 is transferred to outside the generator, and 
the arm housing section 210 is caused to travel to the circumferential 
position of the rotor unit 130 looking out the stator windings 103a and 
103b on the sides to be subjected to the next run of measurement. Then, 
the same steps as above are followed, and subsequently, all the stator 
windings 103 are measured by sequentially repeating these steps for the 
entire circumference. 
According to this embodiment, therefore, even when the stator winding is 
inspected without pulling out the rotor unit from the stator unit, it is 
possible to accurately and easily position the measuring element to a gap 
between the stator windings and at a certain depth of the stator winding 
and to the same position at a certain distance from the iron core section, 
thus permitting remarkable improvement of operability of measurement. 
FIFTEENTH EMBODIMENT 
The inspection apparatus shown in FIG. 20 is provided with a probe 1 and an 
arm unit 10c, as well as with a holding mechanism 310 which 
circumferentially movably holds the arm unit 10c through a recess space 
between a protecting ring 122 holding a rotation shaft 123 and a cooling 
fan attachment plate (flange) 220. 
An arm housing section 210 mounting a link assembly 12a similar to that in 
the fourteenth embodiment and an air cylinder mechanism 250 (arm driving 
mechanism) for arm-driving the link assembly 11a are provided in the arm 
unit 10c. The arm housing section 210 is provided with a radial adjuster 
212a at the rear end of the link assembly 209, and two-stage variable 
stoppers 248a and 248b in response to the radial measuring position of the 
two-stage stator windings 103a and 103b as stoppers thereof. 
The air cylinder mechanism 250 has an enclosure 251 attached to the 
trailing end of the arm housing section 210. An air cylinder 252 is 
arranged in this enclosure 251, and a piston 253 thereof is connected to 
the radial adjuster 212a. This air cylinder mechanism 250 feeds air into 
the air cylinder 252 by operating an air cylinder switch 255 of an 
operating section 254 formed on the rear end side of the enclosure 251 and 
starts arm-driving of the link assembly 11a by causing the radial adjuster 
212a of travel forward by the stroke of the piston. At a point when the 
radial adjuster 212 comes into contact with the two-stage variable 
stoppers 248a and 248b, respectively, arm-driving of the link assembly 11a 
is discontinued. 
The holding mechanism 310 comprises a front/rear adjusting unit 311 
attached to the enclosure 251 of the air cylinder mechanism 250 and 
performing fine adjustment as a whole, and a pair of transverse rollers 
holding the opposite surfaces of the protecting ring 122 and the flange 
220 as a pair of roller running surfaces, movably in the circumferential 
direction, i.e. a stationary transverse roller 312 on the protecting ring 
122 side and movable transverse roller 313 on the shaft 220 side. The arm 
unit 10 is held by moving the movable transverse roller 313 relative to 
the stationary transverse roller 312 between the protecting ring 122 and 
the flange 220 so that the movable transverse roller 313 stretches in the 
axial direction, thereby determining the initial axial position of the arm 
unit 10 by means of the both transverse rollers 312 and 313 and the 
front/rear adjusting unit 311. 
This holding mechanism 310 has a belt 314 for preventing the arm unit from 
dropping, capable of being wound in the circumferential direction by 
projecting in the axial direction on the rotation shaft 123 side on the 
end surface of the protecting ring 122, and a circumferential roller 315 
rotatably attached to the front/rear adjusting unit 311 with the rotation 
shaft 123 sides as the roller traveling surface. These components 314 and 
315 prevent dropping of the arm unit 10 and facilitate travel thereof in 
the circumferential direction. 
Now, operations in this embodiment as a whole will be described below. 
First, the positions of the two-stage variable stoppers 248a and 248b are 
previously aligned with the measuring positions of the two-stage stator 
windings 103a and 103b, respectively. Then, the arm housing section 210 is 
placed on the rotor unit (protecting ring 122) 130 having a curing sheet 
(not shown) wrapped. The air cylinder 252 is piston-driven by pushing the 
air cylinder switch 255, and stopped by pressing the same against the 
variable stopper 248a on the rear end side, thereby guiding the probe 1 to 
a radial measuring position of the stator winding 103b on the inside 
diameter side. A probe opening/closing switch 256 provided in the 
operating section 254 is pressed to cause expansion by applying a 
pneumatic pressure in the probe 1, thus carrying out measurement of 
electrostatic capacity in the same manner as above. 
Upon completion of measurement of electrostatic capacity of the stator 
winding 103b on the inside diameter side, the probe 1 is caused to 
contract by acting on the switch 255. Then, by operating the air cylinder 
252 by pressing again the air cylinder switch 256, and pressing the same 
to the variable stopper 248b on the leading end side, the probe 1 is 
guided to the measuring position of the stator winding 103a on the outside 
diameter side. At this point, electrostatic capacity is measured by 
applying a pneumatic pressure through pressing of the switch 256 as in the 
case described above. Upon completion, probe 1 is caused to contract, and 
housed in the arm housing section 210, thus completing a run of 
measurement for a slot. Subsequently, the arm unit 10 is manually moved in 
the circumferential direction via a circumference roller 315 and the arm 
housing section 210 is manually guided to the slots over the entire 
circumference for measurement. 
According to this embodiment, therefore, even when a stator winding is 
inspected without pulling out the rotor unit from the stator unit, it is 
possible to accurately and easily position the measuring element at a 
certain depth of the stator winding in a prescribed gap of the stator 
winding to the same position at a certain distance from the iron core end, 
thus permitting remarkable improvement of operability as to measurement. 
SIXTEENTH EMBODIMENT 
Now, a sixteenth embodiment of the present invention will be described 
below with reference to FIGS. 21 and 23. 
The inspection apparatus shown in FIG. 21 is provided with a probe 1 and an 
arm unit 10d. As shown in FIG. 22, the probe 1 has two stage circular 
bellows 3a and 3b provided on the both sides, respectively, with a base 2 
in between. A non-skid material 5 is attached through a cushion 4a to the 
outsides of the two-stage bellows 3a and 3a, and a measuring element 1a is 
attached through a cushion 4b to the outsides of the other two-stage 
bellows 3b and 3b. The probe as a whole is formed into an oval shape 
allowing further expansion of the contact area without protruding from the 
stator winding. 
In this inspection apparatus, various components are added with a view to 
ensuring smooth guiding of the probe 1 to the stator winding 103 and 
positioning thereof along with the adoption of the oval probe of the 
multiple bellows type. For example, the probe 1 is provided, as shown in 
FIG. 23, with probe guards 218 for preventing contact damage on the both 
ends in the axial direction of the base 2, a horizontal guide 215 for 
securing the probe 1 at a prescribed angle at the measuring position 
between the stator windings 103, a probe wheel 216 for reducing resistance 
upon feeding the probe provided at the leading end of the probe 1, and a 
link wire 21 for giving tension by a spring not shown so as to guide the 
probe 1 in a certain direction. 
The arm unit 10d has an arm housing section 210 for housing a link assembly 
11a similar to the leading end link assembly described above, together 
with a probe a, and for ensuring smooth feed thereof, and an arm driving 
mechanism mounting an arm housing motor 29 for arm-driving the link 
assembly 11a for this arm housing section 210. An enclosure 24b of the arm 
housing section 210 is set to a size capable of being installed in a gap 
between a nose ring 219 securing the end of the stator winding 103 and a 
rotor unit 130. A guide rail 25b similar to that in the above case, a 
vertical guide door 34b and a guide wheel 217 for reducing resistance upon 
feeding the probe to the leading end of the vertical guide door 34b are 
attached to the enclosure 24b. 
Now, operations of this embodiment as a whole will be described below. 
First, the probe 1 is sent out from the vertical guide door 34b while 
moving the link assembly 11a along the guide rail 25b by the drive of the 
arm housing motor 29. This is smoothly accomplished with a guide wheel 217 
and a probe wheel 216. 
The probe 1 receives tension of a link wire 21 upon passing through the 
vertical guide door 34b and rotates around the connecting shaft with the 
link assembly 11a, and discontinues rotation at the point when a 
horizontal guide 215 comes into contact with the bottom surface of the 
link assembly 11a. The stop position of the probe 1 is at a point where 
the base axis of the probe 1 corresponds to a direction substantially at 
right angles to the arm axis of the link assembly 11a, i.e., a direction 
parallel to the axial direction of the stator winding 103a. 
The probe 1 feeds while maintaining the horizontal posture is protected by 
a probe guard 218, so that it is guided without suffering from contact 
damage with the stator winding 103 and positioned at the measuring 
position. 
Then, electrostatic capacity is measured by the probe 1. At this point, the 
two-stage bellows 3a and 3b, having a circular shape, expand almost 
uniformly, and brings the oval-shaped measuring element 1a into contact 
with the stator winding 103 to start measurement. Upon completion of 
measurement, the probe 1 is housed in the arm housing section 210. This 
probe housing is smoothly accomplished by means of a guide wheel 217 and a 
probe wheel 216 as in feeding thereof. 
According to this embodiment, therefore, the measuring element is made 
larger in size in an oval shape so as to achieve a larger contact area 
without coming off the stator winding. It is therefore possible to 
increase the measuring reference value to minimize factors causing a 
measuring error such as noise, and thus to further improve the measuring 
accuracy. In the construction of this embodiment, the probe is kept in a 
horizontal posture relative to the rise-up posture of the arm. The probe 
can therefore be guided in parallel with the upper and lower stator 
windings, respectively, and as a result, operability for measurement can 
be remarkably improved. 
Because a plurality of circular bellows are combined, there is provided 
another advantage of uniformly applying a pneumatic pressure to the 
bellows and ensuring stable expansion of the measuring element than in a 
case with a single bellows. 
SEVENTEENTH EMBODIMENT 
Now, a seventeenth embodiment of the present invention will be described 
below with reference to FIGS. 24 and 25. 
The electrostatic capacity measuring apparatus shown in FIG. 24 is provided 
with a cylinder face circumferential moving apparatus (cylinder track 
measuring apparatus) 40a attachable to a flange 220 for a cooling fan for 
cooling a stator winding 103 or a rotor unit 130. 
This moving apparatus 40a has a cylindrical track base 221 attached to the 
radial outside of a flange 220, a strip-shaped track guide 228 supported 
and secured by the base 221 through a track fixer in a state in which it 
is wound around the outside surface (upper surface) in the radial 
direction of the base 221, and a moving member 240 which causes an arm 
unit 10 along a circumferential track of the rotor unit 130 secured by the 
track guide 228. 
The track base 221 is formed so as to be capable of coping even with a 
deformed cooling fan flange having a different exterior shape through 
adjustment of a circumference adjuster 231 using a pin joint mechanism, 
and attached through a plurality of fan fitting holes 220a on an axial 
side of the flange 220 by means of a plurality of fan bolts 222. 
The moving member 240 has a body 57a substantially identical with the 
above-mentioned moving apparatus body 57. Driving wheels 224 . . . 224 are 
provided on this body 57a, and driven wheels 225 . . . 225 are connected 
through a fixed link or a sliding link 227 at opposite positions with the 
track guide 228 in between. The sliding link 227 is provided diagonally to 
the fixed link 226, and can be attached while housing the moving member 
240 from the track guide 228. A tensioner 229 for producing frictional 
force by pulling up the wheels 224 onto the track guide 228 side is 
provided between the body 57a and the driven wheels 225. 
When installing this moving member 40a on the rotor unit 130, the track 
base 221 is first attached to the entire circumference of the cooling fan 
flange 220 through adjustment of the pin joint mechanism. The track guide 
228 is wound on the upper surface of the base 221. Then, the moving member 
240 is placed on the track guide 228 at a position where the sliding link 
227 has been housed. It then suffices to act on the tensioner 229 by 
inserting the sliding link 227. 
According to this embodiment, therefore, it is possible to measure all the 
circumference by securing the track guide on the cooling fan flange, and 
hence to considerably improve operability regarding measurement. 
EIGHTEENTH EMBODIMENT 
Now, an eighteenth embodiment of the present invention will be described 
below with reference to FIGS. 26 and 27. 
The inspection apparatus shown in FIGS. 26 and 27 is a portable type manual 
narrow portion measuring apparatus used when inspecting a stator winding 
103 by removing a rotor unit 130 as in the above-mentioned third 
embodiment, and has a probe 1 of substantially circular shape to which a 
measuring element is attached through an expansible bellows, and a 
portable universal rod 90 supporting the probe 1. 
A probe guard 218 for preventing contact damage or the like occurring upon 
inserting into the stator winding 103 is provided on the edge of the probe 
1. Circumferential positioners 205 and 205 formed by nuts and bolts having 
a plurality of free faces are attached to two points on the edge of the 
probe 1. This positioner 205 keeps a constant circumferential distance by 
pressing the free face thereof against the side of the stator winding 103, 
and performs circumferential positioning by following the curved portion 
of the winding 103. 
An adjusting nut 206 for freely adjusting the length, an axial positioner 
203 and a radial positioner 204 on the probe 1 side (reference numeral 201 
in the drawing represents the cushion), an operating button 95 for 
carrying out operation regarding expansion and contraction of the probe 1 
and displays 291a and 291b thereof on the grip side are provided on the 
universal rod 90. 
Operations of this embodiment as a whole will be described below. 
First, the adjusting nut 206 and the various positioners 203 to 205 are 
previously adjusted before insertion of the probe 1 into the stator 
winding 103 in response to a desired measuring position of the stator 
winding 103. For example, the length of the rod member 90 is adjusted by 
means of the adjusting nut 206 in response to the size of the stator 
winding 103; the set size of the axial positioner is based on that of the 
iron core support 300; the set distance of the radial positioner 204 is 
based on the position of the end of the stator winding 103 in a state in 
which the rod member to be connected to the axial positioner 203 is held; 
and the set position of the circumferential positioner 205 is aligned with 
the measuring position between the stator windings 103. 
The probe 1 is contracted by acting on the operating button 95, and 
inserted into the gap of the stator windings 103. Because the probe guard 
218 permits avoidance of catch with the stator windings 103, probe 
insertion is smoothly accomplished, and completed when the positioners 203 
to 205 come into contact with the stator windings 103. 
Once the probe 1 is positioned, the probe 1 is caused to expand by acting 
on the operating button 95. After confirming that a prescribed pressure is 
reached from a change in color of the displays 291a and 291b, measurement 
of electrostatic capacity is started. Upon completion of this measurement, 
the operating button 95 is pressed again to cause contraction of the probe 
1, and subsequently, these operations are conducted for the remaining 
stator windings 103. 
According to this embodiment, therefore, even when carrying out inspection 
by pulling out the rotor unit from the stator unit, it is possible to 
accurately and easily position the measuring element at a certain depth of 
the stator windings, at the same position at certain distance from the 
stator windings and the iron core end, thereby further improving 
operational efficiency. 
While a circular probe is used in this embodiment, the present invention is 
not limited to this. For example, an oval probe (substantially circular) 
as in the above-mentioned sixteenth embodiment may be adopted. In this 
case, combination of a plurality of stages of circular bellows permits 
achievement of a further larger contact area of the measuring element with 
the stator windings, and there is available an advantage of further 
improving the measuring accuracy by reducing the effect of factors causing 
a measuring error such as noise with a higher measuring reference value. 
NINETEENTH EMBODIMENT 
The inspection apparatus shown in FIG. 28 is a portable type manual narrow 
portion measuring apparatus and has a probe 1, and a portable measuring 
rod (rod member) 90 supporting the same. The probe 1 is attached rockably 
forward/rearward and right/left through a spherical convexity (probe 
attaching portion) 90a for joint provided at the leading end of the 
measuring rod 90. 
The probe 1 is formed by constructing the measuring element 1a from copper 
foil 200a, applying the same to a surface of a cushion material 201, 
attaching an insulating plate 202 onto the other surface of the cushion 
material 201 through grounding copper foil 200b, and forming a spherical 
recess 202a engageable with the spherical convexity 90a to form a joint in 
the plate 202. 
According to this embodiment, therefore, the probe is rockably attached at 
the leading end of the measuring rod, and Oit is possible to bring the 
probe into contact more accurately with the stator winding without being 
restricted by the position (posture) of the measuring rod. The cushion 
material provide another advantages of bringing the measuring element into 
close contact so as to follow the surface of the stator winding. This 
effect can be maximum when guiding the measuring element into a place 
where stator windings and the like form a complicated shape and bringing 
the same into contact with the stator windings.