JPH0723708B2 - Air motor for starter of internal combustion engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an air motor for a starter of an internal combustion engine such as a gas turbine.

(Prior Art) In a conventional air motor of this type, an inner cylinder having an eccentric hollow hole is fitted in a cylindrical casing, and disk-shaped end plates are fixed to both ends of the inner cylinder. A cylindrical rotor is rotatably supported in the hollow hole, and a flat blade is inserted into and out of a plurality of slots radially formed on the outer peripheral surface of the rotor. The slave shaft is configured to be disconnectable from the starting shaft of the internal combustion engine via the starting rotary shaft of the transmission. In order to start an internal combustion engine with this air motor, compressed air is supplied from the inner peripheral lower part of the eccentric hollow hole to the working chamber formed between the adjacent movable blades, and the compressed air is moved downward. By branching and supplying into the slot, the movable blade protrudes from the slot, and its tip end surface abuts the wall surface of the eccentric hollow hole to keep the working chamber airtight. for that reason,
The compressed air acts on the surface of the movable blade to rotate the rotor. The starting rotation shaft of the transmission is rotated by the rotor shaft of the air motor, and at the same time, is moved axially by the compressed air supplied separately and is connected to the starting shaft of the internal combustion engine to start rotation. To do.

(Problems to be Solved by the Invention) According to the above-described conventional air motor, due to the frictional force between the surface of the movable blade and the inner surface of the slot, the movable blade does not completely project from the slot, and the tip surface of the movable blade is eccentric. A gap may be formed between the hollow wall and the wall surface.

Therefore, compressed air leaks to the outside from the working chamber before the pressure of the branched air in the slot rises, and further, the air pressure in the working chamber acts in the direction of pushing the movable blade into the slot. Further, there is a problem that the movable blades cannot project and the rotational force of the rotor is significantly reduced, the startability of the air motor is reduced, and the startability of the internal combustion engine is poor.

In view of such a point, an object of the present invention is to provide an air motor for a starting device of an internal combustion engine, which can start with good startability and can reliably start the internal combustion engine.

(Means for Solving the Problems) The present invention is an air motor for a starter of an internal combustion engine, which is rotated by compressed air supplied from an air source through a main air supply passage, and is fitted into a cylindrical casing. An inner cylinder having an eccentric hollow hole, disk-shaped end plates fixed to both ends of the inner cylinder, and flat plates in a plurality of radially formed slots rotatably supported in the eccentric hollow hole. -Shaped movable blade is formed in the central portion of the inner surface of at least one of the end plate and the rotor into which the movable blade is inserted in and out freely, and opens in an arc shape over the extrusion range of the movable blade, and the bottom of the slot. And an exhaust groove formed in the center of the inner surface of at least one of the end plates, opening in an arc shape over the pushing range of the movable blade, and communicating with the bottom of the slot, and the main supply groove. In the airway An opening / closing means that is interposed and is opened by compressed air supplied through the main air supply passage, and is formed in the center of the inner surface of at least one of the end plates, one end of which is the air supply groove, and the other end of which is the inner cylinder. And an air supply hole that communicates with the main air supply passage on the upstream side of the opening / closing means via an axial direction, and at the center of the inner surface of at least one of the end plates. One end communicates with the exhaust groove and the other end. And an exhaust hole open to the atmosphere.

(Operation) Before supplying compressed air to the air motor, a part of the compressed air from the air source reaches the air supply groove via the air supply holes of the inner cylinder and the end plate, and is positioned within the extrusion range of the movable blade from there. Divide into the bottom of the slot. As a result, the movable blade in the extrusion range receives compressed air on the bottom surface and projects from the slot, and the tip surface is in contact with the wall surface of the eccentric hollow hole to maintain airtightness.

Then, the opening / closing means is opened by the compressed air from the air source, and the compressed air is supplied to the air motor. As a result, the air motor starts with good startability.

On the other hand, when the movable blade reaches the pushing range, its slot bottom communicates with the exhaust groove, and the compressed air acting on the bottom surface of the movable blade is discharged from the exhaust groove into the atmosphere via the exhaust hole.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, reference numeral 1 denotes a starter for an internal combustion engine, which is provided with an air motor 3, an opening / closing means 4, and a transmission 5 inside a casing 2.

The casing 2 is a flange portion 6a of the front casing 6.
The rear casing 7 is integrally connected to the. The front casing 6 is a tubular body having a hollow hole 6b, and a front cover 8 is fixedly mounted on the front end surface. The rear casing 7 is a tubular body having two hollow holes 7a and 7b at the top and bottom. Rear covers 9 and 10 are fixed to the rear end surfaces of these hollow holes, respectively.

In the air motor 3, the inner cylinder 11 is fitted in the hollow hole 7a of the rear casing 7, and the end plates are provided at both front and rear ends of the inner cylinder 11.
12 and 13 are fixed respectively, and the rotor body 14a of the rotor 14 is rotatably supported in the eccentric hollow hole 11a of the inner cylinder 11.

Each of the end plates 12 and 13 has boss portions 12b and 13b at the center of the outer surface of the disk portions 12a and 13a, and the eccentric hollow hole 11a.
Both ends are sealed.

The rotor 14 has rotor shafts 14b and 14c protruding from both front and rear end surfaces of a cylindrical rotor body 14a.
A plurality of slots 14d radially formed on the outer peripheral surface of the
A movable blade 15 having a flat plate shape is inserted thereinto so as to be freely inserted and removed, and rotor shafts 14b and 14c are rotatably supported by boss portions 12b and 13b of end plates 12 and 13 via bearings 16, respectively. The pinion 17a of the speed reducing means 17 is fixedly provided at the shaft end of the front rotor shaft 14b.

The disk parts 12a, 13a of the end plates 12, 13 have slots
Air supply grooves 12c, 13c communicating with the bottom of 14d are formed in the center of the inner surface, and air supply holes 12d, 13d having one ends communicating with the air supply grooves 12c, 13c are formed in the radial direction. Further, in the disc portion 12a, an exhaust groove 12e communicating with the bottom of the slot 14d is formed on the opposite side of the air supply groove 12c at the center of the inner surface, and one end thereof has an exhaust hole 12f communicating with the exhaust groove 12e.
Are drilled in the radial direction.

Each of the air supply grooves 12c and 13c is opened in an arc shape over the pushing range of the movable blade 15, and the exhaust groove 12e is opened in an arc shape over the pushing range of the movable blade 15. The other end of each air supply hole 12d, 13d communicates with both ends of an air supply hole 11b axially bored in the inner cylinder 11, and the other end of the exhaust hole 12f is connected to a main exhaust passage 7c formed in the rear casing 7. One end of the communicating main exhaust passage 7c is opened in the eccentric hollow hole 11a over the pushing range of the movable blade 15, and the other end is open to the atmosphere via the main exhaust port 7d.

The opening / closing means 4 is provided in the hollow hole 7b of the rear casing 7,
The support block 18 and the sleeve 19 are fitted and
The valve portion 20a of the slide valve 20 is fitted in the hollow hole 19a of 19 so as to be slidable in the axial direction. The support block 18 has a central hole 18a communicating with the air passage 10a formed in the rear cover 10, and seals the rear end of the hollow hole 7b. Hollow hole 19a of sleeve 19
Two O-rings 21 are fitted to the front end of the valve to maintain airtightness between the valve and the valve section 20a.

The slide valve 20 has a valve rod 20 on both front and rear end surfaces of a cylindrical valve portion 20a.
b and 20c are protruding, and the valve stem 20c is a support block
It is fitted in the center hole 18a of 18 so as to be slidable in the axial direction. The valve portion 20a has a tapered portion 20d formed on the outer peripheral surface of the rear end portion thereof, and has a gap A between the rear end surface and the front end surface of the support block 18.
Are formed. One end of the rear casing 7 is opened in the eccentric hollow hole 11a over the extrusion range of the movable blade 15,
The main air supply passage 7e whose other end communicates with the hollow hole 19a of the sleeve 19
And a main air supply passage 7g that communicates the hollow hole 19a with the main air supply port 7f.
Is formed, the middle part of the main air supply passage 7g and the inner cylinder
An air supply hole 7h communicating with the middle portion of the air supply hole 11b of 11 is provided.

The transmission 5 is a bearing in which the starting rotary shaft 22 is fitted in the front cover 8 in the hollow hole 6b of the front casing 6.
It is rotatably supported and axially movable by two bearings 24 fitted in the hollow hole 6b.

A starting pinion 25 is fixed to the front end of the starting rotary shaft 22, and a compression spring 28 is interposed between the intermediate flange 22a and the front cover 8 via a thrust bearing 26 and a spring seat 27. The one-way clutch 29 is slidably fitted in the spline 22b formed on the outer peripheral surface of the rear end portion in the axial direction, and the valve rod 20b of the sliding valve 20 is inserted into the center hole 22c formed in the rear end surface. It is loosely fitted, and a thrust bearing 30 is provided between the rear end face and the front end face of the valve portion 20a of the slide valve 20.

The compression spring 28 biases the starting rotary shaft 22 in a direction (leftward direction in FIG. 1) in which the meshing of the starting pinion 25 is released. The one-way clutch 29 has a gear 17b that is meshed with the pinion 17a of the speed reducer 17 and is fixedly mounted on the outer peripheral surface of the one-way clutch 29.
It is rotatably supported by 24 and a bearing 31 fitted in the hollow hole 7b of the rear casing 7.

Next, the operation of the starting device 1 will be described.

First, compressed air from the air source is supplied from the main air supply port 7f to the main air supply passage 7g.
When supplied into the inside, a part of the compressed air is diverted into the air supply hole 7h, and the air supply groove 11c and the air supply groove 12c via the air supply holes 12d and 13d.
13c, from which the flow splits into the bottom of approximately half of the slots 14d located in the extrusion range of the movable blade 15. The movable blades 15 in the extrusion range are slotted by receiving compressed air on the bottom surface.
It projects from 14d, and its tip end surface contacts the wall surface of the eccentric hollow hole 11a to maintain airtightness.

Next, another part of the compressed air is branched into the air passage 10a to reach the central hole 18a, and the slide valve 20 is moved or advanced in the right direction in FIG. 1 via the valve rod 20c. The valve unit 20a connects the starting rotary shaft 22 to the compression spring 28 via the thrust bearing 30.
The air gap A is communicated with the main air supply passages 7g, 7e through the taper portion 20d while advancing against the main air supply passages 7g, 7e.
Half open. A part of the compressed air in the rest is the main air supply passage 7g, 7
Movable blades 15 adjacent to each other in the extrusion range via e
Is supplied to the rotor body 14a to slowly rotate the rotor body 14a. The rotor 14 slowly rotates the starting rotary shaft 22 via the speed reducing means 17 and the one-way clutch 29. As a result, the starting pinion 25
Partially meshes with a starting gear (not shown) of the internal combustion engine.
Subsequently, the sliding valve 20 advances to completely engage the starting pinion 25 with the starting gear and fully open the main air supply passages 7g, 7e. As a result, all the remaining compressed air is supplied to the possible vanes 15, increasing the rotational torque and speed of the rotor 14 and speeding up the internal combustion engine.

When the movable blade 15 reaches the pushing range by the rotation, the bottom of the slot 14d communicates with the exhaust groove 12e, and the movable blade 15 moves.
The compressed air acting on the bottom surface of the
It is discharged into the atmosphere via 2f, the main exhaust passage 7c and the main exhaust port 7d.

Therefore, the movable blade 15 has its tip end surface pressed by the wall surface of the eccentric hollow hole 11a and gradually pushed into the slot 14d, and the compressed air between the movable blades 15 also passes through the main exhaust passage 7c and the main exhaust port 7d. And then released into the atmosphere.

In this way, when the internal combustion engine is started, the supply of compressed air is stopped, and the compressed air in the center hole 18a and the air passage 10a is discharged into the atmosphere. The compression spring 28 retracts the sliding valve 20 together with the starting rotary shaft 22 to the original position by the restoring force, releases the meshing of the starting pinion 25, and at the same time, the main supply passages 7g and 7e.
The communication with is cut off. At that time, one-way clutch
29 prevents the internal combustion engine from driving the starting rotary shaft 22 and causing the speed of the rotor 14 to become excessively high.

(Effects of the Invention) According to the present invention, as described above, since compressed air acts on the bottom of the movable blade through the air supply groove, the movable blade completely projects from the slot, and the movable blade tip surface and the eccentric hollow hole. The airtightness between the wall surface and the wall surface is completely and surely maintained, and the internal combustion engine is reliably started.

In particular, since the compressed air is introduced into the main air supply passage from the upstream side of the opening / closing means of the main air supply passage (from the air source), there will be no shortage of air volume, and the compressed air will not be discharged before the air motor is started. By operating, the air motor is started in a state where the airtightness between the tip surface of the movable blade and the wall surface of the eccentric hollow hole is completely and surely maintained, and the start of the air motor becomes more reliable.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a starting device for an internal combustion engine equipped with an air motor according to the present invention, and FIG. 2 is II- of FIG.
It is a II sectional view. 1 ... Starter, 2 ... Casing, 3 ... Air motor, 4 ... Opening / closing means, 7e, 7g ... Main air supply passage, 11 ... Inner cylinder, 11a ... Eccentric hollow hole, 11b ... Air supply hole , 12,13 …… End plate, 12c, 13c …… Air supply groove, 12d, 13d …… Air supply hole, 12e …… Exhaust groove, 12f …… Exhaust hole, 14 …… Rotor, 14d
…… Slot, 15 …… Movable blade

Claims (1)

[Claims] 1. An air motor for a starting device of an internal combustion engine, which is rotated by compressed air supplied from an air source through a main air supply passage, the inner motor having an eccentric hollow hole fitted in a cylindrical casing. A disk-shaped end plate fixed to both ends of the inner cylinder, and a movable blade in a flat plate freely inserted into and retracted from a plurality of radially formed slots rotatably supported in the eccentric hollow hole. A cylindrical rotor inserted, and formed in the central portion of the inner surface of at least one of the end plates, opening in an arc shape over the extrusion range of the movable blade,
An air supply groove that communicates with the bottom of the slot, and is formed in the center of the inner surface of at least one of the end plates, and opens in an arc shape over the pushing range of the movable blade,
An exhaust groove communicating with the bottom of the slot, an opening / closing means provided in the main air supply passage and opened by compressed air supplied through the main air supply passage, and a central portion of an inner surface of at least one of the end plates. At least one of the end plate and an air supply hole formed at one end and communicating at the other end with the main air supply passage on the upstream side of the opening / closing means via the inner cylinder in the axial direction. An air motor for a starting device of an internal combustion engine, comprising: an exhaust hole which is formed in a central portion of an inner surface and has one end communicating with an exhaust groove and the other end opened to the atmosphere.