JPH02155446A - Pressure resistant explosionproof motor - Google Patents

Abstract

PURPOSE:To form a pressure resistant explosionproof type by introducing an outer cable into a motor case, connecting it to inner wirings by a connector, and providing an end cap to be detachably attached to an opening formed at the connector position of the case with a screw. CONSTITUTION:An outer cable 4 is introduced into a motor case 1 through an inlet 2, and connected to inner wirings 8 by a connector 3 made of a plug connector 3a and a receptacle connector 3b. An opening 1a is formed at a part in which the connector 3 of the motor case 1 is existed, and an end cap 9 is detachably attached. The disc 9a of the end cap 9 has antirotation holes 9d, 9e to be engaged with protrusions 10a, 10b of an exclusive use tool 10 to be rotated, thereby engaging a threaded part 9b with the threaded part 1b of the motor case 1. Thus, a pressure resistant explosionproof type motor which is facilitated for its maintenance and inspection is formed.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention provides a flameproof explosion-proof motor that enables disconnection and connection between external cables such as power cables and internal wiring of the motor at the site of use without danger. It's about structure.

(Prior art and problems to be solved) For motors used in painting sites where volatile paints are handled and other places where there is a high risk of gas explosion, the wall thickness is required to prevent explosions due to ignition caused by generated sparks. A hermetically sealed motor case is made of aluminum, iron casting, etc., and necessary equipment such as a motor rotation speed detector and a so-called resolver are housed in the case. In this case, when connecting external cables such as power supply cables to the motor section or taking out the rotation speed detector output, a terminal box with a sealed lid that can only be opened with a special tool owned by the maintenance manager is installed. In order to prevent any danger from occurring when the so-called indirect retractable type cable is connected to the terminal box or the power cable is accidentally disconnected from the terminal box, the external cable is connected to the motor case in a sealed motor case. A so-called direct lead-in method is adopted in which the motor is drawn into the motor and connected to the wiring inside the motor directly or via a connector. However, these have advantages and disadvantages as follows.

That is, in the indirect lead-in method, the external cable can be disconnected or connected by operating the terminal fitting inside the terminal box.

Therefore, by disconnecting the connection after cutting off the power without requiring prohibited soldering or solder melting work, the operation motor attached to a painting robot etc. can be easily and dangerously operated on site. There is an advantage that it can be replaced in case of failure. However, on the other hand, it has a terminal box, and since the terminal box has an electric circuit part that can cause an explosion, it is necessary to have a pressure-resistant and explosion-proof structure like the motor. For this reason, the wall thickness has to be the same as that of the sealed case, which forces the motor to be large and heavy, which is a major hindrance to use as a motor for painting robots, for example, which requires small size and light weight. There is a drawback.

On the other hand, the direct lead-in method does not require a terminal box, so it has the advantage of making the motor smaller and lighter. However, on the other hand, it is not possible to disconnect or connect the motor to an external cable, making it impossible to replace the motor on site. Of course, this can be done by removing the motor with the external cable connected, transporting it to a safe location away from the site, and disassembling the motor, but generally the external cable is fixed to a wall, The distance between the site of use and the non-hazardous area is usually 50 m or more. Therefore, it is not easy to remove the cable, so it is practically impossible.

(Objective of the Invention) The present invention provides a flameproof explosion-proof motor that is small and lightweight, and complies with the explosion-proof regulations for direct lead-in, which allows for easy connection and disconnection of external cables on-site.

(Means of the Invention for Solving the Problems) The present invention provides a flameproof explosion-proof motor of a direct lead-in type in which the external cable drawn into the sealed motor case and the internal wiring of the motor are connected by a connector. At least one end of the closed motor case is opened, and this opening can be closed and opened using an end cap that can be removed and installed only with a special tool.

Then, when replacing the motor, after cutting off the power, remove the end cap with a special tool and pull out the connector, allowing you to disconnect and connect the motor's internal wiring and external cables without performing prohibited soldering work. This makes it possible to reduce the size and weight of the motor, to replace the motor on-site, and to easily perform internal maintenance and inspection without risk. Next, the present invention will be explained in detail with reference to Examples.

(Example) Figures 1 (a) and (b) are cross-sectional explanatory views of essential parts showing an example of the present invention, and Figures 2 (a) and (b) are explanatory views of a special tool for attaching and removing the end cap. . In Fig. 1, (1) is the motor case, which has a circular opening (1a) at the end where the external cable and the motor internal wiring are connected, and an explosion-proof inner surface on the end. It has a threaded portion (1b) for attaching and detaching the end cap with a sufficient screw length. (
2) is an external cable entry port, which is formed integrally with the motor case (1), and a connector (3) is provided in the center of the port.
) has a through hole for pulling out an external cable (4) to which, for example, a plug connector (3a) is connected, and after insertion, it is sealed by a mechanism not shown. (5) is a morph part such as a stator single rotor housed in the motor case (1), (6) is its coil lead wire, (7) is a resolver for rotation detection, and (8) is its lead wire. And the coil lead wire (
6) Connect the solver lead wire (8) etc. to the connector (3)
It is connected to the other receptacle connector (3b), and is connected to the external cable (4) through a plug connection with the plug connector (3a). (9) is an end cap, which is a disc part (9a
), and has a threaded part (9b) for mounting/detaching on the outer circumferential surface having a sufficient screw length with the threaded part (1b) for mounting/detaching of the sealed case (1) so as to sufficiently withstand the explosion pressure. Hakamabe (9c
), and two (two or more as shown by dotted lines in the figure) cylindrical shapes provided on the same line on the disk surface at equal distances from the center of the disk (9a). , a polygonal columnar shape such as a triangular columnar shape or a quadrangular columnar shape (cylindrical shape in the figure), the end cap has a stopper hole (9d) (9e) for rotating the end cap. (9f) is a reinforced padded portion for reinforcement, and the stop hole (
9d) Disk portion (9c) created by providing (9c)
Reinforce the thin parts in a). This is a stop hole (9d)
It goes without saying that even if (9e) is provided, it may be omitted if explosion protection is sufficient.

Next, (10) is a special tool for rotating the end cap, which has a U-shaped cross section as shown in FIG. It has operating protrusions (10a) (10b) shaped to fit into the retaining holes (9d) (9e). Furthermore, a hexagonal nand portion (10c) for rotating the special tool (10) with a torque wrench, spanner, etc. is integrally provided at the center position between the protrusions (10a) and (10b). (
11) is a sealing O-ring which is inserted between the motor case (1) and the end cap as necessary.

In the present invention having the above configuration, the external cable and the motor internal wiring are disconnected and connected in the following manner. First, turn off the power, and then remove the operating protrusion (9) of the special tool.
a) Attach (9b) to the stopper hole (9d) of the end cap (9).
) (9e) and attach the special tool (10) to the end cap (9). Next, the hexagonal nut part (10c
) and rotate the end cap (9) in the direction of the arrow shown in Figure 3. (
1b). Then, one end of the motor case (1) is unblocked by the end cap (9) and opened, and the external cable (4) and the motor internal wiring (
6) Disconnect the connector (3) connecting between (8). Next, after pulling out the external cable (4) from the cable entry port (2), remove the motor from the painting robot, install the new motor that was brought to the site in advance, and replace the end cap (9). Remove the external cable with the connector using the same procedure as above (
4) into the motor through the inlet (2). After that, connect the connector (3b) connected to the motor internal wiring (6) (8) in advance to the connector (3a) connected to the external cable.
) and then screw the end camp (9) into the case (1) using the special tool (10) to complete the replacement.

(Effects of the Invention) As described above, in the present invention, external cables and internal wiring of the motor can be connected by operating the connector, eliminating the need for soldering work, which is prohibited as it is dangerous, and making it possible to connect and disconnect the connector. This can be done by removing the screw-in end cap provided on the case.

Therefore, it is possible to provide a pressure-resistant explosion-proof motor that allows easy replacement of the motor and inspection of the inside of the motor even in a dangerous location where there is a risk of explosion. In addition, a direct retraction method is adopted, and the end camp can be attached and detached using a special tool, making it possible to provide a pressure-resistant and explosion-proof motor that is small and lightweight and complies with explosion-proof regulations.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an embodiment of the present invention, FIG. 2 is an explanatory diagram of a special tool for attaching and detaching an end cap, and FIG. 3 is an explanatory diagram of an operation for attaching and detaching an end cap. (1)...Motor case, (1a)...Opening,
(1b)...Threaded part for attaching and removing the end cap, (2)
...External cable entry port, (3)...Connector, (3a)...Plug connector, (3b)...
・Receptor connector, (4)...external cable, (5)...motor section, (6)...its coil lead wire, (7)...rotation detection resolver, (8)...
...The lead wire, (9)...End cap,
(9a)...Disc part, (9b)...Screw part for attachment and detachment, (9c)...Hakama part, (9d) (9e)...
Stopper hole for end cap rotation operation, (9f)...Reinforcement padding part, (10)...Special tool for end cap rotation operation, (10a) (10b)...Protrusion for operation, (11) ... O-ring for sealing.

Claims (1)

[Claims] In a direct lead-in type flameproof explosion-proof motor in which an external cable is drawn into the motor case and connected to internal wiring of the motor through a connector, an opening having a threaded portion for attachment and detachment is provided at the connection point of the connector of the motor case. and the opening is formed so that it can be opened and closed by an end cap having a threaded part for mounting and dismounting that is threadedly connected to the threaded part for mounting and dismounting, and the opening and closing of the end cap is formed on the end cap surface. 1. A pressure-resistant and explosion-proof motor, characterized in that rotation is performed by a special tool having a plurality of rotary operation stop holes provided therein and a rotary operation protrusion inserted and fitted into the holes.