JPH0767255B2 - Hermetic protector for electric compressor - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a heat deformable body made of a metal, such as a bimetal, whose shape is changed by a temperature change in order to protect an electric motor from overload in a hermetic electric compressor. The present invention relates to a protector for a hermetic electric compressor that drives a movable contact to open / close a current flowing in a motor between a fixed contact and the movable contact.

[Background technology]

Conventionally, this type of protector for an electric compressor is attached to the outside or inside of a closed container in which the electric motor and the compressor are housed, and the electric current supplied to the electric motor is detected by detecting an abnormal electric current or an abnormal temperature of the electric motor. To protect the windings of the motor from overheating and automatically return to supply current to the motor.If there is no abnormality in the motor, continue operation. Therefore, in order to improve its protection performance, the number of internal protectors to be installed inside is increasing more recently than the external protectors to be installed outside the closed container. In this case, the internal protector has heretofore been fixed by a method of embedding it in the stator winding of the electric motor or by a thread that binds the winding closely to bind the winding. On the other hand, due to the miniaturization of the hermetic electric compressor itself, the residual space inside the hermetic container that houses the electric motor and compressor becomes narrower, and the problem of securing space on the stator winding for mounting the protector and the number of installation steps are possible. It is desired to improve the economic efficiency by omitting it.

[Outline of Invention]

The protector for the hermetic electric compressor of the present invention has an electric motor and a compressor housed in a hermetic container, and a refrigerant gas compressed by being driven by the electric motor is provided through the upper surface of the hermetic container. In a hermetic electric compressor configured to deliver from a discharge pipe, the motor winding on the inner surface of the upper wall of the hermetic container that can correlate well with the abnormal temperature of the motor when the motor abnormally generates heat due to excessive load etc. Attach the airtight terminal to connect the power supply to the wire, and store and hold the receptacle that is fixed to the multiple conductive pins of the airtight terminal with the socket made of electrically insulating material, and
One of the plurality of receptacles that is electrically conductively fixed to one conductive terminal of the protector is held by the socket, and the other conductive terminal of the internal protector is connected to one end of the winding of the electric motor with a lead wire. The other end of the motor winding is connected to another receptacle with a lead wire, and each receptacle is connected to the conductive pin of the airtight terminal to connect the motor from the external power source to the motor in the sealed container via the airtight terminal. It is intended to supply electric current and surely protect the electric motor at the time of abnormality by the protector.

Example of Invention

FIG. 1 is a longitudinal sectional view of the entire hermetic electric compressor according to an embodiment of the present invention. A hermetic container 10 is composed of a robust iron container part 11 and a lid part 12. In the container portion 11, a compressor P is arranged near the lower end of a rotary shaft S fixed to the rotor R of the electric motor, and is fixed below the closed container 10 at the outer periphery PO portion thereof. An electric motor stator F, which is arranged so as to surround the rotor R, has its outer periphery fixed from the center of the container portion 11 to the vicinity of the opening end E. The stator winding W is electrically insulated and wound around the stator. Although the refrigerant gas such as Freon is not shown, the lubricating oil O is shown in the lower portion of the closed container 10.

The lead wires 14 and 15 of the winding W of the motor stator F are connected to a receptacle held in a socket 20 made of phenolic resin or the like, as shown in FIGS. 2 to 4, respectively. The wires 14 and 15 are housed and held with the receptacles 14A and 15A insulated from each other by the partition wall 23 of the socket 20. Lead wire 13 is one conductive terminal of internal protector 30
Connected to 32. The conductive terminal 32 is provided with a metal outer box 31 of the protector 30 via an electrically insulating filler material 33 such as glass.
It is fixed to. As is well known, the protector 30 drives a movable contact with a metal such as a bimetal that deforms due to a change in temperature to open and close an electric current flowing between the fixed contact and the electric motor. The contacts of the protector are closed when the heat-deformable metal is at a normal temperature, and the one conductive terminal 32 and the outer casing 31, which is the other conductive terminal, are electrically closed by the contacts inside. The receptacle 13A is electrically conductively fixed to the outer case 31 of the protector 30 by a method such as welding as shown in FIG.
And are insulated and stored in the socket 20.

The outer shell 21 of the socket 20 is provided with three holes 21A, 21B and 21C, and the conductive pins 16A, 16B and 16C of the airtight terminal 16 sealed to the lid portion 12 of the airtight container 10 are hermetically sealed. The parts protruding inside (the parts hidden behind the socket 20 in FIG. 1 and not visible) are the three holes 21A of the outer shell 21 of the socket 20, respectively.
・ It penetrates 21B and 21C and is electrically connected and held with the receptacle. In the case of a single-phase induction motor, the winding W of the motor stator F is composed of a main winding and an auxiliary winding. One end of the main winding is connected to the receptacle 14A by the lead wire 14, and one end of the auxiliary winding is connected to the lead wire. The wires 15 are connected to the receptacle 15A, respectively, and the other ends of the main winding and the auxiliary winding are commonly connected to the receptacle 13A by the lead wire 13. Further, a discharge pipe 17 to which the compressed refrigerant gas is delivered is airtightly fixed to the lid portion 12 of the closed container 10.

When the stator winding of the electric motor is connected to the power source through the conductive pins 16A, 16B and 16C of the airtight terminal 16 and the current is applied, the rotor R rotates and drives the compressor P. By the compressor P, the refrigerant gas is sent out from the discharge pipe through the gap between the stator F of the electric motor and the airtight container 10 and the gap between the stator F and the rotor R in the axial direction, and a condenser, an evaporator or the like not shown. In the hermetic electric compressor, the refrigerant gas thus compressed flows through the electric motor in the axial direction and is discharged from the discharge pipe provided on the upper surface of the hermetic container. , If the protector is installed on the upper surface of the closed container, the heat generated by the electric motor is transmitted well by the refrigerant gas, and it is almost comparable to the conventional method of binding the protector on the stator winding, and the protection performance against abnormalities of the electric motor is obtained. Can be done. Incidentally, if a vent hole 24 is provided in a part of the socket 20 in which the protector 30 is housed so that the refrigerant gas flows in good contact with the protector 30, as shown in FIG. 4, the protection performance can be further improved. .

〔The invention's effect〕

The protector for the hermetic electric compressor of the present invention described above is
Holds the internal protector and receptacle directly conductively fixed to a socket made of an insulating material that holds multiple receptacles that are fitted to the conductive pins of the airtight terminal required for power supply to the electric motor I made it so
The socket only needs to be a little larger, which saves a lot of work compared to the conventional method of binding to the winding of the electric motor, and also considers the extra space of the electric motor and enlarges the sealed container. It has excellent effects such as not requiring materials.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing a hermetic electric compressor according to an embodiment of the present invention. FIG. 2 shows a plan view in which a part of the outer shell of the socket holding the internal protector is removed. FIG. 3 is a side view seen in the direction of the arrow in FIG.
FIG. 4 is a perspective outline view of the socket shown in FIGS. 2 and 3. 10 …… Airtight container, 13A ・ 14A ・ 15A …… Receptacle, 16
...... Airtight terminal, 16A / 16B / 16C ... Conductive pin, 17 ... Discharge pipe, 20 ... Socket, 30 ... Protector, F ... Motor stator, P ... Compressor, R ... Motor rotor , S ……
Rotating shaft, W ... Motor winding.

 ─────────────────────────────────────────────────── ─── Continuation of the front page Judgment panel Judge Chief Yoshio Mizutani Judge Judge Tadayuki Watanabe Judge Mitsutaka Itabashi (56) References JP-A-56-107990 (JP, A) JP-A-55-56323 (JP, A) ) Actually open 60-95183 (JP, U) Actually open 60-114574 (JP, U)

Claims (2)

[Claims] 1. A hermetic electric compressor in which an electric motor and a compressor are housed in a hermetic container, and a compressed refrigerant gas is discharged from a discharge pipe provided through the upper surface of the hermetic container. A protector having a metal container having good thermal conductivity and electrically conductively fixed to the metal container a receptacle connected to a conductive pin of an airtight terminal provided on the top of the sealed container, and a protector provided on the upper face of the sealed container. It has a plurality of receptacles for connecting the motor windings to the conductive pins of the airtight terminal, and a socket for accommodating the protector and each receptacle in substantially the same plane so that the whole becomes thin, and the socket is the same as the protector and the receptacle. The socket that holds the protector and the receptacle is equipped with a partition for inserting and holding from the direction and electrically insulating each other. By being attached to the inside of the container, the conductive pin and each of the receptacles are electrically connected, and the protector and the receptacle are arranged so that heat exchange between the protector and the refrigerant gas discharged from the compressor can be performed well. A protector for a closed electric compressor. 2. The sealed type according to claim 1, wherein the socket is provided with a vent hole so that at least a part of the metal container of the protector is exposed to the refrigerant gas in the sealed container. Protector for electric compressor.