JPS61160587A - Motor compressor - Google Patents

Abstract

PURPOSE:To make an enclosed compressure preventable from vibrating, by installing a blind hole in the underside of a stator, while fitting an upper end of a spring attached to a wall surface inside a vessel, in this blind hole. CONSTITUTION:Plural blind holes 3 are formed in the underside of a stator 2, while an upper end of a spring 7 attached to an inner wall surface of an enclosed vessel 4 is fitted in this blind hole 3. A supporting point in the stator 2 is installed over a range from the center of gravity of an inner device to an upper end face of the stator 2 so that it is well resistible to both static and dynamic external forces.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a motor compressor, and more particularly to a motor compressor having improved means for supporting its internal equipment.

[Technical background of the invention and its problems] In a conventional motor compressor, its internal device is supported as follows. One is to suspend and support the internal device from the compressor casing with a spring, and the other is to attach a spring to the lower end of the stator of the internal device and support it on the compressor casing via this. Met.

According to the former supporting means, since the internal device can be supported near the center of gravity of the internal device, the occurrence of imaging can be suppressed. However, due to the structure of the support part, space is required within the housing.
It has been difficult to downsize the housing and therefore the motor compressor. On the other hand, the latter support means does not require a large space within the housing, and the compressor can be made smaller. However, since the center of gravity of the internal device is located above the support position, coupled vibrations are likely to occur, resulting in increased vibration of the motor compressor.

[Object of the Invention] The present invention has been made based on the above circumstances, and an object of the present invention is to obtain a motor compressor that can suppress vibrations of an internal device and can be downsized.

[Summary of the Invention] The motor compressor of the present invention has an internal device elastically supported by a spring in a housing, in which an upper end of the spring elastically installed between the bottom surface of the housing and the stator,
The stator is characterized in that it is supported by the upper bottom surface of a blind hole provided on the lower surface of the stator.

[Embodiment of the Invention] FIG. 1 shows an embodiment of the invention. In this figure, blind holes 3 perpendicular to the lower surface are provided at the four corners of the lower surface of the stator 2 of the internal device 1 of the motor compressor, and the bottom surface of the blind holes 3 is provided with a projection provided on the inner bottom surface of the casing 4. A protrusion 6 similar to 5 is provided. The internal device 1 is supported on the inner bottom surface of the housing via a spring 7 whose both ends are engaged with respective projections 5,6. FIG. 2 is a block diagram of the vibration system of the motor compressor of the present invention having the above configuration. In this figure, F is the external force, G is the center of gravity of the internal device, kl is the horizontal spring constant of the spring 7, and kg is the vertical spring constant. constant, K is the rotational spring constant, C is the vertical distance from the center of gravity to the support point of the stator 1, 2a is the width of the internal device, 2
b is its height.

Below, the motor compressor of the present invention having the above configuration will be discussed from a vibrational perspective. First, the external forces that act on the motor compressor can be broadly classified into instantaneous external forces that act on the motor compressor when it starts or stops, and dynamic external forces that act on the motor compressor during steady operation. In order to reduce the force transmitted to the casing when receiving these external forces, the internal device is normally supported elastically with respect to the casing. Since the external force that acts upon starting and stopping is not a periodic force, it can be treated as a static external force. Assuming this external force is F, the equation for the balance of the vibration system above is: F-2: 1(X - eC,) =O Fb +2: +xC-2: 7θc" (1)
+2 to 2θo2 #-2 to θ = 02 Here, X is the displacement of the center of gravity in the x direction, y is the displacement in the y direction, and θ is the displacement in the rotational direction.

θ is expressed by the following equation (2) derived from equation (1).

θ−F (b + c)/2 (K+kz a)・
・・・・・・・・・・・・・・・(2) From equation (2), when the internal device receives a static external force F, in order not to cause rotational displacement, c = -b. That is, the support point of the support means may be provided on the line of action of the external force F.

In addition, the equation of motion when receiving a dynamic external force is the following equation (3)
It is expressed in

m'x = F - 2 to 1 (x - eC) [j = Fb + 2klXC - 2ktθC2...
...(3) +2 to 2θoF -2kθ Here, m is the mass of the internal device, and ■ is its moment of inertia.

From this equation, in order for the displacements that occur in the directions of special degrees of freedom that are subjected to dynamic external forces to be uncoupled, that is, to be mutually independent, c = Q, that is, the support point of the support means is on the horizontal plane passing through the center of gravity. All you have to do is set it up.

As is clear from the above, when considering static balance with respect to the external force acting on the internal device, the blind hole 3 is provided at a position close to the line of action of the external force, and when considering the dynamic coupling of forces, The support point may be provided as close as possible to a horizontal plane passing through the center of gravity.

After all, if the support point of the stator 2 is provided between the center of gravity of the internal device 1 and the upper surface of the stator 2, both static and dynamic external forces can be well coped with.

[Effects of the Invention] As is clear from the above, in the present invention, the stator of the internal device is provided with a blind hole, and the support point of the stator relative to the casing is provided in the blind hole, so that the center of gravity of the internal device is Even if the support point is selected at a position that can adequately handle both dynamic and static external forces, the motor compressor can be made smaller without requiring a large space inside the housing. It is.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway perspective view of one embodiment of the present invention;
The figure is a block diagram of the vibration system.

Claims (2)

[Claims] (1) In a device having an internal device elastically supported by a spring in the housing, the upper end of the spring elastically installed between the bottom surface of the housing and the stator is connected to the upper bottom surface of the blind hole provided on the lower surface of the stator. A motor compressor characterized by being supported. (2) The motor compressor according to claim 1, wherein a support point for the upper end of the spring is provided between the center of gravity of the internal device and the upper end surface of the stator.