Power-dissipation-free and energy-saving type start protector of single phase AC motor

Abstract

The invention provides a power-dissipation-free and energy-saving type start protector of a single phase AC motor and belongs to the technical field of refrigeration compressors. The power-dissipation-free and energy-saving type start protector comprises a shell, a shell cover, an overload protector, a power-dissipation-free starter and an external terminal mechanism. The shell is provided with an overload protector seat, a power-dissipation-free starter accommodation cavity, an external terminal mechanism cavity and a start controller accommodation cavity. The shell cover is provided with a first three-terminal jack and a second three-terminal jack. The overload protector is arranged in an overload protector accommodation cavity. The power-dissipation-free starter comprises a power-dissipation-free starter body and a start controller. The external terminal mechanism is matched with the external terminal mechanism cavity. The start protector is characterized in that the external terminal mechanism cavity comprises a first insertion cavity, a second insertion cavity and a third insertion cavity, the second insertion cavity is formed in the left side of the shell, and the bottom wall of the second insertion cavity is provided with a second shell insertion groove; the first insertion cavity and the third insertion cavity are formed in the right side of the shell, a first shell insertion groove is formed in the bottom wall of the first insertion cavity, and a third shell insertion groove is formed in the bottom wall of the third insertion cavity; the external terminal mechanism comprises a first insertion piece and a second insertion piece, the first insertion piece is matched with the second shell insertion groove in an inserted mode, and the second insertion piece is matched with the first shell insertion groove in an inserted mode.

Description

technical field [0001] The invention belongs to the technical field of refrigeration compressors, and in particular relates to a no-power consumption and energy-saving single-phase AC motor starter protector, which is used for starting and protecting the refrigeration compressor motor. Background technique [0002] Since the common refrigeration compressor motor is a low-power single-phase AC motor, a starter is required to assist in starting, and when the compressor enters a normal operating state, it needs to be protected by an overload protector. Specifically, the overload protector The device ensures that the refrigeration compressor is disconnected from the power supply when it is overloaded during operation, so as to prevent the compressor from overheating and causing damage. [0003] In the past, the starter and overload protector of the refrigeration compressor were usually designed as a split structure, that is, the starter and the overload protector were connected ...

AI Technical Summary

Problems solved by technology

[0007] First of all, as far as the housing is concerned, due to the scattered and disorderly distribution of the external terminal mechanism (also known as the blade mechanism or pin mechanism in the industry) on the housing, it is difficult to reduce the volume of the housing, so that it is impossible to reduce the impact on the refrigeration compressor. Occupies space, and also affects compact structure, convenient and efficient assembly, saving material consumption and reliability in use

In addition, since it is necessary to form six baffles for blocking the pins (including grounding pins, N pins and L pins) on the shell cover and the side facing the housing, and four anti-movement limit stops to prevent the pins from moving Protrusion and five supporting flanges for supporting pins (for details, please refer to paragraph 2 on page 5 to paragraph 1 on page 6 of the specification of this patent), thus not only significantly increasing the complexity of the shell structure, but also affecting The installation efficiency of the pins; due to the unreasonable structure of the shell cover itself, the pins (ie ground pins, N pins and L pins) must be assembled before the shell cover is assembled with the shell, That is to say, the pins are first inserted into the corresponding pin slots (that is, pin holes) preset on the cover, and then the cover and the pins are matched with the shell, so the assembly efficiency will be seriously affected, because the pins are pre-installed. Installing on the case cover will cause interference when the case cover is mated with the case, and the stability of the pins is also difficult to guarantee, and there is a risk of deflection and looseness

[0008] Secondly, as far as the starter is concerned, one, although contacting both sides of the bottom of the PTC thermistor with the top protrusion can significantly reduce the PTC thermistor in the case. The supporting area in the cavity can significantly reduce the volume of the positive temperature coefficient thermistor, for example, the weight is reduced from 35-40g to 15-16g, but because the circumferential side edge of the positive temperature coefficient thermistor still needs It is in contact with the wall of the positive temperature coefficient thermistor cavity in a large area, so it is not enough to reflect the ultimate energy-saving effect. The specific performance is that the volume of the positive temperature coefficient thermistor is still relatively large, and the weight (15-16g) still biased

Theoretically speaking, forming a support wall on the corresponding cavity wall of the positive temperature coefficient thermistor cavity and forming a protrusion on the support wall can make up for the above-mentioned deficiency, so that the volume of the positive temperature coefficient thermistor can be further reduced, The weight can be further reduced and the energy-saving effect can be reflected to the extreme degree, but repeated experiments by the applicant show that this idea is not advisable, because on the one hand, the aforementioned first and second pins and the positive temperature coefficient thermistor On the other hand, the installation of the starter is troublesome due to excessive occupation of the space of the PTC thermistor cavity; The structure of a pair of supporting walls on the upper part is relatively complicated, which leads to relatively complicated molds for manufacturing the shell; third, because the top protrusion is formed on the supporting walls, the bottom of the positive temperature coefficient thermistor, that is, the bottom surface, is in contact with the positive side. The distance between the cavity bottom of the temperature coefficient thermistor cavity is the sum of the height of the support wall and the height of the top protrusion, so the situation of excessively raising the positive temperature coefficient thermistor occurs, so that the positive temperature coefficient thermistor The positive temperature coefficient thermistor cavity protrudes from the upper part of the resistor, and the protruding part needs to be compensated by the raised cavity on the cover (the protruding part penetrates into the raised cavity), which increases the complexity of the cover on the one hand, On the other hand, the contact area between the positive temperature coefficient thermistor and the raised cavity is increased, and on the other hand, in order to ensure the first and second pins (the first pin is essentially the first contact piece, and the second pin is essentially the first contact piece) Two contact pieces, hereinafter the same) in the middle position corresponding to the two sides of the positive temperature coefficient thermistor to reliably hold the positive temperature coefficient thermistor and the position of the first and second pins must be moved upwards, so that the first 1. The support point between the second pin and the cavity wall of the positive temperature coefficient thermistor cavity (the part in contact with the cavity wall support) is moved to the upper cavity of the positive temperature coefficient thermistor cavity, so that the entire starter The effect of installation stability is affected, for example, the first and second pins are in danger of breaking free from the positive temperature coefficient thermistor cavity, which will cause the electrical contact between the first and second pins and the positive temperature coefficient thermistor to fail

Of course, by increasing the size of the housing in the height direction and thereby deepening the depth of the PTC thermistor cavity, the PTC thermistor can be located in the PTC thermistor cavity as a whole and can make up for the aforementioned disadvantages. Factors, but such a design will significantly increase the volume of the housing, that is, the problem of losing sight of the other; Fourth, because the first pin is in contact with the first pin reed on one side of the positive temperature coefficient thermistor, that is, the first contact Leaf reed (the patent is called the first spring) and the second prong is in contact with the surface of the other side of the positive temperature coefficient thermistor, that is, the second contact reed (the patent is called the second spring) All contact with the surface of the positive temperature coefficient thermistor in a straight line, that is, the first and second pin reeds are both horizontally parallel to each other and fully correspond to each other, so when the electric spark is generated, the positive temperature coefficient thermistor There will be many cracks, because the opposite sides are still elastically supported by the corresponding first and second pin reeds, and the cracked (cracked) part of the elastically supported positive temperature coefficient thermistor continues to be stable The ground is clamped in place while the remaining fragments scatter, so power continues through the resiliently supported remnants of the PTC thermistor, causing these remnants and their associated first and second The two-pin reeds melt each other, and then produce an alloy that exhibits a certain conductivity. As a result, an electrical short circuit is formed between the first and second prong reeds, which in turn further accelerates the abnormal heat generation. Generated, it is very likely to force further failure of the device, such as causing softening and deformation of the shell, etc.

[0009] In addition, as far as the overload protector is concerned, firstly, because the fixed seat only has a pin cavity for the spring piece and the pin (the patent is called the first pin) to accommodate, so when the spring plate and the pin are accommodated in the pin cavity, , the positioning effect of the fixing seat on the spring piece and the pin is fragile, so once there is a loose displacement, it will affect the electrical contact or disconnection effect between the moving contact on the spring piece and the static contact on the pin

Second, since the heating wire cavity formed on the fixing seat is only for accommodating the heating wire, it has no limiting effect on the heating wire, and there will be arching in the actual use process, which will affect the effect of the bimetal sheet and its overall contact

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