Under the background of green and low-carbon economy going deep into all fields of society, based on building environmental protection, energy saving and maximum saving of building area and building projection height, the inorganic room elevator products have been comprehensively promoted and applied in recent years, becoming the mainstream elevator products in the market of small and high-rise buildings, and becoming the first choice of more and more developers as the public vertical transportation of buildings; however, Because the moving parts such as the main machine of the inorganic room elevator are installed in the hoistway, if the effective vibration isolation measures are not taken in the architectural design, structure and elevator installation, the large vibration and noise will often affect the living of the adjacent residents on the top floor, which once became an important factor that puzzled and affected the selection of elevator model for developers. In order to prevent the non machine room elevator product technology from being affected by non professional reasons and the lack of technology and knowledge in noise reduction prevention at the early stage of the development of the non machine room elevator. This paper will analyze the advantages and disadvantages of small machine room elevators and inorganic room elevators in noise prevention and control from the perspective of acoustics and vibration transmission research based on our company's many years of experience in elevator noise reduction practice and management, so as to provide reference for elevator manufacturers and users

1、 Elevator noise prevention technology:

1. The key to the influence of the elevator running noise on the indoor is the architectural design of the main bearing wall of the elevator shaft or machine room and the effective implementation of the elevator vibration reduction measures.

Based on the experience analysis of many years' elevator noise reduction cases, the elevator running noise is mainly caused by the transmission of the elevator running vibration through the shaft wall or the bearing wall structure of the machine room, so the design of the building structure is one of the important and effective measures to prevent the elevator noise. In the architectural design stage, if the structure of the shaft wall and the household wall can be separated in the architectural design, it will play a very positive role in reducing the impact of the elevator operation noise; if it can not be avoided in the design, it can only be effectively solved through the later elevator vibration reduction measures, such as the patented technology for vibration reduction and noise reduction of the elevator in the small machine room developed by our company and the vibration reduction and noise reduction technology of the elevator in the inorganic room The patented technology of the system (attached with the case picture of Xizi Otis Elevator noise reduction treated by our company) can comprehensively solve the problem of elevator operation noise. After treatment, the indoor noise can ensure that it meets the current national standard requirements, and the elevator operation noise can not be heard indoors.

2. There is no significant difference between the elevator with machine room and the elevator with small machine room (the elevator without effective vibration control) from the acoustic point of view and the size of noise source.

In fact, the small machine room elevator and the inorganic room elevator are driven by the same permanent magnet synchronous motor. The mechanical design and structure are basically the same. The difference in their own properties is only that "the inorganic room elevator is to put the main machine room in the shaft under the floor", and "the small machine room puts the main machine in the machine room on the floor". Therefore, from the acoustic point of view (in terms of the size of the noise source), the noise of the elevator in the inorganic room and the elevator in the small room is not very different, and the impact on the indoor noise is not very different. According to the case analysis of our treatment, the elevator in the same small machine room of the same building structure without considering the noise reduction measures of the elevator will have the same problem that the running vibration of the elevator will affect the indoor noise of the top floor residents. Therefore, according to our professional opinion, elevators without machine room or with machine room can be selected in the building according to the needs of developers or architectural design. Only from the aspect of architectural design and vibration reduction measures, it is unnecessary to deliberately choose elevators with or without machine room in order to consider the prevention and control of elevator noise.

3. One of the main reasons for the great impact on the indoor noise is the reverse rope wheel of the elevator. Attention should be paid to the design and installation of the reverse rope wheel during the installation of the elevator.

Considering from the angle of tension force distance, the permanent magnet synchronous elevator adopts the multiple steel wire rope to lift the force design, so the reverse rope wheel should be added to the lift car and the car roof side. However, in order to avoid the friction between the reverse rope sheave and the steel wire rope and the superposition of the car running vibration affecting the household room, from the perspective of elevator noise reduction, our company suggests that the car side should adopt the reverse rope sheave design of the bearing beam on the car top (the reverse rope sheave is made of high fiber material or the reverse rope sheave itself can increase the rubber reduction best), and the double reverse rope sheave design structure at the car bottom side should be avoided. Because according to the experience of noise reduction of several non machine room elevators contacted by our company, the double reverse rope sheaves on the bottom side of the car will cause great vibration superposition and affect the room (especially when the elevator is under downward force). For example, the Tongo individual inorganic room elevator series and Xun ○ 300p inorganic room elevator contacted by our company at present, because of the double reverse rope sheave structure of the car bottom, its guide rail noise and reverse rope sheave vibration superposition rear The elevator noise in each building can exceed 40 dB. Therefore, in addition to the impact of the running noise of the elevator main engine, the vibration and sound transmission caused by the reverse rope wheel needs our manufacturer's first consideration, which must be avoided during the design and installation of the elevator.

2、 The cost of elevator noise control

1. As far as the price of elevator noise reduction system is concerned, the cost of elevator noise reduction in inorganic room is slightly higher.

As far as the price of our elevator noise reduction system is concerned, the vibration control of a series of components such as speed limiter and elevator control electrical parts in the shaft is required for noise reduction of the inorganic room elevator, so the cost and price of noise reduction is slightly higher than that of the elevator in the small machine room; in addition, as far as the noise reduction construction is concerned, the construction difficulty is also slightly higher because all noise reduction operations are in the shaft and platform construction is required 。 According to our current market promotion price, small machine room