The reducer is a very important part of the mine hoist mechanical system, its function is to transmit motion and power (reduce speed, increase torque). Most of the mine hoists run continuously in three shifts, and there will be a small amount of shock during the operation. Starting and braking are very frequent, and they run in forward and reverse directions. The load type is medium shock load. According to the field test, the peak load when the mine hoist is started is generally 1.5 to 2 times the normal working load. The typical load change in one working cycle is shown in the figure below.

Hoist reducer use coefficient KA:

Single rope winding type: KA=1.6

Multi-rope friction type: KA=1.75

Root bending safety factor: SF≧1.5

Tooth contact safety factor: SH≧1.1

one

Selection requirements for hoist reducer

The reducer for hoist must meet the requirements of the following standards:

GB/T 20961-2007 Single-rope winding mine hoisting

GT/T 10599-2010 Multi-rope friction hoist

① The gear accuracy of the reducer shall comply with the provisions of GB/T 10095.1 and GB/T 10095.2.

② The cleanliness of the lubricating oil of the reducer should be no more than 3.4 amg (a is the sum of the center distances of all levels of the reducer, mm)

③ The temperature rise of the reducer bearing should not exceed 40℃, and the maximum temperature should not exceed 75℃. The temperature rise of lubricating oil in the box should not exceed 35℃.

④ There should be no oil leakage in the sealing parts of the reducer and lubrication station.

According to the application characteristics of the mine hoist, the speed ratio requirements of the single-rope winding mine hoist to the reducer: 10-35; the general requirements of the speed ratio of the multi-rope friction type mine hoist reducer: 7-15; the transmission torque of the reducer Range: 30 kNm~1800 kNm; gear transmission power can meet more than 5000 kW.

two

Main types and technical characteristics

There are four main categories of hoist reducers:

1. Single input shaft parallel shaft gear reducer;

2. Double input shaft parallel shaft gear reducer;

3. Coaxial power split gear reducer;

4. Planetary gear reducer.

1 Single rope winding type hoist reducer

The types of reducers for single-rope winding hoists mainly include ZL, ZHLR, PTH, ZZ and ZK types, with a transmission ratio of 11.2-31.5 and two-stage transmission.

The ZL and ZHLR types are involute and arc-shaped herringbone parallel shaft reducers respectively; the PTH type is a medium-hard involute helical gear reducer.

According to the requirements of the hoist on the transmission ratio of the reducer, ZK series mainly use ZKL (two-stage transmission) and ZKP (single-stage derivative transmission), and ZZ series mainly use ZZL (two-stage transmission), ZZDP (single-stage derivative transmission) and ZZLP (two-stage derivative transmission) type.

With the development of hard-tooth surface gear technology and planetary gear reducer technology, ZK (JB/T 12808-2016) and ZZ (JB/T 9043-2016) series planetary gear reducers are mainly used for hoists at present.

2 Multi-rope friction hoist reducer

The common supporting reducers of multi-rope friction hoists mainly include spring base reducer, double input parallel shaft reducer and planetary gear reducer. The transmission ratio of the multi-rope friction hoist reducer is i=7.1-11.2.

The spring-based reducer is a coaxial transmission, which mainly solves the impact of the hoist starting and braking on the well tower; for the hoist system with a power greater than 1000kW, it is suitable for double motor drive; the planetary transmission adopts a single-stage derivative, and the ZK series is equipped with ZKP Type, ZZ series with ZZDP type.

3 Comparison of planetary reducer and parallel shaft reducer

Transmission ratio: i=7.15, power: P=4412 (kW)

1) Power split; 2) Reasonable application of internal meshing; 3) Large transmission ratio; 4) High transmission efficiency; 5) Smooth movement, strong shock and vibration resistance.

three

Reducer research and development process and key quality control technology

1 Product development process of reducer

2 Standards-based gear product design

The Gear Equipment Research Institute can design and manufacture gear products according to customer requirements and adopt domestic and foreign standards. Mainly used standards: ISO, AGMA, DIN, etc.

3 Bearing selection and life calculation

Use ISO281 and ISO TS16281 to calculate the life of each bearing taking into account the fitting tolerance of the box and shaft, thermal elastic deformation under load, lubricating oil viscosity, pollution particles, temperature rise and fatigue life.

The main factors considered in the selection of gearbox bearings in the building materials industry: 1) Bearing tolerance - effective clearance; 2) Thermal elastic deformation of the transmission system; 3) The impact of bearing support stiffness on gear contact.

4-axis parts design

Technical points:

1) Structural static strength analysis of shaft (stress and strain);

2) Determination of fit tolerance of multi-body coupling based on thermal elastic deformation (box, bearing, gear, thermal deformation, deformation under load, etc.);

3) Structural optimization of shaft components considering tooth surface contact (elastic deformation consistency control technology);

4) Shafting dynamic characteristic analysis and performance evaluation (determination of critical speed to avoid resonance).

5. Lightweight design of cabinet based on finite element

The function of the box:

1) Avoid the influence of the external environment on the transmission system;

2) Ensure the strict positional relationship of key components of the transmission system;

3) Component integration.

Box design points:

1) Structural mechanics analysis (stress, strain);

2) Structural dynamics analysis (modal analysis, dynamic response analysis);

3) Human-computer interaction.

6 Gear modification technology based on system elastic deformation

7 Lubrication system design technology

8 Kinetic analysis and performance evaluation

Considering the time-varying mesh stiffness, clearance error, damping, bearing stiffness and other factors in gear transmission, a three-dimensional contact nonlinear dynamic analysis model of planetary gear train-bearing-casing is established. The model conducts transient dynamic analysis, realizes the dynamic simulation of the meshing impact of the gear system, and provides the basis for the optimal design of vibration reduction and noise reduction of the multi-stage planetary gear reducer.

In order to ensure the design quality, a series of gear product design, analysis and simulation software are used to build a complete set of gear products through standardized design, static optimization analysis, dynamic analysis and performance evaluation, in-plant test and field practice verification. R&D system.