Function of bogie center pin

The function of the bogie center pin is to increase the load of the vehicle. As an independent running device, the bogie needs to bear the weight and external force of the vehicle and guide the vehicle to run on the line. The following is about the role sharing of the bogie center pin.

Function of bogie 1 center pin I. Function of bogie

1, as an independent running mechanism, the bogie has the functions of supporting the car body, bearing the weight and external force of the vehicle and guiding.

Vehicles are running on the line.

2. Through the cooperation and relative rotation between the car body and the bogie, the vehicle can smoothly pass through the curve, greatly reducing the running resistance.

3. It can improve the running stability of vehicles.

4. Three-axle and multi-axle vehicles can be used to adapt to and improve the carrying capacity of vehicles.

Second, the composition of the bogie

1. Wheelset axle box device-Wheelset rolls along the rail and transmits various forces between the wheel and rail, including vehicle weight, traction and braking force. Axle box or bearing device converts the rolling of wheelsets into the translation of the car body along the track.

2. Elastic suspension device-in order to reduce various dynamic influences (such as vertical vibration and lateral vibration, etc.). ) caused by track irregularity and wheelset movement on the car body; It is divided into primary suspension (axle box suspension device) and secondary suspension (bolster central suspension device). Comprise a spring device, a damping device, a positioning device and that like.

3. Frame or side frame-The frame or side frame is the foundation of the bogie, which integrates all parts of the bogie into a whole, not only

To bear and transmit all kinds of forces and loads, its structure, shape and size should meet the structure, shape and assembly requirements of all parts.

4. Basic braking device-transmits and amplifies the braking force of the brake cylinder, that is, converts the internal friction between the brake shoe and the wheel into the external friction (braking force) between the wheel and the rail, so that the vehicle can bear the resistance in the forward direction and produce braking effect, so that the driving vehicle can stop within a specified distance.

5. The device for the bogie to support the car body-support the car body safely and reliably, and bear and transmit various forces (such as vertical force and vibration force); In order to make the vehicle pass the curve smoothly, the car body and bogie can rotate relatively around a constant rotation center. Three. Classification of bogies

The main differences of various bogies are: the number and type of bogies, the structure and parameters of spring suspension system, the transmission mode of vertical load, the support mode of wheelsets, the positioning mode of axle boxes, the type and installation of braking devices, and the structure of frames and side frames.

(a), according to the shaft number, type, shaft box positioning method classification.

1, classified by shaft number and type.

According to the number of axles, bogies have two axles, three axles and multiple axles.

2, according to the axle box positioning way classification

The mechanism to limit the relative movement between wheelset and frame is called axle box positioning device.

Proper axle box positioning stiffness can not only avoid the loss of stability of the vehicle in the running speed range, but also ensure that the vehicle has good steering performance on the curve, thus reducing the lateral force between the wheelset and the rail, reducing the wear of the wheel rim and the rail, and ensuring the safety and stability of the vehicle.

(1), fixed positioning

(2) Positioning of guide frame-there is a guide groove on the axle box or a guide frame on the side frame, and the guide frame is inserted into the guide groove. This structure allows a relatively large relative displacement in the vertical direction, but the displacement is relatively small only within the allowable gap range in the vertical and horizontal directions. (3), dry friction guide column positioning

(4), guide cylinder positioning

(5), pull plate positioning

(6), pull rod positioning

(7), rotating arm positioning

(8), rubber spring positioning

(2), according to the spring suspension device classification

1, primary spring suspension-On vehicles with primary suspension, there is only one primary spring damping device from the car body to the wheelset, some between the car body (bolster) and the frame (side frame), and some between the frame and the wheelset axle box. With a series of suspensions, the bogie is relatively simple in structure, convenient in maintenance and low in manufacturing cost, so it is generally used on freight car bogies.

2. Secondary spring suspension-On vehicles equipped with secondary suspension,

From the car body to the wheelset, there are secondary spring damping devices, and there are both bolster spring damping devices and axle box spring damping devices on the bogie.

According to the different transverse spans of springs in bolster suspension, the suspension forms are divided into:

1, internal suspension

2. External suspension

3. Central suspension

(three) according to the vertical load transfer mode classification:

1, center bearing of center plate

2. Bearing without center plate

3. Bearing of center plate part

Review question: What is the general composition and function of bogies?

The role of the center pin of bogie 2 in the second quarter turns to 8A bogie.

I. Structure

It consists of a side frame, a bolster spring damping device, a wheelset axle box lubricating device and a foundation braking device.

(1) side frame

It is an important basic component of the bogie, located on both sides of the bogie, and is used to connect the bolster and the bearing seat and transmit force.

Names of all parts of the side frame: upper chord beam, upper oblique chord beam, axle box bearing platform, inspection hole, oblique wedge, upright post, side frame guide frame, brake beam chute, protruding navel, bolster hole, lower oblique chord beam, etc.

Bolster hole-used to install bolster, bolster spring and shock absorber.

Column-The opposite planes of columns on both sides of the frame are friction surfaces, which are 2 degrees and 30 minutes from the vertical, and wear-resistant plates are welded on them.

Inclined wedge block-mainly to prevent the side frame from being separated from the bogie when it is laterally stable during the bolster spring period, and as a safety block to ensure that the bolster is connected together.

The guide frame of the side frame-the guide frame and the guide groove of the bearing seat define the front, rear, left and right gaps between the wheelset and the side frame.

Inspection hole-convenient for overhaul of foundation braking device and replacement of brake shoes.

(2) Bearing beam spring shock absorber

It consists of bolster, lower center plate, lower side bearing, bolster spring and wedge friction damper.

1, bolster

Function: on the one hand, the force acting on the lower center plate of the car body is transmitted to the springs supporting it at both ends; On the other hand, it connects the left and right side frames of the bogie into a whole. Shape: fish-bellied, hollow, suitable for the characteristics of large bending moment in the middle and small bending moments at both ends. Wedge groove: Install shock absorber.

2. Lower center plate

Function: bear the horizontal and vertical forces on the car body; In addition, when the vehicle passes through the curve, the bogie can freely rotate around the center plate to reduce the resistance through the curve.

Center plate pin: prevent the upper and lower center plates from falling off.

Adjust the coupler height: add a pad with appropriate thickness between the lower center plate and the bolster to adjust the coupler height.

3. Lower bearing

During normal operation, the clearance between the upper and lower bearings: the sum of the clearance between the left and right sides is 10- 16 mm, and the minimum clearance on each side is not less than 4MM, and it is allowed to be 2-20 mm during operation. If the clearance is too large, the vibration and inclination of the car body will increase, but if it is too small, the side bearing will contact prematurely and the resistance will increase, which is not conducive to the bogie passing through the curve.

4. Bearing beam spring

There are 7 groups of double spiral springs in the rotor 8A, of which 5 groups are supported under the bolster and 2 groups are supported under two inclined wedges.

Function: Relieve and reduce the vibration and impact of vehicles.

5. Inclined wedge friction damper

Function: Lighten and reduce the vibration of the vehicle and keep the positioning function of the two side frames.

Composition: inclined wedge, damping spring, side frame column wear plate and bolster.

Inclined wedge-triangle, with vertical plane as the main friction surface and 2030 "'from vertical line, and inclined plane as the secondary friction surface, horizontal.

The included angle of these lines is 450 degrees. The umbilical hole protruding from the bottom of the wedge constitutes the spring position. Generally cast steel or steel plate surface.

(3) Lubrication device for wheelset axle box

Roller 8A adopts RD2 wheelset, 197726 bearing, and is positioned in the way of guide frame through bearing seat and side frame. (Some use rubber.

The axle load of this type of bogie is 2 1 ton, so the total weight of freight cars using this type of bogie does not exceed 84 tons.

(4) Foundation braking device

Chute-type arch brake beam is adopted, and one-side brake shoe is used for braking. It is mainly composed of brake beam, movable lever, fixed lever, lower pull rod, brake shoe, brake shoe holder, roller shaft, cotter pin, brake shoe pin, roller sleeve, safety crane, etc.

Second, the vertical force transfer order bolster spring

Body center plate

Lower center plate rocker wedge, damping spring and spring supporting platform

Wear-resistant plate of side frame column

Side frame bearing saddle bearing journal wheel

Railway.

Three. Main advantages and disadvantages of Zhu8a bogie

Advantages: 1, high strength and large bearing capacity;

2, few fasteners, simple structure, less applause and convenient maintenance;

Review questions:

1. Composition of freight car bogies.

2. Composition of bogie for Zhu8a.

In the fourth quarter, the center pin of bogie turns 3 k 1 k2, and the function of bogie.

First, the defects of the bogie of Zhuan 8A

(1) diamond has low rigidity.

⑵ The static deflection of empty car is small, and the dynamic performance of empty car is poor.

⑶ The vibration damping performance is unstable.

(4) Poor wear resistance.

In this way, the running speed of freight trains is limited to 70km/h, and the system is controlled.

The speed of freight trains further affects the speed of passenger trains.

Development.

Second, turn to k2 bogie

1, structural characteristics

Turning k2 bogie belongs to three bogies with variable friction devices. An elastic lower cross supporting mechanism is installed between the two side frames, the cross bar passes under the bolster, and four end points are connected with the side frames through axial rubber pads; The side frame and bolster are made of grade B steel; The rocker device adopts a separated inclined wedge, and a wedge-shaped insert plate is welded on the rocker (the other is that the rocker device adopts an integral inclined wedge, and a flat wear plate is welded on the rocker);

The foundation braking device is an intermediate pull rod structure; The central suspension system adopts two-stage stiffness spring; A middle disc wear-resistant disc is arranged between the upper middle disc and the lower middle disc; Adopt double-acting elastic side bearing; The wear plates of embedded chute and side frame column are made of T 10 steel. P65, P65s and P65A luggage express boxcars with speed of Kloc-0/20km/h are equipped with high-friction synthetic brake shoes ... High-phosphorus brake shoes are installed on speed-increasing vehicles with speed of Kloc-0/00km/h, such as C64B, P64AK, C64AK, etc.

2. Main equipment

Elastic cross support device of (1) side frame

Composition: lower cross bar (1) and upper cross bar (1),

Axial rubber pads (8 pieces) and ear washers (4 pieces)

Locking plates (4 pcs) and fastening nuts (4 pcs)

A splint is welded between the upper and lower cross bars. The splint is fastened by two sets of M 12 bolts, and the nut is fixed by electric welding. There are four plug welds and two flat welds between the clamping plates, which connect the upper and lower cross bars into a whole.

(2) the composition of the side frame

The side frame is mainly composed of a side frame, a supporting seat, a retaining ring and a column wear plate.

Chute wear plate and other parts.

(3) Supporting composition

The bolster is mainly composed of a fixed lever fulcrum seat, a bracket, a bolster,

Lower center plate, inclined wear plate, etc.

(4) Central suspension system

The central suspension system consists of 10 outer ring spring, 10 inner ring spring and four groups of double coil damping springs.

Two-stage stiffness spring formation;

The free height of the outer ring spring is 22mm higher than that of the inner ring spring, and it is only outside when it is empty.

The spiral spring bears the load, and the inner and outer spiral springs bear the load at the same time when the car is heavy, thus realizing empty weight.

Two-stage rigidity of vehicle. The damping spring is higher than the bolster spring. The spring material is:

60Si2 CrVA

5] Damping device

(1) Separate shock absorber

It consists of side frame column wear plates and left wedge (or right wedge).

Wedge insert plate (made of 20 steel) and double-ring damping spring.

② Integral vibration damping device

The integral left inclined wedge vibration reduction device consists of a side frame column wear plate, an inclined wedge and a bolster.

Inclined wear plate (0Cr 18Ni9) and double-ring damping spring.

[6] Double-acting elastic side bearing

The double-acting elastic side bearing consists of an elastic side bearing (rubber composite spring), a side bearing seat,

Roller, adjusting pad and adjusting washer.

Once the basic braking device

The foundation braking device consists of left and right channel steel arch braking beams and intermediate pull rods.

Composition (divided into 1 and 2 bits): fixed lever, fixed lever fulcrum and swimming.

Lever, high friction synthetic brake shoe (or high phosphorus brake shoe) and wear-resistant pin sleeve.

New technology: welding a special brake shoe trailer with anti-falling plate at the end of brake beam. bottom

The sleeve adopts austenite-bainite ductile iron wear-resistant bushing, and the round pin is No.45 round pin.