RU2806384C1 - Road grader balancing trolley - Google Patents

Abstract

FIELD: road graders.

SUBSTANCE: balancing trolley of a road grader includes a central gearbox, a main gear with a differential, axle shafts, disc brakes and planetary gears located in it, longitudinal symmetrical balancers located at the ends of the central gearbox and freely rotating on an axis common with its axle shafts, a balancer power transmission transmitting rotation from the central gearbox onto the wheels located at the ends of the balancers without changing direction. The gear ratio of the balancer power transmission from the central gearbox to each of the wheels is equal to: R/H, where R is the radius of the wheel; H is the height of the balancer turning point. Disc brakes are located in the central gearbox between the main gear and the planetary gear. The moving elements of the disc brakes are fixed on the axle shafts, and the fixed ones are connected to the central gear housing.

EFFECT: increase in the adhesion properties of the road grader during traction and braking and an increase in the service life of both individual components and the trolley as a whole.

1 cl, 3 dwg

Description

The invention relates to earth-moving and transport machines, mainly motor graders.

The balancing trolley of the A120 motor grader is known (https://lib.madi.ru/fel/fel1/fel14E193.pdf) consisting of a central gearbox containing a main gear with a differential and planetary final drives, and two longitudinal symmetrical balancers rotating on a common planetary axle transmission. Balancers have a gear transmission from the central gearbox to the wheels without changing the direction of rotation with a gear ratio of one. The axis of rotation of the balancer is made visually higher than the plane containing the axes of rotation of the wheels of the balancer. The service brakes are drum brakes, located on the wheel hubs.

The balancing trolley of the motor grader DZ-180 is known (http://usts-ekb.ru/file/pdf_files/4/katalog_DZ-180.pdf), according to the description it matches the trolley of the A120 motor grader, but unlike it, for the balancer the wheel axes and the turning axis lie in the same plane. This trolley is the closest analogue to the stated technical solution of a balancing trolley (prototype) in terms of the largest number of essential features identical to it.

The balancing trolley of the motor grader DZ-122 with balancers DZ-122.04.06.000 (http://www.avtoall.ru; http://www.sonarr.ru) is also known, according to the description they match the balancers of the motor grader A120 with the difference that they have a gear the number from the central gearbox to the wheels is 1.5.

Also known are the designs of balancing carts for forestry machines with a gear drive inside a symmetrical balancer and with wheel gearboxes rigidly mounted on the balancer body, which have less weight, smaller dimensions and greater ground clearance (RU 2019444 C1, publ. 09/15/1994) with a gear ratio from the output axle shaft of the central gearbox to wheels of several units without changing the direction of rotation.

Balancing trolleys with planetary wheel gears rigidly attached to the balancer body are also used on graders (RU 24210 U1, published July 27, 2002), where symmetrical balancers with a chain drive and a visually noticeable elevation of the axis of rotation of the balancer above the plane containing the axes of rotation of the wheels are used. The gear ratio from the central gearbox shaft to the wheels will also be several units. The service brakes are disc brakes in an oil bath, located on the wheel hubs.

Structural elements close to the stated technical solution of the balancing trolley are also contained in SU 519525, publ. 06/30/1976; RU 19514 U1, publ. 09/10/2001; RU 101675 U1, publ. 01/27/2011.

The advantage of the prototype, in contrast to the other given designs, is to ensure uniform distribution of vertical reactions in traction mode. Authors SU 1763249 A1, publ. 09.23.1992; SU 1763250 A1, publ. 09.23.1992; RU 2189911 C2 publ. 09.27.2002 they criticize designs similar to the prototype and propose options for reducing the weight and dimensions of the balancing carts while maintaining the uniformity of vertical reactions in traction mode, but introduce additional reaction rods, and in RU 2707676 C1, publ. 11.28.2019 and RU 2716395 C1 publ. 03/11/2020 - electronic control, significantly complicating the design. The use of an asymmetrical balancer (RU 2749429 C1, published 06/10/2021; RU 2563468 C1, published 09/20/2015) ensures uniformity only at a fixed value of the traction force.

Among the shortcomings of the prototype, one can note a design limitation on the amount of ground clearance under the central gearbox, imposed by the condition of the location of the axis of rotation of the balancer and the axes of rotation of the wheels in the same plane. The disadvantage of the prototype, as well as the considered designs of balancing carts for motor graders A120, DZ-122 and RU 24210 U1, is the high unevenness of vertical reactions during braking. The rest of the sources cited here do not consider the braking process at all.

Since the adhesion mass has a positive effect on traction properties, and the unevenness of vertical reactions has a negative effect, a simpler design, like that of the prototype, is preferable for a motor grader, if it is necessary to ensure conditions for the uniformity of vertical reactions for both traction and braking modes.

The objective of the invention is to create a balancing trolley with a symmetrical balancing beam for a motor grader, ensuring uniform distribution of wheel loads during traction and braking, and to determine the conditions for ensuring this uniformity.

The technical result of the invention is to increase the adhesion properties of the motor grader during traction and braking and increase the service life of both individual components and the trolley as a whole.

To achieve the objective of the invention, the author considered the forces acting on the balancer of a motor grader moving at speed V in traction mode (Fig. 1), such as: torques from wheels T ₂ and T ₃ , traction forces from wheels F ₂ and F ₃ , vertical reactions from wheels R ₂ and R ₃ , forces from the central gearbox - vertical P ₂₃ , horizontal F ₂₃ , and torque from the output axle T _n . _. The braking mode will differ in the action of torques T ₂ , T ₃ , T _n and traction forces F ₂ , F ₃ , F ₂₃ in the other direction. As a result of solving the compiled equilibrium equations, taking into account the condition of uniformity of vertical reactions for both traction and braking modes, the dependence of the gear ratio i=Z ₂ /Z ₁ inside the symmetrical balancer on the wheel radius R and the height of the turning point of the balancer H was ultimately obtained.

In the proposed design, the results of the solution are reflected by placing service brakes in the central gearbox on both sides on the axle shafts between the main gear with differential and planetary gears (Fig. 2).

In fig. 1 shows a diagram of the acting loads on the symmetrical balancer of the balancing trolley of a motor grader in traction/braking mode;

In fig. 2 shows a kinematic diagram of the balancer of the balancing trolley of a motor grader;

In fig. Figure 3 shows a kinematic diagram of the balancing trolley of a motor grader.

The declared balancing trolley of a motor grader (Fig. 2, 3) contains a central gearbox 2, rigidly connected to the sub-engine frame, and symmetrical balancers 1 freely rotating around its axis 0. The central gearbox houses the main gear with a differential 3, axle shafts 6, disc brakes 7 and planetary gears 4. Disc brakes are located in an oil bath between the main gear and the planetary gear. The moving disks are secured against rotation on the axle shaft, and the fixed ones are secured to the housing of the central gearbox. The sun gear of the planetary gear is connected to the axle shaft, and the epicyclic gear is connected to the housing of the central gearbox. The power transmission of the balancer from the central gearbox to each of the wheels consists of an odd number of gears, which causes the rotation of gear Z ₁ associated with the planetary gear carrier, and gear Z ₂ associated with wheel 8, in one direction, which is one of the conditions for the balance of the balancer carts. Another condition is the equality or close to it of the balancer gear ratio i=Z ₂ /Z ₁ and the R/H value, where the units of measurement for the R and H values are the same.

The operation of the trolley in traction mode is as follows. The input torque applied to flange 5 acts on the main gear and is distributed through the differential over two axle shafts, which transmit rotation through the sun gears of the planetary gears to the carrier and then to the balancer gears Z ₁ . Inside the balancers, from gear Z ₁ , torque is transmitted through idler gears to wheel gears Z ₂ and then through the shafts connected to them to the wheels.

When braking, axial forces are applied to the brake disc blocks. As a result, the movable and stationary brake discs close together and a frictional force arises between the discs. Braking torques, perceived by the central gearbox housing, are transmitted to the axle shafts, then through the planetary gearbox to the carrier, gears Z ₁ , idler gears of the balancer, gears Z ₂ , shafts connected to them and reach the wheels. The braking energy is transmitted through the oil to the central gear housing mainly in the area where the disc brakes are located.

Claims (4)

The balancing trolley of a motor grader, including a central gearbox, a main gear with a differential, axle shafts, disc brakes and planetary gears located in it, longitudinal symmetrical balancers located at the ends of the central gearbox and freely rotating on an axis common with its axle shafts, a balancer power transmission transmitting rotation from the central gearbox to the wheels located at the ends of the balancers without changing direction, characterized in that the gear ratio of the balancer power transmission from the central gearbox to each of the wheels is equal to: R/H, where R is the radius of the wheel; H - height of the turning point of the balancer; in this case, the disc brakes are located in the central gearbox between the main gear and the planetary gear, the moving elements of the disc brakes are fixed on the axle shafts, and the fixed ones are connected to the housing of the central gearbox.

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