RU2187601C2 - Excavator slewing mechanism - Google Patents

Abstract

FIELD: earth moving equipment; excavators. SUBSTANCE: proposed mechanism has hydraulic motor whose shaft is connected with gear-shaft of reduction gear means of flexible coupling consisting of driven and driving coupling members, and disk type brake. Slewing mechanism is furnished additionally with hydraulic damper including housing with radial partitions and shaft with blades arranged on driven coupling member of flexible coupling with clearance between blades and inner surface of housing. Valve of clearance is found from following equation

, where b is width of blade; μ_e= ν_e•ρ - is dynamic viscosity of liquid; ν_e - is kinematic viscosity of liquid; ρ - is density of working liquid; Z is number of blades; l is length of slot; D and d are inner diameter of housing and diameter of shaft, respectively; ω_d - is shaft angular velocity; M_d is damper brake torque. EFFECT: increased reliability of excavator slewing mechanism. 2 dwg

Description

 The invention relates to earthmoving machines, namely to excavators.

 The known mechanism of rotation of the platform (AS USSR 1678990 A1, IPC E 02 F 9/12, 1991), which includes an engine, gear housing with holes for mounting parts to the platform and an annular protrusion arranged concentrically to the output shaft to interface with the mounting hole platforms, output gear meshing with the ring gear.

 The disadvantage of this device is the presence of a high peak load at the time of starting and braking the rotation of the turntable.

 The known rotation mechanism (universal single-bucket excavator EO-4121A. Technical description. Operating instructions. - Kovrov, 1978 - page 61, Fig. 19, 59), which includes a hydraulic motor, an elastic coupling consisting of half couplings and rubber checkers, three-stage gearbox and brake.

 The disadvantage of this device is the frequent kink of the gear teeth occurring under the influence of the peak load at the time of acceleration / deceleration of the turntable.

 The objective of the invention is to increase the reliability of the mechanism of rotation of the excavator by reducing the peak load at the time of acceleration / deceleration of the platform.

где b - ширина лопасти;
μ_ж= ν_ж•ρ - динамическая вязкость жидкости;
ν_ж- кинематическая вязкость жидкости;
ρ - плотность рабочей жидкости;
Z - количество лопастей;
l - длина щели;
D и d - внутренний диаметр корпуса и диаметр вала;
ω_дпф- угловая скорость вала;
М_дпф - тормозной момент демпфера.This problem is solved in that the excavator turning mechanism comprising a hydraulic motor, the shaft of which is connected to the reduction gear shaft by means of an elastic coupling consisting of a driven and leading coupling half, and a disk type brake, according to the invention, is additionally equipped with a hydraulic damper comprising a housing with radial partitions and a shaft with blades located on the driven coupling half of the elastic coupling with a gap between the blades and the inner surface of the housing, the gap is determined by the following ratio:

where b is the width of the blade;
μ _W = ν _W • ρ - dynamic viscosity of the liquid;
ν _W - kinematic viscosity of the liquid;
ρ is the density of the working fluid;
Z is the number of blades;
l is the length of the slit;
D and d are the inner diameter of the housing and the diameter of the shaft;
ω _dpf is the angular velocity of the shaft;
M _dpf - braking torque of the damper.

 The proposed damper in the mechanism of rotation of the excavator can reduce peak load, increases the service life of the gearbox of the rotation mechanism, improves the ergonomic working conditions of the driver.

 Figure 1 shows the brake of the rotation mechanism with a hydraulic damper in the context; figure 2 is a section aa in figure 1.

где b - ширина лопасти;
μ_ж= ν_ж•ρ - динамическая вязкость жидкости;
ν_ж- кинематическая вязкость жидкости;
ρ - плотность рабочей жидкости;
Z - количество лопастей;
l - длина щели;
D и d - внутренний диаметр корпуса и диаметр вала;
ω_дпф- угловая скорость вала;
М_дпф - тормозной момент демпфера.The rotation mechanism consists of an axial piston hydraulic motor 1, the shaft 2 of which is connected to the gear shaft 3 of the gearbox by an elastic coupling, consisting of two half-couplings - a drive 4 and a driven 5, made with slots 6, and rubber blocks 7. Brake of the disk-type rotation mechanism - normally closed, consisting of a driven disk 8 with friction linings 9, a pressure disk 10, pressed against the driven disk 8 by springs 11, is located between the elastic coupling and the housing 12 of the gearbox. The excavator turning mechanism is equipped with a hydraulic damper, consisting of a housing, which is a driven disk 8 of the rotation mechanism brake, with two radial partitions 13 and a shaft 14 with two blades 15 mounted on the splines 6 of the driven half coupling 5. The blades 15 of the shaft 14 are installed with a gap δ relative to the inner surface of the housing in the form of a driven disk 8, through which the liquid is throttled when turning on or off the rotation mechanism to a limited angle. The size of the gap is determined from the following ratio:

where b is the width of the blade;
μ _W = ν _W • ρ - dynamic viscosity of the liquid;
ν _W - kinematic viscosity of the liquid;
ρ is the density of the working fluid;
Z is the number of blades;
l is the length of the slit;
D and d are the inner diameter of the housing and the diameter of the shaft;
ω _DPF is the angular velocity of the shaft;
M _dpf - braking torque of the damper.

 To connect the damper to the work, it is necessary that when the rotation mechanism is turned off, the delay of disconnection and application of the brake is delayed. This is ensured by the passage of fluid to the brake hydraulic cylinders 16 through an uncontrolled throttle.

 The device operates as follows.

 When you turn on and accelerate the rotation mechanism at the first stage, the inertial forces of the rotary part of the excavator do not allow the gear shaft 3 of the gearbox to rotate, as a result of which the shaft 2 of the hydraulic motor 1 through the coupling will turn the damper shaft 14 by a certain angle and reduce the dynamic moment by throttling the fluid from one cavity damper to another through the gap δ between the blades 15 and the housing in the form of a driven disk 8. When turning off the hydraulic motor 1 and slowing down the rotation speed of its shaft 2, the clutch and the damper shaft 14 under the action of inertia x forces rotary part of the excavator of the damper housing will rotate with friction linings 9 and reverse movement of the shaft 14 of the damper and the damping portion of braking energy. When this occurs, the brake is delayed due to the throttle in the hydraulic line of the cylinders 16 and the return of the damper blades 15 to their original position. The degree of delay is determined by adjusting the area of the throttle hole in the hydraulic actuator.

Claims (1)

An excavator turning mechanism, comprising a hydraulic motor, the shaft of which is connected to the gear shaft by means of an elastic coupling consisting of a driven and driving coupling half, and a disk-type brake, characterized in that the turning mechanism is further provided with a hydraulic damper comprising a housing with radial partitions and a shaft with blades placed on the driven coupling half of the elastic coupling with a gap between the blades and the inner surface of the housing, the gap value is determined by the following ratio:

where b is the width of the blade;
μ _W = ν _W • ρ - dynamic viscosity of the liquid;
ν _W - kinematic viscosity of the liquid;
ρ is the density of the working fluid;
Z is the number of blades;
l is the length of the slit;
D and d are the inner diameter of the housing and the diameter of the shaft;
ω _dpf is the angular velocity of the shaft;
M _dpf - braking torque of the damper.

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