Safety valve structure of gearbox of backhoe loader

Abstract

The utility model discloses a safety valve structure of a gearbox of a backhoe loader. The safety valve structure comprises a box body, a valve cover, a spring, a valve core, a locking bolt and a spring washer, the box body is provided with an oil drainage hole, a main oil duct and two threaded holes, and the main oil duct is located between an oil outlet of the variable-speed oil pump and an oil inlet of the pressure regulating valve; the valve cover is provided with a valve core hole; one end of the valve core is embedded into the oil drainage hole, and the other end is sleeved on the valve core hole of the valve cover; the spring is sleeved on the valve core and is positioned in the valve cover; and the valve cover is fastened on the box body by two locking bolts and a spring washer through two threaded holes. The pressure regulating valve is simple and compact in structure, convenient and efficient to assemble and long in service life, and solves the problem that other parts are damaged due to clamping stagnation of the pressure regulating valve core caused by substandard cleanliness of hydraulic transmission oil in the prior art.

Description

Technical Field

[0001] The utility model relates to the technical field of a gearbox assembly of an excavator loader, in particular to a gearbox safety valve structure of an excavator loader. Background Art

[0002] As agriculture at home and abroad develops towards mechanization, backhoe loaders are favored by customers for their mobility and flexibility, as well as their multifunctional advantages of being able to perform both shoveling and loading operations. Their market demand is also steadily increasing. Backhoe loader gearboxes generally use electro-hydraulic control shifting, which is more complex and precise than conventional loader gearboxes. Therefore, they have high requirements for the cleanliness of hydraulic transmission oil. When the cleanliness of hydraulic transmission oil does not meet the standard, it is easy to cause the pressure regulating valve core to become stuck, causing the system pressure to increase, and causing the fine filter bypass valve to open. After the fine filter bypass valve is opened, the fine filter cannot play an effective filtering function. The oil that does not meet the cleanliness standard will further damage the control valve, and even cause the fine filter to burst. Summary of the invention

[0003] The utility model aims to solve the above defects and provide a gearbox safety valve structure for an excavator loader with a simple and compact structure, convenient and efficient assembly and a long service life, so as to solve the problem in the prior art that the pressure regulating valve core is stuck and other parts are damaged due to the unqualified cleanliness of the hydraulic transmission oil.

[0004] To achieve the above purpose, the utility model provides a gearbox safety valve structure for an excavator loader, comprising a housing 1, a valve cover 2, a spring 3, a valve core 4, a locking bolt 5 and a spring washer 6; the housing 1 is provided with an oil drain hole 1.2, a main oil passage 1.3 and two threaded holes 1.1, the main oil passage 1.3 is located between the oil outlet of the transmission oil pump and the oil inlet of the pressure regulating valve; the valve cover 2 is provided with a valve core hole; one end of the valve core 4 is embedded in the oil drain hole 1.2, and the other end is sleeved on the valve core hole of the valve cover 2; the spring 3 is sleeved on the valve core 4 and is located in the valve cover 2; the valve cover 2 is fastened to the housing 1 by two locking bolts 5 and a spring washer 6 through two threaded holes 1.1.

[0005] The utility model discloses a gearbox safety valve structure for a backhoe loader, which has the following technical features and beneficial effects by adding a safety valve to the main oil passage between the oil outlet of the speed change oil pump and the oil inlet of the pressure regulating valve:

[0006] 1. Adding a safety valve to the main oil passage between the oil outlet of the speed change oil pump and the oil inlet of the pressure regulating valve can effectively avoid the problem of increased system pressure due to the jamming of the pressure regulating valve core, thereby avoiding damage to other parts and solving the problem in the prior art that the pressure regulating valve core is jammed and other parts are damaged due to the substandard cleanliness of the hydraulic transmission oil;

[0007] 2. The structure is simple and compact, the assembly is convenient and efficient, and the use is safe and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 The utility model is a schematic diagram of the structure of a gearbox safety valve of an excavator loader.

[0009] Figure 2 yes Figure 1 Schematic diagram of the cross-sectional structure along the AA axis.

[0010] Reference numerals: housing 1, threaded hole 1.1, oil drain hole 1.2, main oil channel 1.3, valve cover 2, spring 3, valve core 4, locking bolt 5, spring washer 6. DETAILED DESCRIPTION

[0011] The specific implementation of the gearbox safety valve structure of an excavator loader of the utility model is further described in detail below in conjunction with the accompanying drawings.

[0012] Figure 1-Figure 2 As shown, the utility model is a backhoe loader gearbox safety valve structure comprising a housing 1, a valve cover 2, a spring 3, a valve core 4, a locking bolt 5 and a spring washer 6; the housing 1 is provided with an oil drain hole 1.2, a main oil passage 1.3 and two threaded holes 1.1, the main oil passage 1.3 is located between the oil outlet of the transmission oil pump and the oil inlet of the pressure regulating valve; the valve cover 2 is provided with a valve core hole; one end of the valve core 4 is embedded in the oil drain hole 1.2, and the other end is sleeved on the valve core hole of the valve cover 2; the spring 3 is sleeved on the valve core 4 and is located in the valve cover 2; the valve cover 2 is fastened to the housing 1 by two locking bolts 5 and a spring washer 6 through two threaded holes 1.1.

[0013] When assembling the valve core 4, the spring 3 is first installed, and after the valve cover 2 is buckled, the valve cover 2 is fastened to the box body 1 using two locking bolts 5 and spring washers 6.

[0014] When the pressure regulating valve core of the gearbox is stuck during operation, the pressure regulating valve cannot adjust the system pressure and the system pressure will increase; when the system pressure is greater than the set value of the safety valve, the valve core 4 will push the compression spring 3 and open the valve core 4, and the transmission oil will flow into the box through the oil drain hole 1.2, reducing the pressure of the main oil channel system, thereby avoiding the problem of damage to other components caused by the opening of the fine filter bypass valve.

Claims

1. A gearbox safety valve structure for an excavator loader, characterized by: It comprises a housing (1), a valve cover (2), a spring (3), a valve core (4), a locking bolt (5) and a spring washer (6); the housing (1) is provided with an oil drain hole (1.2), a main oil passage (1.3) and two threaded holes (1.1); the main oil passage (1.3) is located between the oil outlet of the variable speed oil pump and the oil inlet of the pressure regulating valve; the valve cover (2) is provided with a valve core hole; one end of the valve core (4) is embedded in the oil drain hole (1.2), and the other end is sleeved on the valve core hole of the valve cover (2); the spring (3) is sleeved on the valve core (4) and is located in the valve cover (2); the valve cover (2) is fastened to the housing (1) by two locking bolts (5) and a spring washer (6) through the two threaded holes (1.1).

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