PIVOT PIN

Abstract

The utility model relates to mechanical engineering, namely to articulated joints of moving elements of equipment, in particular to pins with automatic lubrication supply. The pin comprises a housing (1) with an external spiral groove (4), an axial channel (5) closed at both ends by threaded plugs (2) and (6), wherein the plug (6) has a central opening (7) with a built-in check valve. The following are sequentially arranged in the axial channel: a spring (8), a piston (9), a reservoir (10) for lubricant, an annular shoulder (11) and a temperature-sensitive shut-off unit consisting of a bimetallic washer (12) and a cylindrical sleeve (13) with an annular groove (14) and radial holes (15). The radial opening (3) of the housing is located opposite the sleeve (13). At a temperature below the bending threshold of the washer, the radial opening is blocked by the sleeve; When heated above the threshold, the washer bends, displacing the bushing, aligning the groove with the hole, and the lubricant, under the pressure of the spring (8), enters the spiral groove.A check valve in the plug (6) allows the grease fitting to be disconnected after filling. This prevents overheating, increases the life of the joint, and reduces lubricant consumption compared to continuous supply.

Description

[0001] Technical field

[0002] The utility model relates to the field of mechanical engineering, namely to articulated joints of moving elements of road construction and other equipment, in particular to pins of articulated joints equipped with devices for the automatic supply of lubricant to the friction zone depending on the temperature of the unit.

[0003] Technology Level

[0004] The prior art discloses various designs of articulated joint pins used in mechanical engineering, in particular in road construction equipment.

[0005] The simplest solution is a cylindrical pin (axle) made from a single metal rod. This design does not provide lubrication to the friction zone, leading to intense wear, heating, and seizure of the joint, especially under heavy loads and contamination.

[0006] The first step in the development of these devices was the creation of pins with internal channels for supplying lubricant. Patent SU 1730483 A1 [IPC F16C 11 / 06, published April 30, 1992] describes a hinge joint comprising a pin with an axial and radial channels communicating with it for supplying lubricant, as well as a bushing with seals. This joint is intended for use in lever mechanisms of loaders, excavators, and other machines operating in abrasive environments. A disadvantage of this design is the inability to automatically regulate the lubricant supply depending on the thermal state of the assembly.

[0007] Further developments in the technology are reflected in patent RU 164955 U1 [IPC F16B 21 / 08, published September 27, 2016], which describes a "Quick-Release Coupling Pin" designed as a monolithic axle with a lubrication recess at one end connected to a longitudinal oil channel and a radial opening for discharging the lubricant to the outer surface. A disadvantage of this design is the limited lubricant supply, the inability to refill it during operation, and the lack of flow control.

[0008] The next step in development was pins with a grease nipple (grease press nipple) installed on the end face. These pins feature axial and radial channels for forced grease delivery using a grease gun. This solution makes the pin serviceable, but it still has a drawback: grease is delivered according to a schedule (forced), rather than based on actual demand. At low temperatures, thick grease is ineffectively distributed, and under high loads, grease deficiency can occur.

[0009] The closest approach to the claimed utility model in terms of its features is a swivel pin with automatic grease supply, described in patent CN202673992U [IPC F16C 11 / 04, published January 16, 2013]. This pin comprises a housing with an external spiral groove for distributing grease, an internal axial channel-reservoir containing a spring-loaded piston that constantly applies pressure to the grease, ensuring its continuous supply to the working surface. This design allows for increased service intervals and reduced dependency on human intervention. The disadvantage of this solution is that grease supply is continuous, regardless of the unit's thermal state. When cold, the grease remains thick and is squeezed out of the gap without effective lubrication, which leads to excessive material consumption and environmental pollution.In addition, in low-load mode, excess lubrication is also not required, but with a sharp increase in load and temperature, its supply remains unchanged, which can lead to a lack of lubrication at a critical moment.

[0010] Disclosure of the essence of the utility model.

[0011] Therefore, there is a technical problem - the creation of a hinge pin in which the lubricant is supplied automatically and only when the unit reaches a predetermined threshold temperature, which would ensure lubrication according to actual need, reduce lubricant consumption and increase the service life of the hinge.

[0012] The technical result of the claimed utility model consists in preventing overheating of the hinge pin and its rapid wear, in increasing the service life of the hinge joint, and in reducing the consumption of lubricant in comparison with continuous feed devices.

[0013] The technical result is achieved due to the fact that in the claimed pin of a hinge joint, containing a housing (1) with an outer cylindrical surface on which a spiral groove (4) is made for holding and distributing lubricant, an axial channel (5) is made inside the housing for supplying lubricant, and having a radial opening (3) connecting the axial channel (5) with the spiral groove (4), the axial channel (5) is closed at one end with a threaded plug (2), and on the other side with a threaded plug (6) having a central opening (7) for supplying lubricant with a built-in check valve that ensures one-way passage of lubricant in the direction of the axial channel, while in the axial channel (5) from the plug (2) to the plug (6) a spring (8) is sequentially placed, pressing the piston (9) towards the annular shoulder (11), the piston (9), a reservoir (10) for lubricant, located between the piston (9) and an annular ledge (11), the annular ledge (11) made in the axial channel (5),limiting the stroke of the piston (9) and having a central hole for the passage of lubricant; a heat-sensitive shut-off unit located on the side of the annular shoulder (11) opposite the piston (9) and consisting of sequentially arranged: a bimetallic washer (12) lying on the sleeve (13) and made with the possibility of bending when heated towards the sleeve (13), a cylindrical sleeve (13), on the outer surface of which an annular groove (14) is made, communicating with several radial holes (15) in the wall of the sleeve; wherein the radial hole (3) in the body of the pin is located opposite the cylindrical sleeve (13) in such a way that when the temperature of the pin is below the bending temperature of the bimetallic washer (12), the radial hole (3) is blocked by the sleeve (13),and when the temperature of the pin is higher than the bending temperature of the washer (12), the annular groove (14) is aligned with the radial hole (3) and ensures the passage of lubricant. The housing (1) is equipped with a locking element (17) preventing axial displacement of the pin.

[0014] It is advisable to provide the hinge pin with a fixing element (17) made in the form of an elongated metal plate, fixed at one end to the body (1) on the side of the plug (6) and located perpendicular to the axis of the body (1).

[0015] The temperature-sensitive locking unit in the pin of the articulated joint is designed in such a way that the radial hole (3) in the pin body is located opposite the bushing (13) and is closed in the initial state, whereas when heated to a specified design threshold temperature, the washer (12), bending, shifts the bushing (13) downwards, aligning the annular groove (14) with the radial hole (3) and opens the channel for supplying lubricant to the surface of the pin.

[0016] Thus, with the timely automatic supply of lubricant to the surface of the pin when it reaches a predetermined threshold temperature, i.e. not constantly, but according to actual need, in the claimed utility model, lubricant consumption is reduced, overheating and, as a result, rapid wear of the unit are prevented, and the service life of the hinge joint is also increased.

[0017] Brief description of drawings.

[0018] Fig. 1 shows the external appearance of the pin of the articulated joint for moving elements of machines and mechanisms.

[0019] Fig. 2 shows a longitudinal section of the hinge pin in a cold state (valve closed).

[0020] Fig. 3 shows a longitudinal section of the hinge pin and its heat-sensitive locking unit in three states: a - closed, b - open when heated, c - during servicing.

[0021] Implementation of a utility model.

[0022] Fig. 1, 2 show the external appearance and longitudinal section of the hinge pin assembly (cold state, valve closed).

[0023] The pin comprises a housing (1) formed as an elongated cylinder of metal (e.g., 40X steel). A spiral groove (4) is formed on the outer cylindrical surface of the housing (1) to retain and evenly distribute lubricant. The spiral groove (4) may be located in the middle third of the pin's length, extending one-third of the way from its ends on each side, forming sealing belts.

[0024] An axial channel (5) for supplying lubricant is formed inside the housing (1). The axial channel (5) is closed at one end by a threaded plug (2), and at the other end by a threaded plug (6), which has a central hole (7) for supplying lubricant with a built-in check valve, ensuring one-way passage of lubricant in the direction of the axial channel. A radial hole (3) is formed in the housing (1), connecting the axial channel (5) with a spiral groove (4).

[0025] The following elements are located in the axial channel (5) sequentially from the plug (2) to the plug (6). The spring (8) presses the piston (9) towards the annular shoulder (11), the piston (9) is designed with the possibility of reciprocating movement along the axis, the reservoir (10) for lubricant is located between the piston (9) and the annular shoulder (11). The spring (8) creates constant pressure on the lubricant located in the reservoir (10) through the piston (9).

[0026] The annular shoulder (11) is formed in the axial channel (5), limits the stroke of the piston (9) and has a central hole for the passage of lubricant. The heat-sensitive shut-off unit is located in the axial channel (5) between the annular shoulder (11) and the threaded plug (6) and consists of the following sequentially arranged elements: a bimetallic washer (12), a cylindrical sleeve (13), a return spring (16) (Fig. 2). The bimetallic washer (12) lies on the sleeve (13) and is designed with the possibility of bending when heated towards the sleeve (13), wherein the temperature and the magnitude of the bending are determined structurally - by the choice of material, geometry and preliminary bending of the washer. The washer (12) is made of a thermal bimetallic tape (for example, grade TB 200 / 113 according to GOST 10533-86) and is oriented in such a way that when heated to a structurally specified threshold temperature (for example, 40-50°C), it bends towards the sleeve (13), displacing the sleeve (13) downwards and compressing the return spring (16) (Fig. 3b).The cylindrical bushing (13) is mounted in the axial channel (5) with the possibility of reciprocating movement along the axial channel (5). An annular groove (14) is made on the outer surface of the bushing (13) (e.g. 3-6 mm wide, 0.5-1 mm deep). In the wall of the bushing (13) there are several radial holes (15) (e.g. 2-4 holes with a diameter of 1.5-2.5 mm), which connect the annular groove (14) with the internal cavity of the bushing (13). The return spring (16) presses the bushing (13) towards the annular shoulder (11). The spring (16) is made of steel wire (e.g. 65G) and is designed for a compression force of 20-40 N in the working range. The radial hole (3) in the pin body is located opposite the cylindrical bushing (13) in such a way that when the bushing (13) is displaced downwards (under the action of the bending of the washer 12), the annular groove (14) is aligned with the radial hole (3), ensuring the passage of lubricant from the axial channel (5) to the outer surface of the pin through the spiral groove (4).

[0027] To fix the pin from axial displacement, a fixing element (17) is used, made in the form of an elongated metal plate, fixed at one end to the body (1) on the side of the plug (6) and located perpendicular to the axis of the body.

[0028] The device operates as follows. In the cold state (Fig. 3a), the pin temperature is below a predetermined threshold temperature. Spring (8) creates constant pressure on the lubricant in the reservoir (10) via piston (9). Return spring (16) presses sleeve (13) against the annular shoulder (11), while the radial hole (3) is blocked by sleeve (13). Grease does not reach the outer surface of the pin. The lubricant is located in reservoir (10) under pressure.

[0029] During operation of the unit, its temperature increases due to friction forces and the unit enters a heated state (Fig. 3b). When the hinge unit is heated to a predetermined threshold temperature (e.g. 40-50°C), the bimetallic washer (12) bends towards the bushing (13), displacing the bushing (13) downwards and compressing the return spring (16). The annular groove (14) aligns with the radial hole (3), opening a passage for the lubricant. The lubricant from the reservoir (10), under the pressure of the spring (8), enters through the central hole of the annular shoulder (11), then through the annular groove (14) and radial holes (15) of the bushing (13) into the radial hole (3) and further onto the spiral groove (4) and into the friction zone. The lubricant is supplied automatically as long as the temperature of the unit remains above the threshold value. This prevents the hinge joint from overheating. At the same time, the piston (9) gradually moves under the action of the spring (8), reducing the volume of the reservoir (10) as the lubricant is consumed.After the temperature drops below the threshold value, the washer (12) returns to its original shape, the return spring (16) lifts the sleeve (13) upward, pressing it against the annular shoulder (11), and closes the radial hole (3). The supply of lubricant stops.

[0030] When heated again, the lubrication path opens again, and spring (8) again squeezes out another portion of lubricant. The process is repeated many times until the lubricant in reservoir (10) runs out. When piston (9) reaches annular shoulder (11), the lubricant in reservoir (10) runs out. The operator pumps fresh lubricant by connecting an oiler to the opening (7) with a check valve. Lubricant fills reservoir (10), moving piston (9) to its extreme position, compressing spring (8) (Fig. 3c). The system is again ready for long-term operation.

[0031] Example of specific implementation.

[0032] The pin body (1) is made of 40X steel. The pin diameter was 60 mm, the length was 215 mm. The axial channel (5) had a diameter of 12 mm. The reservoir (10), formed by a part of the axial channel (5) between the piston (9) and the annular shoulder (11), had a length of 60 mm. The radial hole (3) was made with a diameter of 3 mm. The spiral groove (4) had a pitch of 12 mm, a depth of 1.5 mm, a width of 3 mm and was located in the middle third of the pin length (80 mm), not reaching the ends.The dimensions of the elements inside the axial channel (5) (sequentially from plug 2 to plug 6) were: threaded plug (2) - length 10 mm; spring (8) - made of 65G wire with a diameter of 1.5 mm, outer diameter 16 mm, length in free state 40 mm, compression force 50 N; piston (9) - made of 45 steel, outer diameter 17.9 mm (gap with channel 0.05 mm), length 20 mm; reservoir (10) - part of the channel 60 mm long; annular shoulder (11) - thickness 8 mm, central hole with a diameter of 6 mm; bimetallic washer (12) - made of TB 200 / 113 tape with a thickness of 0.5 mm, diameter 11.8 mm, temperature of the beginning of bending 38 ° C, full bending - 45 ° C. The washer is oriented so that when heated, it bends toward the bushing (13). The bushing (13) had an outside diameter of 11.96 mm (0.04 mm clearance with a channel) and a length of 25 mm. An annular groove (14) 4 mm wide and 0.8 mm deep, as well as three radial holes (15) with a diameter of 2 mm, were machined on the outer surface of the bushing.The return spring (16) is made of 65G wire with a diameter of 1 mm, an outer diameter of 10 mm, a length of 25 mm, and a compression force of 25 N. The threaded plug (6) was 15 mm long, had a central hole (7) with an M6×1.0 thread for connecting a grease nipple, and a built-in check valve. The locking element (17) was a metal plate 40 mm long, 15 mm wide, and 2 mm thick, secured to the housing (1) on the side of the plug (6). Litol-24 was used as a lubricant.

[0033] Tests have shown that lubricant consumption has decreased by at least 40% compared to the prototype, and the service life of the hinge has increased by 1.5 times.

[0034] Thus, the proposed utility model provides automatic supply of lubricant only when the unit reaches a predetermined threshold temperature, preventing overheating, reduces lubricant consumption compared to its continuous supply in the prototype and increases the service life of the hinge.

Claims

1. A hinge pin comprising a housing (1) with an outer cylindrical surface on which a spiral groove (4) is made for holding and distributing lubricant, an axial channel (5) for supplying lubricant is made inside the housing, and having a radial opening (3) connecting the axial channel (5) with the spiral groove (4), characterized in that the axial channel (5) is closed at one end by a threaded plug (2), and at the other end by a threaded plug (6) having a central opening (7) for supplying lubricant with a built-in check valve that ensures one-way passage of lubricant in the direction of the axial channel, wherein in the axial channel (5) from the plug (2) to the plug (6) a spring (8) is sequentially placed, pressing the piston (9) towards the annular shoulder (11), the piston (9), a reservoir (10) for lubricant located between the piston (9) and the annular shoulder (11), the annular shoulder (11) made in the axial channel (5),limiting the stroke of the piston (9) and having a central hole for the passage of lubricant; a heat-sensitive shut-off unit located on the side of the annular shoulder (11) opposite the piston (9) and consisting of sequentially arranged: a bimetallic washer (12) lying on the sleeve (13) and made with the possibility of bending when heated towards the sleeve (13), a cylindrical sleeve (13), on the outer surface of which an annular groove (14) is made, communicating with several radial holes (15) in the wall of the sleeve; wherein the radial hole (3) in the body of the pin is located opposite the cylindrical sleeve (13) in such a way that when the temperature of the pin is below the bending temperature of the bimetallic washer (12), the radial hole (3) is blocked by the sleeve (13), and when the temperature of the pin is above the bending temperature of the washer (12), the annular groove (14) is aligned with the radial hole (3) and ensures the passage of lubricant; the body (1) is provided with a fixing element (17),preventing axial displacement of the finger, 2. The pin of the articulated joint according to claim 1, characterized in that it contains a fixing element (17) made in the form of an elongated metal plate, secured at one end to the body (1) on the side of the plug (6) and located perpendicular to the axis of the body.

Images