Gear box structure of hydraulic rock drill

Abstract

The utility model relates to the technical field of hydraulic rock drills, in particular to a gearbox structure of a hydraulic rock drill, which comprises a box body, a driving wheel and a driven wheel which are meshed with each other are arranged in the box body, and the driven wheel is used for connecting a bit shank; the hydraulic motor is detachably connected with the box body, the hydraulic motor is provided with an output shaft, and the output shaft is connected with the driving wheel and drives the driving wheel to rotate; wherein the driving wheel is provided with a cooling channel through which oil passes, the output shaft is located at the first end of the cooling channel, and the driven wheel is located at the second end of the cooling channel; the box body is provided with a backflow channel, and the backflow channel is communicated with the cooling channel; the cooling channel is arranged on the driving wheel, and liquid hydraulic oil effectively cools the driving wheel through the cooling channel, so that higher temperature is prevented from being generated in the box body.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic rock drill technology, and in particular to a gearbox structure for a hydraulic rock drill. Background Technology

[0002] Hydraulic rock drills, as core equipment for modern rock breaking, are widely used in mining and rock drilling, tunnel excavation, water conservancy projects, and infrastructure construction. Their advantages, such as high efficiency, environmental friendliness, and strong controllability, have gradually replaced traditional pneumatic rock drilling equipment. Their core function is to convert the continuous high-pressure hydraulic energy provided by the hydraulic system into high-frequency, high-impact reciprocating motion of the piston against the drill bit, achieving effective breaking of hard rock. In this energy conversion and transmission chain, the gearbox is one of the core transmission components, mainly undertaking key functions such as power transmission, speed conversion, and torque adjustment.

[0003] The gearbox contains a gear set that reduces the high speed of the hydraulic motor to a low speed suitable for rock drilling, while simultaneously amplifying the torque to ensure the drill rod can rotate stably against rock resistance. The meshing of gears and the operation of bearings in the gearbox generate a significant amount of heat. Poor heat dissipation in the confined space will cause a sharp rise in oil temperature, leading to oil deterioration, decreased viscosity, lubrication failure, and ultimately, accelerated wear and even sintering.

[0004] In actual production, some users add grease to the gearbox. While adding grease can reduce friction between gears and bearings, it doesn't remove heat from the gearbox, resulting in continued gearbox overheating, especially at higher speeds. To address this, some technicians have adopted aerosol lubrication (also known as oil-air lubrication). This involves mixing a small amount of lubricating oil with compressed air to form a fine mist two-phase flow, which is then precisely sprayed onto the meshing surfaces of gears, bearings, and other critical friction pairs to achieve lubrication, cooling, and cleaning. However, implementing aerosol lubrication requires designing complex flow channels to ensure effective lubrication at all points, increasing the difficulty of parts processing and production costs. Utility Model Content

[0005] In view of the shortcomings or problems existing in the prior art, this disclosure provides a gearbox structure for a hydraulic rock drill. The gearbox structure is simple and can effectively play the role of lubrication and cooling.

[0006] The technical solution adopted by this disclosure to solve the above-mentioned technical problem is: a gearbox structure for a hydraulic rock drill, comprising:

[0007] The housing contains a driving wheel and a driven wheel that mesh with each other, the driven wheel being used to connect to the drill bit.

[0008] A hydraulic motor is detachably connected to the housing. The hydraulic motor is equipped with an output shaft, which is connected to a drive wheel and drives the drive wheel to rotate.

[0009] The driving wheel has a cooling channel through which oil is supplied, the output shaft is located at the first end of the cooling channel, and the driven wheel is located at the second end of the cooling channel.

[0010] The housing is equipped with a return flow channel, which is connected to the cooling channel.

[0011] In a preferred embodiment, a fitting gap is provided between the driving wheel and the driven wheel, and the fitting gap is connected to the cooling channel and the return channel, respectively.

[0012] The clearance between the drive and driven wheels can prevent them from jamming or being forcibly engaged during operation. On the other hand, it allows oil to pass through, improving cooling and lubrication.

[0013] In a preferred embodiment, the cooling channel is inclinedly arranged on the drive wheel.

[0014] Compared to a vertical arrangement, an inclined cooling channel design makes it easier for the cooling oil to enter the mating clearance and then the meshing surface. The inclined design effectively extends the cooling oil's path and residence time in high-temperature, high-friction areas, allowing the oil to continuously carry away heat and achieve better cooling results.

[0015] In a preferred embodiment, the system also includes an oil tank, and the return channel is connected to the oil inlet of the oil tank.

[0016] In a preferred embodiment, the first end of the output shaft is connected to the drive wheel, and the second end of the output shaft is connected to the oil outlet of the oil tank.

[0017] In a preferred embodiment, the housing is provided with a first mounting cavity and a second mounting cavity, the driving wheel is located in the first mounting cavity, and the driven wheel is located in the second mounting cavity.

[0018] In a preferred embodiment, the first mounting cavity is provided with at least one first bearing, which is arranged along the axial direction of the drive wheel, and the drive wheel is mounted in the first mounting cavity through the first bearing.

[0019] In a preferred embodiment, the second mounting cavity is provided with at least one second bearing, which is arranged along the axial direction of the driven wheel, and the driven wheel is mounted in the second mounting cavity through the second bearing.

[0020] At least one first bearing is arranged along the axial direction of the driving wheel, and at least one second bearing is arranged along the axial direction of the driven wheel to form a span support, thereby improving the bending deformation resistance of the driving wheel and the driven wheel and avoiding uneven load, tooth end stress concentration and abnormal wear caused by deformation.

[0021] In a preferred embodiment, the hydraulic motor is connected to the housing by bolts or screws.

[0022] In a preferred embodiment, the first mounting cavity is provided with at least one first annular groove, and a first sealing ring is provided in the first annular groove.

[0023] In a preferred embodiment, the second mounting cavity is provided with at least one second annular groove, and a second sealing ring is provided in the second annular groove.

[0024] Compared with the prior art, the beneficial effects of this utility model are as follows: By setting the cooling channel on the drive wheel, the liquid hydraulic oil effectively cools the drive wheel through the cooling channel, thereby avoiding high temperatures inside the gearbox; as the main heat-generating component, the drive wheel directly cools the core heat-generating component, which can effectively reduce the working temperature of the gear and prevent failures such as tooth surface scuffing and peeling caused by overheating; by setting the cooling channel directly on the drive wheel, the existing structural space is fully utilized, reducing additional space occupation, making the structure simpler and more reliable, and reducing possible leakage points and failure points; the technical solution of this application has a compact and reliable structure, which can effectively lubricate and cool the drive wheel and driven wheel, preventing local high temperatures. Attached Figure Description

[0025] Figure 1 This is a cross-sectional view of the gearbox structure of the hydraulic rock drill of this utility model;

[0026] Figure 2 This utility model Figure 1 A magnified view of a section at point A in the middle;

[0027] Figure 3 This utility model Figure 1 A magnified view of a section at point B.

[0028] In the diagram: 1. Housing; 2. Hydraulic motor; 3. Drive wheel; 4. Driven wheel; 5. Output shaft; 6. Oil tank; 7. Cooling channel; 8. Return channel; 9. Fit clearance; 10. Reversing valve; 12. First bearing; 13. Second bearing; 14. First sealing ring; 15. Second sealing ring. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] Please refer to Figures 1-3 As shown, this application discloses a gearbox structure for a hydraulic rock drill, including a housing 1 and a hydraulic motor 2. The housing 1 contains a meshing drive wheel 3 and a driven wheel 4. The driven wheel 4 is used to connect to the drill bit shank. The hydraulic motor 2 is detachably connected to the housing 1. Specifically, the hydraulic motor 2 is connected to the housing 1 by bolts or screws. The hydraulic motor 2 has an output shaft 5, which is connected to the drive wheel 3 and drives the drive wheel 3 to rotate. The drive wheel 3 has a cooling channel 7 for supplying hydraulic fluid. The output shaft 5 is located at the first end of the cooling channel 7, and the driven wheel 4 is located at the second end of the cooling channel 7. The height of the first end of the cooling channel 7 is lower than the height of the second end of the cooling channel 7. The housing 1 has a return channel 8, which communicates with the cooling channel 7. In this application, the hydraulic fluid is preferably liquid hydraulic oil. In gear transmissions, the driving gear 3 (especially the pinion) typically operates at high speeds, and its teeth frequently mesh with the driven gear 4, bearing significant contact stress and sliding friction. It is one of the main sources of heat generation. This application integrates the cooling channel 7 directly inside the driving gear 3, effectively placing the cooling channel 7 in the area most in need of heat dissipation. Oil flows through the cooling channel 7 inside the driving gear 3, engaging in large-area, direct heat exchange with the high-temperature gear body (especially the tooth roots and hub area), resulting in high cooling efficiency and a good cooling effect. Furthermore, the output shaft 5 is located at the first end of the cooling channel 7, and the oil enters from the first end of the cooling channel 7. The output shaft 5 has a relatively low temperature, ensuring that the oil entering the cooling channel 7 has a lower temperature, thus better cooling the driving gear 3 and the driven gear 4.

[0031] A clearance 9 is provided between the driving gear 3 and the driven gear 4, which connects to the cooling channel 7 and the return channel 8. The clearance 9 serves two purposes: firstly, it prevents the driving gear 3 and the driven gear 4 from jamming or being forcibly engaged during operation; secondly, it allows oil to pass through, improving cooling and lubrication. The gear meshing point is another location in the entire transmission system with intense friction and high temperature rise. The clearance 9 acts as a "bridge" between the cooling channel 7 and the return channel 8. When the oil in the cooling channel 7 passes through the clearance 9, it is forcibly transported to the friction interface, thereby lubricating and cooling the meshing point of the driving gear 3 and the driven gear 4, as well as the driven gear 4 itself.

[0032] Understandably, in this application, the size of the driving gear 3 is smaller than that of the driven gear 4 (i.e., the diameter of the driving gear 3 is smaller than that of the driven gear 4). Since the output shaft 5 directly acts on the driving gear 3, the smaller size of the driving gear 3 results in fewer teeth, greater tooth root thickness, and stronger load-bearing capacity per unit tooth width. This allows it to withstand the impact and load brought by high-frequency meshing, thus ensuring structural strength. The smaller size of the driving gear 3 also saves more space. When the driving gear 3 (small gear) drives the driven gear 4 (large gear) to rotate, it can effectively convert the input high speed to low speed and output a larger torque, converting the high speed of the hydraulic motor 2 into a low speed suitable for rock drilling operations, ensuring that the drill bit can overcome rock resistance and rotate stably.

[0033] Specifically, the cooling channel 7 is inclinedly positioned on the driving wheel 3, with its second end located at the front end of the meshing point between the driving wheel 3 and the driven wheel 4. This second end of the cooling channel 7 is the oil outlet, and its location at the front end of the meshing point allows the oil to spread from the front of the teeth to the entire meshing surface, resulting in wider oil coverage and better lubrication and cooling. Compared to a vertical arrangement, the inclined configuration of the cooling channel 7 makes it easier for the oil to enter the mating clearance 9 and then the meshing surface. The inclined cooling channel 7 effectively extends the path and residence time of the cooling oil in the high-temperature, high-friction area, allowing the oil to continuously carry away heat and achieve a better cooling effect.

[0034] Furthermore, it also includes an oil tank 6, with a return channel 8 connected to the oil inlet of the oil tank 6. The first end of the output shaft 5 is connected to the drive wheel 3 via a spline, and the second end of the output shaft 5 is connected to the oil outlet of the oil tank 6. The hydraulic oil in the oil tank 6 is transported along the output shaft 5 to the cooling channel 7. That is, the oil in the oil tank 6 passes sequentially through the oil outlet, output shaft 5, cooling channel 7, fitting clearance 9, and return channel 8, finally returning to the oil tank 6 through the oil inlet, forming a closed-loop oil circuit. To better transport the hydraulic oil to the cooling channel 7, a guide channel can be provided along the axial direction of the output shaft 5. By utilizing the output shaft 5 itself as the oil transport channel, the complex external pipeline from the oil tank 6 to the cooling channel 7 is eliminated, greatly simplifying the system structure, reducing potential leakage points (external pipe joints, rotary seals), and improving the system's sealing reliability, especially suitable for the severe vibration environment of rock drills.

[0035] The hydraulic motor 2 is connected to a hydraulic pump and a reversing valve 10. The hydraulic pump draws in oil and outputs high-pressure oil to the reversing valve 10. The reversing valve 10 controls the output shaft 5 to rotate forward or backward. The working mechanism of the hydraulic motor 2, the hydraulic pump and the reversing valve 10 is existing technology and will not be described in detail here.

[0036] In one embodiment of this disclosure, the housing 1 is provided with a first mounting cavity and a second mounting cavity. A hydraulic motor 2 is located on one side of the first mounting cavity, a drive wheel 3 is located in the first mounting cavity, and a driven wheel 4 is located in the second mounting cavity. The first mounting cavity is provided with two first bearings 12, which are arranged axially along the drive wheel 3. The drive wheel 3 is mounted in the first mounting cavity via the first bearings 12. The second mounting cavity is provided with two second bearings 13, which are arranged axially along the driven wheel 4. The driven wheel 4 is mounted in the second mounting cavity via the second bearings 13. When the hydraulic rock drill is working, the huge impact reaction force transmitted from the drill bit is transmitted to the driven wheel 4 and the drive wheel 3. The two first bearings 12 arranged axially along the drive wheel 3 and the two second bearings 13 arranged axially along the driven wheel 4 form a span support, thereby improving the bending deformation resistance of the drive wheel 3 and the driven wheel 4 and avoiding uneven loading, tooth end stress concentration, and abnormal wear caused by deformation. Furthermore, the rigid support provided by the first bearing 12 ensures minimal deformation of the drive wheel 3 under thermal load, maintaining the precise relative position of the cooling channel 7 outlet and the engagement point, thereby enabling the oil to accurately cool the engagement point. Preferably, to provide better support, one of the first bearings 12 is located at the opening of the first mounting cavity, near the connection between the output shaft 5 and the drive wheel 3.

[0037] To enhance the sealing effect, the first mounting cavity is provided with at least one first annular groove, and a first sealing ring 14 is provided in the first annular groove; the second mounting cavity is provided with at least one second annular groove, and a second sealing ring 15 is provided in the second annular groove.

Claims

1. A gearbox structure for a hydraulic rock drill, characterized in that, include: The housing (1) is provided with a driving wheel (3) and a driven wheel (4) that mesh with each other. The driven wheel (4) is used to connect the drill bit. A hydraulic motor (2) is detachably connected to the housing (1). The hydraulic motor (2) is provided with an output shaft (5). The output shaft (5) is connected to the drive wheel (3) and drives the drive wheel (3) to rotate. The driving wheel (3) has a cooling channel (7) through which oil is supplied, the output shaft (5) is located at the first end of the cooling channel (7), and the driven wheel (4) is located at the second end of the cooling channel (7). The housing (1) is provided with a return channel (8), which is connected to the cooling channel (7).

2. The gearbox structure of the hydraulic rock drill according to claim 1, characterized in that, A fitting gap (9) is provided between the driving wheel (3) and the driven wheel (4), and the fitting gap (9) is connected to the cooling channel (7) and the return channel (8) respectively.

3. The gearbox structure of the hydraulic rock drill according to claim 1, characterized in that, The cooling channel (7) is inclinedly arranged on the drive wheel (3).

4. The gearbox structure of the hydraulic rock drill according to claim 1, characterized in that, It also includes an oil tank (6), and the return channel (8) is connected to the oil inlet of the oil tank (6).

5. The gearbox structure of the hydraulic rock drill according to claim 4, characterized in that, The first end of the output shaft (5) is connected to the drive wheel (3), and the second end of the output shaft (5) is connected to the oil outlet of the oil tank (6).

6. The gearbox structure of the hydraulic rock drill according to claim 1, characterized in that, The housing (1) is provided with a first mounting cavity and a second mounting cavity. The driving wheel (3) is located in the first mounting cavity, and the driven wheel (4) is located in the second mounting cavity.

7. The gearbox structure of the hydraulic rock drill according to claim 6, characterized in that, The first mounting cavity is provided with at least one first bearing (12), which is arranged along the axial direction of the drive wheel (3), and the drive wheel (3) is mounted in the first mounting cavity through the first bearing (12).

8. The gearbox structure of the hydraulic rock drill according to claim 6, characterized in that, The second mounting cavity is provided with at least one second bearing (13), which is arranged along the axial direction of the driven wheel (4), and the driven wheel (4) is mounted in the second mounting cavity through the second bearing (13).

9. The gearbox structure of the hydraulic rock drill according to claim 1, characterized in that, The hydraulic motor (2) is connected to the housing (1) by bolts or screws.

10. The gearbox structure of the hydraulic rock drill according to claim 6, characterized in that, The first mounting cavity is provided with at least one first annular groove, and a first sealing ring (14) is provided in the first annular groove; the second mounting cavity is provided with at least one second annular groove, and a second sealing ring (15) is provided in the second annular groove.

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