A transmission mechanism for a hydraulic pump in an electric tool

Abstract

This utility model provides a transmission mechanism for a hydraulic pump in power tools, belonging to the field of mechanical technology. It solves the problem of high cost in existing transmission mechanisms for hydraulic pumps in power tools. This transmission mechanism includes an axially displaceable piston and a circumferentially rotating disk. The piston's outer wall has a circumferential limiting mechanism. The end face of the rotating disk facing the piston has a slide rail. The surface height of the slide rail in the axial direction changes periodically along the circumferential direction. The end face of the piston facing the rotating disk has a limiting groove, in which a steel ball is placed. The steel ball protrudes from the limiting groove and abuts against the slide rail. This utility model has advantages such as low cost.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical technology and relates to a transmission mechanism, particularly a transmission mechanism for a hydraulic pump of an electric tool. Background Technology

[0002] Hydraulic pumps for power tools require low speed, high torque, and minimization of overall size, thus demanding high levels of structural compactness and transmission efficiency.

[0003] To address the aforementioned problems, a transmission assembly and a reciprocating pump including the transmission assembly have been designed [Application No.: 202010788430.X; Publication No.: CN111981102A]. The transmission assembly includes a reciprocating member and a rotating member. The rotating member is configured to rotate relative to the reciprocating member to drive the reciprocating member to perform reciprocating motion. The rotating member is mounted on the bottom of the reciprocating member along the axial direction. One of the reciprocating member and the rotating member has symmetrically distributed protrusions. The other of the reciprocating member and the rotating member has a track portion. The protrusions are received in the track portion in a manner that allows them to slide within the track portion. The surface height of the track portion in the axial direction varies periodically along the circumferential direction of the track portion.

[0004] The aforementioned transmission assembly and the reciprocating pump including the transmission assembly reduce the assembly space and the overall volume, enabling the conversion between rotary motion and linear reciprocating motion in a compact space. However, the protrusion is a separate component fastened to the reciprocating member, or the protrusion and the reciprocating member are integrally formed. This makes the manufacturing of the protrusion and the reciprocating member inconvenient and costly. Moreover, when the protrusion wears out, the protrusion and the reciprocating member need to be replaced together, increasing the cost of use. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned problems in the existing technology by providing a transmission mechanism for a hydraulic pump in power tools that has low manufacturing and operating costs.

[0006] The objective of this utility model can be achieved through the following technical solution: A transmission mechanism for a hydraulic pump of an electric tool, comprising an axially displaced piston and a circumferentially rotating disk, wherein the outer wall of the piston has a circumferential limiting mechanism, and the end face of the rotating disk facing the piston has a slide rail, wherein the surface height of the slide rail in the axial direction varies periodically along the circumferential direction of the slide rail, characterized in that the end face of the piston facing the rotating disk has a limiting groove, wherein a steel ball is provided in the limiting groove, and the steel ball protrudes from the limiting groove and abuts against the slide rail.

[0007] In the aforementioned transmission mechanism for a hydraulic pump in an electric tool, the limiting groove is annular and coaxially arranged with the piston, the rotating disk has an outer ring located outside the slide rail, the outer diameter of the outer ring is equal to the outer diameter of the rotating disk, and the rotating disk also has an inner ring located inside the slide rail.

[0008] In the aforementioned transmission mechanism for a hydraulic pump in an electric tool, there are two steel balls located in a retainer. The retainer allows the two steel balls to be symmetrically arranged. The slide has symmetrically arranged trough and peak areas, with an angle of 90° between the trough and peak areas and spaced apart. The trough area transitions smoothly to the peak area via a slope or arc surface.

[0009] In the aforementioned transmission mechanism for a hydraulic pump in an electric tool, the piston has an axially protruding limiting post in the middle, the retainer is plate-shaped and sleeved on the limiting post, a retaining spring is embedded on the limiting post, and a washer located between the retainer and the retaining spring is sleeved on the limiting post. Both ends of the retainer are open slots, and steel balls are located in the corresponding open slots.

[0010] In the aforementioned transmission mechanism for a hydraulic pump in an electric tool, the circumferential limiting mechanism includes circumferentially distributed and axially penetrating grooves on the outer wall of the piston. Each groove is fitted with a limiting pin, and the limiting pin has a protruding part that protrudes from the groove.

[0011] In another scenario, in the aforementioned transmission mechanism for a hydraulic pump in a power tool, the circumferential limiting mechanism includes circumferentially distributed and axially extended limiting protrusions on the outer wall of the piston. In actual manufacturing, the inner wall of the piston sleeve has guide grooves matching the number of limiting protrusions. The outer end of the guide groove is open to allow the corresponding limiting protrusions to be inserted. The axial length of the guide groove is greater than the length of the limiting protrusions, thus achieving circumferential limiting and axial displacement of the piston.

[0012] Compared with existing technologies, the transmission mechanism for the hydraulic pump of this power tool has a compact structure, low manufacturing cost, and low operating cost. Attached Figure Description

[0013] Figure 1 This is an exploded view of the transmission mechanism for the hydraulic pump of this power tool.

[0014] Figure 2 This is a three-dimensional structural diagram of the rotating wheel in the transmission mechanism of the hydraulic pump of this power tool.

[0015] In the diagram, 1 is the piston; 11 is the limiting groove; 12 is the limiting pin; 13 is the slide; 2 is the rotating disk; 21 is the slide; 211 is the low zone; 212 is the high zone; 22 is the outer ring; 23 is the inner ring; 3 is the steel ball; 4 is the cage; 5 is the snap ring; 6 is the gasket; and 7 is the limiting pin. Detailed Implementation

[0016] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0017] like Figure 1 and Figure 2 As shown, the transmission mechanism for the hydraulic pump of this power tool includes an axially displaced piston 1 and a circumferentially rotating disk 2. The outer wall of the piston 1 has a circumferential limiting mechanism. The end face of the rotating disk 2 facing the piston 1 has a slide 21. The surface height of the slide 21 in the axial direction changes periodically along the circumferential direction of the slide 21. The end face of the piston 1 facing the rotating disk 2 has a limiting groove 11. A steel ball 3 is provided in the limiting groove 11. The steel ball 3 protrudes from the limiting groove 11 and abuts against the slide 21.

[0018] In the transmission mechanism of the hydraulic pump in this power tool, the back of piston 1, like in existing technology, is supported by a spring, which provides elastic force to cause piston 1 to tend to move axially towards the rotating disk 2, ensuring that steel ball 3 always contacts the slide 21. During operation, the rotating disk 2 rotates circumferentially, and the slide 21 of the rotating disk 2 provides contact for steel ball 3. Because the contact between slide 21 and steel ball 3 is a surface and point contact, the frictional force is insufficient to drive steel ball 3 to rotate around the axis of piston 1. Therefore, steel ball 3 remains stationary relative to the rotating disk 2. The change in surface height of slide 21 causes steel ball 3 to push piston 1 axially back and forth. Steel ball 3 is a purchased component, inexpensive, and not rigidly connected to piston 1, making installation convenient and reducing manufacturing costs. Moreover, when steel ball 3 wears out, only steel ball 3 needs to be replaced, without replacing piston 1 together, reducing operating costs.

[0019] To elaborate further, the limiting groove 11 is annular and coaxially arranged with the piston 1. The rotating disk 2 has an outer ring 22 located on the outer periphery of the slide 21, and the outer diameter of the outer ring 22 is equal to the outer diameter of the rotating disk 2. The rotating disk 2 also has an inner ring 23 located on the inner periphery of the slide 21. The limiting groove 11 is annular, which facilitates the installation of the steel ball 3. The arrangement of the outer ring 22 and the inner ring 23 not only ensures the structural strength of the rotating disk 2, but also limits the movement of the steel ball 3, ensuring operational stability.

[0020] There are two steel balls 3, and the two steel balls 3 are located in the retainer 4. The retainer 4 makes the two steel balls 3 symmetrically arranged. The slide 21 has a symmetrically arranged valley area 211 and a peak area 212. The angle between the valley area 211 and the peak area 212 is 90° and they are spaced apart. The valley area 211 transitions smoothly to the peak area 212 through a slope or arc surface. In this embodiment, the valley area 211 transitions smoothly to the peak area 212 through an arc surface. In this way, the retainer 4 prevents the steel balls 3 from shifting, has good structural symmetry, and good working stability.

[0021] The piston 1 has an axially protruding limiting post 12 in the middle. The retainer 4 is plate-shaped and sleeved on the limiting post 12. A retaining spring 5 is embedded in the limiting post 12. A gasket 6 is sleeved between the retainer 4 and the retaining spring 5 on the limiting post 12. Both ends of the retainer 4 are open slots, and the steel ball 3 is located in the corresponding open slots. In this way, the retainer 4 is positioned on the piston 1, the structure is stable, it prevents the steel ball 3 from shifting, reduces local wear caused by concentrated force on the steel ball 3, and extends the service life of the steel ball 3.

[0022] In this embodiment, the circumferential limiting mechanism includes three circumferentially distributed and axially penetrating grooves 13 on the outer wall of the piston 1. Each groove 13 is fitted with a limiting pin 7, which has a protruding portion protruding from the groove 13. The protruding portion is used to embed into the inner wall of the piston 1 sleeve, thus achieving circumferential limiting of the piston 1. The limiting pin 7 also plays a guiding role, ensuring smooth axial displacement of the piston 1.

[0023] Contents not described in detail herein are existing technologies known to those skilled in the art. The specific embodiments described herein are merely illustrative examples illustrating the spirit of this invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this invention or exceeding the scope defined by the appended claims.

Claims

1. A transmission mechanism for a hydraulic pump of a power tool, comprising an axially displaced piston (1) and a circumferentially rotating rotary disk (2), the outer wall of the piston (1) having a circumferential limiting mechanism, the end face of the rotary disk (2) facing the piston (1) having a slide (21), the surface height of the slide (21) in the axial direction periodically varying along the circumferential direction of the slide (21), characterized in that, The piston (1) has a limiting groove (11) on its end face facing the rotating disk (2). The limiting groove (11) contains a steel ball (3), which protrudes from the limiting groove (11) and abuts against the slide (21).

2. The transmission mechanism for a hydraulic pump in an electric tool according to claim 1, characterized in that, The limiting groove (11) is annular and coaxially arranged with the piston (1). The rotating disk (2) has an outer ring (22) located outside the slide (21). The outer diameter of the outer ring (22) is equal to the outer diameter of the rotating disk (2). The rotating disk (2) also has an inner ring (23) located inside the slide (21).

3. The transmission mechanism for a hydraulic pump in an electric tool according to claim 2, characterized in that, The number of steel balls (3) is two and the two steel balls (3) are located in the retainer (4). The retainer (4) makes the two steel balls (3) symmetrically arranged. The slide (21) has a valley area (211) and a peak area (212) symmetrically arranged. The angle between the valley area (211) and the peak area (212) is 90° and they are spaced apart. The valley area (211) smoothly transitions to the peak area (212) through a slope or arc surface.

4. The transmission mechanism for a hydraulic pump in an electric tool according to claim 3, characterized in that, The piston (1) has an axially protruding limiting post (12) in the middle. The retainer (4) is in the shape of a sheet and is sleeved on the limiting post (12). A retaining ring (5) is embedded on the limiting post (12). A gasket (6) is sleeved on the limiting post (12) between the retainer (4) and the retaining ring (5). Both ends of the retainer (4) are open slots, and the steel ball (3) is located in the corresponding open slot.

5. A transmission mechanism for a hydraulic pump in an electric tool according to claim 1, 2, 3, or 4, characterized in that, The circumferential limiting mechanism includes circumferentially distributed and axially penetrating grooves (13) on the outer wall of the piston (1), and each groove (13) is provided with a limiting pin (7), which has a protrusion protruding from the groove (13).

6. A transmission mechanism for a hydraulic pump in an electric tool according to claim 1, 2, 3, or 4, characterized in that, The circumferential limiting mechanism includes limiting protrusions that are evenly distributed circumferentially and extend axially on the outer wall of the piston (1).

Images