CN218082462U

CN218082462U - Adjustable clutch and electric screwdriver

Info

Publication number: CN218082462U
Application number: CN202221540768.4U
Authority: CN
Inventors: 付政; 周飞; 芮正国; 唐蓓
Original assignee: Oechsler Plastic Products Taicang Co Ltd
Current assignee: Oechsler Plastic Products Taicang Co Ltd
Priority date: 2022-06-20
Filing date: 2022-06-20
Publication date: 2022-12-20
Anticipated expiration: 2032-06-20

Abstract

The utility model belongs to the technical field of mechanical transmission, concretely relates to adjustable variable clutch and electric screwdriver. The clutch comprises a first rotating shaft, a first friction plate disc, a second friction disc, a thermal expansion unit and a second rotating shaft which are coaxially arranged in sequence, and further comprises a bracket capable of limiting the distance between the first rotating shaft and the second rotating shaft; the first rotating shaft and the second rotating shaft are respectively and rotatably arranged on the support, the first friction disc is fixedly connected with the first rotating shaft, and the second friction disc and the second rotating shaft are respectively and fixedly connected with two ends of the thermal expansion unit; when the thermal expansion unit is heated, the axial dimension increases, and the first friction plate disc and the second friction plate are forced to contact and press each other. The clutch has the advantages of small structure volume, large transferable torque, continuously adjustable maximum torque in a large range, small vibration and low noise during working, and higher reliability and good controllability.

Description

Adjustable clutch and electric screwdriver

Technical Field

The utility model belongs to the technical field of mechanical transmission, concretely relates to adjustable variable clutch and electric screwdriver.

Background

Clutches are a type of transmission that may be connected in series in a power transmission path to change or limit the power connection between upstream and downstream. The mechanical clutch is the most widely used clutch, and is switched by a pure mechanical structure, the structure is reliable, the power transmission is direct, but due to the inherent characteristics of the mechanical structure, noise and vibration are easily generated when the clutch state is switched, and the clutch has obvious clamping and stagnation feeling. In addition, the degree of freedom of regulation and control of the mechanical clutch on the clutch force is small, and multi-stage regulation and control and continuous regulation and control are difficult to realize. The electromagnetic clutch is a clutch which is used more and more in recent years, the power connection state is regulated and controlled by changing a coil magnetic field to control the on-off of friction plates and changing the pressure between the friction plates, and compared with mechanical clutch, the regulation and control mode is smoother, the noise and vibration are lower, but the electromagnetic clutch is higher in cost and insufficient in reliability. In addition, the electromagnetic clutch generates clutch acting force by means of electromagnetic induction, the clutch acting force is limited in size, and large torque is difficult to transmit.

SUMMERY OF THE UTILITY MODEL

Not enough to prior art exists, the utility model provides an adjustable clutch to further provide an electric screwdriver on this basis.

The utility model provides an adjustable clutch, which comprises a first rotating shaft, a first friction plate disc, a second friction disc, a thermal expansion unit, a second rotating shaft and a bracket, wherein the first rotating shaft, the first friction plate disc, the second friction disc, the thermal expansion unit and the second rotating shaft are coaxially arranged in sequence; the first rotating shaft and the second rotating shaft are respectively and rotatably arranged on the support, the first friction disc is fixedly connected with the first rotating shaft, and the second friction disc and the second rotating shaft are respectively and fixedly connected to two ends of the thermal expansion unit; when the thermal expansion unit is not heated, the first friction plate disc and the second friction disc are separated from each other; when the thermal expansion unit is heated, the axial dimension increases, and the first friction plate disc and the second friction plate are forced to contact and press each other.

Further, the thermal expansion unit comprises a cylinder body, a piston which is in sliding fit in the cylinder body, a heating assembly which can heat the cylinder body, and a thermal expansion medium which is filled in a cavity between the cylinder body and the piston; the heating assembly heats and expands the thermal expansion medium, so that the piston is pushed to move in the direction away from the cylinder body.

Further, the thermal expansion medium is a liquid thermal expansion medium.

Further, the heating assembly comprises an electric heating film, a first annular electrode, a second annular electrode, a first electric brush and a second electric brush, wherein the electric heating film is wrapped on the periphery of the cylinder body and rotates along with the cylinder body; the electric heating film is heated by supplying electricity between the first brush and the second brush.

Further, the piston is fixed on the back surface of the second friction disc, and the closed end of the cylinder body is fixed on the second rotating shaft; a group of convex blocks are arranged at the opening of the cylinder body, and a group of notches are arranged on the back surface of the second friction disk; the projection is inserted into the recess to transmit torque.

Further, the periphery of the piston is hooped with one or more sealing rings.

Furthermore, the bracket comprises a first end panel and a second end panel which are oppositely arranged, and a group of connecting rods which are fixedly connected between the first end panel and the second end panel; the centers of the first end panel and the second end panel are respectively provided with a shaft hole, the first rotating shaft is connected to the first end panel in a rotating fit mode, and the second rotating shaft is connected to the second end panel in a rotating fit mode.

Furthermore, a first thrust bearing is arranged on the first rotating shaft and is positioned between the first end panel and the first friction sheet disc; the second rotating shaft is also provided with a second thrust bearing, and the second thrust bearing is positioned between the second end face plate and the cylinder body.

The utility model provides an electric screwdriver is including the motor that is in power upper reaches end and the screwdriver axle that is in power lower reaches end, and the screwdriver axle tip has the interchangeable formula screwdriver head of magnetism of inhaling, has concatenated above-mentioned adjustable variable clutch on the transmission path between motor and screwdriver axle.

Furthermore, a speed change gear box is connected in series between the adjustable clutch and the motor or between the adjustable clutch and the screwdriver shaft.

Has the advantages that: compared with the prior art, the utility model provides an adjustable clutch, the structure is small, but the transmission moment of torsion is big, and the maximum torque of transmission can be in continuous modulation on a large scale, and the during operation vibrates the noise for a short time and is low, has higher reliability and good controllability. The utility model provides an electric screwdriver can effectively prevent to take place smooth tooth and destroy when twisting the screw.

Drawings

Fig. 1 is a schematic structural diagram of an adjustable clutch.

Fig. 2 is an exploded view of a transmission arrangement in the variable clutch.

Fig. 3 is a schematic structural view of the heating assembly.

Fig. 4 is a schematic view of the engagement between the notch and the bump.

In the drawing, a first rotating shaft 1, a first friction plate disk 2, a second friction disk 3, a thermal expansion unit 4, a second rotating shaft 5, a cylinder 41, a piston 42, a heating unit 43, an electric heating film 431, a first annular electrode 432, a second annular electrode 433, a first brush 434, a second brush 435, a projection 411, a recess 31, a seal ring 44, a first end plate 91, a second end plate 92, a connecting rod 93, a first thrust bearing 6, and a second thrust bearing 7 are shown.

Detailed Description

The invention is further illustrated by the following examples, which are intended to illustrate the technical solutions of the invention more clearly and are not to be construed as a limitation.

Unless defined otherwise, technical or scientific terms used herein should be understood as having the ordinary meaning as understood by those of ordinary skill in the art. The use of "first," "second," and similar terms in the description herein do not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item preceding the word comprises the element or item listed after the word and its equivalent, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used only to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

Example 1

The adjustable clutch shown in fig. 1 comprises a first rotating shaft 1, a first friction plate 2, a second friction disc 3, a thermal expansion unit 4, a second rotating shaft 5, and a bracket capable of limiting the distance between the first rotating shaft 1 and the second rotating shaft 5, which are coaxially arranged in sequence; the first rotating shaft 1 and the second rotating shaft 5 are respectively and rotatably arranged on the support, the first friction plate disc 2 is fixedly connected with the first rotating shaft 1, and the second friction disc 3 and the second rotating shaft 5 are respectively and fixedly connected with two ends of the thermal expansion unit 4; when the thermal expansion unit 4 is not heated, the first friction plate disc 2 and the second friction disc 3 are separated from each other; when the thermal expansion unit 4 is heated, the axial dimension increases, forcing the first friction plate disc 2 and the second friction plate 3 to contact and press each other. The adjustable clutch controls the first friction plate disc 2 and the second friction disc 3 to separate and contact through the thermal expansion unit 4, so that the power connection state between the first rotating shaft 1 and the second rotating shaft 5 can be conveniently controlled, and the controllable clutch function is realized. Since the compressive force generated by thermal expansion of the material can be very large and can be much larger than the electromagnetic force, the torque that such a clutch can transmit at the same volume is much larger than that of an electromagnetic clutch.

As shown in fig. 2, the thermal expansion unit 4 includes a cylinder 41, a piston 42 slidably fitted in the cylinder 41, a heating unit 43 capable of heating the cylinder 41, and a thermal expansion medium filled in a cavity between the cylinder 41 and the piston 42; the thermal expansion medium is in a cooling state when the heating assembly 43 is not operated, and the first friction plate disc 2 and the second friction plate disc 3 are separated from each other; the heating assembly 43 operates to thermally expand the thermal expansion medium, thereby urging the piston 42 in a direction away from the cylinder block 41 to compress the first and

second friction plates

2, 3 against each other. Preferably, the thermal expansion medium is a liquid thermal expansion medium, such as a non-toxic and non-flammable liquid.

As shown in fig. 3, the heating unit 43 includes an electric heating film 431 wrapped around the cylinder 41 and rotating with the cylinder 41, a first annular electrode 432 and a second annular electrode 433 fixed to both ends of the electric heating film 431, a first brush 434 elastically contacting the first annular electrode 432, and a second brush 435 elastically contacting the second annular electrode 433; the first brush 434 and the second brush 435 are fixed to an insulating holder mounted on the bracket. The electric heating film 431 may be made of a graphene thin film material, the first ring-shaped electrode 432 and the second ring-shaped electrode 433 may be made of copper electrodes, and when heating is needed, the electric heating film 431 is heated by supplying power between the first brush 434 and the second brush 435, and is conducted to a thermal expansion medium to expand the thermal expansion medium. In addition, the heating power can be adjusted by changing the current, so that the temperature of the thermal expansion medium is adjusted, the extrusion force between the first friction plate disc 2 and the second friction disc 3 is adjusted, and the maximum torque transmitted between the first rotating shaft 1 and the second rotating shaft 5 is adjusted. This adjustment has the advantages of smooth switching of power connection and disconnection, minimal vibration and noise, and continuous modulation of the maximum torque transmitted from zero to a large value.

As an alternative, the electric heating film 431 in the heating assembly 43 may be replaced by an electric heating coil, for example, a resistance wire with an insulating wrapping is spirally wound on the surface of the cylinder 41, and both ends of the resistance wire are electrically connected to the first annular electrode 432 and the second annular electrode 433, respectively. The resistance wire can be made of constantan (konstan alloy), constantan alloy, zinc cupronite, nickel-chromium alloy or copper-nickel alloy, and the section and the number of winding turns of the resistance wire can be changed to obtain different resistance values so as to adapt to different application scenes.

As shown in fig. 4, the piston 42 is fixed to the back surface of the second friction disk 3, and the closed end of the cylinder block 41 is fixed to the second rotating shaft 5; a group of convex blocks 411 are arranged at the opening of the cylinder body 41, and a group of concave openings 31 are arranged on the back surface of the second friction disc 3; the protrusion 411 is inserted into the recess 31 to transmit torque.

As shown in fig. 2 and 4, the piston 42 is circumferentially banded with one or more sealing rings 44 to prevent leakage of the thermal expansion medium.

As shown in fig. 1, the bracket includes a first end plate 91 and a second end plate 92 which are oppositely arranged, and further includes a set of connecting rods 93 which are fixedly connected between the first end plate 91 and the second end plate 92; the centers of the first end plate 91 and the second end plate 92 are provided with shaft holes, the first rotating shaft 1 is connected to the first end plate 91 in a rotating fit manner, and the second rotating shaft 5 is connected to the second end plate 92 in a rotating fit manner.

As shown in fig. 2, the first rotating shaft 1 is further provided with a first thrust bearing 6, and the first thrust bearing 6 is located between the first end panel 91 and the first friction plate disc 2; the second shaft 5 is further provided with a second thrust bearing 7, and the second thrust bearing 7 is located between the second end plate 92 and the cylinder block 41. Through setting up first thrust bearing 6 and second thrust bearing 7, both can reduce the rotational resistance of first pivot 1 and second pivot 5, can make and produce very big extrusion force again between first friction disc dish 2 and the second friction disk 3, guarantee that the moment of torsion is adjustable in a large scale.

Example 2

The adjustable clutch of the embodiment 1 is based on the adjustable clutch of the embodiment 1, and the electric screwdriver comprises a motor at the upstream end of power and a screwdriver shaft at the downstream end of the power, wherein the end part of the screwdriver shaft is provided with a replaceable magnetic-type screwdriver bit, and the adjustable clutch of the embodiment 1 is connected in series on a transmission path between the motor and the screwdriver shaft. Furthermore, a speed change gear box is connected in series between the adjustable clutch and the motor or between the adjustable clutch and the screwdriver shaft. When the electric screw driver of the present embodiment is used, the amount of heat generation of the heating unit 43, i.e., the supply current between the first brush 434 and the second brush 435, is adjusted according to the torque required for screwing, and the supply current is increased when the torque required for screwing is large and decreased when the torque required for screwing is small. The required torque is gradually increased as the screw is gradually tightened, and when the maximum torque defined by the clutch is exceeded, the first friction plate disc 2 and the second friction plate 3 slip, so that the screw and the screw hole are protected, and the sliding teeth are prevented from being damaged.

The above embodiments are exemplary and are intended to illustrate the technical concept and features of the present invention so that those skilled in the art can understand the contents of the present invention and implement the present invention, and the protection scope of the present invention cannot be limited thereby. All equivalent changes and modifications made according to the spirit of the present invention should be covered by the protection scope of the present invention.

Claims

1. An adjustable clutch, comprising: the friction disc type friction disc comprises a first rotating shaft (1), a first friction plate disc (2), a second friction disc (3), a thermal expansion unit (4) and a second rotating shaft (5) which are coaxially arranged in sequence, and further comprises a support capable of limiting the distance between the first rotating shaft (1) and the second rotating shaft (5); the first rotating shaft (1) and the second rotating shaft (5) are respectively rotatably mounted on the support, the first friction plate disc (2) is fixedly connected with the first rotating shaft (1), and the second friction disc (3) and the second rotating shaft (5) are respectively fixedly connected to two ends of the thermal expansion unit (4); when the thermal expansion unit (4) is not heated, the first friction plate disc (2) and the second friction disc (3) are separated from each other; when the thermal expansion unit (4) is heated, the axial size is increased, and the first friction plate disc (2) and the second friction plate disc (3) are forced to contact with each other and are pressed.

2. The tunable clutch of claim 1, wherein: the thermal expansion unit (4) comprises a cylinder body (41), a piston (42) which is in sliding fit in the cylinder body (41), a heating assembly (43) which can heat the cylinder body (41), and a thermal expansion medium which is filled in a cavity between the cylinder body (41) and the piston (42); the heating assembly (43) heats and expands the thermal expansion medium, so that the piston (42) is pushed to move away from the cylinder (41).

3. The tunable clutch of claim 2, wherein: the thermal expansion medium is a liquid thermal expansion medium.

4. The tunable clutch of claim 2, wherein: the heating assembly (43) comprises an electric heating film (431) which is wrapped on the circumferential side of the cylinder body (41) and rotates along with the cylinder body (41), a first annular electrode (432) and a second annular electrode (433) which are fixed at two ends of the electric heating film (431), a first brush (434) which is elastically contacted with the first annular electrode (432), and a second brush (435) which is elastically contacted with the second annular electrode (433); the electric heating film (431) is heated by supplying electricity between the first brush (434) and the second brush (435).

5. The variable clutch of claim 2, wherein: the piston (42) is fixed on the back surface of the second friction disc (3), and the closed end of the cylinder body (41) is fixed on the second rotating shaft (5); a group of convex blocks (411) are arranged at the opening of the cylinder body (41), and a group of notches (31) are arranged on the back surface of the second friction disc (3); the projection (411) engages in the recess (31) to transmit torque.

6. The variable clutch of claim 2, wherein: the periphery of the piston (42) is hooped with one or more sealing rings (44).

7. The variable clutch of claim 2, wherein: the bracket comprises a first end panel (91) and a second end panel (92) which are oppositely arranged, and further comprises a group of connecting rods (93) fixedly connected between the first end panel (91) and the second end panel (92); first terminal surface board (91) and second terminal surface board (92) central authorities all are equipped with the shaft hole, first pivot (1) normal running fit is connected on first terminal surface board (91), second pivot (5) normal running fit is connected on second terminal surface board (92).

8. The variable clutch of claim 7, wherein: the first rotating shaft (1) is also provided with a first thrust bearing (6), and the first thrust bearing (6) is positioned between the first end panel (91) and the first friction sheet disc (2); the second rotating shaft (5) is further provided with a second thrust bearing (7), and the second thrust bearing (7) is located between the second end face plate (92) and the cylinder body (41).

9. An electric screwdriver, includes the motor that is in power upstream end and is in the screwdriver axle of power downstream end, screwdriver axle tip has the formula screwdriver head of replaceable magnetism, its characterized in that: an adjustable clutch as claimed in any one of claims 1 to 8 is connected in series in the drive path between the motor and the screwdriver shaft.

10. The electric screwdriver according to claim 9, wherein: a speed change gear box is connected in series between the adjustable clutch and the motor or between the adjustable clutch and the screwdriver shaft.