CN214465940U - Output shaft assembly and motor using same - Google Patents

Abstract

The utility model discloses an output shaft assembly and a motor using the same, which comprises an output shaft and a gear injection molding body, wherein the output shaft assembly is formed by the output shaft through insert injection molding in a gear injection molding body mold; and a shoulder is arranged on the shaft section of the output shaft which is in contact with the gear injection molding body, and the ratio of the radial thickness H4 of the gear injection molding body to the diameter H5 of the shoulder is 3/10-8/3. Output shaft subassembly insert injection moulding in gear injection moulding body mould by the output shaft, mould plastics through the inserts and make production frictional force and snap-in force between output shaft and the gear injection moulding body to become the mechanism of protection broken tooth in the motor, can guarantee the mechanical strength of output shaft subassembly simultaneously, greatly improve the stability of the slip friction moment of motor, and simplified product assembly process, the cost is reduced.

Description

Output shaft assembly and motor using same

Technical Field

The utility model relates to the technical field of electric machines, especially, relate to an output shaft assembly and use motor of this output shaft assembly.

Background

The general stepping motor mainly comprises a machine shell assembly, a rotor, a stator assembly, an upper polar plate fixing plate assembly, a gear injection molding body box, an output shaft assembly and a cover plate assembly, wherein the rotor assembly is installed on a middle shaft of the machine shell, the stator assembly is installed inside the machine shell, the upper polar plate fixing plate assembly is installed on the stator assembly, the gear injection molding body box and the output shaft assembly are installed on the upper polar plate fixing plate assembly, and the cover plate assembly is installed on the machine shell assembly and riveted and fixed with each other.

In the prior art, when an output shaft, a friction gasket and a spring gasket are riveted on a stepping motor, the riveting machine axially presses the friction gasket, the part positioned on the radial outer side is pressed towards the other side through a deformation part, the deformation part and a gear injection molding body step form linear elastic contact through generated deformation, so static friction is generated, an output shaft assembly with a friction mechanism is widely used for protecting a gear injection molding body structure in the stepping motor, and the friction gasket, the spring gasket and the friction gasket share the static friction force existing in the gear injection molding body after the riveting pressure is applied to the conventional output shaft assembly with the friction mechanism, so that the friction gasket, the spring gasket and the gear injection molding body are kept to idle under the instant stress of the gear injection molding body, the transmission of the power is blocked, and the purpose of protecting the gear injection molding body is achieved. However, this structure has the following problems:

1. after the motor stress protection mechanism works for too many times, the situation that the sliding friction torque is unstable (durability) exists, so that the motor load stress standard is reduced until the motor fails, and the torque performance of the motor is influenced.

2. The output shaft assembly leads to the output shaft to slightly warp because of the axial effort of riveting pressure in the riveting process, and the gear injection molding body can circumference external expanding after gear injection molding body compression deformation under two-way axial pressure, because of the part among the output shaft assembly warp, after the output shaft takes place axial bending with the skeleton boss locating hole with the assembly of the all the other reduction gear injection molding bodies of motor, the meshing jam of fixed point appears, produces mechanical loss, influences the motor performance.

3. The whole output assembly has more parts, complex assembly process and high cost.

In order to solve the above problems, in the prior art, there is provided a slipping mechanism formed between an output shaft and a gear injection molded body by directly injection molding the output shaft and the gear injection molded body, as disclosed in CN2486784Y, but after the output shaft and the gear injection molded body are injection molded to form the slipping mechanism, there are still many problems in meeting the requirements of friction force and stability.

SUMMERY OF THE UTILITY MODEL

In order to solve among the prior art output shaft assembly durability relatively poor, perhaps can't satisfy the frictional force requirement, take place the technical problem of disconnected tooth because of the instantaneous atress of gear easily, the utility model provides an output shaft assembly and applied this output shaft assembly's motor solves above-mentioned problem.

The utility model provides an output shaft assembly, which comprises an output shaft and a gear injection molding body, wherein the output shaft assembly is formed by the insert injection molding of the output shaft in a gear injection molding body mold; and a shoulder is arranged on the shaft section of the output shaft which is in contact with the gear injection molding body, and the ratio of the radial thickness H4 of the gear injection molding body to the diameter H5 of the shoulder is 3/10-8/3.

Preferably, the number of the shoulder is one or more than one.

Preferably, the output shaft is made of metal.

Preferably, the surface of the output shaft is treated by nickel plating.

Furthermore, the output shaft comprises a first shaft section, a second shaft section and a third shaft section which are sequentially connected along the axial direction, the second shaft section is in contact with the inner periphery of the gear injection molding body, the first shaft section and the third shaft section are respectively located at two ends of the gear injection molding body, and the convex shoulder is located on the second shaft section.

Furthermore, a single-flat or double-flat structure is arranged at one end, far away from the second shaft section, of the first shaft section.

Further, an annular groove is formed between the shoulder and the first shaft section.

Further, the axial height H0 of the annular groove is greater than or equal to 0.5mm, and the radial depth H1 of the annular groove is less than or equal to 1 mm.

Furthermore, the one end of keeping away from the second axle section on the third shaft section is provided with the spindle nose step, the diameter H6 of spindle nose step is 1.4 ~ 1.8 mm.

Furthermore, one end of the third shaft section, which is connected with the second shaft section, is provided with a flat milling step, and the diameter of the flat milling step is larger than that of the shaft head step.

Furthermore, the lower end face of the gear injection molding body is provided with a convex rib.

Furthermore, the lower end face of the gear injection molding body is provided with a sinking step which is sunken upwards, and the injection molding sprue is positioned in the sinking step.

Preferably, the gear injection molding body is injection molded by POM materials.

The utility model also provides a motor, which comprises a casing component, a rotor, a stator component and a gear set, wherein the rotor, the stator component and the gear set are positioned in the casing component; the gear set comprises a plurality of gears in meshed transmission and the output shaft assembly, and the output shaft assembly is positioned at the final stage of the gear set.

Furthermore, the casing subassembly includes casing and apron, the output shaft subassembly passes through the apron stretches out the casing subassembly, be equipped with two mounting holes on the apron, the center of output shaft subassembly and two the center of mounting hole is not on same straight line.

The utility model has the advantages that:

(1) output shaft subassembly insert injection moulding in gear injection moulding body mould by the output shaft, mould plastics through the inserts and make production frictional force and snap-in force between output shaft and the gear injection moulding body to become the mechanism of protection broken tooth in the motor, can guarantee the mechanical strength of output shaft subassembly simultaneously, greatly improve the stability of the slip friction moment of motor, and simplified product assembly process, the cost is reduced.

(2) Output shaft subassembly and applied this output shaft subassembly's motor, with the gear injection molding body contact be equipped with the convex shoulder on the shaft part of output shaft, through reasonable control the gear injection molding body radial thickness H4 with the diameter H5's of convex shoulder proportional relation guarantees on the basis of output shaft intensity, makes the interlock between output shaft and the gear injection molding body evenly balanced more, the output shaft subassembly after the hot injection shaping the static friction and the stability (durability) of kinetic friction moment tend to the superiority.

(3) Output shaft subassembly and applied this output shaft subassembly's motor, the lower terminal surface of gear injection molding body is provided with protruding muscle, reduce all the other gears in the gear train with the utility model discloses the area of contact of well gear injection molding body makes the gear injection molding body reduce rather than the frictional force on other gear surfaces, has reduced mechanical loss.

Drawings

The present invention will be further explained with reference to the drawings and examples.

FIG. 1(a) is a perspective view of an embodiment of an output shaft assembly according to the present invention;

fig. 1(b) is an exploded view of an output shaft assembly according to the present invention;

FIG. 2 is a schematic view of the output shaft as it is being injection molded in the gear injection mold;

FIG. 3 is a schematic diagram of the gripping force and friction between the output shaft and the gear injection molded body after the output shaft assembly is injection molded;

FIG. 4(a) is a schematic cross-sectional view of the output shaft assembly with only one annular groove provided;

FIG. 4(b) is a cross-sectional schematic view of the output shaft assembly (shoulder diameter greater than that of FIG. 4(a))

FIG. 4(c) is a cross-sectional schematic view of the output shaft assembly without the shoulder;

FIG. 5 is a graph of static and dynamic friction moments versus number of operations for the three output shaft assemblies of FIGS. 4(a), 4(b), and 4 (c);

FIG. 6 is a table of high temperature test sliding friction analysis data for various samples with three surface treatments of nickel plating, blackening and phosphating;

FIG. 7 is a table of high temperature test stiction analysis data for various samples under three surface treatments of nickel plating, blackening, and phosphating;

FIG. 8 is a table of data from low temperature test sliding friction analysis of various samples with three surface treatments of nickel plating, blackening and phosphating;

FIG. 9 is a table of cryogenically tested stiction analysis data for a plurality of samples under three surface treatments of nickel plating, blackening and phosphating;

FIG. 10 is a table of cold and hot stamping test sliding friction analysis data for various samples with both nickel and black plating surface treatments;

FIG. 11 is a table of cold and hot stamping test stiction analysis data for various samples with both nickel and black plating;

FIG. 12 is a table of data from a friction durability test sliding friction analysis of various samples with three surface treatments of nickel plating, blackening and phosphating;

FIG. 13 is a chart of stiction durability test stiction analysis data for a plurality of samples under three surface treatments of nickel plating, blackening and phosphating;

fig. 14 is a schematic cross-sectional view of the output shaft assembly of the present invention (the first shaft section is provided with a single flat structure);

FIG. 15(b) is a schematic cross-sectional view of the output shaft assembly with two annular grooves;

FIG. 15(c) is a schematic cross-sectional view of the output shaft assembly with three annular grooves;

FIG. 16 is a third shaft segment sizing view of the output shaft assembly shown in FIG. 1 (a);

FIG. 17 is a schematic view showing the fitting relationship between the steps of the shaft head and the flanging hole of the fixing plate;

FIG. 18 is an enlarged view at N of FIG. 17;

FIG. 19 is a schematic structural view of the gear injection molded body according to the present invention;

fig. 20 is an exploded view of the motor of the present invention;

fig. 21 is a schematic structural view of the gear unit according to the present invention;

fig. 22 is a side view of the motor of the present invention;

fig. 23 is a front view of the motor of the present invention.

In the figure, 1, an output shaft assembly, 101, an output shaft, 1011 a first shaft section, 1012, a second shaft section, 10121, a convex shoulder, 10122, an annular groove, 1013, a third shaft section, 10131, a shaft head step, 10132, a flat milling step, 102, a gear injection molding body, 1021, a convex rib, 1022, a sunken step, 2, a near runner wall, 3, a gear injection molding body mold, 4, a cavity core layer, 5, a fixing plate flanging hole, 6, a fixing plate flanging boss, 7, an injection molding sprue, 8, a rotor, 9, a stator assembly, 10, a gear set, 11, a shell, 12, a cover plate, 1201, a mounting hole, 13, an upper pole plate fixing plate, 14, a middle shaft, 15, a single gear, 16 and a motor wiring harness.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

Example one

As shown in fig. 1(a) -4 (a), an output shaft assembly comprises an output shaft 101 and a gear injection molding body 102, and the output shaft assembly 1 is formed by insert injection molding of the output shaft 101 in a gear injection molding body mold 3; a shoulder 10121 is arranged on a shaft section of the output shaft 101 which is in contact with the gear injection molding body 102, and the ratio of the radial thickness H4 of the gear injection molding body 102 to the diameter H5 of the shoulder 10121 is 3/10-8/3. In this embodiment, the ratio of the radial thickness H4 of gear injection molded body 102 to the diameter H5 of shoulder 10121 is 3/10. One or more of the shoulders 10121 may be provided, and only one shoulder 10121 is provided in the present embodiment.

Make output shaft 101 and gear injection molding 102 become the mechanism of protection broken teeth in the motor through the insert mould plastics, can guarantee output shaft subassembly 1's mechanical strength simultaneously, increase enterprise competitiveness.

The principle of the output shaft assembly 1 for realizing the broken tooth protection is introduced as follows: as shown in fig. 2, the output shaft 101 is injection-molded in the gear injection mold 3, after the insert of the output shaft 101 is hot-injected into a plastic part, because the friction coefficient of the outer surface of the output shaft 101 is high after lathing, the melt of the near-flow passage wall 2 in the injection mold has a temperature difference with the gear injection mold 3, and the cooling speed is fast, the viscosity of the melt of the near-flow passage wall 2 is increased, so that the flow rate of the melt in the core layer 4 of the cavity is much higher than that of the surface layer, the melt is subjected to shear stress between the inner layers, orientation is generated along the flow direction, and certain friction and engagement force are formed between the output shaft 101 and the gear injection mold 102 after injection molding, so that the output shaft 101 can be fixed inside the gear injection mold 102, the output shaft and the gear injection mold 102 cannot rotate radially, and the torque performance of the output shaft assembly 1 is less affected by the number of work. When the output shaft 101 is stressed instantaneously, the instantaneous impact force overcomes the friction force and the biting force between the output shaft 101 and the gear injection molding body 102, so that the output shaft 101 and the gear injection molding body 102 slip, and the phenomenon of tooth breakage of the single gear 15 in the gear set 10 is avoided. In addition, the consistency between the parts of the output shaft 101 after the insert injection molding process is high. As shown in fig. 3, after the output shaft 101 is insert molded, when the plastic is hot injected into the gear injection mold 3, a circumferential wrapping is formed with the output shaft 101 (i.e. the melt wraps the outer circumference of the second shaft section 1012 of the output shaft 101), so that an engaging force and a frictional force are generated at the contact surface of the gear injection mold 102 and the output shaft 101, and the engaging force and the frictional force are denoted by F in fig. 3.

The arrangement of the shoulder 10121 can reasonably increase the distance from the radially farthest point of the output shaft 101 to the center line of the output shaft 101, so that the contact area of the output shaft 101 and plastic is increased, and the radial rotation resistance (static friction force) is improved. On the basis of ensuring the strength of the output shaft assembly 1, the design ensures that the engagement force between the output shaft 101 and the gear injection molding body 102 is more uniformly balanced, and the stability (durability) of the static friction force and the dynamic friction torque of the output shaft assembly 1 after hot injection molding tends to be superior.

The ratio of the radial thickness H4 of the gear injection molded body 102 to the diameter H5 of the shoulder 10121 needs to be reasonably controlled, fig. 5 is static friction torque and dynamic friction torque tests performed on the three output shaft 101 structures of fig. 4(a), 4(b) and 4(c), and it can be seen from fig. 5 that the strength of the output shaft assembly 1 is the lowest under the condition that the shoulder 10121 is not arranged, that is, the static friction torque (c) and the dynamic friction torque (c1) of the output shaft assembly 1 corresponding to fig. 4(c) are the lowest, and the torque performance is rapidly reduced along with the increase of the working times; the strength of the output shaft assembly 1 provided with the shoulder 10121 is obviously greater than that of the output shaft assembly 1 without the shoulder 10121, that is, the static friction moments (a and b) of the output shaft assembly 1 corresponding to fig. 4(a) and 4(b) are greater than the static friction moment (c) of the output shaft assembly 1 corresponding to fig. 4(c), and the dynamic friction moments (a1 and b1) of the output shaft assembly 1 corresponding to fig. 4(a) and 4(b) are greater than the dynamic friction moment (c1) of the output shaft assembly 1 corresponding to fig. 4 (c); if the diameter of the shoulder 10121 is too large, the strength of the output shaft assembly 1 is rather reduced, and the static friction moment (a) and the dynamic friction moment (a1) of the output shaft assembly 1 corresponding to fig. 4(a) are greater than the static friction moment (b) and the dynamic friction moment (b1) of the output shaft assembly 1 corresponding to fig. 4 (b).

The reasons for this phenomenon are: in the case of a limited outer diameter H2 of the gear injection molded part 102 (due to limited gear housing space), if the diameter H5 of the shoulder 10121 is too large, the radial projection thereof in the gear injection molded part 102 will be too large, and the plasticized plastic material will be injected hot because the radial projection will form a small bearing surface stroke, so that it cannot flow back completely due to the high surface tension of the output shaft 101. The shoulder 10121 of the output shaft 101 is as symmetrical as possible while ensuring the uniform and thick wall thickness, further increasing the ability of the output shaft 101 to resist radial rotation (static friction) and the sliding friction with the plastic member. When the diameter H5 of shoulder 10121 is too small, the output shaft 101 is complicated to machine and has reduced strength.

Preferably, the general thickness H3 of gear injection molded body 102 is 3.75-4.75mm, and in this case, the holding force of gear injection molded body 102 to output shaft 101 is larger, the friction force is more stable, and the durability is better. In this embodiment, the gear injection molded body 102 has a thickness H3 of 3.75 mm.

In this embodiment, the output shaft 101 is preferably made of a metal material, and the metal structure is convenient to machine, high in machining precision, high in rigidity, small in metal relative expansion coefficient, and less affected by temperature.

Furthermore, in order to protect the surface of the output shaft 101 made of a metal material, the output shaft 101 is often required to be subjected to surface treatment, the conventional process is blackening and phosphating, the embodiment breaks through the bias of the prior art, nickel plating is performed on the surface of the output shaft 101, the surface roughness of the output shaft 101 after machining is improved, the metal piece subjected to the nickel plating treatment is good in antirust performance, the problem of injection molding stress concentration caused by unstable surface roughness of the output shaft 101 after machining is solved, and the friction torque stability of the output shaft assembly 1 after injection molding is good. Fig. 6-13 respectively carry out high and low temperature tests, cold and hot stamping tests and friction durability tests on a plurality of sampled products, and it is obvious from the several figures that the products treated by nickel plating have the best consistency and stability under different tests, so that the output shaft assembly 1 obtained by the nickel plating surface treatment mode has improved antirust performance and better friction torque stability.

In this embodiment, the gear injection molded body 102 is injection molded by using a POM material, and the POM injection molded gear injection molded body 102 has high mechanical strength, rigidity and environmental resistance, and also has good dimensional stability, elasticity, self-lubrication and wear resistance, and the friction torque stability of the output shaft assembly 1 after insert injection molding is high.

Example two

In addition to the first embodiment, as shown in fig. 3 and 4(a), the output shaft 101 includes a first shaft section 1011, a second shaft section 1012 and a third shaft section 1013 that are sequentially connected in the axial direction, the second shaft section 1012 contacts with the inner periphery of the gear injection molded body 102, the first shaft section 1011 and the third shaft section 1013 are respectively located at two ends of the gear injection molded body 102, and the shoulder 10121 is located on the second shaft section 1012.

First shaft section 1011: the first shaft section 1011 at an end remote from the second shaft section 1012 is provided with a single flat (as shown in figure 14) or double flat configuration (as shown in figure 3) for connection to an external drive end. The output shaft assembly 1 is installed on the motor, and the motor forms transmission structure with the transmission of the moment of being convenient for after the external assembly, increases flat potential on the output shaft assembly 1, can form peripheral radial spacing. The torque transmission is realized through the flat structure, the assembly is simple and convenient, the torque transmission device can be used in cooperation with different product structures, and the stability is good.

Second shaft segment 1012: the second shaft section 1012 is provided with a shoulder 10121 protruding radially outward, the shoulder has a circular cross section, an annular groove 10122 is formed between the shoulder 10121 and the first shaft section 1011, when there is only one shoulder 10121 on the second shaft section 1012, only one annular groove 10122 is located above the shoulder 10121, when there are a plurality of shoulders 10121 on the second shaft section 1012, adjacent shoulders 10121 are spaced apart from each other, so that there are one annular groove 10122 between adjacent shoulders 10121 and between the uppermost shoulder 10121 and the first shaft section 1011, there is only one annular groove 10122 on the output shaft 101 shown in fig. 4(a), there are two annular grooves 10122 on the output shaft 101 shown in fig. 15(b), and there are three annular grooves 10122 on the output shaft 101 shown in fig. 15 (c).

As shown in the static friction moment and the dynamic friction moment of the output shaft assembly 1 in the three output shaft 101 structures of fig. 4(a), fig. 15(b), and fig. 15(c), the stability (durability) of the output shaft assembly 1 is the best when one annular groove 10122 is provided, mainly because: the output shaft 101 is a metal part, and the expansion coefficient of the metal part is greatly different from that of the plastic (the gear injection molded body 102), when the output shaft 101 is cooled by injection molding, the shrinkage levels of the two components are different, when the output shaft 101 is subjected to hot injection molding, the outer layer of the plastic product is cooled, solidified and shrunk firstly, while the inner layer of the plastic article may still be a hot melt, the core layer may limit the shrinkage of the surface, resulting in a condition of compressive stress on the core layer, while too many annular grooves 10122 may result in a decrease in the distance between adjacent annular grooves 10122, because the surface is in a tensile stress state, the product is easy to crack and bubble, in order to ensure the uniform injection wall thickness in the whole injection molding process, the number of the annular grooves 10122 on the output shaft 101 is designed to be one under the limitation of small injection space, poor injection caused by small width of the annular grooves 10122 due to excessive number is prevented, and the possibility of cracking of the gear injection molded body 102 is greatly reduced.

To ensure the strength of the output shaft 101 and due to the limitation of the machining process, the axial height H0 and the radial depth H1 of the annular groove 10122 need to be reasonably controlled (as shown in fig. 4(a)), specifically because: if the axial height H0 of the annular groove 10122 is too small, the machining difficulty coefficient is too high, and the service life of the tool is shortened, preferably, the axial height H0 of the annular groove 10122 is greater than or equal to 0.5 mm; if the radial depth H1 of the annular groove 10122 is too large, scrap iron is left in the annular groove 10122, the injection molding of the assembly is affected, the friction force of the output shaft assembly 1 is unstable and even fails, and in addition, the plastic wall thickness around the output shaft 101 is ensured to be large enough, the internal stress around the insert is reduced, the possibility of cracking of the gear injection molding body 102 is reduced, and preferably, the radial depth H1 of the annular groove 10122 is less than or equal to 1 mm.

Third shaft segment 1013: (1) as shown in FIG. 16, a shaft head step 10131 is provided on one end of the third shaft section 1013 away from the second shaft section 1012, and the diameter H6 of the shaft head step 10131 is 1.4-1.8 mm. As shown in fig. 17 and 18, when the output shaft assembly 1 is assembled into a motor, the shaft head step 10131 is positioned with a fixing plate flanging hole 5 of the motor, the fixing plate flanging boss 6 is arranged at the fixing plate flanging hole 5, the smaller the height H7 of the fixing plate flanging boss 6, the larger the stress at the bending part, the bending deformation and the shortened service life of the die are caused, if the height H7 of the fixing plate flanging boss 6 is too large, the fixing plate flanging boss 6 interferes with a single gear 15 in a gear set 10, so the height of the fixing plate flanging boss 6 is limited, the diameter H6 of the shaft head step 10131 is 1.4-1.8 mm (the relationship between the diameter of the shaft head step 10131 and the flanging boss height is that the larger the diameter of the shaft head step 10131 is, the larger the inner diameter of the fixing plate flanging hole 5 is, the higher the height of the fixing plate flanging boss 6 is determined by the processing technology of the fixing plate flanging hole 5, the fixing plate flanging hole 5 and the flanging boss 6 are formed by punching), the height H8 of the shaft head step 10131 must be higher than the height H7 of the fixed plate flanging boss 6, so that the shaft head step 10131 is prevented from contacting the fixed plate flanging boss 6 to form surface-surface contact, the abrasion and mechanical loss of the shaft head step 10131 are caused, and the whole service life and performance noise of the whole machine are influenced.

(2) As shown in fig. 16, one end of the third shaft section 1013 connected to the second shaft section 1012 is provided with a flat milling step 10132, the flat milling step 10132 is connected to the shaft head step 10131, a diameter of the flat milling step 10132 is greater than a diameter of the shaft head step 10131, the flat milling step 10132 is to mill a plane on a circumferential surface of the cylindrical step structure, and the diameter of the flat milling step 10132 is to mill a diameter of the cylindrical step structure. Preferably, the diameter H9 of the milling flat step 10132 is 1.4-2.5 mm. In the machining process of the output shaft 101, the machining of different positions needs to be carried out after positioning, and under the premise that the strength of the output shaft 101 is ensured, the front end of the third shaft section 1013 is milled flat, so that the part machining positioning effect is achieved, the machining process is simplified, the cost is reduced, and the market competitiveness of the motor is improved.

EXAMPLE III

In addition to the first or second embodiment, as shown in fig. 19, a rib 1021 is provided on the lower end surface of the gear injection molded body 102. When the output shaft assembly 1 is assembled on the motor, because the internal parts of the motor are composed of a gear box and the like, according to different installation modes of the motor, the phenomenon that the lower surface of the gear injection molded body 102 is in surface contact with the single gear 15 exists, the convex ribs 1021 are added to enable the gear injection molded body 102 to be in surface line-surface contact with the single gear 15, the friction resistance between the gear injection molded body 102 and the adjacent single gear 15 surface is reduced, the abrasion between the gear injection molded body 102 and the adjacent single gear 15 surface is reduced, and the mechanical loss is reduced.

Example four

In addition to the first embodiment, the second embodiment or the third embodiment, as shown in fig. 16 and 19, the lower end surface of the gear injection molded body 102 has a depressed step 1022 depressed upward, and the injection gate 7 is located in the depressed step 1022.

A sunken step 1022 with a certain depth is arranged on the lower end surface of the gear injection molded body 102, and an injection gate 7 is arranged in the sunken step 1022, so that even if burrs exist at the position of the injection gate 7, the interference between the gear injection molded body 102 and other parts is not influenced.

The gate location determines the flow profile, flow spacing and flow direction of the plastic melt in the mold cavity. If the size of runner is undersize, can make and fill the mould time extension, the injection molding body cools off great difference in the shrink that inhomogeneous arouses to after the fuse-element got into the die cavity, the temperature reduction quickens, and the fuse-element viscosity increases rapidly, causes to fill the mould under the high viscosity, thereby increase cooling internal stress and orientation stress, leads to the injection molding body also to have the hidden danger of scarce material. When the injection gate 7 is disposed at the position with the largest injection wall thickness (the surface of the sunken step 1022), the injection pressure, the holding pressure and the holding time are appropriately reduced, which is beneficial to reducing the orientation stress of the gear injection molded body 102. And the burr of the injection molding sprue 7 is lower than the lower surface of the gear injection molding body 102, so that the contact interference with other parts is prevented.

The selection of 7 reasonable positions of runner of moulding plastics is passed through to this embodiment, and the effectual bad hidden danger of moulding plastics that has avoided moulding plastics to bring improves product stability.

EXAMPLE five

An electrical machine comprising a housing assembly and, located within the housing assembly, a rotor 8, a stator assembly 9 and a gear set 10; the gear set 10 comprises a multi-stage single gear 15 and the output shaft assembly 1, wherein the multi-stage single gear is in meshed transmission with the multi-stage single gear, and the output shaft assembly 1 is located at the final stage of the gear set 10.

The components inside the casing assembly are the same as those of the stepping motor in the prior art, as shown in fig. 20, the rotor 8 is mounted on the middle shaft 14, the stator assembly 9 is mounted inside the casing, the upper pole plate fixing plate 13 assembly is mounted on the stator assembly 9, and the gear set 10 is mounted on the upper pole plate fixing plate 13 assembly, wherein the output shaft assembly 1 of the present embodiment is different from the output shaft assembly 1 in the prior art.

In the gear set 10, the output shaft assembly 1 is disposed at the last stage (as shown in fig. 21), because the output shaft assembly 1 is a friction mechanism, when the output end of the motor is subjected to an impact load, the gear injection molded body 102 of the output shaft assembly 1 slides and rubs to generate idle rotation, thereby blocking the transmission of power and achieving the purpose of protecting the single gear 15. If the friction mechanism is arranged on other non-final-stage transmission gears, because the final-stage gear is stressed and the teeth are broken without transmitting the load force to the previous-stage gear, the output shaft assembly 1 arranged on the final stage can effectively protect the single gear 15.

The casing assembly comprises a casing 11 and a cover plate 12, the output shaft assembly 1 extends out of the casing assembly through the cover plate 12, two mounting holes 1201 are formed in the cover plate 12, and the center of the output shaft assembly 1 and the centers of the two mounting holes 1201 are not on the same straight line.

The output shaft assembly 1 extending out of the surface of the cover plate 12 is a first shaft section 1011 of the output shaft 101, and is used for being assembled with a client to form a transmission mechanism, so that a power transmission effect is achieved.

The mounting hole 1201 is usually located on the central horizontal line of the motor, the output shaft assembly 1 is located on the upper portion of the central horizontal line of the motor and is not located on the same straight line with the mounting hole, the output shaft assembly 1 and the mounting hole 1201 form a stress surface, the stress of the cover plate 12 can be greatly loaded on the formed stress surface in the fastening process, and the mounting plate (the mounting hole 1201 is located on the mounting plate) of the cover plate 12 cannot be deformed (as shown in fig. 22) due to uneven stress, so that the quality of the motor is improved. In addition, the output shaft assembly 1 and the motor wiring harness 16 are respectively positioned at two sides of the motor (as shown in fig. 23), so that the installation at a client side is convenient.

In the description of the present invention, it is to be understood that the terms "central", "upper", "lower", "horizontal", "inner", "outer", "axial", "radial", "circumferential", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are used merely for convenience of description and simplification of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In this specification, the schematic representations of the terms are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments.

In light of the foregoing, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims (13)

1. An output shaft assembly characterized by: the gear injection molding device comprises an output shaft (101) and a gear injection molding body (102), wherein the output shaft assembly (1) is formed by insert injection molding of the output shaft (101) in a gear injection molding body mold (3); a shoulder (10121) is arranged on a shaft section of the output shaft (101) which is in contact with the gear injection molding body (102), and the ratio of the radial thickness H4 of the gear injection molding body (102) to the diameter H5 of the shoulder (10121) is 3/10-8/3.

2. The output shaft assembly of claim 1, wherein: the number of the shoulders (10121) is one or more than one.

3. The output shaft assembly of claim 1, wherein: the output shaft (101) is made of a metal material, and the surface of the output shaft (101) is subjected to nickel plating treatment.

4. The output shaft assembly of claim 1, wherein: the output shaft (101) comprises a first shaft section (1011), a second shaft section (1012) and a third shaft section (1013) which are sequentially connected along the axial direction, the second shaft section (1012) is in contact with the inner periphery of the gear injection molded body (102), the first shaft section (1011) and the third shaft section (1013) are respectively positioned at two ends of the gear injection molded body (102), and the shoulder (10121) is positioned on the second shaft section (1012).

5. The output shaft assembly of claim 4, wherein: one end of the first shaft section (1011) far away from the second shaft section (1012) is provided with a single-flat or double-flat structure.

6. The output shaft assembly of claim 4, wherein: an annular groove (10122) is formed between the shoulder (10121) and the first shaft section (1011), the axial height H0 of the annular groove (10122) is greater than or equal to 0.5mm, and the radial depth H1 of the annular groove (10122) is less than or equal to 1 mm.

7. The output shaft assembly of claim 4, wherein: and a shaft head step (10131) is arranged at one end, far away from the second shaft section (1012), of the third shaft section (1013), and the diameter H6 of the shaft head step (10131) is 1.4-1.8 mm.

8. The output shaft assembly of claim 7, wherein: one end of the third shaft section (1013) connected with the second shaft section (1012) is provided with a milling flat step (10132), and the diameter of the milling flat step (10132) is larger than that of the shaft head step (10131).

9. The output shaft assembly of claim 1, wherein: and a convex rib (1021) is arranged on the lower end surface of the gear injection molding body (102).

10. The output shaft assembly of claim 1, wherein: the lower end face of the gear injection molding body (102) is provided with a sunken step (1022) which is sunken upwards, and the injection molding gate (7) is positioned in the sunken step (1022).

11. The output shaft assembly of claim 1, wherein: the gear injection molding body (102) is formed by injection molding of a POM material.

12. An electric machine comprising a housing assembly and a rotor (8), stator assembly (9) and gear set (10) located within the housing assembly; the gear set (10) comprises a multi-stage single gear (15) and the output shaft assembly (1) of any one of claims 1 to 11, which are in meshed transmission, and the output shaft assembly (1) is located at the last stage of the gear set (10).

13. The electric machine of claim 12, wherein: the casing assembly comprises a casing (11) and a cover plate (12), the output shaft assembly (1) extends out of the casing assembly through the cover plate (12), two mounting holes (1201) are formed in the cover plate (12), and the center of the output shaft assembly (1) and the centers of the two mounting holes (1201) are not on the same straight line.

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