Patent Application
20190002254
The present disclosure is directed generally to winches with axially aligned brakes, and associated systems and methods.
Winches have been used for years in a variety of industries, including the automotive industry, and more particularly, the off-road vehicle industry. When used on off-road vehicles, winches can allow the vehicle operator to pull the vehicle out when it is stuck, guide the vehicle down a steep slope in a controlled manner, and/or move other vehicles or objects, depending upon the particular application.
While the forgoing designs are generally operable for their intended purposes, they may suffer from one or more drawbacks that are described in further detail later.
Embodiments of the present technology are directed generally to winches with axially aligned brakes, and associated systems and methods. In particular embodiments, winches having one or more of the features described herein can provide several advantages over existing winches. For example, the winches can provide a more compact shape that can provide for functional and/or aesthetic benefits. Brakes in accordance with particular embodiments of the present technology can be coupled to winches at a variety of suitable points, including directly adjacent a winch motor, and/or at one or more positions in the winch transmission. Embodiments of the winch can be particularly configured to avoid engaging the brake unnecessarily, which can wear out the brake, and/or create unnecessary heat in the environment in which the brake operates.
Several details describing structures and/or processes that are well-known and often associated with winches, but that may unnecessarily obscure some significant aspects of the present technology, are not set forth in the following description for purposes of clarity. Moreover, although the following disclosure sets forth several embodiments of different aspects of the technology, several other embodiments of the technology can have different configurations and/or different components than those described in this section. As such, the technology may have other embodiments with additional elements, and/or without several of the elements described below with reference to
During a normal winching operation, the drive motor 203 drives the drum 201 via the transmission 220. When the operator wishes to strip or unwind the cable 202 from the drum 201, the operator disengages the clutch 210 to allow the drum 201 to easily rotate in the opposite direction, without resistance provided by the transmission 220 or the drive motor 203.
In another mode of operation, the drive motor 203 can remain engaged with the drum 201 (via the transmission 220) while the cable 202 is unwound from the drum 201. This mode of operation can be used, for example, to back a vehicle down a steep slope, with a restraining force provided by the winch 200. During such operations (typically referred to as “powering out”), it is desirable to provide a braking force without unnecessarily wearing the brake. Suitable techniques for this operation are described further later.
In a particular embodiment, the transmission 220 includes a gear train 221 that in turn includes a multi-stage planetary gear arrangement. In some embodiments, the gear train 221 can include a first stage 222a, a second stage 222b, and a third stage 222c. In a particular embodiment shown in
In representative embodiments, the planetary gear arrangement can produce a significant gear reduction, e.g., about 155:1. Each of the planetary gears stages 222a, 222b, 222c can include a corresponding sun gear 225a, 225b, 225c, corresponding planet gears 226a, 226b, 226c, and a corresponding ring gear 227a, 227b, 227c. When the clutch 210 is engaged, a clutch shaft 212 engages with the second stage ring gear 227b, thus grounding the second stage ring gear 227b and allowing the rotary motion of the drive shaft 205 to be transmitted to the output shaft 224 via the transmission 220. When the clutch shaft 212 is disengaged from the second stage ring gear 227b, the output shaft 224 (and therefore the drum 201, shown in
As shown in
The first element 231 is journaled to the first sun gear 225a, and the second element 232 is fixed to the drive shaft 205. Accordingly, when the brake 230 is engaged, with the friction element 233 clamped between the first element 231 and the second element 232, the drive shaft 205 drives the first stage sun gear 225a. The first element 231 includes first element threads 240 that threadably engage with second element threads 241 carried by the second element 232. Accordingly, relative rotary motion between the first and second elements 231, 232 in one direction causes the first element to clamp the friction element 233 to the second element 232, and relative rotary motion in the opposite direction causes the first element 231 to unclamp the friction element 233. When the brake 230 is disengaged, the friction element 233 can be supported on a shoulder 236 of the first element 231. The second element 232 can include retention threads 237 that threadably engage a retention nut 238 to prevent the first element 231 from moving too far to the left, as shown in
The brake 230 can further include a locking element that selectively engages the brake disc 234. For example, the locking element can include pawls (described further below with reference to
If the operator then “powers out” by driving the winched vehicle away from the winch anchor point, while the clutch 210 is engaged, and the motor 203 is powered and rotating in the reverse direction, the first element 231 (which is coupled to the drum) is allowed to rotate relative to the second element 232 (which is coupled to the motor) to unclamp the friction element 233. If the drum turns too fast relative to the motor, the difference in rotation rate between the first element 231 and the second element 232 causes the first element 231 to again clamp the friction element 233 against the second element 232. In this manner, the brake 230 effectively governs the rate at which the winched load (e.g., the vehicle) can be powered out.
During the foregoing process, the brake 230 periodically engages and disengages to prevent excessive drum speed, but is consistently either engaged or disengaged. This is unlike some conventional braking arrangements in which the brake is continuously engaged, but is overdriven so that it is constantly slipping and wearing, which creates excessive heat and brake wear. In some instances, a brake used in this continuously engaged fashion can become glazed, which can effectively eliminate the effectiveness of the brake for any operation—not just powering out, but also simply holding the winched load in place. Accordingly, brakes operating in accordance with embodiments of the present technology can provide one or more significant advantages over existing brakes, including reduced brake wear, increased brake life, and increased brake effectiveness. In addition, the axis about which the brake 230 operates is the same as the shaft axis 206. Accordingly, the brake 230 can have a minimal impact on the overall envelope or shape of the winch. In particular, this approach can reduce or eliminate the bulge 9 described above with reference to
The brake 230 can form a sub assembly 247 (e.g., a packet or cassette) that is specifically configured for easy removal from the winch. For example, the first housing member 243a, the bearing 248, the second element 232, the friction element 233, the first element 231, the pawls 244 and associated pawl pins 245 and pawls springs 246, the second housing member 243b and the first stage sun gear 255a can be removed, e.g., as a single unit. The ability to remove the foregoing elements as a unit can improve serviceability of the winch 200. In the event that the brake 230 is permanently removed and not replaced, the first stage sun gear 255a (or other connecting element) will typically be replaced with another suitable connecting element because the brake 230 forms the connection between the motor shaft and the transmission.
As is also shown in
One feature of at least some of the foregoing embodiments is that the brake operates automatically via mechanical actuation. That is, the brake automatically engages or disengages in the manner described above, without the need for a separate actuator, such as an electric actuator or a hydraulic actuator. Instead, the mechanical forces provided by the winch and the brake elements during a winching operation and a power-out operation automatically engage and disengage the brake.
Another feature of at least some of the foregoing embodiments is that the brake operates in a binary manner between an engaged configuration and disengaged configuration. This feature can reduce or eliminate the likelihood for excessive wear on the brake, e.g., because it is less wearing to fully engage and fully disengage the brake (with little or no relative movement between the brake pads and the first and second brake elements when engaged) than it is to partially engage the brake (while the first and second elements slip relative to each other and wear the brake pads). This operation can have particular utility during a power-out operation, as discussed above. In at least some embodiments, the bulk of the task of braking the vehicle during a power-out operation can be performed by the vehicle's brakes, which are more suited to such a task than are the relatively smaller brakes of a typical vehicle winch.
Another feature of at least some of the foregoing embodiments is that the brake is axially aligned with the motor drive shaft. An advantage of this arrangement is that it can reduce the number of components required by the brake (e.g., by eliminating the need for an off-axis spur gear). Another advantage is that the overall winch can be made more compact and uniform, which can reduce the amount of space occupied by the winch, and/or can provide a cleaner looking product.
Another feature of at least some of the foregoing embodiments is that the brake is positioned external to the cable drum. An advantage of this arrangement is that it is less likely to heat the drum. Another advantage is that the brake can be more easily accessed for maintenance, repair, and/or replacement.
From the foregoing, it will be appreciated that specific embodiments of the disclosed technology have been described herein for purposes of illustration, but that various modifications may be made without deviating from the technology. For example, the brake can be coupled to the first stage of a multi-stage planetary gear transmission (as shown in
Certain aspects of the technology described in the context of particular embodiments maybe combined or eliminated in other embodiments. For example, one or more of the planetary gear stages can be eliminated in some embodiments. In some embodiments, the brake can be connected to a different stage of the transmission (e.g., the second stage) where rotational velocities and associated forces (e.g., centrifugal forces) are lower. Further, while advantages associated with certain embodiments of the disclosed technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the present technology. Accordingly, the present disclosure in the associated technology can encompass other embodiments not expressly shown or described herein.
